包裹法制备BaTiO3基半导体陶瓷电容器
The electrical properties of the surface layer ceramic capacitor of Y5V based BaTiO3 synthesized with coprecititation first doped with Nd3+ with different concentration (0.030 to 0.065) were investigated.The way of special coprecititation was adopted, the principle as follows:+2NH4Cl+CO2↑ +H2Ot +3H2OBaCl2 reacts with NH4HCO3 to make BaCO3, BaCO3 wraps around TiO2 particles as nucleus. Rear earth ions were first doped, so this way is heterogeneous coprecititation. The reaction products react to produce salt titanate when it is calcined.The powder was calcined at 1160℃, the granularity is about 2-5μm by the laser granularity analyzing, the granularity distribution is centralized. The ceramic pieces was made as the size of diameter 10mm and the thickness lmm. The powder and the pieces are all tetragonal phase. The lattice parameter is varied with the Ball Neodymium Magnets different doping elements;the 111 and 200 faces have obvious lattice tropism.The ceramic pieces were sintered at different temperature and heat preserved for different hours, It is found that it is the best condition sintered at 1360°C and heat preserved for 3 hours. The ceramic is insulating behavior and its dielectric constant ε is greatly increased doping with high concentration of Nd3+. A corresponding increase in the ε, decrease in the courier temperature Tc and insulating waste tan 6 of the latent ceramic With the increase of Nd3+concentration at the range of 0.030-0.055;Inflexion appears at the 0.055-0.060 of the concentration of Nd3+. Contrasting the samples of Ba1-xNdxTiO3 to Ba1-3/2xNdxTiO3, the electrical properties of the samples of the Ba1-3x/2NdxTiO3 is better than those of Ba1-xNdxTiO3 because the samples of Ba1-3x/2NdxTiO3 is electrovalence equilibrium. The ε increase greatly and the Tc decrease together with Zr4+. It has little influence on the electrical properties with MnCO3 in the BaTiO3 ceramic. The electricalproperties of ceramic capacitor based BaTiC^ synthesized with coprecititation first doping with Nd3+ with Sm3+ or Er3+ with different concentration (0.040 to 0.050) were investigated.
The e decrease greatly and the Tc increase doped with Sm3+ or Er3+. It is the best when the concentration is 25% of Sm3+or Er+. After the ceramic pieces being reducted-reoxidated, the electrical properties of ceramic capacitor doping with only Nd3+ is not ideal because the materials has not enough anti-reduction. The electrical properties of ceramic capacitor doping together with Zr4+ become better much and the insulating resistance R reach 500MQ, it is showed that ceramic has some anti-reduction. The insulating resistance R reach more than 1000M Q http://www.chinamagnets.biz of the ceramic doping together with Mn2+, it showed that Mn2+ had great anti-reduction. The latent dielectric constant e of the ceramic doping with two donors is about 3000 but the insulating resistance R can reach more than 500M Q. The reason is that crystal state of the materials become better, it can improve the quality of the insulation layer when the granularity of the powder become smaller. In generally, the crystal grain need more grow up if we want dielectric constant bigger, but the density of the ceramic can increase and the thickness the insulation layer can become more thin if the crystal grain become smaller, this is equal to increase the dielectric constant to make the electrical properties of ceramic become better. The experiments results just match our intention.Eventually , using the special wrapping way, the electrical properties of the ceramic can reach: The insulating resistance can reach more than 1000M Q, the ratio capacitance C/S = 0.5498 uf/cm2, tan 6 ( x 10"4) less than 400. Our experiments established the foundation of industry applying. This way can be used not only in other II ceramic but also the ceramic capacitor based SrTiC>3 besides surface layer ceramic capacitor based BaTiC>3, So the success of this way has great significance.
2012年8月27日星期一
Study on Low-Speed and High-Torque Gearless Drive System
Study on Low-Speed and High-Torque Gearless Drive System
Nowadays, permanent magnetic synchronous motors (PMSM) are used very widely in many industry fields, especially in elevators and high precision servo systems, because of their advanced performances beyond other motors. What’s more, permanent strong magnets magnet material-rare earth is very rich in our nation;therefore, doing research on the control system for PMSM has great science significance and application value.This paper introduces a novel gearless drive system of low-speed and high-torque (LSHT) PMSM for elevator. It that supplied with spatial vector pulse width modifying (SVPWM) inverter can directly drive elevator without decelerator. This direct drive of elevator has not only simplified the construction of transmission mechanism which improved transmit power density and efficiency of the drive system, but also increased precision and reliability of the control system. In this system, rotor position observation is innovative point which avoids a lot of questions caused by mechanic sensor.On the theory, according to the mathematic model of PMSM, the paper presents and realizes i_d = 0 control strategy after analyzing the advantage and disadvantage of diversifiedcontrol strategies. Based on low-speed motor drive system, the design adopts a novel approach of rotor speed/position estimation based on adaptive control. Furthermore, it introduces SVPWM technology in http://www.chinamagnets.biz order to reduce harmony of the system. This paper uses the simulation software MATLAB/Simulink to simulate the drive system of low speed and high torque PMSM and the results show that the system models are rightly built and control strategy is feasible. On the basis of hardware TMS320LF2407 of PMSM control system, the paper composes the complete control software using assembly language and realizes stator phrase current sampling, phrase voltage calculation, rotor speed/position observation and output of drive signal. Finally, the inverter-motor model drive system of 1 lkW PMSM is successfully designed and the data of experiment verifies that the proposed vector control scheme is valid, and the dynamic and static performances are quite well. Furthermore, the propose strategy has stronger robustness.
Nowadays, permanent magnetic synchronous motors (PMSM) are used very widely in many industry fields, especially in elevators and high precision servo systems, because of their advanced performances beyond other motors. What’s more, permanent strong magnets magnet material-rare earth is very rich in our nation;therefore, doing research on the control system for PMSM has great science significance and application value.This paper introduces a novel gearless drive system of low-speed and high-torque (LSHT) PMSM for elevator. It that supplied with spatial vector pulse width modifying (SVPWM) inverter can directly drive elevator without decelerator. This direct drive of elevator has not only simplified the construction of transmission mechanism which improved transmit power density and efficiency of the drive system, but also increased precision and reliability of the control system. In this system, rotor position observation is innovative point which avoids a lot of questions caused by mechanic sensor.On the theory, according to the mathematic model of PMSM, the paper presents and realizes i_d = 0 control strategy after analyzing the advantage and disadvantage of diversifiedcontrol strategies. Based on low-speed motor drive system, the design adopts a novel approach of rotor speed/position estimation based on adaptive control. Furthermore, it introduces SVPWM technology in http://www.chinamagnets.biz order to reduce harmony of the system. This paper uses the simulation software MATLAB/Simulink to simulate the drive system of low speed and high torque PMSM and the results show that the system models are rightly built and control strategy is feasible. On the basis of hardware TMS320LF2407 of PMSM control system, the paper composes the complete control software using assembly language and realizes stator phrase current sampling, phrase voltage calculation, rotor speed/position observation and output of drive signal. Finally, the inverter-motor model drive system of 1 lkW PMSM is successfully designed and the data of experiment verifies that the proposed vector control scheme is valid, and the dynamic and static performances are quite well. Furthermore, the propose strategy has stronger robustness.
Research and Development of Premium-efficiency Permanent Magnet Synchronous Motor
Research and Development of Premium-efficiency Permanent Magnet Synchronous Motor
As a sub- project of national science and technology key project——"The Research andDevelopment of High Performance Rare Earth Permanent Magnet Machine ", this paper presents the research on several key questions of designing premium-efficiency permanent magnet synchronous motor uses in the fan or pump ,such as efficiency, power factor, pull-out torque and so on. The achievement that has value in the Engineering is obtained.First of all, in this paper the rare earth magnets influence of the fan on the efficiency of motor is analyzed. As the premium-efficiency permanent magnet motor used in the fan and the pump, the rotating speed of motor is high, the influence of the fan on the efficiency of the motor is extremely obvious. The loss of traditional centrifugal fan is approximately 3% of total loss in 2 pole-pair motor. Therefore, in this article the characteristics and the merits of axial-flow fan are used, substituting the axial-flow fan for traditional centrifugal fan.
According to the theoretical calculation and the experimental confirmation, those measures receive good effect.Next, in the process of researching how to enhances the efficiency of motor, in this paper the time-stepping finite element method is used, the calculation formula has modified, achieved good effect, the theory basis for later calculation of iron loss of permanent magnet motor is found. Meanwhile, detail analysis and research on the factors that have influence on the iron loss, the copper loss and the stray losses are conducted, the corresponding measures are taken in order to reduce these kinds of losses.Then, through synthesis considering of these factors, the optimized http://www.chinamagnets.biz design of two types of motors is carried in anneal arithmetic. The optimized design of the stator lamination mainly aims for minimizing the sum of the copper loss and the iron loss. The optimized design of the rotor is taken mainly including the rotor magnetic circuit, the shape of rotor slot, magnetic bridge, etc. At the same time, the air gap length of the motor is also optimized.Finally, prototypes of permanent magnet motor of two specifications are developed.The prototypes have achieved the anticipated effect and passed the appraisal, the conclusion is "theinternational leading level". Meanwhile, it also proves that the achievement has an important value in practical application.
As a sub- project of national science and technology key project——"The Research andDevelopment of High Performance Rare Earth Permanent Magnet Machine ", this paper presents the research on several key questions of designing premium-efficiency permanent magnet synchronous motor uses in the fan or pump ,such as efficiency, power factor, pull-out torque and so on. The achievement that has value in the Engineering is obtained.First of all, in this paper the rare earth magnets influence of the fan on the efficiency of motor is analyzed. As the premium-efficiency permanent magnet motor used in the fan and the pump, the rotating speed of motor is high, the influence of the fan on the efficiency of the motor is extremely obvious. The loss of traditional centrifugal fan is approximately 3% of total loss in 2 pole-pair motor. Therefore, in this article the characteristics and the merits of axial-flow fan are used, substituting the axial-flow fan for traditional centrifugal fan.
According to the theoretical calculation and the experimental confirmation, those measures receive good effect.Next, in the process of researching how to enhances the efficiency of motor, in this paper the time-stepping finite element method is used, the calculation formula has modified, achieved good effect, the theory basis for later calculation of iron loss of permanent magnet motor is found. Meanwhile, detail analysis and research on the factors that have influence on the iron loss, the copper loss and the stray losses are conducted, the corresponding measures are taken in order to reduce these kinds of losses.Then, through synthesis considering of these factors, the optimized http://www.chinamagnets.biz design of two types of motors is carried in anneal arithmetic. The optimized design of the stator lamination mainly aims for minimizing the sum of the copper loss and the iron loss. The optimized design of the rotor is taken mainly including the rotor magnetic circuit, the shape of rotor slot, magnetic bridge, etc. At the same time, the air gap length of the motor is also optimized.Finally, prototypes of permanent magnet motor of two specifications are developed.The prototypes have achieved the anticipated effect and passed the appraisal, the conclusion is "theinternational leading level". Meanwhile, it also proves that the achievement has an important value in practical application.
2012年8月23日星期四
粉体还原和块体烧结条件对La0.67Sr0.23-xCu0.10□xMnO3(x=0，0.03)材料磁性和电输运性能的影响
粉体还原和块体烧结条件对La0.67Sr0.23-xCu0.10□xMnO3(x=0，0.03)材料磁性和电输运性能的影响
Since the 1990’s, When the colossal magnetoresistance (CMR) effect in rare-earth manganite perovskites was found, it has attracted considerable attention of scientists and engineers due to its special physics mechanism and the potential application in fields of magnetic record and magnetic sensor and so on.However, the poor temperature dependence of magnetoresistance (MR), the ideal MR occurred only in high field and the low-temperature for the most materials, severely limit their practical utilities. Many researches have thus been concentrated on making new material system that provides low field magnetoresistance (LFMR) around room temperature. On the other hand, recent efforts to broaden the CMR temperature range have been made Segment neodymium magnets by means of the Mn-site substitution or oxygen-deficiency.In this paper, La0.67Sr0.23-xCu0.10□xMnO3(x=0,0.03) polycrystalline powders were prepared by sol-gel method, which we used as parent materials. The parent powders were reduced by hydrogen in different conditions, and series of reduced powders were prepared. The bulk samples sintered in an Ar and air atmosphere respectively. Their structure, morphology, electrical and magnetic properties as well as magnetoresistance were researched in detail. There are several results we have got:1. Morphologies of La0.67Sr(0.23-x)Cu0.10□xMnO3(x=0, 0.03) parent powders and reduced powders were obtained by S-570 scanning electron microscopy (SEM). The results show that the particles in powder samples are closed to globular shape and the particle size is nanometer order. The phenomenon of conglobation in particles was improved by reducing treatment.2. The phase identification of samples has been carried out by the X-ray diffraction (XRD) with a Rigaku DMax(12KW) diffractometer. The results indicate that the Mn3O4 impurity phase in the samples could decrease or disappear by reducing treatment in a hydrogen atmosphere at proper temperature.3.Under an applied magnetic filed of 1.8T, The two bulk samples sintered in Ar atmosphere for 12 hours at 1100℃, with the powder reduced for 30 and 60 minutes in 400℃ hydrogen atmosphere for La0.67Sr(0.20Cu0.10□0.03MnO3 parent powders, respectively, have the stable MR (11.0±0.3) % and (10.0±0.5) % in temperature range between 270K and 330K. It is important for the potential application of this kind ofmagnetoresistance material.4. Under an applied magnetic filed of 1.8T, the maximum values of MR, MRP, of the samples sintered in Ar atmosphere for 12 hours at 1100°C, with the powder reduced for 15 minutes in different temperature (2.00°C, 250°C, 300°C) hydrogen atmosphere for Lao.67Sro.2oCuo.io[Ilo.o3Mn03 parent powders, respectively, were improved comparing to one of the sample sintered with the parent sample.
The MR? of the sample sintered with parent powder is 24.6% at 319K;the MRf of the sample sintered with powder reduced for 15 minutes at 250°C, reaches 31.5%.5. On the basis of the studies about the dependence of Curie temperature of the several powder and bulk Lao.67Sr0.2oCuo.io!Ho.o3Mn03 samples on the conditions of reducing powder and sintering bulk, there are several results as follows:First, the perovskite crystal grain size and oxygen content in the lattice have a significant effect on the samples’ magnetic variation in the transition zone from ferromagnetism to paramagnetism. The effect can be described by the maximum valueofdadTUm=dadT, in which a http://www.999magnet.com represents magnetization and T representsMAXtemperature. As the crystal grain size increasing, um increases;as the oxygen content in lattice deviating from standard value 3.00,wm decreases.Second, the oxygen content in the lattice of Lao.67Sro.2oCuo.ioDo.o3Mn03 parent powder sample PI exceeds standard value 3.00. The oxygen content in the lattice of the powder sample P2, being reduced by hydrogen for 15 minutes at 200°C, approaches the standard value 3.00. Both higher reducing temperature and longer reducing time can make the oxygen content in the lattice of powder sample lower than standard value 3.00;the reducing temperature or reducing time increases, the oxygen content decreases.Third, sintering bulks in Ar atmosphere has no obvious effect on the oxygen content in samples;Sintering bulks in air atmosphere can make oxygen content in the lattice be higher than standard value 3.00, the sintering temperature or sintering time increases, the oxygen content exceeds standard value;for bulk samples sintered in air atmosphere, the lower oxygen content in the lattice of its powder is, the fewer oxygen content in the lattice of bulk samples exceed standard value 3.00, the higher magnetization the samples have.In conclusion, reducing the powder in the suitable temperature hydrogen for suitable time interval, could improve the maximum value of MR and the value of MRnear room temperature of the Lao.67Sro.20Cuo.10 D o.o3Mn03 bulk samples. The temperature stability of MR near room temperature can also be improved.
Since the 1990’s, When the colossal magnetoresistance (CMR) effect in rare-earth manganite perovskites was found, it has attracted considerable attention of scientists and engineers due to its special physics mechanism and the potential application in fields of magnetic record and magnetic sensor and so on.However, the poor temperature dependence of magnetoresistance (MR), the ideal MR occurred only in high field and the low-temperature for the most materials, severely limit their practical utilities. Many researches have thus been concentrated on making new material system that provides low field magnetoresistance (LFMR) around room temperature. On the other hand, recent efforts to broaden the CMR temperature range have been made Segment neodymium magnets by means of the Mn-site substitution or oxygen-deficiency.In this paper, La0.67Sr0.23-xCu0.10□xMnO3(x=0,0.03) polycrystalline powders were prepared by sol-gel method, which we used as parent materials. The parent powders were reduced by hydrogen in different conditions, and series of reduced powders were prepared. The bulk samples sintered in an Ar and air atmosphere respectively. Their structure, morphology, electrical and magnetic properties as well as magnetoresistance were researched in detail. There are several results we have got:1. Morphologies of La0.67Sr(0.23-x)Cu0.10□xMnO3(x=0, 0.03) parent powders and reduced powders were obtained by S-570 scanning electron microscopy (SEM). The results show that the particles in powder samples are closed to globular shape and the particle size is nanometer order. The phenomenon of conglobation in particles was improved by reducing treatment.2. The phase identification of samples has been carried out by the X-ray diffraction (XRD) with a Rigaku DMax(12KW) diffractometer. The results indicate that the Mn3O4 impurity phase in the samples could decrease or disappear by reducing treatment in a hydrogen atmosphere at proper temperature.3.Under an applied magnetic filed of 1.8T, The two bulk samples sintered in Ar atmosphere for 12 hours at 1100℃, with the powder reduced for 30 and 60 minutes in 400℃ hydrogen atmosphere for La0.67Sr(0.20Cu0.10□0.03MnO3 parent powders, respectively, have the stable MR (11.0±0.3) % and (10.0±0.5) % in temperature range between 270K and 330K. It is important for the potential application of this kind ofmagnetoresistance material.4. Under an applied magnetic filed of 1.8T, the maximum values of MR, MRP, of the samples sintered in Ar atmosphere for 12 hours at 1100°C, with the powder reduced for 15 minutes in different temperature (2.00°C, 250°C, 300°C) hydrogen atmosphere for Lao.67Sro.2oCuo.io[Ilo.o3Mn03 parent powders, respectively, were improved comparing to one of the sample sintered with the parent sample.
The MR? of the sample sintered with parent powder is 24.6% at 319K;the MRf of the sample sintered with powder reduced for 15 minutes at 250°C, reaches 31.5%.5. On the basis of the studies about the dependence of Curie temperature of the several powder and bulk Lao.67Sr0.2oCuo.io!Ho.o3Mn03 samples on the conditions of reducing powder and sintering bulk, there are several results as follows:First, the perovskite crystal grain size and oxygen content in the lattice have a significant effect on the samples’ magnetic variation in the transition zone from ferromagnetism to paramagnetism. The effect can be described by the maximum valueofdadTUm=dadT, in which a http://www.999magnet.com represents magnetization and T representsMAXtemperature. As the crystal grain size increasing, um increases;as the oxygen content in lattice deviating from standard value 3.00,wm decreases.Second, the oxygen content in the lattice of Lao.67Sro.2oCuo.ioDo.o3Mn03 parent powder sample PI exceeds standard value 3.00. The oxygen content in the lattice of the powder sample P2, being reduced by hydrogen for 15 minutes at 200°C, approaches the standard value 3.00. Both higher reducing temperature and longer reducing time can make the oxygen content in the lattice of powder sample lower than standard value 3.00;the reducing temperature or reducing time increases, the oxygen content decreases.Third, sintering bulks in Ar atmosphere has no obvious effect on the oxygen content in samples;Sintering bulks in air atmosphere can make oxygen content in the lattice be higher than standard value 3.00, the sintering temperature or sintering time increases, the oxygen content exceeds standard value;for bulk samples sintered in air atmosphere, the lower oxygen content in the lattice of its powder is, the fewer oxygen content in the lattice of bulk samples exceed standard value 3.00, the higher magnetization the samples have.In conclusion, reducing the powder in the suitable temperature hydrogen for suitable time interval, could improve the maximum value of MR and the value of MRnear room temperature of the Lao.67Sro.20Cuo.10 D o.o3Mn03 bulk samples. The temperature stability of MR near room temperature can also be improved.
2012年8月20日星期一
Design of MW Grade Direct-Driven Permanent-Magnet Synchronous Generators for Wind Turbines
Design of MW Grade Direct-Driven Permanent-Magnet Synchronous Generators for Wind Turbines
Without the typical gearbox in wind-generating system and the disadvantages caused by gearbox, the PMSG (permanent magnetic Synchronous generator) is directly driven by the wind turbine at low speed, which makes the operation of the generator more Segment neodymium magnet liable. PMSG is different with salient pole Synchronous generator and its poles are made of the rare earth material with high BH product, which avoids the excitation losses, makes the generator structure simpler with high efficiency.Direct-driven PMSG works at low speed and its size is generally big. In this paper, the inner-rotor structure is selected for the convenient transportation and good cooling. Firstly the design goal is proposed and it is to improve the generator liability and lower http://www.chinamagnets.biz the cost on the precondition that match with the basic generator parameter requirements. Then a program is developed on the theory of EMCM (equivalent magnetic circuit method) and it is used in the pre-design of the PMSG. Thirdly generator characterizes are analyzed on different working condition with FEA (finite element analyze). Finally, the air-cooling system is designed and air rate is calculated.
Without the typical gearbox in wind-generating system and the disadvantages caused by gearbox, the PMSG (permanent magnetic Synchronous generator) is directly driven by the wind turbine at low speed, which makes the operation of the generator more Segment neodymium magnet liable. PMSG is different with salient pole Synchronous generator and its poles are made of the rare earth material with high BH product, which avoids the excitation losses, makes the generator structure simpler with high efficiency.Direct-driven PMSG works at low speed and its size is generally big. In this paper, the inner-rotor structure is selected for the convenient transportation and good cooling. Firstly the design goal is proposed and it is to improve the generator liability and lower http://www.chinamagnets.biz the cost on the precondition that match with the basic generator parameter requirements. Then a program is developed on the theory of EMCM (equivalent magnetic circuit method) and it is used in the pre-design of the PMSG. Thirdly generator characterizes are analyzed on different working condition with FEA (finite element analyze). Finally, the air-cooling system is designed and air rate is calculated.
Robust Velocity Control System of Linear Permanent Synchronous Motor
Robust Velocity Control System of Linear Permanent Synchronous Motor
Along with power electronics, micro-processor, micro-electronics, rare earth permanent magnetic materials and modern control theory, permanent magnetic synchronous motor (PMSM) has been widely in motion control of medium and low capacity both in industry and daily living. Besides, it seems to expect trend its taking place of DC motor and asynchronous Ring neodymium magnet motor for velocity control gradually. Meanwhile, conventional lathe has intermediate conversion segments transporting rotating motor into linear motor, which confine precision. Linear permanent magnetic synchronous motor (LPMSM) has ability to move linearly without intermediate conversion segments and conquers the inherent defect.In this paper, the research object is the velocity controller of the linear permanent magnetic motor. First design considerations and work principle are introduced, http://www.chinamagnets.biz and motion equations are listed. Then, space vector modulation is presented and robust velocity controller is designed based on theory of robusticity. After that, the system is simulated on the platform of MATLAB. Finally, hardware based on DSP TMS240LF2407 and software are designed, and some experiment are complete.
Along with power electronics, micro-processor, micro-electronics, rare earth permanent magnetic materials and modern control theory, permanent magnetic synchronous motor (PMSM) has been widely in motion control of medium and low capacity both in industry and daily living. Besides, it seems to expect trend its taking place of DC motor and asynchronous Ring neodymium magnet motor for velocity control gradually. Meanwhile, conventional lathe has intermediate conversion segments transporting rotating motor into linear motor, which confine precision. Linear permanent magnetic synchronous motor (LPMSM) has ability to move linearly without intermediate conversion segments and conquers the inherent defect.In this paper, the research object is the velocity controller of the linear permanent magnetic motor. First design considerations and work principle are introduced, http://www.chinamagnets.biz and motion equations are listed. Then, space vector modulation is presented and robust velocity controller is designed based on theory of robusticity. After that, the system is simulated on the platform of MATLAB. Finally, hardware based on DSP TMS240LF2407 and software are designed, and some experiment are complete.
The Design of Power Source of Linear Motor Based on Bilateral Pulse Variable Frequency Control
The Design of Power Source of Linear Motor Based on Bilateral Pulse Variable Frequency Control
For decreasing a mass of wastage of traditional rotating motor which is used to be linear driving equipment by shift rotary movement to linear movement via middle switch component, linear motor emerged as the times require. Traditional linear motor adopted spring to reset, whereas in this paper the structure and drive mode of linear motor are innovated, which secondary adopts rare-earth permanent-magnet material, driving with non-contact electromagnetic gear by Cube neodymium magnet altering the polarty of power supple to realize the reciprocating motion.Linear motor consists of two main parts which are motor and power supply. this subject mainly introduces the structure of motor and design of working power supply, for achieving the movement fully driven by magnetic force, power supply is designed to drive by bidirectional pulse, and PFC correcting circuit is to maintain high power factor to reduce the harmonic wave pollution to power grid.
Thereinto PFC correcting circuit is to correct the phase angle of voltage and current with One-cycle control Boost circuit, as well as the converter model is constructed under DCM condition according to switched linear theory. The controllability and reachability are also analyzed hereinafter, likewise the analytical methods could be used in the analysis of http://www.chinamagnets.biz Buck and Buck-Boost converter. Bidirectional pulse driving circuit controlled by SCM driving IGBT bridge circuit which chip model No. FGA25N120 as core component to design the power supply, to achieve frequency control by controlling impulse width and cycle with build-in keyboard, in the meantime over-voltage protection and over-current protection are taken into account.Now the novel linear motor of bidirectional pulse variable-frequency control is applied to drive the flow control pump successfully.The new-style structure has applied for practical novel patent. This subject been supported by the project of young talents training of Changzhou and project of tackle scientific problem of new north district of Changzhou.
For decreasing a mass of wastage of traditional rotating motor which is used to be linear driving equipment by shift rotary movement to linear movement via middle switch component, linear motor emerged as the times require. Traditional linear motor adopted spring to reset, whereas in this paper the structure and drive mode of linear motor are innovated, which secondary adopts rare-earth permanent-magnet material, driving with non-contact electromagnetic gear by Cube neodymium magnet altering the polarty of power supple to realize the reciprocating motion.Linear motor consists of two main parts which are motor and power supply. this subject mainly introduces the structure of motor and design of working power supply, for achieving the movement fully driven by magnetic force, power supply is designed to drive by bidirectional pulse, and PFC correcting circuit is to maintain high power factor to reduce the harmonic wave pollution to power grid.
Thereinto PFC correcting circuit is to correct the phase angle of voltage and current with One-cycle control Boost circuit, as well as the converter model is constructed under DCM condition according to switched linear theory. The controllability and reachability are also analyzed hereinafter, likewise the analytical methods could be used in the analysis of http://www.chinamagnets.biz Buck and Buck-Boost converter. Bidirectional pulse driving circuit controlled by SCM driving IGBT bridge circuit which chip model No. FGA25N120 as core component to design the power supply, to achieve frequency control by controlling impulse width and cycle with build-in keyboard, in the meantime over-voltage protection and over-current protection are taken into account.Now the novel linear motor of bidirectional pulse variable-frequency control is applied to drive the flow control pump successfully.The new-style structure has applied for practical novel patent. This subject been supported by the project of young talents training of Changzhou and project of tackle scientific problem of new north district of Changzhou.
Preparation and Characterization of Doped Zinc Oxide(ZnO) Thin Films
Preparation and Characterization of Doped Zinc Oxide(ZnO) Thin Films
ZnO is a wide band gap semiconductor with optical transparency in the visible range. It crystallizes is a hexagonal wurtzite structure with 3.30 eV band gap and large exciton binding energy of 60meV at room temperature. ZnO is a kind of very promising materials for making the optoelectronics devices such as UV/blue light-emitting diodes and short-wavelength semiconductor diode laser devices and put in application. In recent years, the fabrication of ZnO Block neodymium magnet films has attracted a considerable amount of interest due to their potential application in flat-paned displays, solar cells, gas sensors and optical waveguides.In this thesis, transparent and conductive high-preferential c-axis-oriented zinc oxide (ZnO) thin films have been prepared by sol-gel method. Zinc oxide thin films with varying thickness and different annealed temperature were fabricated and discussed in detail. The SEM micrographs and XRD patterns of the ZnO films showed that the film had a smooth surface and strongest orientation.
The films have very strong absorption in the short wavelength range and the absorption edge is about 370nm.The optical transmittance spectra of the film showed a good transmittance (85%) within the visible wavelength region.Al-doped Zinc Oxide thin films were prepared by sol-gel mathod, The optical and electrical characteristics of the ZAO thin films were http://www.chinamagnets.biz investigated.The results showed that: (l)The X-ray diffraction patterns show that ZAO thin films has ahexagonal wurtzite structure. (2)Photoluminescence (PL) spectra of the ZAO thin films have blue shift. (3) Raman spectrum of the ZAO thin films had changed with different Al-doped ratio. (4)The maximum conductance of 1.3×103S/cm was obtained for the thin films doped with 1% Al3+, annealed at 700 ℃.Effects of Ag、Ce and Ti doping on the microstructures and optical properties of ZnO thin film were studied. The results showed that thim film has ahexagonal wurtzite structure and transmittance of thin film had changed within 400nm600nm.
ZnO is a wide band gap semiconductor with optical transparency in the visible range. It crystallizes is a hexagonal wurtzite structure with 3.30 eV band gap and large exciton binding energy of 60meV at room temperature. ZnO is a kind of very promising materials for making the optoelectronics devices such as UV/blue light-emitting diodes and short-wavelength semiconductor diode laser devices and put in application. In recent years, the fabrication of ZnO Block neodymium magnet films has attracted a considerable amount of interest due to their potential application in flat-paned displays, solar cells, gas sensors and optical waveguides.In this thesis, transparent and conductive high-preferential c-axis-oriented zinc oxide (ZnO) thin films have been prepared by sol-gel method. Zinc oxide thin films with varying thickness and different annealed temperature were fabricated and discussed in detail. The SEM micrographs and XRD patterns of the ZnO films showed that the film had a smooth surface and strongest orientation.
The films have very strong absorption in the short wavelength range and the absorption edge is about 370nm.The optical transmittance spectra of the film showed a good transmittance (85%) within the visible wavelength region.Al-doped Zinc Oxide thin films were prepared by sol-gel mathod, The optical and electrical characteristics of the ZAO thin films were http://www.chinamagnets.biz investigated.The results showed that: (l)The X-ray diffraction patterns show that ZAO thin films has ahexagonal wurtzite structure. (2)Photoluminescence (PL) spectra of the ZAO thin films have blue shift. (3) Raman spectrum of the ZAO thin films had changed with different Al-doped ratio. (4)The maximum conductance of 1.3×103S/cm was obtained for the thin films doped with 1% Al3+, annealed at 700 ℃.Effects of Ag、Ce and Ti doping on the microstructures and optical properties of ZnO thin film were studied. The results showed that thim film has ahexagonal wurtzite structure and transmittance of thin film had changed within 400nm600nm.
Study on High Strength Cast Aluminum Alloy Applied to High-speed Train
Study on High Strength Cast Aluminum Alloy Applied to High-speed Train
High-speed train is the developing trend of railway transportation in china, of which weight reduction is one of the key techniques of High-speed train. Nowadays in our country, most materials used in the parts of trains are made of iron and steel, which make the train have high weight, and limit the development of high-speed train. Therefore, it is of great theoretical and Ball Neodymium Magnets practical significance to explore new lighter material to take the place of current steel material.Aluminum alloy is the optimum material for weight reduction. However, the properties of presently existing cast aluminum alloys can not meet the requirements of the key parts of High-speed train. And their casting technique is easy to make more foundry defects. A new cast aluminum alloy is developed in this paper. Mg and Zn are the main elements of the alloy. Preparation technique and heat treatment technology are also investigated. The result shows that the tensile strength is 400 MPa and the http://www.chinamagnets.biz elongation is 10.1%; the alloy has better pourability than Al-Cu series alloy and has slight thermal cracking tendency; second-class heat treatment is adopted ,which makes the best solution strength; the phase of T(Al2 Mg3 Zn3)exists at the grain boundary in the reticular form as cast, while after being heat treated most of it dissolve in the basal body; element Mn change needle-like Al3Fe into stick-like state, and the addition of rare earth elements better its shape further; to improve the density of cast is one of good strengthening methods of aluminum alloy, with which the strength of ZL101 is improved by 51% as cast; porosity can also be used to check the feeding passage blocked or not.
High-speed train is the developing trend of railway transportation in china, of which weight reduction is one of the key techniques of High-speed train. Nowadays in our country, most materials used in the parts of trains are made of iron and steel, which make the train have high weight, and limit the development of high-speed train. Therefore, it is of great theoretical and Ball Neodymium Magnets practical significance to explore new lighter material to take the place of current steel material.Aluminum alloy is the optimum material for weight reduction. However, the properties of presently existing cast aluminum alloys can not meet the requirements of the key parts of High-speed train. And their casting technique is easy to make more foundry defects. A new cast aluminum alloy is developed in this paper. Mg and Zn are the main elements of the alloy. Preparation technique and heat treatment technology are also investigated. The result shows that the tensile strength is 400 MPa and the http://www.chinamagnets.biz elongation is 10.1%; the alloy has better pourability than Al-Cu series alloy and has slight thermal cracking tendency; second-class heat treatment is adopted ,which makes the best solution strength; the phase of T(Al2 Mg3 Zn3)exists at the grain boundary in the reticular form as cast, while after being heat treated most of it dissolve in the basal body; element Mn change needle-like Al3Fe into stick-like state, and the addition of rare earth elements better its shape further; to improve the density of cast is one of good strengthening methods of aluminum alloy, with which the strength of ZL101 is improved by 51% as cast; porosity can also be used to check the feeding passage blocked or not.
Investigation on Effects of Different Additions on Microstructures and Properties of Cu-W Alloys
Investigation on Effects of Different Additions on Microstructures and Properties of Cu-W Alloys
Cu-W alloy is widely used as electrical contact material in various high voltage interrupters and as electrode material for electrical discharge machining, due to its advantages of high strength, excellent resistance to arc erosion and to welding. By means of powder metallurgy-infiltration, a series of Cu-W alloys added respectively with carbides and neodymium magnets rare earth oxides were prepared in this paper. The effects of different additions with different content on microstructures and properties including the static property and the vacuum breakdown property of Cu-W alloys were investigated respectively. The results showed:1. In the range of 0%-1.5% (wt %) WC addition, the hardness of Cu-W alloys showed increase with increasing percentage of WC, while electric conductivity changed slightly. Distinct decreases were observed from 1.5% to 3.0% WC addition.2. For Cu-W alloys with 0～2%TiC (wt %) additions, while TiC content less than 1.2%, the hardness of alloys showed increase with increasing percentage of TiC, the electric conductivity changed slightly. While the weight fraction of TiC reached 1.2%, Cu-W alloy achieves the best overall property. The hardness and electric conductivity of alloys with higher content of TiC addition were decreased dramatically.3. In the range of 0%-0.5% (wt %) CeO2 addition, the hardness of Cu-W alloys showed increase with increasing percentage of CeO2, however, the electric conductivity changed slightly. Distinct decreases were http://www.chinamagnets.biz observed from 0.5% to 1.5% CeO2 addition.4. For Cu-W alloys with 0～1.2%Y2O3 (wt %) additions, while Y2O3 content less than 0.4%, the hardness of alloys showed increase with increasing percentage of Y2O3, the electric conductivity changed slightly. While the weight fraction of Y2O3 reached 1.2%, Cu-W alloy achieved the best overall property. The hardness and electric conductivity of alloys with more than 1.2% Y2O3 addition are decreased dramatically.5. In the four kinds of Cu-W alloys with suitable content of WC, TiC, CeO2. Y2O3 added respectively, the size of the tungsten particles decreased because these dispersion-strengthened
Cu-W alloy is widely used as electrical contact material in various high voltage interrupters and as electrode material for electrical discharge machining, due to its advantages of high strength, excellent resistance to arc erosion and to welding. By means of powder metallurgy-infiltration, a series of Cu-W alloys added respectively with carbides and neodymium magnets rare earth oxides were prepared in this paper. The effects of different additions with different content on microstructures and properties including the static property and the vacuum breakdown property of Cu-W alloys were investigated respectively. The results showed:1. In the range of 0%-1.5% (wt %) WC addition, the hardness of Cu-W alloys showed increase with increasing percentage of WC, while electric conductivity changed slightly. Distinct decreases were observed from 1.5% to 3.0% WC addition.2. For Cu-W alloys with 0～2%TiC (wt %) additions, while TiC content less than 1.2%, the hardness of alloys showed increase with increasing percentage of TiC, the electric conductivity changed slightly. While the weight fraction of TiC reached 1.2%, Cu-W alloy achieves the best overall property. The hardness and electric conductivity of alloys with higher content of TiC addition were decreased dramatically.3. In the range of 0%-0.5% (wt %) CeO2 addition, the hardness of Cu-W alloys showed increase with increasing percentage of CeO2, however, the electric conductivity changed slightly. Distinct decreases were http://www.chinamagnets.biz observed from 0.5% to 1.5% CeO2 addition.4. For Cu-W alloys with 0～1.2%Y2O3 (wt %) additions, while Y2O3 content less than 0.4%, the hardness of alloys showed increase with increasing percentage of Y2O3, the electric conductivity changed slightly. While the weight fraction of Y2O3 reached 1.2%, Cu-W alloy achieved the best overall property. The hardness and electric conductivity of alloys with more than 1.2% Y2O3 addition are decreased dramatically.5. In the four kinds of Cu-W alloys with suitable content of WC, TiC, CeO2. Y2O3 added respectively, the size of the tungsten particles decreased because these dispersion-strengthened
2012年8月15日星期三
Research on the Steering Engine Controller in Missile Based on Fractal Modified PID Algorithm
Research on the Steering Engine Controller in Missile Based on Fractal Modified PID Algorithm
Aiming at the steering gear machinery in some missiles,adopting the combined configuration of small rare earth torque motor and harmonic drive reducer, a combined control strategy is designed. Considering the change with velocity and small damp of harmonic drive, adopting the complement between linear model and fractal model, The increasing Special shape NdFeB magnets PID (Proportional–Integral–Derivative)control system based on the rate character of fractal geometry is its exact section.In the aspect of hardware system, two design steps are constituted. In the first period, the control system based on the structure of CPU+FPGA with USB2.0 has been designed to get the specialty of this system and obtain the suitable algorithm. Based on the anterior experience, in the second period, the DSP control system with CAN2.0 has been designed, which is more integrated and http://www.999magnet.com more dependable. The testing result indicates that this control system has the merits such as good capability of anti-jamming, excellent control quality, and so on.At the end of the paper, all factors that affect system performance are analyzed, and optimization designs are presented.
Aiming at the steering gear machinery in some missiles,adopting the combined configuration of small rare earth torque motor and harmonic drive reducer, a combined control strategy is designed. Considering the change with velocity and small damp of harmonic drive, adopting the complement between linear model and fractal model, The increasing Special shape NdFeB magnets PID (Proportional–Integral–Derivative)control system based on the rate character of fractal geometry is its exact section.In the aspect of hardware system, two design steps are constituted. In the first period, the control system based on the structure of CPU+FPGA with USB2.0 has been designed to get the specialty of this system and obtain the suitable algorithm. Based on the anterior experience, in the second period, the DSP control system with CAN2.0 has been designed, which is more integrated and http://www.999magnet.com more dependable. The testing result indicates that this control system has the merits such as good capability of anti-jamming, excellent control quality, and so on.At the end of the paper, all factors that affect system performance are analyzed, and optimization designs are presented.
Study on Tunable Fiber Lasers Suitable for ITU Standard DWDM Optical Communication Systems
Study on Tunable Fiber Lasers Suitable for ITU Standard DWDM Optical Communication Systems
DWDM has been an economical and effective approach of the capacity extending and upgrading of optical communication system. As the critical components for optical communication, Fiber Bragg Grating and fiber lasers are widely used in DWDM networks. In this dissertation, we study theory and experiment of fiber lasers with FBG. Theory and methods of wavelength tuning with FBG is also present.Keep to these points, several work is carried out as follows:1. In the second chapter, the framework and theory of fiber laser are present, then the thesis explains the Special shape NdFeB magnets structure of the Er3+, introduce the working principle of fiber laser. Besides, tunable laser is also present in this thesis, including the tunable semiconductor laser, the tunable fiber laser and their sorts and the research situation of every different sort.2. In the third chapter, the thesis starts with the research situation of fiber grating, then after introducing the category, the thesis presents the theoretical analysis of the temperature and stress influence on the FBG’s bragg wavelength. At last some methods for wavelength tuning are present and compared.3. In the fourth thesis, the output characteristics are studied theoretically, the best fiber length and the connection between the threshold power and the fiber length are gained. Then we proposed a series of experiment schemes. Er3+ doped fiber ring and line lasers, which are pumped http://www.999magnet.com by a laser of 980nm, are realized. Emissing wavelengths are 1538.1nm and 1536.5nm, the output power of 0.76mV, 0.83mV, 0.92mV, 0.94mV are respective achieved. And we also made experiments on tunable and multiwavelength fiber lasers.To sum up,theoretical studies, methods comparing and experiment test of fiber laser with FBG are discussed, and some data is obtained which is useful for the future research.
DWDM has been an economical and effective approach of the capacity extending and upgrading of optical communication system. As the critical components for optical communication, Fiber Bragg Grating and fiber lasers are widely used in DWDM networks. In this dissertation, we study theory and experiment of fiber lasers with FBG. Theory and methods of wavelength tuning with FBG is also present.Keep to these points, several work is carried out as follows:1. In the second chapter, the framework and theory of fiber laser are present, then the thesis explains the Special shape NdFeB magnets structure of the Er3+, introduce the working principle of fiber laser. Besides, tunable laser is also present in this thesis, including the tunable semiconductor laser, the tunable fiber laser and their sorts and the research situation of every different sort.2. In the third chapter, the thesis starts with the research situation of fiber grating, then after introducing the category, the thesis presents the theoretical analysis of the temperature and stress influence on the FBG’s bragg wavelength. At last some methods for wavelength tuning are present and compared.3. In the fourth thesis, the output characteristics are studied theoretically, the best fiber length and the connection between the threshold power and the fiber length are gained. Then we proposed a series of experiment schemes. Er3+ doped fiber ring and line lasers, which are pumped http://www.999magnet.com by a laser of 980nm, are realized. Emissing wavelengths are 1538.1nm and 1536.5nm, the output power of 0.76mV, 0.83mV, 0.92mV, 0.94mV are respective achieved. And we also made experiments on tunable and multiwavelength fiber lasers.To sum up,theoretical studies, methods comparing and experiment test of fiber laser with FBG are discussed, and some data is obtained which is useful for the future research.
2012年8月13日星期一
电沉积纳米复合镀层的工艺及性能研究
电沉积纳米复合镀层的工艺及性能研究
A series new Ni-W P-SiO2, RE-Ni-W-P, RE-Ni-W-P-SiO2 nano-composite coatings with more excellent corrosion-resistance, hardness, oxidation-resistance and wear-resistance by direct current were studied. The deposited composition, the properties and structure were tested by EPMA-1600 electron probe, 3015 X-ray diffraction patterns, optics microscope, HX-1 micro-hardness instrument, HDV-7 transistor permanent potential apparatus, marinating in acid ,etc.The potential-PH diagram of Ni-P-H2O system at 298K. was constructed by use of thermodynamic data. The formation mechanism of Ni-W P-SiO2 system composite coatings was explained by means of potential-PH diagram, and the feasibility of nano-composite plating was analyzed by the Block Neodymium magnets mechanism and influence factors of direct plating. According to study effects that different technics conditions affect on nano-composite coatings in corrosion-resistance, hardness, oxidation-resistance , we can get the best technics conditions as follows: in the plating solution, the concentration of CeO2 is 6g/L, the concentration of SiO2 is 70g/L; PH=5; T=40℃; Dk=10A/dm2The corrosion-resistance, hardness, oxidation-resistance of RE-Ni-W, RE-Ni-W-P, Ni-W-P-SiO2, RE-Ni-W-P-SiO2 nano-composite coatings were studied in this article. The result of study is as follows :Whether ordinary composite plating coatings or the heat-treatment one at 400 ℃ , the hardness of nano-composite coatings are higher than the hardness of micron composite coatings, and the former one is better than the latter one in combine force. The nano-particulates are equably separated in the nano-composite coatings and it make the crystalloid fine http://www.999magnet.com for nano-particulate have a small size . especially joining in nano-CeO2 can make nano-composite coatings have more superiority capability than micron composite coatings.The order of hardness of nano-composite coatings from high to low is that Ni-W-P-SiO2>RE-Ni-W-P-SiO2>RE-Ni-W-P. According to study and contrast the
A series new Ni-W P-SiO2, RE-Ni-W-P, RE-Ni-W-P-SiO2 nano-composite coatings with more excellent corrosion-resistance, hardness, oxidation-resistance and wear-resistance by direct current were studied. The deposited composition, the properties and structure were tested by EPMA-1600 electron probe, 3015 X-ray diffraction patterns, optics microscope, HX-1 micro-hardness instrument, HDV-7 transistor permanent potential apparatus, marinating in acid ,etc.The potential-PH diagram of Ni-P-H2O system at 298K. was constructed by use of thermodynamic data. The formation mechanism of Ni-W P-SiO2 system composite coatings was explained by means of potential-PH diagram, and the feasibility of nano-composite plating was analyzed by the Block Neodymium magnets mechanism and influence factors of direct plating. According to study effects that different technics conditions affect on nano-composite coatings in corrosion-resistance, hardness, oxidation-resistance , we can get the best technics conditions as follows: in the plating solution, the concentration of CeO2 is 6g/L, the concentration of SiO2 is 70g/L; PH=5; T=40℃; Dk=10A/dm2The corrosion-resistance, hardness, oxidation-resistance of RE-Ni-W, RE-Ni-W-P, Ni-W-P-SiO2, RE-Ni-W-P-SiO2 nano-composite coatings were studied in this article. The result of study is as follows :Whether ordinary composite plating coatings or the heat-treatment one at 400 ℃ , the hardness of nano-composite coatings are higher than the hardness of micron composite coatings, and the former one is better than the latter one in combine force. The nano-particulates are equably separated in the nano-composite coatings and it make the crystalloid fine http://www.999magnet.com for nano-particulate have a small size . especially joining in nano-CeO2 can make nano-composite coatings have more superiority capability than micron composite coatings.The order of hardness of nano-composite coatings from high to low is that Ni-W-P-SiO2>RE-Ni-W-P-SiO2>RE-Ni-W-P. According to study and contrast the
韩国的传统色彩
韩国的传统色彩
The five orthodox colours here are yellow, cyan, white, crimson and black, which are based on the theory of yin-yang and five elements. The yin and yang shape the heaven and earth and then evolve into the five elements: metal, wood, water, fire and earth.The five elements correspond to five colours involving with certain geographical directions. Taking the center and other four directions as the pivot, yellow is corresponding to the center, cyan to the east, white to the west, crimson to the south and black to the north.In addition, the intermediate colour of cyan and yellow is green, cyan and white is azure green, crimson and white is red, black and crimson is purple, and black and yellow is brimstone. They are called five intermediate colours or five mixture colours.Segment neodymium magnets Yellow is corresponding to the "earth" element in five elements, which is considered to represent the center of the universe and is very privileged. So it was always selected as the colour of the emperors’ clothes. Cyan is corresponding to the wood, the colour related to vibrant spring and is considered to be able to repel the devil and bring good fortune. White is corresponding to the metal, indicating the birth, creation, enthusiasm, love and enthusiasm. So it is strongly correlative to something talismanic.
Black is corresponding to the water, an element representing the wisdom of human being.So based on the thought of yin-yang and five elements, these five colours turn out to be closely related to our daily life. Brides rouge when they get married to repel the ghost; children wear rainbow-coloured clothes on the hundredth day since their birth and in various festivals to repel the devil and to bless health and long life; The mouth of crock brewing soy is surrounded by a http://www.999magnet.com string of chili called "forbidden line" ; noodle in the wedding ceremony is sprinkled with five-coloured decorates, Build houses by loess glimmering red or paste red charm on Spring festival; The painting in the palaces and temples; the fresco in the Goguryeo’s ancient tomb of Koguryo dynasty and the handicrafts such as patchworks are good examples all the above are good examples making use of the five colours’principle.
The five orthodox colours here are yellow, cyan, white, crimson and black, which are based on the theory of yin-yang and five elements. The yin and yang shape the heaven and earth and then evolve into the five elements: metal, wood, water, fire and earth.The five elements correspond to five colours involving with certain geographical directions. Taking the center and other four directions as the pivot, yellow is corresponding to the center, cyan to the east, white to the west, crimson to the south and black to the north.In addition, the intermediate colour of cyan and yellow is green, cyan and white is azure green, crimson and white is red, black and crimson is purple, and black and yellow is brimstone. They are called five intermediate colours or five mixture colours.Segment neodymium magnets Yellow is corresponding to the "earth" element in five elements, which is considered to represent the center of the universe and is very privileged. So it was always selected as the colour of the emperors’ clothes. Cyan is corresponding to the wood, the colour related to vibrant spring and is considered to be able to repel the devil and bring good fortune. White is corresponding to the metal, indicating the birth, creation, enthusiasm, love and enthusiasm. So it is strongly correlative to something talismanic.
Black is corresponding to the water, an element representing the wisdom of human being.So based on the thought of yin-yang and five elements, these five colours turn out to be closely related to our daily life. Brides rouge when they get married to repel the ghost; children wear rainbow-coloured clothes on the hundredth day since their birth and in various festivals to repel the devil and to bless health and long life; The mouth of crock brewing soy is surrounded by a http://www.999magnet.com string of chili called "forbidden line" ; noodle in the wedding ceremony is sprinkled with five-coloured decorates, Build houses by loess glimmering red or paste red charm on Spring festival; The painting in the palaces and temples; the fresco in the Goguryeo’s ancient tomb of Koguryo dynasty and the handicrafts such as patchworks are good examples all the above are good examples making use of the five colours’principle.
Experimental Investigations on the Emissions Durability of Motorcycles with EFI
Experimental Investigations on the Emissions Durability of Motorcycles with EFI
Energy and the environment are the two main themes of social in the 21st century. The production of motorcycles has exceeded 25 million per year, which accounts for more than half of the world output. Therefore, in order to reduce emissions and meet increasingly stringent emissions regulations, the motorcycle scientific researchers should seek actively measures to reduce emissions. And then the motorcycle industry will scale new heights.To meet the 3rd emissions regulations of our country, researches on the following aspects in this article:1. Optimized the hardware Alnico magnets of the engine electronic control system successfully. Designed and developed the throttle body and the pump components. Designed the driver circuit of the idle bypass valve and the carbon monoxide tank.2.
Designed the control strategy of the idle bypass valve which meet the request of the engine idle and warming states. Established the different air-fuel ratio control strategies based on the different conditions of engine.3. Based on the CAN, designed and developed the integrated calibration which achieves four main functions: real-time parameters acquisition and display, on-line parameters editing, data saving and data playback .4. Calibration experimental investigation has been completed on a 125 ml single-cylinder four-stroke spark ignition engine. Researches on the flow characteristics and the dynamic response performence of the fuel injector were achived. It provided a prerequisite to the precise control of the air-fuel ratio. Determined the installation positions of TWC and oxygen sensor by measuring exhaust temperatures of the engine.5. A large number of studies on the vehicle calibration and emissions durability testing were finished. Put focus on the two factors impacting emissions durability. http://www.999magnet.com One is the drift issues of oxygen sensor, we developed and designed the self-learning control strategy of oxygen sensor; the other one is the problem of the three-way catalyst aging. The use of rare earth with high-performance oxygen storage materials and high temperature and high surface area, which reduced greatly the cost, increased the activity of a catalyst, extended the service life and achieved the emission durability test. Reached the third emission standards of our country .6.After 12000 km emissions durability assessment of the improved motorcycle with EFI, emission test results showed that HC emissions accounted for only about 40%, CO emissions accounted for only about 50 percent, and NOx emissions accounted for 78.7 percent of the emission standards,The results meet emission limits and motorcycle measurement method (GB14622-2007) requirements.
Energy and the environment are the two main themes of social in the 21st century. The production of motorcycles has exceeded 25 million per year, which accounts for more than half of the world output. Therefore, in order to reduce emissions and meet increasingly stringent emissions regulations, the motorcycle scientific researchers should seek actively measures to reduce emissions. And then the motorcycle industry will scale new heights.To meet the 3rd emissions regulations of our country, researches on the following aspects in this article:1. Optimized the hardware Alnico magnets of the engine electronic control system successfully. Designed and developed the throttle body and the pump components. Designed the driver circuit of the idle bypass valve and the carbon monoxide tank.2.
Designed the control strategy of the idle bypass valve which meet the request of the engine idle and warming states. Established the different air-fuel ratio control strategies based on the different conditions of engine.3. Based on the CAN, designed and developed the integrated calibration which achieves four main functions: real-time parameters acquisition and display, on-line parameters editing, data saving and data playback .4. Calibration experimental investigation has been completed on a 125 ml single-cylinder four-stroke spark ignition engine. Researches on the flow characteristics and the dynamic response performence of the fuel injector were achived. It provided a prerequisite to the precise control of the air-fuel ratio. Determined the installation positions of TWC and oxygen sensor by measuring exhaust temperatures of the engine.5. A large number of studies on the vehicle calibration and emissions durability testing were finished. Put focus on the two factors impacting emissions durability. http://www.999magnet.com One is the drift issues of oxygen sensor, we developed and designed the self-learning control strategy of oxygen sensor; the other one is the problem of the three-way catalyst aging. The use of rare earth with high-performance oxygen storage materials and high temperature and high surface area, which reduced greatly the cost, increased the activity of a catalyst, extended the service life and achieved the emission durability test. Reached the third emission standards of our country .6.After 12000 km emissions durability assessment of the improved motorcycle with EFI, emission test results showed that HC emissions accounted for only about 40%, CO emissions accounted for only about 50 percent, and NOx emissions accounted for 78.7 percent of the emission standards,The results meet emission limits and motorcycle measurement method (GB14622-2007) requirements.
2012年8月12日星期日
Discussion on Forming Conditions and Process of the Barite-Witherite Deposits in Lower Cambrian, Northern Daba Mountains, China
Discussion on Forming Conditions and Process of the Barite-Witherite Deposits in Lower Cambrian, Northern Daba Mountains, China
Many stratiform witherite deposits, located in the black rock series of Lower Cambrian on the border land of Shaanxi, Sichuan, Chongqing and Hubei provinces, make up a unique large barium mineralization belt of the world with stratiform barite deposits. Some of them are of superlarge scale. Most of the witherite deposits are hosted in the carbonaceous siliceous rocks of Lujiaping Formation with obvious sedimentary characteristics observed macroscopically. In order to provide scientific foundation for mineral predication and promote the rational exploitation and Magnetic lifter utilization of the ore belt, the paper analyzed the ore-forming conditions and processes of the barite-witherite deposits such as Huangbaishuwan, Miaozi, Bashan, and Wenyuhe.Data of major elements, trace elements, REEs and relative isotopes suggest that these deposits formed in the epicontinental hydrothermal environment. The accurate places were in a sag on the outer shelf probably. Semi-closed backwater had an important impact on the forming of deposits. Some data on organic geochemical indicate that the organic matters with high productivity are of sapropelic type.
They derived from bacteria and algae in the sea and evolved into the phase of high maturation. Including CH4, a great deal of hydrocarbons were pyrolyzed out.Strontium isotopic values of the ores show that barium was derived from the mantle. δ13Cpdb values of witherite are abnormal negatively, reflecting the participation of organic carbon. Values of sulfur isotopes suggest that seawater had provided sulfur for the formation of barite. Data of hydrogen and oxygen isotopes show that organic water was included in the ore-forming fluid.Hydrothermal water accelerated the migration and precipitation of barium, affected the characteristics of the ore-forming fluids as well as http://www.999magnet.com the redox conditions of the environment. Different types of paleo-hydrothermal water determined the diversities of these barite-witherite deposits. There was carbonate hydrothermal water field near the Daba Mountain Arc Fault. Plentiful anions of CO32- got together in the backwater environment. At Wenyuhe and its neighborhood sulfate hydrothermal water fields have been detected. The upward removal of hydrocarbons (including CH4) had a great impact on the forming of witherite.Factors that led to the paragenesia and separation of witherite and barite included the differences of their solubilities, chemical coprecipitation of several kinds of minerals and the redox reaction between CH4 and SO42- in the hydrothermal background. Under the circumstances of tectonic movement in the later, stratigraphic overturning led to the changing of orebody occurrences and the appearance of several alternations. Meanwhile the components, textures, structures and other aspects of the consolidated rocks were also changed.
Many stratiform witherite deposits, located in the black rock series of Lower Cambrian on the border land of Shaanxi, Sichuan, Chongqing and Hubei provinces, make up a unique large barium mineralization belt of the world with stratiform barite deposits. Some of them are of superlarge scale. Most of the witherite deposits are hosted in the carbonaceous siliceous rocks of Lujiaping Formation with obvious sedimentary characteristics observed macroscopically. In order to provide scientific foundation for mineral predication and promote the rational exploitation and Magnetic lifter utilization of the ore belt, the paper analyzed the ore-forming conditions and processes of the barite-witherite deposits such as Huangbaishuwan, Miaozi, Bashan, and Wenyuhe.Data of major elements, trace elements, REEs and relative isotopes suggest that these deposits formed in the epicontinental hydrothermal environment. The accurate places were in a sag on the outer shelf probably. Semi-closed backwater had an important impact on the forming of deposits. Some data on organic geochemical indicate that the organic matters with high productivity are of sapropelic type.
They derived from bacteria and algae in the sea and evolved into the phase of high maturation. Including CH4, a great deal of hydrocarbons were pyrolyzed out.Strontium isotopic values of the ores show that barium was derived from the mantle. δ13Cpdb values of witherite are abnormal negatively, reflecting the participation of organic carbon. Values of sulfur isotopes suggest that seawater had provided sulfur for the formation of barite. Data of hydrogen and oxygen isotopes show that organic water was included in the ore-forming fluid.Hydrothermal water accelerated the migration and precipitation of barium, affected the characteristics of the ore-forming fluids as well as http://www.999magnet.com the redox conditions of the environment. Different types of paleo-hydrothermal water determined the diversities of these barite-witherite deposits. There was carbonate hydrothermal water field near the Daba Mountain Arc Fault. Plentiful anions of CO32- got together in the backwater environment. At Wenyuhe and its neighborhood sulfate hydrothermal water fields have been detected. The upward removal of hydrocarbons (including CH4) had a great impact on the forming of witherite.Factors that led to the paragenesia and separation of witherite and barite included the differences of their solubilities, chemical coprecipitation of several kinds of minerals and the redox reaction between CH4 and SO42- in the hydrothermal background. Under the circumstances of tectonic movement in the later, stratigraphic overturning led to the changing of orebody occurrences and the appearance of several alternations. Meanwhile the components, textures, structures and other aspects of the consolidated rocks were also changed.
2012年8月7日星期二
The Study on Agglomeration of Cerium Oxalate Prepared by Precipitation
The Study on Agglomeration of Cerium Oxalate Prepared by Precipitation
In this paper, the precursor of CeO2 powders—Ce2(C2O4)3 was prepared by continuous precipitation method with cerium nitrate and oxalate as raw materials and precipitator respectively. The study includes mainly three parts: the first part is that the effect of operational conditions on correlation parameter of crystallization kinetics; the second part is that the effect of the different conditions of nucleation and growth process on the grain size, degree of agglomeration and particle size; the third mainly study on the preparation of large particle and Neodymium Magnets mathematical model.In the study on correlation parameter of crystallization process, the influence of operational parameters such as feed position, micro-mixing efficiency, feeding speed and reactant concentration on nucleation velocity and growth rate was studied. Nucleation velocity and growth rate were respectively obtained by fitting experimental data according to empirical formula as follows: B = 3. 01×108ΔC1.65, R 2 =0.91; G = 5 .17×10-6ΔC1.82, R 2 =0.97。
The process of precipitation was divided two processes: nucleation (nucleation take place mainly in this step, also partial growth) and growth process (there is mainly growth and agglomeration without nucleation). The effect of conditions of the precipitation on particles size of crystallizer and content of agglomeration was investigated in the nucleation process and http://www.999magnet.com optimum operational conditions of nucleation were obtained. The influence of different growth environment namely agitation speed, growth temperature, PH, electrolyte and dispersant (PEG1000) concentration on final agglomerates size was studied. The preparation of large particle Ce2(C2O4)3 was studied according to result of crystallization kinetics. In the study of agglomeration the relationship of particle size with specific power input and super saturation was obtained as follows: This relationship was generalized as follows:
In this paper, the precursor of CeO2 powders—Ce2(C2O4)3 was prepared by continuous precipitation method with cerium nitrate and oxalate as raw materials and precipitator respectively. The study includes mainly three parts: the first part is that the effect of operational conditions on correlation parameter of crystallization kinetics; the second part is that the effect of the different conditions of nucleation and growth process on the grain size, degree of agglomeration and particle size; the third mainly study on the preparation of large particle and Neodymium Magnets mathematical model.In the study on correlation parameter of crystallization process, the influence of operational parameters such as feed position, micro-mixing efficiency, feeding speed and reactant concentration on nucleation velocity and growth rate was studied. Nucleation velocity and growth rate were respectively obtained by fitting experimental data according to empirical formula as follows: B = 3. 01×108ΔC1.65, R 2 =0.91; G = 5 .17×10-6ΔC1.82, R 2 =0.97。
The process of precipitation was divided two processes: nucleation (nucleation take place mainly in this step, also partial growth) and growth process (there is mainly growth and agglomeration without nucleation). The effect of conditions of the precipitation on particles size of crystallizer and content of agglomeration was investigated in the nucleation process and http://www.999magnet.com optimum operational conditions of nucleation were obtained. The influence of different growth environment namely agitation speed, growth temperature, PH, electrolyte and dispersant (PEG1000) concentration on final agglomerates size was studied. The preparation of large particle Ce2(C2O4)3 was studied according to result of crystallization kinetics. In the study of agglomeration the relationship of particle size with specific power input and super saturation was obtained as follows: This relationship was generalized as follows:
The Preparation and Evaluation of TiO2 Series Materials for Environmental Purification
The Preparation and Evaluation of TiO2 Series Materials for Environmental Purification
human is facing increasingly industrial organic pollutants,air purification and other environmental problems,which is a serious threat to human health and quality of life.TiO2 Photocatalytic materials have large spectrum and bactericidal Performance,under the light, non-selectively oxidize(degrade) various organics and make them completely mineralize. Various pathogensin can be killed.Significant application prospects have been shown in water purification and treatment,indoor air purification and so on.Because of the efficiency,no secondary pollution strong magnets and direct use of solar energy, photocatalytic-oxidation technology attracts the research’s attention,but TiO2 only takes advantage of uitraviolet ray.The ultilization of visible light is very low.So technology of changing.TiO2’s cuality has been in the hot pot in recent years.TiO2 photocatalytic composite materials doped by Ce3+,Ce3+/Y3+ and La3+/Y3+ has been produced by sol-gel process based in the raw material of TNB.
In this thesis,several factors have been probed intensively,namely:doping effect on grain size,crysta microstructure of titanium dioxide and the photocatalytic degradation of the target of methylene blue solution under the violent.The effects of TiO2 photocatalytic properties by different elements and quantity of doping are also studied.It has been shown that using oxides can modify the band gap or act as charge separators of the photoinduced electron-hole pair thus enhance the http://www.chinamagnets.biz photocatalytic activity. Introduction of defects location or change of crystallinity in TiO2 lattice can effectively inhibit the resume between electron and hole,and transmission of the carrier can be happened in different energy level semiconductor and separated between the carrier effectively,extend life of carrier,thus raising the photocatalytic activity of TiO2.Through the control of synthesis conditions,Product characteristics can be controlled.So we can get the best photocatalyst preparation technology.Now the catalyst samples for the degradation of methylene blue solution have the highest catalytic efficiency.The valuable experimental data has been provide for new preparation method of TiO2 and high usage ratio of solar.It also has been provided referential value for the selection of wastewater treatment technics.
human is facing increasingly industrial organic pollutants,air purification and other environmental problems,which is a serious threat to human health and quality of life.TiO2 Photocatalytic materials have large spectrum and bactericidal Performance,under the light, non-selectively oxidize(degrade) various organics and make them completely mineralize. Various pathogensin can be killed.Significant application prospects have been shown in water purification and treatment,indoor air purification and so on.Because of the efficiency,no secondary pollution strong magnets and direct use of solar energy, photocatalytic-oxidation technology attracts the research’s attention,but TiO2 only takes advantage of uitraviolet ray.The ultilization of visible light is very low.So technology of changing.TiO2’s cuality has been in the hot pot in recent years.TiO2 photocatalytic composite materials doped by Ce3+,Ce3+/Y3+ and La3+/Y3+ has been produced by sol-gel process based in the raw material of TNB.
In this thesis,several factors have been probed intensively,namely:doping effect on grain size,crysta microstructure of titanium dioxide and the photocatalytic degradation of the target of methylene blue solution under the violent.The effects of TiO2 photocatalytic properties by different elements and quantity of doping are also studied.It has been shown that using oxides can modify the band gap or act as charge separators of the photoinduced electron-hole pair thus enhance the http://www.chinamagnets.biz photocatalytic activity. Introduction of defects location or change of crystallinity in TiO2 lattice can effectively inhibit the resume between electron and hole,and transmission of the carrier can be happened in different energy level semiconductor and separated between the carrier effectively,extend life of carrier,thus raising the photocatalytic activity of TiO2.Through the control of synthesis conditions,Product characteristics can be controlled.So we can get the best photocatalyst preparation technology.Now the catalyst samples for the degradation of methylene blue solution have the highest catalytic efficiency.The valuable experimental data has been provide for new preparation method of TiO2 and high usage ratio of solar.It also has been provided referential value for the selection of wastewater treatment technics.
Synthesis and Photoluminescence of BaCeO3:Eu3+ and SnO2:Eu3+ Oxide Phosphors
Synthesis and Photoluminescence of BaCeO3:Eu3+ and SnO2:Eu3+ Oxide Phosphors
The phosphor powders of BaCeO3:Eu3+, SnO2:Eu3+ and the core-shell-structured SiO2@SnO2:Eu3+ submicrospheres were synthesized by the solid state reaction method, sol-gel process, and precipitation process, respectively. The samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), photoluminescence (PL) and fluorescence lifetime measurement.For the phosphor powders of BaCeO3:Eu3+, XRD analysis showed that the formation of pure solid solution BaCe1-xEuxO3 up to 6 mol% of Eu3+ rare earth magnets concentration. The excitation spectra vary with the Eu3+ concentration and consist of an intense charge transfer band, host absorption band and some weak f-f transitions. The PL spectra, excited at 323 nm, mainly consist of 4f-4f emission transitions from the 5D0 excited level to the 7FJ (J= 0-4) levels of Eu3+. The PL intensity of the phosphor powders depents on the Eu3+ concentration and is quenched for the Eu3+ concentration of 15 mol%.
The lifetime of emission transition 5D0-7FJ (J= 1, 2) of Eu3+, is about 1 ms and decresses with increasing Eu3+ concentration in the samples.SnO2:Eu3+ phosphor powders were prepared by sol-gel method. XRD analysis showed the formation of pure tetragonal rutile crystalline phase of tin oxide up to 5 mol% of Eu3+ concentration. The excitation spectra consist of the charge transfer band, host absorption band and some weak f-f transitions. The PL spectra, excited at 310 nm, consist of 4f-4f emission transitions of Eu3+. The existence of three intense emission peaks belong to the 5D0-7F1 transitions indicats that the Eu3+ ions have been doped into the SnO2 host lattice and occupied the sites of the Sn4+ ions. The PL intensity of Sn1-xEuxO2 with various Eu3+ concentrations showed the optimal concentration of Eu3+ is 2 mol%.Sn1-xLixO2-δ:Eu3+ phosphor powders with various Li+ concentrations were prepared by ammonia precipitation method. SEM and XRD analysis http://www.chinamagnets.biz indicated that the Li+ doping enhances the crystallization and growth of SnO2. The PL spectra of Sn1-xLixO2-δ:Eu3+ phosphors indicated that the incorporation of Li+ ions into SnO2 lattice and the increase of sintered temperatures could induce a remarkable increase of photoluminescence intensity.The core-shell-structured SiO2@SnO2:Eu3+ submicrospheres were prepared by urea homogeneous precipitation method. SEM observations showed that the size of the core-shell-structured SiO2@SnO2:Eu3+ is in the range of 670 nm, and the thickness of shell is about 110 nm. The PL spectra indicated that the core-shell structure of SnO2:Eu3+ can improve its photoluminescence. The emission transition 5D0-7F1 (λem=587.6 nm) of the Eu3+ ions of the core-shell-structured SiO2@SnO2:Eu3+ have an average lifetime of about 20 ms.
The phosphor powders of BaCeO3:Eu3+, SnO2:Eu3+ and the core-shell-structured SiO2@SnO2:Eu3+ submicrospheres were synthesized by the solid state reaction method, sol-gel process, and precipitation process, respectively. The samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), photoluminescence (PL) and fluorescence lifetime measurement.For the phosphor powders of BaCeO3:Eu3+, XRD analysis showed that the formation of pure solid solution BaCe1-xEuxO3 up to 6 mol% of Eu3+ rare earth magnets concentration. The excitation spectra vary with the Eu3+ concentration and consist of an intense charge transfer band, host absorption band and some weak f-f transitions. The PL spectra, excited at 323 nm, mainly consist of 4f-4f emission transitions from the 5D0 excited level to the 7FJ (J= 0-4) levels of Eu3+. The PL intensity of the phosphor powders depents on the Eu3+ concentration and is quenched for the Eu3+ concentration of 15 mol%.
The lifetime of emission transition 5D0-7FJ (J= 1, 2) of Eu3+, is about 1 ms and decresses with increasing Eu3+ concentration in the samples.SnO2:Eu3+ phosphor powders were prepared by sol-gel method. XRD analysis showed the formation of pure tetragonal rutile crystalline phase of tin oxide up to 5 mol% of Eu3+ concentration. The excitation spectra consist of the charge transfer band, host absorption band and some weak f-f transitions. The PL spectra, excited at 310 nm, consist of 4f-4f emission transitions of Eu3+. The existence of three intense emission peaks belong to the 5D0-7F1 transitions indicats that the Eu3+ ions have been doped into the SnO2 host lattice and occupied the sites of the Sn4+ ions. The PL intensity of Sn1-xEuxO2 with various Eu3+ concentrations showed the optimal concentration of Eu3+ is 2 mol%.Sn1-xLixO2-δ:Eu3+ phosphor powders with various Li+ concentrations were prepared by ammonia precipitation method. SEM and XRD analysis http://www.chinamagnets.biz indicated that the Li+ doping enhances the crystallization and growth of SnO2. The PL spectra of Sn1-xLixO2-δ:Eu3+ phosphors indicated that the incorporation of Li+ ions into SnO2 lattice and the increase of sintered temperatures could induce a remarkable increase of photoluminescence intensity.The core-shell-structured SiO2@SnO2:Eu3+ submicrospheres were prepared by urea homogeneous precipitation method. SEM observations showed that the size of the core-shell-structured SiO2@SnO2:Eu3+ is in the range of 670 nm, and the thickness of shell is about 110 nm. The PL spectra indicated that the core-shell structure of SnO2:Eu3+ can improve its photoluminescence. The emission transition 5D0-7F1 (λem=587.6 nm) of the Eu3+ ions of the core-shell-structured SiO2@SnO2:Eu3+ have an average lifetime of about 20 ms.
2012年8月3日星期五
Study of Preparation and Comparation of Luminescence of Series of MQq Coordination Complexes
Study of Preparation and Comparation of Luminescence of Series of MQq Coordination Complexes
Content: Six novel M(M=Al, Zn, Cd, Pr, Cu, Co)Qq and four novelM(M=Sm, Nd, Eu, Tb)-Phen coordination complexes have beensynthesized under hydrothermal condition. The crystal structures of fivenovel coordination complexes are determined by X-ray diffraction andtheir formulas are presented as following: (1)AlQ3 (7)Tb(phen)2(NO3)3 (2)ZnQ3 (8)Nd(phen)2(NO3)2(CH3COO) (3)CdQ3 (9)Sm(phen)2(NO3)2(CH3COO) (4)PrQ3 (10)Eu(phen)2(NO3)2(CH3COO) (5)CoQ3 (6)CuQ2Their photoluminescence and electroluminescence are mainly studied.The photoluminescence of complexes (1)～(4) can exhibit intense greenlight. Their Block Neodymium magnets electroluminescence can also exhibit intense light. Thephotoluminescence of complexes (7), (9), (10) can exhibit intense light,but their electroluminescence can not exhibit intense light. We found thatthrough quantitative analysis the influence between organic ligands andcenter metal can change the intramolecular energy leve, which canincreace quantum efficiency. At the same time, we have fabricatedvarious organic light-emitting devices (OLEDs) with these complexes,and found some complexes can not be used in electroluminescence. Wewant to synthesize more coordination complexes of metal with8-hydroxyquinoline and derivation which can be applied in OLEDs, andwide the scope of organic http://www.999magnet.com luminescence materials. In addition, their IR,UV-VIS-NIR spectrum and element analysis are measured andinvestigated which are important help to further analyse and contrast theluminescent property.
Content: Six novel M(M=Al, Zn, Cd, Pr, Cu, Co)Qq and four novelM(M=Sm, Nd, Eu, Tb)-Phen coordination complexes have beensynthesized under hydrothermal condition. The crystal structures of fivenovel coordination complexes are determined by X-ray diffraction andtheir formulas are presented as following: (1)AlQ3 (7)Tb(phen)2(NO3)3 (2)ZnQ3 (8)Nd(phen)2(NO3)2(CH3COO) (3)CdQ3 (9)Sm(phen)2(NO3)2(CH3COO) (4)PrQ3 (10)Eu(phen)2(NO3)2(CH3COO) (5)CoQ3 (6)CuQ2Their photoluminescence and electroluminescence are mainly studied.The photoluminescence of complexes (1)～(4) can exhibit intense greenlight. Their Block Neodymium magnets electroluminescence can also exhibit intense light. Thephotoluminescence of complexes (7), (9), (10) can exhibit intense light,but their electroluminescence can not exhibit intense light. We found thatthrough quantitative analysis the influence between organic ligands andcenter metal can change the intramolecular energy leve, which canincreace quantum efficiency. At the same time, we have fabricatedvarious organic light-emitting devices (OLEDs) with these complexes,and found some complexes can not be used in electroluminescence. Wewant to synthesize more coordination complexes of metal with8-hydroxyquinoline and derivation which can be applied in OLEDs, andwide the scope of organic http://www.999magnet.com luminescence materials. In addition, their IR,UV-VIS-NIR spectrum and element analysis are measured andinvestigated which are important help to further analyse and contrast theluminescent property.
Research of the New Materials of Long-lasting Phosphors and Upconversion Luminescence
Research of the New Materials of Long-lasting Phosphors and Upconversion Luminescence
Long-lasting phosphorescence and upconversion luminescence are two important area in luminescence material, which can be used in many fields, including illumination, decoration and optical deta storage. In this thesis, several long afterglow and upconversion luminescence materials in oxysulfide were reported. Furthermore, the optical characteristics and the mechanism of the occurrence of these materials were discussed carefully. This thesis is divided into Magnetic lifter seven chapters.In the first chapter, one briefly introduce of the development about the persistent afterglow luminescence and upconversion luminescence, as well as the current survey, research significants and the results in this thesis.In the second chapter, the afterglow luminescence of Gd2O2S: Ti was reported, and the mechanism of the hole and electron was synthesized.In the third chapter, we discussed the long-lasting luminescence of Gd2O2S: Er, Ti, and give the mechanism of energy transfer from Ti to Er. In the fourth chapter, some rare earth ions like La, Gd, Lu were doped into the Y2O2S host, and the afterglow luminescence was checked; meanwhile the mechanism was discussed.In the fifth chapter, we introduce the the upconversion luminescence in Y2O2S host according the their optical spectra, while the Er, Yb, Tm, Ho, Sm were doped.In the sixth chapter, the up-conversion luminescence materials yttrium oxysulfide doped by yb3+/Er3+ were systhesized by oprecipitation with their subsequent thermal decomposition in presence of sulphur, http://www.999magnet.com the luminescence properties and morphology from these products systhesized were contraled by different synthsis temperature and time.In the seventh chapter, the self-active luminescence of YOR(R=F,Cl,Br) were reported; also the defect type were analyzed with thermoluminescence spectra.
Long-lasting phosphorescence and upconversion luminescence are two important area in luminescence material, which can be used in many fields, including illumination, decoration and optical deta storage. In this thesis, several long afterglow and upconversion luminescence materials in oxysulfide were reported. Furthermore, the optical characteristics and the mechanism of the occurrence of these materials were discussed carefully. This thesis is divided into Magnetic lifter seven chapters.In the first chapter, one briefly introduce of the development about the persistent afterglow luminescence and upconversion luminescence, as well as the current survey, research significants and the results in this thesis.In the second chapter, the afterglow luminescence of Gd2O2S: Ti was reported, and the mechanism of the hole and electron was synthesized.In the third chapter, we discussed the long-lasting luminescence of Gd2O2S: Er, Ti, and give the mechanism of energy transfer from Ti to Er. In the fourth chapter, some rare earth ions like La, Gd, Lu were doped into the Y2O2S host, and the afterglow luminescence was checked; meanwhile the mechanism was discussed.In the fifth chapter, we introduce the the upconversion luminescence in Y2O2S host according the their optical spectra, while the Er, Yb, Tm, Ho, Sm were doped.In the sixth chapter, the up-conversion luminescence materials yttrium oxysulfide doped by yb3+/Er3+ were systhesized by oprecipitation with their subsequent thermal decomposition in presence of sulphur, http://www.999magnet.com the luminescence properties and morphology from these products systhesized were contraled by different synthsis temperature and time.In the seventh chapter, the self-active luminescence of YOR(R=F,Cl,Br) were reported; also the defect type were analyzed with thermoluminescence spectra.
Study on Fused Iron Catalysts for Fischer-Tropsch Synthesis
Study on Fused Iron Catalysts for Fischer-Tropsch Synthesis
The Fischer-Tropsch synthesis (FTS) offers the potential of converting syngas into high value chemicals. Although several metals are active for the FTS, only iron and cobalt catalysts appear economically feasible on an industrial scale. Controlling selectivity is an important aspect of FTS catalyst development, depending on promoters and the process conditions employed.The precursors、promoters、reaction conditions and son were studyed in this paper, and characterized by means of XRD, TPR, BET, and TPD and so on to provide better insight into the relationship therein. Main results from this work were as follows.It was found that there was little effect of different precursor for the conversion of Fischer-Tropsch synthesis. The lower CH4 and CO2 Neodymium Magnets were produced by the precursor of Fe3O4 - FeO coexisted, the CO adsorption was better, but the H2 adsorption was not good, it was maybe the more K contents on the surface.With K added the carbon number distribution was presented by two values of a. With the increase of Potassium content, the adsorption of CO was enhanced, the beginning reduction temperature of the catalysts was decreased, carbonization of catalyst was enhanced, The interactions of Al、Ca、Fe were also enhanced, the conversion was increased at first and then flattened out at high conversion levels, especially the formation of methane was suppressed, but carbon deposition was increased, the selectivity of olefins and higher molecular weight products were enhanced and the WGS reaction was facilitated.As the structural promoters Al2O3, CaO, which were no effect on the F-T synthesis conversion, the effect of K was weakened, WGS reaction was restrained by added CaO. To some extent, the addition of rare earth oxide, then the FexC phase http://www.999magnet.com of the XRD patters was increased.The study of reaction conditions indicated that the lower temperature, H2/CO ration and lower pace velocity, the formation of methane was greatly suppressed, but the pressure was not clearly. The partile size decreased to 0.1 mm, the internal diffusion was eliminated.
The Fischer-Tropsch synthesis (FTS) offers the potential of converting syngas into high value chemicals. Although several metals are active for the FTS, only iron and cobalt catalysts appear economically feasible on an industrial scale. Controlling selectivity is an important aspect of FTS catalyst development, depending on promoters and the process conditions employed.The precursors、promoters、reaction conditions and son were studyed in this paper, and characterized by means of XRD, TPR, BET, and TPD and so on to provide better insight into the relationship therein. Main results from this work were as follows.It was found that there was little effect of different precursor for the conversion of Fischer-Tropsch synthesis. The lower CH4 and CO2 Neodymium Magnets were produced by the precursor of Fe3O4 - FeO coexisted, the CO adsorption was better, but the H2 adsorption was not good, it was maybe the more K contents on the surface.With K added the carbon number distribution was presented by two values of a. With the increase of Potassium content, the adsorption of CO was enhanced, the beginning reduction temperature of the catalysts was decreased, carbonization of catalyst was enhanced, The interactions of Al、Ca、Fe were also enhanced, the conversion was increased at first and then flattened out at high conversion levels, especially the formation of methane was suppressed, but carbon deposition was increased, the selectivity of olefins and higher molecular weight products were enhanced and the WGS reaction was facilitated.As the structural promoters Al2O3, CaO, which were no effect on the F-T synthesis conversion, the effect of K was weakened, WGS reaction was restrained by added CaO. To some extent, the addition of rare earth oxide, then the FexC phase http://www.999magnet.com of the XRD patters was increased.The study of reaction conditions indicated that the lower temperature, H2/CO ration and lower pace velocity, the formation of methane was greatly suppressed, but the pressure was not clearly. The partile size decreased to 0.1 mm, the internal diffusion was eliminated.
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