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951.
《International Journal of Digital Earth》2013,6(7):719-736
ABSTRACTRecently the cultivation of opium poppy in Afghanistan reached unprecedented levels. It is agreed that the complex and coupled interactions of social, economic and environmental drivers are crucial for understanding the spatial and temporal dynamics of opium poppy cultivation in Afghanistan. In this context, we present an integrated risk concept, which considers environmental and socio-economic drivers of opium poppy cultivation. A set of spatially explicit indicators for the environmental suitability and socio-economic vulnerability was established and populated from a variety of databases. Subsequently, novel methods of modelling homogeneous and spatially explicit regions of opium poppy cultivation suitability, socio-economic vulnerability and risk are developed and applied. The risk assessment results demonstrate the complex nature of the illicit crops production in Afghanistan and prompt a more profound examination of the drivers of opium poppy cultivation in a spatial context. The study also confirms what has already been widely discussed in literature: that reasons for cultivation are spatially diverse and often distinct, meaning that any formulation of generalized explanations cannot be drawn without ignoring a more complex reality. Thus, an integrative spatial view of risk, which integrates the social dimension as well as environmental parameters, is required to better identify context-specific intervention measures. 相似文献
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An increasing number of low, medium, and high resolution SAR satellites creates a demand for a generalized sensor model to replace the rigorous sensor model (RSM). The rational polynomial coefficient (RPC) model is a generic sensor model which accurately fits the object-image geometry for various sensor systems with different coefficient values. It has been widely used as an alternative to RSM for photogrammetric processing of optical images, but its applications to SAR images are rarely discussed in publications. In this paper, the feasibility and practicability of the RPC model for SAR images are studied. The RPC model can not only be used to replace the RSM (range–Doppler model for SAR), but also applied to the processing chain for SAR data, thus facilitating the processing of SAR and InSAR data for end users. 相似文献
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黄秉维先生是国际著名地理学家,中国现代地理学的重要开拓者,1955年当选为中国科学院首批学部委员(院士),他长期担任原中国科学院地理研究所所长、中国地理学会理事长。2013年2月是黄秉维先生诞辰100周年。为了纪念黄秉维先生对中国现代地理学发展做出的卓越贡献,弘扬他的学术思想和优良学风,服务地理学的创新与发展,3月29日,中国科学院地理科学与资源研究所(简称地理资源所)和中国地理学会联合举办了"黄秉维先生学术思想研讨会"。来自国家自然科学基金委员会等有关部委,中国科学院院士工作局、资源环境科学与技术局、基建局等院内单位,全国有关地理研究院所、高等院校,中国科协系统等40家单位的领导、专家学者,黄秉维先生的亲属、著名科学家的亲属等共计200余人参加了会议。两院院士孙鸿烈、曾庆存、石玉林、刘昌明、李文华、童庆禧、郭应禄、郑度、孙九林、陆大道、秦大河、姚檀栋、陶澍、傅伯杰等先生参加了研讨会,黄秉维先生生前的同事、助手和学生李文彦、王恩涌、邓先瑞、孙惠南、杨桂山、柳林等先生也在会上发言。会前,地理资源所和中国地理学会组织编辑出版了《黄秉维先生诞辰100年纪念文集》,编辑制作了《行所当然而不惑于偶然——纪念黄秉维先生诞辰100周年》纪录片,在《地理学报》、《地理研究》杂志发表了回顾、纪念性文章。除另行发表的若干学术报告外,现根据录音,将部分专家、学者的发言整理发表,以飨读者。 相似文献
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Time series analysis has two goals, modeling random mechanisms and predicting future series using historical data. In the present work, a uni-variate time series autoregressive integrated moving average (ARIMA) model has been developed for (a) simulating and forecasting mean rainfall, obtained using Theissen weights; over the Mahanadi River Basin in India, and (b) simulating and forecasting mean rainfall at 38 rain-gauge stations in district towns across the basin. For the analysis, monthly rainfall data of each district town for the years 1901-2002 (102 years) were used. Theissen weights were obtained over the basin and mean monthly rainfall was estimated. The trend and seasonality observed in ACF and PACF plots of rainfall data were removed using power transformation (α=0.5) and first order seasonal differencing prior to the development of the ARIMA model. Interestingly, the ARIMA model (1,0,0)(0,1,1) 12 developed here was found to be most suitable for simulating and forecasting mean rainfall over the Mahanadi River Basin and for all 38 district town rain-gauge stations, separately. The Akaike Information Criterion (AIC), goodness of fit (Chi-square), R 2 (coefficient of determination), MSE (mean square error) and MAE (mea absolute error) were used to test the validity and applicability of the developed ARIMA model at different stages. This model is considered appropriate to forecast the monthly rainfall for the upcoming 12 years in each district town to assist decision makers and policy makers establish priorities for water demand, storage, distribution, and disaster management. 相似文献
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JERZY CYBERSKI 《水文科学杂志》2013,58(3):317-320
ABSTRACT The abrasion of banks of certain storage reservoirs can have considerable importance. Cases are known where the shift of the bank line forecast to take place within a period of ten or fifteen years was exceeded during the first year of operation of the reservoir. However, transformation and erosion of banks in other reservoirs or other bank sections, although anticipated, either has not occurred, or, when it did, its intensity was much lower than expected. This is why the problem of transformation of the near-shore zone in reservoirs is attracting more and more attention from many scientific institutes. The paper presents the subject, methods and results of research on the transformation and erosion of the reservoir banks. The main effort has been concentrated on trying to establish the relationships between geological-morphological and climatic-hydrological conditions. It has been stated that the dynamic potential of the reservoir is of decisive importance. This potential, depending on the morphometry of the reservoir and the meteorological conditions (mainly wind) exerts an influence on the reservoir shore line. Consequently, the erosive-accumulation processes become interrelated, resulting in transformation of the bank zone and its adaptation to new conditions. 相似文献
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