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Antonella Diana 《Singapore journal of tropical geography》2013,34(1):25-39
This paper discusses the governing of subjects and objects' mobility in the context of trans‐border rice and corn trade on the China‐Laos frontier. It traces the attempts by a group of ethnic Tai Lue traders from China to assert themselves as ‘flexible subjects’ and economically triumphant actors on the Upper Mekong market in the era of economic regionalization. It illustrates how, between 2005 and mid‐2006, the traders' economic success relied on a variety of ‘border strategies’. ‘Border strategies’ include a gender‐balanced organization of trade, the instrumental deployment of trans‐border ethnicity, the appropriation of a Han style of business, the opportunistic reliance on the Chinese administration's ‘regime of graduated mobility’, and the enactment of a ‘war‐machine’ against Lao state agents. Yet, in late 2006, a new wave of state authoritarianism, enmeshed in corporate accumulation processes, inhibited the traders' success. The paper suggests that, unlike what some defenders of globalization and transnational theories maintain, in the age of economic regionalization, the alleged flexibility and increased mobility of subjects and objects across the borders of the Greater Mekong Subregion remain conditional on an unpredictable mechanism of loosening and tightening. This is part of a long‐applied governing pattern of ‘experimentation under hierarchy’ on the Sino‐Lao frontier. 相似文献
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水对硅酸盐岩体系的许多物理-化学行为有着非常重大的影响.具体对部分熔融过程来说,水可以显著地降低熔融温度、改变熔体性质、影响微量元素在固-液相之间的分配.近年来,科学家们就大量水对硅酸盐岩体系的部分熔融过程的影响进行了许多的高压实验,他们主要关注第二临界端点对熔融过程的重要作用:第二临界端点的出现极大地改变着部分熔融过程中的基本相关系.本文主要针对这些高压实验研究做一总结,并对未来研究方向做一初步探讨. 相似文献
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应用了静态沉降实验方法中的移液管法,初步研究了水中常见阳离子对河流中细颗粒泥沙沉速的影响,这些阳离子包括Na+、Ca2+、Mg2+和Al3+等。实验结果表明,阳离子浓度对泥沙沉速的影响可以分为两个阶段:①随着阳离子浓度的增加泥沙沉速也增大;②当离子浓度大于某值时,离子浓度对泥沙沉速的影响不大。在同样离子浓度条件下,离子价态高者影响较大。同时分析了长江和黄河干流中下游河段的水化学特性;分析结果表明,在一般的河水水质的情况下,有必要考虑水中阳离子(主要是Ca2+、Mg2+)对细颗粒泥沙沉速的影响。 相似文献
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在华南暴雨试验中，采用了多种先进的探测系统，不同探测系统采用测量原理不同，资料的时空分辨率及探测精度有差异，为资料的集成带来一定的难度。针对华南暴雨试验的资料，提出多种资料集成和显示方案。多种探测资料的集成处理包括了对资料的预处理、反演、坐标归一化等，并在其基础上建立了互联网上的气象数据动态查询、站网雷达基数据的处理显示系统，利用可以管理和分析大型多维动态复杂数据集的微机可视化系统PC-Vis5D，实现了单部雷达资料、中尺度数值模式输出结果与观测真实数据的动态集成分析显示。 相似文献
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《地震工程与结构动力学》2018,47(7):1591-1609
Within the last decades, simplified methods alternative to dynamic nonlinear analysis have been developed to estimate the seismic performance of structures toward a performance‐oriented design. Considering drift as the main parameter correlated with structural damage, its estimation is of main importance to assess the structural performance. While traditional force‐based design deals with calibrated force reduction factors based on the expected structural ductility, other methods are based on the definition of a viscous damping factor defined as a function of the expected energy dissipated by the structure. An example is the capacity spectrum method. This method can be applied even without any a priori calibration or designer arbitrariness. This allows considering several peculiarities of the seismic behavior of precast structures, which may be influenced by nontraditional hysteresis of connections and members, interaction with the cladding panels, P‐δ effects, etc. The paper aims at verifying the soundness and accuracy of this method through the comparison of its predictions against the results of cyclic and pseudodynamic tests on precast structures, including single‐ and multistory buildings either stiff or flexible, obtained on full‐scale building prototypes tested within the framework of recent research projects (namely, “Precast Structures EC8,” “Safecast,” and “Safecladding”). Two simple methodologies of determination of the equivalent viscous damping from a force‐displacement cycle, based on the dissipated energy in relation to 2 different estimates of the elastic strain energy, are addressed and compared. Comments on the possible use of this procedure for the estimation of the seismic performance of precast structures are provided. 相似文献
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