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排序方式: 共有316条查询结果,搜索用时 15 毫秒
281.
The CaO doped 10NiO-NiFe2O4 composite ceramics were prepared by the cold isostatic pressing-sintering process, and the effects of CaO content on the phase composition, mechanical property and thermal shock resistance of 10NiO-NiFe2O4 composite ceramics were studied. The results show that the samples mainly consist of NiO and NiFe2O4 when content of CaO is less than 4%(mass fraction), bending strength increases obviously by CaO doping. Bending strength of the samples doped with 2% CaO is above 185 MPa, but that of the samples without CaO is only 60 MPa. Fracture toughness is improved obviously by CaO doping, the samples doped with 2% CaO have the maximum fracture toughness of 2.12 MPa·m^1/2, which is about two times of that of the undoped ceramics. CaO doping is bad to thermal shock resistance of 10NiO-NiFe2O4 composite ceramics. 相似文献
282.
Current distribution in a drained aluminum reduction cell is critical due to its influence on the current efficiency, electrolysis stability, anodes and cathodes integrity. A finite element model was developed to simulate the electric field in a 75 kA drained aluminum reduction cell. The current distribution and influences of the cathode inclination angle and anode-cathode distance (ACD) were studied. The results show that relatively large horizontal current density appears in the aluminum film, and the max... 相似文献
283.
Digital characterization and mathematic model of sodium penetration into cathode material for aluminum electrolysis 总被引:2,自引:1,他引:1
The sodium expansion curves of semi-graphitic cathode and TiB2/C composite cathode with different TiB2 contents were measured with the improved Rapoport-Samoilenko apparatus. The mathematic model of the sodium expansion was
deduced on the basis of the experimental results. The sodium expansion parameter (a) and penetration rate factor (Q), were introduced into the model. The model was validated with the experimental sodium expansion curves self-measured and
reported. The results show that the variation tendency of the sodium expansion parameter (a) and penetration rate factor (Q) is consistent with that of the experimental curves. The model is capable of not only conveniently judging the cathode quality,
but also favorably establishing a unified standard of the resistance to sodium penetration of cathode.
Foundation item: Project(2005CB623703) supported by the Major State Basic Research and Development Program of China; Project(2008AA030502)
supported by the National High-Tech Research and Development Program of China; Project(GUIKEJI0639032) supported by the Science
Fund Project of Guangxi Province, China 相似文献
284.
Electrochemical behavior of wound supercapacitors with propylene carbonate and acetonitrile based nonaqueous electrolytes 总被引:1,自引:0,他引:1
The activated carbon wound supercapacitors with TEABF4/propylene carbonate (PC) and TEABF4/acetonitrile (AN) electrolytes were prepared. The effects of the electrolyte and temperature on the capacitance behavior
were investigated by cyclic voltammetry (CV) and constant current charge-discharge. Compared with the PC-based supercapacitor,
the AN-based supercapacitor has higher capacitance and lower equivalent serial resistance (R
ES) at discharge currents ranging from 5 to 1 000 mA and 25 °C. Moreover, temperature effects are more prominent for PC-based
supercapacitor than for AN-based supercapacitor. When the measurement temperature ranges from 60 °C to −40 °C the capacitance
changes from 5.1 to 2.5 F and R
ES changes from 135 to 876 mΩ for the PC-based supercapacior, while the AN-based supercapacitor shows less change in capacitance
and R
ES. Thus AN-based supercapacitor exhibits excellent power characteristics and temperature property.
Foundation item: Project(20803095) supported by the National Natural Science Foundation of China; Project(2008AA03Z207) supported by the National
High Technology Research and Development Program of China 相似文献
285.
The precursor of ammonium aluminum carbonate hydroxide was synthesized by using aluminum sulfate (Al2 (SO4)3 ) and ammonium carbonate((NH4 )2CO3 ). The effects of α-Al2 O3 seeds and mixture composed of α- Al2O3 and ammonium nitrate, as well as multiplex catalysts (AT) on phase transformation of alumina in sintering process were investigated respectively. The results show that the α-Al2 O3 seeds and the mixture of α-Al2 O3 and ammonium nitrate can lower the phase transformation temperature of α-Al2O3 to different extents while the particles obtained agglomerate heavily. AT has great potential synergistic effects on the phase transformation of alumina and reduces the phase transformation temperature of α-Al2O3 and the trends of necking-formation between particles. Therefore the dispersion of powder particles is improved significantly. 相似文献
286.
1 INTRODUCTIONThere are many disadvantages in the presentaluminumelectrolysis with carbon anode ,such assevere energy consumption,carbon wasting,envi-ronmental pollution and so on.Inert electrode sys-tem can overcome these disadvantages[1 3]. Re-cently ,the researches of the inert anode materialshave mainly been concentrated on alloys[4]and cer-met materials[5 ,6]. NiFe2O4based cermets , whichpossess not only high electrical conductivity ofmetal but also good corrosion resistance of cera… 相似文献
287.
1 INTRODUCTIONThe use of inert or non-consumable anodes forreplacement of consumable carbon anodes in Hall-H啨roult electrolysis cells for the production of alu-minum has been a technical and commercial goalfor many decades .In the present process ,consumable carbon an-odes are used,andthe anode product is CO2. Withaninert anode ,the cell reaction will be :Al2O3=2Al +23O2(1)The basic requirements for aninert anode are :1) to exhibit a lowcorrosion rate in the high tem-perature melts an… 相似文献
288.
Influence of KOH activation techniques on pore structure and electrochemical property of carbon electrode materials 总被引:2,自引:3,他引:2
1 INTRODUCTIONSupercapacitor is a kind of newenergy storagedevice , which can fill the gap between the conven-tional capacitor and the battery[1 ,2]. Supercapa-ciors are nowutilizedin many fields ,such as spaceindustry ,national defense ,warindustry ,electricalvehicle , wireless communication, and consume e-lectronics .It is well known that the electrode ma-terial is the key factor to determine the perform-ance of supercapacitor . At present ,the activatedcarbonis the main marketed availa… 相似文献
289.
李劼 《现代测量与实验室管理》2006,14(3):35-35,34
本文介绍了电话机通话状态交流阻抗对应的稳定平衡回损和回声平衡回损测量结果不确定度评定,分析了不确定度主要来源,计算和评定了相应的标准不确定度、合成不确定度和扩展不确定度. 相似文献
290.