SYNTHESIS AND CHARACTERIZATION OF A SOLUBLE LADDERLIKE POLYSILSESQUIOXANE CONTAINING REACTIVE ESTER GROUPS*

A novel soluble ladderlike polysilsesquioxane containing reactive ester groups (Ester-T) was synthesized for thefirst time by stepwise coupling polymerization including preammonolysis, controlled hydrolysis and polycondensation. Themonomer, 3-trichlorosilylpropoxy 4-acetoxybenzoate (M), was synthesized by hydrosilylation of allyloxy 4-acetoxybenzoatewith trichlorosilane in the presence of dicyclopentadienylplatinum (II) chloride (Cp_2PtCl_2) catalyst. Combination of FTIR,~1H-NMr, ~(13)C-NMR, ~(29)Si-NMR, XRD, DSC, TGA and VPO methods was used to demonstrate that the polymer obtained hasan ordered ladderlike structure. The synthesized Ester-T may have promising applications as a precursor of advanced functional polymers.     

Multipulse feed strategy for glycerol fed-batch fermentation

During glycerol fed-batch fermentation, the process could be divided into multiple equal subintervals, and the feed operation was performed in pulse form at the start of each subinterval. Based on the macrokinetic models, the multipulse feed strategy for both glucose and corn steep slurry was determined by a general nonlinear optimization approach to maximize the final glycerol productivity and still control the residual glucose at a low concentration. The experimental results in a 600-mL Airlift Loop Reactor showed that the tested data with this strategy agreed well with the corresponding model prediction, and that the feed mode with nonlinear optimization could improve the glycerol productivity significantly compared with those determined just by limited experimental optimization in previous studies.     

气固相法合成的Ti-ZSM-5催化剂上苯乙烯氧化反应的宏观动力学

 采用TiCl4气固相同晶取代法制得的Ti－ZSM－5作催化剂,对H2O2氧化苯乙烯反应的宏观动力学进行了研究,考察了催化剂、苯乙烯和H2O2用量及反应温度对苯乙烯氧化反应速率的影响．结果表明,催化剂Ti－ZSM－5和底物苯乙烯对苯乙烯氧化反应速率的贡献均为一级,而H2O2为1／2级;苯乙烯氧化反应的表观活化能Ea＝48．14kJ／mol．当以丙酮为溶剂,在n（PhCH∶CH2）／n（H2O2）＝7．91,催化剂用量为20g／L,反应温度为343K的条件下,反应360min时,苯乙醛选择性和H2O2利用率分别可达91．9％和88．6％．     

大分子单体聚N-乙烯甲酰胺与苯乙烯共聚合成热敏性功能高分子微球

用自由基聚合法合成了大分子单体聚N 乙烯甲酰胺和功能高分子微球 .用GPC、分光光度仪和扫描电子显微镜等对合成的聚合物进行了表征 .研究结果表明 ,大分子单体聚N 乙烯甲酰胺和功能高分子微球具有明显的热敏性特性 ,且合成的功能高分子微球具有单分散性 ,粒径在 1～ 5 μm之间     

利用分子烙印技术分离中草药活性组分

用非共价法,在极性溶剂中,以丙烯酰胺作功能单体,以强极性化合物槲皮素为模板 ,制备了分子烙印聚合物(MIP). 液相色谱实验表明, MIP 对槲皮素具有特异的亲合性.将此 MIP直接分离银杏叶提取物水解液, 得到主要含模板槲皮素及与槲皮素结构相似化合物山奈 酚两种黄酮的组分.研究证实了MIP技术用于直接分离、提取中草药中具有特定药效化合物的 可行性.     

Synthesis and characterization of a novel soluble reactive ladder‐like polysilsesquioxane with side‐chain 2‐(4‐chloromethyl phenyl) ethyl groups

A new kind of soluble structure‐ordered ladder‐like polysilsesquioxane with reactive side‐chain 2‐(4‐chloromethyl phenyl) ethyl groups ( L ) was first synthesized by stepwise coupling polymerization. The monomer, 2‐(4‐chloromethyl phenyl) ethyltrichlorosilane ( M ), was synthesized successfully by hydrosilylation reaction with dicyclopentadienylplatinum(II) chloride (Cp₂PtCl₂) ­catalyst. Monomer and polymer structures were characterized by FT‐IR, ¹H‐NMR, ¹³C‐NMR, ²⁹Si‐NMR, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), vapor pressure osmometry (VPO) and X‐ray diffraction (XRD). This novel reactive ladder‐like polymer has promise potential applications as initiator for atom transfer radical polymerization, and as precursor for a variety of advanced functional polymers. Copyright © 2001 John Wiley & Sons, Ltd.     

Bands of weakly r-Archimedean ordered semigroups

In this paper, some characterizations that an ordered semigroup S is a band of weakly r-archimedean ordered subsemigroups of S are given by some relations on S . We prove that an ordered semigroup S is a band of weakly r -archimedean ordered subsemigroups if and only if S is regular band of weakly r -archimedean ordered subsemigroups. Finally, we obtain that a negative ordered semigroup S is a band of weakly r-archimedean ordered subsemigroups of S if and only if S is a band of r-archimedean ordered subsemigroups of S . As an application the corresponding results on semigroups without order can be obtained by moderate modifications. August 27, 1999     

提高图书质量的层次分析

本列举了影响图书质量的诸多因素,构造了图书质量的层次结构图,利用层次分析原理,计算了各因素的相对权重,为提高图书质提供了一个定量模型。     

The Hubble diagram of metal-rich QSOs and deceleration parameter q0

For 163 metal-rich Quasars, the m_v-logZ diagram shows a very close correlation. Using multiple regression analysis for these sources (N = 163), we obtained q₀,= 1.142 and correlation coefficient γ = 0.69. These results suggested that the Universe is closed and all metal-rich quasars are of a single category. On the other hand, the evolution is very small at Z⩽2 for metal-rich quasars.     

三模共振光学参变振荡腔中热效应与热自锁定的实验研究

通过在压电陶瓷上加不同扫描速度的三角波电压,对光学参变振荡腔进行腔长扫描,发现内腔非线性晶体的热效应会严重影响共振峰值功率,从而可能用以建立光学参变振荡腔频率的热自锁定,对热效应进行了细致的实验观察并对实验现象作了合理的分析。