TiNi和TiNiCu记忆合金可逆应变能与温度的经验关系

在实验基础上研究了Ti_(50)Ni_(50),Ti_(50)Ni_(45)Cu_2)和Ti_(50)Ni_(45)Cu_5的可逆形状记忆效应,得到可逆应变能U_r与温度的经验关系: U_r=U_0[1-exp(-mT_R~N)] 式中,n是形状一温度敏感指数,m是与材料特性有关的常数.移植Johnson-Mehl-Avrami描述相变-时间关系的唯象方法,得到与可逆形状记忆效应相伴随的热弹性马氏体相变与温度的半定量关系,且与上述经验关系对应.     

机械结构优化研究与实践

文章介绍了机械结构优化设计的基本概念。作者论述了如何基于有限元技术建立结构优化数学模型，如何进行灵敏度分析和优化分析，以及如何对优化解进行取舍。最后作者通过实例对某典型结构件的主要尺寸参数进行了以质量为目标函数的评估和优化。在确保该零件具有足够强度和刚度的前提下，实现了其重量的较大幅度降低。     

ZMl Mg合金的表面滚压强化SCIEI

研究了表面滚压对ＺＭ１Ｍｇ合金疲劳强度和疲劳缺口敏感度的影响。结果表明，滚压可使其光滑疲劳极限提高５７％，缺口疲劳极限提高２００％，大大降低疲劳缺口敏感度，使ｑ出现负值。ｈｃｐ的ＺＭ１Ｍｇ合金滚压时以滑移和孪生方式变形和形变强化，引入高的残余压应力，有利于提高缺口疲劳极限和降低疲劳缺口敏感度。     

涡流检测技术在宝钢热轧轧辊上的应用

介绍了轧辊涡流检测仪的工作要求、设备组成和使用方法,指出对轧辊进行涡流检测可防止爆辊,减少轧辊磨削量。     

LiFePO4基正极材料容量的温度敏感特性及交流阻抗谱研究

采用原位碳包覆法制备了锂离子二次电池用LiFePO4／C复合正极材料。考察了环境温度对LiFePO4/C电池容量的影响，得到容量与绝对温度之间符合Arrhenius关系。运用交流阻抗谱分析了温度与电池电化学特性的关系，并对电极基于电荷和质量传递控制过程给出了一种新的模拟等效电路，通过Zview拟合软件得到了各个模拟元件的数值及变化趋势，从而定量地解释LiFePO4／C复合电极容量与温度的关系。     

Effect of temperature on mechanical behavior of AZ31 magnesium alloy

Strain rate sensitivity and tension/compression asymmetry of AZ31 magnesium alloy at different temperatures and strainrates were investigated.Both of mechanical behaviors are temperature dependent.Strain rate sensitivity increases with increasingtemperature.Thermally activated slip is the source of strain rate sensitivity.At the temperature below or near 373 K,strain ratesensitivity is very little.Tension/compression asymmetry in yielding decreases with increasing temperature.Twinning is the reasonof tension/compression asymmetry.At the temperature above or near 573 K,the material shows little tension/compressionasymmetry of the flow stress.     

东河储层损害机理分析

钻井液和酸化体系与储层流体不配伍是造成油层损害的主要原因。东河砂岩含有不同类型敏感性矿物,利用常规钻井液和酸化技术难以达到保护储层的目的。本文在分析东河储层敏感性损害机理前提下,提出保护油层的2项措施。     

PH敏感性水凝胶的分子热力学模型

本工作是在非离子凝胶的分子热力学模型基础，引入Ｄｏｎｎａｎ平衡项和大分子离子链的静电排斥项对凝胶自由能的贡献，建立了一个新的离子凝胶的分子热力学模型。该模型在解释离子凝胶的ＰＨ敏感性及其各种影响因素，以及预测ＰＨ溶胀曲线方面都取得了较好的效果。     

Platinum particle size effect on the oxidative dehydrogenation of aqueous ethanol

The effect of the platinum particle size was investigated for the catalytic oxidative dehydrogenation of aqueous ethanol to ethanal at a temperature of 303 K, an ethanol concentration of 260 mol m^–3, a partial oxygen pressure 60 kPa, a pH of 9, and an ethanal and ethanoate concentration of 20 mol m^–3. A particle size effect on the turnover frequency was observed but only for particle sizes smaller than 2 nm. Hence, the reaction shows a limited structure sensitivity.     

Hydrogen evolution during the oxidation of formaldehyde on Au:: The influence of single crystal structure and Tl-upd

Hydrogen evolution during formaldehyde oxidation in alkaline solution has been monitored by Differential Electrochemical Mass Spectrometry on Au(111) and polycrystalline gold. The current efficiency for hydrogen evolution increases with higher concentration and is in the same range on both, polycrystalline Au and Au(111) electrode. The onset potentials and half-wave potentials are higher on Au(111). Reaction orders for the faradaic current on the bare gold electrodes have been determined as 0.21 for higher and 0.76 for lower concentrations. Reaction orders for hydrogen evolution during formaldehyde oxidation are 1.4 times higher in each case. Tafel slopes in the range of 140-160 mV are found. This signifies that the first reaction step involving the formation of adsorbed hydrogen is largely determining the overall reaction rate. In the presence of thallium adlayers hydrogen evolution from formaldehyde oxidation is largely suppressed. On the thallium modified polycrystalline Au, formaldehyde oxidation is shifted for 100 mV to higher potentials where Tl is partially desorbed and hydroxide is coadsorbed on the modified surface. On thallium modified Au(111), a similar process takes place, but in the same potential region as the onset of formaldehyde oxidation on the bare surface and therefore the formaldehyde oxidation is only slightly shifted. Tafel slopes are decreased to 80 mV/dec in the presence of thallium. In the presence of adsorbed thallium, the first reaction step is in equilibrium, the coverage with adsorbed hydrogen is smaller and its recombination to H₂ is largely suppressed.