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991.
茅台酒用高粱产量品质与气象因子研究   总被引:3,自引:0,他引:3  
为研究仁怀市茅台酒用高粱栽培基地气象要素对高粱产量和品质影响的关键因子和关键时期.采用空间曲面插值方法,对仁怀及周边气象站气象数据进行空间插值,得到100m×100m的高分辨要素空间分布栅格数据.然后应用种植在海拔370~1301m的127个地段高粱数据与气象资料进行分析.结果表明,温度、日照对产量影响主要在齐穗期后10d~40d;降水影响产量的关键时段在齐穗前50d到齐穗后40d.气象因子对产量的影响都十分显著(>99%置信度).降水、日照与单宁含量呈现较显著反相关(>95%置信度),并且都出现在齐穗前20d ~50d左右.但气象因子与蛋白质含量无显著相关.  相似文献   
992.
This study examines the time and regime dependencies of sensitive areas identified by the conditional nonlinear optimal perturbation(CNOP) method for forecasts of two typhoons.Typhoon Meari(2004) was weakly nonlinear and is herein referred to as the linear case,while Typhoon Matsa(2005) was strongly nonlinear and is herein referred to as the nonlinear case.In the linear case,the sensitive areas identified for special forecast times when the initial time was fixed resembled those identified for other forecast times.Targeted observations deployed to improve a special time forecast would thus also benefit forecasts at other times.In the nonlinear case,the similarities among the sensitive areas identified for different forecast times were more limited.The deployment of targeted observations in the nonlinear case would therefore need to be adapted to achieve large improvements for different targeted forecasts.For both cases,the closer the forecast time,the higher the similarities of the sensitive areas.When the forecast time was fixed,the sensitive areas in the linear case diverged continuously from the verification area as the forecast period lengthened,while those in the nonlinear case were always located around the initial cyclones.The deployment of targeted observations to improve a special forecast depends strongly on the time of deployment.An examination of the efficiency gained by reducing initial errors within the identified sensitive areas confirmed these results.In general,the greatest improvement in a special time forecast was obtained by identifying the sensitive areas for the corresponding forecast time period.  相似文献   
993.
The outputs of three GCMs, ECHAM5, CCSM3 and HadCM3, are downscaled for the eastern Mediterranean–Black Sea region for the period 1961–1990 using a regional climate model, RegCM3, to assess the capability of these models in simulating the climatology of the region. In addition, the NCEP/NCAR Reanalysis data are also downscaled for the same period to display the performance of the regional climate model for the same region, which constitutes a relatively complex terrain and rich variety of climates. The gridded observational dataset of CRU is primarily used in the evaluation of the models, however, a regional dataset, which is based on a relatively dense gauging network, is also used to see how it affects the performance measures of the models. The reanalysis simulation indicates that RegCM3 is able to simulate the precipitation and surface temperature as well as the upper level fields reasonably well. However, it tends to overestimate the precipitation over the mountainous areas. All three GCM models are found to be highly skilled in simulating the winter precipitation and temperature in the region. The two models, ECHAM5 and HadCM3, are also good at simulating the summer precipitation and temperature, but the CCSM3 simulation generates dryer and warmer conditions than the observations for the whole region, which are most likely a result of the dryness in the upper levels of the original outputs. The use of the regional observational dataset does not necessarily improve the pattern correlations, but it yields better match between the modeled and observed precipitation in terms of variability and root-mean-square difference. It could be said that the outputs of these GCMs can be used in the climate change downscaling and impact assessment studies for the region, given that their strengths and weaknesses that are displayed in the present study are considered.  相似文献   
994.
利用相似权重集成预报法对辽宁区域12个数值模式预报的降水量进行集成,并投入业务化应用。结果表明:通过对2009年5月1日至10月20日的24 h降水量预报进行TS评分,发现降水集成方法要优于12个集合成员的单个预报,同时也要优于简单的集合平均。试验表明,滞后时间和扩大圈数对集成预报效果影响很大,而单个的集合成员对集成预报效果影响较小。根据试验结果修改集成方法应用方案,按照不同降水量级和预报时效选择扩大的圈数,预报效果好于原方案,对大量级、长时效预报改进更明显,其中25 mm量级预报时效72 h的TS评分增加了20%或以上,具有实际应用价值。  相似文献   
995.
穆松宁  周广庆 《大气科学》2012,36(2):297-315
本文主要利用美国冰雪资料中心 (The National Snow and Ice Data Center) 提供的卫星反演积雪资料和ERA40土壤温度再分析资料, 采用相关分析, 对欧亚北部冬季新增雪盖面积 (冬季TFSE) 与我国夏季气候异常关系的可能物理途径进行了初步研究。结果表明, 春夏季陆面季节演变异常是上述“隔季相关” 的重要纽带: 当冬季TFSE偏大时, 欧亚北部大范围积雪—冻土自西向东、 由南向北的融化进程明显减慢, 受其影响, 至夏季, 东亚中高纬区积雪和地表冻土的融化异常强烈, 土壤温度明显偏低, 这种夏季陆面异常可能通过自身的冷却作用, 通过加强东亚中高纬异常北风对东亚中纬区夏季变冷产生直接影响, 进而与西太平洋副热带高压, 乃至与我国江南夏季降水异常产生关联; 冬季TFSE偏小时相反。分析表明, 冬季TFSE信号在东亚中高纬局地的春季积雪—冻土融化过程中被加强, 并在夏季达到显著。  相似文献   
996.
The Purulia carbonatite of West Bengal, India is a dyke occurring within the 100 km long South Purulia Shear Zone (SPSZ), which marks the boundary between the Singhbhum Group of Rocks and the Chhotanagpur Granite Gneissic Complex (CGGC). It is composed essentially of calcite with apatite, amphibole, phlogopite, biotite, magnetite and ilmenite as common accessories. Based on optical properties and mineral chemistry two varieties of the amphibole are recognized: magnesiokatophorite and richterite. The latter is characterized by a relatively high content of Si and Na, while the former is enriched in Al and Ca. Such a composition of the amphibole is characteristic for the intermediate to the late stage carbonatite development. These two co-existing amphiboles reflect a sudden variation in total pressure within the magma chamber during the intrusion of the carbonatite dyke. It is inferred that the magnesiokatophorite started crystallizing first along with calcite and apatite. Subsequently, the ascent of carbonatitic magma to a more shallow depth (hypabyssal) resulted in the formation of the richterite. The difference in amphibole composition reflects a variation in the total pressure within the magma chamber that took place during the formation of the Purulia carbonatite. However, an alternative explanation, such as wallrock contamination, or liquid immiscibility, followed by carbonate magma segregation or magma mixing, may also be possible. There is, however, no evidence corroborating such an interpretation.  相似文献   
997.
综合物探方法在天津市浅层贝壳堤地质环境调查中的应用   总被引:1,自引:1,他引:0  
 用多种物探方法进行可行性试验,确定了贝壳堤与周围介质的具体物性差异。通过瑞利波勘探与反射波最佳偏移距技术进行探测,将其资料相互对比验证,查明了工区内贝壳堤的赋存状态,推测出贝壳堤的边界、埋深及厚度,为规划港东区新城就如何保护贝壳堤的问题提供翔实资料。  相似文献   
998.
天津境内在宝坻断裂以南的广大平原区,蕴藏着丰富的中低温地热资源。随着开采程度的加强,研究地热流体的补给和迳流条件显得日益重要。利用环境同位素技术确定了天津各热层储地热流体的补给来源和年龄。并结合地热流体的水化学特征,初步分析了各热储层之间的联系程度和迳流关系。  相似文献   
999.
陕西宝鸡地区千阳县塌山黄土滑坡稳定性分析   总被引:2,自引:1,他引:1  
通过对宝鸡塌山黄土滑坡详细调查和钻探结果表明:具有特殊性的黄土为塌山黄土滑坡形成提供了物质基础;斜坡地形地貌、顺向斜坡结构、黄土节理等为塌山黄土滑坡提供了边界条件;人类活动、降水等是塌山黄土滑坡形成的主导诱发因素;多种因素相辅相成,导致塌山黄土滑坡发生发展。其次,采用SARMA法和FLAC法对滑坡稳定性进行了计算和模拟分析,通过对滑坡体土体应力的分析与滑坡安全系数计算表明,在天然状态下塌山黄土滑坡现今整体稳定,局部(滑坡前缘左侧)有失稳可能,这与野外调查塌山黄土滑坡现今变形特征以及整体稳定局部可能失稳的结论基本一致。而在饱和状态、天然状态+地震、饱和状态+地震3种工况下,塌山黄土滑坡整体失稳的可能性较大。  相似文献   
1000.
作为华北陆块北缘的碱性岩体之一,河北矾山钾质碱性超镁铁岩-正长岩杂岩体赋存着中国最大的内生磁铁矿-磷灰石矿床。关于其形成时代,已经发表的K-Ar、Rb-Sr和Sm-Nd法定年结果差别较大,因此需要采用更精确的定年方法限定岩体的形成时代。通过对矾山杂岩体的辉石正长岩样品进行SHRIMP锆石U-Pb定年,得到了218±2Ma的结果。由于定年样品取自构成矾山杂岩体主体、形成最晚的第三岩相带,这个年龄限定矾山杂岩体形成于晚三叠世。现有的锆石U-Pb年代学资料表明,晚三叠世侵入岩在华北陆块北缘、东缘、南缘普遍存在,成为中国东部晚三叠世构造-岩浆活动的显著特征之一。  相似文献   
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