全文获取类型
收费全文 | 31510篇 |
免费 | 306篇 |
国内免费 | 301篇 |
专业分类
安全科学 | 802篇 |
废物处理 | 1235篇 |
环保管理 | 3646篇 |
综合类 | 7178篇 |
基础理论 | 7475篇 |
环境理论 | 17篇 |
污染及防治 | 7702篇 |
评价与监测 | 2162篇 |
社会与环境 | 1701篇 |
灾害及防治 | 199篇 |
出版年
2022年 | 271篇 |
2021年 | 246篇 |
2020年 | 198篇 |
2019年 | 249篇 |
2018年 | 433篇 |
2017年 | 461篇 |
2016年 | 650篇 |
2015年 | 538篇 |
2014年 | 797篇 |
2013年 | 2420篇 |
2012年 | 964篇 |
2011年 | 1227篇 |
2010年 | 1012篇 |
2009年 | 1128篇 |
2008年 | 1225篇 |
2007年 | 1303篇 |
2006年 | 1169篇 |
2005年 | 1013篇 |
2004年 | 955篇 |
2003年 | 983篇 |
2002年 | 879篇 |
2001年 | 1124篇 |
2000年 | 806篇 |
1999年 | 524篇 |
1998年 | 372篇 |
1997年 | 367篇 |
1996年 | 376篇 |
1995年 | 419篇 |
1994年 | 406篇 |
1993年 | 340篇 |
1992年 | 372篇 |
1991年 | 368篇 |
1990年 | 376篇 |
1989年 | 317篇 |
1988年 | 313篇 |
1987年 | 230篇 |
1986年 | 268篇 |
1985年 | 300篇 |
1984年 | 285篇 |
1983年 | 269篇 |
1982年 | 279篇 |
1981年 | 273篇 |
1980年 | 243篇 |
1979年 | 252篇 |
1978年 | 212篇 |
1977年 | 206篇 |
1974年 | 205篇 |
1972年 | 192篇 |
1967年 | 205篇 |
1966年 | 181篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
111.
P. T. E. Ozoh 《Environmental monitoring and assessment》1992,21(1):1-10
Without sediment, increasing salinity (7.3 to 29.2) and increasing temperature (12 to 22 °C) reduced the toxicity of copper to juvenile Hediste diversicolor. The LC50 values ranged from 357 gL-1 in 7.3 to 513 g L-1 in 29.2 at 12°C and from 247 to 500 g L-1 at 22°C. In deionized water all the juvenile were dead in all solutions to which copper was added (100 to 600 g L-1). Dead worms were swollen and everted their pharynxs. In higher doses of copper (500 to 600 g L-1) the worms were abnormal in behaviour in all salinities (0 to 29.2). The ability to swim or crawl was disturbed.With sediments increasing temperature and increasing salinity increased the toxicity of copper to the worms. The LC50 values ranged from 3200 to 4100 g L-1 at 22°C. The response of the juvenile to copper was antagonistic to increasing temperature and salinity and synergistic to increasing salinity and increasing temperature without and with the sediment respectively. 相似文献
112.
This paper documents the rapid expansion and changes in food aid flows to Sub-Saharan Africa up to mid-1985. Trends for Sub-Saharan Africa as a whole and for the more seriously affected countries are examined, as are the comparative experiences of food aid of individual countries in the region. Table 11 lists the Sub-Saharan African countries and indicates the most seriously affected food-short countries, as defined by the WFP/FAO task force. It should be borne in mind that some practical problems exist in compiling data on food aid. These include lack of availability of reliable data, especially of most recent data; lack of common terminology and definitions; and different accounting systems. These data problems are sometimes a source of confusion. However, the basic facts are clear: food aid gradually emerged during the early 1980s as a resource too often of considerable significance to many countries of Sub-Saharan Africa. These trends were only accelerated with the crisis of 1984-1985. These facts provide a point of reference for further analysis of the sources of the crisis, its actual dimensions and consequences. 相似文献
113.
Riebsame WE 《Disasters》1985,9(4):295-300
Three recent cases of climate extremes are studied to identify human impacts and response strategies and to identify common characteristics that may help illuminate the nature of climate hazards. The 1980 heat wave in the central United States, 1981 cold wave in Boston, Massachusetts, and recent flooding and lake level rise in northern Utah, illustrate several important aspects of climate hazards that separate them from the more traditional set of catastrophic events (e.g. tornadoes, hurricanes and earthquakes) usually dealt with by hazards research and management. Among those characteristics are an emphasis on health impacts rather than physical damage, accumulative effects rather than short shocks, a tendency for impacts to accrue to certain socio-economic classes, and relatively slow onset. The management and research implications of these hazard characteristics are explored. 相似文献
114.
Andharia Jigar K. Haldar Sanjay Samaddar Shilpa Maiti Subarna 《Environment, Development and Sustainability》2022,24(9):11449-11469
Environment, Development and Sustainability - Drying of fish at the Sagar Island (21.7269° N, 88.1096° E) is generally carried out in open sun on the seashore on plastic sheets or mat of... 相似文献
115.
116.
117.
118.
119.
120.
Samari Mohammad Ridha Firas Manovic Vasilije Macchi Arturo Anthony E. J. 《Mitigation and Adaptation Strategies for Global Change》2020,25(1):25-41
Mitigation and Adaptation Strategies for Global Change - Direct air capture (DAC) is a developing technology for removing carbon dioxide (CO2) from the atmosphere or from low-CO2-containing... 相似文献