On the order of singular optimal control problems

In singular optimal control problems, the functional form of the optimal control function is usually determined by solving the algebraic equation which results by successively differentiating the switching function until the control appears explicitly. This process defines the order of the singular problem. Order-related results are developed for singular linear-quadratic problems and for a bilinear example which gives new insights into the relationship between singular problem order and singular are order.Dedicated to R. BellmanThis work was supported by the National Science Foundation under Grant No. ENG-77-16660.     

论高校提高管理水平与人才培养的关系

育人为本,是社会主义大学不可动摇的办学理念,而管理育人则是育人的重要途径和学校德育的重要组成部分.要做好管理育人工作必须转变教师的管理育人观念,提高管理育人素质,科学管理、科学育人.     

等性块段指数法在综采地质条件评价中的应用

从地质角度介绍了等性块段的基本概念、原理及划分方法,阐述了各种指数的地质意义、计算方法和确定原则,并利用这些指数对矿井综采地质条件进行了评价和分类。     

高校素质教育与教练型教师队伍建设

从高等教育的特点出发,分析了当前高校素质教育在认识和实践两个方面存在的主要问题,提出了树立正确的素质教育观念、打造教练型教师队伍、培养学生的创新精神等实施素质教育的对策。     

An effective absorbing boundary algorithm for acoustical wave propagator

In this paper,Berenger's perfectly matched layer(PML)absorbing boundary condition for electromagnetic waves is introduced as the truncation area of the computational domain to absorb one-dimensional acoustic wave for the scheme of acoustical wave propagator(AWP).To guarantee the efficiency of the AWP algorithm,a regulated propagator matrix is derived in the PML medium.Numerical simulations of a Gaussian wave packet propagating in one-dimensional duct are carried out to illustrate the efficiency of the combination of PML and AWP.Compared with the traditional smoothing truncation windows technique of AWP,this scheme shows high computational accuracy in absorbing acoustic wave when the acoustical wave arrives at the computational edges.Optimal coefficients of the PML configurations are also discussed.     

下石家庄水库工程地质条件分析与评价

以下石家庄水库为例,在工程地质勘测所获得资料的基础上,对该水库工程地质条件进行了分析与评价。     

试论竞争情报从业者的人格培养

在市场经济环境下,竞争情报从业者的人格力量愈发重要并日益显现。应该在充分认知竞争情报从业者人格的基础上,从创新精神、价值观念、道德品质、信息伦理等方面强化其人格培养。     

关于电子商务专业人才培养的探讨

随着计算机和互联网络的高速发展,电子商务迅速崛起,同时,它也对我国高校电子商务人才培养模式提出了新的研究课题.本文首先论述了我国电子商务专业人才培养中存在的问题,然后依据电子商务人才培养的三个方向提出了相应的课程设置,最后讨论了实验室建设以及师资建设.     

A new outflow boundary condition

Boundary conditions come from Nature. Therefore these conditions exist at natural boundaries. Often, owing to limitations in computing power and means, large domains are truncated and confined between artificial synthetic boundaries. Then the required boundary conditions there cannot be provided naturally and there is a need to fabricate them by intuition, experience, asymptotic behaviour and numerical experimentation. In this work several kinds of outflow boundary conditions, including essential, natural and free boundar conditions, are evaluated for two flow and heat transfer model problems. A new outflow boundary condition, called hereafter the free boundary condition, is introduced and tested. This free boundary condition is equivalent to extending the validity of the weak form of the governing equations to the synthetic outflow instead of replacing them there with unknown essential or natural boundary conditions. In the limit of zero Reynolds number the free boundary condition minimizes the energy functional among all possible choices of outflow boundary conditions. A review of results from applications of the same boundary conditions to several other flow situations is also presented and discussed.     

不同培养条件对基因工程疫苗菌抗原蛋白表达的影响

基因工程菌的表达条件研究在现代生物高技术产业化的发展中具有重要的意义。影响基因工程菌表达的因素主要有pH值、温度、诱导剂IPTG的浓度、诱导时间等。笔者分别就以上因素对基因工程菌抗原蛋白表达的影响进行了初步研究。在摇床培养条件下，外源基因表达蛋白的最适表达条件为终浓度O．8mmol/L的IPTG，32℃，诱导6h。