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61.
基于Intergraph GIS的基础空间数据库一体化建设研究 总被引:2,自引:1,他引:2
阐述了基于Intergraph GIS的城市基础空间数据的结构和建库的内容,提出了一体化的建库、质量控制、空间数据动态更新以及基于版本信息的历史数据存储与恢复的方法,介绍了一体化建库实例。 相似文献
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以福州滨江城区台江区为例,探讨历史时期、建国时期和现今时期3个演化阶段“涉水”地名文化景观的变化与城市演进的关系.研究结果表明,从历史时期至今,计有消失地名109个,新增地名78个和保留地名30个,消失比率约为50%;反映商业经济业态、方言特色和居住环境的定名方式也随之消失,取而代之的是类似的“城市化”地名,这亦是滨江地域文化的流失.现今“涉水”地名文化景观分别以保留地名与内河体系为增长“极核”和“扩展轴”,两者的叠加效应致使其重心向东迁移.现今地名加快的更新过程折射出城市演进和扩展速度超过建国时期和历史 相似文献
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This paper presents the failure process of the external waste dump of the South Field Mine, the major open pit mine in Greece. The waste materials of the mine were deposited in three phases, forming an average inclination slope 10% and a total height of 110 m from the ground surface. The failure occurred when the third phase of the deposit was initiated. The high moisture content of the waste materials and their deposition over a spring, choking its flow, had as a result the development of high pore water pressure in clayey and marly materials in the base of the deposit. As a consequence, a large scale slope failure incident occurred. The landslide involved the mobilization of waste material in the order of 40 Mm3, while the material that moved outside the boundaries of the waste dump was in the order of 2.5 Mm3. The stability of the waste dump was investigated using the limit equilibrium analysis and different types of models.Limit equilibrium analyses were performed using different methods and considering the clay layer of small shear resistance that exists in the base of the deposit. They do not indicate activation of failure mechanism, only that there is a combination of high pore water pressure that developed in the deposit because the covering of the spring with the clayey materials of the dump. 相似文献
64.
Assessment of gully erosion rates through interviews and measurements: a case study from northern Ethiopia 总被引:3,自引:0,他引:3
Jan Nyssen Jean Poesen Maude Veyret‐Picot Jan Moeyersons Mitiku Haile Jozef Deckers Joke Dewit Jozef Naudts Kassa Teka Gerard Govers 《地球表面变化过程与地形》2006,31(2):167-185
Gullying has been widespread in the Ethiopian Highlands during the 20th century. It threatens the soil resource, lowers crop yields in intergully areas through enhanced drainage and desiccation, and aggravates flooding and reservoir siltation. Knowing the age and rates of gully development during the last few decades will help explain the reasons for current land degradation. In the absence of historical written or photographic documentation, the AGERTIM method (Assessment of Gully Erosion Rates Through Interviews and Measurements) has been developed. It comprises measurements of contemporary gully volumes, monitoring of gully evolution over several years and semi‐structured interview techniques. Gully erosion rates in the Dogu'a Tembien District, Tigray, Ethiopia, were estimated in three representative case‐study areas. In Dingilet, gullying started around 1965 after gradual environmental changes (removal of vegetation from cropland in the catchment and eucalyptus plantation in the valley bottom); rill‐like incisions grew into a gully, which increased rapidly in the drier period between 1977 and 1990. The estimated evolution of the total gully volume in the other areas show patterns similar to those of the Dingilet gully. Average gully erosion rate over the last 50 years is 6·2 t ha?1 a?1. Since 1995, no new gullies have developed in the study area. Area‐specific short‐term gully erosion rates are now on average 1·1 t ha?1 a?1. The successful application of the AGERTIM method requires an understanding of the geomorphology of the study area and an integration of the researchers with the rural society. It reveals that rapid gully development in the study area is some 50 years old and is mainly caused by human‐induced environmental degradation. Under the present‐day conditions of ‘normal’ rain and catchment‐wide soil and water conservation, gully erosion rates are decreasing. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
65.
Overabundance of white-tailed deer is a pervasive problem across the United States. Deer are blamed for increased risk of auto accidents, tick-borne diseases, and overbrowsing of native species. Lethal management techniques, cited as cost-effective and humane, are commonly employed for herd management. However, the approach frequently sparks outrage among various stakeholders who feel killing of animals is unjustified and prefer nonlethal measures. Wildlife managers then face the challenge of communicating with the public to build policy support for lethal management. The Narrative Policy Framework was used to test the effects of differing narratives on public opinion for lethal deer management. Results indicated narratives were influential in shifting attitudes toward and support for a proposed sharpshooting policy even in some cases where respondents were already familiar with the issue and held a previous opinion. This study also supported the utility of the Narrative Policy Framework for examining human dimensions of wildlife issues. 相似文献
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水资源管理模式评述与展望 总被引:1,自引:5,他引:1
导致我国水资源利用效率低下和水危机产生的根本原因,并不完全在于水资源的短缺及缺少节水技术和污水处理循环利用技术,而在很大程度上归因于缺乏一种能够有效地促进水资源高效配置和节约用水的水资源管理模式。因此,建立一种科学合理和高效的水资源管理模式是我国水资源管理制度改革与创新的关键所在,也是我国建设水资源节约型社会的一项重要任务和战略目标。本文重点对国内外常见的几种主要的水资源管理模式的内涵及其管理手段和功能特征等进行了比较分析和研究,在此基础上,探讨了我国水资源管理模式的创新与发展思路,初步提出:建立以流域为单元的水资源生态系统综合管理模式是我国未来水资源管理制度改革的重要发展方向。 相似文献
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李佩成 《地球科学与环境学报》2001,23(2):1-5
在1994年发表的试论地下水研究面临的历史转变的基础上,面对新世纪创造新辉煌的期盼,论述了新的历史时期地下水开发与经管面临的转变和任务有8项即地下水开发与经管的指导思想要从比较放任,转变到高效利用与永续经营;在三水统观统管联合运用中要把地下水作为珍贵后备资源和抗旱的救命水资源加以利用;要把保护水质不受污染作为地下水管理的重大方面,要对含水层进行脆弱性分区管理;要建立和完善包括水位、水质动态观测在内的水环境综合观测网站,加强对地下水的全面观测;要认真总结前50年的地下水开发利用及管理工作,制定未来30年的地下水事业发展规划;要完善地下水开发利用保护法规;理顺地下水专业人才的培养渠道,认真培养地下水领域的高级专门人才;加强讯息网建设,在不断提高地下水科技水平的同时,重视科普宣传工作。 相似文献