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381.
运用电子探针和显微Fourier变换红外光谱技术,对新疆西天山3个榴辉岩样品中的石榴石进行了详细的主量元素和结构水分析。结果显示,石榴石发育以核部富锰铝榴石组分、边部富镁铝榴石组分进变质作用的成分环带。石榴石中OH^-1分布也具有规律:核部→边缘。其结构水OH^-1逐步增加,即从核部的89-239ppm增加到边部的367-658ppm;与石榴石边部相比,石榴石的核部含有较低的OH^-1,却含有较高的H2O和Mn含量。这表明,在蓝片岩向榴辉岩进变质作用过程中,含水矿物脱水反应而释放出大量的分子水,这部分水促进了高压变质反应,形成榴辉岩相矿物,石榴石核部的结晶就是在富水和Mn的条件下进行的。随着高压变质作用的继续,石榴石核部的分子水逐步失水而进入石榴石晶格,形成结构水。因此,在高压变质作用过程中,OH^-1演化实际上是一个由内部不平衡逐步向平衡转变过程。P588.348 相似文献
382.
383.
Limo TANG Shanghong ZHANG Mingzhong YU Xingkui WANG 《国际泥沙研究》2006,21(4):272-280
1 INTRODUCTION The mechanism of particle movement in the flow is one of basic problems of sediment transport research. The conventional measurement approaches usually disturb the structure of the flow, consequently inducing errors. With the development of… 相似文献
384.
Grain-size features of a Miocene loess-soil sequence at Qinan: Implications on its origin 总被引:4,自引:0,他引:4
QIAO Yansong GUO Zhengtang HAO Qingzhen YIN Qiuzhen YUAN Baoyin LIU Tungsheng 《中国科学D辑(英文版)》2006,49(7):731-738
In northern China, the Quaternary loess-soil se-quences[1] and the Hipparion Red-Earth Formation in the eastern Loess Plateau[2―6] provide a continental climate record for the past 8 Ma. The recently reported Miocene[7] and Pliocene[8] loess-soil sequences near Qinan constitute an eolian record of the western Loess Plateau from 22 to 3.5 Ma. Earlier studies[9] place the Miocene loess deposits into the so-called Gansu Sys-tem. Our investigations show that the Gansu System contains inde… 相似文献
385.
Gradient theory (GT), a form of density functional theory (DFT), was applied to water, methanol, and ethanol using the cubic perturbed hard body (CPHB) equation of state (EOS). Compared to the standard form of classical nucleation theory (CNT), the GT results for water showed an improved temperature dependence, but the supersaturation dependence was slightly poorer. GT and several forms of CNT were also found to be in good agreement with a single high T molecular dynamics rate for TIP4P water. The rates predicted by GT for methanol and ethanol were improved by several orders of magnitude compared to CNT, but no improvement in the predicted temperature dependence of the rates was found. 相似文献
386.
INTRODUCTIONEarthquake induced byreservoir is a kind of crust motion andis an outcome of the joint functionof current crustal movement andreservoir storage .The cause of reservoir-induced earthquakesincludesthe decrease of strengthand elasticity modulus of rockonthe one hand,andthe decrease of friction offault surface because of water permeation onthe other .The more large-scale reservoirs built ,the more reservoir-induced earthquakes will happen.As iswell known,reservoir-induced earthqua… 相似文献
387.
骑马沟铅锌矿赋存于熊耳群条纹状硅质大理岩与火山凝灰岩之间.通过对矿床地质、岩石、矿物组合特征等方面的初步研究,认为该矿床为热水沉积-热液改造成因铅锌矿床,其成矿主要与熊耳期火山岩及火山气液作用有关.这是在河南熊耳群火山岩中首次发现的该类矿床类型. 相似文献
388.
Eric Gutierrez 《Geoforum》2007,38(5):886-900
Meeting Millennium Development Goals on water and sanitation services in developing countries are fraught with difficulties, as can be seen most clearly from the experiences of Malawi and Zambia, two of the world’s poorest countries that have committed to meeting these goals. The challenges are not only technical, requiring programmatic or engineering solutions, but are also and most importantly political, because solutions will most often cause a rearrangement of the peculiar forms of power relations that have emerged within institutional and political environments of the two countries. The challenges include weak state support for water and sanitation provision, unreliable and contested indicators of coverage, poor sectoral co-ordination, and fragmented donor efforts. This field note examines these challenges in greater detail to cast new light as well as draw attention to possible solutions that can be implemented. 相似文献
389.
For nearly a decade the La Paz-El Alto concession in Bolivia was heralded by donor organizations, the state and the commercial water industry alike as an emblematic ‘pro-poor’ water concession under the private sector model. Managed by one of the largest water multinationals in the world (the French company Suez), the network was extended beyond the new connections required by the original ‘pro-poor’ contract, acclaimed as a pioneer of new pro-poor technologies and frequently disseminated internationally as an example of best practice. This paper analyses the La Paz-El Alto concession’s pro-poor image focusing on issues of social exclusion and network extension, contract negotiation, participation and transparency. It documents the rise of social protest about the concession and critiques the failure of neoliberal regulatory systems to promote accountability to the poor. In the context of the continued transnationalisation of the water industry the paper highlights the need for new mechanisms and delivery models to ensure greater national control over private companies and the development of a framework for international water governance. 相似文献
390.
本文着重论述了上庄坪铜铅锌多金属矿床的地质特征和成矿淀化,进行了成因分析。认为含矿岩系的物源主要来自海底火山喷发作用形成的黄铁矿化矿源层。经燕山期构造热液的叠加,驱使矿源层中的成矿元素活化、迁移,在有利的构造部位富集成矿。 相似文献