泡沫铝的动态压缩性能和吸能性研究

通过测量泡沫铝在动态和准静态压缩条件下的应力 -应变曲线 ,研究了泡沫铝的准静态和动态压缩行为以及不同应变条件下的吸能性 ,并对其应变率效应进行了分析。结果表明 ,在高应变速率和准静态压缩下 ,泡沫铝的σ -ε曲线均表现出弹性变形段、平缓段和密实段三阶段特征 ;泡沫铝的压缩性能具有明显的应变速率敏感性 ,随应变速率的提高 ,流动应力上升 ,吸能性升高     

曲率圆弧段代替切线段的数值计算方法

为了确保安全,核工业和其它一些工业要求某些参数的计算值只能取正的相对误差且不大于5×10-3,这是它们对数值计算的基本要求.例如,反应堆带功率运行时,功率增长总是随时间上升,功率曲线是向下凹的.传统的龙格-库塔法计算值总是小于真实值,并且随着时间的增加,计算值越来越小于真实值.按计算值分析,反应堆是安全的,但实际上反应堆是不安全的.这对反应堆的安全极为不利.为此,本文开拓了一个全新的数值计算方法.与龙格-库塔法相比,该方法计算工作量小,与预测一校正法相比,该方法没有启动问题.更值得指出的是计算值高于真实值,这样,反应堆计算结果总是偏于安全的.     

基桩反射波法动测曲线的数值模拟与特征分析

采用美国PDI公司开发的PDI-S软件,对不同缺陷基桩的反射波法低应变动测曲线进行数值模拟,对动测曲线的特征进行归纳与总结,以便在解释反射波法曲线时作为参考与借鉴,提高基桩质量检测的可靠度。     

同心筒发射中旁泄流影响的数值研究

同心筒是一种先进的新型的舰载导弹垂直发射装置。文中采用动网格技术模拟了导弹在同心式发射筒内发射的瞬态过程。探讨了发射过程中旁泄流的产生与消失原因。通过设计内外筒的合理大小可以有效减弱旁泄流的影响。通过大量的数值实验,给出了避免外筒发生雍塞的代数关系式。     

Validity of dynamic electrochemical impedance spectra of some amine corrosion inhibitors in petroleum/water corrosive mixtures by Kramers-Kronig transformation

In our previous works, the corrosion inhibition properties of propylamine (PA), iso-propylamine (i-PA), butylamine (BA), tert-butylamine (t-BA), hexylamine (HA), ethylenediamine (EDA), diethanolamine (DEA), 3-amino-1-propanol (3-AP), 2-dimethylethanolamine (2-DEA), cyclohexylamine (CHA), N-methylcyclohexylamine (N-MCA) and dicyclohexylamine (DCHA) have been investigated by means of electrochemical impedance spectroscopy (EIS) with a carbon steel rotating disc electrode in some petroleum/water corrosive mixtures containing acetic acid and NaCl at 25 °C. In this work, the Kramers-Kronig transformations (KKTs) were applied to evaluate the validity of the impedance data of these amine compounds in hydrodynamic condition. The results obtained showed that experimental impedance data did not satisfy in K-K relations completely viz. indicated some errors. These errors were related to stray capacitances, external transmission line effects, pits formation and change in interface during data acquisition at high and low frequencies regions. In addition, the selection of a suitable equivalent circuit strongly emphasized to better interpret of EIS data which in turn cause better resulted KKTs spectra. With considering obtained transformations, more effective inhibitor was selected with regard to its charge transfer resistance, the corrosion capacitance and well satisfying in K-K relations.     

龙开口水电站溢流坝段动力模型破坏试验研究

采用仿真混凝土材料研究了龙开口水电站溢流坝段在不同因素影响下的动力破坏特征,并通过对6个模型试验结果的分析探讨了溢流坝段的动力破坏机理。试验中考虑了坝体-库水的动力相互作用以及横河向地震动对大坝破坏的影响,采用规范谱波和场地谱波两种地震动激励进行模型超载破坏分析。试验结果为工程设计和评价溢流坝段的抗震性能提供依据。     

全密封变压器用波纹油箱的波纹高计算

介绍了全密封变压器所用的液纹油相的波纹筋高的计算方法，并用试验进行了验证。     

利用5A284型铣齿机加工转盘螺旋锥齿轮探讨

利用引进设备5A284苏联铣齿机加工石油钻机转盘螺旋锥齿轮，建立计算程序并进行调整计算，详述了遇到的问题及解决方法，使所加工的锥齿轮质量良好。     

Viscoelasticity of oxidized starch/low methoxy pectin mixtures in the presence of glucose syrup

The structural properties of mixtures of pectin, oxidized starch and glucose syrup were investigated using small deformation dynamic oscillation. In the absence of added calcium, preparations of low methoxy pectin with glucose syrup formed viscous solutions, which remained crystal-free at subzero temperatures. Samples of oxidized starch and glucose syrup, on the other hand, exhibited solid-like behaviour because of the crystalline nature of the amylose-like helices. Mixtures of the two polysaccharides with the co-solute clearly showed phase inversion from liquid to solid-like behaviour with increasing amounts of starch in the formulation. The transformation was reflected in the textural properties of samples, which varied from thick solutions to firm gels. The viscoelasticity of the system was modified further by the introduction of high methoxy pectin. Preparations of high methoxy pectin and glucose syrup formed rubbery gels whose amorphous nature underwent a glass transition during cooling.     

车载制氧机加装预冷装置的研究与实现

航空兵部队地面保障装备之一的车载移动式制氧机，采用封闭循环水冷却，由于受到使用条件的限制，多数情况下冷却效果不尽理想，加装蒸汽压缩预冷装置，即可较好地了和低冷却系统温度，提高制冷量和整机使用寿命，又可满足整车机动性，动力等技术要求。