全文获取类型
收费全文 | 17570篇 |
免费 | 223篇 |
国内免费 | 149篇 |
专业分类
安全科学 | 499篇 |
废物处理 | 649篇 |
环保管理 | 2449篇 |
综合类 | 3369篇 |
基础理论 | 4394篇 |
环境理论 | 14篇 |
污染及防治 | 4335篇 |
评价与监测 | 1088篇 |
社会与环境 | 1015篇 |
灾害及防治 | 130篇 |
出版年
2022年 | 141篇 |
2021年 | 149篇 |
2020年 | 132篇 |
2019年 | 158篇 |
2018年 | 236篇 |
2017年 | 280篇 |
2016年 | 370篇 |
2015年 | 326篇 |
2014年 | 417篇 |
2013年 | 1445篇 |
2012年 | 542篇 |
2011年 | 730篇 |
2010年 | 572篇 |
2009年 | 652篇 |
2008年 | 722篇 |
2007年 | 764篇 |
2006年 | 702篇 |
2005年 | 574篇 |
2004年 | 551篇 |
2003年 | 566篇 |
2002年 | 510篇 |
2001年 | 569篇 |
2000年 | 447篇 |
1999年 | 261篇 |
1998年 | 217篇 |
1997年 | 214篇 |
1996年 | 225篇 |
1995年 | 236篇 |
1994年 | 229篇 |
1993年 | 216篇 |
1992年 | 230篇 |
1991年 | 218篇 |
1990年 | 215篇 |
1989年 | 185篇 |
1988年 | 164篇 |
1987年 | 142篇 |
1986年 | 171篇 |
1985年 | 163篇 |
1984年 | 166篇 |
1983年 | 172篇 |
1982年 | 166篇 |
1981年 | 169篇 |
1980年 | 157篇 |
1979年 | 154篇 |
1978年 | 114篇 |
1977年 | 124篇 |
1974年 | 113篇 |
1973年 | 92篇 |
1972年 | 109篇 |
1971年 | 90篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
911.
912.
Behavior of dialifor, dimethoate, and methidathion in artificially fortified grape juice processed into wine. 总被引:1,自引:0,他引:1
N S Kawar Y Iwata M E Düsch F A Gunther 《Journal of environmental science and health. Part. B》1979,14(5):505-513
Dialifor and methidathion were added to diluted "Zinfandel" grape concentrate at 25 ppm and dimethoate at 1.0 and 25 ppm prior to fermentation with Saccharomyces cerevisiae. The finished wine 56 days later contained 10% (2.5 ppm) of the dialifor, 46% (12 ppm) of the methidathion and 85% (21 and 0.98 ppm) of the dimethoate added to the grape must. Residues in wine stored at 24 degrees C dissipated by hydrolysis; half-lives in wine were 7 days for dialifor and methidathion and 30 days for dimethoate. Residues were unchanged in wine in frozen storage for one year. Analysis of seven commercial wines for dimethoate indicated less than 0.03 ppm dimethoate was present; identity could not be confirmed by thin-layer chromatography at this level. 相似文献
913.
The effects of predominant currents on the morphology of coral reefs has been studied in the leeward patch reefs of Anegada, British Virgin Islands. Measurements of current velocity and direction and sediment characteristics together with mapping of approximately 31 patch reefs within a 2 km2 area suggest that even under relatively low but constant current velocities (surface current 20 cm sec-1) the major reef-building corals show definite distribution patterns on the reef. The currents also appear to be responsible, in part, for marked orientation and elongation of patch reefs in a north-west/ south-east direction and for a gradation of patch-reef type across the study area. 相似文献
914.
915.
916.
917.
918.
919.
920.
Dilution of indoor air contaminants with less contaminated outdoor air is the most common strategy for control of indoor air quality. Unfortunately this strategy frequently imposes a substantial energy burden. If the contaminants are associated with occupants and their activities, a ventilation control system based on the carbon dioxide level in the controlled space is shown to relieve this energy burden. A test was carried out in the Fridley, MN, Junior High School Music Department to obtain air quality, energy, and subjective response data on an Automatic Variable Ventilation System. A control system with both CO2 and temperature inputs was devised to control the use of outdoor air. Infiltration measurements lead to a quantitative measure of ventil3tion efficiency. This in turn led to recommendations for air circulation patterns in rooms. The measured ventilation efficiency enabled energy and CO2 models to fit measured data. Energy savings of approximately 20% were found for this application. Subjective response of the occupants also was measured. A special questionnaire, subjected to statistical analysis, showed that the subjects felt warmer with increased CO2 in the room air. 相似文献