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251.
本文基于气象观测站的逐日气压、风速和降水量确定致灾气旋阈值,结合区域气候模式COSMO-CLM (CCLM)输出,研究中国东南沿海地区2021—2050年RCP2.6、4.5、8.5情景下致灾气旋的时空变化特征。并采用人口-发展-环境分析模型(PDE),预测共享社会经济路径SSP2下东南沿海地区人口发展趋势,揭示了致灾气旋人口暴露度演变。研究表明:(1) RCP2.6情景,东南沿海地区平均每年发生致灾气旋6.3次,风速和降水量较基准期(1986—2005年)分别增加9%和15%,72%区域致灾气旋人口暴露度有所增加。暴露在超基准期最大影响面积和最强风速下的致灾气旋人口分别增加2.1亿和0.1亿。(2) RCP4.5情景,致灾气旋年均发生7次,风速和降水量较基准期分别上升16%和32%,89%地区致灾气旋暴露人口增加。暴露在超基准期最大影响面积和最强风速下的致灾气旋人口分别增加2.6亿和0.5亿。(3) RCP8.5情景,致灾气旋年均发生5.8次,风速和降水量较基准期分别增加32%和50%,65%区域致灾气旋暴露人口度有所增加。暴露在超基准期最大影响面积和最强风速下的致灾气旋人口分别增加5.7亿和1.9亿。(4)相比RCP2.6,RCP8.5情景致灾气旋风速和降水量高出23%和35%,暴露于超基准期最大影响面积和最强风速的致灾气旋人口分别多3.6亿和1.8亿。控制温室气体浓度对降低致灾气旋的不利影响具有重要意义。 相似文献
252.
湖南省中医药研究院附属医院作为中医住院医师规范化培训基地,率先提出加强中医临床能力培养及健全考核方案的设想。在加强中医临床能力培养方面,我基地将中医师承教育贯穿始终;分期规划中医临床学习,避免“西化”;加强中医临床培训,提高学员综合能力;加强人文教育,重视医德医风培养等。在健全考核方案方面,采取日常考核、周考核、月考核、出科考核、师承考核、阶段考核与年度考核相结合的方式,并在考核中加大中医比重。通过几年的不懈努力,我基地培训质量明显提高,改革成效显著。 相似文献
253.
This paper presents an efficient algorithm for generating a spherical multiple-cell(SMC) grid. The algorithm adopts a recursive loop structure and provides two refinement methods:(1) an arbitrary area refinement method and(2) a nearshore refinement method. Numerical experiments are carried out, and the results show that compared with the existing grid generation algorithm, this algorithm is more flexible and operable. 相似文献
254.
The long-term time series analysis of the SST (sea surface temperature) in the Eastern Equatorial Pacific Ocean and the monthly MSL (mean sea level) in the tropical Pacific Ocean is conducted. Their quasiperiodic and low-frequency oscillation features are revealed. The significant periods of low-frequency fluctuations for monthly MSL in the area of 20°N-20° S are between 43. 5 months and 50. 0 months, approximating closely to 47. 6 months which is the significant period of SST in the Eastern Equatorial Pacific Ocean. From the results of space-spectral analysis, the low-frequency fluctations of monthly MSL in the tropical Pacific Ocean appear to have a anticlockwise circularly-propagating pattern, which is, the Eastern Pacific Ocean (off-shore of Mexico) →the area of NEC (North Equatorial Current) →the Western Equatorial Pacific Ocean→the area of NECC (North Equatorial Counter-Current)→the Eastern Equatorial Pacific Ocean. The phases of the pattern correspond to those of El Nino cycle. On the basis 相似文献
255.
256.
大别山北麓变质岩系的时代问题 总被引:3,自引:0,他引:3
一、引言 1958年度,笔者曾至豫、皖交界之大别山北麓做过地质测量。在实际工作中有一些体会,想在此做简单介绍,提供参考。解放前很少有人对本区进行过系统的地质调查工作,因此有关资料都很零星。1924年谭锡畴等人曾在商城、信阳间进行过调查,首次建立了“泰山系”及“五台系”两个地层系统,并将固始以南的煤系地层确定为侏罗纪。从现在资料看来,他误将上古生代浅变质岩系划为五台系,而实际上泰山系应包括广布于商城一 相似文献
257.
258.
海南岛大珠母贝遗传多样性分析 总被引:8,自引:0,他引:8
利用RAPD技术首次对中国海南岛环岛的大珠母贝(Pinctada maxima Jameson)遗传多性进行分析。从20条10bp引物中选取7条引物用于群体遗传多样性分析,共检测出22个位点,其中11个位点(占50%)显多态性,Shannon多样性值为0.117。用非加权配对算数平均法(UPGMA)聚类分析的结果:12个体间遗传相似系数最大为1.000,最小为0.706,平均遗传相似系数为0.8438。表明海南岛大珠母贝群体间遗传多样性不一,遗传分化较大,因此很有必要对遗传多样性水平较高的种群,划定保护范围加以重点保护,以扩大和恢复大珠母贝的种质资源。 相似文献
259.
Along with the rapid advance in global industrialization, oil spill events caused by offshore operations, trans- portation and accidents are increasing. Compared with ship surveys, monitoring oil spills through remote sensing has real-time, comprehensive, low-cost advantages, which can effectively guide cleaning and evalu- ation, and reduce the marine ecological destruction resulting from oil spills. Therefore, studying the remote sensing mechanism used to monitor marine oil spills is of great significance for ecological environmen- tal protection. This paper describes an experiment and corresponding analysis based on the above-water method, using the East China Sea coastal turbid water. The analysis shows that "upward short-wave" in ultraviolet and blue-purple bands and its displacement, along with the changing thickness, are important characteristics for distinguishing between the oil slick and the sea water, and also to differentiate oil slicks of different thicknesses. From blue to near-infrared bands, the spectrum of lube oil is flatter than that of diesel, and the diesel spectrum rises faster than the lube spectrum on the right side of the trough at 400 nm. These two features form an important basis for differentiating diesel from lube oil. These analyses will further the development of oil spill remote sensing in the East China Sea. 相似文献
260.
In order to study the stability of the Qinghai-Tibet Highway embankment at Chumaerhe in the permafrost region of northwest China, the ground temperature and deformation at different depths were monitored under the left and right shoulders of the embankment where thermosyphons were set up only on the left shoulder. Based on the monitored data, characteristics of ground temperature and deformation of the left and right shoulders are analyzed and discussed. The results show that the start time of freezing or thawing of the seasonal active layer was about one to two months later than that of the embankment body itself. The stability of each shoulder was mainly controlled by the settlement of different soil layers,whereasfrost heave of soil had scarcely any effect on the stability of the embankment. For the left shoulder, the settlement was mainly influenced by the seasonal active layer and then by the embankment body itself,due to freeze-thaw cycles which may change the soil properties; however, the permafrost layer remained fairly stable. For the right shoulder, creep of the warm permafrost layer was the main influence factor on its stability, followed by settlement of embankment body itself, and finally settlement of the seasonal active layer. Compared with the deformation of the left shoulder, the permafrost layer under the right shoulder was less stable, which indicates that the thermosyphons had a significantly positive effect on the stability of warm permafrost. 相似文献