Investigation of quantum confinement phenomenon in composition- and diameter-modulated nanowires

The effects of diameter variation as a result of composition modulation along a nanowire on the confined energy states of electrons have been investigated theoretically. Possible confined states have been predicted by examining an effective potential term. Our results indicate that for a given radius of the wire, there exists a critical radius for modulation part below which carriers could not bound to the modulated part. The critical radius increases and reaches a limiting value as wire radius increases, specifying that the bound states could survive even when the radius of modulation decreases below the radius of remaining wire. Also, application of magnetic field could affect the critical radius so that the confinements to the modulated part are suppressed gradually by increasing the field strength, which is a sign of type-I to type-II transitions. Examination of results by the numerically solving the Schrodinger equation confirms the analytical predictions.     

吸光光度法测定络合物组成的又一理论推证

探讨了溶液的吸光度与络合物离解度之间的关系，提出了等摩尔系列法、摩尔比法测定络合物组成的又一证明方法。     

局部组成模型在K+,Na+∥Cl-,SO2-4,NO3--H2O体系中的应用

首次将电解质溶液的局部组成模型用于新疆罗布泊硝酸钾矿所属体系K^ ，Na^ ／／C^-，SO4^2-，NO3^-，H2O五元体系。利用前期研究所获得的盐的活度积、盐-盐作用参数。预测了该体系及其所包含的五个四元体系的溶解度,除五元体系稍有偏差外,其他体系均与文献值符合较好．     

Variational composition of a monotone operator and a linear mapping with applications to elliptic PDEs with singular coefficients

This paper proposes a regularized notion of a composition of a monotone operator with a linear mapping. This new concept, called variational composition, can be shown to be maximal monotone in many cases where the usual composition is not. The two notions coincide, however, whenever the latter is maximal monotone. The utility of the variational composition is demonstrated by applications to subdifferential calculus, theory of measurable multifunctions, and elliptic PDEs with singular coefficients.     

Composition methods in the presence of small parameters

We derive numerical methods for arbitrary small perturbations of exactly solvable differential equations. The methods, based in one instance on Gaussian quadrature, are symplectic if the system is Hamiltonian and are asymptotically more accurate than previously known methods.     

Composition operators acting on holomorphic Sobolev spaces

We study the action of composition operators on Sobolev spaces of analytic functions having fractional derivatives in some weighted Bergman space or Hardy space on the unit disk. Criteria for when such operators are bounded or compact are given. In particular, we find the precise range of orders of fractional derivatives for which all composition operators are bounded on such spaces. Sharp results about boundedness and compactness of a composition operator are also given when the inducing map is polygonal.

     

Every composition operator is (mean) asymptotically Toeplitz

Nazarov and Shapiro recently showed that, while composition operators on the Hardy space H² can only trivially be Toeplitz, or even “Toeplitz plus compact,” it is an interesting problem to determine which of them can be “asymptotically Toeplitz.” I show here that if “asymptotically” is interpreted in, for example, the Cesàro (C,α) sense (α>0), then every composition operator on H² becomes asymptotically Toeplitz.     

MULTISYMPLECTIC COMPOSITION INTEGRATORS OF HIGH ORDER

A composition method for constructing high order multisymplectic integrators is presented in this paper. The basic idea is to apply composition method to both the time and the space directions. We also obtain a general formula for composition method.     

用NMR分析可生物降解的两亲性嵌段共聚物的相对分子质量和组成

凝胶渗透色谱(GPC)法是根据聚合物分子链流体力学体积大小的比较来测定聚合物相对分子质量(以下简称分子量)的,测得的聚合物分子量与聚合物分子链在溶剂中的构象有关[1]。两亲性嵌段共聚物分子链中亲水链段和亲油链段的极性差异很大,几乎在任何溶剂中它们的构象都不相同,因此可