一种新的判断高分子相容性的粘度判据

依据最近提出的高分子稀溶液粘度的浓度 依赖性的团簇理论 ,对高分子‘理想混合物’的定义进行了更新的理论分析 .在此基础上提出了一个新的判定高分子相容性的粘度判据 .从现有的大量实验数据看 ,该判据是和事实相符合的     

The Surface Imprinted Polystyrene Beads Prepared via Emulsion Templates

In this paper, the surface imprinted cross-linked polystyrene beads were prepared via suspension polymerization with styrene (St), divinylbezene (DVB), polyvinyl alcohol (PVA1788),the mixture of Span 85 and xylene or the mixture of Span 85 and paraffin as monomer,cross-linking agent, dispersion stabilizer and templates, respectively. The results indicate that there are dense cavities on the surface of beads, and the diameter and density of cavity are related with the composition and amount of emulsion template. The forming mechanism of cavity from thermodynamics and dynamics was proposed.     

硝酸活化高灵敏度离子选择性电极法测定氟

先在0．5 mol·L-1硝酸介质中活化氟离子选择性电极,再在含硝酸的总离子强度调节混合液(TISAM)中测定氟,线性范围为1×10-7～1×10-2mol·L-1,检出限为1．9μg·L-1。该方法应用于绿茶饮料、水、牛奶中痕量氟的测定,结果的RSD小于4．8％,回收率在96．1％至100．2％之间,对氟离子选择性电极在硝酸介质中的活化机理作了阐述。     

In vitro TRANSFORMATION OF RAT ESOPHAGEAL EPITHELIAL CELLS BY FUSARIN C

Fusarin C (FC) is a mutagenic and carcinogenic mycotoxin which was isolated from Fu-sarium moniliforme culture extracts. The Fusarium moniliforme is one of most prevalent fungi found on corn in Linxian, a high risk area for esophageal cancer. This paper reports, for the first time, the malignant transformation of rat esophageal epithelial cells induced by FC. The transformed cells showed several characteristics of transformation. Colonies were formed after seeding these transformed cells either into selective medium free of epidermal growth factor (EGF) and serum, or on semi-solid agar; there was an increase in chromosome number; the expression of c-myc and v-erb-B oncogenes was enhanced in the cells; and squamous cell carcinomas arose after inoculating the cells into nude mice. The results demonstrated transforming effect of FC on rat esophageal epithelial cells, and indicate that the abnormal expression of some oncogenes could serve as a hew property of transformed cells.     

一种新型可溶性高聚物负载手性配体的合成及其催化烯烃的不对称双羟化反应研究

在碱性条件下, 聚乙二醇单甲醚(HO\|OPEG\|OMe)与1,4-二氟蒽醌进行亲核单取代反应生成中间体F\|AQN-OPEG-OMe, 产率88%. F-AQN-OPEG-OMe与奎宁锂进行亲核取代反应, 以95.6%的产率得到新型手性配体QN\|AQN\|OPEG-Me. QN-QN\|OPEG-Me与OsO4原位配位生成的均相催化剂在4种烯烃的不对称双羟化反应中表现出较高的对映选择性(92%~99%e.e.)和化学产率(80%~94%). 催化活性和立体选择性与Sharpless手性配体(DHQ)2AQN相当. 反应结束后, 配体可用乙醚沉淀回收, 循环使用5次, 催化剂的催化活性和立体选择性无明显改变, 配体的回收率均在95%~97%之间.     

水合醋酸铈直接热分解制备超细氧化铈及其抛光性能

Ultra fine ceria was prepared by calcining hydrate cerium acetate. The effects of pyrolysis temperature on the particle size, morphology, specific surface area and loose packing density of ceria were investigated, and the removal rate of optical glasses polishing by ceria was determined. The results show that with the increase of pyrolysis temperature, the loose deposit density and crystallinity increases and the specific surface area decreases, however, the particle size decreases firstly and then increases, the minimum medium particle size D₅₀ is 0.47 μm at pyrolysis temperature of 1 000 ℃. The SEM images of ceria prepared by the decomposition at 800 ℃ or at 1 100 ℃ show porous powders or quasi-sphere small particles with loosely agglomeration, respectively. It was found that the removal rate varied with pyrolysis temperature in preparation of ceria and the property of glass polished. The removal rate for three kinds of glasses was in the order of ZF7> F1> K9, and the maximum value appeared at around 1 000 ℃ for ZF7 and F1, and at around 1 100 ℃ for K9.     

Ni2（OEt）2／SiO2催化二氧化碳与丙烯直接合成甲基丙烯酸的研究

 采用表面改性法制备了负载型Ni2（OEt）2／SiO2双核金属乙氧基配合物催化剂，利用示差量热、红外光谱和微反技术对催化剂的表面结构、热稳定性、化学吸附性质和催化活性进行了研究．结果表明，负载型双核金属乙氧基配合物Ni2（OEt）2／SiO2中的Ni2＋与载体SiO2表面的O2－以双齿配位形式键合；二氧化碳在催化剂表面存在桥式吸附态和碳酸单乙酯基物种两种吸附态，丙烯则只有一种分子吸附态；在适宜的反应条件下，二氧化碳和丙烯在Ni2（OEt）2／SiO2催化剂上的反应产物主要是甲基丙烯酸．根据实验结果，提出了二氧化碳和丙烯在Ni2（OEt）2／SiO2催化剂表面的反应机理，反应物分子共吸附于催化剂表面同一活性单元上，羧酸根和丙烯解离吸附态的形成是反应顺利进行的关键步骤．     

Fe(0)催化三氯乙酸烯丙酯的环化反应研究

通过对Fe(O)催化烯烃自由基环化反应的研究，发现以Fe(O)为催化剂催化三氯 乙酸烯丙酯分子内自由基环化反应可以高化学选择性得到五元环内酯产物，反应中 不需加入配体。和大多数自由基反应一样，反应温度与催化剂用量对该反应的转化 率和产率有着很大的影响。     

燃烧法测定镀铬液中硫酸

镀铬液中的硫酸含量对镀铬液的影响很大，而一般测定的方法是硫酸钡沉淀法。该方法较为繁琐冗长，费时费力。本法依据钢铁燃烧法测定碳、硫的原理，用管式炉测定镀铬液中硫酸，方法快速准确。     

尺寸排除色谱扩展因子的保留体积依赖性

尺寸排除色谱扩展函数的方差即尺寸排除色谱柱中单分散高分子峰的扩展因子,以窄分布聚苯乙烯标样用分子量分离和扩展效应同时标准的方法作了测量。简单的理论分析导出了一个方程以表示扩展因子的保留体积依赖性,其中包括四个具有明确物理意义并可实验测量的参数。该方程与实验数据符合得相当好,并解释了扩展因子极值出现的条件。