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801.
The amplitude and rhythm of temperature changes at inter-decadal and inter-centennial timescale were studied, based on the winter-half year temperature change series reconstructed from historical phenological events in eastern China for the past 2000 years, together with the temperature change simulation from ECHO-G model for the past 1000 years, and the quasi-periods of temperature fluctuation were discussed by using wavelet analysis. The results indicate: 1) the maximal amplitude of winter half-year temperature change in eastern China at decadal and centennial scale, was above 2℃ and 0.5-1.0℃ respectively. The reconstructed result indicates that the amplitude of warming during the 20th century was identical with the maximum amplitude before the 20th century in eastern China, but the simulated result suggests that the amplitude of warming has exceeded the maximum amplitude. 2) The rhythms of temperature change at centennial to millennial scale in eastern China were about 100-year, 250-year, 400-year, 600-year and 1000-year. The 20th century, the 1st-3rd century and the 9th-13th century were warm peaks at inter-centennial scale as well as at millennial scale. It is implicated that the warming during the 20th century should be attributed to not only anthropogenic effect, but also natural climate variation. 相似文献
802.
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804.
基于2015、2016年河南省环境监测中心站获取的郑州市9个监测点颗粒物浓度和逐日气象数据,对气象因素和颗粒物浓度相关性进行了研究。结果表明:郑州市大气颗粒物浓度受季节影响较强,总体呈现冬季高、夏季低的趋势。降水量与大气颗粒物浓度呈现明显的负相关。相对湿度的增高不利于PM_(2. 5)浓度的降低,而PM_(10)的浓度则随着相对湿度的增高有所降低。春夏秋三季的主要风向为东北偏东,当春季风为东南风和西风时,颗粒物浓度最低;当夏季风为东北偏东风时,颗粒物浓度最低;秋季吹东北风时,颗粒物浓度最低。冬季吹西北风(郑州冬季盛行风向)时,大气颗粒物质量浓度最低。 相似文献
805.
自动站A文件的格式及预审注意事项 总被引:4,自引:2,他引:4
对报表审核中自动站A文件格式的一些现象进行分析,提出了对A文件的格式进行预审时应注意的几个问题。 相似文献
806.
Simulations of the effects of soil temperature and humidity disturbances on regional climate of China 总被引:1,自引:0,他引:1
Zheng Yiqun Qian Yongfu Yu Ge Gui Qijun Zeng Xinmin Liu Huaqiang 《Meteorology and Atmospheric Physics》2002,81(1-2):85-102
Summary ?This simulation study was applied by a regional climate model (RegCM2) and forced by reasonable soil temperature and humidity
disturbances, in order to examine the disastrous weather and climate-produced such disturbances that were performed in a series
of experiments of different climatic zones, seasons and space/time scales, to recognize the persistence and to understand
the mechanisms of their respective climatic responses under the current climatic background of China.
The simulation results showed that, in regions of East Asian monsoon climate, the soil humidity disturbance (SHD) has greater
impact on posterior climate responses than the temperature disturbance has. The SHD forcing exerts noticeable influence on
rainfall generally. Although the centers of changed precipitation generally do not coincide with those of the disturbances,
the centers are located mostly in downwind areas of the SHD core and in areas of prevailing updraft, even some places far
away; with neighboring dry/moist SHD zones, a bigger rainfall increase tends to show up in the dry region instead of in the
wet one.
The simulation suggested that the SHD lasts for a rather long time, whose length is controlled by the presence of a positive
feedback between the precipitation, the synchronous circulation patterns, the latitude and season, and the intensity of the
SHD forcing.
This study has found that the humidity disturbance (especially from rainfall) is in good correspondence to posterior temperature
that the previous SHD enhancement leads to the subsequent temperature drop in the surface and near-surface layer, while the
centers of lowered temperature can remain more than three months.
Received April 3, 2001; Revised December 19, 2001 相似文献
807.
808.
7月中低纬地区流场的模拟特征 总被引:1,自引:0,他引:1
利用p-σ混合坐标系原始方程5层球带模式,对7月中低纬流进行数值模拟,重点分析近地面流场,经圈环流、纬向风随高度的变化及越赤道气流的模拟特征,结果表明,季风区和非季风区的经圈环流及纬向风的垂直分布,存在着明显的差异,并能清楚地看到海陆热力差异对大气环流的影响。 相似文献
809.
810.
40-30kaBP青藏高原及邻区高温大降水事件的特征、影响及原因探讨 总被引:51,自引:0,他引:51
40-30kaBP相当于末次冰期大间冰阶或海洋氧同位素MIS3晚期。青藏高原在岁差周期夏季高太阳辐射作用下,据古里雅冰芯与若干孢粉记录指示温度比现在高2-4℃,高原及邻区众多大湖的高湖面记录指示大范围降水丰沛。应用Kutzbach水能平衡方程推算了封闭湖泊流域(青海湖、扎布耶/拉果错、阿克塞钦/甜水海)年平均降水可达640mm,560mm,260mm,分别是现代降水的1.7倍,3倍,5倍。高原及邻区包括祁连山以北和云南部分区域在内的大降水对水系河流产生了重大影响。高原内部河湖串联,水系合并;如色林错、班戈错、纳木错串联为高原上最大的内陆水系;若尔盖古湖外流并入黄河水系;长江上游大水在三峡束狭形成强烈旋涡掏蚀成低于海平面的深槽,形成了深槽中、底部的砂砾沉积。这次高温大降水事件是由高太阳辐射导致的由青藏高原高温热低压加强、热带洋面增暖蒸发强烈、南半球越赤道气流增强共同作用而形成的高原特强夏季风,同时极地冰盖迫使西风带南移也可能加强了对高原尤其是西部的降水.H3事件(27kaBP)促进了高温大降水事件的结束,H4事件(35.5kaBP)则可能短期萎缩了夏季风,使高温大降水事件呈现不稳定性特点。 相似文献