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91.
四川德昌县典型泥石流灾害风险评价 总被引:11,自引:0,他引:11
四川德昌县虎皮弯沟、凉峰沟和凹米罗沟为凉山州安宁河一级支流茨达河的3条支沟,泥石流危险度依次为0.49,0.65和0.45,分别属于中度危险、高度危险和中度危险的泥石流沟;泥孑亍流易损度依次为0.79,0.82和0.81,分别属于高度易损、极高易损和极高易损的泥石流沟;泥石流风险度依次为0.39,0.53和0.37,均属于高风险泥石流沟,容易造成较大的泥石流灾害损失。2004年8月24日,因持续高强度降雨,导致3沟同时暴发泥石流,给当地社会经济和人民群众的生命财产造成丁巨大损失。建立了泥石流灾害损失评价方法,对这3场泥石流灾害损失进行了评价。针对此类严重灾害的高风险泥石流沟,提出了相应的整治建议,以减少和避免重大灾害的再次发生。 相似文献
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93.
深圳地铁施工影响区环境安全与第三方监测 总被引:6,自引:3,他引:6
在讨论如何确保地铁施工影响区环境安全的基础上 ,给出了深圳地铁土建施工第三方监测的概念 ,详细阐述了第三方监测的目的、作用、管理体系、实施内容和工作程序 ,论述了第三方监测与业主、承包商、监理之间的关系。深圳地铁建设的实践表明 ,第三方监测是业主确保地铁施工影响区环境安全的有效管理模式 ,在地铁建设中极有推广价值。 相似文献
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95.
David Fowler Jennifer B. A. Muller Lucy J. Sheppard 《Water, Air, & Soil Pollution: Focus》2004,4(6):3-8
This paper provides the background to this special issue, outlining the extent to which the global atmospheric nitrogen cycle has been modified by human activity and outlining the range of effects. The global total emissions of reduced and oxidized nitrogen, amount to 124 Tg N, and exceed those from natural sources (34 Tg N) by almost a factor of four showing the extent to which anthropogenic activity has taken over the global N cycle. Of the 124 Tg N, 70 Tg N is emitted in the oxidized form, largely as NO and 70% of which results directly from anthropogenic activity. The remaining 54 Tg N is emitted as NH3, (66% anthropogenic). The enhanced nitrogen emissions are associated with a range of local, regional and global issues including, acidification, eutrophication, climate change, human health and tropospheric O3. The paper also places the Global Nitrogen Enrichment (GaNE) research programme in the UK in a wider perspective. 相似文献
96.
火电厂烟气脱硫工程往往是在场地或其他条件受到诸多限制的情况下进行的,设计中总平面布置的作用显得尤其突出。以几个电厂脱硫工程的设计为例,探讨如何充分利用已有务件,协调脱硫与整个厂区总平面布置的关系,以使设计合理,经济。 相似文献
97.
Black liquor gasification–combined cycle (BLGCC) is a new technology that has the potential to increase electricity production of a chemical pulping mill. Increased electricity generation in combination with the potential to use biomass (e.g. bark, hog fuel) more efficiently can result in increased power output compared to the conventional Tomlinson-boiler. Because the BLGCC enables an integrated pulp and paper mill to produce excess power, it can offset electricity produced by power plants. This may lead to reduction of the net-CO2 emissions. The impact of BLGCC to offset CO2 emissions from the pulp and paper industry is studied. We focus on two different plant designs and compare the situation in Sweden and the US. The CO2 emissions are studied as function of the share of recycled fibre used to make the paper. The study shows that under specific conditions the production of “CO2-free paper” is possible. First, energy efficiency in pulp and paper mills needs to be improved to allow the export of sufficient power to offset emissions from fossil fuels used in boilers and other equipment. Secondly, the net-CO2 emission per ton of paper depends strongly on the emission reduction credits for electricity export, and hence on the country or grid to which the paper mill is connected. Thirdly, supplemental use of biomass to replace fossil fuel inputs is important to reduce the overall emissions of the pulp and paper industry. 相似文献
98.
James F. Saunders Marylee Murphy Martyn Clark William M. Lewis 《Journal of the American Water Resources Association》2004,40(5):1339-1349
ABSTRACT: Historical flow records are used to estimate the regulatory low flows that serve a key function in setting discharge permit limits through the National Pollutant Discharge Elimination System, which provides a nationwide mechanism for protecting water quality. Use of historical records creates an implicit connection between water quality protection and climate variability. The longer the record, the more likely the low flow estimate will be based on a broad set of climate conditions, and thus provides adequate water quality protection in the future. Unfortunately, a long record often is not available at a specific location. This analysis examines the connection between climate variability and the variability of biologically based and hydrologically based low flow estimates at 176 sites from the Hydro‐Climatic Data Network, a collection of stream gages identified by the USGS as relatively free of anthropogenic influences. Results show that a record of 10 to 20 years is necessary for satisfactory estimates of regulatory low flows. Although it is possible to estimate a biologically based low flow from a record of less than 10 years, these estimates are highly uncertain and incorporate a bias that undermines water quality protection. 相似文献
99.
Ryan C. Schwartz Peter J. Deadman Daniel J. Scott Linda D. Mortsch 《Journal of the American Water Resources Association》2004,40(3):647-662
ABSTRACT: Recent research that couples climate change scenarios based on general circulation models (GCM) with Great Lakes hydrologic models has indicated that average water levels are projected to decline in the future. This paper outlines a methodology to assess the potential impact of declining water levels on Great Lakes waterfront communities, using the Lake Huron shoreline at Goderich, Ontario, as an example. The methodology utilizes a geographic information system (GIS) to combine topographic and bathymetric datasets. A digital elevation surface is used to model projected shoreline change for 2050 using water level scenarios. An arbitrary scenario, based on a 1 m decline from February 2001 lake levels, is also modeled. By creating a series of shoreline scenarios, a range of impact and cost scenarios are generated for the Goderich Harbor and adjacent marinas. Additional harbor and marina dredging could cost as much as CDN $7.6 million. Lake freighters may experience a 30 percent loss in vessel capacity. The methodology is used to provide initial estimates of the potential impacts of climate change that can be readily updated as more robust climate change scenarios become available and is adaptable for use in other Great Lakes coastal communities. 相似文献
100.
基于可接受安全间距的单车道交通流模拟模型 总被引:1,自引:1,他引:1
交通流微观模拟是采用计算机对交通流进行描述及分析的方法。尤其对于复杂的交通流而言,微观模拟具有明显的优势,然而模拟的准确与否,关键在于模型的建立。笔者即是在研究我国单车道交通流特点的基础上,借鉴车道变换理论,基于驾驶员可接受的交通安全间距,分析安全变换车道的各间距之间的关系,阐述了有超车的单车道交通流模拟模型的建立方法 相似文献