Dependence of the kinetics of the anionic polymerization of methyl methacrylate on the concentration in active centers

Studies on the anionic polymerization of methyl methacrylate in tetrahydrofuran and in the presence of sparteine have revealed a beneficial effect due to this additive, resulting in a decrease in the extent of termination. Better control of the definition of the polymers formed can thus be achieved in the presence of this additive. On the other hand, macromolecular engineering requires a range of active species concentrations lower than 10^?3 mol L^?1 and particularly the synthesis of polymers of high molar masses. For a better understanding of the mechanism of chain growth under such concentration conditions, the kinetics of polymerization have been investigated with a technique based on adiabatic calorimetry. Sparteine has been found to lack sufficient cation‐binding power to prevent the propagating enolate ion pairs from aggregating. The rate constant of propagation of nonaggregated species has been estimated, as well as the aggregation constant of equilibrium. For very low initiator concentrations, termination reactions have been shown to profoundly alter the control of the polymerization and to prevent a quantitative monomer conversion. Theoretical maximal conversions have been calculated from kinetic data and compare well with the experimental values. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 4964–4975, 2004     

Preparation and characterization of finely dispersed drugs. 5. Ethyl 3,5-di(acetylamino)-2,4,6-triiodobenzoate

Controlled precipitation of the diagnostic imaging agent ethyl 3,5-di(acetylamino)-2,4,6-triiodobenzoate has been used to produce fine particles of various sizes, morphologies, and degrees of crystallinity, which depended on experimental conditions. In addition, two distinct polymorphic forms of the drug have been fully characterized by single crystal X-ray diffraction studies, and evidence for a third polymorph was also observed. Some of the so prepared dry particles were coated with a thin layer of silica.     

Studies on calcium‐containing poly(urethane ether)s

The calcium salt of mono(hydroxyethoxyethyl)phthalate [Ca(HEEP)₂] was synthesized by the reaction of diethylene glycol, phthalic anhydride, and calcium acetate. Calcium‐containing poly(urethane ether)s (PUEs) were synthesized by the reaction of hexamethylene diisocyanate (HMDI) or tolylene 2,4‐diisocyanate (TDI) with a mixture of Ca(HEEP)₂ and poly(ethylene glycol) (PEG₃₀₀ or PEG₄₀₀) with di‐n‐butyltin dilaurate as a catalyst. A series of calcium‐containing PUEs of different compositions were synthesized with Ca(HEEP)₂/PEG₃₀₀ (or PEG₄₀₀)/diisocyanate (HMDI or TDI) molar ratios of 2:2:4, 3:1:4, and 1:3:4 so that the coating properties of the PUEs could be studied. Blank PUEs without calcium‐containing ionic diols were also prepared by the reaction of PEG₃₀₀ or PEG₄₀₀ with HMDI or TDI. The PUEs were well characterized by Fourier transform infrared, ¹H and ¹³C NMR, solid‐state cross‐polarity/magic‐angle‐spinning ¹³C NMR, viscosity, solubility, and X‐ray diffraction studies. The thermal properties of the polymers were also studied with thermogravimetric analysis and differential scanning calorimetry. The PUEs were applied as top coats on acrylic‐coated leather, and their physicomechanical properties were also studied. The coating properties of PUEs, such as the tensile strength, elongation at break, tear strength, water vapor permeability, flexing endurance, cold crack resistance, abrasion resistance, color fastness, and adhesive strength, were better than the standard values. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2865–2878, 2003     

也论中西精神--与张秀成先生商榷

本文认为，中学和西学各有优劣，应互相吸取，但在总体上是西学优于中学。首先，在思维方式上，西学的分析思维，使西方社会分工较细，促进了社会化大生产的产生；也使西学学科门类众多；西学在方法上崇尚专精深，对任何问题都穷追不舍，非要证明或证伪，促进了科学的进步。中学的综合思维则使中国社会分工不细，学科门类不多，在研究方法上则不究细节。其次在义利关系上，西方私有神圣，最后却私也有了公也有了；中国公有神圣，改革开放前却公也没有私也没有。再次，在男女关系上，西学以个体为本，正是为了自身的尊严不受侵犯，才不得侵犯他人的尊严，这就有了平等精神。相反，古代中国的根本大法是三纲五常，夫为妻纲、男尊女卑，被论述为符合阳主阴辅的天道法则，追求男女平等，就是违反天道，就会被天诛地灭，中国没有男女平等。     

可编程控制器调速器

本文以联合研制成功的水电站可编程控制调速器为对象，详细介绍其硬件与软件构成及工作原理。同时，对多种调节模式等方面也进行了一些探索。     

Does an all-sulphur analogue of heptamolybdate exist?

The complexes [MoX₄]²⁻ (M = Mo; X = O or S) exist as the monomeric tetrahedral species in aqueous alkaline solutions. Acidification of tetraoxomolybdate results in the condensation of the tetrahedral units via a series of polyoxomolybdates leading to the ultimate formation of the trioxide MoO₃. Heptamolybdate [Mo₇O₂₄]⁶⁻ is the first major polyanion of the acidification reaction. In contrast, acidification of tetrathiomolybdates leads to the formation of amorphous molybdenum trisulphide via a dinuclear Mo(V) complex. The formation of the dinuclear Mo(V) complex precludes the formation of any higher nuclearity Mo(VI)-S complexes in aqueous solution. Thus it is shown that the all-sulphur analogue of heptamolybdate [M0₇S₂₄]⁶⁻ does not exist in alkaline medium and also cannot be isolated from aqueous acidic medium     

永不消失的白螺号——访藏学大师东噶·洛桑赤列先生

东噶·洛桑赤列教授是享誉国际国内的藏学家，国家级专家，曾担任中国藏学研究中心副总干事和西藏社会科学院名誉院长等行政职务，先后任中央民族大学藏学院、西藏大学文学院教授。在他长期的坎坷人生经历中，由一名农奴成为著名的藏传佛教活佛，由一名俄让巴密宗师转变为接受马克思主义的教授，成为著述等身的大师级学者。先后经历过新旧社会的变革，新旧文化的熏陶，他的学术思想在无数磨砺中闪闪发光，他的天资在特殊的文化环境中释放出无穷的能量，他的人品、治学精神，在学术领域永无止境的追求探索的精神和他留下的20多部学术著作，已经成为中华民族一笔宝贵的文化遗产。文章根据1984年冬至1997年2月之阍陆续采访的记录（手稿），主要对东噶·洛桑赤列先生的人生历程、研究成果、学术观点、治学精神等方面的内容进行了摘编。     

群速度和相速度的微机模拟

本文介绍了作者开发的群速度和相速度微机模拟软件的程序设计和实现．该软件做为演示实验已经取得了良好的效果．     

钟敬文与杭州中国民俗学会的活动及历史地位

杭州中国民俗学会是中国民俗学发展史中具有特殊意义的一个阶段，这一阶段的特殊性就在于它不仅建立起一个松散的同仁性组织，还在于通过民俗学者，尤其是钟敬文先生的努力，使中国民俗学开始变得成熟和具有现代性，对后来的民俗学研究产生了巨大的影响。     

Antimicorbial effects of newly synthesized organotin(IV) and organolead(IV) derivatives

Triorganotin(IV) and triorganolead(IV) derivatives of the types Me₃Sn(SCZ) and Ph₃Pb(SCZ) (where SCZ^? is the anion of a semicarbanzone ligand) have been synthesized by substitution reactions of trimethyltin chloride and triphenyl-lead chloride with semicarbazones derived from heterocyclic ketones. The resulting complexes have been characterized by elemental analyses, molecualr weight determinations and conductivity measurements. The mode of bonding has been established on the basis of infrared and ¹H, ¹³C and ¹¹⁹Sn NMR spectroscopic studies. Some respresentative complexes have also been evaluated for their antimicrobial effects on different species of pathogenic fungi and bacteria; the results of these investigations have been reported in the present paper.