全文获取类型
收费全文 | 34108篇 |
免费 | 361篇 |
国内免费 | 266篇 |
专业分类
安全科学 | 1100篇 |
废物处理 | 1625篇 |
环保管理 | 4351篇 |
综合类 | 5145篇 |
基础理论 | 8698篇 |
环境理论 | 10篇 |
污染及防治 | 8444篇 |
评价与监测 | 2498篇 |
社会与环境 | 2659篇 |
灾害及防治 | 205篇 |
出版年
2023年 | 154篇 |
2022年 | 304篇 |
2021年 | 367篇 |
2020年 | 217篇 |
2019年 | 282篇 |
2018年 | 503篇 |
2017年 | 546篇 |
2016年 | 829篇 |
2015年 | 608篇 |
2014年 | 980篇 |
2013年 | 2834篇 |
2012年 | 1169篇 |
2011年 | 1546篇 |
2010年 | 1251篇 |
2009年 | 1311篇 |
2008年 | 1612篇 |
2007年 | 1548篇 |
2006年 | 1384篇 |
2005年 | 1241篇 |
2004年 | 1181篇 |
2003年 | 1128篇 |
2002年 | 1070篇 |
2001年 | 1253篇 |
2000年 | 898篇 |
1999年 | 537篇 |
1998年 | 416篇 |
1997年 | 440篇 |
1996年 | 442篇 |
1995年 | 519篇 |
1994年 | 431篇 |
1993年 | 381篇 |
1992年 | 418篇 |
1991年 | 390篇 |
1990年 | 378篇 |
1989年 | 366篇 |
1988年 | 323篇 |
1987年 | 273篇 |
1986年 | 285篇 |
1985年 | 280篇 |
1984年 | 305篇 |
1983年 | 278篇 |
1982年 | 298篇 |
1981年 | 250篇 |
1980年 | 199篇 |
1979年 | 215篇 |
1978年 | 182篇 |
1977年 | 155篇 |
1975年 | 162篇 |
1973年 | 192篇 |
1972年 | 166篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
741.
A. V. Krylov 《Russian Journal of Ecology》2004,35(5):316-323
The abundance and trophic structure of zooplankton along the longitudinal profile of two typical rivers in the Yaroslavl sector of the Volga region are determined by anthropogenic and zoogenic factors. The distribution of zooplankton under the influence of these factors is described by the concept of patch dynamics. The abundance of zooplankton reaches the highest values in the ameliorated upper reaches of rivers and in beaver ponds. 相似文献
742.
Paul A.Steenhof 《中国人口.资源与环境(英文版)》2005,3(2)
1 INTRODUCTIONEnergy and environmental issues in China have receivedsignificant attention in both the peer-reviewed literatureand in international energy and environmental policymaking in the last number of years. China's coal dominatedenergy consumption results in significant regional pollutionproblems, most notably acid rain that affects nearly 1/3rdof China's landmass and air pollution that plagues manyof its major cities. China now ranks as the top emitterof sulphur dioxide (SO2) pol… 相似文献
743.
Golubev AV Golubeva VN Krylov NG Kuznetsova VF Mavrin SV Aleinikov AY Hoppes WG Surano KA 《Journal of environmental radioactivity》2005,84(3):333-342
Lichens are widely used to assess the atmospheric pollution by heavy metals and radionuclides. However, few studies are available in publications on using lichens to qualitatively assess the atmospheric pollution levels. The paper presents research results applying epiphytic lichens as bio-monitors of quantitative atmospheric contamination with uranium. The observations were conducted during 2.5 years in the natural environment. Two experimental sites were used: one in the vicinity of a uranium contamination source, the other one - at a sufficient distance away to represent the background conditions. Air and lichens were sampled at both sites monthly. Epiphytic lichens Hypogimnia physodes were used as bio-indicators. Lichen samples were taken from various trees at about 1.5m from the ground. Air was sampled with filters at sampling stations. The uranium content in lichen and air samples as well as isotopic mass ratios (235)U/(238)U were measured by mass-spectrometer technique after uranium pre-extraction. Measured content of uranium were 1.45 mgkg(-1) in lichen at 2.09 E-04 microgm(-3) in air and 0.106 mgkg(-1) in lichen at 1.13 E-05 microgm(-3) in air. The relationship of the uranium content in atmosphere and that in lichens was determined, C(AIR)=exp(1.1 x C(LICHEN)-12). The possibility of separate identification of natural and man-made uranium in lichens was demonstrated in principle. 相似文献
744.
A. B. Martynenko 《Russian Journal of Ecology》2006,37(1):53-59
Species richness, taxonomic diversity, and qualitative composition of the butterfly fauna (Lepidoptera, Diurna) are discussed in the light of data on the altitudinal zonality of local faunas in the southern Far East and Transbaikalia. It is shown that qualitative elevation-dependent changes in the fauna occur only in the western and northern parts of the region. 相似文献
745.
Trends in the anthropogenic transformation of flora in the city of Astrakhan and its environs over the past 100 years are discussed. In general, the process of flora synanthropization is observed, with natural aboriginal plant communities being replaced by anthropogenically altered communities. 相似文献
746.
747.
748.
The periodicity of fires in larch forests of Evenkia and their relationship with landscape elements have been studied. Cross-sections with “burns” in them caused by past fires have been analyzed in 72 test plots; the fire chronology encompassed the period from the 15th to the 20th century. The between-fire intervals (BFIs) have been calculated by two methods: (I) on the basis of burns alone and (II) on the basis of burns and the start of growth of the new generation of larch after the earliest fire. The BFI depends on local orographic features; it is 86 ± 11 (105 ± 12), 61 ± 8 (73 ± 8), 139 ± 17 (138 ± 18), and 68 ± 14 (70 ± 13) years for northeastern slopes, southwestern slopes, bogs, and flatlands, respectively. The mean BFIs calculated by methods I and II are 82 ± 7 and 95 ± 7 years, respectively. The permafrost horizon rises at a mean rate of 0.3 cm per year after a forest fire. It has been shown that the number of fires regularly peaks at periods of 36 and 82 years. There is also a temporal trend in fire frequency: the mean BFI was approximately 100 years in the 19th century and 65 years in the 20th century. 相似文献
749.
750.
E. A. Snegin 《Russian Journal of Ecology》2005,36(1):33-40
The distribution pattern of the gastropod Bradybaena fruticum has been studied in a forest-steppe landscape. Analysis of the frequencies of polymorphic biochemical and conchological characters has yielded preliminary results on the characteristics of the species population structure whose formation was determined by a set of natural and anthropogenic factors.Translated from Ekologiya, No. 1, 2005, pp. 39–47.Original Russian Text Copyright © 2005 by Snegin. 相似文献