全文获取类型
收费全文 | 53421篇 |
免费 | 567篇 |
国内免费 | 648篇 |
专业分类
安全科学 | 1600篇 |
废物处理 | 2212篇 |
环保管理 | 6779篇 |
综合类 | 9523篇 |
基础理论 | 14420篇 |
环境理论 | 41篇 |
污染及防治 | 13665篇 |
评价与监测 | 3390篇 |
社会与环境 | 2648篇 |
灾害及防治 | 358篇 |
出版年
2022年 | 477篇 |
2021年 | 470篇 |
2020年 | 366篇 |
2019年 | 463篇 |
2018年 | 807篇 |
2017年 | 767篇 |
2016年 | 1165篇 |
2015年 | 928篇 |
2014年 | 1369篇 |
2013年 | 4095篇 |
2012年 | 1695篇 |
2011年 | 2323篇 |
2010年 | 1910篇 |
2009年 | 1955篇 |
2008年 | 2332篇 |
2007年 | 2437篇 |
2006年 | 2119篇 |
2005年 | 1778篇 |
2004年 | 1719篇 |
2003年 | 1765篇 |
2002年 | 1618篇 |
2001年 | 2074篇 |
2000年 | 1458篇 |
1999年 | 937篇 |
1998年 | 686篇 |
1997年 | 704篇 |
1996年 | 693篇 |
1995年 | 779篇 |
1994年 | 773篇 |
1993年 | 653篇 |
1992年 | 670篇 |
1991年 | 632篇 |
1990年 | 666篇 |
1989年 | 658篇 |
1988年 | 577篇 |
1987年 | 503篇 |
1986年 | 432篇 |
1985年 | 495篇 |
1984年 | 486篇 |
1983年 | 504篇 |
1982年 | 491篇 |
1981年 | 450篇 |
1980年 | 377篇 |
1979年 | 420篇 |
1978年 | 370篇 |
1977年 | 291篇 |
1976年 | 294篇 |
1975年 | 296篇 |
1974年 | 262篇 |
1972年 | 300篇 |
排序方式: 共有10000条查询结果,搜索用时 484 毫秒
991.
992.
C. Vaccarino G. Cimino M.M. Tripodo G. Lagan L. Lo Giudice R. Matarese 《Agriculture, ecosystems & environment》1983,10(3):275-283
Necrotic brown lesions developing on leaves and fruits of lemon, and other plants, near fossil-fuel-burning power plants emitting vanadium-rich ash, were reproduced experimentally by inoculating leaves with this type of ash, which is strongly acidic. Comparable lesions were formed when drops of vanadium oxide, dissolved in NaOH, were put on leaves and fruits. Neutralizing, or adding excess H2SO4 (to pH 3), did not alter lesion formation. The histology of these lesions was similar to that of lesions attributed to vanadium-rich ash. 相似文献
993.
994.
995.
We report relatively high citrulline concentration in amniotic fluid of a citrullinemic fetus suggesting that prenatal detection of this condition could be done on this basis in conjunction with a direct or an indirect determination of argininosuccinate synthetase activity in amniotic fluid cells. 相似文献
996.
997.
998.
A high-precision seismic reflection method has been developed for investigating archeological objects which are hidden in a mud-layer of the Haddebyer Noor, a lake in front of the old Viking settlement Haithabu near Schleswig. Wooden and metallic objects larger than about 30 cm could be detected and mapped. Some of the mapped objects have been rescued by diving operations. Others, like wooden harbour constructions of unexpectedly large dimensions, and a large (second) shipwrack were left conserved in the mud. All finds provide a new picture of this old Viking settlement showing that its inhabitants had a far higher stage of development than hitherto suspected. 相似文献
999.
Christian Klixbüll Jørgensen 《Die Naturwissenschaften》1982,69(9):420-427
The “constituents” quarks and leptons of matter (with rest-mass) are compared with the historical development of “elements” in chemistry. If unsaturated quarks induce high (and at the moment unpredictable) rest-masses above l0GeV, we have a new view of nuclei comprising (2Z + N) u-quarks and (Z +2N) d-quarks in their low-energy states, without any reference to protons and neutrons as permanent building-blocks. Recent studies of quarks and possible rishons (sub-quarks) and technicolour hadrons are reviewed, and the rôle of identity and cardinality in quantum mechanics analyzed. 相似文献
1000.