Solubility of Propane in Sulpholane at Elevated Pressures

The solubility of propane in sulpholane has been determined at temperatures in the range 298‐403 K at pressures up to 17.6 MPa. The experimental results were correlated by the Peng‐Robinson equation of state, and binary interaction parameters have been obtained for this system. The parameters in the Krichevsky‐Ilinskaya equation were calculated from these interaction parameters.     

Synthesis and characterization of side‐chain cholesteric liquid‐crystalline polymers derived from steroid substituents

A series of new cholesteric liquid‐crystalline polysiloxanes derived from steroid substituents were synthesized. The chemical structures of the monomers or polymers obtained were characterized by FTIR, element analyses, ¹H NMR, and ¹³C NMR. Their mesogenic properties and thermal stability were investigated by differential scanning calorimetry, thermogravimetric analysis, polarizing optical microscopy, and X‐ray diffraction measurements. Monomers exhibited typical cholesteric focal‐conic or spiral texture. The polymers P ₁? P ₆ showed cholesteric phase and P ₇ displayed smectic phase. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006     

Effects of heat treatment on tensile properties of diacetate fibers

Diacetate filaments were heat‐treated (without tension or with tension) under dry‐heat or wet‐heat environment, respectively. The effects of temperature, time, and tension on tensile properties of diacetate fibers after heat treatments were discussed. The results show that diacetate fibers present no obvious improvement on its tensile properties after dry‐heat treatments without tension. It was also found that during dry heat treatments with tension, the increase in tensile properties of fibers mainly depends on temperature and tension. Moreover, being dry‐heat treated with tension instant after wet‐heat treatment without tension, diacetate fibers exhibit a higher improvement on its tensile properties comparing with dry heat method with tension. The shrinking measurement for the fibers indicates different supermolecular structures were developed in the fiber before treatment and after treatment, which leads to the different extent in the improvement of tensile properties for the fibers. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101:787–791, 2006     

Nonisothermal crystallization behavior of glass‐bead‐filled polypropylene

The effects of the glass‐bead content and size on the nonisothermal crystallization behavior of polypropylene (PP)/glass‐bead blends were studied with differential scanning calorimetry. The degree of crystallinity decreased with the addition of glass bead, and the crystallization temperature of the blends was marginally higher than that of pure PP at various cooling rates. Furthermore, the half‐time for crystallization decreased with an increase in the glass‐bead content or particle size, implying the nucleating role of the glass beads. The nonisothermal crystallization data were analyzed with the methods of Avrami, Ozawa, and Mo. The validity of various kinetic models for the nonisothermal crystallization process of PP/glass‐bead blends was examined. The approach developed by Mo successfully described the nonisothermal crystallization behavior of PP and PP/glass‐bead blends. Finally, the activation energy for the nonisothermal crystallization of pure PP and PP/glass‐bead blends based on the Kissinger method was evaluated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2026–2033, 2006     

Organocatalytic and Stereoselective [3 + 2] Cycloadditions of Azomethine Imines with α,β‐Unsaturated Aldehydes

Bipyrazolidin‐3‐one derivatives are biologically significant compounds and their importance has increased in the past decades. In this paper, the first stereoselective [3 + 2] dipolar cycloadditions of azomethine imines with α,β‐unsaturated aldehydes catalyzed by readily available α,α‐diarylprolinol salts are reported, providing a facile route to the synthesis of various chiral bipyrazolidin‐3‐one derivatives under mild conditions. The organocatalyst 1 g with strongly electron‐withdrawing groups exhibited the best stereoselectivity (exo:endo up to 98:2, for exo product up to 97 % ee), in the combination with trifluoroacetic acid.     

对苯二甲酸（PTA）间歇酯化反应计算机模拟

为了研究不同的工艺操作参数对ＰＴＡ转化率和副产物形成的影响，针对ＰＴＡ间歇酯化建立了一较完善的反应模型．模拟过程中考虑了重要工艺参数如乙二醇（ＥＧ）与ＰＴＡ配比、温度等的影响，对既能达到最高生产效率又能最小限度减少副产物的工艺参数范围提出了建议．     

橡胶注射充模过程的数值分析

借鉴塑料熔融注射技术，研究了胶料粘弹性引起的入口附加压力降和固体壁面滑移速度对充模过程的影响，从而建立了橡胶在薄矩形模腔内充模流动的数学模型。采用有限单元和有限差分混合方法求数值解。通过计算程序预测了充模过程中前锋线的移动及流动场，并根据模拟计算结果，分析讨论了各因素对充模压力的影响。     

离心式压缩机转子弯曲振动特性及安全性分析

提供了一种改进的计算转子特征值和特征向量的方法，由系统的传递矩阵推得刚度、阻尼和质量矩阵，然后用传递矩阵法分析了转子的不平衡响应。最后提供了用以上方法分析的一个压缩机转子弯曲振动的例子，并着重用ＡＰＩ６１７标准对其进行了校核     

我国生物工程发展的现状与展望

我国在８０年代初即将生物工程确定为科技和产业发展的重要领域，制订了发展的战略目标和具体规划，组织了攻关队伍，采取各种措施，使我国生物工程的发展走上了有计划的迅速发展道路，取得了许多重大的突破性进展，为在本世纪末形成一定规模的生物工程新产业，跻身世界生物工程先进行列，打下了坚实基础。