全文获取类型
收费全文 | 29386篇 |
免费 | 325篇 |
国内免费 | 220篇 |
专业分类
安全科学 | 792篇 |
废物处理 | 1060篇 |
环保管理 | 4018篇 |
综合类 | 4659篇 |
基础理论 | 8532篇 |
环境理论 | 21篇 |
污染及防治 | 7678篇 |
评价与监测 | 1741篇 |
社会与环境 | 1239篇 |
灾害及防治 | 191篇 |
出版年
2022年 | 157篇 |
2021年 | 178篇 |
2019年 | 214篇 |
2018年 | 387篇 |
2017年 | 378篇 |
2016年 | 554篇 |
2015年 | 489篇 |
2014年 | 677篇 |
2013年 | 2132篇 |
2012年 | 841篇 |
2011年 | 1249篇 |
2010年 | 1025篇 |
2009年 | 1032篇 |
2008年 | 1249篇 |
2007年 | 1329篇 |
2006年 | 1183篇 |
2005年 | 1004篇 |
2004年 | 1003篇 |
2003年 | 937篇 |
2002年 | 936篇 |
2001年 | 1239篇 |
2000年 | 842篇 |
1999年 | 535篇 |
1998年 | 420篇 |
1997年 | 430篇 |
1996年 | 438篇 |
1995年 | 482篇 |
1994年 | 438篇 |
1993年 | 390篇 |
1992年 | 414篇 |
1991年 | 373篇 |
1990年 | 376篇 |
1989年 | 411篇 |
1988年 | 347篇 |
1987年 | 300篇 |
1986年 | 276篇 |
1985年 | 305篇 |
1984年 | 286篇 |
1983年 | 321篇 |
1982年 | 322篇 |
1981年 | 271篇 |
1980年 | 243篇 |
1979年 | 269篇 |
1978年 | 229篇 |
1977年 | 195篇 |
1976年 | 200篇 |
1975年 | 192篇 |
1974年 | 172篇 |
1973年 | 171篇 |
1972年 | 198篇 |
排序方式: 共有10000条查询结果,搜索用时 203 毫秒
991.
Thomas Eisner Daniel J. Aneshansley Jayne Yack Athula B. Attygalle Maria Eisner 《Chemoecology》2001,11(4):209-219
Summary. The defensive glandular apparatus of primitive bombardier beetles of the tribe Crepidogastrini (Carabidae) is described for
the first time. As exemplified by two African species (Crepidogaster ambreana and C. atrata), the apparatus conforms to the basic bombardier plan, in that the glands are bicompartmented and the secretion is quinonoid
(it contains 1,4-benzoquinones and hydrocarbons), hot, and discharged audibly. In a number of morphological respects the crepidogastrine
apparatus resembles that of the classical bombardiers of the tribe Brachinini (rather than that of bombardiers of the paussoid
lineage), reinforcing the view, already held on taxonomic grounds, that the Crepidogastrini and Brachinini are closely related.
That the Crepidogastrini may be primitive relative to Brachinini is underscored by the finding that, unlike brachinines, crepidogastrines
do not pulse their secretory emissions. Moreover, they discharge their secretion as a mist, rather than forcibly in the form
of jets.
Received 22 May 2001; accepted 29 May 2001. 相似文献
992.
993.
Jun Liao Malini Sathanoori Svetlana A. Yatsenko Jie Hu Sally J. Kochmar Lori Hoffner W. Allen Hogge Urvashi Surti 《黑龙江环境通报》2012,32(12):1166-1169
994.
Jürgen Warrelmann Hartmut Kochler Tobias Frische Ingo Dobner Ulrich Walter Wolfgang Heyser 《Environmental Sciences Europe》2000,12(6):351-357
On the area of a former ordnance plant (‘Werk Tanne’, Clausthal-Zellerfeld, Germany), a field experiment for phytoremediation of TNT-contaminated soils has been carried out since May 1999. The concept is based on a stepwise degradation of TNT by white-rot fungi and mycorrhiza within the rhizosphere of site-specific seedlings. An appropiate site with contaminants in the surface-soil was prepared with a large-scale soil grader and subsequently divided into different experimental plots, including an uncontaminated control as well as a contaminated plot without treatment. Planting of the selected trees and shrubs (infected with mycorrhiza during nursery) and inoculation with wood chips (inoculated with white-rot fungi) is followed by a detailed monitoring of the experimental plots (chemical analyses, biotest-battery, ecological field indicators). For the evaluation of the results, multivariate methods are applied. 相似文献
995.
This paper attempts to explain regional differences in fertility rates in the standard metropolitan statistical areas of the United States through socioeconomic factors and air pollution. An important feature of this study is that it uses the most recent data pertaining to a homogeneous sample of observations within a country rather than using data for different countries. Statistical results suggest that given other factors, fertility and the level of air pollution have an inverse relationship. This quantitative effect is statistically significant but the absolute impact is rather low. Our results also suggest that an increase in the level of income, relative education of females, temperature, and the availability of physicians would in the long run reduce fertility rates in the urban areas of the United States. 相似文献
996.
997.
998.
E J Genetelli 《Journal - Water Pollution Control Federation》1967,39(10):Suppl:R32-Suppl:R44
999.
1000.
Potential concerns related to using octadecyltrichlorosilane (OTS) in rendering soils and porous ceramics hydrophobic 总被引:1,自引:0,他引:1
The treatment of hydrophilic porous ceramics to render them hydrophobic and wetting to non-aqueous phase liquids (NAPLs) is frequently needed in multiphase flow experiments to control the flow or to measure the pressure of the NAPL. In addition, research dealing with soil wettability implies a need for hydrophobic or NAPL-wet soils. The traditional procedure, which has been widely used in literature, to render hydrophilic porous ceramics and soils hydrophobic is achieved by placing the hydrophilic solid in a 5% (by volume) octadecyltrichlorosilane (OTS) solution in ethanol followed by rinsing in ethanol. This research assesses the use of this procedure as it was found that this treatment procedure resulted in excess OTS on the surface of treated hydrophobic solids which can dissolve in an organic phase and in turn alter the wettability condition of adjacent hydrophilic soils. A modified procedure, which results in hydrophobic solids free of excess OTS, is presented. 相似文献