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排序方式: 共有1343条查询结果,搜索用时 15 毫秒
841.
针对西气东输工程(甘肃段)管道沿线地质灾害现状,本文重点论述了影响管线施工及运营安全的崩塌(不稳定斜坡)、泥石流、洪水冲蚀、风蚀沙埋、特殊岩土灾害的分布和发育特征,并结合线状工程的特点及各种地质灾害的发育特征和危害程度,提出了防治措施,为管道沿线防灾、减灾及灾害治理提供一定的指导依据。  相似文献   
842.
暴雨诱发滑坡致灾机理与减灾方法研究进展   总被引:6,自引:1,他引:5  
暴雨滑坡是多发性的地质灾害.阐述了暴雨诱发滑坡致灾机理、风险评估与减灾方法研究的重要意义.分别从暴雨诱发滑坡的地质力学机制、暴雨诱发滑坡的机理、暴雨诱发滑坡演化过程的数值模拟方法、暴雨滑坡动态风险评估方法以及暴雨诱发滑坡灾害的减灾方法5个方面,详细综述了国内外研究的主要成果和进展.在此基础上,指出了目前暴雨诱发滑坡灾害研究中存在的主要问题.最后,提出了在暴雨诱发滑坡灾害的研究中应以暴雨作用下的斜坡演化动力学过程为主线,以暴雨诱发滑坡的地质力学机制研究为基础,以暴雨诱发滑坡机理研究为核心,以暴雨诱发滑坡灾害的风险评估为手段,以最大可能地防灾减灾为目标.  相似文献   
843.
Chloride (Cl) in urban waterways largely originates from runoff containing deicing salts. Cl is retained in watersheds after deicing ends, resulting in deleterious effects on aquatic biota. Stormwater management ponds (SWMPs), designed to mitigate ‘flashy’ urban runoff response, are known to impact pollutant transport. However, there is little information on what role SWMPs play in the timing and magnitude of Cl transport over different timescales. This study quantifies the mass of Cl retained in two SWMPs over varying timescales. Both ponds are in an urbanizing watershed in south-central Ontario; one drains a commercial area, the other, a residential area. High frequency measurements of water level and specific conductivity, from which flow and Cl concentration were derived, were taken with sensors at pond inlets and outlets. For one SWMP, data were also collected upstream and downstream of the confluence of the pond outflow and the receiving creek to quantify the in-stream response to Cl-laden pond outflows. The findings suggest that SWMPs likely play a role in watershed-scale Cl retention; one SWMP consistently retained Cl while the other had variable retention and release of Cl. In the receiving creek, Cl concentrations downstream of the pond exceeded the acute toxicity threshold for aquatic organisms twice as often as concentrations upstream of the pond, and Cl pulses corresponded to Cl release events from the pond. The results of this study suggest that SWMPs concentrate spatially distributed salt inputs and modify the timing and magnitude of their release to receiving streams. Stream reaches that receive water inputs from SWMPs may be more vulnerable to Cl toxicity than reaches that do not receive flow via SWMPs. The results of this study will help parameterize the role of SWMPs in watershed-scale Cl transport models and geospatial models of salt vulnerable areas.  相似文献   
844.
Environmental policy is touching on ever more aspects of corporate and individual behavior, and there is much debate over what combinations of top-down (government-imposed) and bottom-up (voluntary private sector) measures to use. In democratic societies, citizens’ preferences over such combinations are crucial because they shape the political mandates based on which policymakers act. We argue that policy designs that involve private-public co-regulation receive more citizen support if they are based on inclusive decision-making, use strong transparency and monitoring mechanisms, and include a trigger for government intervention in case of ineffectiveness. Survey experiments in Switzerland (N = 1941) provide strong support for these arguments. Our research demonstrates that differences in co-regulation design have major implications for public support. Another key finding is that there seems to be a contradiction between inclusiveness and democratic accountability for policy outcomes. The findings are surprisingly consistent across two very different green economy issues we focus on empirically (decarbonization of finance, pesticides). This suggests that our study design offers a useful template for research that explores public opinion on green economy policy designs for other issues and in other countries.  相似文献   
845.
祖秉新  刘健  曹葛  杨美艳 《吉林地质》2012,(3):113-114,143
本文就工业与民用建筑中的岩土工程详勘的验槽工序进行了重点阐述,对重要环节的注意事项进行分析和探讨,并提出易出现的问题和预防措施及处理方法。  相似文献   
846.
震后映卧路沿线泥石流发育分布呈面积广、发生频率高等特点。调查结果公路沿线主要发育泥石流两类57条,其中沟谷型泥石流28处,坡面型泥石流29处,沟谷型泥石流以大型—特大型为主,坡面型泥石流以小型为主;针对该区泥石流的发育特征,提出了生物防治和工程治理相结合的防治措施,对映卧路的防灾减灾工程有积极的意义。  相似文献   
847.
岩质边坡破坏主要由结构切割形成的楔形体失稳造成.通过对无锡滨湖区-露天采矿形成的岩质边坡稳定性的评价,介绍利用极射赤平投影法评价岩质边坡稳定性和提出不稳定岩质边坡防治措施的基本原理和方法.  相似文献   
848.
分析了地基强夯前软土和强夯过程中局部橡皮土的成因,鉴别方法,总结了多种预防措施和治理方法,可为同类工程提供借鉴和参考。  相似文献   
849.
http://www.sciencedirect.com/science/article/pii/S167498711200031X   总被引:1,自引:0,他引:1  
Upper Paleozoic coal measures in the Ordos Basin consist of dark mudstone and coal beds and are important source rocks for gas generation.Gas accumulations include coal-bed methane(CBM), tight gas and conventional gas in different structural areas.CBM accumulations are mainly distributed in the marginal area of the Ordos Basin,and are estimated at 3.5×1012 m3.Tight gas accumulations exist in the middle part of the Yishan Slope area,previously regarded as the basin-centered gas system and now considered as stratigraphic lithologic gas reservoirs.This paper reviews the characteristics of tight gas accumulations:poor physical properties(porosity < 8%,permeability < 0.85×10-3μm2),abnormal pressure and the absence of well-defined gas water contacts.CBM is a self-generation and selfreservoir, while gas derived from coal measures migrates only for a short distance to accumulate in a tight reservoir and is termed near-generation and near-reservoir.Both CBM and tight gas systems require source rocks with a strong gas generation ability that extends together over wide area.However,the producing area of the two systems may be significantly different.  相似文献   
850.
青海玛多7.4级地震发生后,本文作者随科考队开展了典型工程的震害调查。本文报道了黄河乡江旁村和昌马河工区这2个典型调查点的建筑震害情况。调查表明:邻近微观震中的黄河乡建筑震害程度相对较轻,主要表现为部分房屋落瓦,砖混结构少数承重墙及框架结构部分隔墙开裂,土木结构房屋部分严重破坏,部分围墙倒塌;而距微观震中以东85 km的昌马河工区建筑震害则相对较重:无抗震措施的砖木结构房屋全部严重破坏或倒塌,具备合理抗震措施的砖混结构基本完好或轻微破坏,在建轻钢厂房均钢柱倾斜、维护墙明显开裂并且围墙多数倒塌。调查分析表明:造成两地震害差异的主要原因为抗震措施差异以及地表破裂和砂土液化影响:黄河乡多数房屋具备合理抗震措施,昌马河工区多数民居缺少抗震措施;昌马河工区附近发现疑似地表破裂痕迹,而紧邻黄河乡的河岸发现砂土液化迹象。这表明昌马河工区的地震作用中类似近场的高频能量可能较多,而黄河乡地区则因砂土液化使得高频地震动作用有所降低,由此造成两地震害程度与震中距呈现反差关系。  相似文献   
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