全文获取类型
收费全文 | 739篇 |
免费 | 30篇 |
国内免费 | 23篇 |
专业分类
安全科学 | 85篇 |
废物处理 | 10篇 |
环保管理 | 159篇 |
综合类 | 227篇 |
基础理论 | 106篇 |
环境理论 | 5篇 |
污染及防治 | 53篇 |
评价与监测 | 53篇 |
社会与环境 | 58篇 |
灾害及防治 | 36篇 |
出版年
2023年 | 9篇 |
2022年 | 16篇 |
2021年 | 16篇 |
2020年 | 24篇 |
2019年 | 20篇 |
2018年 | 23篇 |
2017年 | 23篇 |
2016年 | 21篇 |
2015年 | 24篇 |
2014年 | 28篇 |
2013年 | 50篇 |
2012年 | 38篇 |
2011年 | 70篇 |
2010年 | 42篇 |
2009年 | 57篇 |
2008年 | 49篇 |
2007年 | 44篇 |
2006年 | 40篇 |
2005年 | 27篇 |
2004年 | 19篇 |
2003年 | 22篇 |
2002年 | 10篇 |
2001年 | 16篇 |
2000年 | 18篇 |
1999年 | 10篇 |
1998年 | 17篇 |
1997年 | 14篇 |
1996年 | 12篇 |
1995年 | 4篇 |
1994年 | 1篇 |
1993年 | 6篇 |
1992年 | 1篇 |
1991年 | 4篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1984年 | 3篇 |
1983年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有792条查询结果,搜索用时 15 毫秒
91.
Using GIS to Generate Spatially Balanced Random Survey Designs for Natural Resource Applications 总被引:2,自引:0,他引:2
Theobald DM Stevens DL White D Urquhart NS Olsen AR Norman JB 《Environmental management》2007,40(1):134-146
Sampling of a population is frequently required to understand trends and patterns in natural resource management because financial
and time constraints preclude a complete census. A rigorous probability-based survey design specifies where to sample so that
inferences from the sample apply to the entire population. Probability survey designs should be used in natural resource and
environmental management situations because they provide the mathematical foundation for statistical inference. Development
of long-term monitoring designs demand survey designs that achieve statistical rigor and are efficient but remain flexible
to inevitable logistical or practical constraints during field data collection. Here we describe an approach to probability-based
survey design, called the Reversed Randomized Quadrant-Recursive Raster, based on the concept of spatially balanced sampling
and implemented in a geographic information system. This provides environmental managers a practical tool to generate flexible
and efficient survey designs for natural resource applications. Factors commonly used to modify sampling intensity, such as
categories, gradients, or accessibility, can be readily incorporated into the spatially balanced sample design. 相似文献
92.
郝英君 《中国环境管理干部学院学报》2014,(6):84-88
采用资料收集、实地调研、调查问卷等方法,对环境保护领域人才需求情况以及岗位知识技能的要求、环境专业毕业生的就业意向进行调查和分析。结果表明,企业对高职环保人才需求量较大,环保人员应具备的素质以分析问题能力和沟通能力为主;高职院校环境专业毕业生对目前环境保护行业就业形势认识清楚,对就业单位的环保人才素质需求分析正确,但求职过程中存在目标设定偏高等问题,因此,从课程设置、教学方法和就业指导方面提出措施。 相似文献
93.
《Environmental Communication: A Journal of Nature and Culture》2013,7(6):740-760
ABSTRACTEfforts to educate the general public about global warming and the potential policy solutions that could mitigate its effects have relied on the diffusion of facts. But, cognitive scientists have documented that psychologically distant events like global warming elicit less concern and motivation to act relative to immediate, proximal and certain events. This paper documents a quasi-experiment that tested the effect on attitudes of a television campaign that emphasized the temporally, geographically and socially proximal impacts of global warming on the ecosystems and business activity of a historically conservative area of the United States. The campaign aired on one cable provider. Subscribers of that and of competing providers in the same zip-codes were polled after the campaign. Respondents exposed to the campaign were more likely to believe that global warming is happening, to accept the scientific consensus, to be more concerned about impacts and more supportive of policy solutions. 相似文献
94.
John Lie 《Sustainability Science》2007,2(2):233-236
The paper explores the potential political impact of global climate change and, more generally, of natural disaster. Because
the affluent West has largely tamed the natural and the social domains, popular clamor for government to anticipate, prevent,
and redress disaster increases. I delineate several consequences of the new politics of disaster. 相似文献
95.
96.
我国公众环境保护意识的调查与分析 总被引:16,自引:2,他引:14
洪大用 《中国人口.资源与环境》1997,7(2):27-31
本文根据一次大规模的抽样调查资料,初步分析了我国公众环境保护意识的现状,认为从总体上看,公众的环保意识水平偏低;公众的环境资源况颇具特色;在经济发展与环境保护之间出现明显矛盾时,半数公众能够优先考虑环境保护;大多数公众认为环境保护与个人有关,但对个人的努力信心不足;超过七成的公众表示愿意为环境保护支付一定费用,但对高收入阶层普遍寄予较高的期望;公众有一定的依法保护环境的心理基础,但法律知识又非常缺乏。 相似文献
97.
/ To understand the total impact of humans on the carbon cycle, themodeling and quantifying of the transfer of carbon from terrestrial pools tothe atmosphere is becoming more critical. Using previously published data,this research sought to assess the change in carbon pools caused by humans inthe Lower Fraser Basin (LFB) in British Columbia, Canada, since 1827 anddefine the long-term, regional contribution of carbon to the atmosphere. Theresults indicate that there has been a transfer of 270 Mt of carbon frombiomass pools in the LFB to other pools, primarily the atmosphere. The majorlosses of biomass carbon have been from logged forests (42%), wetlands(14%), and soils (43%). Approximately 48% of the forestbiomass, almost 20% of the carbon of the LFB, lies within old-growthforest, which covers only 19% of the study area. Landfills are nowbecoming a major sink of carbon, containing 5% of the biomass carbonin the LFB, while biomass carbon in buildings, urban vegetation, mammals, andagriculture is negligible. Approximately 26% of logged forest biomasswould still be in a terrestrial biomass pool, leaving 238 Mt of carbon thathas been released to the atmosphere. On an area basis, this is 29 times theaverage global emissions of carbon, providing an indication of the pastcontributions of developed countries such as Canada to global warming andpossible contributions from further clearing of rainforest in both tropicaland temperate regions.KEY WORDS: Carbon pools; Global warming; Carbon release to atmosphere;Greenhouse effect 相似文献
98.
长江安徽江段及巢湖水患区环境地质问题突出 ,因洪涝诱发引起的地质灾害十分频繁 ,特别是在每年汛期持续的高水位影响下 ,形成堤基管涌、边岸崩塌、软土变形、散浸等 ,造成溃口成灾或渍水成涝 ,形成大面积的洪涝灾害。这一地区的水患问题的形成和发展受地质环境影响和控制。通过收集有关资料 ,对长江安徽江段及巢湖水患区环境地质特征及存在的主要问题进行了初步分析 ,提出水患区的形成主要受控于地质作用 ,泥沙淤积与地貌演化作用 ,人类活动及岸带变化和堤基变形作用。为有效地进行防洪治水规划 ,应开展与洪涝灾害发生与发展有关的环境地质调查研究 ,特别是对江湖关系、第四纪地质和新构造运动与洪涝灾害的关系需要进行重点调查研究 ,为防洪治水规划提供依据。 相似文献
99.
A robust approach for iterative contaminant source location and release history recovery 总被引:1,自引:0,他引:1
Contamination source identification is a crucial step in environmental remediation. The exact contaminant source locations and release histories are often unknown due to lack of records and therefore must be identified through inversion. Coupled source location and release history identification is a complex nonlinear optimization problem. Existing strategies for contaminant source identification have important practical limitations. In many studies, analytical solutions for point sources are used; the problem is often formulated and solved via nonlinear optimization; and model uncertainty is seldom considered. In practice, model uncertainty can be significant because of the uncertainty in model structure and parameters, and the error in numerical solutions. An inaccurate model can lead to erroneous inversion of contaminant sources. In this work, a constrained robust least squares (CRLS) estimator is combined with a branch-and-bound global optimization solver for iteratively identifying source release histories and source locations. CRLS is used for source release history recovery and the global optimization solver is used for location search. CRLS is a robust estimator that was developed to incorporate directly a modeler's prior knowledge of model uncertainty and measurement error. The robustness of CRLS is essential for systems that are ill-conditioned. Because of this decoupling, the total solution time can be reduced significantly. Our numerical experiments show that the combination of CRLS with the global optimization solver achieved better performance than the combination of a non-robust estimator, i.e., the nonnegative least squares (NNLS) method, with the same solver. 相似文献
100.
以某城市为例,研究城市建筑泥浆的污染现状,并分析泥浆受到污染的原因.结果表明:对照《地表水环境质量标准》(GB 3838-2002)中的Ⅳ类标准限值,调研的4个工地泥浆水全部超标;该城市地层土壤中的有机质、总氮、总磷含量高是泥浆水超标的重要原因,工地制浆使用的地表水和污水也不能满足Ⅳ类水质的要求.在建筑工地的管理中,应... 相似文献