Performance of natural‐fiber–plastic composites under stress for outdoor applications: Effect of moisture,temperature, and ultraviolet light exposure

The effects of moisture, temperature, and ultraviolet (UV) light on performance of natural‐fiber–plastic composites (NFPC) were assessed. We conducted short‐term tests in the laboratory and long‐term tests under natural exposure and measured changes in mechanical properties and color in samples of the composite. Chemical changes of the composite's materials were measured by X‐ray photoelectron spectroscopy to elucidate the mechanisms of chemical transformations on the material surface. Relative humidity highly affected the modulus of rupture (MOR) and the modulus of elasticity (MOE), and had a greater effect than temperature and UV exposure on performance of the composite. The lightness of the composite was increased by the UV effect in the short‐ and the long‐term tests. The X‐ray photoelectron spectroscopy (XPS) analysis suggested that the composite was protected by the UV absorber. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 2570–2577, 2006     

太钢不锈冷轧工程防腐蚀施工技术

防腐蚀施工工艺掌握的好坏，直接影响到工程投入生产后的使用寿命，为保证工程质量，以太钢不锈冷轧改造工程冷线防腐为例，对其常发生的质量通病进行认真分析，总结出一套行之有效的施工技术。     

Analytical pyrolysis as a tool for the study of plastic coals

The technique of analytical pyrolysis has been used to characterize 40 similar mid-rank western Kentucky coals of widely differing ASTM Gieseler plasticity. Certain pyrolysis/g.c. variables were shown to correlate well with both ASTM Gieseler and isothermal plasticity. Highly plastic coals were shown to exhibit certain characteristic peaks in the 450 °C pyrogram which were absent in the pyrogram of the non-plastic coals. Two coals, representing the two extremes in plasticity, were selected for further study. After extraction with solvents such as DMF the characteristic peaks were absent in the 450 °C pyrogram of the extraction residue of the highly plastic coal. These peaks were also shown to decrease with increasing severity of air oxidation of the plastic coal. This technique appears to be a useful tool for the analysis of mid-rank plastic coals and supports the view that the substances contained in the bitumen fraction of these coals are involved in the development of the plastic state.     

聚乙烯丙纶复合防水卷材的特点及其应用

介绍了聚乙烯丙纶复合防水卷材的产品结构特点和性能特点、防水系统结构特点和配套材料、应用拼接技术以及产品应用范围。     

大塑性变形制备纳米结构金属

细化晶粒是改善材料性能的有效手段，传统的压力加工技术(如轧制、挤压、拉拔和锻造等)可以细化晶粒(微米量级)。纳米结构金属由于具有很小的晶粒尺寸(20-500nm)和独特的缺陷结构，从而表现出优异的物理—力学性能。大塑性变形(SPD)具有将铸态粗晶金属的晶粒细化到纳米量级的巨大潜力，近年来已引起人们的极大关注。介绍了4种大塑性变形制备纳米结构金属的方法、原理、变形特点及应用，分析了纳米结构金属的强度和超塑性变形特征，以及当前研究中存在的主要问题，并对大塑性变形技术的应用前景进行了展望。     

茂金属催化剂气相法聚乙烯中试研究

我国自行开发的茂金属催化剂在气相法聚乙烯中试装置上进行了运行试验和性能试验。考察了茂金属催化剂ＡＰＥ－１的运行稳定性和适应性以及聚合反应条件与催化剂活性、产品熔融流动性能和产品密度的关联性。经过测定，试验所得产品的相对分子质量分布特性与国外同类产品相近。     

橡塑共混热塑性弹性体的形态结构与性能

综述了影响共混热塑性弹性体的形态结构与性能的主要因素。     

低合金高强度钢的微观组织和疲劳裂纹扩展行为

用透射电镜观察了３０ＣｒＭｎＳｉＮｉ２Ａ钢等温的微观组织，疲劳裂纹扩展行为、裂纹尖端塑性区和位错结构，结果表明，等温状态组织由马氏体和贝氏体组成。在一个奥氏体晶粒内一般存在四个板条领域、裂纹尖端的塑性区内存在主位错带，疲劳断裂的基本组织单元为板条晶或板条束。裂纹遇到板条束界时方向发生较大偏斜。     

Liquid viscosities and densities of HFC-134a+glycol mixtures

Liquid viscosity and density of six binary mixtures of HFC-134a with glycols [ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol (400), and polypropylene glycol (2000)] have been measured in the temperature range from 273 to 333 K. The viscosity was measured by a rolling-ball viscometer calibrated with standard liquids of viscosities and densities (JS5, JS10, JS20, and JS50). The density was measured with a glass pycnometer. The uncertainties of the measurements were estimated to be less than 3.4 % for viscosity and 0.04 % for density, respectively. An equation is given to represent the obtained viscosity values as a function of weight fraction and temperature.     

高发泡聚乙烯阻燃初探

根据聚合物燃烧现象和一般阻燃机理寻求研究高发泡聚乙烯的阻燃方法和阻燃剂。研究结果表明:只有对添加型阻燃剂三元并用,方能不降低高发泡聚乙烯的物性,制得较为理想的高发泡聚乙烯自熄型制品。