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排序方式: 共有139条查询结果,搜索用时 15 毫秒
1.
新构造运动系指晚新生代以来的构造运动,其在天然地震研究、煤田地质与油气勘探、城市建设等领域均具有重要的意义。以淮南顾桥煤矿为研究区,结合区域构造背景和顾桥煤矿的地震地质条件,利用地震解释中的层拉平技术恢复研究区典型剖面的古构造地貌,厘定了各条断层的时空配置关系;结合13块钻孔岩心样品的ESR和热释光年龄,定量分析了断层的发育年代。结果表明:研究区存在新构造运动,且与地震层拉平构造演化预测结论吻合;研究成果对于顾桥煤矿的设计和安全生产的意义。  相似文献   
2.
地下岩溶的发育影响着地面基础工程的安全使用,所以,我们要对岩溶地区发育特征进行全面的了解,以采取相应的措施保证该地区地面建筑的安全。溶洞的空间赋存状态一般是不规则的三维地质体,它的发育与地下水系及该地区的地质构造有紧密联系,造成溶洞的洞室可能含有高阻或低阻填充物,导致溶洞与围岩之间存在物性差异。高密度电阻率法正是利用物...  相似文献   
3.
墨西哥湾“深水地平线”溢油事故处理研究进展   总被引:4,自引:0,他引:4  
2010年4月20日美国墨西哥湾"深水地平线"石油钻井平台发生爆炸,并引发大火,致使大量的原油(~500万桶)在深海(~1 500m)泄露,这场灾难造成了巨大的环境和经济损失,也对石油开采业的发展产生了负面影响。文中综述了此次事故溢出石油的总量,泄露速率以及测量相关数据中所涉及的技术及方法,对进一步研究溢油转移的趋势和转化过程具有指导意义。喷洒了6.6×106 L的消油剂,消油剂可以促使溢油的快速分散,同时也会给海洋生态系统造成一定的影响。该事故对墨西哥湾的植被和海洋生物有不同程度的影响,如沼泽植被、海水中的浮游动/植物、鱼类、贝类、珊瑚虫、迁徙鸟类,甚至是墨西哥湾大型底栖生物。此次溢油事故涉及各种不同的环境情况,为研究石油烃降解菌在溢油转移和降解过程中种群和群落的变化提供了一个独特的机会,消油剂处理过的溢油转化机理以及微生物降解过程中生物表面活性剂的产生与生物标志物以及微生物菌落的变化之间的关系,仍需要进一步的深入研究和探讨。  相似文献   
4.
Study is made on a 45 km-long artificial ecosystem without irrigation in Tengger desert on the basis of long-term ecological monitoring and ecohydrological fundamentals.Changes in water allocation, utilization, cycle and balance patterns in more than 40-year evolution of the soil-plant system are analyzed. The formation of a drought horizon in shrub rhizosphere and its effect, ecohydrological function of the crust and its effect on the soil-plant system change are discussed. Driven by water self-regulation and water stress, the soil-plant system is going to develop towards the steppe desert to ensure more effective use and optimum collocation of water resource.  相似文献   
5.
世界砂岩型铀矿探明资源的分布及特征   总被引:1,自引:0,他引:1  
最新核电发展规划显示未来我国对铀资源的需求很大。长久来看在继续加大国内勘探力度的同时,需尽快了解国外已探明铀资源尤其是砂岩型铀资源的分布,以更好地从全球视角完善我国的铀资源供应链。我国北方砂岩型铀矿大规模勘探始于本世纪初,起点较晚,在实际勘探和研究中也遇到较多难题及困惑。因此与全球同类型矿床的对比研究亟需展开,亦要求首先了解世界各国砂岩型铀矿的分布和基本特征。本文通过大量文献和最新勘探形势的调研整理,对比分析了近年来全球主要产铀国砂岩型铀矿资源量的变化,系统全面地编制了全新的全球和各国(或各大洲)已发现砂岩型铀矿床及其容矿层位分布图,总体可较精细地反映迄今全球各国已探明砂岩型铀矿分布面貌的现状,同时提炼了重点矿床的主要地质特征。最后总结出全球已发现砂岩型铀矿时空分布具有五大特征:(1)全球分布广泛但不均衡,跨欧亚存在东西向巨型铀矿带;(2)规模因地而异、(超)大型矿床较多;(3)平面分布与气候环境耦合明显;(4)容矿层时代跨度长、成矿时间相对较晚;(5)主要赋存于含油气或聚煤能源盆地中。本文提供了一份可以快速了解和全面把握全球砂岩型铀资源分布及其重要地质特征的材料,为科研人员提供可对比研究的国外矿床实例,同时也为我国企业"走出去"和"走向哪里"提供科学依据。  相似文献   
6.
The action of organisms in shaping landforms is increasingly recognized; the field of biogeomorphology and the conceptual framework of ecosystem engineering have arisen in response to the need for integrated studies of the interactions between biotic and abiotic components of landscapes. Pathways by which organisms influence landscape development may be complex. For example, primary change initiated by one biotic element may initiate a cascade of other changes that eventually produce a significant landscape modification. Mound‐like landforms in North America and southern Africa are widely cited examples of biogenic structures, yet there is considerable controversy regarding the processes responsible for their formation. Heuweltjies (Afrikaans for little hills) are circular mounds ranging from 10–30 m diameter and 0.5–2 m height and are widespread in western South Africa. Colonies of the termite (Microhodotermes viator) are typically associated with heuweltjies and some investigators have attributed heuweltjie formation to the direct action of termites in redistributing earthen materials. However, rather than being directly responsible in this way, termites simply create nutrient‐rich islands, which support denser vegetation, thereby inducing the localized accretion of aeolian sediments and upward growth of mounds. Contrasting soil features in heuweltjies in one locale indicate these processes have occurred throughout the late Quaternary. Geographic variation in sizes of mounds is explained in part by the local availability of sediments that can be mobilized and redistributed by the wind. Recognition of the operation of aeolian processes in the formation of heuweltjies has important implications for conservation. Any land use that diminishes the sediment‐trapping effect of vegetation on heuweltjies truncates the very process by which new aeolian materials can accrue and may promote irreversible erosion and landscape degradation. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   
7.
降雨条件下堆积层滑坡体滑动机制分析   总被引:6,自引:0,他引:6  
以某物流园区堆积层滑坡体为例,分析了地质结构特征及滑坡类型。在此基础上,运用非饱和土力学方法,分析了滑坡体在降雨条件下的动态稳定性特征,揭示了滑动机制及原因,认为滑坡体位于坡面凹槽处,地形较陡、表面堆积层结构松散、强度差,为滑坡形成提供了便利条件;随着降雨持时的增长,降雨沿堆积体表面的裂缝入渗,在土-岩接触面上汇流贯通,形成滞水,降低了滑面土体的力学性质,产生动态浮托力,同时雨水不断充填裂缝和软弱结构面,产生顺坡向的动态扩张力,使张裂缝扩大,加剧堆积体的变形,促使其发生滑动。  相似文献   
8.
The archaeological site of the Sanxingdui may date back as far as 5,000 years ago. The typical profiles of Palaeo-Stagnic-Anthrosols near the ancient site were selected, which aimed to identify diagnostic horizons employing methodology of soil taxonomic classification and to reveal the micromorphological properties of the paleosols. Under long-term anthropogenic mellowing, the discernible differentiation between anthrostagnic epipedon and its subhorizons as well as hydragric horizon and its subhorizons occurred in Paleo-Stagnie-Anthrosols at the archaeological site of the Sanxingdui. The mieromorphological properties diversified among each specific diagnostic subhorizon, e.g., the developed microstructure in cultivated subhorizon within anthrostagnic epipedon, closely arranged particles and considerable micropores beneficial to both of water conservation and filtration in plow subhorizon within anthrostagnic epipedon, and automorphic optical-orientation clays and calcareous corrosion in hydragric horizons. The findings above of micromorphological features related with diagnostic horizons are significant for soil taxonomic classification.  相似文献   
9.
Micromorphology of solonetz species with special attention to natric horizon was studied in microcatenas at the Dzhanybek Research Station (northwestern Caspian Lowland). The solonetzic (natric) horizon is easily identified, and it occurs at varying depths, which are the criteria for subdividing solonetzes into 4 species, namely, crusty, shallow, medium and deep. In this sequence, the depth of humus-accumulative horizons increases, and the upper boundary of salinity manifestations goes down. The following micromorphological features are assumed as typical for natric horizons: angular blocky microstructures with partially accommodated aggregates having sharp boundaries and narrow plane-like packing voids; b-fabric speckled in the aggregates' centers and monostriated at their peripheries merging into stress coatings; very few interpedal voids; organo-clay coatings; humus- enriched infillings; no calcite and gypsum pedofeatures. A complete set of "natric" features was found only in the crusty solonetz; the shallow solonetz lacks only illuviation coatings, while the medium and deep species have several modifications of fabric elements: blocky aggregates have a rounded shape and are penetrated by biogenic channels favoring their further biogenic reworking; plant residues became more abundant and diverse, and blackened tissues occur; illuviation clay coatings evolved into papules; stress coatings gave birth to striated bfabrics, thus maintaining a high plasma orientation. The thin sections of natric horizons made 50 and 20 years ago were examined to study the influence of environmental changes (increase in precipitation and rise of ground water table) on micropedofeatures. The following processes took place: (i) in the topsoil: humus accumulation and biogenic structurization; (ii) in the natric horizon - re-arrangement of clay coatings into micromass b-fabrics; and (iii) in the lower part of the natric horizon - development of pseudosand fabric, calcite and gypsum formation. The trends revealed are in good agreement with the environmental events.  相似文献   
10.
上海城市天际线与高层建筑发展之关系分析   总被引:4,自引:1,他引:3  
以上海市2000年中心城区航空影像为基础,基于GIS技术分析城市高层建筑与天际线的分布特点及其影响机制。认为城市天际线与高层建筑相互制约,高层建筑的发展与布局必须考虑城市天际线的特色。  相似文献   
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