二茂铁在高温热解乙二胺制备CN_x纳米管过程中的催化性能研究

采用高温热解法 ,以二茂铁 乙二胺有机溶剂为前驱液制备CNx 纳米管过程中 ,改变前驱液配比 ,对 86 0℃ ,不同二茂铁含量条件下制备出的CNx 纳米管进行了产量统计、形貌结构观察和拉曼光谱研究。结果显示 :随着前躯液中二茂铁含量的相对增大 ,不但CNx 纳米管产量随之增加 ,而且产物中“竹节状”结构纳米管相对“中空”结构纳米管的比重也增大 ;拉曼光谱结果进一步证实了由于“竹节状”结构CNx 纳米管的含量或比重增加所带来的纳米管样品整体或平均含氮量的升高而导致的样品结晶有序程度的降低。对单独钴粉和二茂铁催化条件下生成CNx 纳米管的形貌观察进一步证实 :二茂铁在热解法制备“竹节状”结构CNx 纳米管过程中的浮动催化作用显著 ,有利于实现含氮量较高、结构均匀的CNx 纳米管的可控制生长。     

Weak Multiplication Modules

In this paper we characterize weak multiplication modules.     

On rank-perfect subclasses of near-bipartite graphs

Shepherd95 proved that the stable set polytopes of near-bipartite graphs are given by constraints associated with the complete join of antiwebs only. For antiwebs, the facet set reduces to rank constraints associated with single antiwebs by Wagler2004. We extend this result to a larger graph class, the complements of fuzzy circular interval graphs, recently introduced in ChudnovskySeymour2004. Received: November 2004 / Revised version: June 2005     

层次分析中广义最小偏差法的性质

广义最小偏差法（GLDM）是层次分析中一种重要的排序方法．本文讨论了广义最小偏差法的性质和灵敏度分析问题．     

Decomposition Methods for Differentiable Optimization Problems over Cartesian Product Sets

This paper presents a unified analysis of decomposition algorithms for continuously differentiable optimization problems defined on Cartesian products of convex feasible sets. The decomposition algorithms are analyzed using the framework of cost approx imation algorithms. A convergence analysis is made for three decomposition algorithms: a sequential algorithm which extends the classical Gauss-Seidel scheme, a synchronized parallel algorithm which extends the Jacobi method, and a partially asynchronous parallel algorithm. The analysis validates inexact computations in both the subproblem and line search phases, and includes convergence rate results. The range of feasible step lengths within each algorithm is shown to have a direct correspondence to the increasing degree of parallelism and asynchronism, and the resulting usage of more outdated information in the algorithms.     

具有奇异值分解性质的代数

设F为一个域,R为一个带有对合的F-代数,如果R上每一个矩阵都有奇异值分解(简称SVD),则称R为一个有SVD性质的F-代数.本文指出:R为一个有SVD性质的F-代数的充要条件是:R同构于R~+,或R~+上二次扩域,或R~+上四元数体((-1,-1)/R~+),其中R~+为R的对称元集合,并且R~+为一个Galois序闭域.     

On the spectra of finite-dimensional quadratic Bose operators

A complete study of the spectrum of a finite-dimensional Bose operator is carried out in the paper. The cases in which the spectrum is discrete or continuous are studied. Translated fromMatematicheskie Zametki, Vol. 61, No. 6, pp. 835–854, June, 1997. Translated by A. M. Chebotarev     

Rank, term rank, and chromatic number

Let G be a graph with a nonempty edge set, and with rank rk(G), term rank Rk(G), and chromatic number χ(G). We characterize Rk(G) as being the maximum number of colors in certain proper colorings of G. In particular, we observe that χ(G)Rk(G), with equality holding if and only if (besides isolated vertices) G is either complete or a star. For a twin-free graph G, we observe the bound and we show that this bound is sharp.     

双线性系统的无反馈解耦线性化

用现代微分几何方法研究了双线性控制系统的解耦线性化问题，给出了一般双线性系统解耦线性化的充分条件及严格双线性系统解耦线性化的充要条件，并举例说明了本文的结论。     

广义分解定理与两个不等式

本文给出了Banach空间广义分解定理的一个初等证明,并利用它来证明两个对称不等式.这是首次在Banach空间获得这样的不等式.