块体滑落模型实验与三维数值分析

针对岩体边坡块体滑落过程,利用自行研制的变角度空间块体滑落模型平台,开展块体滑落系列实验,并与基于离散元法开发的3DEC程序对岩质边坡进行三维模拟分析,建立关键块体的非连续变形动态分析模型,模拟了块体滑落过程,得到动态位移图,最终得到楔形块体双面滑落与单面滑落的分界角度在40°～50°这个区间,对边坡工程的开挖支护有一定借鉴意义。更多还原     

湖南省小陂流空腹重力坝节理非线性有限元分析

采用荷载转换的非线性迭代计算方法,用迭代解模拟节理真实的应力~变形特性,通过非线性有限元法计算分析湖南省小陂流浆砌石空腹重力坝在不同工况下的应力、位移,得到了其应力、位移矢量图及应力、位移等值线图,进而根据应力、位移特征和应力~应变变化过程对该坝结构安全、裂缝产生的原因和沿坝建基面抗滑稳定性进行分析,为大坝除险加固提供了正确的处理方法和可靠依据。     

水量水质联合配置方案评价指标体系研究

在阐述水量水质联合配置方案评价内涵基础上,给出了水量水质联合配置方案评价操作流程。利用层次分析法构建以经济社会、生态环境、水资源系统为评价准则,以流域缺水率、新增投资额、水功能区个数达标率、生态用水比例、人均水资源量、水资源开发利用程度和万元GDP耗水量为具体指标的方案评价体系。以分区协调性指标和方案公平性指标为核心,在合理确定指标权重的基础上,选取浑太河流域进行评价体系的可行性验证,结果表明,构建的水量水质联合配置方案评价指标体系切实可行。     

三里坪双曲拱坝接触、接缝灌浆施工工艺

为了加强三里坪大坝混凝土与坝肩的结合力, 增强接触面的密实性并防止漏水,对大坝混凝土与坝拱肩岩石之间缝隙进行接触灌浆。同时,为了保证坝体在蓄水运行后的整体性和有效传递应力,在蓄水前用水泥浆对大坝诱导缝进行接缝灌浆。介绍了大坝岸坡接触灌浆与坝体接缝灌浆的具体施工工艺,提出了有针对性的质量控制策略,包括管路埋设、灌浆材料、灌浆压力和灌浆结束标准等控制措施。     

基于水库群联合调度和人工扰动的黄河调水调沙

为减少小浪底水库及下游河段的淤积，通过水库群的联合调度充分利用万家寨、三门峡、小浪底等干流水库汛前蓄水，在小浪底库区人工塑造异重流，加大小浪底水库的排沙量。同时辅以人工的泥沙扰动措施，调整了库尾段不利的淤积形态。利用进入下游河道水流富余的挟沙能力，在黄河下游“二级悬河”及主槽淤积最为严重的卡口河段实施河床泥沙扰动，减轻下游淤积并扩大下游河道的主槽过洪能力。试验取得了预期效果，小浪底库区淤积三角洲冲刷泥沙1.329亿m3，设计淤积平衡纵剖面以上淤积的3850万m3泥沙全部冲刷消除，小浪底库尾淤积形态得到合理调整；下游卡口河段扰起泥沙164.13万m3，扰沙河段的平滩流量增加了510～640m3/s；下游河道利津以上各河段均发生冲刷，小浪底～利津河段共冲刷0.665亿t。说明通过调水调沙塑造适当的水沙过程，可以遏制黄河下游河道形态恶化的趋势。     

城市化进程中的社区建设模式探索——以长沙市咸嘉新村为例

城市化进程中的社区建设问题是当前一大热点问题，其模式选择也备受学术界关注。本文在分析国内外社区建设模式优劣的基础上，以长沙市咸嘉新村为实证研究，围绕社区建设主体之间的利益分配和相互作用展开研究，通过构建社区建设的三方“博弈模型”，探索出了“G—D—P联合建设”的新模式，以期为我国城市化进程中的新型社区的建设与完善，旧有社区和城中村的改造提供可行性方案。     

Y型圆钢管平面内转动刚度分析

通过建立Y型圆钢管节点有限元模型,对Y型圆钢管相贯节点转动刚度进行单参数分析,同时对整个节点转动刚度进行回归分析,得出Y型圆钢管转动刚度的计算公式。     

Contract,cooperation, and performance in international joint ventures

This study examines how contract, cooperation, and performance are associated with one another within international joint ventures (IJVs). We argue that contract and cooperation are not substitutes but complements in relation to IJV performance. An IJV contract provides an institutional framework guiding the course of cooperation, while cooperation overcomes the adaptive limits of contracts. Our analysis of 293 IJVs in a dynamic market demonstrates that previous cooperation bolsters contractual adaptability, which in turn nurtures current cooperation between the same partners. We find that contract completeness and cooperation drive IJV performance both independently and interactively. When contracts are more complete, cooperation contributes more to performance. Contract and cooperation differ in their quadratic effects such that the contribution of contract completeness to performance declines as completeness increases but the contribution of cooperation remains linear. Copyright © 2002 John Wiley & Sons, Ltd.     

民营经济发展与“重新建立个人所有制”

马克思的“重新建立个人所有制”是“联合起来的个人所有制”,是一种公有制,是劳动者个人能完整地享有所有者权益的所有制。在缺乏自主联合条件的社会主义初级阶段,民营经济对公有制经济的发展起促进作用,但还不是在社会共同占有基础上的个人所有制。要在民营经济与国有经济相协调的过程中不断探索公有制的实现形式。     

A Study of Electromagnetic Radiation of Corona Discharge Near 500-Kv Electric Installations

Data on the spectral composition and intensity of electromagnetic radiation of corona discharge are obtained in an experimental study performed on the outdoor switchgear of the Shagol 500-kV substation of the Chelyabinsk Enterprise of Trunk Transmission Grids and under a 500-kV Shagol – Kozyrevo overhead transmission line. The electromagnetic environment on the territory of the 500-kV outdoor switchgear is shown to be determined by narrow-band radiations (harmonics of the frequency of electric supply) and wide-band radiations due to corona discharges of high-voltage sources. This means that the personnel experience the action of a commercial-frequency electric field and electromagnetic radiation of a quite wide range, which is not allowed for by the existing guidelines. It is recommended to continue the study in cooperation with medical institutions in order to create guidelines that would allow for the joint action of commercial-frequency electric field and electromagnetic radiation and for the voltage in the line, the current load, the meteorological situation, and other factors.