复合材料RTM模具的制备

根据树脂传递模塑(RTM)模具对基体树脂的基本要求,选用双酚A环氧乙烯基酯树脂为基体,聚乙酸乙烯酯为低收缩添加剂,玻璃纤维经编织物为增强材料,并加入相应的助剂,制备了复合材料RTM模具。该模具具有成本较低、开发周期短、精度较高等优点,但表面强度和热效率较低。     

活性端基聚氨酯橡胶改性不饱和聚酯树脂的研究(Ⅱ)

通过在不饱和聚酯树脂中加入活性端基聚氨酯橡胶来降低树脂的体积收缩.树脂固化前,橡胶与不饱和聚酯树脂相溶性好;树脂固化时橡胶中的不饱和双键反应可参与反应,并呈一定粒径的胶粒析出.本文研究了几种活性端基聚氨酯橡胶对不饱和聚酯树脂收缩控制的影响.     

定容条件下火药实际燃烧规律的数值模拟

为研究火药的实际燃烧规律,建立了定容条件下火药燃烧的修正数学模型,分析了火药实际弧厚的分布及变化、点火不同步和燃速系数变化等因素对火药实际燃烧规律的影响。在此基础上,用考虑综合因素的修正数学模型对定容条件下火药的实际燃烧过程进行了模拟,计算值与实验结果具有较好的一致性,说明修正模型所建立的假设及处理方案是合理的。     

柔软热收缩材料的研制

总结了经共混和辐射交联制备柔软耐老化的热收缩材料的研制过程。测得了不同乙丙橡胶含量和不同辐照剂量下的共混物的力学性能和凝胶含量，确定了共混物辐射交联的合适剂量。此外，还测试了ＥＰＤＭ和ＰＥ共混物经辐照后的耐油性能。在此基础上，制得了手感柔软的热收缩管材。     

考虑土体强度参数深度依赖性的非平稳随机场边坡滑动深度和体积分析

基于随机有限元方法（RFEM）和Monte-Carlo模拟,建立了能够模拟具有深度依赖性的土体强度参数边坡或具有软弱夹层边坡的非平稳随机场模型。通过辐射扫描方法获取最危险滑动面,得到非平稳随机场边坡滑动深度和滑动体积。将该方法与均质边坡和平稳随机场边坡获得的滑动深度和滑动体积进行对比,研究土体强度参数深度依赖性的非平稳随机场边坡的不同坡度和各向异性对滑动深度和滑动体积的影响。结果表明：基于RFEM的非平稳随机场滑动深度和滑动体积结果为地质灾害风险及后果评估提供了一个参考分析的新角度;参数的深度依赖性程度越高(变化率b越大),则边坡平均滑动深度和滑动体积越小;在大坡度滑坡风险后果评估中,可以基于均质边坡分析结果进行初步预估;在非平稳随机场中,随着各向异性的增大,所有坡度边坡的滑动体积变异系数增大;不同坡度下,水平方向的相关程度越大,则土坡内软弱夹层的不确定性越强,滑动体积的变异系数也不断增大。     

Numerical solution of viscous flow past a solid sphere with the control volume formulation

The control volume formulation with the QUICK finite difference scheme is used to solveincompressible liquid flow past a solid sphere in terms of stream function and vorticity.Several tech-nical points are addressed on improving the accuracy and efficiency of numerical simulation of similarproblems of fluid flow.In particular,the importance of suitable specification of the distortion func-tion to enforcing the far field boundarv conditions is emphasized.     

Volume phase transition of polyelectrolyte gels in dimethyl sulfoxide/ tetrahydrofuran mixtures

Copolymer gels were prepared from 2-(acrylamido)-2-methylpropanesulfonic acid (AMPS), N,N-dimethylacrylamide (DMAA, comonomer) and N,N′-methylenebis(acrylamide) (BIS). The mole fraction of AMPS were 0.2674 and 0.4318, respectively, with the same BIS mole fraction of 0.013. These gels with counterions H⁺, Na⁺, and K⁺ were swollen at 25°C in mixtures of dimethyl sulfoxide (DMSO) and tetrahydrofuran (THF). A volume phase transition was observed at the THF volume fraction of about 0.58, indicating that the volume phase transition in a polyelectrolyte gel occurs when the medium polarity decreases sufficiently for ion-pair formation. On changing the counterion, the fraction of DMSO in the solvent mixture which is required to initiate swelling decreases in the order Na⁺, H⁺, and K⁺, the same as for counterion condensation in identical gels.     

纺速对聚酯工业丝干热收缩率的影响

通过对不同纺速的高粘聚酯初生丝的结构的测试,探讨了初生纤维结构随纺速变化的规律,以及初生丝的结构对成品工业丝的干热收缩率的影响。     

Investigation of free volume,interfacial, and toughening behavior for cyanate ester/bentonite nanocomposites by positron annihilation

Effects of filler on microstructure and toughening behavior of cyanate ester (CE)/bentonite (BT) nanocomposites with different content of BT have been studied by positron annihilation lifetime spectroscopy, X‐ray diffraction, transmission electron microscopy, dynamic mechanical analysis, etc. The interesting results found by PALS indicate that the size and concentration of the free volume holes and the apparent free volume fraction increased with increasing the content of BT, which indicates that adding nano‐layers to thermosetting materials can lead to the high crosslinking density structure “looser.” The experimental results reveal that the increases in size of free volume holes and apparent free volume fraction are related to the increasing conversion of cure reaction. On the other hand, the mechanism of toughening (by adding the nano‐clay to the thermosetting material) has been discussed by combining free volume and interfacial property. It is shown that, for the high crosslinking thermosetting material‐based nanocomposites, both the property of free volume and dispersion state of nano‐layers are the two key factors in determining toughening property. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1509–1515, 2006     

新型绝缘树脂及应用

本文介绍了FUCHEM系列无溶剂绝缘树脂的性能及应用，着重探讨了产品的阻燃、低收缩、高耐腐蚀、高耐热等级等特性。