共查询到20条相似文献,搜索用时 89 毫秒
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一是强化规范化操作,落实村庄规划。在规划思想上充分考虑本区域现状,结合地形地貌和风土人情,因地制宜,体现“以人为本”理念。尊重自然,尊重历史文化传统,延续原有村庄特色,保护整体景观。体现生态优先,节约用地的原则。突出重点,强化居住质量。融入周边环境。规划适当超前,倡导和鼓励农民自治,建设要量力而行,先易后难来改造。 相似文献
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涂光炽 《矿物岩石地球化学通报》1986,(4)
矿床文献中常把Hg-Sb,Pb-Zn,W-Sn,Nb-Ta,Cr-Ni并提。好象它们密切共生在一起,都具有工业价值。实际不然。这些成对元素中,只有一种具工业价值,另一种只是共生,而无回收意义。只有Pb、Zn在一个矿床中常都具有工业价值。但是,W-Sn,Nb-Ta,Hg-Sb,Cr-Ni就不一样。几乎所有的Hg矿床都含有微量Sb,所有Sb矿床也都含微量Hg;但是在同一矿床中,Hg、Sb都具备经济价值却极为少数。W-Sn,Nb-Ta,Cr-Ni也是这样。 相似文献
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“先生有道树新风,刻苦学习业务通。 弱冠清华迎秀士,放洋北美进学宫。 荣鹰硕士回国内,创立团体建会功。 五载西域行旅广,化石巨细百箱中。 地质宗师历六十,清华以后校联时。 新型学院生徒广,遍布全国典范施。 科技起飞增产量,工农效益供穿吃。 宾朋聚祝九十寿,各地高足拜业师。”“华北考古收获丰,河西调查展雄风。 蒙新五年历艰苦,龙骨千块立大功。 袁氏珊瑚传后世,水龙二齿南北通。 喜看桃李满天下,祝师长寿敬一盅。” 相似文献
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P. S. Meenu S. Sowmya R. Asha Latha B. S. Shashank D. N. Singh 《Geotechnical and Geological Engineering》2017,35(2):607-614
Dependence of soil suction on factors such as formation of the soil, its particle size, mineralogy, pore-size distribution characteristics, water content, fabric, stress history and presence of salts has been extensively investigated by researchers. However, the influence of the microbial presence and its activity on the soil suction has not yet received researchers’ attention. With this in view, a methodology that facilitates investigation regarding the presence of ‘soil-microbial interface’, which has been termed as ‘bio-geo interface’, has been proposed in this study. Furthermore, the influence of this ‘interface’ on suction characteristics of such soils has also been investigated and the utility of the proposed methodology in addressing such issues, successfully, has been demonstrated. 相似文献
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A. K. Verma R. K. Bajpai T. N. Singh P. K. Narayan Avi Dutt 《Arabian Journal of Geosciences》2011,4(7-8):1173-1188
Conceptual geological repositories are generally used for disposing spent nuclear wastes containing both high and low level of nuclear radiation and heat. Due to its long-lasting effect, it is imperative to analyze its long-term effect on the surrounding rock. Before analyzing radiation and thermal effect, it is important to have structurally stable cavern because designing an opening in rock is a more difficult problem than designing the structure made of steel. Underground rocks are under stress because of the weight of the overlying rock, and in addition, an underground opening will produce a stress concentration and stress relaxation in the surrounding rock. If the induced stress in the surrounding rock exceeds its strength, the opening will fail either by fracturing or by deforming more than the tolerable limit. In this paper, the stability of four different shapes of excavation has been examined for conceptual geological repositories in Indian context. This has been done using equivalent continuum numerical model which has been incorporated in the commercial finite difference code-FLAC-3D. Effects of opening shapes on stress distribution, subsidence of crown and side wall, and their stability have been analyzed and discussed. The validation of FLAC3D software for its applicability in conceptual underground geological repositories has been done with a published literature. 相似文献
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黔西赫章志留纪晚期小莱采贝动物群的发现及其古地理意义 总被引:1,自引:0,他引:1
志留系在黔西的分布范围很小,已知仅限于赫章县境内。赫章的志留系发育不全,由于缺少古生
物证据,其具体时代长期难以肯定。最近在赫章草子坪志留系中发现腕足动物、三叶虫和双壳类化石群。腕足
类研究结果显示,它应属于小莱采贝动物群(Retziella Fauna) 和新建立的Nikiforovaena Retziella组合。该化石层
下伏紫红色泥岩地层。这段近岸、浅水、杂色碎屑岩层在岩性上与滇东曲靖的关底组类同,可部分对比,推测
其时代为罗德洛世晚期(Late Ludlow),但不宜另立新名,仍称关底组为好。在讨论关底组含义之后,笔者赞同
取消岳家山组的意见。对赫章志留系具体时代的确定使对华南志留纪晚期岩相古地理的传统认识得到修正,罗
德洛世晚期的海侵从滇东的曲靖地区扩大到黔西的赫章一带。 相似文献
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响应位移法能够反映软土隧道在地震荷载作用下的动力反应特性,是一种简便实用的隧道抗震设计简化分析方法。以方形截面隧道为例,采用地层-结构整体动力有限元方法,验证了响应位移法的准确性与合理性;为了简化响应位移法的计算过程,基于平面应变假定,采用弹性理论的复变函数方法推导了土弹簧刚度的解析表达式,并与有限元解进行了对比分析。将土弹簧刚度的解析表达式应用到响应位移法的计算中,同时采用地层剪应力及自由场地震反应位移的简化计算模式,将简化后的响应位移法和整体动力有限元法进行了对比分析,验证了简化方法的可行性。 相似文献
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本文根据马剑-下梓州断裂带的基本特征,分析研究了该断裂带的形成和发展过程;同时根据该断裂带两侧已知铀矿化的特征,阐明了马剑-下梓州断裂带对铀成矿的控制作用。在初步查清天姆尖盆地铀成矿地质背景及其形成富大铀矿床若干地质条件的基础上,指出天姆尖地区寻找富大火山岩型铀矿的方向。 相似文献
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粘土矿物对形成过渡带气的催化作用研究 总被引:1,自引:0,他引:1
本文分析了有机质在粘土矿物中的赋存状态,测定了粘土矿物的表面酸、实验模拟了低演化程度的烃源岩及其抽提物干酪根+不同粘土矿物的催化机制、并通过粘土催化醇脱水反应对粘土过渡带有机质成气机理进行了探讨。研究结果表明,过渡带气的形成主要是受蒙脱石粘土矿物的催化所致,其原因是成岩过程中蒙脱石向混层矿物转化在蒙脱石晶间发生大量的铝代硅,因此在粘土表面产生电荷不平衡而形成酸性,井以路易斯酸和布郎酸作用于有机质,使碳-碳键发生断裂以形成气态烃。 相似文献