全文获取类型
收费全文 | 1638篇 |
免费 | 35篇 |
国内免费 | 23篇 |
专业分类
安全科学 | 115篇 |
废物处理 | 81篇 |
环保管理 | 350篇 |
综合类 | 227篇 |
基础理论 | 374篇 |
污染及防治 | 359篇 |
评价与监测 | 127篇 |
社会与环境 | 52篇 |
灾害及防治 | 11篇 |
出版年
2023年 | 21篇 |
2022年 | 15篇 |
2021年 | 28篇 |
2020年 | 34篇 |
2019年 | 27篇 |
2018年 | 39篇 |
2017年 | 41篇 |
2016年 | 48篇 |
2015年 | 42篇 |
2014年 | 54篇 |
2013年 | 201篇 |
2012年 | 70篇 |
2011年 | 94篇 |
2010年 | 50篇 |
2009年 | 72篇 |
2008年 | 78篇 |
2007年 | 88篇 |
2006年 | 70篇 |
2005年 | 64篇 |
2004年 | 52篇 |
2003年 | 55篇 |
2002年 | 54篇 |
2001年 | 28篇 |
2000年 | 33篇 |
1999年 | 17篇 |
1998年 | 20篇 |
1997年 | 17篇 |
1996年 | 18篇 |
1995年 | 18篇 |
1994年 | 23篇 |
1993年 | 18篇 |
1992年 | 17篇 |
1991年 | 14篇 |
1990年 | 11篇 |
1989年 | 6篇 |
1988年 | 9篇 |
1987年 | 14篇 |
1986年 | 11篇 |
1985年 | 12篇 |
1984年 | 7篇 |
1983年 | 9篇 |
1982年 | 14篇 |
1981年 | 16篇 |
1980年 | 10篇 |
1979年 | 7篇 |
1978年 | 6篇 |
1977年 | 4篇 |
1976年 | 5篇 |
1956年 | 3篇 |
1955年 | 3篇 |
排序方式: 共有1696条查询结果,搜索用时 31 毫秒
141.
142.
The distribution of three important dissolved forms of nitrogen, viz. nitrate, nitrite and urea in the surface and bottom water samples collected from 27 selected hydrographic profiles, in the Arabian Sea, along the west coast of India is described. Of the three forms, nitrate concentrations were the highest and comparatively higher concentrations were observed in the bottom water. Decomposition of organic matter resulting in the release of the thermodynamically stable nitrogen species, i.e. nitrate, may be the major factor resulting in higher nitrate concentrations at these depths, where the water is also characterized by low values of dissolved oxygen and temperature. The significant positive correlation between A.O.U. and nitrate of the bottom water samples emphasizes the role of oxidative decomposition of organic matter which plays an active role in reducing the oxygen concentrations below the theoretical values since at this depth ( ≈200 m) the net production is taken to be zero. This is also evidenced by the negative correlation of nitrate with dissolved oxygen and temperature, for the bottom samples. 相似文献
143.
144.
Drivers under the age of 70 whose prior 4-year accident and conviction records showed no entries when examined 2 months prior to the date of expiration of their driver licenses were randomly assigned to either a group that renewed licenses in the normal manner or a group that was offered the opportunity to receive a 4-year license extension by mail. A related experiment involved comparing clean-record drivers of any age who were given a 2-year extension with a group of drivers required to renew in person. Examination of driver records 18 and 28 months subsequent to extension uncovered no deleterious effects of the program, while savings of roughly 3 million dollars annually are expected. Findings are tentative, however, until 4-year data can be collected. The report concludes that the extension program has been successful, that multiple extensions should be authorized and evaluated for drivers with continuing clean records, and that the present exclusion of drivers 70 and above does not appear to be defensible. 相似文献
145.
Breakthrough and retention volume studies have been done for a series of chlorocarbon compounds on Tenax GC adsorbent with results compared to data of other workers. Initial data indicates that carrier velocity (Time to establish equilibrium) may significantly effect retention of these chemicals. 相似文献
146.
147.
148.
Kathryn D. McGowan Joseph J. Weiser Juli Horwitz Sue Ann Berend Christopher McCaskill V. Reid Sutton Lisa G. Shaffer 《黑龙江环境通报》2002,22(2):141-143
We report the finding of paternal isodisomy for chromosome 14 in a fetus found to have a der(14;14)(q10;q10) by amniocentesis. The pregnancy was complicated by severe polyhydramnios and elevated amniotic fluid alpha-fetoprotein (AFP). The infant showed features consistent with paternal uniparental disomy (UPD) including postnatal growth retardation, poor respiratory function, feeding difficulties, and evidence of hypertrophic cardiomyopathy. The present case, in addition to other reported cases of UPD involving balanced acrocentric rearrangements, supports testing for UPD in prenatally detected Robertsonian translocations and isochromosomes. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
149.
The effects of pathway configuration, landmarks and stress on environmental cognition 总被引:1,自引:0,他引:1
Gary W. Evans Mary Anne Skorpanich Tommy Grling Kendall J. Bryant Brian Bresolin 《Journal of environmental psychology》1984,4(4):323-335
The results of this study indicate that manipulations of the pathway grid configuration and landmark placement in a setting cause changes in environmental knowledge. These experimental manipulations were accomplished using a realistic, dynamic simulation technique at the Berkeley Environmental Simulation Laboratory. Measures of environmental knowledge include: memory for incidental information along the simulated urban route, accuracy of route maps, relocation memory for scenes along the route, and questionnaire measures. Data are also presented showing both positive and negative effects of stress from noise on the processes of environmental cognition. 相似文献
150.