全文获取类型
收费全文 | 14029篇 |
免费 | 170篇 |
国内免费 | 119篇 |
专业分类
安全科学 | 425篇 |
废物处理 | 378篇 |
环保管理 | 2212篇 |
综合类 | 3339篇 |
基础理论 | 3373篇 |
环境理论 | 9篇 |
污染及防治 | 3462篇 |
评价与监测 | 649篇 |
社会与环境 | 401篇 |
灾害及防治 | 70篇 |
出版年
2018年 | 146篇 |
2017年 | 156篇 |
2016年 | 220篇 |
2015年 | 180篇 |
2014年 | 231篇 |
2013年 | 1023篇 |
2012年 | 351篇 |
2011年 | 500篇 |
2010年 | 347篇 |
2009年 | 443篇 |
2008年 | 499篇 |
2007年 | 535篇 |
2006年 | 487篇 |
2005年 | 363篇 |
2004年 | 381篇 |
2003年 | 424篇 |
2002年 | 352篇 |
2001年 | 485篇 |
2000年 | 332篇 |
1999年 | 235篇 |
1998年 | 167篇 |
1997年 | 158篇 |
1996年 | 194篇 |
1995年 | 197篇 |
1994年 | 214篇 |
1993年 | 192篇 |
1992年 | 192篇 |
1991年 | 189篇 |
1990年 | 215篇 |
1989年 | 200篇 |
1988年 | 171篇 |
1987年 | 167篇 |
1986年 | 149篇 |
1985年 | 168篇 |
1984年 | 155篇 |
1983年 | 163篇 |
1982年 | 166篇 |
1981年 | 167篇 |
1980年 | 150篇 |
1979年 | 148篇 |
1978年 | 145篇 |
1977年 | 129篇 |
1976年 | 137篇 |
1975年 | 114篇 |
1974年 | 144篇 |
1973年 | 125篇 |
1972年 | 126篇 |
1971年 | 105篇 |
1970年 | 106篇 |
1967年 | 116篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
J.M. Hoff P.V. Borgoul G. Tuncel J.M. Ondov W.R. Kelly L.T. Chen 《Journal of the Air & Waste Management Association (1995)》2013,63(8):721-728
ABSTRACT A stable rare-earth isotopic tracer was used to measure the deposition of KNO3 particles on soybean leaves by direct measurement of the tracer on the plant surfaces by thermal-ionization mass spectrometry. Submicrometer particles, made from a solution containing 3 |mg mL-1 neodymium isotope (148Nd, 87.9%) and 1,000 mg mL-1 KNO3, were dispersed with a two-fluid nozzle and released upwind of a soybean field. Total suspended- and size-fractionated-aerosol particles were collected on an open-face filter and in a micro-orifice impactor, respectively, at a distance of 40 m from the release point. Soybean leaves exposed to the plume were collected at distances ranging from 25 to 100 m. As little as 5.5 pg of the tracer (i.e., excess 148Nd) was detected in soybean leaves at signal-to-noise ratios ranging from 7,500 to 240,000, in the presence of 200 to 2,700 pg of naturally occurring Nd. The dry-particle deposition velocity, determined from the ratio of the aerial concentration and directly deposited aerosol (geometric mass mean diameter, 0.20 mm) flux, and its corresponding analytical uncertainty were 0.30 cm sec-1 and 2.5%, respectively. 相似文献
992.
Lane W. Kirkpatrick Warner K. Reeser Jr. 《Journal of the Air & Waste Management Association (1995)》2013,63(10):992-994
Of all the recreational activities in Colorado, skiing most greatly creates population densities such as to cause noticeable basinwide air pollution. Skiing is big business in this State as skiers spend over $127 million/year at ski resorts. Skiing provides pleasure to thousands of people. Many realize the importance of clear and clean air to the continuing happiness of skiers and to the success of recreational communities. 相似文献
993.
Both planning and design of integrated municipal solid waste management systems require accurate prediction of waste generation. This research predicted the quantity and distribution of biodegradable municipal waste (BMW) generation within a diverse ‘landscape’ of residential areas, as well as from a variety of commercial establishments (restaurants, hotels, hospitals, etc.) in the Dublin (Ireland) region. Socio-economic variables, housing types, and the sizes and main activities of commercial establishments were hypothesized as the key determinants contributing to the spatial variability of BMW generation. A geographical information system (GIS) ‘model’ of BMW generation was created using ArcMap, a component of ArcGIS 9. Statistical data including socio-economic status and household size were mapped on an electoral district basis. Historical research and data from scientific literature were used to assign BMW generation rates to residential and commercial establishments. These predictions were combined to give overall BMW estimates for the region, which can aid waste planning and policy decisions. This technique will also aid the design of future waste management strategies, leading to policy and practice alterations as a function of demographic changes and development. The household prediction technique gave a more accurate overall estimate of household waste generation than did the social class technique. Both techniques produced estimates that differed from the reported local authority data; however, given that local authority reported figures for the region are below the national average, with some of the waste generated from apartment complexes being reported as commercial waste, predictions arising from this research are believed to be closer to actual waste generation than a comparison to reported data would suggest. By changing the input data, this estimation tool can be adapted for use in other locations. Although focusing on waste in the Dublin region, this method of waste prediction can have significant potential benefits if a universal method can be found to apply it effectively. 相似文献
994.
995.
Lisa G. Shaffer Justine Coppinger S. Annie Morton Sarah Alliman Jessica Burleson Ryan Traylor Cathryn Walker Steve Byerly Allen N. Lamb Roger Schultz J. Britt Ravnan Catherine D. Kashork Beth S. Torchia Scott Sulpizio Kyle Sundin Mack Schermer Karl Adler Stephanie Dallaire Blake C. Ballif 《黑龙江环境通报》2011,31(8):778-787
996.
997.
998.
999.
1000.