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761.
利用最邻近指数、核密度、ESDA、网格维数等方法,并基于1978—1985、1986—1997、1998—2016年不同时间阶段,以上海市博物馆为研究对象,探讨其时空演变特征及影响因素。结果发现:1)博物馆可分为探索起步、稳步发展和高速发展3个阶段,内部类型差异显著、多元变化趋势明显;2)博物馆主要分布于中心城区及黄浦江沿岸,空间上不断集聚并呈现典型的“核心—边缘”特征,全局分布具有空间自相关特性、冷热点变动显著;3)中心城区博物馆在分布上表现为分形结构较为复杂的放射状演变趋势,博物馆类型逐渐丰富和多元,不同阶段博物馆类型各有偏重;4)博物馆的时空特征演变是历史文化资源、政府政策导向、区域经济水平、区域人口分异和交通通达条件等多种因素综合作用的结果。 相似文献
762.
Zhuang Yuanhuang Zhang Jingyong Wang Lin 《Theoretical and Applied Climatology》2018,131(3-4):1261-1272
Theoretical and Applied Climatology - In recent times, Ibadan has been experiencing an increase in mean temperature which appears to be linked to anthropogenic global warming. Previous studies have... 相似文献
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为充分发挥多普勒天气雷达网的联网观测优势,依托已有科研成果,开发了多普勒天气雷达三维数字组网软件系统。介绍了该系统的整体设计、系统框架、主要功能模块、数据处理流程和相关算法,分析了系统性能及组网结果的实用性、可靠性,讨论了实际应用中影响组网效果的两个重要因素。业务运行测试及实例分析结果表明:该系统运行稳定;在微机上可实现约15部雷达、频率为6min左右的高时间频率的三维组网;算法合理,组网结果可靠;为中小尺度天气分析提供了便利,为临近天气预报开发等工作提供了数据基础;有必要对软件系统进行升级,以便更好地满足应用需求, 提高组网结果质量。 相似文献
767.
美国小麦产量业务预报方法研究 总被引:1,自引:0,他引:1
利用综合诊断指标,研究了预测年美国小麦生长季逐日平均气温和降水量与历史上任意一年对应气象要素的关系。根据小麦产量历史丰歉气象影响指数,建立了基于地面气象要素的美国小麦产量预报模型;研究分析了西太平洋月平均海温、北半球500hPa平均高度场环流资料与美国小麦产量的关系,利用主要影响因子,分别建立了基于海温、环流资料的美国小麦产量预报模型。根据各预报模型的稳定性,利用加权方法建立了美国小麦产量业务预报集合模型。1995~2004年预报检验和2005~2006年预报试验结果表明:集合模型的预报准确率基本都在92%以上,能够满足业务服务的需要。 相似文献
768.
Prediction of debris-flow danger area by combining hydrological and inundation simulation methods 总被引:1,自引:0,他引:1
Debris flows have caused serious human casualties and economic losses in the regions strongly affected by the Ms8.0 Wenchuan earthquake of 2008. Debris flow mitigation and risk assessment is a key issue for reconstruction.The existing methods of inundation simulation are based on historical disasters and have no power of prediction.The rain-flood method can not yield detailed flow hydrograph and does not meet the need of inundation simulation. In this paper,the process of water flow was studied by using the Arc-SCS model combined with hydraulic method,and then the debris flow runoff process was calculated using the empirical formula combining the result from Arc-SCS.The peak discharge and runoff duration served as input of inundation simulation. Then,the dangerous area is predicted using kinematic wave method and Manning equation.Taking the debris flow in Huashiban gully in Beichuan County,Sichuan Province,China on 24 Sep.2008 as example,the peak discharge of water flow and debris flow were calculated as 35.52 m3·s-1 and 215.66 m3·s-,with error of 4.15%compared to the measured values.The simulated area of debris-flow deposition was 161,500 m2,vs.the measured area of 144,097 m2,in error of 81.75%.The simulated maximum depth was 12.3 m,consistent with the real maximum depth between 10 and 15 m according to the field survey.The minor error is mainly due to the flow impact on buildings and variations in cross-section configuration.The present methodology can be applied to predict debris flow magnitude and evaluate its risk in other watersheds inthe earthquake area. 相似文献
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Investigation on the direct radiative effect of fossil fuel black-carbon aerosol over China 总被引:2,自引:1,他引:1
Bingliang Zhuang Fei Jiang Tijian Wang Shu Li Bin Zhu 《Theoretical and Applied Climatology》2011,104(3-4):301-312
In China, due to lack of countrywide monitoring and coarse emission inventory of black carbon (BC) in early years, there are large uncertainties as to the estimations of its loading, direct radiative forcing (DRF) and climate response. Here, we apply an up-to-date emission inventory of BC in 2006 to investigate its loading, optical depth (AOD) at 550?nm and DRF using the coupled Regional Climate Chemistry Modeling System (RegCCMS). A state of the art air quality model (WRF/Chem) is also used to access surface BC concentration. Simulated surface concentrations of BC from these two models were compared with observations, while the AOD was compared with the results both from the Goddard Chemistry Aerosol Radiation and Transport (GOCART) model and from satellite and ground-based simulations. Results show that RegCCMS presented similar patterns and levels of annual mean-surface BC concentration to those of WRF/Chem. The regional distributions and monthly variations of RegCCMS BC were reproduced well in comparison to observations. Simulated pattern of AODs are consistent to but lower than those from satellite (Omi-0.25°) and AERONET simulations. Annual mean DRFs mainly distribute in the area with high BC loadings, with regional mean of 0.75?W?m?C2 and predicted global mean of 0.343?W?m?C2. In general, the results are about 0.4?C5 times for regional column burden, about 2 times as high for regional mean DRFs, about 1.3?C1.8 times for global mean DRFs and about 3?C4 times for AOD at 550?nm as compared to those in previous studies in China. These increasing DRFs of BC imply that its warming effect and climate response should be stronger and the DRF of total aerosols should be weaker (less negative). 相似文献