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   2512篇
  免费   37篇
  国内免费   50篇
安全科学   78篇
废物处理   86篇
环保管理   251篇
综合类   429篇
基础理论   577篇
环境理论   5篇
污染及防治   806篇
评价与监测   187篇
社会与环境   169篇
灾害及防治   11篇
  2023年   31篇
  2022年   73篇
  2021年   72篇
  2020年   35篇
  2019年   48篇
  2018年   133篇
  2017年   111篇
  2016年   168篇
  2015年   101篇
  2014年   140篇
  2013年   196篇
  2012年   140篇
  2011年   199篇
  2010年   115篇
  2009年   106篇
  2008年   149篇
  2007年   132篇
  2006年   117篇
  2005年   77篇
  2004年   81篇
  2003年   64篇
  2002年   53篇
  2001年   41篇
  2000年   29篇
  1999年   17篇
  1998年   12篇
  1997年   11篇
  1996年   13篇
  1995年   13篇
  1994年   8篇
  1993年   12篇
  1992年   7篇
  1991年   9篇
  1990年   7篇
  1989年   7篇
  1988年   8篇
  1985年   3篇
  1984年   3篇
  1983年   3篇
  1982年   4篇
  1981年   3篇
  1980年   6篇
  1977年   3篇
  1966年   4篇
  1965年   2篇
  1964年   4篇
  1961年   3篇
  1960年   2篇
  1959年   2篇
  1954年   2篇
排序方式: 共有2599条查询结果,搜索用时 545 毫秒
1.
Environmental Science and Pollution Research - There is mixed evidence surrounding the relationship between tobacco use and COVID-19 infection/progression. The current study investigates beliefs...  相似文献   
2.
Environmental Science and Pollution Research - Legacy (i.e., polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCDD)) and alternative halogenated flame retardants (HFRs) were...  相似文献   
3.
Journal of Material Cycles and Waste Management - This work presents an energy analysis of an industrial plant of production of Di-ammonium Phosphate (DAP plant). It aims to evaluate the important...  相似文献   
4.
This paper investigates the effects of the incorporation of lignin and small quantities of epoxidized natural rubber (ENR) as an impact modifying agent on blends of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and poly(ε-caprolactone) (PCL). The addition of lignin resulted in a slight improvement of flexural strength and modulus of the ternary blending system. Incorporation of ENR into the blend resulted in an increase in notched Izod impact strength from 40 to 135% depending on the concentration of ENR. The addition of lignin into the blend resulted in an improvement of thermal stability of the ternary blend system. Morphological analysis showed a good dispersion of PHBV phases and lignin within the PCL matrix. Rheological characterization revealed that the presence of lignin resulted in increased storage modulus of the bioblend.  相似文献   
5.
6.
Achieving coexistence between large carnivores and humans in human-dominated landscapes (HDLs) is a key challenge for societies globally. This challenge cannot be adequately met with the current sectoral approaches to HDL governance and an academic community largely dominated by disciplinary sectors. Academia (universities and other research institutions and organizations) should take a more active role in embracing societal challenges around conservation of large carnivores in HDLs by facilitating cross-sectoral cooperation to mainstream coexistence of humans and large carnivores. Drawing on lessons from populated regions of Europe, Asia, and South America with substantial densities of large carnivores, we suggest academia should better embrace the principles and methods of sustainability sciences and create institutional spaces for the implementation of transdisciplinary curricula and projects; reflect on research approaches (i.e., disciplinary, interdisciplinary, or transdisciplinary) they apply and how their outcomes could aid leveraging institutional transformations for mainstreaming; and engage with various institutions and stakeholder groups to create novel institutional structures that can respond to multiple challenges of HDL management and human–large carnivore coexistence. Success in mainstreaming this coexistence in HDL will rest on the ability to think and act cooperatively. Such a conservation achievement, if realized, stands to have far-reaching benefits for people and biodiversity.  相似文献   
7.
8.
Environmental Science and Pollution Research - The reduction of estrogen levels, as a result of menopause, is associated with the development of metabolic diseases caused by alterations in...  相似文献   
9.
Cornus stolonifera, Salix petiolaris, and Spiraea alba clones already located within the corridor of an electrical power line. To establish the efficiency of treatments, we examined the statistical differences of growth traits between species and treatments. An analysis of the effects of layering shows, after the first growth season, differences for all growth traits in only one species, Spiraea alba. After the second growth season, we observed the development of new aerial stems. Layering favors horizontal expansion of shrubs over height development. The third year after treatment, the effect of layering is reduced except for Cornus stolonifera, which continuously increases, as shown by the significant progression of the clone issued from the layer even five years after treatments. With the cutting back technique, we expected a distinct vertical growth of the shrubs at the expense of increasing the crown diameter. This technique would be best associated with the rejuvenation of clones, followed by a layering of new shoots to allow a horizontal expansion of the shrubs. Therefore, the formation of a dense shrub community by layering should be considered a valuable approach for the biological control of undesirable trees in powerline rights-of-way.  相似文献   
10.
Rapid and reliable methods for documenting soil erosion associated with forest harvest operations are needed to support the development of best management practices for soil and water conservation. To address this need, the potential for using 7Be measurements to estimate patterns and amounts of soil redistribution associated with individual post-harvest events was explored. The 7Be technique, which was originally developed for use on agricultural land, was employed to estimate soil redistribution associated with a period of heavy rainfall within a harvested forest area located in the Lake Region of Chile (39 degrees 44'7' S, 73 degrees 10'39' W; 22% slope; and mean annual rainfall 2300 mm yr(-1)). The results provided by the 7Be technique were validated against direct measurements of soil gain or loss during the same period obtained using erosion pins. The information produced by the two approaches was similar. The results of this study demonstrate the potential for using 7Be measurements to document event-based erosion in recently harvested forest areas.  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