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131.
球状地球体可控深度电法的效应系数可近似地全面表达可控深度电法和各种效应。通过点源二度体的电算模拟实验,证明了该方法在水平柱状体和地下存在电阻率垂直界面的条件下,也是有效的。  相似文献   
132.
A pseudodynamic testing procedure has been applied by which the seismic response of a base‐isolated building is obtained by using as specimen the isolators, while the superstructure is numerically simulated. The procedure also takes advantage of the continuous pseudodynamic testing capabilities of the ELSA laboratory, which increase the accuracy of the results and reduce the strain‐rate effect of the rubber bearings. A simple proportional correction of the measured forces compensates the remaining strain‐rate effect due to the unrealistic speed of the test. The correction factor is obtained by means of a characterizing test on the specific rubber isolators. The developed method has been successfully applied to the prediction of the seismic response of a base‐isolated four‐storey building submitted to several specified accelerograms. The results for those earthquakes as well as the effects of some changes of the parameters of the system are discussed. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   
133.
十万山盆地位于广西西南部,大地构造位置属于华南板块的西北缘,是在华南板块与杨子板块拼接的加里东运动之后,早古生代华南洋再一次打开形成被动大陆边缘。晚二叠世末,该地区变成孤后盆地,进一步转化成前陆盆地。在盆山转换过程中,经历了三次沉积-构造盆山转换过程:泥盆纪-二早叠世分地新生与被动大陆边缘拉张裂谷;晚二叠世与中三叠世间盆地构造性质转换与前陆盆地;晚三叠世至侏罗纪的晚期前陆磨拉石沉积。在碎屑岩陆架沉积阶段,生成碎屑岩烃源岩层。在碳酸盐台地沉阶段,发育硝屑灰岩、藻灰岩、礁灰岩和暴露作用生成的白云岩储集岩。因而其早期被动大陆边缘阶段构了古生新储组合。前陆盆地早期在前渊盆地内沉积了一套碎屑岩烃源岩。它与早期的储集层构成了新生古储组合。同时也对下伏地层起到了封闭作用。沉积地层逐层向克拉通斜坡上超覆,发育地层圈闭。前渊阶段中期快速沉积的巨厚的复理石沉积和晚期快速沉积形成的磨拉石沉积有利于早期沉积的迅速埋藏、成熟和保存。  相似文献   
134.
硅酸盐细菌解钾作用机理的综合效应   总被引:44,自引:5,他引:44  
硅酸盐细菌能释放土壤含钾硅酸盐矿物中的磷、钾、硅等元素,直接供给植物生长利用,同时亦具有固氮能力。这为挖掘土壤潜在肥力、发展可持续农业提供了一条新的思路。本文分析了硅酸盐细菌对钾长石、伊利石的解钾作用过程,细菌-矿物复合体的形成,细菌对矿物的溶蚀作用,矿物晶体结构与细菌的解钾作用关系,复合体微环境的变化对细菌解钾作用的影响以及细菌对K^ 的主动吸收等,从微生物矿物学的角度讨论了硅酸盐细菌对含钾硅酸盐矿物解钾作用的机理问题,提出了硅酸盐细菌解钾作用综合效应的看法,并就农业生产上的利用问题指出,应根据当地的土壤环境,选择适宜的生产菌种和吸附剂,并配合使用其它化学肥料和有机肥料。  相似文献   
135.
In this paper it is argued that the re-establishment of a metropolitan government in the Greater Copenhagen Area in 2000 (Greater Copenhagen Authority) is not to be seen as a return to the kind of regional, coordinative authority (Greater Copenhagen Council) that was abolished in the Thatcherite climate of the 1980s. Throughout the 1980s and 1990s new forms of urban governance, entrepreneurialism and a higher national priority to the capital region were introduced, which changed the conditions under which the new metropolitan government is operating. This `contextualization' of the analysis of the two generations of metropolitan government points to the fact that typologies of metropolitan government, such as the one put forward by Sharpe (1995), often lacks analytical cogency. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   
136.
Traditional models of urban development are no longer adequate to describe current metropolitan transformations. These are now at the centre of a debate concerning management and administration. In Italy, delays in resolving problems of urban and metropolitan government, despite the legal framework provided by Law 142/90, have weighed heavily on the larger urban areas of the country: Rome, Naples, Milan, which have not been able to tackle the issue of metropolitan government. Recent legislation, while not providing a pre-defined institutional solution, allows separate administrative districts to collectively establish metropolitan institutions of `variable geometry'. The Milan urban area is not one city, but a system of mutually-dependent cities, linked to each other and the rest of the world by a transport network still requiring much investment. The vitality of its economic structure (especially its small firms) is held back by seriously inadequate infrastructure and low external economic efficiency. The provincial capital may boast `historic centrality' but the most interesting potential for development is to be found on the periphery and in the administrative districts immediately surrounding it, in the recovery of derelict industrial areas and dormitory towns established in the 1950s and 1960s, especially to the north. Recovery of derelict areas, green areas, and better transport links within the urban area and with the outside world are the key elements in the reorganization of `Greater Milan'. In this situation of rapid transformation the most appropriate political strategies involve negotiated planning. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   
137.
There are four types of metamorphic rocks in the Marinwobo fault, i. e, cataclasite, mylonite,mictosite and migmatitic granite, and the formation of these rocks is due to the progressive metamorphism of the pyroclastics. The fluids play a very important role in the metamorphic process of these rocks in the Marinwobo fault, the most important feature is that the fluids not only result in the migration of the major elements of the deformation rocks, but also result in the volume loss of the deformation rocks in the deformation process. Thus the migration laws of the major elements in different stages of the progressive metamorphic process are discussed according to mass balance equations. Finally, the quantitative analysis of the mass loss and volume loss of the different rocks the in Marinwobo fault is discussed in this paper.  相似文献   
138.
Based on the mineral and chemical compositions of spoils taken from the Shilu Cu-Mo deposit and Hetai gold deposit, the leaching and batch experiments were made on spoils taken from these two deposits using the leaching column designed by the authors. The experimental results showed that it is not always true that the mine drainage is acidic. Its acidity depends on acid-buffering capacity of gangue, host rock and its alteration mineral assemblage. The composition of the drainage water is related with the interaction between superficial or underground water and solid materials in the spoils, including minerals, hydroxides and amorphous substances. The leaching extent of the element is related with its occurrence form in the deposit. The preferential flow results in leaching-out of heavy metals in large amounts. So it is important to prevent the generating of preferential flow in the system. The results will provide very important grounds for the comprehensive management of land and ecological rehabilitation of the mine site.  相似文献   
139.
可调滞回模型的磁流变阻尼器及其试验   总被引:5,自引:0,他引:5  
本文在现在磁流变阴尼器性能研究的基础上,提出了可调滞回模型的磁流变阻尼器及其试验方法,并进行理论、试验及算例分析。首先,根据恒定电流下磁流变阻尼器的阻尼力滞力特性,利用磁流变材料特性的电流(即磁场)可控特点,建立了变电流下的阻尼力滞回模型;其次,在中通过电路板控制外加电流与装置变形间的函数关系,实现了变电流调节的阻尼力滞回模型;最后,将磁流变阻尼器与橡胶隔震装置结合,形成智能磁流变隔夺装置,并对一个单自由度隔震结构进行了数值仿真分析。  相似文献   
140.
通过对中原地区1500年-2000年所有19次M≥6级地震后空间图像的分析,初步认为M≥6级地震发生后平均63年内,在距原震中平均176km内无M≥5级地震发生,全部19次震例均呈现出内部减震效应,而在其外围出现地震增强的活动图像特征,增震效应对应率为72%。这种强震后的减(增)震效应,不仅对地震危险性分析,而且对1年尺度以上的地震趋势预测均有一定的意义。  相似文献   
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