国内外聚乙烯管材树脂生产现状

介绍国内外聚乙烯管材料的开发和生产情况,以及聚乙烯管材树脂的主要生产厂家。     

Operational aspects of adsorption air‐conditioner used in diesel locomotive

A locomotive cabin adsorption air‐conditioner has been equipped in #DF4B‐2369 locomotive; and has been successfully run for 2 years. It is powered by waste heat from the exhaust of the diesel engine. The influence on heat transfer is described by the equivalent heat transfer coefficient or thermal resistance of components inside the adsorber. The variation of adsorption capacity is expressed by a non‐equilibrium adsorption function. The dynamic heat transfer process of adsorption air‐conditioning system is treated with the lumped parameter method. Some typical running experimental results are present. The diesel engine rotating speed and locomotive speed influenced on the refrigeration system are discussed. The maximum mean refrigeration power is regarded as an objective function. Based on experiments and theoretical analysis, the running characteristics of the air‐conditioning system are optimized. Some techniques of performance improvement are suggested as well. Copyright © 2006 John Wiley & Sons, Ltd.     

T-ZnO晶须增强环氧树脂复合材料的力学行为

研究了以四脚状氧化锌（T-ZnO）晶须为增强剂，环氧树脂复合材料的力学行为。结果表明，由具有三维空间结构的T-ZnO晶须为增强剂所制备的环氧树脂复合材料具有各向同性的力学性能，T-ZnO晶须填加质量分数为6%时，就可使材料的力学性能改善；拉伸强度提高到169%，拉伸功几乎提高了100%，冲击强度提高到300%，抗弯的断裂功提高到158%，而压缩强度略有下降。     

加快塑料技术中心建设提高新产品开发水平

对中国石油化工集团公司(简称中国石化)合成树脂生产及加工应用技术的现状进行了分析，指出中国石化应加快建设塑料加工应用技术中心，为塑料产品的加工用户提供高技术水平和快捷周到的技术服务，在合成树脂新产品开发和产品结构调整中发挥积极作用，以提高合成树脂产品的市场竞争力。     

Volumetric Change and Surface Properties of Temperature-Sensitive Polyvinylalcohol (PVA) Hydrogel

Polyvinylalcohol (PVA) polymer gel is a temperature sensitive polymeric gel, with a critical transition temperature (with H₂O) of 310 K. At higher than 310 K, this temperature sensitive polymer gel shrinks because of discharging water, whereas at lower temperatures, the gel swelled because of absorbing water. The reversibility of the gel's volume change was confirmed by temperature swing. The adsorption behavior of an organic compound onto the PVA polymer gel in water was tested at various temperatures. The amount of adsorbed organic compound increased remarkably at temperatures higher than about 310 K. Then, it was confirmed that the organic compound in PVA polymer gel could be reversibly adsorbed and desorbed by a temperature change between 293 and 323 K. The mechanism of adsorption of the organic compound onto the PVA polymer gel could be explained by hydration and dehydration of polymer gel.     

煤层气利用新方案

在介绍煤层气的常规利用方案的基础上，提出了两种利用煤层气的新方案：一是采用变压吸附技术，纯化瓦斯气，将低浓度瓦斯气浓缩为高浓度瓦斯气，加压后成为CNG，用作CNG气源或较远距离城市的天然气气源；二是在第一种方案的基础上，将高浓度瓦斯气全部采用深冷法加以液化，生产LNG，并将LNG运送至更远距离用作LNG加气站、CNG加气站气源。最后还以松藻煤电公司为例，作了新方案的工程预算     

天然气吸附储存脱附过程的动态模拟

通过热动力学计算,认识了脱附过程当中储罐内温度剖面分布的典型特征:储罐轴心处的温度下降幅度最大。分析了脱附过程当中储罐壁的热交换、吸附剂的导热系数以及储罐内的初始压力对储罐内的温度剖面的影响。结论是加强储罐外壁的热交换、增大吸附剂的导热系数皆能改善吸附储罐内的温度剖面。     

Inhibition effect of carbon dioxide on the oxidation of hydrogen over a platinum foil catalyst

This paper investigates the catalytic ignition of the H₂/O₂/CO₂ mixture on platinum in a stagnation flow at atmospheric pressure experimentally and numerically. We measure the ignition temperatures of the gas mixtures flowing towards resistively heated platinum with various composition ratios and various diluent gases of N₂, Ar and CO₂. Compared with N₂ or Ar, the CO₂ dilution shows higher ignition temperature by about 50 K, even at the same composition ratio. The ignition temperature increase is proportional to the dilution ratio. Through the numerical simulation, it is illustrated that higher ignition temperature is caused by the adsorption of CO₂ and following dissociation on platinum surface, which was to date considered negligible in catalytic combustion.     

Chemische Zusammensetzung und Mikrostruktur polymerabgeleiteter Gläser und Keramiken im System Si–C–O. Teil 2: Charakterisierung der Gefügeausbildung mittels hochauflösender Durchstrahlungselektronenmikroskopie und Feinbereichsbeugung

Chemical Composition and Microstructure of Polymer‐Derived Glasses and Ceramics in the Si–C–O System. Part 2: Characterization of microstructure formation by means of high‐resolution transmission electron microscopy and selected area diffraction Liquid or solid silicone resins represent the economically most interesting class of organic precursors for the pyrolytic production of glass and ceramics materials on silicon basis. As dense, dimensionally stable components can be cost‐effectively achieved by admixing reactive filler powders, chemical composition and microstructure development of the polymer‐derived residues must be exactly known during thermal decomposition. Thus, in the present work, glasses and ceramics produced by pyrolysis of the model precursor polymethylsiloxane at temperatures from 525 to 1550 °C are investigated. In part 1, by means of analytical electron microscopy, the bonding state of silicon was determined on a nanometre scale and the phase separation of the metastable Si–C–O matrix into SiO₂, C and SiC was proved. The in‐situ crystallization could be considerably accelerated by adding fine‐grained powder of inert fillers, such as Al₂O₃ or SiC, which permits effective process control. In part 2, the microstructure is characterized by high‐resolution transmission electron microscopy and selected area diffraction. Turbostratic carbon and cubic β‐SiC precipitate as crystallization products. Theses phases are embedded in an amorphous matrix. Inert fillers reduce the crystallization temperature by several hundred °C. In this case, the polymer‐derived Si–C–O material acts as a binding agent between the powder particles. Reaction layer formation does not occur. On the investigated pyrolysis conditions, no crystallization of SiO₂ was observed.     

改性双马来酰亚胺的研究

本文研究了双马来酰亚胺与烯丙基化合物形成的改性树脂体系的固化和热性能，讨论了单体配比、增韧剂、催化剂对性能的影响。