中学统计与概率教学重点问题探究

随着科学技术的迅猛发展,信息化时代的到来,人们常常需要收集大量的数据,根据所获得的数据提取有价值的信息,作出合理的决策.统计是研究如何合理收集、整理、描述和分析数据的学科,它可以为人们制定决策提供依据,又为人们认识客     

雨林拓荒者

在西双版纳热带植物园有一座名为“树海行”的群雕,站在中间的长者目光坚毅,远眺前方,一群年轻的科研工作者在他的带领下向着密林深处进发,去探寻雨林的秘密。这位长者就是西双版纳热带植物园的创始人—蔡希陶先生。     

电子束非穿透辐照的LLDPE/LDPE/EVA管性能研究

研究了电子束非穿透辐照的LLDPE/LDPE/EVA塑料管性能,包括管壁表层至内层凝胶含量的深度分布和熔融特性等.结果表明,塑料管外层凝胶含量超过60%时,距外表大于电子射程的深层凝胶含量小于0.4%;电子辐照增加了共混物材料之间的相容性;LLDPE/LDPE/EVA塑料管经电子束非穿透辐照后可以用来制造整体具有良好热缩性,而内壁具有良好热熔性的热缩热熔套.     

免耕条件下覆盖作物对微生物生态的影响

冬季种植覆盖作物结合免耕法构成的保护性耕作法,能够提高土壤养分和抑制土壤风蚀．本文主要讨论了免耕条件下覆盖作物对微生物生态的影响,结果显示覆盖作物对微生物活性有显著的促进作用．     

New application to Riccati equation

<正>To seek new infinite sequence of exact solutions to nonlinear evolution equations,this paper gives the formula of nonlinear superposition of the solutions and Backlund transformation of Riccati equation.Based on the tanhfunction expansion method and homogenous balance method,new infinite sequence of exact solutions to Zakharov-Kuznetsov equation,Karamoto-Sivashinsky equation and the set of(2+l)-dimensional asymmetric Nizhnik-Novikov-Veselov equations are obtained with the aid of symbolic computation system Mathematica.The method is of significance to construct infinite sequence exact solutions to other nonlinear evolution equations.     

HAMILTONIAN DECOMPOSITION OF COMPLETE BIPARTITE γ-HYPERGRAPHS

1. IntroductionHypergraphs are most general structure in discrete mathematics. Computer scientistsintroduced the concept of acyclic hypergraphs and proved that acyc1ic hypergraphs are veryuseful in database theory['--']. In [l], a new system of axioms fOr paths, connectivity andcycles of hypergraphs was introduced. In this paper, we wiIl introduce the concepts ofbipartite hypergraphs and Hamiltonian paths and cycles of a hypergraph.Let V be a finite set. n = (V e) is called a hypergraph on …     

绿色化学的兴起及在中国的发展概况

介绍了化学和环境今后革命性变化的新概念——绿色化学,在国外的兴起和中国的发展概况,并对绿色化学的涵义、研究内容、特点和目的进行了阐述．     

温州师院学生经济状况调查与分析

我校自面向全省招生以来,学生现已遍布全省各地,由于各地经济差异使得学生家庭经济状况千差万别,且学生收入渠道又各不相同,所以学生生活有贫富分化的迹象。本文在对学生经济状况进行调查与分析的基础上,提出一些粗浅的想法,旨在为我校引导学生合理消费和贫困生解困工作开辟新的途径。     

关于完备二分图K_(m,n)冠的K—优美性

马克杰先生曾提出猜想 :完备二分图Km ,n的冠是K—优美图 (m≤n ,k≥ 2 ) 本文证明了当k≥m(n r)时 ,此猜想成立 ,并得到了一般情况的结论。     

New exact solitary wave solutions to generalized mKdV equation and generalized Zakharov--Kuzentsov equation

In this paper, based on hyperbolic tanh-function method and homogeneous balance method, and auxiliary equation method, some new exact solitary solutions to the generalized mKdV equation and generalized Zakharov--Kuzentsov equation are constructed by the method of auxiliary equation with function transformation with aid of symbolic computation system Mathematica. The method is of important significance in seeking new exact solutions to the evolution equation with arbitrary nonlinear term.