全文获取类型
收费全文 | 29502篇 |
免费 | 325篇 |
国内免费 | 222篇 |
专业分类
安全科学 | 832篇 |
废物处理 | 1061篇 |
环保管理 | 4037篇 |
综合类 | 4668篇 |
基础理论 | 8543篇 |
环境理论 | 21篇 |
污染及防治 | 7714篇 |
评价与监测 | 1742篇 |
社会与环境 | 1240篇 |
灾害及防治 | 191篇 |
出版年
2022年 | 179篇 |
2021年 | 180篇 |
2019年 | 214篇 |
2018年 | 389篇 |
2017年 | 379篇 |
2016年 | 556篇 |
2015年 | 491篇 |
2014年 | 679篇 |
2013年 | 2134篇 |
2012年 | 844篇 |
2011年 | 1251篇 |
2010年 | 1027篇 |
2009年 | 1034篇 |
2008年 | 1250篇 |
2007年 | 1331篇 |
2006年 | 1185篇 |
2005年 | 1004篇 |
2004年 | 1003篇 |
2003年 | 939篇 |
2002年 | 937篇 |
2001年 | 1239篇 |
2000年 | 863篇 |
1999年 | 548篇 |
1998年 | 427篇 |
1997年 | 435篇 |
1996年 | 442篇 |
1995年 | 485篇 |
1994年 | 438篇 |
1993年 | 395篇 |
1992年 | 414篇 |
1991年 | 373篇 |
1990年 | 376篇 |
1989年 | 411篇 |
1988年 | 347篇 |
1987年 | 300篇 |
1986年 | 276篇 |
1985年 | 305篇 |
1984年 | 286篇 |
1983年 | 321篇 |
1982年 | 322篇 |
1981年 | 271篇 |
1980年 | 243篇 |
1979年 | 269篇 |
1978年 | 229篇 |
1977年 | 195篇 |
1976年 | 200篇 |
1975年 | 192篇 |
1974年 | 172篇 |
1973年 | 171篇 |
1972年 | 198篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
861.
862.
863.
Graham J. Cleary 《Journal of the Air & Waste Management Association (1995)》2013,63(7):490-496
All but one of the Australian States now have legislation to control Air Pollution. These are similar in broad principle and rely upon the system of prior approval and the use of emission limits. At the present time Victoria is the only State with legislation providing for the recycling of crankcase vent gases on motor cars. Methods being used to control pollution and future outlook and needs are discussed. At least 65 per cent of the crude oil requirements should be met by indigenous low sulfur oil by 1975. This fact and the imminent supply of natural gas to the four major cities and to the centers of heavy industrial development should result in a marked reduction in sulfur dioxide concentrations. A major outstanding problem is the lack of air pollution considerations in planning at regional and local government levels. 相似文献
864.
J. B. Maynard W. N. Sanders 《Journal of the Air & Waste Management Association (1995)》2013,63(7):505-510
The quantitative data obtained with a capillary GLC method, which is used to determine the individual C3-C12 hydrocarbons in full-range motor gasolines, have been employed in a computer program to calculate the hydrocarbon composition of the vapor in equilibrium with a gasoline at 100°F, as well as the equilibrium vapor-pressure of the gasoline at that temperature. The method used for computation is similar to that previously described by McEwen, assuming the gasoline to behave as an ideal liquid. Also calculated is the potential atmospheric reactivity of this equilibrium vapor relative to that from other gasolines when specific reactivity weighting factors for the individual hydrocarbons are employed. Calculated total vapor-pressure data agree well with experimental Reid vapor-pressure data obtained for typical premium-grade gasolines. Definite differences were observed in the relative potential atmospheric reactivities calculated at 100°F for the equilibrium vapors from the test gasolines. 相似文献
865.
C. M. Peterson H. J. Paulus G. H. Foley 《Journal of the Air & Waste Management Association (1995)》2013,63(10):795-801
Instruments capable of measuring in situ numbers of particles within specific size ranges covering a particle-diameter spectrum of approximately 0.001 – 10 microns have been employed to continuously monitor the concentration and size-distribution of atmospheric aerosols. The monitoring site was a television tower located on the boundary between Minneapolis and St. Paul, Minnesota. Air samples were drawn from 70, 170, and 500 feet above ground level and analyzed with optical, electrical, and condensation particle counters to obtain a number-size distribution within the 0.001 – 10 micron size range. In addition to the measurement of particle number and size, several micrometeorological parameters were simultaneously monitored. Particle number-size distributions which were measured during periods of temperature inversion are reported 相似文献
866.
J. G. Wilson D. W. Miller 《Journal of the Air & Waste Management Association (1995)》2013,63(10):682-685
The application of a high-efficiency centrifugal type of separator to fluid bed catalytic cracking units is described in which most of the catalyst particles often lost to the atmosphere are concentrated into a small part of the stack gas (2%). A further separation can then be made on this small stream by an auxiliary separator which further concentrates the catalyst particle into 0.1% of the initia stream. Performance of the main and auxiliary separators are such as to reduce the loss of catalyst particles in the stack gas from 800 ppm to less than 60 ppm in a typical unit. Large amounts of power can be recovered by application of expander turbines to catalytic cracking plants employing this system of separation. 相似文献
867.
868.
869.
870.
J. E. Wesler 《Journal of the Air & Waste Management Association (1995)》2013,63(8):701-703
Surface transportation creates most of the noise pollution imposed on our communities today. Reduction of this noise impact requires effective preparation and enforcement of regulations to control noise sources, and methods and locations of operation. At the Federal level, such action has begun, within the limited authority available. Concurrently, research and development programs are demonstrating that means to satisfy noise control regulations are technically practical and economically reasonable. This paper provides a brief review of Federal regulatory areas and corresponding R&D activities pertinent to surface transportation noise abatement. 相似文献