全文获取类型
收费全文 | 801篇 |
免费 | 101篇 |
国内免费 | 168篇 |
专业分类
安全科学 | 93篇 |
废物处理 | 13篇 |
环保管理 | 196篇 |
综合类 | 402篇 |
基础理论 | 175篇 |
环境理论 | 2篇 |
污染及防治 | 86篇 |
评价与监测 | 12篇 |
社会与环境 | 66篇 |
灾害及防治 | 25篇 |
出版年
2024年 | 5篇 |
2023年 | 14篇 |
2022年 | 29篇 |
2021年 | 29篇 |
2020年 | 26篇 |
2019年 | 33篇 |
2018年 | 33篇 |
2017年 | 30篇 |
2016年 | 39篇 |
2015年 | 37篇 |
2014年 | 36篇 |
2013年 | 61篇 |
2012年 | 64篇 |
2011年 | 50篇 |
2010年 | 39篇 |
2009年 | 33篇 |
2008年 | 50篇 |
2007年 | 75篇 |
2006年 | 41篇 |
2005年 | 42篇 |
2004年 | 43篇 |
2003年 | 30篇 |
2002年 | 26篇 |
2001年 | 27篇 |
2000年 | 25篇 |
1999年 | 22篇 |
1998年 | 15篇 |
1997年 | 10篇 |
1996年 | 19篇 |
1995年 | 18篇 |
1994年 | 17篇 |
1993年 | 3篇 |
1992年 | 4篇 |
1991年 | 2篇 |
1990年 | 7篇 |
1989年 | 5篇 |
1988年 | 5篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1980年 | 2篇 |
1979年 | 3篇 |
1977年 | 2篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 2篇 |
1971年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有1070条查询结果,搜索用时 125 毫秒
71.
A method for evaluating areas for national park status 总被引:1,自引:0,他引:1
Sümer Gülez 《Environmental management》1992,16(6):811-818
A procedure for evaluating different areas as national parks based on a scoring system is proposed. A National Park Evaluation
Form (NPEF) evaluating natural, cultural, and recreational resources in accordance with international criteria for national
parks is presented. The evaluation points given to an area indicate the possibility of the area becoming a national park.
In this method, subjectivity and bias have been minimized by a special application of the Delphi technique. The method outlined
here could help in the efforts of selecting and establishing national parks in many countries. 相似文献
72.
城市土地资产经营新思路探讨 总被引:5,自引:0,他引:5
康雄华 《中国人口.资源与环境》2003,13(4):60-63
自1996年上海市成立第一家土地收购储备机构——土地发展中心后,全国各大城市已纷纷效仿它的成功经验。截止2001年8月不完全统计,全国已有大小不同的土地收购储备机构669家。实践证明,土地收购储备机制在盘活城市存量土地,促进土地集约利用,保障城市土地资产的保值增值等方面成绩卓著。然而,实践过程中,土地收购储备机制的运作也暴露出不少问题。本文通过对这些问题的分析,提出了引进公司制度完善土地收购储备机制,合理运营城市土地资产的新思路。 相似文献
73.
74.
Methods for life cycle assessment of products (LCA) are most often based on the general prevention principle, as opposed to the risk minimization principle. Here, the desirability and feasibility of a combined approach are discussed, along with the conditions for elaboration in the framework of LCA methodology, and the consequences for LCA practice. A combined approach provides a separate assessment of above and below threshold pollution, offering the possibility to combat above threshold impacts with priority. Spatial differentiation in fate, exposure, and effect modelling is identified to play a central role in the implementation. The collection of region-specific data turns out to be the most elaborate requirement for the implementation in both methodology and practice. A methodological framework for the construction of characterization factors is provided. Along with spatial differentiation of existing parameters, two newly introduced spatial parameters play a key role: the sensitivity factor and the threshold factor. The practicability of the proposed procedure is illustrated by an example of its application. Providing a reasonable data availability, the development of separate LCA characterization factors for the respective assessment of pollution levels above and below environmental threshold values seems to be a feasible task that may add to LCA credibility. 相似文献
75.
Lake Erie water quality has improved dramatically since the degraded conditions of the 1960s. Additional gains could be made,
but at the expense of further investment and reductions in fishery productivity. In facing such cross-jurisdictional issues,
natural resource managers in Canada and the United States must grapple with conflicting objectives and important uncertainties,
while considering the priorities of the public that live in the basin. The techniques and tools of decision analysis have
been used successfully to deal with such decision problems in a range of environmental settings, but infrequently in the Great
Lakes. The objective of this paper is to illustrate how such techniques might be brought to bear on an important, real decision
currently facing Lake Erie resource managers and stakeholders: the choice of new phosphorus loading targets for the lake.
The heart of our approach is a systematic elicitation of stakeholder preferences and an investigation of the degree to which
different phosphorus-loading policies might satisfy ecosystem objectives. Results show that there are potential benefits to
changing the historical policy of reducing phosphorus loads in Lake Erie. 相似文献
76.
黄腐酸的萃取和性质研究 总被引:3,自引:0,他引:3
黄腐酸是腐植酸中最具活力的组成部分,蕴藏量丰富,萃取方法简便。研究了从红原1#泥炭中萃取黄腐酸和降解物。它的分子量较小,易溶于水,抗絮凝性能好,分子内含有较多的活性官能团,具有很高的化学活性和生物活性,用途广泛。 相似文献
77.
An Exploration of the Value of Naturalness and Wild Nature 总被引:2,自引:0,他引:2
Ben Ridder 《Journal of Agricultural and Environmental Ethics》2007,20(2):195-213
The source of the value of naturalness is of considerable relevance for the conservation movement, to philosophers, and to
society generally. However, naturalness is a complex quality and resists straightforward definition. Here, two interpretations
of what is “natural” are explored. One of these assesses the naturalness of species and ecosystems with reference to a benchmark
date, such as the advent of industrialization. The value of naturalness in this case largely reflects prioritization of the
value of biodiversity. However, the foundation of our understanding of naturalness is that it describes processes that are
free of human intervention. Conflict between the two interpretations of naturalness is apparent in the claim that naturalness
can be enhanced by human intervention, in the form of ecological restoration. Although naturalness in its purest form precludes
human intervention, some human activities are also apparently more natural than others. This continuum of naturalness relates
to the autonomy of the individual from abstract instrumentalism, which describes a particular form of influence ubiquitous
in contemporary society. The value of naturalness reflects both dissatisfaction with these threats to personal autonomy, and
respect for wild nature as the embodiment of a larger-than-human realm. 相似文献
78.
Marion Babcock Bruce Mitchell 《Journal of the American Water Resources Association》1980,16(3):532-537
ABSTRACT: This study is an examination of the relationship between flooding and property values for an urban community in southwestern Ontario which has a lengthy history of flooding. As well, peoples’perceptions of the effect of flooding on property values is discussed. Analysis of sales prices and assessment data demonstrated no statistically significant differences in values of property for residences located in high- and low-risk areas either before or after a major flood in 1974. With both the high- and low-risk areas, sales prices after the 1974 flood were significantly higher than sales prices before the flood. The perceived property values followed a similar pattern. We concluded that differences in flood risk and flood experience did not adversely affect actual or perceived long-term property values. 相似文献
79.
LFB是Basofil纤维与Metmax纤维混合制成的针刺毡,本文主要介绍Basofil纤维和LFB的物理和化学特性。 相似文献
80.
ROBYN S. WILSON 《Conservation biology》2008,22(6):1452-1460
Abstract: Despite advances in the quality of participatory decision making for conservation, many current efforts still suffer from an inability to bridge the gap between science and policy. Judgment and decision‐making research suggests this gap may result from a person's reliance on affect‐based shortcuts in complex decision contexts. I examined the results from 3 experiments that demonstrate how affect (i.e., the instantaneous reaction one has to a stimulus) influences individual judgments in these contexts and identified techniques from the decision‐aiding literature that help encourage a balance between affect‐based emotion and cognition in complex decision processes. In the first study, subjects displayed a lack of focus on their stated conservation objectives and made decisions that reflected their initial affective impressions. Value‐focused approaches may help individuals incorporate all the decision‐relevant objectives by making the technical and value‐based objectives more salient. In the second study, subjects displayed a lack of focus on statistical risk and again made affect‐based decisions. Trade‐off techniques may help individuals incorporate relevant technical data, even when it conflicts with their initial affective impressions or other value‐based objectives. In the third study, subjects displayed a lack of trust in decision‐making authorities when the decision involved a negatively affect‐rich outcome (i.e., a loss). Identifying shared salient values and increasing procedural fairness may help build social trust in both decision‐making authorities and the decision process. 相似文献