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521.
为解决威远-长宁地区泥页岩地层井壁失稳、井眼清洁等问题,通过试验优选出适用于高密度油基钻井液体系使用的乳化剂、有机土和降滤失剂等处理剂;通过正交试验设计确定出一种适用于威远-长宁地区页岩气长短水平井使用的高密度油基钻井液体系。其最终配方比例为:5%主乳化剂+2.0%辅乳化剂+2.0%润湿剂+5%降滤失剂+2%有机土+3%CaO、油水比80∶20(25%CaCl2水溶液)。对其性能进行评价,结果表明该体系可加重密度至2.2 g/cm3,加重后性能稳定,可抗水污染达9%,抗岩屑污染至18%,具有较好的抗污染性能,页岩回收率95.11%,抑制性能好,乳化性能稳定。现场应用表明:高密度油基钻井液满足威204H378井页岩气水平井钻井施工需求,全井性能良好,无井漏,井径规则,测井未见异常,顺利完钻。  相似文献   
522.
Site response to earthquake loading is one of the fundamental problems in geotechnical earthquake engineering. Most site response analyses assume vertically propagating shear waves in a horizontally layered soil–rock system and simply ignore the effect of site response to vertical earthquake motion, although actual ground motions are comprised of both horizontal and vertical components. In several recent earthquakes very strong vertical ground motions have been recorded, raising great concern over the potential effect of vertical motion on engineering structures. Being a step toward addressing this concern, this paper presents a simple and practical procedure for analysis of site response to both horizontal and vertical earthquake motions. The procedure involves the use of the dynamic stiffness matrix method and equivalent-linear approach, and is built in the modern MATLAB environment to take full advantages of the matrix operations in MATLAB. The input motions can be specified at the soil–bedrock interface or at a rock outcropping. A detailed assessment of the procedure is given, which shows that the procedure is able to produce acceptable predictions of both vertical and horizontal site responses.  相似文献   
523.
从不同的方位对天津地区两口地震观测专用井记录到的国外7级、国内6级以上的地震进行分析。两口井所处的地理位置、地质结构、井深及其含水层岩性不同,对同一地震的表现形式也不尽相同。通过对比分析,得到井水位对地震的响应特点及几点认识:观测井孔一般对远场大震记录比较灵敏,而对近震及地方震反映不灵敏;井孔水位仪记录的水位波幅与震级、震中距有关;井孔同震效应的能力和井孔对固体潮的反映能力不一致。  相似文献   
524.
上海市大气颗粒物与能见度的关系   总被引:6,自引:0,他引:6       下载免费PDF全文
大气能见度成为当前区域大气环境研究的重要指标,不同粒径的颗粒物对能见度的影响有着显著的区别。本研究在线连续监测了上海市嘉定区2008年11月—2009年1月不同粒径大气颗粒物质量浓度和粒子数浓度的日变化,同步收集了相同区域空气水平能见度的数据。比较不同粒径大气颗粒物质量浓度与空气水平能见度和颗粒物消光系数的相关性,结果表明:中值粒径为0.4 μm和0.65 μm的大气颗粒物对上海嘉定空气水平能见度的影响最显著;中值粒径为0.17 μm、0.26 μm、0.40 μm和0.65 μm的大气颗粒物对颗粒物的消光系数影响较大。该相关系数的分布趋势与各种组分(SO42-、NO3-、NH4+、OC和EC)的粒径分布十分一致,证明了这五种组分是影响大气颗粒物消光系数的重要原因。  相似文献   
525.
Although research on a field investigation about quantification drawdown of ground water wells has hitherto been conducted with emphasis on Sanaa basin which is 3 200 km2 in area characterized by general hazard in quantity and quality of water,there exist uncertainties about the size of the hazardous annual decline in the level of underground water.So the authors are trying to assess reliable hazard data on the depth of ground-water which were obtained by measuring static water level.The data set are twenty six wells from 9 regions which were selected to represent Sanaa basin and collected during the course of the 20 months groundwater monitoring survey from January 2008 to January 2009.The results show that the average drawdown during 20 months to be 3.22 m with an average 0.16 m per month and 2 m per year.  相似文献   
526.
平桥南区页岩气水平井钻井优化设计   总被引:1,自引:1,他引:0       下载免费PDF全文
在分析平桥产建井位部署特点及区块地质条件的基础上,系统总结了该区块页岩气水平井钻井存在的防漏堵漏工艺、钻井提速技术、水平段施工工艺等方面存在的问题,通过对平台部署、井身结构、井眼轨道、“井工厂”钻井模式、钻头选型、钻井液体系及固井工艺等方面的深入研究和优化,形成了平桥南区块页岩气水平井钻井优化设计方案,以实现平桥南区页岩气产建的高效开发。  相似文献   
527.
王永全  周兢 《探矿工程》2017,44(11):35-41
钻探作为煤矿水害防治工作一种重要的技术手段,得到了广泛的应用。煤矿大口径排水井钻进技术、底板多分支水平井地面定向钻进及注浆加固改造技术、井下定向探(疏)放水钻进技术、注浆封堵突水通道钻探技术和矿井突水灾害快速钻进救援技术等煤矿防治水钻探技术,在煤矿水害防治工作中得到了广泛应用,取得了良好效果。加强防治水钻探配套设备的研发和相关钻探工艺技术研究,将有力促进煤矿水害防治工作的发展。  相似文献   
528.
成层竖向排水井地基固结分析   总被引:3,自引:0,他引:3  
实际工程中竖井地基具有成层性,有时竖井也并未完全打穿软土层。在竖井打设区满足竖井等应变固结理论、下卧层满足一维太沙基固结理论假设的基础上,将现有竖井地基固结理论推广到成层未打穿竖井地基情况。利用边界条件和竖直向连续条件,确定该系统的正交关系,并给出了其固结解答,该解具有广泛的适用性。通过对竖井打设区和下卧层层数的变化,即可获得现有关于简单未打穿竖井地基的固结解答。将该解答编制成应用程序,对一算例进行了分析。结果表明,平均固结度按孔压定义和按变形定义是不相同的,硬表层的存在会加快其下土层的固结。  相似文献   
529.
The measurement of the horizontal component, H, of the geomagnetic field represents an important part of geomagneticians work from 1830 to the end of the 19th century. This measurement remained difficult at the required accuracy of 10?9T (1 nT or 1γ), till the advent of proton and optical pumping magnetometers in geomagnetic observatories, around 1955. The measurement of H consisted in determining the mutual torque between two cylindrical magnets, by measuring either oscillation periods or angular deviations. Poisson was the first, indisputably, to propose the general principle of the measurement, in 1825. But Gauss, some years later (1832), successfully operated his famous oscillation–deviation method, described since then in all the elementary manuals of physics. The computation of the mutual torque depends on the tri-dimensional distribution of the magnetization in each one of the magnets. In the absence of an accurate-enough knowledge of these distributions, Poisson, Gauss, and their successors showed how to make the computations with a minimum number of hypotheses on them. Nevertheless physicists, in particular French ones, worked on the ‘distribution of magnetism’ in magnets; the first of them was Coulomb. We come back to this question through experiments conducted in the magnetic observatory of Chambon-la-Forêt, France. To cite this article: B. Leprêtre, J.-L. Le Mouël, C. R. Geoscience 337 (2005).  相似文献   
530.
 Simplified approaches are often used to model the removal of groundwater contamination. These approaches can yield poor remediation schemes because they incorrectly portray the effects of multiple pumping wells. In this study, a pumping configuration designed by graphically overlaying capture zones having an identical, quasi-elliptical shape was evaluated with a numerical mass transport model. After a 3-year period (within which the hypothetical aquifer was to be remediated) the contaminant mass had been reduced by 77%. Due to stagnation zones which developed between extraction wells, approximately 15 years of pumping was required to remediate the aquifer with the overlay configuration. An alternative design, consisting of an extraction well between two injection wells along the long axis of the plume, removed the contaminant within the 3-year design period. Received: 23 October 1995 · Accepted: 18 June 1996  相似文献   
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