首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   93792篇
  免费   1236篇
  国内免费   1097篇
安全科学   3641篇
废物处理   3512篇
环保管理   14394篇
综合类   21120篇
基础理论   26776篇
环境理论   72篇
污染及防治   16154篇
评价与监测   5702篇
社会与环境   4149篇
灾害及防治   605篇
  2022年   755篇
  2021年   828篇
  2020年   660篇
  2019年   867篇
  2018年   1226篇
  2017年   1263篇
  2016年   2208篇
  2015年   1843篇
  2014年   2567篇
  2013年   9215篇
  2012年   2378篇
  2011年   2832篇
  2010年   3357篇
  2009年   3503篇
  2008年   2431篇
  2007年   2239篇
  2006年   2555篇
  2005年   2513篇
  2004年   2785篇
  2003年   2620篇
  2002年   2180篇
  2001年   2454篇
  2000年   1965篇
  1999年   1504篇
  1998年   1344篇
  1997年   1335篇
  1996年   1476篇
  1995年   1608篇
  1994年   1488篇
  1993年   1333篇
  1992年   1336篇
  1991年   1311篇
  1990年   1255篇
  1989年   1222篇
  1988年   1065篇
  1987年   1001篇
  1986年   998篇
  1985年   1066篇
  1984年   1165篇
  1983年   1171篇
  1982年   1177篇
  1981年   1100篇
  1980年   942篇
  1979年   937篇
  1978年   832篇
  1977年   723篇
  1976年   639篇
  1975年   610篇
  1973年   652篇
  1972年   649篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Environmental Economics and Policy Studies - Streets are an essential element of cities, and their design has a profound impact on their functionality to the movement of people and their...  相似文献   
92.
93.
Environmental Science and Pollution Research - Lake Mariut Main Basin (MB) is not only one of the three basins composing Lake Mariut (LM) but is also the main source of the popular tilapia fish to...  相似文献   
94.
Russian Journal of Ecology - In the southern tip of the Urals, late spring frosts, which regularly damage the leaves of the common oak (Quercus robur L.), are reflected in the formation of a...  相似文献   
95.
Environmental Chemistry Letters - Pollution of waters by azo dyes is a major global issue because some azo dyes have carcinogenic and mutagenic effects. Therefore, advanced methods are required to...  相似文献   
96.
Scientists in higher education institutions around the globe recognize the importance of engaging with public stakeholders to share their enthusiasm, explain their science, and encourage primary and secondary students to enter the sciences. However, without direct consideration of students’ and teachers’ perspectives and interests, scientists may design activities around their own goals, limiting the impact on school stakeholders (i.e., students, teachers, paraprofessional staff, students’ parents, and other caregivers). We drew from natural and social science research to describe how expanding the conception of place beyond the biophysical can help engage school stakeholders in meaningful ways. We describe the multidimensional PLACE framework that we developed to integrate perspectives, knowledge, and values of all stakeholders in engagement programming. The framework is organized around topics that stakeholders should discuss early on to ensure successful partnerships. We recommend that scientists identify and use pedagogy that is inclusive; language framed around dialogic communication methods; aims and motivations centered on engagement; cultural funds of knowledge of place (i.e., disciplinary, personal, or experiential knowledge); and evaluation of engagement based on meaningful metrics. Two case studies are presented to illustrate how the PLACE framework components, when addressed, can lead to robust, successful partnerships between scientists and schools.  相似文献   
97.
Understanding human behavior is vital to developing interventions that effectively lead to proenvironmental behavior change, whether the focus is at the individual or societal level. However, interventions in many fields have historically lacked robust forms of evaluation, which makes it hard to be confident that these conservation interventions have successfully helped protect the environment. We conducted a systematic review to assess how effective nonpecuniary and nonregulatory interventions have been in changing environmental behavior. We applied the Office of Health Assessment and Translation systematic review methodology. We started with more than 300,000 papers and reports returned by our search terms and after critical appraisal of quality identified 128 individual studies that merited inclusion in the review. We classified interventions by thematic area, type of intervention, the number of times audiences were exposed to interventions, and the length of time interventions ran. Most studies reported a positive effect (n = 96). The next most common outcome was no effect (n = 28). Few studies reported negative (n = 1) or mixed (n = 3) effects. Education, prompts, and feedback interventions resulted in positive behavior change. Combining multiple interventions was the most effective. Neither exposure duration nor frequency affected the likelihood of desired behavioral change. Comparatively few studies tested the effects of voluntary interventions on non-Western populations (n = 17) or measured actual ecological outcome behavior (n = 1). Similarly, few studies examined conservation devices (e.g., energy-efficient stoves) (n = 9) and demonstrations (e.g., modeling the desired behavior) (n = 5). There is a clear need to both improve the quality of the impact evaluation conducted and the reporting standards for intervention results.  相似文献   
98.
Ecologically relevant traits of organisms in an assemblage determine an ecosystem's functional fingerprint (i.e., the shape, size, and position of multidimensional trait space). Quantifying changes in functional fingerprints can therefore provide information about the effects of diversity loss or gain through time on ecosystem condition and is a promising approach to monitoring ecological integrity. This, however, is seldom possible owing to limitations in historical surveys and a lack of data on organismal traits, particularly in diverse tropical regions. Using data from detailed bird surveys from 4 periods across more than a century, and morphological and ecological traits of 233 species, we quantified changes in the avian functional fingerprint of a tropical montane forest in the Andes of Colombia. We found that 78% of the variation in functional space, regardless of period, was described by 3 major axes summarizing body size, dispersal ability (indexed by wing shape), and habitat breadth. Changes in species composition significantly altered the functional fingerprint of the assemblage and functional richness and dispersion decreased 35–60%. Owing to species extirpations and to novel additions to the assemblage, functional space decreased over time, but at least 11% of its volume in the 2010s extended to areas of functional space that were unoccupied in the 1910s. The assemblage now includes fewer large-sized species, more species with greater dispersal ability, and fewer habitat specialists. Extirpated species had high functional uniqueness and distinctiveness, resulting in large reductions in functional richness and dispersion after their loss, which implies important consequences for ecosystem integrity. Conservation efforts aimed at maintaining ecosystem function must move beyond seeking to sustain species numbers to designing complementary strategies for the maintenance of ecological function by identifying and conserving species with traits conferring high vulnerability such as large body size, poor dispersal ability, and greater habitat specialization. Article impact statement: Changes in functional fingerprints provide a means to quantify the integrity of ecological assemblages affected by diversity loss or gain.  相似文献   
99.
Land managers decide how to allocate resources among multiple threats that can be addressed through multiple possible actions. Additionally, these actions vary in feasibility, effectiveness, and cost. We sought to provide a way to optimize resource allocation to address multiple threats when multiple management options are available, including mutually exclusive options. Formulating the decision as a combinatorial optimization problem, our framework takes as inputs the expected impact and cost of each threat for each action (including do nothing) and for each overall budget identifies the optimal action to take for each threat. We compared the optimal solution to an easy to calculate greedy algorithm approximation and a variety of plausible ranking schemes. We applied the framework to management of multiple introduced plant species in Australian alpine areas. We developed a model of invasion to predict the expected impact in 50 years for each species-action combination that accounted for each species’ current invasion state (absent, localized, widespread); arrival probability; spread rate; impact, if present, of each species; and management effectiveness of each species-action combination. We found that the recommended action for a threat changed with budget; there was no single optimal management action for each species; and considering more than one candidate action can substantially increase the management plan's overall efficiency. The approximate solution (solution ranked by marginal cost-effectiveness) performed well when the budget matched the cost of the prioritized actions, indicating that this approach would be effective if the budget was set as part of the prioritization process. The ranking schemes varied in performance, and achieving a close to optimal solution was not guaranteed. Global sensitivity analysis revealed a threat's expected impact and, to a lesser extent, management effectiveness were the most influential parameters, emphasizing the need to focus research and monitoring efforts on their quantification.  相似文献   
100.
Journal of Polymers and the Environment - In the present investigation, the influence of coir micro-particles and titanium carbide (TiC) nanofillers on mechanical characteristics and thermal...  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号