Chemical Research in Chinese Universities

Table of Content

24 December 1991, Volume 7 Issue 4

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Articles

Determination of Impurity Silicon in Anticancer Drug (Ge-132) by Electrothermally Atomised Atomic Absorption Spectrometry with Optical Temperature Control Accessory

Xie Shujuan, Wang Daning, Zou Mingqiang, Cui Xiaoyuan, Ren Yulin, Zheng Yansheng

1991, 7(4): 205-211.

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The present paper describes the ashing and atomization processes in silicon analysis by electrothermally atomised atomic absorption spectrometry(EAAAS) with an uncoat-ed graphite tube, a pyrolytically coated graphite tube and a tungsten-coated graphitetube. The sensitivity and linear range of three graphite tubes were compared. By using optical temperature control accessory, the signals are enhanced by a factor of 2 and the germanium interferences in the determination of silicon are eliminated. The effects of time constant and carrier gas flow-rate on the determination of silicon were also tested. The sample can be directly analyzed in its aqueous solution without any pretreatment. The measurements of samples containing 0. 2 μg/mL and 0. 4 μg/mL silicon were run ten times and the variation coefficient is 4. 9% and 2.6%, respectively. The recovery tests for carboxyethyl germanium sesquioxide(Ge-132) synthesized and imported were performed, and the recoveries are 97. 0% and 110%, respectively.

Studies on Fragrance Raw Materials of α-Terpineol Analogues

Tang Shixiong, Liu Hong, Wang Changfeng, Cao Yurong, Liao Xiangmin, Wang Xiaolan

1991, 7(4): 212-220.

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Thirty four α-substituted or α, α-disubstituted-(1-methylcyclohexen-4-yl)methanols and α-substituted or α,α-disubstituted-(4-methylcyclohexyl) methanols weresynthesized. Thirty two of them are new compounds. ¹H NMR and IR spectra of allthe compounds were determined, MS spectra of some of them were obtained as well.The characteristic odors were evaluated.

ESR Projection Profile Imaging

Shen Erzhong, Zheng Yingguang

1991, 7(4): 221-226.

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In the present paper we report an ESR imaging algorithm and program based on the projection profile technique, by which the stereograrns and their cross-sectional contour maps of sample spin density can be plotted. As an example, we give some figures in order to demonstrate the applicability and reliability of the program.

Studies on the Electronic Structures of the C₆₀, C₆₀H₆₀ and C₆₀F₆₀

Wang Zhizhong, Shen Erzhong, Wang Liqun

1991, 7(4): 227-230.

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The present paper represents the electronic structures of the cluster C₆₀ and its derivatives C₆₀H₆₀ and C₆₀F₆₀ with FOOT-type of structure. On the basis of the total energies and molecular orbital energies from CNDO/2 calculations the clusters' stabilities, electronic configurations and charge distributions are discussed. The calculation results and discussion are very beneficial to understanding physical and chemical properties of the cluster C₆₀ and its derivatives.

Effects of Various Dopants on Solitons in Polyacetylene

Wang Rongshun, Huang Zhonghao, Meng Lingpeng

1991, 7(4): 231-235.

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The effects of various dopants on solitons in polyacetylene were studied by using CNDO/2 level semiempirical quantum chemical method. The width of solitons is reduced when dopant is present, and the charge density wave(CDW) is further gathered on the carbon atom in soliton center. The effects of p-type of dopants are greater than those of n-type of ones. The charge transfer in doped polyacetylene can be achieved by the propagation of CDW along the chain. The conductivity of doped polyacetylene is proportional to the quantity of charge transfer between dopant and polyacetylene chain.

Non-Isothermal Crystallization Kinetics of PET Under Solid State Poly condensation

Zhou Weihua, Li Liqing, Tang Xinyi

1991, 7(4): 236-242.

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An equation of non-isothermal crystallization kinetics was derived according to a new model and the crystallizations of both the PET samples under solid state polycon-densation and the pre-orientation yarn of high speeding spinning PET were studied with this equation. The results show that there is a good linear relationship between In {-In[1-X(T)]} and lnΦ. The index m in the equation approximately equals to 3 for PET chips and 1. 3 for pre-orientated yarn. At the same temperature, Q(T) decreases with the increase of PET M. W. and the kinetics parameters obtained by Jeziorny' s method indicate that G also decreases with the increase of PET M. W.. Q(T) and Gc show the same varying tendency in the non-isothermal crystallization process.

A Study on Microwave Induced Plasma Ionization Detector for Gas Chromatograph

Yu Aimin, Xu Wenguo, Wang Fendi, Wang Xu, Liu Yun, Jin Qinhan

1991, 7(4): 243-244.

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An Innovative Method for the Determination of Sulfur-containing Compounds by Vapor Molecular Absorption Spectrometry

Duan Yixiang, Zhang Hanqi, Liu Xinwei, Wang Lishuang, Jin Qinhan

1991, 7(4): 245-246.

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