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61.
广西湿地资源丰富,但随着经济的快速发展,广西湿地生态系统受到严重的威胁。通过总结广西湿地的实际情况,结合国内的湿地立法进展,分析广西湿地保护的法律现状及存在的问题,提出了广西湿地保护立法的架构和一些建议,为广西湿地立法提供借鉴,以更好地保护广西湿地生态系统。  相似文献   
62.
In the last decade, there has been increasing interest in climate change, pasture degradation and its driving forces, and innovations in nomadic pastoralism on the Tibetan Plateau. However, little is known of indigenous strategies of adaptation to pasture degradation, which limits the effectiveness of adaptation strategies planned by local government. This paper analyzes nomads’ strategies of adaptation to pasture degradation on the basis of a field survey of three townships of Dalag County in the source regions of the Yangtze and Yellow rivers. Pastures there have evidently degraded, with pastures in Wasai mainly in a state of slight or medium degradation and those in Manzhang and Jianshe in a state of medium or severe degradation. With the degradation of pasture, the grazing time is reduced, which affects the livelihoods of nomads. Although the Four-Package Project has commenced in this region, there is still severe fodder shortage in winter and spring. The traditional hay storage strategy does not work because of pasture degradation, and few nomads establish fenced and artificial pastures. Therefore, nomads have employed other strategies, such as renting pasture, providing supplementary feed, and diversifying their livelihoods. Local strategies taken by nomads can provide valuable insights into ecological restoration and livelihood improvement in the region and suggest changes to means promoted by local government. It is necessary to seek new means that combine the best aspects of nomadic pastoralism with modern stockbreeding technologies to help nomads adapt to pasture degeneration and improve their livelihoods.  相似文献   
63.
湿地生态系统服务功能价值评估能够将湿地各项服务功能价值货币化,提供直观的经济数字,是应用较为广泛的一种评估方式。其技术仍处在探索阶段,尚不完善,在应用中反映出许多问题。分析了湿地净化污染、调节大气、调蓄洪水、物质生产等几项代表性的服务功能,总结了评估应用中存在的一些问题,并提出相应的改进建议,为今后的工作提供参考。  相似文献   
64.
以大庆市区湿地为研究对象,利用大庆地区2004年LANDSAT TM遥感图形解译数据和实地调查数据,采用地理信息系统技术(GIS),分析了大庆湿地的类型及分布特征;并选用替代法对大庆湿地进行污染物降解功能价值估算。研究表明,降解污染物功能主要是自然湿地所具有的功能,其次是人工湿地中的稻田湿地,经估算自然湿地降解污染物价值为17.90亿元,人工湿地降解污染物价值为0.017亿元,大庆湿地降解污染物价值17.92亿元。  相似文献   
65.
探讨了北京市海淀区翠湖国家城市湿地公园的水域生物多样性及保护方法,论证了生物防治藻类、高等植被恢复等基于物质循环再生原理的方法对水域生物多样性恢复的效果。实践表明,人工湿地污水净水系统、以营养环节来控制水体富营养化的生物水体防治方法,对翠湖湿地的水质有明显的净化、保护和提升作用,对水域生物多样性的保护起到了积极的作用。  相似文献   
66.
This paper presents the first attempt to use environmental magnetism to quantify sediment provenance on a managed realignment (MR) site. MR is one technique for creating/restoring intertidal habitats and improving the standard of coastal flood protection. Monitoring of MR sites is essential for determining how successful they are at achieving these aims, and normally includes measurement of sedimentation rates through the use of accretion plates and sediment erosion tables (SETs). One limitation of this technique is that the provenance of sediment accreting on realigned surfaces cannot readily be quantified. Our results demonstrate that magnetics-based fingerprinting can successfully apportion sediment source contributions to created/restored coastal saltmarshes with an efficiency similar to that of existing un-mixing models applied to other habitats (82.87%). Analysis of mineral magnetic properties (χFD, IRMsoft and SIRM) demonstrated that the majority of sediment accreting on the Freiston Shore MR Site (Lincolnshire, UK) is derived from established saltmarshes seaward of the breached embankment. This indicates that the MR site may be growing at the expense of neighbouring saltmarshes—thereby undermining the habitat-creation objectives used to justify MR. It is recommended that future MR monitoring programmes consider the provenance of post-breach deposits to help identify any adverse impacts that wetland creation/restoration may have on existing habitats. Further testing of environmental magnetism in coastal saltmarshes and MR sites is necessary to validate wider use of the technique.  相似文献   
67.
Supported by MSS images in the mid and late 1970s, TM images in the early 1990s and TM/ETM images in 2004, grassland degradation in the “Three-River Headwaters” region (TRH region) was interpreted through analysis on RS images in two time series, then the spatial and temporal characteristics of grassland degradation in the TRH region were ana-lyzed since the 1970s. The results showed that grassland degradation in the TRH region was a continuous change process which had large affected area and long time scale, and rapidly strengthen phenomenon did not exist in the 1990s as a whole. Grassland degradation pattern in the TRH region took shape initially in the mid and late 1970s. Since the 1970s, this deg-radation process has taken place continuously, obviously characterizing different rules in different regions. In humid and semi-humid meadow region, grassland firstly fragmentized, then vegetation coverage decreased continuously, and finally “black-soil-patch” degraded grassland was formed. But in semi-arid and arid steppe region, the vegetation coverage de-creased continuously, and finally desertification was formed. Because grassland degradation had obviously regional differences in the TRH region, it could be regionalized into 7 zones, and each zone had different characteristics in type, grade, scale and time process of grass-land degradation.  相似文献   
68.
自然保护区是我国社会经济可持续发展赖以实现的重要自然基础,林业系统占了我国自然保护区的绝大多数。本文对林业系统内湿地类型的自然保护区的类别、级别、区域和面积进行了统计和分析,并根据存在的问题提出了针对性的解决对策。  相似文献   
69.
以浙江省80个重要湿地为研究对象,综合考虑景观、生物多样性及社会发展等多种因素,构建湿地生态状况评价指标体系。采用层次分析法(AHP)和德尔菲法,对13个评价指标进行分级和赋值,计算每处重要湿地生态状况的综合得分,定量表征湿地的生态状况。结果表明:浙江省生态状况评级为“好”的湿地有20个,评级为“中”的湿地有36个,评级为“差”的湿地有24个,分别占浙江省重要湿地总数的25%、45%和30%。浙江省重要湿地生态状况总体良好,但部分湿地存在水质污染、富营养化和外来物种入侵等问题。  相似文献   
70.
基于生态经济学中的外部性原理,结合湿地生态系统的准公共物品属性、外部经济性、外部不经济性以及代际外部性等属性,分析湿地退化的成因.结果表明:湿地萎缩加剧、生态服务功能衰退主要是由于人类缺乏对湿地功能与效益的正确认识,以及不合理的利益分配机制导致的成本外溢现象,从事湿地保护的正外部性行为未得到应有的补偿,负外部性行为未付出应有的代价,并提出应建立因地制宜的多元化生态补偿机制.  相似文献   
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