全文获取类型
收费全文 | 21864篇 |
免费 | 264篇 |
国内免费 | 174篇 |
专业分类
安全科学 | 673篇 |
废物处理 | 807篇 |
环保管理 | 3068篇 |
综合类 | 5807篇 |
基础理论 | 4836篇 |
环境理论 | 10篇 |
污染及防治 | 5024篇 |
评价与监测 | 1175篇 |
社会与环境 | 787篇 |
灾害及防治 | 115篇 |
出版年
2022年 | 168篇 |
2019年 | 160篇 |
2018年 | 313篇 |
2017年 | 308篇 |
2016年 | 449篇 |
2015年 | 337篇 |
2014年 | 465篇 |
2013年 | 1537篇 |
2012年 | 587篇 |
2011年 | 796篇 |
2010年 | 686篇 |
2009年 | 776篇 |
2008年 | 817篇 |
2007年 | 839篇 |
2006年 | 733篇 |
2005年 | 647篇 |
2004年 | 670篇 |
2003年 | 594篇 |
2002年 | 569篇 |
2001年 | 703篇 |
2000年 | 500篇 |
1999年 | 347篇 |
1998年 | 276篇 |
1997年 | 249篇 |
1996年 | 251篇 |
1995年 | 304篇 |
1994年 | 317篇 |
1993年 | 272篇 |
1992年 | 278篇 |
1991年 | 269篇 |
1990年 | 287篇 |
1989年 | 261篇 |
1988年 | 209篇 |
1987年 | 220篇 |
1986年 | 216篇 |
1985年 | 217篇 |
1984年 | 237篇 |
1983年 | 222篇 |
1982年 | 241篇 |
1981年 | 247篇 |
1980年 | 198篇 |
1979年 | 197篇 |
1978年 | 175篇 |
1977年 | 154篇 |
1976年 | 149篇 |
1974年 | 151篇 |
1968年 | 157篇 |
1967年 | 184篇 |
1966年 | 154篇 |
1964年 | 152篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
491.
Summary. Workers of the amblyoponine species Mystrium rogeri employ trail communication during recruitment to food sources and new nest sites. The trail pheromone originates from a hitherto
unknown sternal gland located in the 7th abdominal sternite. The recruiting ant deposits the gland secretions by a special
gaster-dragging behavior. The recruitment behavior can be complemented by a rapid vertical body shaking performed by some
recruiting ants inside the nest. M. rogeri workers possess a large pygidial gland, the secretion of which elicits a repellent response in other ant species.
Received 25 May 1998; accepted 15 June 1998. 相似文献
492.
493.
494.
Hal B.H. Cooper William R. Kaiser Sulakah R. Gautam Jo Marby Dani Saleh 《Environment international》1979,2(3):117-125
The paper describes the results of a study of the impact of the National Energy on the trend towards increased utilization of coal and lignite in Texas with forecasts of increased coal and lignite utilization for the electric utility and industrial sectors. Environmental impacts of this increased coal and lignite use are projected in terms of increased air pollutant emissions and air quality impacts. Economic costs of compliance with alternative source emission regulations are also projected for the electric utility industry.Lignite consumption in Texas under the National Energy Plan is projected to increase from the present 13 million metric tons in 1976 to 57 million metric tons annually by 1985. Sub-bituminous coal consumption in Texas is projected to increase from 1 million metric per year in 1976 to 49 million metric tons per year in 1985. Bituminous coal consumption in Texas is expected to increase from less than one million metric tons per year in 1976 to about 3 million metric tons per year in 1985.Major increases in sulfur oxides emissions from coal and lignite combustion in Texas can be expected by 1985 of up to 1.5 × 109 kg per year without controls and 0.2 × 109 kg per year with controls. Increases in acid precipitation formation will result in north-east Texas from extensive lignite usage for electric power generation as a detriment to agriculture. The photochemical air pollution problem in the Houston area will probably worsen primarily because of increased nitrogen oxides and sulfur oxides emissions because of industrial coal combustion. Capital costs of air pollution controls in Texas for coal-fired utility boilers are estimated as up to U.S. $3.9 billion by 1985, with total operating costs of up to U.S. $1.2 billion per year. 相似文献
495.
496.
497.
498.
499.
500.