全文获取类型
收费全文 | 850篇 |
免费 | 103篇 |
国内免费 | 29篇 |
专业分类
安全科学 | 505篇 |
废物处理 | 17篇 |
环保管理 | 215篇 |
综合类 | 125篇 |
基础理论 | 32篇 |
环境理论 | 1篇 |
污染及防治 | 23篇 |
评价与监测 | 22篇 |
社会与环境 | 23篇 |
灾害及防治 | 19篇 |
出版年
2024年 | 3篇 |
2023年 | 11篇 |
2022年 | 11篇 |
2021年 | 19篇 |
2020年 | 32篇 |
2019年 | 46篇 |
2018年 | 35篇 |
2017年 | 40篇 |
2016年 | 45篇 |
2015年 | 49篇 |
2014年 | 46篇 |
2013年 | 110篇 |
2012年 | 46篇 |
2011年 | 59篇 |
2010年 | 36篇 |
2009年 | 71篇 |
2008年 | 32篇 |
2007年 | 45篇 |
2006年 | 51篇 |
2005年 | 31篇 |
2004年 | 43篇 |
2003年 | 19篇 |
2002年 | 11篇 |
2001年 | 12篇 |
2000年 | 17篇 |
1999年 | 9篇 |
1998年 | 9篇 |
1997年 | 6篇 |
1996年 | 6篇 |
1995年 | 5篇 |
1994年 | 5篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1990年 | 3篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 3篇 |
1986年 | 1篇 |
1984年 | 3篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1975年 | 1篇 |
1973年 | 2篇 |
1972年 | 1篇 |
排序方式: 共有982条查询结果,搜索用时 31 毫秒
971.
对环保技术工作的机理进行了研究,提出了适应全面深化改革要求的环保技术工作思路,以及国家治污先导技术研发储备制度的构想。 相似文献
972.
Sujay S. Kaushal Paul M. Mayer Philippe G. Vidon Rose M. Smith Michael J. Pennino Tamara A. Newcomer Shuiwang Duan Claire Welty Kenneth T. Belt 《Journal of the American Water Resources Association》2014,50(3):585-614
Nonpoint source pollution from agriculture and urbanization is increasing globally at the same time climate extremes have increased in frequency and intensity. We review >200 studies of hydrologic and gaseous fluxes and show how the interaction between land use and climate variability alters magnitude and frequency of carbon, nutrient, and greenhouse gas pulses in watersheds. Agricultural and urban watersheds respond similarly to climate variability due to headwater alteration and loss of ecosystem services to buffer runoff and temperature changes. Organic carbon concentrations/exports increase and organic carbon quality changes with runoff. Nitrogen and phosphorus exports increase during floods (sometimes by an order of magnitude) and decrease during droughts. Relationships between annual runoff and nitrogen and phosphorus exports differ across land use. CH4 and N2O pulses in riparian zones/floodplains predominantly increase with: flooding, warming, low oxygen, nutrient enrichment, and organic carbon. CH4, N2O, and CO2 pulses in streams/rivers increase due to similar factors but effects of floods are less known compared to base flow/droughts. Emerging questions include: (1) What factors influence lag times of contaminant pulses in response to extreme events? (2) What drives resistance/resilience to hydrologic and gaseous pulses? We conclude with eight recommendations for managing watershed pulses in response to interactive effects of land use and climate change. 相似文献
973.
Daniel L. Long Randel L. Dymond 《Journal of the American Water Resources Association》2014,50(4):977-987
This study examines the use of bioretention as a strategy to reduce the thermal impact associated with urban stormwater runoff in developing cold water stream watersheds. Temperature and flow data were collected during 10 controlled runs at a bioretention facility located in Blacksburg, Virginia. It was determined that bioretention has the ability to reduce the temperature of thermally charged stormwater runoff received from an asphalt surface. Significant reductions in peak and average temperatures (p < 0.001) were observed. However, this facility was unable to consistently reduce the temperature below the threshold for natural trout waters in Virginia. The ability of bioretention to reduce runoff volume and peak flow rate also serves to reduce the hydrothermal impact. An average thermal pollution reduction of nearly 37 MJ/m3 was calculated using an adopted threshold temperature of 20°C. Based on the results of this study, it was concluded that properly designed bioretention systems have the capability to reduce the thermal impact of urban stormwater runoff on cold water stream ecosystems. 相似文献
974.
On the choice of farm management practices after the reform of the Common Agricultural Policy in 2003 总被引:1,自引:0,他引:1
The Common Agricultural Policy (CAP) was fundamentally reformed in 2003. From 2005, farmers will receive decoupled income support payments instead of production premiums if basic standards for environment, food safety, animal health and welfare are met. Farmers are likely to adjust production and management practices to the new policy framework. We describe how this reform fits into the EU strategy of making agricultural production more environmentally friendly by concentrating on the financial aspects of the reforms. Using an agricultural sector model for Austria, we show that the reform will further decrease agricultural outputs, reduce farm inputs, lessen nitrogen surpluses and make environmentally friendly management practices more attractive for farmers. 相似文献
975.
输油管道动火的安全管理 总被引:2,自引:1,他引:2
针对东北管网30年来动火施工安全管理方面的经验,总结近年来在动火安全管理上采用的新的管理模式所取得的成效,提出石油管道企业风险程度最高的输油管道动火施工安全管理动火准备、动火施工投产的责任界面划分、动火施工投产组织机构的建立、施工现场的安全管理等一整套科学动火方法和理念。通过对输油管道动火施工这一高风险作业管理实现了低风险操作,实现了本质安全。 相似文献
976.
California’s population increased 25% between 1980 and 1990, resulting in rapid and extensive urbanization. Of a total 123,000
ha urbanized in 42 of the state’s 58 counties between 1984 and 1990, an estimated 13% occurred on irrigated prime farmland,
and 48% on wildlands or fallow marginal farmlands. Sixty-six percent of all new irrigated farmland put into production between
1984 and 1990 was of lesser quality than the prime farmland taken out of production by urbanization. Factors dictating the
agricultural development of marginal farmlands include the availability and price of water and land, agricultural commodity
prices, and technical innovations such as drip irrigation systems that impact the feasibility and costs of production. The
increasing amount of marginal farmland being put into production could have significant water quality consequences because
marginal lands are generally steeper, have more erodible soils, poorer drainage, and require more fertilizer than prime farmlands.
Although no data exist to test our hypothesis, and numerous variables preclude definitive predictions, the evidence suggests
that new irrigated marginal lands can increase nonpoint source (NPS) pollution for a given size area by an order of magnitude
in some cases. 相似文献
977.
978.
对场地进行环境背景管理是确定区域污染状况、评价环境质量、进行污染预报、制定环境标准的基础。与背景管理相关的问题对于正确解释潜在污染场地的评估数据以及正确区别人为输入及背景贡献至关重要。缺乏对背景浓度的正确定义或错误理解背景浓度概念可导致错误鉴别潜在污染场地,或过高估计污染土壤的体积。因此,背景管理策略是场地环境评估不可分割的部分。介绍了环境背景值的制定方法及环境背景评估在场地环境评价中的作用,概述了欧洲不同国家(意大利、荷兰)、美国及加拿大有关背景管理的基本情况及相关国际标准惯例。 相似文献
979.
为提升企业本质安全水平,结合新时代新发展理念,中国石油推出“全员、全过程、全天候、全方位”抓安全生产工作的“四全”管理模式,实施“完善落实责任制、强化流程闭环管理、精准施策标本兼治和建立健全制度体系”等加强企业本质安全水平的各项举措,为提升企业安全管理水平、建设世界一流示范企业指明工作方向、提供管理保障。 相似文献
980.
While scholars have demonstrated that emotions play a central role in cognition, behavior, and decision making, most of the studies on emotions in work contexts show that emotions, or their expression, are often suppressed. We thus investigated how workers in high-stress work environments deal with emotions and remain functional by focusing on the range of extrinsic regulation strategies used by workers in these environments. Drawing from participant observations and in-depth, semistructured interviews, we show how police officers are flexible in their choices of emotion-regulation strategies and how contextual factors emerge as the crux of this process. We contribute to the understanding of regulatory flexibility—defined as the process of matching emotion regulation strategies to environmental circumstances as they unfold in real work situations—by identifying two main enabling factors: coregulation and third party interference. 相似文献