全文获取类型
收费全文 | 996篇 |
免费 | 52篇 |
国内免费 | 325篇 |
专业分类
安全科学 | 45篇 |
废物处理 | 71篇 |
环保管理 | 62篇 |
综合类 | 554篇 |
基础理论 | 187篇 |
污染及防治 | 343篇 |
评价与监测 | 48篇 |
社会与环境 | 36篇 |
灾害及防治 | 27篇 |
出版年
2023年 | 10篇 |
2022年 | 57篇 |
2021年 | 33篇 |
2020年 | 23篇 |
2019年 | 24篇 |
2018年 | 28篇 |
2017年 | 55篇 |
2016年 | 45篇 |
2015年 | 42篇 |
2014年 | 76篇 |
2013年 | 107篇 |
2012年 | 97篇 |
2011年 | 75篇 |
2010年 | 56篇 |
2009年 | 68篇 |
2008年 | 87篇 |
2007年 | 58篇 |
2006年 | 72篇 |
2005年 | 27篇 |
2004年 | 24篇 |
2003年 | 29篇 |
2002年 | 29篇 |
2001年 | 23篇 |
2000年 | 25篇 |
1999年 | 33篇 |
1998年 | 26篇 |
1997年 | 23篇 |
1996年 | 18篇 |
1995年 | 25篇 |
1994年 | 11篇 |
1993年 | 16篇 |
1992年 | 18篇 |
1991年 | 10篇 |
1990年 | 6篇 |
1989年 | 3篇 |
1988年 | 5篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 4篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
排序方式: 共有1373条查询结果,搜索用时 750 毫秒
391.
392.
393.
394.
汽油无铅化与环境空气中铅污染的变化趋势 总被引:4,自引:0,他引:4
文章简要分析了 1 998年天津市环境空气及交通环境空气中铅污染的程度。机动车尾气排放是环境空气及交通环境空气中铅污染的重要来源 ,1 998年机动车推广使用无铅汽油后天津市铅污染状况明显减轻。 相似文献
395.
396.
397.
Swine manure is associated with emissions of odor, volatile organic compounds (VOCs) and other gases that can affect air quality on local and regional scales. In this research, a solid phase microextraction (SPME) and novel multidimensional gas chromatography-mass spectrometry-olfactometry (MDGC-MS-O) system were used to simultaneously identify VOCs and related odors emitted from swine manure. Gas samples were extracted from manure headspace using Carboxen/polydimethylsiloxane (PDMS) 85-microm SPME fibers. The MDGC-MS-O system was equipped with two columns in series with a system of valves allowing transfer of samples between columns (heartcutting). The heartcuts were used to maximize the isolation, separation, and identification of compounds. The odor impact of separated compounds was evaluated by a trained panelist for character and intensity. A total of 295 compounds with molecular weights ranging from 34 to 260 were identified. Seventy one compounds had a distinct odor. Nearly 68% of the compounds for which reaction rates with OH* radicals are known had an estimated atmospheric lifetime <24 h. 相似文献
398.
Effect of Rainfall Regime and Slope on Runoff in a Gullied Loess Region on the Loess Plateau in China 总被引:4,自引:0,他引:4
Runoff was measured from seven plots with different slopes nested in Tuanshangou catchment on the Loess Plateau to study effect of slopes on runoff in relation to rainfall regimes. Based on nine years of field observation and K-mean clusters, 84 rainfall events were grouped into three rainfall regimes. Rainfall regime A is the group of events with strong rainfall intensity, high frequency, and short duration. Rainfall regime C consists of events with low intensity, long duration, and infrequent occurrence. Rainfall regime B is the aggregation of events of medium intensity and medium duration, and less frequent occurrence. The following results were found: (1) Different from traditional studies, runoff coefficient neither decreased nor increased, but presented peak value on the slope surfaces; (2) For individual plot, runoff coefficients induced by rainfall regime A were the highest, and those induced by rainfall regime C were the lowest; Downslope, the runoff coefficients induced by three rainfall regimes presented the same changing trend, although the peak value induced by regime A occurred on a shorter slope length compared to those by regime B and C; (3) Scale effect on runoff induced by rainfall regime A was the least, and that induced by rainfall regime C was the largest. These results can be explained by the interactions of crusting, soil moisture content, slope length and gradient, and erosion units, etc., in the context of different rainfall regimes. 相似文献
399.
基础化学是环境类高职高专院校开设的一门重要的基础理论课程.针对我院基础化学教学中存在的教材、教学、实验、考核等方面的一些问题,从不同角度提出了改革措施,包括改革教学手段,编写适用教材,创新实验方法,更新考核方式等,希望对高职高专教学起到一些推动作用. 相似文献
400.