苯烃化和四聚丙烯共用一套装置的设计与使用

介绍兰州炼油化工总厂苯烃化和四聚丙烯工艺交替使用同一套装置的设计。由于两种工艺所用催化剂相同，反应机理和原料类同，所以可共用原料系统、反应系统和一些设施，节省用地４５２４ｍ２。依靠技术进步，节能降耗，每年获经济效益６６０万元     

烯烃均相茂金属催化技术的工艺条件

烯烃均相茂金属催化技术的工艺条件潘智达孙俊全杨士林（浙江大学高分子科学与工程系，杭州３１００２７）ＰａｎＺｈｉｄａ，ＳｕｎＪｕｎｑｕａｎａｎｄＹａｎｇＳｈｉｌｉｎ（ＤｅｐａｒｔｍｅｎｔｏｆＰｏｌｙｍｅｒＳｃｉｅｎｃｅａｎｄＥｎｇｉｎｅｅｒｉｎｇ，Ｚｈ...     

An eight‐node hybrid‐stress solid‐shell element for geometric non‐linear analysis of elastic shells

This paper presents eight‐node solid‐shell elements for geometric non‐linear analysis of elastic shells. To subdue shear, trapezoidal and thickness locking, the assumed natural strain method and an ad hoc modified generalized laminate stiffness matrix are employed. A selectively reduced integrated element is formulated with its membrane and bending shear strain components taken to be constant and equal to the ones evaluated at the element centroid. With the generalized stresses arising from the modified generalized laminate stiffness matrix assumed to be independent from the ones obtained from the displacement, an extended Hellinger–Reissner functional can be derived. By choosing the assumed generalized stresses similar to the assumed stresses of a previous solid element, a hybrid‐stress solid‐shell element is formulated. Commonly employed geometric non‐linear homogeneous and laminated shell problems are attempted and our results are close to those of other state‐of‐the‐art elements. Moreover, the hybrid‐stress element converges more readily than the selectively reduced integrated element in all benchmark problems. Copyright © 2002 John Wiley & Sons, Ltd.     

苯并口恶嗪-环氧化合物-胺类催化剂体系开环聚合反应的研究

采用TLC，GPC，1H－NMR及IR等分析方法，对苯并恶嗪－环氧化合物－胺类催化剂体系的聚合反应进行了研究，表征了产物结构，并探讨了聚合反应机理，结果表明，苯并恶唪－环氧化合物体系在胺类催化剂如苄胺，咪唑的作用下，能发生开环聚合反应，生成低分子量的聚合物。     

纳米聚N-异丙基丙烯酰胺微凝胶的光引发聚合

选择具有温敏性的高分子单体N－异丙基丙烯酰胺（N－isopropylacrylamide，NIPAM）为主单体，N，N′－亚甲基双丙烯酰胺（methylenebisacrylamide，MBA）为交联剂，运用光引发无皂乳液聚合的方法合成出粒径小于100nm的高分子微凝胶，并研究了在改变体系组成和条件时微凝胶粒径的变化。结果显示，在乳化剂临界胶束浓度以下，随着乳化剂浓度的提高，微凝胶粒子的粒径不断关小且趋向稳定；相比于热引发，产生的微凝胶具有较高的单分散性而且粒径较小。     

给定拓扑结构的网络的可靠性设计

本文首先讨论了网络链路堵概率的加权平均值，提出了网络分配的一般准则，并在考虑了网络链路生存链路概率的因素后，提出了更一般的网络链路堵塞概率的加权平均值，以此为基础，分别讨论了网络在给定点的费用条件下，使得网络可靠性最大的网络设计问题，以及在给定网络可靠性指标的前提下，使得网络费用最小的网络设计问题。     

高温润滑涂层设计的系统考虑

航天、航空、核能等尖端技术迫切要求使用耐高温润滑涂层，以保护金属构件的表面，增加发动机、推进器的工作效率和输出功率，８０年代国际摩擦学界根据工业和国防的需要将高温润滑涂层和耐磨材料定为摩擦学学科发展的重要研究方向之一。本文对高温润滑涂层设计中遇到的典型环境、涉及到的关键问题、未来发展的途径等问题作了阐述。     

分子振动态及其跃迁的激光相干控制

讨论了激光合成相干叠加态的原理及其性质 ,针对 XY2 型分子 ,证明了合成局域模振动的可行性 ,然后给出相干叠加态的跃迁几率特征 ,发现它仍表现出相干的特性 ,对之进行分析研究表明 ,分子的振动态具有可控性 ,态跃迁几率具有可控性。     

Probing the early stages of polymerization of ethylene on a model chromium/silica catalyst by Fourier transform infrared spectroscopy

The nature of the interaction of monomer, and the early stages of growth of oligomers of ethylene on a rather more uniform surface of Cr/SiO₂ catalyst than hitherto studied has been investigated by differenceFTIR spectroscopy using C₂D₄ and C₂H₄ as reactants both with and without subsequent treatment of the catalyst with CO andTHF. The active catalyst was prepared by reaction of vapour phase CrO₂Cl₂ with the vicinal hydroxyls of the silica surface. Three distinct kinds of methylene groups were detected. Arguments are given for assigning the peaks at 2935 and 2860 cm^–1 to CH₂ groups directly bound to the active site and those at 2920 and 2850 to CH₂s in the growing chain well removed from the Cr. The peaks at 2160 and 2165 cm^–1 are attributed to CD₂ groups hydrogen bonded to surface hydroxyls.     

Effects of a Nd—Fe—B magnetic filler on the crystallization of poly(phenylene sulfide)

The crystallization of poly(phenylene sulfide) (PPS) in a polymer–magnetic Nd—Fe—B powder suspension was studied. Isothermal crystallization behavior was analyzed by way of differential scanning calorimetry, and the kinetics were described via the Avrami equation. The Avrami parameters and the crystallization times were strongly affected by both the particle size and the presence of a coupling agent coated on the filler particles. The small Nd—Fe—B particles exhibited long induction and half‐times, whereas the large particles tended to have short crystallization times. Particles ranging from 38 to 150 μ appeared to have similar crystallization times and to have no significant change in the value of Avrami index with melt crystallization temperature. As a result of these analyses, the dynamic mechanical properties were determined to correlate the fundamental polymer crystallization characteristics and the physical properties of the PPS binder. The enhancement of the wetting of the filler to the binder was promoted through the coupling agent, as confirmed by dynamic mechanical testing performed on the samples. The storage modulus typically decreased because of the presence of the uncoated small particles. Conversely, the loss modulus was enhanced because of the presence of the coated small particles in the PPS binder. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1091–1102, 2002