全文获取类型
收费全文 | 3258篇 |
免费 | 94篇 |
国内免费 | 1118篇 |
专业分类
安全科学 | 172篇 |
废物处理 | 210篇 |
环保管理 | 257篇 |
综合类 | 1733篇 |
基础理论 | 552篇 |
污染及防治 | 1202篇 |
评价与监测 | 106篇 |
社会与环境 | 103篇 |
灾害及防治 | 135篇 |
出版年
2024年 | 1篇 |
2023年 | 50篇 |
2022年 | 162篇 |
2021年 | 128篇 |
2020年 | 90篇 |
2019年 | 85篇 |
2018年 | 120篇 |
2017年 | 153篇 |
2016年 | 151篇 |
2015年 | 172篇 |
2014年 | 304篇 |
2013年 | 326篇 |
2012年 | 263篇 |
2011年 | 301篇 |
2010年 | 230篇 |
2009年 | 214篇 |
2008年 | 281篇 |
2007年 | 200篇 |
2006年 | 181篇 |
2005年 | 124篇 |
2004年 | 79篇 |
2003年 | 96篇 |
2002年 | 83篇 |
2001年 | 83篇 |
2000年 | 73篇 |
1999年 | 71篇 |
1998年 | 84篇 |
1997年 | 69篇 |
1996年 | 63篇 |
1995年 | 55篇 |
1994年 | 28篇 |
1993年 | 36篇 |
1992年 | 31篇 |
1991年 | 16篇 |
1990年 | 13篇 |
1989年 | 15篇 |
1988年 | 9篇 |
1987年 | 11篇 |
1986年 | 5篇 |
1985年 | 2篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1982年 | 1篇 |
1981年 | 3篇 |
1970年 | 1篇 |
排序方式: 共有4470条查询结果,搜索用时 140 毫秒
521.
In this paper, the amount of oxygen consumption, end products and activities of microorganisms are considered as the three factors which affect the biodegradability of organic substances in water. Two integrated assessment methods for biodegradability of organic substances, fuzzy clustering integrated assessment and weighted integrated assessment, have been developed. Simultaneously, the detail steps for assessing a new organic substance biodegradability with these two integrated assessment methods are proposed. 相似文献
522.
523.
524.
China's urban and rural populations face very serious health risks from combustion particles. Major sources of exposure to inhalable particulates include the burning solid fuels (biomass and coal) for household cooking and heating, coal-fired industrial and residential boilers, tobacco smoking, and diesel motor vehicles. China began to address particulate pollution problems over 25 years ago and has implemented a series of progressively more aggressive policies. This paper reviews the successes and limitations of past and existing policies for particulate controls, as well as the effects of China's economic reforms and energy policies on particulate exposure and pollution management. We examine the challenge of emissions reporting, required as part of both China's pollution levy system and emerging system for "total emissions control." Finally, we discuss practical steps toward exposure-based regulation of particulates, which would take advantage of the high cost-effectiveness for lifesaving of controlling particulate exposure from household and neighborhood sources relative to that of controlling exposure from industrial sources. 相似文献
525.
Plant uptake of aldicarb from contaminated soil and its enhanced degradation in the rhizosphere 总被引:3,自引:0,他引:3
Experiments were conducted to investigate the degradation of aldicarb, an oxime carbamate insecticide, in sterile, non-sterile and plant-grown soils, and the capability of different plant species to accumulate the pesticide. The degradation of aldicarb in soil followed first-order kinetics. Half lives (t1/2) of aldicarb in sterile and non-sterile soil were 12.0 and 2.7 days, respectively, which indicated that microorganisms played an important part in the degradation of aldicarb in soil. Aldicarb disappeared more quickly (p< or =0.05) in the soil with the presence of plants, and t1/2 of the pesticide were 1.6, 1.4 and 1.7 days in the soil grown with corn, mung bean and cowpea, respectively. Comparison of plant-promoted degradation and plant uptake showed that the enhanced removal of aldicarb in plant-grown soil was mainly due to plant-promoted degradation in the rhizosphere. 相似文献
526.
527.
528.
529.
530.