全文获取类型
收费全文 | 4803篇 |
免费 | 34篇 |
国内免费 | 58篇 |
专业分类
安全科学 | 101篇 |
废物处理 | 170篇 |
环保管理 | 541篇 |
综合类 | 1073篇 |
基础理论 | 1058篇 |
环境理论 | 4篇 |
污染及防治 | 1066篇 |
评价与监测 | 342篇 |
社会与环境 | 524篇 |
灾害及防治 | 16篇 |
出版年
2023年 | 29篇 |
2022年 | 71篇 |
2021年 | 87篇 |
2020年 | 41篇 |
2019年 | 54篇 |
2018年 | 93篇 |
2017年 | 83篇 |
2016年 | 157篇 |
2015年 | 82篇 |
2014年 | 169篇 |
2013年 | 379篇 |
2012年 | 166篇 |
2011年 | 225篇 |
2010年 | 166篇 |
2009年 | 207篇 |
2008年 | 188篇 |
2007年 | 209篇 |
2006年 | 162篇 |
2005年 | 151篇 |
2004年 | 129篇 |
2003年 | 147篇 |
2002年 | 133篇 |
2001年 | 136篇 |
2000年 | 101篇 |
1999年 | 68篇 |
1998年 | 35篇 |
1997年 | 43篇 |
1996年 | 33篇 |
1995年 | 59篇 |
1994年 | 37篇 |
1993年 | 38篇 |
1992年 | 39篇 |
1991年 | 38篇 |
1990年 | 53篇 |
1989年 | 40篇 |
1988年 | 29篇 |
1987年 | 31篇 |
1986年 | 24篇 |
1985年 | 32篇 |
1984年 | 29篇 |
1983年 | 38篇 |
1982年 | 29篇 |
1981年 | 42篇 |
1980年 | 31篇 |
1979年 | 33篇 |
1978年 | 25篇 |
1977年 | 25篇 |
1976年 | 28篇 |
1975年 | 28篇 |
1965年 | 23篇 |
排序方式: 共有4895条查询结果,搜索用时 15 毫秒
1.
2.
E Enan I G Berberian S el-Fiki M el-Masry O H Enan 《Journal of environmental science and health. Part. B》1987,22(2):149-170
Male Baladi rabbits were acutely and sub-chronically intoxicated with cyanofenphos and profenophos. The levels of cholesterol, triglycerides, B-lipoproteins and total proteins were determined in the serum, brain, spinal cord and sciatic nerve of rabbits. Moreover, the activities of alkaline phosphatase, acid phosphatase and glutamic-pyruvic transaminase were determined in the liver of the animals. The whole studies revealed that the biochemical constituents were highly affected by the tested insecticides. Also, the liver function suffered from adverse effects of the tested insecticides. 相似文献
3.
Although the household level is recognized as a potentially important area for the application of ecological footprint (EF) analysis, almost no work has been reported in the academic literature on EF analysis at this level. This paper describes the application of a new, diary-based data acquisition methodology used in a component approach to estimate the EF of a small number of households in Aberdeen, Scotland. Feedback from householders indicated that the diary proved useful in educating participants about their environmental impacts and made EF findings convincing. The methodology was, however, time consuming for both participants and researchers, and it is concluded that future household level applications of EF analysis might combine a simplified diary with other forms of data acquisition. Findings also suggest that the presentation of EF results alone is unlikely to promote more environmentally conscious attitudes amongst householders unless specific EF components are identified for the householder to act upon. 相似文献
4.
Population characteristics, individual life-history variables, feeding and vertical distribution of the mesopelagic fish Müller's pearlside Maurolicus muelleri collected in 1990 in Masfjorden, western Norway, are reported as well as environmental variables from the fjord. Minimum size at maturity was far smaller than reported from previous investigations in the same region. Fecundity was size-dependent and total egg numbers were higher than reported from other investigations of M. muelleri world wide, while the number of maturing eggs was far lower than observed in the same region earlier. Food concentration in the fjord was an order of magnitude lower than previous early summer observations, and several factors indicated that feeding opportunities may have been low for a long period. Daily feeding rate (g prey g-1 fish) decreased with increasing fish size. These observations fit well with a model of maximizing fitness by means of a flexible size at maturity. Minimum age at maturity seems to be achieved at the expense of fecundity. M. muelleri was concentrated in a 20 to 30 m deep sound scattering layer (SSL). The SSL stayed close to the surface during the night and at 100 to 180 m during the daytime. The vertical position of the SSL varied instantaneously with changes in surface light intensity, remaining at 10-3 to 10-4 mol m-1 s-1 at the top of the SSL. Stomach fullness was highest during the night; feeding intensity seems to have been peaked at dusk. Cladocerans were the main prey ranked by number, copepods by biomass. Intake of large copepods increased with fish size. 相似文献
5.
6.
7.
8.
9.
The Science of Nature - 相似文献
10.