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31.
Purification of cadmium by selective volatilization in vacuum in presence of oxide phase on its melt
Purification of cadmium in the presence of a thin (~0·001?mm) oxide layer on the surface of the molten metal was carried out using a simple system designed and fabricated locally. The analytical results revealed that the distillation through oxide layer gave better separation for Co, Ni, Cu, Zn, Ag, Sn, Hg and Tl, when compared to the distillation without oxide layer. This was attributed due to the impurity metal oxide phases formation on the surface of the molten metal. The influence of oxygen flow time on the distillation rate of cadmium was established. There was no excess oxygen (O) retained in the distillate after two consecutive vacuum distillations through oxide route. The experiments were conducted at the level of nearly 1·5?kg a batch to study the impurities behaviour due to upscaling. The detailed chemical analysis of 58 impurity elements in Cd in presence and absence of oxide layer was carried out by glow discharge mass spectrometry (GDMS). 相似文献
32.
33.
根据目前高压供电局计量方式的实际情况,本文对比分析了高供高计以及高供低计这两种高压供电方式的特点,并从经济性、维护的便捷性以及变损的计算等方面,明确了高供高计以及高供低计的适用范围,并为选择合理的高压供电计量方式提供指引. 相似文献
34.
The propagation of waves in incompressible beam-plasma systems is investigated on the basis of linear fluid equations. The pressure is assumed scalar and the incompressibility condition is chosen to illustrate a class of non-barotropic plasmas. The dispersion law For these linear waves is derived, and is generally discussed. The case of oblique propagation differs appreciably from results obtained for barotropic plasmas, mainly because compressional longitudinal waves are absent. Alfvén. waves in beam-plasma systems are then denned as low-frequency waves, with wave and drift frequencies small compared to gyrofrequencies. The Alfvén approximation of the dispersion law shows that the wave frequency at fixed wave-number is lower than if no streaming were applied. 相似文献
35.
Rapeta V. V. V. J. RAO T. C. CHONG L. S. TAN W. S. LAU N. LIM 《International Journal of Electronics》2013,100(9):1039-1050
Low temperature (LT)-grown GaAs and Al0.3Ga0.7As metal-insulator-n+-GaAs (MIN) diodes have been fabricated and their electrical properties analyzed. Studies were carried out to evaluate the interfacial quality of the LT layer and the underlying n+-GaAs layer using transient current spectroscopy (TCS) and capacitance-frequency (C-f) characterization. TCS studies on LT-GaAs revealed a high concentration of a continuum of states anda dominant electron trap with an activation energy of 0.52eV. In LT-Al0.3Ga0.7As, a shallow trap at 0.36eV and two deep level traps at 0.85eV and 1.12eV were observed. Frequency dispersion was observed to be less for LT-GaAs samples with an AlAs barrier layer than without an AlAs barrier layer. However, LT-Al0.3Ga0.7As MIN diodes displayed a smaller frequency dispersion than LT-GaAs MIN diodes. Upon further investigation into MISFET devices, it was found that LT-Al0.3Ga0.7As MISFET devices had better transconductance frequency dispersion characteristics than LT-GaAs MISFET devices did. 相似文献
36.
利用CO2激光脉冲对标准单模光纤(SMF)单向形成较小的几何形变,把部分基模能量耦合到光纤包层,制作了一种新型的在线型Michelson干涉传感器。理论分析了这种几何微扰激发的包层模特性,并利用芯模-包层模较大的热光系数差,把这种传感器应用于高温测量。实验结果表明,这种干涉传感器的温度灵敏度为0.093 7nm/℃,并且在800℃温度范围内具有良好的线性和重复性。这种制作简单、结构稳定、体积小和灵敏度高的全光纤在线型Michelson温度传感器将具有较大的潜在应用价值。 相似文献
37.
Outer layers of cotyledons of pigeonpea cultivar C 11 were successively scarified using a Tangential Abrasive Dehulling Device (TADD). Scarification for 0; 2, 4, 8, and 12 min resulted in the removal of 0, 6.7, 12.7, 25.3, and 36.9%, respectively, of powder fractions. The cotyledons and powder fractions at each level of scarification were analyzed for chemical composition, including minerals and trace elements, protein fractions, amino acid composition, and trypsin inhibitor acitivity (TIA). Protein, soluble sugars and ash of the dhal fraction (scarified cotyledons) decreased with increasing scarification time, while starch content increased. Considerable amounts of calcium (about 20%) and iron (about 30%) were removed by scarification for 4 min, but the process did not adversely affect protein quality in terms of amino acids. Trypsin inhibitors were not removed substantially by scarification. 相似文献
38.
Knowledge graph is a useful resources and tools for describing entities and relationships in natural language processing tasks.However,the existing knowledge graph are incomplete.Therefore,knowledge graph completion technology has become a research hotspot in the field of artificial intelligence,but the traditional knowledge graph embedding method does not fully take into account the role of logic rules and the effect of false negative samples on knowledge embedding.Based on the logic rules of knowledge and the role of adversarial learning in knowledge embedding,we proposes a model to improve the completion of knowledge graph:soft Rules and graph adversarial learning (RUGA).Firstly,the traditional knowledge graph embedding model is trained as generator and discriminator by using adversarial learning method,and high-quality negative samples are obtained.Then these negative samples and the existing positive samples together constitute the label triple in the injection rule model.The whole model will benefit from both high-quality samples and logical rules.In addition,we evaluated the performance of link prediction task and triple classification task on Freebase and Yago datasets respectively.Finally,the experimental results show that the model can effectively improve the effect of knowledge graph completion. 相似文献
39.
MATLAB是一款高性能的科学与工程计算软件,具有强大的数值计算和分析能力,但其对硬件的访问能力较弱。在MATLAB环境中实现对硬件资源的直接访问可以极大的方便对数据的处理及算法的验证,基于这种目的提出一种扩展MATLAB访问硬件的方法,通过MATLAB外部函数接口调用第三方器件商提供的动态链接库导出函数,在MATLAB平台下实现对一般硬件的访问,并具体介绍了该方法在气压高度计原型系统设计中的应用。该方法简化了MATLAB与硬件的数据交互,对于原型系统设计和算法的验证提供了一种有效的手段。 相似文献
40.
The varying population density leads to imbalanced utilization rate of satellites. To ensure an intelligent engineering of traffic over satellite networks, a distributed routing scheme for single-layered satellite network, load balancing routing protocol based on mobile agent (LBRP-MA) is proposed. For LBRP-MA, mobile agents explore route by migrating autonomously. Upon arriving at destination, mobile agents migrate back. On each intermediate satellite, mobile agents evaluate path cost considering satellite geographical position as well as inter-satellite link (ISL) cost, and finally take ISL congestion index into account to update routing tables. Through simulations on the Courier-like constellation, the proposed approach is shown to achieve guaranteed end-to-end delay bound and decrease packet loss ratio with better throughput, which is especially suitable for data transferring in case of high traffic load. Moreover, results of the complexity analysis demonstrate that LBRP-MA can have low onboard signaling, storage and computation requirements. Furthermore, issues of LBRP-MA such as ISL congestion index and cost modification factor are discussed. 相似文献