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101.
赵家巧  刘时杰 《贵金属》1995,16(4):19-24
用三烷基胺(N235)萃取分离铂,考察了稀释剂、改质剂浓度、料液酸度对分配系数的影响,从复杂的工业料液中,用N235萃取、洗涤、反萃、再生及精炼铂的工艺技术。  相似文献   
102.
Some cobalt antimonides have been prepared and studied as the candidate anode materials for lithium ion batter-ies. Reversible capacities of 424,423 and 546 mA·h·g-1 were measured at the first cycle for as-solidified CoSb2, CoSb3 and annealed CoSb3 respectively. A low lithium ions diffusion coefficient in the order of 10-16 m2·s-1 was estimated from the coulometric titration measurements in the annealed CoSb3 electrode. It was found that the electrochemical properties of fine powders are significantly better than coarse powders. However the SEM picture shows that the nano-sized CoSb3 powders gathered to larger granules, which worsens somewhat the capacity retention of the nano-sized materials, although the volume capacities of the annealed and ball milled CoSb3 remain near twice of that of graphite after 50 cycles.  相似文献   
103.
Temperature stability and toughness of magnets are very important properties especially for application in motor. In this paper, it is found that temperature stability and toughness of magnets are improved when Fe is substituted with Co andheavy rare earth is substituted for Nd in part and suitable rich B grain-boundary phase is added. In addition, heavy rare earth substitution decreases the remanence temperature coefficient greatly, but has a little effect on Curie temperature of the magnets, which is beneficial to Nd-Fe-B magnets for the application in motor.  相似文献   
104.
Easy and hard magnetization curves of Nd_2Co_(14)B compound have been measured withextracting-sample-magnetometer(μ_0H_(max)=6T)at 10~300 K.Magnetic anisotropy constants K_1 and K_2have been determined by fitting the hard magnetization curves,in which only K_1 ,K_2 and misalignment anglehave been taken as fitting parameters.The values of K_1 and K_2 at 4.2 K were derived by extrapolation.Anisotropy coefficients,x_2~° and x_4~°were derived from the anisotropy constants.The anisotropy constant K_2increases rapidly with increasing temperature when TT_(sr).The temperature depen-dence of the magnetic anisotropy coefficient x_2~° was fitted with the formula.The anisotropy coefficients x_2~°can be well described by the tenth-power law from 4.2 K to T_(sr)and by the sixth-power law from T_(sr_ to 300 K.  相似文献   
105.
赵品  崔明勋 《物理测试》1995,(1):10-12,9
将正火40Cr钢样在不同温度下进行不同时间的气体渗氮,对其横断面进行波谱分析,发现渗氮前沿附近自始至终存在着典型的贫碳区,其两侧为富碳区,透射电镜分析结果表明,碳原子的重新分布包括碳化物的回溶、碳的扩散及碳化物长大三个过程。  相似文献   
106.
机器工作可靠度与机器的固有可靠度和使用可靠度密切相关。设备使用厂家通过对机器偶发故障期使用可靠度的研究,采取有效对策来保证和提高机器工作可靠度,是提高企业效益的途径之一。本文针对压铸机,进行了故障规律分析,介绍了偶发故障期可靠度的计量公式,提供了各故障期的经验数据,详述了应用可靠性技术的基础工作范围和内容,叙述了应用效果  相似文献   
107.
研究了Sr元素(加入量分别为0.03%、0.06%、0.09%、0.12%和0.18%)对含Fe量为1.2%的ZL102合金的组织和性能的影响。研究发现,随着Sr元素的加入,合金中粗大的针状Fe相开始出现断裂分叉现象,同时针状Fe相的长度也随Sr元素加入量的增加而减小,但Sr对Fe相的针状形貌没有明显改变。随着Sr元素加入量逐渐增加,合金的抗拉强度和伸长率均呈现出先增后减的变化趋势。当Sr元素加入量达到0.12%时,合金材料的综合力学性能最佳。  相似文献   
108.
This article discusses the cooling strategies for cryogenic machining from a materials viewpoint. It is argued that, because different materials respond to temperature and machining processes differently, different cooling strategies are needed to improve the machinabilities of materials by cryogenic machining. In this work, five workpiece materials such as AISI1010 low-carbon steel, AISI1070 high-carbon steel, AISIE52100 bearing steel, titanium alloy Ti-6Al-4V, and cast aluminum alloy A390 were studied experimentally at various temperatures. Based on the experimental results of the cryogenic properties of the materials and their known machining characteristics, the cooling strategies for cryogenic machining of these materials were analyzed.  相似文献   
109.
BREAKAGE MECHANISM OF TUNGSTEN BASED ALLOY BLOCK FOR ELECTRO-HEAT UPSETTING   总被引:3,自引:0,他引:3  
The breakage mechanism of W-Ni-Fe alloy in the process of electro-heat upsetting studied both theoretically and experimetnally, and also the behaviors of crack formation and propagation were analysed. Alloy suffers from corrosion and thermal-mechanical fatigue mutual function. Simultaneously, the practical ways to improve the anvil life was discussed.  相似文献   
110.
Using potassium permanganate and acetic manganese as the reactants, amorphous manganese oxide was prepared with mechanochemical method. XRD was used for microstructure characterization, while cyclic voltammetry and constant current charge-discharge were used for electrochemical performance testing. The positive electrode (PE) and negative electrode (NE) were investigated respectively in amorphous manganese oxide supercapacitor, aiming to find their different performances in charging-discharging. The results show that the crystalline structure is destroyed in both the PE and NE material during charge-discharge process. Thereinto, the NE suffers a bit more seriously. When cycling, the PE potential scope diminishes while the NE potential scope enlarges. The increased inner resistance makes the NE curves almost bended to be a right angle, but not the PE curves. The cell's equivalent series resistance (ESR) is more dependent on the NE, and the capacitance is mainly determined by the rapid descent of the NE potential range. The capacitances of the NE are highly rate-dependent, decreasing from 121.3 to 53.1 F/g, by 56.2%, over the range of 5-25 mV/s. However, the PE appears to be weakly dependent and its capacitance is only dropped by 22.1%.  相似文献   
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