g-factor anisotropy for donor-bound electrons at all magnetic fields

Summary A theory of theg-factor for electrons bound to donors in zincblende semiconductors is presented for all magnetic fields. Simple analytical expressions are obtained for weak, intermediate and high magnetic-field intensities. A comparison between theory and the experimental result in the case of InSb is made.     

Industrial multi-stage continuous filtration process: influence of operating parameters

This paper presents a theoretical study of the effects of operating parameters on the behaviour of an industrial crossflow filtration unit. A continuous three stage unit and its application to yeast cell harvesting are considered. A model of standard industrial processing is developed, and the influence of dead volumes, start-up procedure, crossflow and permeation velocities and maximum transmembrane pressure are investigated. Concentration factors are discussed with respect to the effects due to dead volumes.     

Multielemental characterisation of cobalt by glow discharge quadrupole mass spectrometry

Multielemental determination and the assessment of purity of cobalt metal used in the preparation of Ni-based super-alloys have been carried out by glow discharge quadrupole mass spectrometry (GD-QMS). Relative sensitivity factors (RSF) generated from certified iron matrix reference samples (NIST 663 and 664 low alloy steel pin standards) could be used for the determination of different trace element constituents of the sample. Different wet chemical procedures were also carried out for the determination of the trace constituents in the sample. The GD-QMS results are in reasonably good agreement with those obtained from wet chemical procedures, validating the use of the RSF values generated on low alloy steel standards for the computation of trace element concentrations in cobalt metal. A variety of molecular ions formed through the reaction of cobalt (matrix) with the discharge gas (argon) were also detected.     

Simple evaluation of Franck–Condon factors and non‐Condon effects in the Morse potential

The calculation of Franck–Condon factors between different 1‐D Morse potential eigenstates using a formula derived from the Wigner function is discussed. Our numerical calculations using a simple program written in Mathematica are compared with other calculations. We show that our results have a similar accuracy as those calculations performed with more sophisticated methods. We discuss the extension of our method to include non‐Condon effects in the calculation. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem 88: 280–295, 2002     

QSPR Modeling of the Reactivity Parameters of Monomers in Radical Copolymerizations

For a series of monomers, QSPR test analysis is performed by optimizing the correlation weights of the local invariants of molecular graphs representing monomer structures in order to construct models of the reactivity parameters of monomers Q and e. This approach may be used as a tool in reactivity predictions for monomers for which no experimental data on Q and e are available.Original Russian Text Copyright © 2004 by A. A. Toropov, V. O. Kudyshkin, N. L. Voropaeva, I. N. Ruban, and S. Sh. Rashidova__________Translated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 6, pp. 994–998, November–December, 2004.     

醌类化合物的超临界流体萃取研究进展

综述了国内近20年来超临界流体萃取技术应用于醌类化合物分离的研究进展,重点介绍了超临界流体萃取技术在中草药中醌类化合物的分析测定方面的应用,分析了影响醌类成分提取效果的主要因素,优化萃取温度和萃取压力能够改善琨类化合物的分离效果,夹带剂的使用则有效地提高了超临界流体的萃取能力。     

原子结构参数的改进Xa法计算

六十年代后期,在Hartree－Fock-Slater法的基础上,提出了Xα法［1］．用于原子结构计算的Xα法与HF（Hartree－Fock）法的主要区别在于：用简单的统计平均交换势替代了HF法中计算最为困难的电子交换势,从而在保持较高理论严谨性和计算精确度的同时,大大减少了计算工作量,近年来获得了广泛的应用．我们尝试用经过适当修改的Xα方法,计算原子参数,解决分子结构中的某些问题．用原子参数解决分子问题,历来是化学和物理工作者常用的方法．本工作的意图是引入一个比HF法简单的容易在微机上实现的某种表现原子参数的计算方法,提供…     

Elucidating dominant factors of PO43-, Cd2+ and nitrobenzene removal by biochar: A comparative investigation based on distinguishable biochars

Four distinct biochars were employed to remove three typical pollutants, meanwhile, path analysis, a multi-statistical regression method, was performed to elucidate the dominant factors of biochar adsorption. This work can provide a new insight to prepare a targeted biochar as adsorbents.     

Fraktionierte Kristallisation von Ammonium- und Magnesiumdoppelnitraten der Ceriterden; Bestimmung der Trennfaktoren und Vergleich der Trennwirkung

Summary The Separation Factors for Pr/La, Nd/Pr, and Sm/Nd, characterizing the crystallization of ammonium and magnesium double nitrates under practical conditions, were determined analytically and are discussed. They confirm that La and Pr can be separated better by fractional crystallization of ammonium double nitrates, whereas in the presence of Sm the magnesium double nitrates are preferable.