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611.
Sullivan TJ Cosby BJ Webb JR Dennis RL Bulger AJ Deviney FA 《Environmental monitoring and assessment》2008,137(1-3):85-99
A modeling study was conducted to evaluate the acid-base chemistry of streams within Shenandoah National Park, Virginia and
to project future responses to sulfur (S) and nitrogen (N) atmospheric emissions controls. Many of the major stream systems
in the park have acid neutralizing capacity (ANC) less than 20 μeq/L, levels at which chronic and/or episodic adverse impacts
on native brook trout are possible. Model hindcasts suggested that none of these streams had ANC less than 50 μeq/L in 1900.
Model projections, based on atmospheric emissions controls representative of laws already enacted as of 2003, suggested that
the ANC of those streams simulated to have experienced the largest historical decreases in ANC will increase in the future.
The levels of S deposition that were simulated to cause streamwater ANC to increase or decrease to three specified critical
levels (0, 20, and 50 μeq/L) ranged from less than zero (ANC level not attainable) to several hundred kg/ha/year, depending
on the selected site and its inherent acid-sensitivity, selected ANC endpoint criterion, and evaluation year for which the
critical load was calculated. Several of the modeled streams situated on siliciclastic geology exhibited critical loads <0 kg/ha/year
to achieve ANC >50 μeq/L in the year 2040, probably due at least in part to base cation losses from watershed soil. The median
modeled siliciclastic stream had a calculated critical load to achieve ANC >50 μeq/L in 2100 that was about 3 kg/ha/year,
or 77% lower than deposition in 1990, representing the time of model calibration. 相似文献
612.
Iannuzzi TJ Armstrong TN Long ER Iannuzzi J Ludwig DF 《Environmental monitoring and assessment》2008,139(1-3):257-275
The lower Passaic River in northern New Jersey (USA) has been heavily industrialized since the mid-nineteenth century and
its shoreline and aquatic habitats degraded or destroyed. Similar to other urban systems, Passaic River sediments, both surface
and buried, historically have contained elevated levels of numerous contaminants that may pose risks to ecological receptors
and humans. Sediments from 15 stations in the lower Passaic River and 3 reference stations in the Mullica River in southern
New Jersey were sampled in 1999 and characterized for chemical contamination, toxicity, and impairment of the benthic community.
The objective of this study was to determine the incidence, degree, and nature of degraded surficial sediments in the area
to support subsequent plans for restoration of the system. Results demonstrated that Passaic River sediments had concentrations
of many organic and inorganic contaminants at levels significantly greater than the reference area and effect-based guidelines.
Sediments were toxic to marine amphipods at 11 stations and the benthic assemblages were impaired relative to the reference
area at all stations. The weight-of-evidence of this sediment quality triad (SQT) assessment indicates that impacts from multiple
contaminants are occurring throughout the lower Passaic River and, that these impacts must be evaluated further and addressed
as part of ongoing restoration initiatives for the river. 相似文献
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在新的历史形势下,坚持以人为本,全面协调、可持续发展,走生态文明道路,是油田全面实现又好又快发展的必然选择,也是今后一段时间环境保护工作的关键。文章结合实际,论证了绿色生态油田建设的必要性,提出了创建的指导思想和基本原则,从改善环境质量、建立循环经济模式、完善生态管理机制、培育生态文化等方面对创建措施进行探讨。 相似文献
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采出水经处理后通常需作为地层回注水使用,由于油气生产的特殊性,常用的H2S脱除方法在使用中受到限制,探索适合于油气田生产的水处理方法十分必要。文章探讨了通常可用于油田采出水中H2S脱除的各种方法,对比了各类方法的优缺点,提出以NaClO为主要脱硫剂的水处理方法,通过对模拟采出水的室内实验,证明次氯酸法可以快速有效地去除采出水中的H2S,使H2S残留量低于1 mg/L。实验表明:经处理后的水质可以达到SY/T 5329-2012《碎屑岩油藏注水水质指标及分析方法》要求,处理成本较低。 相似文献
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619.
通过对江汉油田采油废水水质分析以及混凝实验研究,分析采油作业返排液中主要化学组分对含油废水混凝处理效果的影响,探讨了混凝剂、常用油田化学品与浊度及油含量去除率的关系,初步分析了它们的作用机理。研究表明,在钻井液中,单宁、磺化酚醛树脂(SMP)等对含油废水处理的影响很大,在压裂液中瓜胶、重铬酸钾等的影响较大,酸化液中乙酸和柠檬酸等的影响较大,射孔液中盐酸等的影响较大。本研究的结果对于消除返排液对油田生产的不良影响,保证系列增储上产措施的实施及其有效性,避免环境污染,具有十分重要的参考价值。 相似文献
620.