岷江上游森林水文效应研究

本文提出了用一般性流域水文模型研究森林水文效应的途径。得出在岷江上游地区随着覆盖率的下降年径流量减少、径流成份改变、年风分配更趋不均匀和洪峰流量增大的结论。在此基础上，预测了岷江上游地区水源涵养林建设的水文效益与前景。     

基于模糊值损益证券的期望效用优化分析

对由具有模糊值损益证券所构成市场中的期望效用优化问题进行了分析.在分析中使用了加权期望效用模型度量模糊值财富对应的期望效用,提出了模糊意义下的套利概念,证明了最优投资组合存在当且仅当市场不存在模糊意义下的套利机会,重点讨论了最优投资组合的性质,并利用最优组合描述了资产的当前价格.     

Water and the entrepreneurial city: The territorial expansion of public utility companies from Colombia and the Netherlands

Since the mid-1980s, liberalization has motivated numerous water supply reforms. Among these, privatization has received the most attention. Yet, its actual scope has been limited. Beyond privatization, the territorial expansion of municipally owned water corporations into new service areas can be witnessed in countries as diverse as Italy, South Africa, Canada, Colombia and the Netherlands. Generally, the activities of public water corporations are analyzed through the lens of commercialization. This framework is central to understanding recent shifts in water supply. Yet, while it addresses the effects of commercialization on service quality and access, it rarely integrates the influence of shifts in social reproduction and collective consumption in structuring reform. Drawing on theories of urban entrepreneurialism, I attempt to advance a broader analytical framework that is more amenable to integrating the diversity of processes involved, including but not limited to commercialization. At the same time, the territorial expansion of municipally owned water corporations suggests ways to rethink urban entrepreneurialism: it is not only commercial, it is also social, and it is Schumpeterian. To make these points, this article examines the efforts of two public water corporations to go international: EPM of Medellín, Colombia and WMD of Drenthe, the Netherlands.     

联合效用理论与风险量化的防波堤决策模型研究

回顾和总结了当前防波堤项目的决策模型,介绍了效用理论的起源、发展和理论基础,提出了效用理论结合防波堤风险量化方法的新型风险决策模型.以某直立式防波堤的优化设计为例,将防波堤滑移失效概率、防波堤尺度、生命周期内的风险损失和预期收益、决策者风险态度等量化指标纳入决策系统,比较了费用最小化、费用-收益权衡和效用三种决策模型,探讨了优化设计重现期的确定.结果表明,决策者的风险态度将极大地影响防波堤方案的选择,而费用-收益模型实质上是效用模型的一种特殊情况,这凸显了效用模型的包容性和合理性.     

住宅抗震的维修准则与效用决策

研究了住宅抗震的预防性,恢复性,改造性维修准则和震后拆除重建准则,分析了住宅抗工程的效用特性,提出了住宅震维修项目效用决策准则,建立了住宅抗震维修项目效用评价指标系统与评价模型。     

考虑接缝影响的地下综合管廊振动台模型试验

地下综合管廊属于浅埋狭长型结构，变形缝存在较为普遍，而在地震荷载作用下，其会对地下结构的振动响应产生一定影响，但是目前针对该问题的研究却十分有限。基于振动台模型试验并考虑接缝的影响，开展了不同波形、不同峰值加速度地震波激励下的综合管廊地震响应特征研究，对场地加速度、动土压力以及管廊结构加速度、位移、动应变和弯矩等响应进行了测试和分析。试验结果表明：管廊振动主要受周边土体影响，接缝截面边墙在地震过程中与土体发生脱离，但管廊结构整体性保持良好；管廊接缝在强震下位移较小，不会发生大变形破坏；强震作用下动土压力分布呈非线性特征；接缝截面在地震中受到的弯矩作用小于中部截面，对抗震性能有利。     

实验曲线的自动拟合

本文介绍了一个能用最小二乘法原理自动地回归一个一元线性方程或一元非线性方程的程序 如果将一组实验数据[(x_i,v_i),i=1,2,…,n]送入计算机内,该程序将自动地从下列给定的方程中选出一个最佳的回归方程: 1、y=a+bx, 2、y=ax~b, 3、y=ae~(bx), 4、y=a+blgx, 5、y=ae~(b/x), 6、1/y=a+b/x, 7、y=1/(ax+b), 8、y=1/(a+be~(-x)), 9、y=ax~+C, 10、y=ae~(bx)+C。     

Applying Four Different Risk Models in Local Ore Selection

Given the uncertainty in grade at a mine location, a financially risk-averse decision-maker may prefer to incorporate this uncertainty into the ore selection process. A FORTRAN program risksel is presented to calculate local risk-adjusted optimal ore selections using a negative exponential utility function and three dominance models: mean-variance, mean-downside risk, and stochastic dominance. All four methods are demonstrated in a grade control environment. In the case study, optimal selections range with the magnitude of financial risk that a decision-maker is prepared to accept. Except for the stochastic dominance method, the risk models reassign material from higher cost to lower cost processing options as the aversion to financial risk increases. The stochastic dominance model usually was unable to determine the optimal local selection.     

反应位移法在地下综合管廊抗震设计中的应用

为探讨反应位移法在地下综合管廊地震分析中的适用性及地基弹簧刚度选取和模拟方法,采用SAP2000结构有限元软件进行地下结构地震反应分析,研究基床系数、地层剪应力计算方法对结构地震响应的影响,并与PLAXIS软件的动力时程分析结果进行对比分析。结果表明：反应位移法在地下综合管廊的初步抗震计算中可优先选用;在地基弹簧刚度计算方法中,推荐使用日本公式法和常规静力有限元法,并尽量考虑土层分层情况,若一味作均匀等效化,可能导致土体动剪切模量偏大,土层均质等效计算的结构内力值与动力时程法的结构内力偏差达到-400%~-250%;建议采用SAP2000程序中实现仅受压行为的两节点缝单元+远端固定铰支座相结合的方法模拟法向地基弹簧,采用常规土弹簧单元模拟切向地基单元。     

水安全与河南经济可持续发展

文章阐述了水安全的概念及其对可持续发展的意义,分析了河南省水资源利用现状及存在的问题,在此基础上依据可持续发展的要求,提出了重整用水系统、加强水资源统一管理、建立节水型社会等,符合河南省经济社会可持续发展要求的新型水资源利用模式。