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941.
This paper presents a case study of the Abanico Medicinal Plant and Organic Agriculture Microenterprise Project in the Arenal Conservation Area, Costa Rica. Microenterprise is the Sustainable Development and the Women in Development model for gender equity and environment of the World Bank, International Monetary Fund and large non-government organizations, like the World Wildlife Fund-Canada. The authors of this paper argue that debt-for-nature investment in microenterprise and ecological economic models are not distinct from neoclassical economic and development models that created the environmental, social and cultural crises in the first place. This case study shows that the world market accommodates only one model of development: unsustainable export-oriented production based on flexible labour markets, low wages, indebtedness and low cost production. Working standards in those micro-enterprises are eroded due to many factors,including indebtedness. What happened at a national level in non-industrial countries with the international debt crisis is now mirrored in individual indebtedness through microenterprise. Is current development policy creating a new form of indentured servitude? Medicinal plants, prior to commodification, were a source of women's power and upon commodification in international development projects, are the source of their exploitation.  相似文献   
942.
为了了解美国海军在这一领域取得的研究进展,回顾了近十年来,美国海军在电磁脉冲生存能力试验与鉴定方面所开展的工作,重点介绍和分析了美国海岸警卫队退役快艇"MONHEGAN"号电磁脉冲试验情况、美军标MIL-STD-4023中关于水面舰船电磁脉冲防护及试验要求、美国海军全舰船威胁级电磁脉冲模拟器参数信息及有关舰船电磁脉冲评估的其他试验基础设施资源需求。  相似文献   
943.
This study aims to develop an integrated model - NFPA-68-BRANN model, which can be used to calculate the vent areas of cubic enclosures with obstacles. Seven experiments regarding vented explosion inside the obstructed enclosure are reviewed and applied to check the accuracy of two existing standards, i.e. the NFPA-68 2018 and the BS EN 14994:2007. Accordingly, the parameters to describe the flame development in the NFPA-68 2018 are amended by adopting the Bauwens model. Bayesian Regularization Artificial Neuron Network (BRANN) model presenting the non-linear relationship between the turbulent flame enhancement factor X and its affecting factors is subsequently developed. Eventually, the NFPA-68-BRANN model is generated by incorporating the BRANN model into the modified NFAP-68 2018. The accuracy of the NFPA-68-BRANN model is validated by using a series of the New Baker Test data.  相似文献   
944.
Recent Changes of Sediment Yield in the Upper Yangtze, China   总被引:2,自引:0,他引:2  
/ Reservoir sedimentation is one of the many environmental problems associated with the Three Gorges Project in China. The rate and characteristics of sedimentation that directly affect the operating life of the reservoir are closely related to soil erosion and sediment transport dynamics in the upstream catchment and to the ability to manage the throughput of sediment-laden waters. The recent changes in sediment yield were examined using gauging data from 187 stations of varying sizes from less than 100 km2 to larger than 1,000,000 km2 in the Upper Yangtze basin between 1956 and 1987. Whereas many previous studies have concentrated on the trends in the main channel of the Yangtze, the distributed pattern of changes across the whole catchment is complex. Results from time series analysis indicate ten stations, mainly located in the Dadu and Wu tributaries (with a total incremental catchment area of 78,963 km2) have shown increasing trajectories of sediment yield, and six stations, located in the upper Jialing and Tuo tributaries (with a total incremental area of 27,816 km2) have experienced decreasing trajectories. By dividing the time series into three components, it is possible to map significant decadal changes in sediment yields that can be related to phases of deforestation and the construction of water conservancy projects. Most of the observed decreases in sediment yield are associated with large reservoir schemes on tributary rivers. The lack of evidence for increasing sediment input to the Three Gorges area masks a considerable variation in sediment conveyance and storage within the Upper Yangtze catchment.KEY WORDS: Sediment yield; Reservoir sedimentation; Three Gorges Project; Time series analysis; China  相似文献   
945.
Different zeolites supported Pt catalysts with micro-mesoporous structure were prepared by organic base tetrapropylammonium hydroxide (TPAOH) treatment and their catalytic oxidation activity for various volatile organic compounds (VOCs) were evaluated. The results reveal that the synergistic effect between Pt nanoparticles and surface acid sites plays an important role in VOCs low-temperature removal. The small size and high dispersion of Pt nanoparticles on the surface of the zeolites would promote the catalytic oxidation of aromatics and alkanes over the Pt/zeolite catalysts, while strong acidity and abundant acid sites of catalysts are in favour of the oxidation of the VOCs containing N and O heteroatoms. In addition, it was found that Pt/ZSM-5 catalyst exhibits the highest oxidation activity for various VOCs low-temperature removal amongst all the catalysts due to the balance of both Pt dispersion and abundant acid sites in the catalyst. This comprehensive consideration should be very helpful when designing and preparing novel catalysts for the low-temperature removal of VOCs.  相似文献   
946.
/ With over 2500 Australian Landcare groups, 65,000 volunteer members, and considerable evidence of program impact, Landcare is an important example of state-sponsored rural development in a developed nation. The agency-community partnership is a fundamental element of Landcare and getting the partnership right is vital to long-term program success. After reviewing the emergence of Landcare in the state of Victoria, the author reports research from a 1995 survey of Victorian Landcare groups. Survey information highlighted the extent of agency-group contact, the important roles agency staff played in many Landcare groups, and the positive impact of agency contact and government funding upon group activity. Large majorities of groups reported they were satisfied with their relationship with agency staff. However, a majority of groups reported money or materials provided to manage land and water degradation was inadequate. Recently proposed changes to the Landcare program will provide government funding of work on private property and may address this concern. A majority of groups also reported support for leadership and management training was inadequate and respondents emphasized the need to revise program guidelines that limit funding for group coordinators. This information highlighted the importance of articulating a practical model of community participation in Australia and adopting a systematic approach to providing agency support for Landcare groups. Reflecting upon the Landcare experience, the author suggests some of the key elements of a practical model of state-sponsored citizen resource management contributing to rural development.KEY WORDS: Landcare; Australia; Community participation; Rural development; Citizen resource management; Sustainable agriculture  相似文献   
947.
The aim of this paper is to check the hypothesis for the environmental Kuznets curve for sulfur dioxide. This involved analysis of: 1. the theoretical basis of the model; 2. the technical problem of SO2 generation; 3 the kind of information used in the estimations; 4. changes in the structure of electric energy production; 5. improvements in energy efficiency; and 6. the recent introduction of cleaning mechanisms in a favourable political context. The conclusion is that, if it is possible to prove the existence of environmental Kuznets curve models, their utility as instruments of economic policy is debatable.  相似文献   
948.
上海市截流外排工程污水扩散影响数值研究   总被引:2,自引:0,他引:2  
城市污水截流外排工程是上海市城市水环境整治的重大战略。文章以CODCr为例,数值模拟研究了上海近岸水域东、南、西三大截流外排干线不同排污方案下污染物的输移扩散规律。结果表明,长江口的水动力条件有利于污水的稀释扩散;在现状排污条件下,无论洪枯季,引起的环境水体污染物CODCr浓度增量均不大,能够满足长江口水环境容量的要求;对于规划排放量的污水,预处理和一级处理条件下引起的环境水体污染物CODCr,浓度增量较为显著,对周围敏感目标的影响也比较大;二级处理条件下所引起的污染浓度增量比较小,对水环境的影响相对较小。因此,在规划城市污水外排工程时,建议必须近期和远期相结合,合理充分利用水体自净能力。  相似文献   
949.
950.
Measurements of xylem water potential, leaf conductance, and leaf pressure–volume characteristics on the geothermal endemic Dichanthelium lanuginosum var. thermale (DILA) were used to delineate operational ranges during wet and dry years and among several microsites at Little Geysers, Sonoma County, California, USA. Plants seldom experienced water potentials more negative that −1.5 MPa. Other nongeothermal, widespread species experienced the lower water potentials typical of chaparral and woodland plants. DILA was able to effectively utilize geothermal water while the widespread species could not and was able to keep stomata open during most of the year. There was evidence to suggest that DILA had some ability to acclimate with significant shifts in Πo and ψo during the dry 1994 summer, especially in the upland microhabitat. Nevertheless, minimum leaf turgor values in the upland came very close to, or dropped below, the 0.2–0.3 MPa threshold thought necessary to maintain stomatal opening and photosynthesis. DILA thus depends upon the unique water status of fumarole soils in the vicinity of the Little Geysers to persist in an otherwise lethal regional mosaic of climate, soil, and vegetation. The physiological data were used to derive reference ranges for subsequent monitoring of DILA at Little Geysers. Such ranges are required to determine the future impact, if any, of geothermal development on the persistence of this rare grass and its complex ecosystem.  相似文献   
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