用条带织构装饰技术研究液晶全芳共聚酯B-N的取向和非取向膜

用条带织构装饰技术研究液晶全芳共聚酯Ｂ—Ｎ的取向和非取向膜董炎明（厦门大学化学系,厦门,３６１００５）关键词共聚芳酯,条带织构,退火,取向膜,微纤全芳共聚酯Ｂ—Ｎ在分子量较高时能出现黑白相间的条带织构［１～５］,但分子量低时由于极易松驰,不能用普通剪...     

Weakly o‐Minimal Expansions of Boolean Algebras

We propose a definition of weak o‐minimality for structures expanding a Boolean algebra. We study this notion, in particular we show that there exist weakly o‐minimal non o‐minimal examples in this setting.     

An oriented coloring of planar graphs with girth at least five

An oriented k-coloring of an oriented graph G is a homomorphism from G to an oriented graph H of order k. We prove that every oriented graph with a maximum average degree less than and girth at least 5 has an oriented chromatic number at most 16. This implies that every oriented planar graph with girth at least 5 has an oriented chromatic number at most 16, that improves the previous known bound of 19 due to Borodin et al. [O.V. Borodin, A.V. Kostochka, J. Nešet?il, A. Raspaud, É. Sopena, On the maximum average degree and the oriented chromatic number of a graph, Discrete Math. 206 (1999) 77-89].     

标准算子代数上完全保对合性的可加映射

刻画了无限维实或复Banach空间上的标准算子代数间完全保对合性的可加映射,证明了这样的映射是同构的常数倍或(复情形下)共轭同构的常数倍.     

磷脂酰胆碱LB单分子膜诱导下KDP晶体取向生长的研究

有机超薄膜诱导晶体生长是在化学、物理与生物多门学科相互交融的基础上发展起来的新兴学科 ,并逐渐成为仿生合成的重要分支 [1] .目前的研究重点主要集中于以有机化合物 LB膜作为模板剂诱导生物矿化材料上 [2～ 5] .磷脂 LB膜是生物膜的简化模型体系 [6 ] ,用它作模板剂将使该领域的研究进一步接近生物体系 .对晶体而言 ,修饰晶体材料的特征对于改善和测定材料的光学性能至关重要 [2 ] ,但目前有关上述领域的研究几乎均是空白 .KH2 PO4 ( KDP)晶体是性能优良的非线性光学材料 [7] ,本文首次以磷脂分子 LB膜作为模板剂诱导 KDP的晶化…     

不动点集最高维分支的维数为n－5的光滑对合

本文给出了的充要条件，进而完全决定了群（ｋ＿ｉ均为奇数）．     

Criss-cross methods: A fresh view on pivot algorithms

Criss-cross methods are pivot algorithms that solve linear programming problems in one phase starting with any basic solution. The first finite criss-cross method was invented by Chang, Terlaky and Wang independently. Unlike the simplex method that follows a monotonic edge path on the feasible region, the trace of a criss-cross method is neither monotonic (with respect to the objective function) nor feasibility preserving. The main purpose of this paper is to present mathematical ideas and proof techniques behind finite criss-cross pivot methods. A recent result on the existence of a short admissible pivot path to an optimal basis is given, indicating shortest pivot paths from any basis might be indeed short for criss-cross type algorithms. The origins and the history of criss-cross methods are also touched upon.     

Stochastic viability of convex sets

We investigate necessary and sufficient conditions for viability of a closed convex set K under weak solutions of a stochastic differential equation. These conditions are expressed in terms of the distance function to K. When in addition the boundary of K is smooth, then our necessary and sufficient conditions reduce to two relations that have to be verified just on the boundary of K.