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991.
The floodplain wetlands of Ganga‐Ichamati interfluves in India have become severely degraded due to incessant, unsustainable utilization practices and lack of community awareness. In spite of the wetlands being the prime source of livelihood for millions, no comprehensive management strategy to accommodate the diverse aspirations and priorities of different users has been implemented for the wetlands to date. In this paper, the authors applied a framework of criteria and indicators to evaluate the status of sustainability achieved by community endeavours in one such wetland. The priorities, consumption patterns and contributions towards wetland conservation of major user groups functioning in that area were assessed by the framework developed through participatory multi‐criteria decision analysis. Results show the deteriorating status of the wetland at present regarding biodiversity conservation and livelihood generation. Fishing activities were identified as the dominant utilization option here followed by agriculture. The paper further explored the preferred alternative utilization strategies for achieving sustainability. Effectiveness of the developed framework in evaluating the extent of sustainability achieved in community endeavours was also highlighted in this context.  相似文献   
992.
About 52% of the world's population now lives in urban areas, and 41% of urban land in developed countries is used for residential areas. The amount and quality of residential green space, an important element in urban residential infrastructure, is closely correlated to city dwellers' quality of life. The quality of green spaces is not only closely correlated to the ecosystem services they provide, but also to their disservices. In order to (i) examine how plant diversity and plant traits vary in different residential areas, (ii) determine the main socio-economic factors driving plant trait variations across different residential areas, and (iii) provide an overview on selected ecosystem services and disservices related to plant diversity, we investigated the flora and socio-economic properties of 83 residential areas in Beijing, China. We found a total of 369 plant species belonging to 99 families and 150 genera. With respect to plant traits, there were 90 annual species, 174 alien species, 169 pollen allergenic species, and 133 species with edible or pharmaceutical value. The number of perennial, alien, ornamental and edible plant species was largest in residential areas completed in the 1990s. The number of allergenic species was highest in residential areas completed prior to 1980. The Simpson, Shannon and Pielou indices for trees and shrubs were highest in areas completed in the 1990s, while those same indices for herbs were highest in residential areas completed prior to 1980. General Linear Model analyses revealed that richness increased with increasing housing price across all groups of species. Principal Component Analysis indicated that housing price and floor-area ratio are the variables that positively correlate with species richness for all groups of species.  相似文献   
993.
怀柔应急水源地作为北京最大的应急地下水源地,在连续10多年的干旱期间,为保障城市供水安全做出了巨大贡献。文章在总结怀柔应急水源地10年供水历程的基础上,评价了连续干旱和应急开采条件下区域水资源的变化;结合南水北调进京的契机,从"资源人工回补"和供水系统"热备运行"两方面开展当地地下水资源涵养研究工作,以保障怀柔应急水源地可持续"应急供水"能力,为应对南水北调供水过程中的突发事件,做好水资源战备储备。  相似文献   
994.
做好文物测绘工作是我国开展大遗址文化遗产保护的前提。随着现代测绘技术的发展,各类先进测绘技术在文物测绘领域中得到了充分的应用,满足了大遗址保护工作的考古修缮、环境整治、规划编制、效果展示等多种不同需求。本文主要介绍了各种现代测绘技术在元上都城大遗址测绘中的应用情况。  相似文献   
995.
Lorraine Moore 《Geoforum》2011,42(1):51-60
This paper uses a case study that explores the impacts of the ivory trade ban on elephant management in Namibia to illuminate the processes and complexities associated with the commodification and neoliberalisation of nature. The paper demonstrates that the ivory trade ban neither prevents the commodification of elephants, nor hampers the neoliberalisation of nature. By tracing Namibia’s experience associated with applying market based approaches to elephant conservation, this paper highlights that the ivory trade ban is only one obstacle among many which prevent the commodification of the ‘living’ elephant. Analysing Namibia’s experiences alongside the wider debates informing elephant conservation reveals that actors of preservation and sustainable utilisation produce elephants. In particular, during the events leading up to the 1989 ivory trade ban, advocates of preservation produced a very lucrative representation of the elephant that relies on market mechanisms. This image has become a powerful commodity that competes with parts of the biophysical elephant (particularly its ivory) and therefore creates new and contesting ways in which elephants can be commodified.  相似文献   
996.
基于水资源可持续利用理念,从水资源承载能力演化周期性、经济社会需用水规模难变性和未来水资源供需关系入手,介绍近60年以来华北平原水资源情势,特别是该平原水资源量、实际用水量和地下水开采量变化特征,并结合未来10到30年区域经济社会发展需用水量趋势,识别和诊断华北平原水资源紧缺因源。结果表明:由于降水量减少导致华北平原缺水(自然资源性缺水)占该平原总缺水量的15.1%~16.4%;因管理缺陷导致水资源浪费的缺水(管理性缺水)占22.1%~24.2%;人口数量和经济社会发展规模过大导致用水量超过区域水资源承载力的缺水(政策性缺水)占59.3%~62.5%。自然资源性、管理性以及政策性缺水的解决对策不同:自然资源性缺水是不依人的意志为转移的,惟有从外域适量调水才能解决;管理性缺水可通过社会文明进步和科技进步不断修正;政策性缺水宜因势利导进行经济社会布局和产业结构调整,特别是限制高耗低效用水产业。即使南水北调工程70.3×108m3/a水进入华北平原,该平原地下水超采情势也难以得到根本性扭转。有新增水源调入或华北平原严控生活和工业用水量,同时大幅压减农业用水量,因势利导优化和逐步调整经济社会布局和产业结构,特别是灌溉农业进行规模化减蒸、降耗、节水的改造,将是缓解华北平原地下水超采和水资源紧缺的根本所在。  相似文献   
997.
Inter-simple sequence repeat (ISSR) markers were used to determine the genetic variation and genetic differentiation of cultured and wild populations of Trachidermus fasciatus, an endangered catadromous fish species in China. Six selected primers were used to amplify DNA samples from 85 individuals, and 353 loci were detected. Relatively low genetic diversity was detected in the cultured population (the percentage of polymorphic loci PPL = 73.80%, Nei’s gene diversity h = 0.178 2, Shannon information index ...  相似文献   
998.
The installation of urban and commercial infrastructures on the coast has a severe impact on the marine environment. This impact is mostly negative but, simultaneously, some of the species that colonize artificial substrata (sometimes rare or threatened) find refuge in man‐made structures. The protection of endangered species is usually provided by marine protected areas or by laws that punish their damage or collection, but effective enclosure and custody must be achieved in the case of easily accessible intertidal species. We used the ferruginous limpet, Patella ferruginea, as a case study because it is the most endangered invertebrate in the Mediterranean. This species, which lives in the intertidal zone and is very accessible to people, is a free‐spawning, protandric hermaphrodite, highly dependent on population density and individual size for its reproductive success. Previous work by the authors found the species is especially abundant on artificial substrates on both shores of the Strait of Gibraltar, where people collect fewer of them. Spanish laws of coastal management do not allow the enclosure of the natural coastline, but artificial installations like harbour breakwaters may be closed or guarded, and visits for educational purposes may be carried out under control. The possibility of declaring some kind of environmental protection for these artificial areas would be a very helpful tool for conservation and management purposes. Protected individuals would grow larger and eventually produce exponentially more offspring, which could be transported by currents to adjacent habitats. Here we propose a protection concept for artificial sites termed Artificial Marine Micro‐Reserve (AMMR), where some endangered species experience a refuge from human disturbance. This concept is a modification of the land micro‐reserves that have been recently declared in small natural sites that keep rare plant species. A network of AMMRs would be the final objective, allowing the creation of a great metapopulation of P. ferruginea and also giving refuge to other endangered species that have been found to grow in this type of substratum. Critically, the declaration of a micro‐reserve cannot be used as a reason in favour of new construction because of the negative influence of such structures on the marine environment, together with the fact that there is no certainty that valuable species will settle on them.  相似文献   
999.
The marine sciences have undergone a sequence of historical changes related to new methodologies, approaches and challenges. Most recently, deteriorating natural ecosystems and threatened component species have prompted a renewed change in the focus of scientific research on the marine environment. This study analyzes the scientific literature on cetaceans during the period 2005–2008 to demonstrate that a key focus of modern research is on conservation-related topics, and then compares it to the period 1970–1973 to demonstrate that this new focus represents a shift from basic biological and ecological issues. On average, approximately 46% of papers published on whales, dolphins and porpoises in 2005–2008 were categorized as conservation oriented versus focused on biology or ecology. This contrasts to approximately 10% in 1970–1973. This shift parallels other marine research subjects, such as benthic communities, coral reefs and sea turtles and reflects a general paradigm shift in marine research towards anthropogenic impacts. This is important guidance for institutions and organizations that wish to base their agendas and decisions on state-of-the-art scientific priorities.  相似文献   
1000.
Sharks play a critical role in the ocean environment yet many species are under threat. Over the last ten years, the international community has taken significant steps to protect shark species and address the threats to them through the adoption and implementation of international laws, plans and programmes. Nevertheless, despite the attention given to this issue, many shark species continue to deteriorate in numbers. While the reasons for this decline are complex and varied, regulatory fragmentation is one contributing factor. Legal regulation is a critical element in achieving effective conservation and management of sharks. This article considers the international laws, plans and programmes that seek to conserve shark species, explores the current fragmented regime and outlines possible strategies to overcome this challenge and enhance shark protection in the future.  相似文献   
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