以200 m Pa·s和500 m Pa·s的端乙烯基硅油为基体硅油、活性氢质量分数0.05%含氢硅油为交联剂,添加不同粒径球形氧化铝以不同比例复配的导热填料制得低渗油高填充导热硅凝胶。研究了不同粒径球形氧化铝与基体硅油黏度对基胶黏...以200 m Pa·s和500 m Pa·s的端乙烯基硅油为基体硅油、活性氢质量分数0.05%含氢硅油为交联剂,添加不同粒径球形氧化铝以不同比例复配的导热填料制得低渗油高填充导热硅凝胶。研究了不同粒径球形氧化铝与基体硅油黏度对基胶黏度及氧化铝最大填充量的影响,探究了γ-巯丙基三甲氧基硅烷(KH590)对硅凝胶导热性能的影响,基体硅油黏度、活性氢与硅乙烯基物质的量之比及氧化铝填充量对硅凝胶硬度、密度、热导率及力学强度的影响。重点研究了氧化铝复配种类与比例对硅凝胶抗渗油性能及热稳定性的影响机制。结果表明,以不同黏度的端乙烯基硅油为基体硅油,活性氢质量分数0.05%含氢硅油为交联剂,添加不同粒径的球形氧化铝复配导热填料可制得低渗油高填充导热硅凝胶;在采用单一粒径球形氧化铝时,同一填充量下,20μm球形氧化铝对基胶的增黏不明显且最大填充量较高,可达1 500份;适当增加硅烷偶联剂KH590用量能有效提高硅凝胶的导热性能,较佳用量为2.00%;采用200 m Pa·s的端乙烯基硅油为基体硅油,活性氢与硅乙烯基物质的量之比为0.8∶1,单独采用600份20μm球形氧化铝作导热填料时,硅凝胶具有较佳的硬度、密度、热导率及拉伸强度,邵氏OO硬度为67,密度为1.83 g/cm^(3),热导率为3.69 W/(m·K),拉伸强度为1.95 MPa;采用不同粒径球形氧化铝复配时,导热硅凝胶的热导率均高于采用单一粒径球形氧化铝填充的硅凝胶,导热填料采用20μm与5μm球形氧化铝按质量比2∶1复配时硅凝胶导热性能较佳,热导率为4.72 W/(m·K);由于球形氧化铝表面硅烷化后与基体硅油的缠绕及填料表面巯基与一定量残留双键的氢键效应,导热填料采用20μm与5μm球形氧化铝按质量比2∶1复配时硅凝胶具有较佳的抗渗油性能及热稳定性,渗油比仅为1.0476,硅凝胶质量损失率5%时的温度为331℃,700℃时残余质量分数为89.10%。展开更多
The CdS/spherical g-C3N4 n-n heterojunction photocatalyst was fabricated via a solvothermal method.The tetracycline was used to characterize the photocatalytic properties of the as-developed hybrids.The photocatalytic...The CdS/spherical g-C3N4 n-n heterojunction photocatalyst was fabricated via a solvothermal method.The tetracycline was used to characterize the photocatalytic properties of the as-developed hybrids.The photocatalytic degradation mechanism of the as-developed heterojunction photocatalyst was also analyzed.Research results show that CdS nanoparticles are well dispersed in the surface layer of spherical g-C3N4.Moreover,the mass ratio of CdS to spherical g-C3N4 will influence the photocatalytic activity of the asdeveloped composites,which shows the trend of first increasing and then decreasing as it increased.When the mass ratio is 7:1,in 25 min,the as-developed heterojunction shows 93.2%of the maximum photocatalytic efficiency and still exhibits 83.6%after 5 times cycle testing.Moreover,the as-developed hybrids can accelerate the electron transport and improve the separation efficiency of photo-generated carriers compared with pure samples.In addition,the holes and superoxide radicals are dominating active species during the photocatalytic degradation process.展开更多
The effect Of Y2O3 as additive to the positive electrode on the high-temperature performances of the Ni-MH batteries was studied. The specific capacities of the positive electrode in Ni-MH battery at higher temperatur...The effect Of Y2O3 as additive to the positive electrode on the high-temperature performances of the Ni-MH batteries was studied. The specific capacities of the positive electrode in Ni-MH battery at higher temperatures are much lower than usual. In order to improve high-temperature performances, charge/discharge curves of the Ni(OH)(2) electrodes with different amounts Of Y2O3 it different temperatures were studied. It is found that the specific capacities of the spherical Ni (OH)(2) with Y2O3 as additive are much higher than those of the regular at higher temperatures. The specific capacity of Ni (OH)(2) containing 1% Y2O3 at 0.2C C/D rate is 35% higher than that of the regular. The specific capacity of Ni (OH)(2) containing 0.2% Y2O3 at 1C C/D rate is 15% higher than that of the regular. Mechanism Of Y2O3 improving high temperature performances of Ni(OH)(2) electrode was also discussed in detail.展开更多
Spherical Bi2O3 powder prepared by plasma chemical vapor reaction and aqueous chemical precipitation is studied. The superfine spherical Bi2O3 powder with an average diameter of 1 μm is made by plasma process. During...Spherical Bi2O3 powder prepared by plasma chemical vapor reaction and aqueous chemical precipitation is studied. The superfine spherical Bi2O3 powder with an average diameter of 1 μm is made by plasma process. During the precipitation process, the micrograph of the Bi2O3 powder can be controlled through the reaction temperature, the rate of addition of the precipitation reagent, the reaction time and the amount of the dispersant. Accordingly, spherical Bi2O3 powder with diameters ranging from 2μm to 3μm is prepared. The spherical Bi2O3 particles have such advantages as uniform size distribution and excellent dispersing property. ZnO varistors made from the resultant powder exhibit properties of a low discharge voltage ratio, great eligibility coefficient measured by a rectangle wave of 2 ins 800 A and good stability in the above characteristics.展开更多
For the purpose of the important high-temperature charge-discharge performances of spherical Ni(OH)2 used as positive materials for Ni-MH batteries, Yb(OH)3 and Er(OH)3 were used for surface coating of spherical Ni(OH...For the purpose of the important high-temperature charge-discharge performances of spherical Ni(OH)2 used as positive materials for Ni-MH batteries, Yb(OH)3 and Er(OH)3 were used for surface coating of spherical Ni(OH)2 to improve its high-temperature properties. The coated spherical Ni(OH)2 was prepared by chemically coprecipitation of Yb(OH)3 and Er(OH)3 on the surface of spherical Ni(OH)2, respectively. The products were characterized by X-ray diffraction(XRD) and scanning electron microscope(SEM). The X-ray analysis showed that the structure of the coated spherical Ni(OH)2 was still β-Ni(OH)2. The SEM studies revealed that coating layer uniformly covered the surface of spherical Ni(OH)2. The electrochemical studies revealed that coating of Yb(OH)3 and Er(OH)3 exhibited superior performance such as high discharge capacity, excellent charge-discharge properties at high-discharge rate at 65 ℃. The charge acceptance was above 85% at 1C rate at 65 ℃. The discharge capacity approached to 230 mAh·g-1 at 0.2C rate, which even reached 270 mAh·g-1 at 1C rate for both Yb(OH)3 and Er(OH)3 coated spherical Ni(OH)2, where the discharge capacity for uncoated one was only 250 mAh·g-1 . The cyclic voltammetry analysis of spherical Ni(OH)2 showed that the oxidation potential, the oxygen evolution potential, and the difference between them increased after the coating both at 25 and 65 ℃. It was shown that the Yb(OH)3 and Er(OH)3 coating is an effective way to improve the high-temperature performance of spherical Ni(OH)2 for Ni-MH batteries. The studies showed that Yb(OH)3 and Er(OH)3 coated spherical Ni(OH)2 would be a promising material of Ni-MH batteries for hybrid vehicle (HEVs), electric vehicles(EVs) and rapid charge devices due to excellent high rate charge-discharge performance.展开更多
In this paper a new spherical actuator is designed and its advantages are compared to an existing spherical actuator, which function is limited by several design bottlenecks. First the output torque is too small. Seco...In this paper a new spherical actuator is designed and its advantages are compared to an existing spherical actuator, which function is limited by several design bottlenecks. First the output torque is too small. Second, the attitude is difficult to be accurately detected. The new three-dimen- sional magnetic pole array can solve these major problems. The new actuator features an outer rotor with multiple permanent magnet （PM） poles. Using an analytical solution and the finite element so- lution simulation, the feasibility of the approach is verified. A prototype was developed, tested, and experiments were conducted to obtain the practical value of the magnetic flux density.展开更多
Nickel-metal hydride （Ni/MH） batteries are one of promising batteries for electric vehicle applications, but at high temperature the charge efficiency of nickel electrode is very low. In order to improve the high-te...Nickel-metal hydride （Ni/MH） batteries are one of promising batteries for electric vehicle applications, but at high temperature the charge efficiency of nickel electrode is very low. In order to improve the high-temperature-efficiency of nickel electrode, spherical nickel hydroxide mixed with various ratios of Lu2O3 was used as active material of pasted nickel electrodes. The results of charge/discharge experiments, cyclic voltammetric measurements and XRD characterizations have shown that after addition of Lu2O3, the oxygen evolution overpotcntial is elevated much, the charge efficiency of nickel electrode at high temperature is greatly improved and the content of β-NiOOH phase increases in charged electrodes. In addition, the mixed ratio of Lu2O3 has different effects on high temperature performances of nickel electrode at different charge/discharge currents, 3.5 % is the optimum mixed ratio, and the action of Lu2O3 on high temperature electrochemical behaviors is more apparent when nickel electrodes are charged at small current than large current.展开更多
The magnetic fusion reactor using the advanced D-3He fuels has the advantage of much less-neutron productions so that the consequent damages to the first wall are less serious. If the establishment of this kind of rea...The magnetic fusion reactor using the advanced D-3He fuels has the advantage of much less-neutron productions so that the consequent damages to the first wall are less serious. If the establishment of this kind of reactor becomes realistic, the exploration of 3He on the moon will be largely motivated. Based on recent progresses in the spherical torus (ST) research, we have physically designed a D-3He fusion reactor using the extrapolated results from the ST experiments and also the present-day tokamak scaling. It is found that the reactor size significantly depends on the wall reflection coefficient of the synchrotron radiation and of the impurity contaminations. The secondary reaction between D-D that promptly leads to the D-T reaction producing 14 MeV neutrons is also estimated. Comparison of this D-3He ST reactor with the D-T reactor is made.展开更多
Rehabilitation devices help to recover the physical abilities of patients. This study aims to develop a portable rehabilitation device that is safe to use when?patients are holding it by hands. In a previous study, to...Rehabilitation devices help to recover the physical abilities of patients. This study aims to develop a portable rehabilitation device that is safe to use when?patients are holding it by hands. In a previous study, to realize a home rehabilitation device, a flexible spherical actuator that can provide motion to patients was developed. In this study, to measure the relative position between both handling stages, a 3D coordinate measuring device using three wire-type linear potentiometers and an embedded controller was proposed and tested. In this paper, the spherical actuator with built-in 3D coordinate measuring device is described. The measuring method and experimental results obtained are also presented. The tracking position control of the actuator using the measuring device was carried out. As a result, the position of the handling stages can be successfully controlled using the feedback signal from the tested?measuring device.展开更多
文摘以200 m Pa·s和500 m Pa·s的端乙烯基硅油为基体硅油、活性氢质量分数0.05%含氢硅油为交联剂,添加不同粒径球形氧化铝以不同比例复配的导热填料制得低渗油高填充导热硅凝胶。研究了不同粒径球形氧化铝与基体硅油黏度对基胶黏度及氧化铝最大填充量的影响,探究了γ-巯丙基三甲氧基硅烷(KH590)对硅凝胶导热性能的影响,基体硅油黏度、活性氢与硅乙烯基物质的量之比及氧化铝填充量对硅凝胶硬度、密度、热导率及力学强度的影响。重点研究了氧化铝复配种类与比例对硅凝胶抗渗油性能及热稳定性的影响机制。结果表明,以不同黏度的端乙烯基硅油为基体硅油,活性氢质量分数0.05%含氢硅油为交联剂,添加不同粒径的球形氧化铝复配导热填料可制得低渗油高填充导热硅凝胶;在采用单一粒径球形氧化铝时,同一填充量下,20μm球形氧化铝对基胶的增黏不明显且最大填充量较高,可达1 500份;适当增加硅烷偶联剂KH590用量能有效提高硅凝胶的导热性能,较佳用量为2.00%;采用200 m Pa·s的端乙烯基硅油为基体硅油,活性氢与硅乙烯基物质的量之比为0.8∶1,单独采用600份20μm球形氧化铝作导热填料时,硅凝胶具有较佳的硬度、密度、热导率及拉伸强度,邵氏OO硬度为67,密度为1.83 g/cm^(3),热导率为3.69 W/(m·K),拉伸强度为1.95 MPa;采用不同粒径球形氧化铝复配时,导热硅凝胶的热导率均高于采用单一粒径球形氧化铝填充的硅凝胶,导热填料采用20μm与5μm球形氧化铝按质量比2∶1复配时硅凝胶导热性能较佳,热导率为4.72 W/(m·K);由于球形氧化铝表面硅烷化后与基体硅油的缠绕及填料表面巯基与一定量残留双键的氢键效应,导热填料采用20μm与5μm球形氧化铝按质量比2∶1复配时硅凝胶具有较佳的抗渗油性能及热稳定性,渗油比仅为1.0476,硅凝胶质量损失率5%时的温度为331℃,700℃时残余质量分数为89.10%。
基金Funded by the Natural Science Foundation of Hebei Province,China(Nos.E2019210251 and B2019210331).
文摘The CdS/spherical g-C3N4 n-n heterojunction photocatalyst was fabricated via a solvothermal method.The tetracycline was used to characterize the photocatalytic properties of the as-developed hybrids.The photocatalytic degradation mechanism of the as-developed heterojunction photocatalyst was also analyzed.Research results show that CdS nanoparticles are well dispersed in the surface layer of spherical g-C3N4.Moreover,the mass ratio of CdS to spherical g-C3N4 will influence the photocatalytic activity of the asdeveloped composites,which shows the trend of first increasing and then decreasing as it increased.When the mass ratio is 7:1,in 25 min,the as-developed heterojunction shows 93.2%of the maximum photocatalytic efficiency and still exhibits 83.6%after 5 times cycle testing.Moreover,the as-developed hybrids can accelerate the electron transport and improve the separation efficiency of photo-generated carriers compared with pure samples.In addition,the holes and superoxide radicals are dominating active species during the photocatalytic degradation process.
文摘The effect Of Y2O3 as additive to the positive electrode on the high-temperature performances of the Ni-MH batteries was studied. The specific capacities of the positive electrode in Ni-MH battery at higher temperatures are much lower than usual. In order to improve high-temperature performances, charge/discharge curves of the Ni(OH)(2) electrodes with different amounts Of Y2O3 it different temperatures were studied. It is found that the specific capacities of the spherical Ni (OH)(2) with Y2O3 as additive are much higher than those of the regular at higher temperatures. The specific capacity of Ni (OH)(2) containing 1% Y2O3 at 0.2C C/D rate is 35% higher than that of the regular. The specific capacity of Ni (OH)(2) containing 0.2% Y2O3 at 1C C/D rate is 15% higher than that of the regular. Mechanism Of Y2O3 improving high temperature performances of Ni(OH)(2) electrode was also discussed in detail.
基金Technology Innovation Foundation of Middle-minor Enterprises of Science and Technology from Ministryof Science and Technology (No. 19995103020074, 20003403023018)
文摘Spherical Bi2O3 powder prepared by plasma chemical vapor reaction and aqueous chemical precipitation is studied. The superfine spherical Bi2O3 powder with an average diameter of 1 μm is made by plasma process. During the precipitation process, the micrograph of the Bi2O3 powder can be controlled through the reaction temperature, the rate of addition of the precipitation reagent, the reaction time and the amount of the dispersant. Accordingly, spherical Bi2O3 powder with diameters ranging from 2μm to 3μm is prepared. The spherical Bi2O3 particles have such advantages as uniform size distribution and excellent dispersing property. ZnO varistors made from the resultant powder exhibit properties of a low discharge voltage ratio, great eligibility coefficient measured by a rectangle wave of 2 ins 800 A and good stability in the above characteristics.
文摘For the purpose of the important high-temperature charge-discharge performances of spherical Ni(OH)2 used as positive materials for Ni-MH batteries, Yb(OH)3 and Er(OH)3 were used for surface coating of spherical Ni(OH)2 to improve its high-temperature properties. The coated spherical Ni(OH)2 was prepared by chemically coprecipitation of Yb(OH)3 and Er(OH)3 on the surface of spherical Ni(OH)2, respectively. The products were characterized by X-ray diffraction(XRD) and scanning electron microscope(SEM). The X-ray analysis showed that the structure of the coated spherical Ni(OH)2 was still β-Ni(OH)2. The SEM studies revealed that coating layer uniformly covered the surface of spherical Ni(OH)2. The electrochemical studies revealed that coating of Yb(OH)3 and Er(OH)3 exhibited superior performance such as high discharge capacity, excellent charge-discharge properties at high-discharge rate at 65 ℃. The charge acceptance was above 85% at 1C rate at 65 ℃. The discharge capacity approached to 230 mAh·g-1 at 0.2C rate, which even reached 270 mAh·g-1 at 1C rate for both Yb(OH)3 and Er(OH)3 coated spherical Ni(OH)2, where the discharge capacity for uncoated one was only 250 mAh·g-1 . The cyclic voltammetry analysis of spherical Ni(OH)2 showed that the oxidation potential, the oxygen evolution potential, and the difference between them increased after the coating both at 25 and 65 ℃. It was shown that the Yb(OH)3 and Er(OH)3 coating is an effective way to improve the high-temperature performance of spherical Ni(OH)2 for Ni-MH batteries. The studies showed that Yb(OH)3 and Er(OH)3 coated spherical Ni(OH)2 would be a promising material of Ni-MH batteries for hybrid vehicle (HEVs), electric vehicles(EVs) and rapid charge devices due to excellent high rate charge-discharge performance.
基金Supported by the National Key Basic Research and Development Program(973 Program)(2014CB046405)
文摘In this paper a new spherical actuator is designed and its advantages are compared to an existing spherical actuator, which function is limited by several design bottlenecks. First the output torque is too small. Second, the attitude is difficult to be accurately detected. The new three-dimen- sional magnetic pole array can solve these major problems. The new actuator features an outer rotor with multiple permanent magnet （PM） poles. Using an analytical solution and the finite element so- lution simulation, the feasibility of the approach is verified. A prototype was developed, tested, and experiments were conducted to obtain the practical value of the magnetic flux density.
文摘Nickel-metal hydride （Ni/MH） batteries are one of promising batteries for electric vehicle applications, but at high temperature the charge efficiency of nickel electrode is very low. In order to improve the high-temperature-efficiency of nickel electrode, spherical nickel hydroxide mixed with various ratios of Lu2O3 was used as active material of pasted nickel electrodes. The results of charge/discharge experiments, cyclic voltammetric measurements and XRD characterizations have shown that after addition of Lu2O3, the oxygen evolution overpotcntial is elevated much, the charge efficiency of nickel electrode at high temperature is greatly improved and the content of β-NiOOH phase increases in charged electrodes. In addition, the mixed ratio of Lu2O3 has different effects on high temperature performances of nickel electrode at different charge/discharge currents, 3.5 % is the optimum mixed ratio, and the action of Lu2O3 on high temperature electrochemical behaviors is more apparent when nickel electrodes are charged at small current than large current.
基金The project supported by the National Nature Science Foundation of China (No. 10375018)
文摘The magnetic fusion reactor using the advanced D-3He fuels has the advantage of much less-neutron productions so that the consequent damages to the first wall are less serious. If the establishment of this kind of reactor becomes realistic, the exploration of 3He on the moon will be largely motivated. Based on recent progresses in the spherical torus (ST) research, we have physically designed a D-3He fusion reactor using the extrapolated results from the ST experiments and also the present-day tokamak scaling. It is found that the reactor size significantly depends on the wall reflection coefficient of the synchrotron radiation and of the impurity contaminations. The secondary reaction between D-D that promptly leads to the D-T reaction producing 14 MeV neutrons is also estimated. Comparison of this D-3He ST reactor with the D-T reactor is made.
文摘Rehabilitation devices help to recover the physical abilities of patients. This study aims to develop a portable rehabilitation device that is safe to use when?patients are holding it by hands. In a previous study, to realize a home rehabilitation device, a flexible spherical actuator that can provide motion to patients was developed. In this study, to measure the relative position between both handling stages, a 3D coordinate measuring device using three wire-type linear potentiometers and an embedded controller was proposed and tested. In this paper, the spherical actuator with built-in 3D coordinate measuring device is described. The measuring method and experimental results obtained are also presented. The tracking position control of the actuator using the measuring device was carried out. As a result, the position of the handling stages can be successfully controlled using the feedback signal from the tested?measuring device.
