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   33461篇
  免费   360篇
  国内免费   317篇
安全科学   927篇
废物处理   1455篇
环保管理   4303篇
综合类   5341篇
基础理论   8608篇
环境理论   15篇
污染及防治   8678篇
评价与监测   2448篇
社会与环境   2130篇
灾害及防治   233篇
  2022年   297篇
  2021年   318篇
  2020年   226篇
  2019年   282篇
  2018年   495篇
  2017年   523篇
  2016年   793篇
  2015年   590篇
  2014年   867篇
  2013年   2825篇
  2012年   1048篇
  2011年   1377篇
  2010年   1222篇
  2009年   1250篇
  2008年   1418篇
  2007年   1512篇
  2006年   1365篇
  2005年   1119篇
  2004年   1098篇
  2003年   1101篇
  2002年   1010篇
  2001年   1309篇
  2000年   961篇
  1999年   582篇
  1998年   431篇
  1997年   412篇
  1996年   461篇
  1995年   456篇
  1994年   426篇
  1993年   413篇
  1992年   411篇
  1991年   385篇
  1990年   386篇
  1989年   363篇
  1988年   327篇
  1987年   267篇
  1986年   255篇
  1985年   282篇
  1984年   308篇
  1983年   296篇
  1982年   317篇
  1981年   277篇
  1980年   253篇
  1979年   281篇
  1978年   211篇
  1977年   205篇
  1976年   160篇
  1974年   182篇
  1973年   163篇
  1972年   171篇
排序方式: 共有10000条查询结果,搜索用时 171 毫秒
1.
Russian Journal of Ecology - The dynamics of the species richness, breeding density, and structure of the community of birds occupying nest-boxes upon a 50-fold reduction of atmospheric emissions...  相似文献   
2.
Environmental Science and Pollution Research - A current environmental problem is the uncontrolled use of various pesticides that are harmful to the environment and public health. The herbicide...  相似文献   
3.
This article postulates strong endogenous relationships in lower income countries between institutional quality, financial development and sustained economic growth. These associations were investigated using the vector-error correction model (VECM) and Granger causality method for a sample of 79 countries from 2005 to 2022. The findings show that (1) these variables reinforce each other in the short run. (2) In the long run, both institutional quality and financial development can fuel economic growth. (3) The positive effect of institutional quality on economic growth is greater than that of financial development. Policy implications of these findings are that careful attention should be paid to co-development policies to enhance the institutional quality and the financial system in these economies. Policies should also consider economic growth strategies to enable sustainable economic growth rates.  相似文献   
4.
Russian Journal of Ecology - A new method for assessing the response of biota to climatic changes in the ecosystem has been tested. In the Central Forest Natural Biosphere Reserve, the average...  相似文献   
5.
The Science of Nature - We present the first study that compares phenological variation in parasite load and inflammatory response in a lizard with asynchronous male and female gonadal cycles....  相似文献   
6.
Effective management refers to the ability of a protected area or indigenous territory to meet its objectives, particularly as they relate to the protection of biodiversity and forest cover. Effective management is achieved through a process of consolidation, which among other things requires legally protecting sites, integrating sites into land‐use planning, developing and implementing management and resource‐use plans, and securing long‐term funding to pay for recurrent costs. Effectively managing all protected areas and indigenous territories in the Amazon may be needed to avoid a deforestation tipping point beyond which regional climatic feedbacks and global climate change interact to catalyze irreversible drying and savannization of large areas. At present, protected areas and indigenous territories cover 45.5% (3.55 million km2) of the Amazon, most of the 60–70% forest cover required to maintain hydrologic and climatic function. Three independent evaluations of a long‐term large‐scale philanthropic initiative in the Amazon yielded insights into the challenges and advances toward achieving effective management of protected areas and indigenous territories. Over the life of the initiative, management of sites has improved considerably, particularly with respect to management planning and capacity building, but few sites are effectively managed and many lack sufficient long‐term financing, adequate governance, support of nongovernmental organizations, and the means to withstand economic pressures. The time and money required to complete consolidation is still poorly understood, but it is clear that philanthropic funding is critical so long as essential funding needs are not met by governments and other sources, which could be on the order of decades. Despite challenges, it is encouraging that legal protection has expanded greatly and management of sites is improving steadily. Management of protected areas in other developing countries could be informed by improvements that have occurred in Amazonian countries.  相似文献   
7.
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   
8.
9.
10.
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