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   465篇
  免费   25篇
  国内免费   6篇
安全科学   41篇
废物处理   12篇
环保管理   115篇
综合类   56篇
基础理论   138篇
环境理论   3篇
污染及防治   66篇
评价与监测   31篇
社会与环境   27篇
灾害及防治   7篇
  2023年   10篇
  2022年   5篇
  2021年   8篇
  2020年   18篇
  2019年   12篇
  2018年   26篇
  2017年   19篇
  2016年   28篇
  2015年   27篇
  2014年   19篇
  2013年   32篇
  2012年   36篇
  2011年   31篇
  2010年   17篇
  2009年   33篇
  2008年   23篇
  2007年   27篇
  2006年   22篇
  2005年   13篇
  2004年   8篇
  2003年   13篇
  2002年   12篇
  2001年   4篇
  2000年   5篇
  1999年   2篇
  1998年   3篇
  1997年   2篇
  1996年   5篇
  1995年   3篇
  1994年   2篇
  1993年   2篇
  1992年   2篇
  1991年   1篇
  1988年   1篇
  1986年   2篇
  1985年   3篇
  1982年   3篇
  1981年   7篇
  1980年   6篇
  1978年   1篇
  1977年   2篇
  1976年   1篇
排序方式: 共有496条查询结果,搜索用时 15 毫秒
171.
Global efforts to deliver internationally agreed goals to reduce carbon emissions, halt biodiversity loss, and retain essential ecosystem services have been poorly integrated. These goals rely in part on preserving natural (e.g., native, largely unmodified) and seminatural (e.g., low intensity or sustainable human use) forests, woodlands, and grasslands. To show how to unify these goals, we empirically derived spatially explicit, quantitative, area-based targets for the retention of natural and seminatural (e.g., native) terrestrial vegetation worldwide. We used a 250-m-resolution map of natural and seminatural vegetation cover and, from this, selected areas identified under different international agreements as being important for achieving global biodiversity, carbon, soil, and water targets. At least 67 million km2 of Earth's terrestrial vegetation (∼79% of the area of vegetation remaining) required retention to contribute to biodiversity, climate, soil, and freshwater conservation objectives under 4 United Nations’ resolutions. This equates to retaining natural and seminatural vegetation across at least 50% of the total terrestrial (excluding Antarctica) surface of Earth. Retention efforts could contribute to multiple goals simultaneously, especially where natural and seminatural vegetation can be managed to achieve cobenefits for biodiversity, carbon storage, and ecosystem service provision. Such management can and should co-occur and be driven by people who live in and rely on places where natural and sustainably managed vegetation remains in situ and must be complemented by restoration and appropriate management of more human-modified environments if global goals are to be realized.  相似文献   
172.
We examine bottom-line mentality (BLM) at the group level and examine the effect of group BLM on group psychological safety and subsequent group creativity. We draw on goal shielding theory to suggest that groups high in BLM narrowly focus on bottom-line outcomes, which encourages them to eliminate distracting considerations from their work processes. Because the group's high BLM encapsulates goal shielding, these groups are deficient in fostering psychological safety as an important interpersonal process that facilitates group creativity. We also couple goal shielding theory with arguments related to situational strength to examine group BLM agreement (i.e., the standard deviation of the mean of group BLM) as a first stage moderator. We contend that high-BLM agreement (vs. low agreement) strengthens the goal shielding effect of group BLM, which is reflected by a stronger detrimental effect on group psychological safety that then reduces group creativity. We found support for our theoretical model using multisource, multiwave field data from a diverse sample of workgroups and their supervisors. We discuss the theoretical implications of our research and provide practical suggestions for limiting the deleterious consequences of group BLMs in the workplace.  相似文献   
173.
Environmental Management - This study examines the engagement of Vietnamese American commercial fisheries stakeholders in the US Gulf Coast with state and federal agencies and the role that citizen...  相似文献   
174.
Small-scale fisheries are an important livelihood and primary protein source for coastal communities in many of the poorest regions in the world, yet many are overfished and thus require effective and scalable management solutions. Positive ecological and socioeconomic responses to management typically lag behind immediate costs borne by fishers from fishing pressure reductions necessary for fisheries recovery. These short-term costs challenge the long-term success of these interventions. However, social marketing may increase perceptions of management benefits before ecological and socioeconomic benefits are fully realized, driving new social norms and ultimately long-term sustainable behavior change. By conducting underwater visual surveys to quantify ecological conditions and by conducting household surveys with community members to quantify their perceptions of management support and socioeconomic conditions, we assessed the impact of a standardized small-scale fisheries management intervention that was implemented across 41 sites in Brazil, Indonesia, and the Philippines. The intervention combines TURF reserves (community-based territorial use rights for fishing coupled with no-take marine reserves) with locally tailored social-marketing behavior change campaigns. Leveraging data across 22 indicators and 4 survey types, along with data from 3 control sites, we found that ecological and socioeconomic impacts varied and that communities supported the intervention and were already changing their fishing practices. These results suggest that communities were developing new social norms and fishing more sustainably before long-term ecological and socioeconomic benefits of fisheries management materialized.  相似文献   
175.
Communication of knowledge between the scientific and management communities is a difficult process complicated by the distinctive nature of professional career goals of scientists and decision-makers. This article provides a case history highlighting a collaboration between the science and management communities that resulted from a response to a 2004 hypoxia, or low dissolved oxygen, event in Long Bay, off Myrtle Beach, South Carolina. A working group of scientists and decision-makers was established at the time of the event and has continued to interact to develop a firm understanding of the drivers responsible for hypoxia formation in Long Bay. Several factors were found to be important to ensure that these collaborative efforts were productive: (1) genuine interest in collaboratively working across disciplines to examine a problem; (2) commitment by agency leadership, decision-makers, and researchers to create successful communication mechanisms; (3) respect for each others’ perspectives and an understanding how science and management are performed and that they are not mutually exclusive; (4) networking among researchers and decision-makers to ensure appropriate team members are involved in the process; (5) use of decision-maker input in the formulation of research and monitoring projects; and (6) commitment of resources for facilitation to ensure that researchers and decision-makers are communicating effectively.  相似文献   
176.
As natural resource management agencies and conservation organizations seek guidance on responding to climate change, myriad potential actions and strategies have been proposed for increasing the long-term viability of some attributes of natural systems. Managers need practical tools for selecting among these actions and strategies to develop a tailored management approach for specific targets at a given location. We developed and present one such tool, the participatory Adaptation for Conservation Targets (ACT) framework, which considers the effects of climate change in the development of management actions for particular species, ecosystems and ecological functions. Our framework is based on the premise that effective adaptation of management to climate change can rely on local knowledge of an ecosystem and does not necessarily require detailed projections of climate change or its effects. We illustrate the ACT framework by applying it to an ecological function in the Greater Yellowstone Ecosystem (Montana, Wyoming, and Idaho, USA)-water flows in the upper Yellowstone River. We suggest that the ACT framework is a practical tool for initiating adaptation planning, and for generating and communicating specific management interventions given an increasingly altered, yet uncertain, climate.  相似文献   
177.
Buchanan, Brian, Zachary M. Easton, Rebecca Schneider, and M. Todd Walter, 2011. Incorporating Variable Source Area Hydrology Into a Spatially Distributed Direct Runoff Model. Journal of the American Water Resources Association (JAWRA) 48(1): 43‐60. DOI: 10.1111/j.1752‐1688.2011.00594.x Abstract: Few hydrologic models simulate both variable source area (VSA) hydrology, and runoff‐routing at high enough spatial resolutions to capture fine‐scale hydrologic pathways connecting VSA to the stream network. This paper describes a geographic information system‐based operational model that simulates the spatio‐temporal dynamics of VSA runoff generation and distributed runoff‐routing, including through complex artificial drainage networks. The model combines the Natural Resource Conservation Service’s Curve Number (CN) equation for estimating storm runoff with the topographic index concept for predicting the locations of VSA and a runoff‐routing algorithm into a new spatially distributed direct hydrograph (SDDH) model (SDDH‐VSA). Using a small agricultural watershed in central New York, SDDH‐VSA results were compared to those from a SDDH model using the traditional land use assumptions for the CN (SDDH‐CN). The SDDH‐VSA model generally agreed better with observed discharge than the SDDH‐CN model (average, Nash‐Sutcliffe efficiency of 0.69 vs. 0.58, respectively) and resulted in more realistic spatial patterns of runoff‐generating areas. The SDDH approach did not correctly capture the timing of runoff from small storms in dry periods. Despite this type of limitation, SDDH‐VSA extends the applicability of the SDDH technique to VSA conditions, providing a basis for new tools to help identify critical management areas and assess water quality risks due to landscape alterations.  相似文献   
178.
This paper examines structural barriers to the adoption of climate change mitigation practices and the evolution of a climate change ethic among American farmers. It examines how seed corn contracts in Michigan constrain the choices of farmers and allow farmers to rationalize the over-application of fertilizer and associated water pollution and greenhouse gas emissions. Seed corn contracts use a competitive “tournament” system where farmers are rewarded for maximizing yields. Interviews and a focus group were used to understand fertilizer over-application and barriers to participating in a climate change mitigation program. Results indicate that farmers agree that they over-apply fertilizer but would be unlikely to participate in a mitigation program due to their contracts and lack of support from seed corn companies. Because only a few companies control access to the seed corn market, farmers feel they have few choices. Farmers rationalized their practices as their only option given the competitive nature of their contracts and blamed other sources of pollution. Despite increasing efforts to educate farmers about climate change, structural barriers will continue to constrain participation in mitigation efforts and the development of a climate change ethic.  相似文献   
179.
Scholars have noted that race and ethnicity, socio-economic status (SES) as well as other socio-demographic factors may limit participation in local food systems based on the historic and structured patterns of inequalities that remain in communities promoting alternative agriculture and food (agrifood) activities. However, few empirical studies have examined the barriers which prevent people from participating in local food system activities. This paper uses survey data from the 2008 Ohio Survey of Food, Agriculture and Environmental Issues to consider whether barriers such as interest, time, financial resources, geography and space impact the participation of households in home gardening. Results from logistic regression show that SES, the availability of space and housing type are important factors which limit or enable household participation in home gardening. This paper contributes to our understanding of the barriers that prevent households from participating in home gardening, a form of food system localisation that, while a potentially powerful way to transform the agrifood system, has been underexamined in its own right.  相似文献   
180.
This study investigated potential nitrogen fixation, net nitrification, and denitrification responses to short-term crude oil exposure that simulated oil exposure in Juncus roemerianus salt marsh sediments previously impacted following the Deepwater Horizon accident. Temperature as well as crude oil amount and type affected the nitrogen cycling rates. Total nitrogen fixation rates increased 44 and 194 % at 30 °C in 4,000 mg kg?1 tar ball and 10,000 mg kg?1 moderately weathered crude oil treatments, respectively; however, there was no difference from the controls at 10 and 20 °C. Net nitrification rates showed production at 20 °C and consumption at 10 and 30 °C in all oil treatments and controls. Potential denitrification rates were higher than controls in the 10 and 30?ºC treatments but responded differently to the oil type and amount. The highest rates of potential denitrification (12.7?±?1.0 nmol N g?1 wet h?1) were observed in the highly weathered 4,000 mg kg?1 oil treatment at 30 °C, suggesting increased rates of denitrification during the warmer summer months. These results indicate that the impacts on nitrogen cycling from a recurring oil spill could depend on the time of the year as well as the amount and type of oil contaminating the marsh. The study provides evidence for impact on nitrogen cycling in coastal marshes that are vulnerable to repeated hydrocarbon exposure.  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