糖作为EPC合成手性源

近二十年来,有机合成化学有了很大的发展。对于一个复杂分子,化学家们不再满足于消旋体的合成,而是越来越致力于合成光学纯的目标分子。这就是通常所说的对映纯化合物的合成(Enantiomeric Purity Compound,简称EPC),它是当今有机合成注意的焦     

制革工业中的绿色化学与技术

论述了中国制革工业研究和实施绿色化学与技术的重要性。概述了国内外在绿色皮革化学品的开发和应用, 清洁的制革生产以及制革废弃物利用方面的研究成果, 并提出了今后的发展方向。     

癌症与病毒早期诊断的生物传感技术

本文对癌症与病毒早期诊断的生物传感技术进行了探讨, 展望了用于检测DNA、病毒、生物标志物的薄膜生物传感器的研究和应用前景。     

荧光探针技术在高分子科学中的应用

本文从原理及应用两个方面介绍了荧光探针技术在高分子科学中的应用, 讨论了荧光探针化合物的光化学和光物理行为, 以及如何用该技术来研究高分子的结构特征和高分子体系的动态过程问题, 包括利用该技术来研究高分子体系中的分子运动、能量转移和自由体积等重要例证。     

关于广义拟einstein流形

近年来,不少研究都涉及到Ricci张量R_(αβ)能写成的黎曼流形,如[1]—[3]等。当一个黎曼流形(M,α)满足(1),且其中ξ为单位向量时,Adati等称该M为ξ-Einstein流形。显然,这类流形的性质不如Einstein流形。因此,专门研究这类流形的文献还不多见。上述各引文与[5]讨论的均为其特别情形。不难知道,白正国教授在[6]中研究的流形也属于此。为和具有类似于形式(1)的其它相应流形的名称(如“拟脐”,“拟常曲率”等)相一致,作者在[7]中称满足(1)的M为拟Einstein的。并简记为QE(ξ)流形,而称ξ为基本元。在那里,我们得到了这类流形的几何特征和Weyl张量满足的代数特征,并指出了某些QE流形的不存在性。本文的目的则是探讨当(1)中ξ是迷向向量场时相应流形的有关性质。     

Properties of some families of hypergeometric orthogonal polynomials in several variables

Limiting cases are studied of the Koornwinder-Macdonald multivariable generalization of the Askey-Wilson polynomials. We recover recently and not so recently introduced families of hypergeometric orthogonal polynomials in several variables consisting of multivariable Wilson, continuous Hahn and Jacobi type polynomials, respectively. For each class of polynomials we provide systems of difference (or differential) equations, recurrence relations, and expressions for the (squared) norms of the polynomials in question.

     

OU型Markov过程常返性判别的一个充分条件

研究ＯＵ型Ｍａｒｋｏｖ过程的常返、暂留性．给出了判断ＯＵ型Ｍａｒｋｏｖ过程常返的一个简单实用的充分条件，说明了Ｌｅｖｙ过程Ａｔ的暂留性不能必然地导致由它生成的ＯＵ型Ｍａｒｋｏｖ过程的暂留性．     

Recurrence formulas for molecular integrals over Laguerre Gaussian-type functions

Recurrence formulas for overlap, nuclear attraction, and electron-repulsion integrals over Laguerre Gaussian-type functions are presented. They have been derived using compact recurrence relations for homogeneous solid spherical harmonic operators but are rather lengthy as compared to those over Cartesian Gaussian-type functions. © 1998 John Wiley & Sons, Inc. Int J Quant Chem 66 : 273–279, 1998     

Network Dynamics in Elemental Assimilation and Metabolism

Metabolism and physiology frequently follow non-linear rhythmic patterns which are reflected in concepts of homeostasis and circadian rhythms, yet few biomarkers are studied as dynamical systems. For instance, healthy human development depends on the assimilation and metabolism of essential elements, often accompanied by exposures to non-essential elements which may be toxic. In this study, we applied laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) to reconstruct longitudinal exposure profiles of essential and non-essential elements throughout prenatal and early post-natal development. We applied cross-recurrence quantification analysis (CRQA) to characterize dynamics involved in elemental integration, and to construct a graph-theory based analysis of elemental metabolism. Our findings show how exposure to lead, a well-characterized toxicant, perturbs the metabolism of essential elements. In particular, our findings indicate that high levels of lead exposure dysregulate global aspects of metabolic network connectivity. For example, the magnitude of each element’s degree was increased in children exposed to high lead levels. Similarly, high lead exposure yielded discrete effects on specific essential elements, particularly zinc and magnesium, which showed reduced network metrics compared to other elements. In sum, this approach presents a new, systems-based perspective on the dynamics involved in elemental metabolism during critical periods of human development.     

也谈厄米多项式的递推关系

由厄米多项式的母函数出发,推导出厄米多项式的递推关系以及厄米多项式中系数的递推关系.