垂直加热管外自由降膜流的破断特性

在较宽液膜雷诺数和进口温度范围内对垂直加热管外自由降膜流破断特性进行了实验研究。应用热物理学相似分析的方法整理实验数据，给出新的破断准则数综合关系式，并与１９９３年发表的另一些作者的结果作了比较。实验参数的变化范围如下：ｔｉｎ＝２０～９０℃，最大液膜雷诺数Ｒｅ为１．２１×１０４，最大热流密度达１．３９×１０５ｗ／ｍ２。     

介绍一个化学工程与分析化学相结合的综合化学实验——超滤回收聚乙二醇

介绍超滤回收溶液中聚乙二醇的实验。采用Dragendorff试剂方法测定聚乙二醇浓度和截留率,研究操作条件对渗透速率的影响,探讨膜污染机理以及清洗方法,并根据实验中发现的问题,改进了Dragendorff测定方法。     

紫外－可见光谱法研究含Schiff碱基双分子膜的构象

测定了不同浓度、不同温度条件下含Ｓｃｈｉｆｆ碱基的单链两亲性化合物在Ｃ１６ＳＢＣ６Ｎ＋ＯＨ水溶液的电子吸收光谱。结果表明，两亲性分子在高温低浓度水溶液中处于较为分散状态，而在低温高浓度水溶液中呈聚集状态（双分子膜）。同时，通过量化计算比较，得出了不同聚集态时Ｓｃｈｉｆｆ碱基的构象（即Ｎ－苯环与Ｃ－苯环的扭转二面角）。     

In vivo mechanical study of helical cardiac pacing electrode interacting with canine myocardium

Cardiac pacing is a medical device to help human to overcome arrhythmia and to recover the regular beats of heart. A helical configuration of electrode tip is a new type of cardiac pacing lead distal tip. The helical electrode attaches itself to the desired site of heart by screwing its helical tip into the myocardium. In vivo experiments on anesthetized dogs were carried out to measure the acute interactions between helical electrode and myocardium during screw-in and pull-out processes. These data would be helpful for electrode tip design and electrode/myocardium adherence safety evaluation. They also provide reliability data for clinical site choice of human heart to implant and to fix the pacing lead. A special design of the helical tip using strain gauges is instrumented for the measurement of the screw-in and pull-out forces. We obtained the data of screw-in torques and pull-out forces for five different types of helical electrodes at nine designed sites on ten canine hearts. The results indicate that the screw-in torques increased steplike while the torque–time curves presente saw-tooth fashion. The maximum torque has a range of 0.3–1.9 N mm. Obvious differences are observed for different types of helical tips and for different test sites. Large pull-out forces are frequently obtained at epicardium of left ventricle and right ventricle lateral wall, and the forces obtained at right ventricle apex and outflow tract of right ventricle are normally small. The differences in pull-out forces are dictated by the geometrical configuration of helix and regional structures of heart muscle.     

Preparation of Ferrierite Zeolite Membranes in the Absence of Organic Structure-directing Agents

Zeolite membrane is an important category of inorganic membranes with many advantages such as thermal and chemical stability, high mechanical strength as well as the unique pore structure of molecular dimension. Up to now, many types of zeolite including …     

New Sorbent for Bilirubin Removal from Human Plasma： Albumin Immobilized Microporous Membranous PTFE Capillaries

In this study, we developed a tailored capillary sorbent for bilirubin removal. For immobilized bioligand, capillaries were grafted with epoxy groups using RIGP. The HSA immobilized capillaries has a high affinity adsorption capacity （71.2 mg bilirubin/g polymer） and a shorter adsorption equilibrium time （about 60 min）.     

高雷诺数下降液膜流动换热分析

本文分析了降液膜高雷诺数区域换热系数随液膜长度变化趋势,引出临界长度的概念。在较高雷诺数的湍流区,回流区的存在以及表面波的影响能有效地减少局部薄膜厚度并增加对流换热,流速的增加进一步强化换热,增加降膜整体传热系数。在高雷诺数区域,厚度形成的热阻超过回流的增强作用,而使换热削弱。液膜小于临界长度L换热系数随长度增长而增加,大于L换热系数随液膜增长而减小。     

TiN/TiB2异结构纳米多层膜的共格生长与力学性能

采用多靶磁控溅射法制备了一系列具有不同TiB₂调制层厚度的TiN/TiB_{2纳米多层膜.利用x射线衍射仪、高分辨电子显微镜和微力学探针研究了TiB2层厚变化对多层膜生长结构和力学性能的影响.结果表明，在fcc-TiN层(111)生长面的模板 作用下，原为非晶态的TiB2层在厚度小于2.9nm时形成hcp晶体态，并与fcc-TiN 形成共格外延生长；其界面共格关系为{111}TiN//{0001}TiB2，〈110〉TiN//〈1120〉TiB2.由于共格界面存在晶格失配 度，多层膜中形成拉、压交变的应力场，导致多层膜产生硬度和弹性模量升高的超硬效应， 最高硬度和弹性模量分别达到46.9GPa和465GPa.继续增加TiB2层的厚度，TiB2形成非晶态并破坏了与TiN层的共格外延生长，多层膜形成非晶TiN层和非晶TiB< sub>2层交替的调制结构，其硬度和弹性模量相应降低. 关键词： 2}纳米多层膜')" href="#">TiN/TiB₂纳米多层膜 共格生长 晶体化 力学性能     

磁盘润滑膜全氟聚醚的分子动力学模拟研究

纳米润滑膜全氟聚醚(perfluoropolyether，简称PFPE)在固体表面的结构和迁移特性对于计 算机磁盘磁头驱动系统的可靠性具有重要的作用. 采用基于粗粒珠簧模型的分子动力学模拟 方法，考察了不同壁面和端基极性对于PFPE膜静态特性（如分子构型、单体密度分布、端基 密度分布）以及动态特性（如自扩散系数）的影响. 静态特性的模拟结果表明，非极性PFPE 膜在壁面附近具有单层厚度为一个单体直径的层状结构，而极性PFPE膜则具有复杂的层状结 构. 动态特性的模拟结果表明，PFPE膜的扩散能力因壁面作用而增强并因端基极性作用而减 弱. 关键词： 全氟聚醚膜 分子动力学模拟 薄膜润滑 固液界面结构