Effect of plate aspect ratio on the recovery of deuterium from water-isotope mixture in flat-plate thermal diffusion columns with transverse sampling streams

The optimal plate aspect ratios for the best recovery of deuterium from water-isotope mixture in flat-plate thermal diffusion columns with transverse sampling streams have been determined. The maximum recovery and maximum production rate are achieved without changing the total expenditure, while the design with minimum plate surface area results in minimizing the total expense.     

虚拟企业中的知识扩散与技术创新

采用知识链方法对虚拟企业的技术和知识扩散与创新的方式和途径进行了初步探索，将虚拟企业中知识扩散方式分为传播扩散型、培养指导型和互动创造型三类模式；同时，认为信任机制是实现虚拟企业中成员企业知识特别是隐形知识的交流与共享的前提，是实现技术和知识创新的基础。     

Modelling of Al2O3 Powder Compaction with Hot Pressing in a Rigid Die

Computer modelling of hot pressing is provided. Kinetics are described for compaction during hot pressing in a rigid die, and the change in density distribution, irreversible solid phase strain accumulation, and equivalent stresses are studied by means of the finite element method. Shrinkage during the preparation of complex-shaped articles by hot pressing pure Al₂O₃ powder in a graphite die without a protective atmosphere and the physicomechanical properties of the finished article are studied. Calculated and experimental results agree satisfactorily.     

硬质合金与铁基复合材料热等静压扩散连接

以烧结结态硬质合金和粉末态铁基复合材料为连接对象，研究了两种材料的热等静压扩攻连接工艺，获得了直接连接接头和加镍作中间过渡层的间接连接接头，考察了接头的结合界面形貌，界面的元素扩散和界面结合强度。     

Cr/SiO_2界面还原反应研究

利用俄歇电子能谱研究了Cr／SiO2薄膜在热处理过程中的界面扩散反应机理、界面反应动力学过程及界面反应产物。研究结果表明，Cr／SiO2体系的界面还原反应主要是Cr与SiO2的反应，其还原反应产物是CrSix和Cr2O3物种。界面还原反应的速度与反应时间的平方根成正比，其界面还原反应过程受Cr向SiO2层的扩散过程所控制，界面还原反应的表观活化能为72．5kJ／mol（约0．75eV）。     

超高强度钢CF裂纹扩展的超载效应 Ⅰ．定量模型及预测

将Ｗｉｌｌｅｎｂｏｒｇ的超载残余应力场模型与裂尖形变动力学、裂尖表面析氢反应电化学动力学以及裂尖材料内部氢的扩散动力学和热力学相结合，建立了氢脆腐蚀疲劳裂纹扩展（ＣＦＣＧ）超载效应的定量描述模型，给出了超载对裂尖表面析氢电化学反应及裂尖氢扩展影响的一系列判据和表达式．用上述模型进行的预测表明，对于超高强度钢，当两次超载周次之间裂纹扩展长度ａｄ远小于超载塑性区尺寸ｒｐＯＬ与恒载塑性区尺寸ｒｐＣＬＡ之差，即ａｄ＜＜ｒｐＯＬ－ｒｐＣＬＡ时，ＣＦＣＧ会发生比空气疲劳还强烈的超载迟滞效应．而当ａｄ＞ｒｐＯＬ－ｒｐＣＬＡ时，可能会发生超载加速效应．这种预测在后文中由试验的宏观规律与断口特征得到充分验证．     

256比特的混沌分组密码

由于密码分析研究的进展及DES自身的弱点,原64比特的DES将不能作为数据加密的标准算法而长期存在。在原来工作的基础上,本文提出了256比特的分组密码方案。密码算法由基于混沌映射的数字滤波器构造。     

06NiCuCrMoNb钢高温加热时表层铜的行为

将06NiCuCrMoNb钢试样在不同的加热温度保温不同时间后，观察并分析试样表层的形貌和成分。结果表明，在一定条件下铜会扩散进入表层奥氏体晶界，得到沿奥氏体晶界分布的富铜相，并在热变形加工时导致热脆。试验得到了沿奥氏体晶界分布的富铜相与加热温度和保温时间的关系。     

多层气敏薄膜表面吸附及界面扩散的研究

制备了ＳｎＯ３／ＺｎＯ及ＺｎＯ／ＳｎＯ３多层结构的气敏薄膜，用能谱结合氩离子刻蚀的方法及Ｘ射线衍射法，对薄膜的表面吸附。膜间的相互与组成等进行了研究，结果表明：薄膜表面存在少量的吸附多层膜中锌的扩散远比锡一个模型，对吸附现象作了初步的解释，讨论了造成锌锡扩散的原因。     

Electrochemical properties of ultra-long,aligned, carbon nanotube array electrode in organic electrolyte

The electrochemical properties of an electrochemical double-layer capacitor electrode based on an ultra-long (500 μm), aligned, carbon nanotube array (ACNTA) in Et₄NPF₆/propylene carbonate electrolyte are examined. The specific capacitance of the ACNTA electrode in an organic electrolyte is 24.5 F g⁻¹, which is larger than that obtained in an aqueous electrolyte. The results of ac impedance measurements show that the ACNTA electrode gives a high power density and an excellent rate capability in an organic electrolyte. It is shown that the ACNTA electrode has a lower equivalent series resistance and a better rate capability than activated carbon electrode. This is due to the fact that ACNTA possesses a larger pore size and a more a regular pore structure. Both these features are conformed by scanning electron microscopic and nitrogen gas adsorption studies.