全文获取类型
收费全文 | 10928篇 |
免费 | 106篇 |
国内免费 | 509篇 |
专业分类
安全科学 | 121篇 |
废物处理 | 833篇 |
环保管理 | 1331篇 |
综合类 | 1789篇 |
基础理论 | 3313篇 |
污染及防治 | 2057篇 |
评价与监测 | 1076篇 |
社会与环境 | 965篇 |
灾害及防治 | 58篇 |
出版年
2024年 | 8篇 |
2023年 | 22篇 |
2022年 | 80篇 |
2021年 | 73篇 |
2020年 | 74篇 |
2019年 | 54篇 |
2018年 | 1533篇 |
2017年 | 1432篇 |
2016年 | 1276篇 |
2015年 | 209篇 |
2014年 | 130篇 |
2013年 | 138篇 |
2012年 | 585篇 |
2011年 | 1466篇 |
2010年 | 803篇 |
2009年 | 683篇 |
2008年 | 965篇 |
2007年 | 1312篇 |
2006年 | 76篇 |
2005年 | 68篇 |
2004年 | 69篇 |
2003年 | 101篇 |
2002年 | 133篇 |
2001年 | 54篇 |
2000年 | 31篇 |
1999年 | 32篇 |
1998年 | 25篇 |
1997年 | 21篇 |
1996年 | 13篇 |
1995年 | 12篇 |
1994年 | 6篇 |
1993年 | 5篇 |
1992年 | 15篇 |
1991年 | 3篇 |
1990年 | 5篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 3篇 |
1984年 | 12篇 |
1983年 | 8篇 |
1935年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
61.
AsayofsomevolatilecompoundsinhumanexhalationQinTao,XuXiaobaiResearchCenterforEcoEnvironmentalSciences,ChineseAcademyofScie... 相似文献
62.
重庆大气可吸入颗粒物中多环芳烃的分析测定 总被引:4,自引:0,他引:4
本文报告了重庆大气可吸入颗粒物(IP)中多环芳烃(PAH)的分析测定方法和结果.用GC-MS定性和定量分析了重庆IP中的PAH;研究了IP中PAH的种类和分布情况;确认重庆IP中存在甲基多环芳烃(MePAH)、约占33%;颗粒大小分布表明,约有98%PAH存在于小于3μm的颗粒中. 相似文献
63.
64.
对杯形件单道次拉深旋压成形过程进行了分析,重点讨论了具有两个圆弧工作面的旋轮形状对成形过程的影响.研究结果表明,不同的旋轮形状不仅改变了旋压力p的大小,并且由于其对厚度应变ε的分布影响较大而造成整个旋压过程变形特征的改变,从而导致在工件的不同部位产生破裂. 相似文献
65.
Gamergates (i.e. mated reproductive workers) are mostly known from ant species within the Ponerinae. We report here the discovery of gamergates in two species of the subfamily Myrmicinae. Until now, mated reproductive females in colonies of myrmicine species have been considered morphologically distinct from the worker caste. However, in two species of the myrmicine Metapone (Metapone madagascarica and a newly discovered, not yet described Metapone species) all workers have six ovarioles and a spermatheca; and some of them are mated. There are no morphological differences between mated and non-mated workers. Field observations and laboratory studies indicate that colonies of the Metapone species can reproduce with gamergates only. 相似文献
66.
Although amphibians are highly vocal, they generally emit only a limited number of acoustic communication signals. We report here the extraordinarily rich vocal repertoire of Amolops tormotus, a ranid species in China. These frogs produce countless vocalizations, some of which share features of birdsong or primate calls, e.g., ultrasonic frequency components, multiple upward and downward FM sweeps, and sudden onset and offset of selective harmonic components within a call note. Frame-by-frame video analysis of the frog's calling behavior suggests the presence of two pairs of vocal sacs that may contribute to the remarkable call-note complexity in this species. Electronic supplementary material to this paper can be obtained by using the Springer LINK server located at http://dx.doi.org/10.1007/s00114-002-0335-x. 相似文献
67.
Aysen Müezzinoğlu Tolga Elbir Abdurrahman Bayram 《Environmental Engineering and Policy》1998,1(2):109-116
In this study, an inventory of air pollutant emission estimates from major air polluting sources in Turkey for period between 1985 and 2005 with 5-year intervals were estimated. Inventory covers anthropogenic sources of five major air pollutants of particulate matter, sulfur dioxide, carbon monoxide, nitrogen oxides and non-methane volatile organic compounds. Their break-down with respect to main activity sectors were shown and their distribution by the largest industrial source categories were worked out as annual estimates. This inventory and its analysis point to serious environmental implications of air pollutants and a need to develop a policy plan for reducing these emissions. 相似文献
68.
Independent teams undertook environmental monitoring of particular concentrations of major construction projects forming part of Hong Kong’s U.S. $20 billion airport infrastructure programme located in dense urban areas. The team combination of environmental specialists with experienced civil engineers enabled pragmatic mitigation measures to be developed and accepted by the construction personnel with the result that potentially significant adverse impacts were averted. The authors discuss the mechanism and success of this innovative approach. 相似文献
69.
根据2003年12月-2005年5月对大亚湾纬度22.563°以北海域进行的7个航次海域生态环境监测资料,对大亚湾水螅水母类的种类组成及优势种、数量分布、区系特征等作了探讨,结果表明:本次调查,大亚湾共出现水螅水母类40种,其中大洋性种有6种,其总N/O值为5.67,表明本海区水螅水母类的近岸性较强;四叶小舌水母(Liriope tetraphylla)是第一优势种,占水螅水母丰度的27.59%;大亚湾海域水螅水母类,其动物地理区划属印度-西太平洋区印-马亚区。 相似文献
70.