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   22947篇
  免费   182篇
  国内免费   228篇
安全科学   569篇
废物处理   1108篇
环保管理   2685篇
综合类   3022篇
基础理论   6272篇
环境理论   4篇
污染及防治   6133篇
评价与监测   1826篇
社会与环境   1616篇
灾害及防治   122篇
  2023年   89篇
  2022年   206篇
  2021年   216篇
  2020年   140篇
  2019年   179篇
  2018年   426篇
  2017年   429篇
  2016年   691篇
  2015年   410篇
  2014年   588篇
  2013年   1764篇
  2012年   1049篇
  2011年   1059篇
  2010年   825篇
  2009年   813篇
  2008年   930篇
  2007年   1036篇
  2006年   930篇
  2005年   1079篇
  2004年   1213篇
  2003年   1091篇
  2002年   713篇
  2001年   948篇
  2000年   641篇
  1999年   414篇
  1998年   276篇
  1997年   252篇
  1996年   289篇
  1995年   280篇
  1994年   255篇
  1993年   233篇
  1992年   243篇
  1991年   215篇
  1990年   218篇
  1989年   223篇
  1988年   197篇
  1987年   158篇
  1986年   126篇
  1985年   138篇
  1984年   169篇
  1983年   153篇
  1982年   193篇
  1981年   134篇
  1980年   119篇
  1979年   152篇
  1978年   118篇
  1977年   107篇
  1976年   100篇
  1975年   85篇
  1974年   90篇
排序方式: 共有10000条查询结果,搜索用时 93 毫秒
61.
Weather variability has the potential to influence municipal water use, particularly in dry regions such as the western United States (U.S.). Outdoor water use can account for more than half of annual household water use and may be particularly responsive to weather, but little is known about how the expected magnitude of these responses varies across the U.S. This nationwide study identified the response of municipal water use to monthly weather (i.e., temperature, precipitation, evapotranspiration [ET]) using monthly water deliveries for 229 cities in the contiguous U.S. Using city‐specific multiple regression and region‐specific models with city fixed effects, we investigated what portion of the variability in municipal water use was explained by weather across cities, and also estimated responses to weather across seasons and climate regions. Our findings indicated municipal water use was generally well‐explained by weather, with median adjusted R2 ranging from 63% to 95% across climate regions. Weather was more predictive of water use in dry climates compared to wet, and temperature had more explanatory power than precipitation or ET. In response to a 1°C increase in monthly maximum temperature, municipal water use was shown to increase by 3.2% and 3.9% in dry cities in winter and summer, respectively, with smaller changes in wet cities. Quantifying these responses allows urban water managers to plan for weather‐driven variability in water use.  相似文献   
62.
63.
64.
65.
66.
67.
68.
The study addresses the potential of using concentrated solar power plants (CSPs) as a sustainable alternative of clean energy generation in the Mediterranean region and, in particular, in its North Africa shore. This location presents attractive conditions for the installation of CSPs, in particular high solar irradiation, good manpower concentration, and proximity and availability of water resources for condenser cooling. Energetic, exergetic, and economic analyses were conducted taking into consideration a particular type of CSPs - the parabolic trough concentrated solar power plant, which incorporates the most proven technology and it is already used in Southern Europe (Spain). In addition, the study considered the impact of project financing and incentives on the cost of energy. The combination of higher values for performance and potentially lower levelized cost of electricity (LCE) for the North Africa Mediterranean Rim than the South of Spain region can yield a very favorable return for the invested capital. Tripoli compared to Almeria presented superior performance and potentially lower LCE values ($0.18/kWh versus $0.22/kWh). This is significant, even when it is taken into consideration the fact that the plant in Tripoli, despite a relatively modest capacity factor of 34%, has a large gross power output of 173,886 MWhe. In addition, the implementation at the Tripoli location of a plant similar to the Anadsol plant has a slight advantage (2–3%) in terms of overall efficiency.  相似文献   
69.
70.
Environmental Science and Pollution Research - Cartagena Bay is an estuarine system located in the Caribbean Sea (Colombia, South America), that receives fresh water from Canal del Dique, which is...  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