THE CHEMICAL COMPOSITIONS OF MINERALS IN QINGZHEN METEORITE AND ITS GEOCHEMISTRY SIGNIFICANCE

The chemical compositions of silicate minerals, sulphide minerals and metal Fe-Ni in theQingzhen meteorite were measured by the microprobe analyses. Based upon these chemicalcompositions, the cosmochemical behaviour and characteristics of the existing forms of themajor elements in the Qinzhen meteorite have been discussed. These characteristics show thatunder the S-rich, O-poor, and strongly reducing conditions, the light metal elements, such asCa, Mg, K, Na may form sulphide, and metal Fe-Ni may contain Si and P. However, we con-sider that the light metal-sulphide can be stable in the lower mantle and there are some Siand P in the Fe-Ni core. Finally, an earth core-mantle model is established, where the Fe-Ni core contains some Si and P; the lower mantle is composed of Mg-rich silicate, SiO_2 andsulphide; the upper mantle, of silicate and oxide.     

THE STUDY OF 2-CHLORO-5,5-DIMETHYL-2-OXO-1,3,2-DIOXAPHOSPHORINANE IN SOLUTIONS BY MOLECULAR DYNAMICS METHODS USING IR AND RAMAN SPECTROSCOPY

Abstract

2-Chloro-5,5-dimethyl-2-oxo-1,3,2-dioxaphosphorinane has been studied in CCl₄, CHCl₃ and CD₃CN solutions by IR and Raman line shape analysis. Equilibrium process of dimerization and ring conversion in CCl₄ solutions have been considered. On the contrary to the commonly expected dominance of the conformer with the equatorial oriented P[dbnd]O bond for 2-halo-2-oxo-1,3,2-dioxaphosphorinanes, it was found that for the 2-chloro derivative both conformers are nearly equally distributed. It has been shown that the interactions induced absorption is an important mechanism of relaxation in the studied compound and this mechanism gives significant contribution to the total IR band broadening, while the interaction induced light scattering is negligible. The obtained results show that the molecular dynamics method can be useful in studying cyclic compounds in solutions.     

高频红外吸收法测定钽粉、铌粉和碳化钽中的碳

用HCS-140型高频红外碳硫分析仪测定钽粉、铌粉、碳化钽中的碳,进行了助熔剂、称样量、氧气流量试验,在不需测硫的情况下,采用铜和钨作助熔剂、称样量为0．5g、氧气流量为2L／min时,测定结果满足分析要求。     

两亲两嵌段共聚物PS-b-PAA合成及其在溶液中的形态和纳米聚集结构形成

采用了ATRP方法合成了由苯乙烯及丙烯酸组成的两亲两嵌段共聚物PS b PAA ,对它们的结构组成进行了详细表征 .用荧光探针方法以二甲基氨基黄酮类化合物为探针测定了这类两亲高分子化合物的类胶束形成时的临界浓度 .并对它们所形成的特殊胶束形态通过电镜观察 ,清楚的看到在纳米线条形成过程中由纳米小球向纳米线的转变