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1.
铝掺杂氧化锌(AZO)薄膜的电学性质研究   总被引:9,自引:2,他引:7  
马瑾  计峰 《太阳能学报》1995,16(2):216-219
真空蒸发醋酸锌和氯化铝,在加热的玻璃基片上制备出铝掺杂的氧化锌透明导电薄膜。研究了薄膜的结构和电导率随掺杂功率的变化以及真空退火处理对薄膜电导率的影响。  相似文献
2.
蒸发制备ZnO薄膜的结构及光学电学特性的研究   总被引:8,自引:2,他引:6  
马瑾  计峰 《太阳能学报》1995,16(2):181-184
以乙酸锌作为蒸发物质,采用真空蒸发技术,在加热的玻璃衬底上制备出高捏的ZnO透明导电薄膜,并对其结构,光学和电学特性进行了研究。  相似文献
3.
涡流法判断铝硅合金活塞变质效果的方法   总被引:6,自引:1,他引:5  
曾辉  余坤 《内燃机工程》2000,21(3):50-53
铝硅合金变质前后组织中共晶硅的形态发生明显变化,导致材料电导率改变,应用涡流传感器采集不同变质效果的试块或活塞的电信号,信信号的大小可判断铸件的变质效果。  相似文献
4.
Various trivalent oxides were added as co-dopants to gadolinia-doped ceria (GDC) electrolyte used for solid oxide fuel cells at up to 5 mol%. An examination was made on how they affect the electrical conductivity of the electrolyte and, eventually, the open-circuit voltage (OCV) of a unit cell. Through a comparison of the thermal expansion coefficients (TEC), it was investigated whether or not the co-doped electrolytes are thermomechanically compatible with other cell components. The addition of co-dopants generally improve the electrical properties of the electrolyte by yielding greater OCV values and not changing the TEC significantly (5% at most), except in the case of Pr. Among the electrolytes examined, the one co-doped with Sm (3 mol%) shows the best improvement in performance.  相似文献
5.
A review of conduction phenomena in Li-ion batteries   总被引:2,自引:0,他引:2  
Conduction has been one of the main barriers to further improvements in Li-ion batteries and is expected to remain so for the foreseeable future. In an effort to gain a better understanding of the conduction phenomena in Li-ion batteries and enable breakthrough technologies, a comprehensive survey of conduction phenomena in all components of a Li-ion cell incorporating theoretical, experimental, and simulation studies, is presented here. Included are a survey of the fundamentals of electrical and ionic conduction theories; a survey of the critical results, issues and challenges with respect to ionic and electronic conduction in the cathode, anode and electrolyte; a review of the relationship between electrical and ionic conduction for three cathode materials: LiCoO2, LiMn2O4, LiFePO4; a discussion of phase change in graphitic anodes and how it relates to diffusivity and conductivity; and the key conduction issues with organic liquid, solid-state and ionic liquid electrolytes.  相似文献
6.
Self-supported supercapacitor electrodes with remarkably high specific capacitance have been developed by homogeneously coating polypyrrole (PPy) on multi-walled carbon nanotube (MWCNT) membranes. Polypyrrole can be deposited around the individual MWCNTs in a uniform manner throughout the MWCNT membrane via a pulsed electrochemical deposition method. This approach optimizes the pseudocapacitance of the membrane. Electrochemical data and Raman spectra indicate that the high specific capacitance is not only due to more uniform PPy coating, but also higher redox activity that is likely associated with a more ordered PPy packing. Such composite membranes can be directly used as supercapacitor electrodes without backing metal films or binders. A remarkable specific capacitance of 427 F g−1 has been achieved using 5-s electrodeposition pulses. This technique provides a viable solution for developing high-performance electrical energy storage devices.  相似文献
7.
The technology of polymer electrolyte membrane (PEM) fuel cells is dependent on the performance of bipolar plates. There is a strong relationship between the material used in the manufacturing of the bipolar plate and its final properties. Graphite-polymer composite bipolar plates are well-established commercial products. Several other carbon based fillers are tested. Carbon nanotubes, carbon fibers, carbon black, graphite nanoplatelets and expanded graphite are examples of such materials. Structural characteristics of these particles such as morphology and size have decisive influence on the final properties of bipolar plates. Furthermore, the volumetric fraction of the filler is of prime importance. There is plenty of information on individual aspects of specific composite bipolar plates in the literature. Notwithstanding, the analysis of structure-property relationship of these materials in a comprehensive source is not found. In this paper, relevant topics on the structural aspects of carbon based fillers and how they influence the final electrical performance of composite bipolar plates are discussed. It is intended that this document contribute to the development of new and maximized products to the PEM fuel cell industry.  相似文献
8.
Cadmium oxide thin films with different percentages of aluminum doping have been synthesized via radio frequency magnetron sputtering technique. Thin films were deposited on glass and silicon substrates with different percentages of aluminum at a substrate temperature of 573 K and pressure of 0.1 mbar in Ar+O2 atmosphere. The deposited films were characterized by studying their structural, electrical and optical properties. The X-ray diffraction pattern revealed good crystallinity with preferred (1 1 1) orientation in the films. Aluminum doping in CdO thin films were confirmed by X-ray photoelectron spectroscopic studies and actual doping percentages were also measured from it. The optical band gap was found to decrease first and then increase with increasing percentages of aluminum concentrations. The electrical conductivity was found to increase with increase of aluminum doping concentration up to 5% but for higher doping concentration (>5%) the conductivity was found to decrease.  相似文献
9.
Various combinations of commercially available gaseous and liquid fuels, burnt with air and preheated (1400K) air, and seeded with K2CO3, have been investigated analytically to arrive at an optimum combination that gives a reasonable electrical conductivity (10 mho/m) at minimum cost. This analysis has been carried out for gaseous and liquid fuels, separately, under Indian conditions. Variation of the electrical conductivity with the ratio of the mass of the fuels has also been obtained to make them usable in the cost structure of any country. Further, it has been shown that it is not only the C/H ratio but also the calorific value of the fuel that determines the electrical conductivity of the working fluid.  相似文献
10.
Damping of convection is key in the precise measurement of a diffusion coefficient in melt, and applying a static magnetic field to the melt is a promising method of realizing damping in electrically conducting melt such as a semiconductor and metal. Convection behavior in a melt with a low Grashoff number under a uniform static magnetic field was calculated on the basis of the finite element method. Using the results, the specimen geometry and the direction of the applied magnetic field in diffusion experiments with a diffusion-couple method were evaluated by the numerical simulation.  相似文献
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