The Crystallization of Poly (3-dodecyltbiophene) in an Oriented Solidification Environment

Poly (3-alkylthiophenes) (P3ATs) have made up of a family of conductive polymerswhich are soluble, fusible and processable, since the introduction of flexible alkyl sidechains"'. It is generally accepted that P3ATs can form similar layered structures. inwhich the thiophene rings possess planarity and the side chains act as spacers'-'. Whenthe number. of 'carbon atoms of alkyl side chains is more than 10, some orderlyarrangements will occur for side chains betWeen the' layers'. It has been w…     

流动注射-电感耦合等离子体发射光谱法测定天然水中的钙和镁

本文采用流动注射－电感耦合等离子体发现光谱联用技术测定了天然水中的钙、镁元素。考察了试液的雾化和曝光时间及载气压力等因素对分析信号的影响。通过与气动连续进样的对比，测出了钙、镁在流动注射进样下的分散系数。本法在测定钙、镁含量高的水性时，不需对试样进行稀释处理。对五个水样中钙、镁的分析结果与EDTA络合滴定法相吻合。     

Symmetrization of matrix technique in a finite element context

A finite element Galerkin-based formulation of the mass conservation and momentum equations can require, if convective type terms are retained in the coefficient matrix, a non-symmetric solver. The resulting increase in core storage for efficient utilization of CPU time can be considerable. The current paper advocates a simple symmetrization of matrix technique, at element level which results in a considerable reduction in core requirement. The increase in CPU time required when solving linear systems of equations is considerable. However, for nonlinear systems the penalty can be negligible.     

The polarography of oximes: I. 9,10-Phenanthraquinone monoxime

Polarography of 9,10-phenanthraquinone monoxime has been carried out in buffers (pH 3.50 to 13.40) of constant ionic strength 0.5 M in 40% alcoholic solutions at 35 ± 0.5 °C. The oxime group underwent diffusion-controlled reduction (4e) over the whole pH range studied. The number of electrons involved in the reduction was found coulometrically as well as by incorporating the value of the diffusion coefficient, obtained by using a McBain-Dawson cell, into the Ilkovic equation. Controlled potential electrolyses and uv spectroscopic methods were used to identify the products. Koutecky's method was used to compute the kinetic parameters (αn_aand ?log k_f,h^o) for the reduction of the oxime group and reduction mechanisms are proposed.     

Pseudohalide derivatives of (η -cyclopentadienyl-η-methylcyclopentadienyl) titanium (IV)

Summary Pseudohalide complexes of the (-cpL)TiXZ type (where cp = cyclopentadienyl, L = -McCs₅-H₄ and X = N3, NCS, NCO or NCSe) have been prepared in aqueous and nonaqueous media and characterized by elemental analyses, i.r. and n.m.r. spectroscopy. I.r. spectroscopy shows that NCS, NCO and NCSe are bonded to the titanium atom through nitrogen in these complexes which are thus true isothiocyanato, isocyanato and isoselenocyanato derivatives respectively.