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121.
An experimental testing program designed to evaluate the opening stability characteristics of direct acting pressure relief valves (PRV) in gas/vapor service is described. Three different valve sizes from each of three different manufacturers were tested at two different set pressures to determine their opening characteristics (disk lift vs. time). The valves were tested with several different lengths of inlet piping as well as with and without discharge piping to determine the conditions under which unstable operation (chatter) would occur. Part I of this program described a mathematical model for predicting the dynamic response of PRV's, and the data described in this test program were used to evaluate the accuracy of the model, as described in Part III of this study to follow. 相似文献
122.
Reed F. Noss Jennifer M. Cartwright Dwayne Estes Theo Witsell Gregg Elliott Daniel Adams Matthew Albrecht Ryan Boyles Patrick Comer Chris Doffitt Don Faber-Langendoen JoVonn Hill William C. Hunter Wesley M. Knapp Michael E. Marshall Jason Singhurst Christopher Tracey Jeffrey Walck Alan Weakley 《Conservation biology》2021,35(6):1715-1724
Despite its successes, the U.S. Endangered Species Act (ESA) has proven challenging to implement due to funding limitations, workload backlog, and other problems. As threats to species survival intensify and as more species come under threat, the need for the ESA and similar conservation laws and policies in other countries to function efficiently has grown. Attempts by the U.S. Fish and Wildlife Service (USFWS) to streamline ESA decisions include multispecies recovery plans and habitat conservation plans. We address species status assessment (SSA), a USFWS process to inform ESA decisions from listing to recovery, within the context of multispecies and ecosystem planning. Although existing SSAs have a single-species focus, ecosystem-based research can efficiently inform multiple SSAs within a region and provide a foundation for transition to multispecies SSAs in the future. We considered at-risk grassland species and ecosystems within the southeastern United States, where a disproportionate number of rare and endemic species are associated with grasslands. To initiate our ecosystem-based approach, we used a combined literature-based and structured World Café workshop format to identify science needs for SSAs. Discussions concentrated on 5 categories of threats to grassland species and ecosystems, consistent with recommendations to make shared threats a focus of planning under the ESA: (1) habitat loss, fragmentation, and disruption of functional connectivity; (2) climate change; (3) altered disturbance regimes; (4) invasive species; and (5) localized impacts. For each threat, workshop participants identified science and information needs, including database availability, research priorities, and modeling and mapping needs. Grouping species by habitat and shared threats can make the SSA process and other planning processes for conservation of at-risk species worldwide more efficient and useful. We found a combination of literature review and structured discussion effective for identifying the scientific information and analysis needed to support the development of multiple SSAs. Article impact statement: Species status assessments can be improved by an ecosystem-based approach that groups imperiled species by shared habitats and threats. 相似文献
123.
气候资金测量、报告和核证产生于《联合国气候变化框架公约》(简称《公约》)之下,2009年以来一直是全球气候谈判的重点之一,也是未来全球共同应对气候变化和不断增进国际信任的重要环节。《巴黎协定》达成的"每两年通报"的决定,将推动气候资金测量、报告和核证得到不断的加强和完善。本文通过梳理最新的气候资金机制以及测量、报告和核证的文献资料和智库报告,分析了气候资金测量、报告和核证的内涵、目标和最新进展,以及公约框架下面临的挑战。分析指出,目前不同的气候资金统计和核算机构的资金分类标准存在差异,数据可比性有待改善;缺乏从资金上游到下游的反馈机制,影响气候资金测量、报告和核证体系的完整性;气候资金计量体系虽然正在发展和完善之中,但仍然难以提供准确的资金"支付"数据。据此,文章提出了构建综合性的国际气候资金测量、报告和核证体系的重点任务:建立具有统一数据基础和核算口径的气候资金测量体系,建立操作指南更为详细、形式更为标准统一的气候资金报告体系,以及"自上而下"和"自下而上"相结合的气候资金核证机制。最后,文章指出国际气候资金测量、报告和核证体系的构建需要发达国家和发展中国家在坚持公约资金机制的基础上共同参与和协作。作为国际上少数几个向GEF捐资的发展中国家之一,中国在参与过程中应力争体现发展中国家对气候资金性质的主张以及对测量、报告和核证机制的关键概念和范围界定的主张,影响国际气候资金机制的运营规则和技术规则。 相似文献
124.
Jan Karlas 《环境政策》2017,26(5):825-846
Why do some states and state coalitions, acting within the United Nations Framework Convention on Climate Change (UNFCCC), support harder legalization of the global climate regime? In order to explain why, the effects of four causal factors are considered: climate vulnerability, the emission intensity of the national economy, a state’s power position, and socialization into climate norms. To identify the legalization positions of UNFCCC actors, an original content analysis is conducted of all the submission and meeting statements made at the Ad Hoc Working Group on the Durban Platform during the years 2012–2015. Subsequently, a qualitative comparative analysis is carried out to find out which combinations of the causal factors offer a sufficient explanation for the analyzed outcome, leading to the identification of two causal pathways that lead states to endorse harder legalization of the climate regime. 相似文献
125.
Energy efficiency and conservation for individual Americans 总被引:1,自引:0,他引:1
D. Pimentel Jennifer Gardner Adam Bonnifield Ximena Garcia Julie Grufferman Claire Horan Julia Schlenker Emily Walling Emily Rochon 《Environment, Development and Sustainability》2009,11(3):523-546
Americans make up only 4% of the world population, yet currently consume 25% of the world’s fossil fuels. The U.S. imports
63% of its oil and it is predicted that by 2020 the U.S. will be importing 95% of its oil resources. Over the past century,
ample and affordable supplies of fossil fuels have powered the growth and prosperity of the economies of the US and other
countries. Within this century, world oil supplies will decline while demand is projected to continue to increase, suggesting
that we will have to transition to different fuels or become much more energy efficient or both. Looking ahead to the near
decades, estimates are that consumers will have to reduce their energy use by at least 50%. This reduction will be necessary
in large part due the decline in the availability of conventional oil and gas, but also because the U.S. population will continue
to grow in number. Although government action is important, individuals too often discount their ability to make significant
contributions to solving such major problems. This investigation identifies how informed and concerned individuals can collectively
conserve fossil energy.
Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.
An erratum to this article can be found at 相似文献
126.
127.
通过对我区废水处理设施运转情况的调查分析,得出废水处理设施运转效率低是由于设计水平低,施工质量差,设备管理不善及领导不重视等原因所致。 相似文献
128.
美国露天采矿环境保护标准及其对我国的借鉴意义 总被引:2,自引:1,他引:1
概述了美国露天采矿环境保护标准并总结其特点:(1)一般性和特殊性相结合;(2)采矿破坏地生态恢复涵义广,涉及矿区内所有受扰地区;(3)管理当局可针对具体矿山更改某些要求;(4)有完善的配套法规保障标准的执行。基于美国在采矿环境保护方面的经验,提出了我国矿产开发生态保护与恢复标准制定的4点设想:(1)涵盖矿产开发造成生态影响的每一个环节和所有的受扰地区;(2)尽量考虑各种具体情况;(3)体现生态恢复的全面性;(4)完善相关法规,保障标准实施。 相似文献
129.
介绍了美国在如何通过源头消减、再循环利用、堆肥等措施提高城市固体废物回收利用率,采取城市固体废弃物填埋、废弃物能量回收等方面的众多举措以减少废物的最终处置量.并阐述了在提高城市固体废物收集效率、降低日常运营成本等方面所做出的探索努力,促使美国城市固体废物的回收利用走上了良性循环的发展道路,对中国城市固体废物的日常管理及发展方向具有一定的参考借鉴作用. 相似文献
130.