关于阶乘多项式

本文概括叙述阶乘多项式的某些性质,推导了阶乘多项式差分的Telescopeing Sums和Summation by Parts公式,并给出在解差分方程、级数求和及概率论中的应用实例。     

不安抗辩与预期违约刍议

源自英美法系和大陆法系的预期违约与不安抗辩权制度在我国合同法中首次予以移植并进行了发展,这是两个相当重要而又最容易混淆的的概念和制度,全面分析并予以把握,对司法实践和理论教学都有十分重要的意义。     

新高考模式下的物理教学

近年来，全国高校招生由“3 2”的模式逐步向“3 X”或“3 X 1”方案过渡，新的高考方案考试内容更加注重能力和素质的考查，命题范围遵循教学大纲又不拘泥于教学大纲，试题设计增加应用型和能力型的题目。这就要求我们在传授基础知识、基本技能的同时，着力培养学生的能力，提高学生的综合素质。笔者认为新高考模式下的物理教学应强化和重视以下四个方面的问题。     

Nonlinear modelling of a SOFC stack by improved neural networks identification

The solid oxide fuel cell (SOFC) is a nonlinear system that is hard to model by conventional methods. So far,most existing models are based on conversion laws,which are too complicated to be applied to design a control system. To facilitate a valid control strategy design,this paper tries to avoid the internal complexities and presents a modelling study of SOFC per-formance by using a radial basis function (RBF) neural network based on a genetic algorithm (GA). During the process of mod-elling,the GA aims to optimize the parameters of RBF neural networks and the optimum values are regarded as the initial values of the RBF neural network parameters. The validity and accuracy of modelling are tested by simulations,whose results reveal that it is feasible to establish the model of SOFC stack by using RBF neural networks identification based on the GA. Furthermore,it is possible to design an online controller of a SOFC stack based on this GA-RBF neural network identification model.     

Hydrogen storage properties of ball-milled Mg-based composite with PdCl2 additive

Mg-25 wt% Mg2Ni composite was prepared by sintered method,hydrided at 613 K and then ball-milled with 1.5 wt% PdCl2 additive for 51 h. The effects of PdCl2 on the hydriding and dehydriding behavior of Mg-25 wt% Mg2Ni composite were investigated. The absorption and desorption rate of the composite with PdCl2 is fast and the hydrogen storage capacity is more than that of the composite without PdCl2. The maximum hydrogen storage capacity reached 3.48 wt% at 373 K,and 5.05 wt% H at 453 K,respectively. The improvement of sorption and desorption kinetics is attributed to the catalytic effect of PdCl2,and the grain refining and lattice strain introduced by ball milling.     

论班克斯多元文化课程改革的途径及启示

班克斯多元文化课程改革的途径有四种：贡献途径、附加途径、转换途径和做出决定与采取社会行动的途径，这四种途径对我国当前正在进行的课程改革具有重要的启示意义；课程要体现多元文化的理念；目前的课程向多元文化课程的改革必须要进行结构上的调整，必须能使学生形成多元文化社会所必备的能力、情感态度与价值观，在多元文化课程的实施中，要增加活动课程的比例。     

BEHAVIOR ANALYSIS OF CANTILEVER ARCHED RETAINING STRUCTURES IN FOUNDATION PITS

ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅａｒｃｈｅｄｒｅｔａｉｎｉｎｇｓｔｒｕｃｔｕｒｅ ,ａｎｅｗｔｙｐｅｏｆｒｅｔａｉｎｉｎｇｓｔｒｕｃｔｕｒｅｉｎｆｏｕｎｄａｔｉｏｎｐｉｔｓ(Ｃａｉｅｔａｌ.,1 992 ) ,ｈａｓｍａｎｙｖｉｒｔｕｅｓｓｕｃｈａｓｍｏｒｅｒｅａｓｏｎ ａｂｌｅｓｔｒｕｃｔｕｒｅｓｈａｐｅ ,ｓｍａｌｌｅｒｄｅｆｏｒｍａｔｉｏｎ ,ｌｏｗｅｒｃｏｓｔ,ａｎｄｓｏｏｎ .Ｂｕｔｉｔｈａｓｎｏｔｏｆｔｅｎｂｅｅｎｕｓｅｄｉｎｅｎｇｉｎｅｅｒｉｎｇｂｅｃａｕｓｅｉｔｓａｎａｌｙｓｉｓｍｅｔｈｏｄｉｓｎｏｔｒ…     

评析北约新战略

1999年4月24日,北约成员国华盛顿首脑会议正式通过了美国提出的北约新战略概念.这是一份充分体现了美国在21世纪的战略思想和战略方针的文件,其核心就是美国企图推动北约从欧洲走向全球,由“欧洲警察“变成“世界警察“.它标志着北约冷战后过渡时期的结束,体现了该组织根本性质的变化,即北约已由冷战时期基本上是防御性和地区性的军事集团,转变为扩张性的并带有全球性的军事政治集团.这一发展,势将加强美国在北约的领导地位,强化美国在全球的霸权态势,导致国际局势新的动荡和分化.     

数字电视及其先进应用

简要介绍了数字电视技术及其在多媒体数据广播和交互式电视中的应用。     

茶元头--桎木山"丹霞地貌"的特征与旅游开发构想

邵阳市西郊及附近的“丹霞地貌”具有丹崖峭壁、顶缓坡陡、似人似物、造型奇特的突出特征．位于资水河畔，紧邻邵阳市区，交通方便，开发前景看好．文章认为本区旅游开发市场定位为城郊休闲旅游，并对其旅游开发提出了一些建设性意见．