全文获取类型
收费全文 | 2375篇 |
免费 | 48篇 |
国内免费 | 27篇 |
专业分类
安全科学 | 98篇 |
废物处理 | 95篇 |
环保管理 | 719篇 |
综合类 | 143篇 |
基础理论 | 530篇 |
环境理论 | 1篇 |
污染及防治 | 610篇 |
评价与监测 | 162篇 |
社会与环境 | 74篇 |
灾害及防治 | 18篇 |
出版年
2023年 | 14篇 |
2022年 | 24篇 |
2021年 | 22篇 |
2020年 | 25篇 |
2019年 | 25篇 |
2018年 | 32篇 |
2017年 | 34篇 |
2016年 | 48篇 |
2015年 | 39篇 |
2014年 | 41篇 |
2013年 | 308篇 |
2012年 | 76篇 |
2011年 | 96篇 |
2010年 | 93篇 |
2009年 | 64篇 |
2008年 | 103篇 |
2007年 | 104篇 |
2006年 | 116篇 |
2005年 | 98篇 |
2004年 | 64篇 |
2003年 | 93篇 |
2002年 | 84篇 |
2001年 | 28篇 |
2000年 | 38篇 |
1999年 | 27篇 |
1998年 | 44篇 |
1997年 | 34篇 |
1996年 | 34篇 |
1995年 | 32篇 |
1994年 | 30篇 |
1993年 | 23篇 |
1992年 | 29篇 |
1991年 | 26篇 |
1990年 | 26篇 |
1989年 | 23篇 |
1988年 | 28篇 |
1987年 | 20篇 |
1986年 | 24篇 |
1985年 | 29篇 |
1984年 | 43篇 |
1983年 | 33篇 |
1982年 | 37篇 |
1981年 | 37篇 |
1980年 | 26篇 |
1979年 | 42篇 |
1978年 | 30篇 |
1977年 | 22篇 |
1976年 | 19篇 |
1971年 | 11篇 |
1970年 | 9篇 |
排序方式: 共有2450条查询结果,搜索用时 62 毫秒
941.
Christopher E. Johnson William C. Malm Gerald Persha John V. Molenar James R. Hein 《Journal of the Air & Waste Management Association (1995)》2013,63(12):1261-1265
An automated scanning densitometer system developed to estimate visibility-related parameters from photographic slides was tested in comparison to similar teleradiometric measurements. Parameters such as target-sky contrast, visual range, atmospheric light extinction coefficient, and plume and layered contrast can be estimated using this system; however, only target-sky radiance ratios and standard visual ranges were compared. More than 1600 concurrent densitometer and teleradiometer data pairs from eight National Park Service air quality and visibility monitoring locations in the western United States were analyzed using the techniques of correlation, linear regression, average bias and difference calculation, and cumulative frequency distribution generation. Correlation coefficients were good, especially with middle-range camera vistas around 50 km distant. Regression slopes approached unity with intercepts near zero. Average bias introduced into the determination of radiance ratios from slides ranged from near zero to 6 percent, depending on target distance. Standard visual range data distributions compared favorably at the low end with some minor differences at the high end. 相似文献
942.
William H. Prokop Hinrich L. Bohn 《Journal of the Air & Waste Management Association (1995)》2013,63(12):1332-1338
Biofilter technology has been applied recently to treating rendering odors. Soil beds are one class of biofilter but as yet have not been used for this application. Although wet scrubbers have been a traditional method of odor control, their capital and operating costs are impacting more severely. Soil bed systems are less expensive to install and operate. A soil bed system was installed at a rendering plant in Arizona and has been in operation since September 1983. The soil bed treats 1100 m3/h (650 cfm) of cooker noncondensables with a surface area of 420 m2(4500 ft2). The pressure drop across the soil bed is 5 cm (2 in.) of water. Odor sensory testing with the MTRI forced-choice triangle dynamic olfactometer indicates an odor removal efficiency of 99.9 percent is obtained with the soil bed. Soil bed odor removal efficiency is equivalent to or superior than that for incineration or scrubbing of high intensity odors from the rendering process. Recent experience during this past winter indicates a soil bed is a viable method for operation in a northern climate with severe winter weather conditions. Also, monitoring of the leachate from a soil bed indicated no contamination. 相似文献
943.
944.
Sherry O. Farwell William H. Chatham Charles J. Barinaga 《Journal of the Air & Waste Management Association (1995)》2013,63(9):1052-1059
This sensitive, albeit precarious, method for measuring ppb-ppt (V/V) concentrations of H2S was examined for various sources of potential error within the procedure. Filter preparation, filter storage, filter extraction, fluorimetric reagent stabilities, matrix differences between standards and samples, and possible interferences from other sulfur-containing compounds were separately studied for their effects on the analytical performance of the method. The overall method showed no Interference from SO2, CS2, COS, CH3SH, CH3SCH3, and SO4 -2. To minimize bias and obtain a reliable estimate of precision, the method should be calibrated with H2S standards rather than liquid bisulfide standards. The measurement precision is a function of the quantity of H2S collected as Ag2S and/or AgSH on the impregnated filters. Because of the method’s linear dynamic range, sufficient air should be sampled to achieve filter loadings of 15 to 35 ng S/filter. A quality control method based on fluorescein mercuric acetate (FMA) is presented that ensures data quality while reducing the otherwise frequent need for fluori-metric calibration. 相似文献
945.
James H. Turner Andrew S. Viner Richard E. Jenkins William M. Vatavuk John D. McKenna 《Journal of the Air & Waste Management Association (1995)》2013,63(9):1105-1112
This is the second of a two-part article that reviews baghouse filtration theory, presents size estimating methods, and gives costing procedures for a variety of baghouse types and sizes. Part I of the article discussed theory and sizing; this part presents costing. Information is given for estimating total capital investment including separate costs for the bare baghouse (five types), bags, and, where needed, cages and Venturis. Factors are given for installation and for indirect costs. Direct and indirect annual costs are discussed. An example problem is given. The material in this article is taken primarily from the EAB Control Cost Manual. 相似文献
946.
Vishnu S. Katari William M. Vatavuk Albert H. Wehe 《Journal of the Air & Waste Management Association (1995)》2013,63(2):198-201
A review of incineration techniques for control of volatile organic compound emissions is presented in two consecutive issues o/JAPCA. Part I presented an overview of the process including fundamentals and design considerations. Both thermal and catalytic incinerators were considered. Part IIpresents capital and annual operating cost estimates for both thermal and catalytic incinerator systems based on information received from a number of equipment manufacturers. 相似文献
947.
William R. King 《Journal of the Air & Waste Management Association (1995)》2013,63(3):275-277
There are economic and regulatory incentives for considering alternatives to the direct land disposal of solvent-bearing hazardous waste streams (EPA Hazardous Waste Codes: F001, F002, F003, F004, and F005). These alternatives include recycle/reuse (including use as a fuel substitute), destruction of a stream's solvent component, and treatment prior to land disposal. This paper reviews these three waste management alternatives and discusses their applicability to solvent waste streams having various physical characteristics. Seven waste treatment techniques which may be used to handle solvent wastes are described: incineration, agitated thin-film evaporation, fractional distillation, steam stripping, wet oxidation, carbon adsorption, and activated sludge biological treatment. 相似文献
948.
William B. Petersen Rodney Allen 《Journal of the Air & Waste Management Association (1995)》2013,63(8):826-833
Carbon monoxide exposures to commuters were simulated in a 5-day study in Los Angeles County. Exposures were determined by measuring CO in three vehicles as they traveled typical commuter routes. The data collected during this study include measurements of vehicle speed and CO measurements in the interior and exterior of the three vehicles during the morning and evening peak traffic periods. In addition, hourly averaged CO measurements were taken from eight south coastal Air Quality Management District fixed-site monitoring stations and six California Department of Transportation vans in the proximity of the commuter routes. These data were used to investigate the relationship of CO exposures to meteorological parameters, fixed-site monitors, and traffic conditions. The average ratio of interior CO concentrations to exterior CO concentrations was 0.92. Concentrations inside and outside the vehicles remained about the same even when the vehicles were driven with vents closed and windows up. Smoking was not permitted in the vehicles during the study. The average ratio of the hour average CO concentrations in the vehicles to fixed-site measurements was 3.9. However, this ratio decreases with increasing ambient CO levels. Although CO levels in the vehicles frequently exceeded 40 ppm and sometimes exceeded 60 ppm, the hour average CO concentrations did not exceed 35 ppm. Slow moving congested traffic is associated with higher CO levels in the vehicles than a high volume of traffic moving at a steady speed. 相似文献
949.
950.
William D. Vernon Bert M. Wyman Richard V. Hubert Joseph R. Snyder 《Journal of the Air & Waste Management Association (1995)》2013,63(12):1280-1282
A manual method for measuring reduced sulfur compounds in kraft pulp mill and sulfur recovery plant emissions was evaluated. The method involves removing SO2 from the gas stream (if present) with a citric acid-potassium citrate buffer that passes reduced sulfur compounds; thermal oxidation of all reduced sulfur compounds to SO2; collection of the SO2 in H2O2; and a titrimetric analysis of the H2O2 for SO4 2?. A heated filter removes alkaline particulate matter that would produce a negative interference if absorbed by the buffer. When used at kraft pulp mills, the method agrees closely with Reference Method 16, provided that nonregulated reduced sulfur compounds, such as carbonyl sulfide, are not present in the emissions. At sulfur recovery plants, nonregulated reduced sulfur compounds, such as thiophene, are likely to be present in the emissions and will produce a positive bias in the results obtained with this method. The precision of the method ranges from 1 to 7 percent relative standard deviation. 相似文献