全文获取类型
收费全文 | 88415篇 |
免费 | 1225篇 |
国内免费 | 1104篇 |
专业分类
安全科学 | 3729篇 |
废物处理 | 3242篇 |
环保管理 | 13715篇 |
综合类 | 21036篇 |
基础理论 | 25963篇 |
环境理论 | 72篇 |
污染及防治 | 13646篇 |
评价与监测 | 5352篇 |
社会与环境 | 3469篇 |
灾害及防治 | 520篇 |
出版年
2022年 | 796篇 |
2021年 | 797篇 |
2020年 | 649篇 |
2019年 | 862篇 |
2018年 | 1099篇 |
2017年 | 1134篇 |
2016年 | 2144篇 |
2015年 | 1824篇 |
2014年 | 2578篇 |
2013年 | 9240篇 |
2012年 | 2108篇 |
2011年 | 2259篇 |
2010年 | 3206篇 |
2009年 | 3341篇 |
2008年 | 1807篇 |
2007年 | 1667篇 |
2006年 | 2127篇 |
2005年 | 2154篇 |
2004年 | 2454篇 |
2003年 | 2340篇 |
2002年 | 1848篇 |
2001年 | 2075篇 |
2000年 | 1896篇 |
1999年 | 1468篇 |
1998年 | 1357篇 |
1997年 | 1338篇 |
1996年 | 1467篇 |
1995年 | 1552篇 |
1994年 | 1451篇 |
1993年 | 1300篇 |
1992年 | 1295篇 |
1991年 | 1268篇 |
1990年 | 1214篇 |
1989年 | 1181篇 |
1988年 | 1023篇 |
1987年 | 959篇 |
1986年 | 985篇 |
1985年 | 1056篇 |
1984年 | 1157篇 |
1983年 | 1169篇 |
1982年 | 1179篇 |
1981年 | 1097篇 |
1980年 | 946篇 |
1979年 | 921篇 |
1978年 | 824篇 |
1977年 | 725篇 |
1976年 | 645篇 |
1975年 | 604篇 |
1973年 | 626篇 |
1972年 | 630篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
311.
Laperdina T. G. Melnikova M. V. Koval A. T. Sidorov Y. F. Nagorny V. A. Ostapchuk V. I. 《环境科学学报(英文版)》2000,(Z1)
IntroductionSiberiaandtheFarEastaretheoldestandtherichestgold miningareasofRussia .Intensivegold miningherestartedinthebeginningofthe 19thcentury(Vyazelshchikov ,1963) .Forthemostpartgold bearingoresandsandswereprocessedwiththeuseofamalgamationmethodforgolde… 相似文献
312.
313.
The abundance patterns of ant communities were monitored with pitfall traps during 14 weeks in four northern California, dry farmed, apple orchards: an abandoned orchard undisturbed for 25 years, two ‘organically’ managed orchards, one with a cover crop of bell beans (Vicia faba) and grasses and the other kept clean of cover by discing, and a ‘commercial’ clean cultivated orchard sprayed with organophosphate insecticides. Six species of ants coexisted in the abandoned orchard, whereas only two species were found in the managed orchards. In both the organic and sprayed, clean cultivated systems, ants were more abundant in the orchard edges than in the vegetation-free centers. This trend was not apparent in the abandoned or organic cover orchards, where plant diversity in the center was similar to that of the edges. Ant predation on potato tuberworm larvae, Phthorimaea operculella, artificially placed on the orchard floor, declined with the intensity of management and vegetational simplication. A higher incidence of larval removal occurred in the edges than in the centers of the clean cultivated orchards. No noticeable populations of ants were detected on the trees in any of the orchards. Increased vegetational diversity and lack of disturbance appeared to affect ant locomotory activity and foraging efficiency by creating preferred sheltering and feeding sites. 相似文献
314.
315.
316.
P. K. Kuroda 《Die Naturwissenschaften》1983,70(11):536-539
Until recently, scientists believed that the chemical elements were synthesized only in stars. The discovery of the Oklo phenomenon in the Republic of Gabon in 1972 has revealed, however, that a nuclear “fire” had existed on the earth and largescale transmutations of the elements were occurring on our planet 1.7·109 years ago. The formation of natural (or Pre-Fermi) reactors is closely related to the appearance of life on our planet earth. The Pre-Fermi reactors were probably never formed until about 2·109 years ago, when oxygen was injected into the earth's atmosphere by a new generation of living organisms carrying out photosynthesis. 相似文献
317.
318.
Richard J. Stock M.D. 《黑龙江环境通报》1982,2(2):133-137
A case of fetal death secondary to a needle laceration during a second trimester amniocentesis is presented. The need for careful pathologic evaluation of fetuses lost subsequent to these procedures is stressed. 相似文献
319.
320.
U. S. von Euler 《Die Naturwissenschaften》1981,68(6):277-281
A short account is given of the events leading to the creation, after Alfred Nobel's death 1896, of the Nobel Foundation for the management of the funds, and of the Nobel committees in charge of the selection of the Prize winners in the five areas mentioned in the will. The impact of the various and partly recently added activities of the Nobel organizations on contemporary international scientific and cultural life is briefly discussed. 相似文献