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   7759篇
  免费   267篇
  国内免费   1198篇
安全科学   331篇
废物处理   468篇
环保管理   591篇
综合类   2505篇
基础理论   1540篇
环境理论   7篇
污染及防治   2620篇
评价与监测   546篇
社会与环境   460篇
灾害及防治   156篇
  2024年   7篇
  2023年   123篇
  2022年   297篇
  2021年   345篇
  2020年   220篇
  2019年   165篇
  2018年   345篇
  2017年   351篇
  2016年   434篇
  2015年   327篇
  2014年   547篇
  2013年   714篇
  2012年   569篇
  2011年   617篇
  2010年   437篇
  2009年   384篇
  2008年   503篇
  2007年   438篇
  2006年   393篇
  2005年   310篇
  2004年   224篇
  2003年   209篇
  2002年   171篇
  2001年   148篇
  2000年   147篇
  1999年   118篇
  1998年   101篇
  1997年   88篇
  1996年   85篇
  1995年   77篇
  1994年   56篇
  1993年   45篇
  1992年   52篇
  1991年   22篇
  1990年   17篇
  1989年   10篇
  1988年   16篇
  1987年   5篇
  1985年   6篇
  1984年   5篇
  1980年   4篇
  1967年   4篇
  1966年   6篇
  1965年   4篇
  1964年   9篇
  1962年   4篇
  1959年   7篇
  1958年   16篇
  1957年   6篇
  1955年   3篇
排序方式: 共有9224条查询结果,搜索用时 15 毫秒
1.
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   
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.
Environmental Science and Pollution Research - The impact of high concentrations of air pollution on COVID-19 has been a major air quality and life safety issue in recent studies. This study aimed...  相似文献   
4.
Biomethane production through biogas upgrading is a promising renewable energy for some industries which could be part of the equilibrium needed with fossil fuels consumption to achieve a sustainable society. This paper presents a comprehensive list of biogas upgrading technologies focused on carbon dioxide removal as well as recent advances reported by researcher with wide expertise in this topic. Additionally, an extensive costs–performance comparison among the technologies studied is discussed. Among the different alternatives, chemical scrubbing stood out to achieve high biomethane purities while cryogenic technologies proved to be effective against methane losses. Regarding the different costs, water scrubbing and membrane separation seem to be the most affordable techniques.  相似文献   
5.
6.
可张孔曝气器曝气能耗试验研究   总被引:1,自引:0,他引:1  
通过试验研究,总结出可张孔曝气阻力损失的影响因素,以优化产品的结构设计参数,降低产品在工程应用中的能耗,获取更好的经济效益。  相似文献   
7.
The degree of individual or gender variation when exploiting food resources is an important aspect in the study of foraging ecology within a population. Previous information on non-breeding skimmers obtained through conventional methodologies suggested sex-related differences in prey species. In this study, stable isotope techniques were used to investigate the intraspecific segregation in diet and foraging habits of the Black Skimmer (Rynchops niger intercedens) at Mar Chiquita Coastal Lagoon (37°40′S, 57°22′W), Argentina. These results were compared with contemporary data on the trophic composition obtained by conventional methodologies. Blood samples were taken from birds captured with mist-nets during their non-breeding season. The isotopic signatures of skimmers showed a diet mainly composed of marine prey with some degree of estuarine fish intake. When comparing diet between sexes, males showed enrichment in 15N compared to females, while no differences were observed in 13C. The use of mixing models revealed differences in the relative composition of prey in the diet of male and female skimmers. This study highlights stable isotope analysis as a valuable tool to test inter-individual differences and sexual segregation in trophic ecology of Black Skimmers as compared to conventional methodologies. The results show a trophic segregation in the Black Skimmer during the non-breeding season that can be explained by differences in prey species and larger prey sizes of male skimmers. Our findings have significant implications for conservation since any environmental change occurring at wintering areas might have profound effects on several avian life-history traits, and could be different for males and females due to trophic segregation.  相似文献   
8.
9.
10.
防灾预案研究   总被引:1,自引:0,他引:1  
陆立德  徐旭初 《灾害学》1992,7(2):17-20
本文提出了防御灾害预案的五要素和逻辑结构,进而讨论了防灾预案的优化准则、制定程序等问题。  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