Numerical Simulation of Response of SRC Columns Subjected to Blast Loading

The dynamic characteristics and failure modes of steel reinforced concrete (SRC) columns subjected to blast loading are complicated because of the transient stress wave in the SRC columns and the interaction between steel and concrete. This paper presents a numerical simulation of the response of SRC columns subjected to blast loading using hydrocode LS-DYNA. In the numerical model, a sophisticate concrete material model (the Concrete Damage Model) is employed with consideration of the strain rate effect and the damage accumulation. An erosion technique is adopted to model the spalling process of concrete. The possible failure modes of SRC columns are evaluated. It is observed that the failure of SRC columns subjected to blast load can generally be classified into three modes, namely, a direct failure in concrete body due to the stress wave, a transverse shear failure near the support sections due to the high shear force, and a flexural failure pertaining to large local and global deformation of the reinforcing steel.     

校园网教务管理信息系统设计初步

教务管理工作一直是高校管理的重点 ,本文根据本校校园网的特点 ,结合教务工作的实践 ,探讨了校园网教务管理系统的具体设计思想     

近代中国乡村社会权势关系演变——以刘文彩与袍哥为个案

在中国近代社会中,国家、地主、农民三者之间是一种三角关系。从理论上讲,只有三者维持一种相对平衡状态,农民生活才会稳定,社会经济才会继续发展。但通常情况下,地主阶级具有贪婪的剥削本性,总是千方百计地兼并小农土地,转嫁赋税负担。如果国家有一定的远见和力量,就会适当抑制地主的兼并,保护农民的利益。当国家已无力保护小农或者根本不打算保护小农时,农民起义就会爆发,在有先进阶级及其政党领导的情况下,最终将导致一个旧社会的灭亡和新社会的产生。从川西袍哥地主刘文彩的个案上就能看到这一点。     

Deterministic and randomized scheduling problems under the lp norm on two identical machines

Parallel machine scheduling problems, which are important discrete optimization problems, may occur in many applications. For example, load balancing in network communication channel assignment, parallel processing in large-size computing, task arrangement in flexible manufacturing systems, etc., are multiprocessor scheduling problem. In the traditional parallel machine scheduling problems, it is assumed that the problems are considered in offline or online environment. But in practice, problems are often not really offline or online but somehow in-between. This means that, with respect to the online problem, some further information about the tasks is available, which allows the improvement of the performance of the best possible algorithms. Problems of this class are called semi-online ones. In this paper, the semi-online problem P2|decr|lp (p＞1) is considered where jobs come in non-increasing order of their processing times and the objective is to minimize the sum of the lp norm of every machine's load. It is shown that LS algorithm is optimal for any lp norm, which extends the results known in the literature. Furthermore, randomized lower bounds for the problems P2|online|lp and P2|decr|lp are presented.     

Active changes of lignification-related enzymes in pepper response to Glomus intraradices and/or Phytophthora capsici

INTRODUCTION Plants have defense mechanisms against patho-gen infection by inducing systemic resistance in re-sponse to localized pretreatment with biological cotrol agents, thus making them resistant to subsequpathogen infection (Caruso et al., 1999; Hammschmidt, 1999; Mohammadi and Kazemi, 2002; yada et al., 1995; Pozo et al., 2002; Ray et al., 199Biological control of plant pathogens has receivmuch more attention. It is well known that plants amicroorganisms symbiosis is a defense m…     

职业教育应转变教学模式

目前的职业学校教学模式仍然是传递——接受教学模式。职业学校要转变教学模式,在教学管理中贯彻以人为本的原则。职业学校教学模式的改革方向是“主导——主体论”教学模式。     

从废八股到改科举:以1898年的争论为中心

科举制度在中国封建历史进程中曾经起过重要的作用，但是久而久之积弊难返。由于这一制度的任何更改都势必牵涉众多乃至一代人的利益，因此多年来议论归议论，执行归执行，人人都说科举制度摧残人才，不利于选拔人才，可是人人也都在这条，艮难的道路上跋涉。到了1898年夏天，由于政治变革的急剧发展．废除以八股取士为主要内容的科举制度也就自然地提到了政治日程。以康、梁为代表的维新派坚决主张彻底废除科举考试制度，甚至建议光绪皇帝不惜采取某些非常规的政治手段。在维新势力的鼓吹和支持下，光绪帝冒然宣布废科举，然而由此却引发了一场空前的辨难和新旧势力的急剧冲突，最后清廷只好采取变通的办法从废科举的既定政策退回到改科举。     

论高校后勤社会化在高等教育产业化中的作用

揭示高校后勤社会化的内涵需要一定的前提条件，社会主义市场经济对后勤社会化改革的深刻影响往往是通过高等教育产业化的具体要求来实现。高校后勤社会化在高等教育产业化中的作用亦成了探讨的一个重点。     

PLC在交通信号灯控制系统中的应用分析

以交通信号灯控制系统为例阐述了PLC的编程方法 ,并通过仿真给出了结果。     

关于人才强国战略的几点思考

知识经济赋予人才强国战略的必然性体现在：知识经济产生的根源凸显了智能资源的重要性，人才是知识经济运行的核心。建构与实施人才强国战略的理论价值，体现在建构人的全面发展理论在社会主义初级阶段的实践观念，有利于完善社会主义现代化宏观战略的科学体系，其实践价值体现在彰显人的创造性，实现人的现代化，指导人才的培养、开发与使用。人才强国战略的建构与实施必须坚持创新原则，必须解放思想，更新观念，而相关的具体制度创新是关键。