全文获取类型
收费全文 | 14865篇 |
免费 | 112篇 |
国内免费 | 160篇 |
专业分类
安全科学 | 406篇 |
废物处理 | 607篇 |
环保管理 | 1691篇 |
综合类 | 3346篇 |
基础理论 | 3459篇 |
环境理论 | 6篇 |
污染及防治 | 3647篇 |
评价与监测 | 1128篇 |
社会与环境 | 774篇 |
灾害及防治 | 73篇 |
出版年
2022年 | 130篇 |
2021年 | 118篇 |
2020年 | 90篇 |
2019年 | 105篇 |
2018年 | 210篇 |
2017年 | 212篇 |
2016年 | 321篇 |
2015年 | 237篇 |
2014年 | 420篇 |
2013年 | 1059篇 |
2012年 | 463篇 |
2011年 | 615篇 |
2010年 | 485篇 |
2009年 | 546篇 |
2008年 | 589篇 |
2007年 | 597篇 |
2006年 | 564篇 |
2005年 | 518篇 |
2004年 | 467篇 |
2003年 | 471篇 |
2002年 | 455篇 |
2001年 | 607篇 |
2000年 | 390篇 |
1999年 | 266篇 |
1998年 | 154篇 |
1997年 | 169篇 |
1996年 | 180篇 |
1995年 | 199篇 |
1994年 | 186篇 |
1993年 | 137篇 |
1992年 | 172篇 |
1991年 | 179篇 |
1990年 | 173篇 |
1989年 | 142篇 |
1988年 | 162篇 |
1987年 | 101篇 |
1986年 | 131篇 |
1985年 | 131篇 |
1984年 | 124篇 |
1983年 | 118篇 |
1982年 | 126篇 |
1981年 | 130篇 |
1980年 | 93篇 |
1979年 | 101篇 |
1978年 | 102篇 |
1976年 | 93篇 |
1974年 | 105篇 |
1972年 | 87篇 |
1967年 | 100篇 |
1964年 | 92篇 |
排序方式: 共有10000条查询结果,搜索用时 159 毫秒
761.
Laurel J. Staley Marta K. Richards George L. Huffman Robert A. Olexsey Barry Dellinger 《Journal of the Air & Waste Management Association (1995)》2013,63(3):321-331
Measurements conducted on full-scale hazardous waste incinerators have occasionally shown a relationship between carbon monoxide (CO) emissions and emissions of toxic organic compounds. In this study, four mixtures of chlorinated C1 and C2 hydrocarbons were diluted in commercial-grade heptane and burned in a water-cooled turbulent flame reactor (TFR) under two different excess air levels. No correlation between CO and organic emissions could be discerned. Reasons for this lack of observable correlations are discussed in terms of combustion and chemical reaction kinetic theory. 相似文献
762.
763.
The dispersion of hot plumes emitted from a smelter complex located In the Columbia River Valley, British Columbia, was evaluated under stable and neutral conditions during two mornings In spring. Spatial measurements of SO2 and temperature within the plume were obtained by immersion probing using fast response helicopter and automobile mounted Instrumentation. In addition, meteorological measurements of vertical wind and temperature profiles at, and downwind from, the smelter were obtained from minisonde balloon releases. With weak down-valley winds, it was found that the plume axis elevations were generally lower during both stable and neutral conditions than would be predicted by Briggs plume-rise formulae. In contrast, plume dispersion, although confined in the horizontal by the steep valley walls during both stability regimes, was significantly enhanced by exceptionally good lateral mixing, particularly close to the source. 相似文献
764.
Charles W. Lewis Robert K. Stevens Reinhold A. Rasmussen Carlos A. Cardelino Thomas E. Pierce 《Journal of the Air & Waste Management Association (1995)》2013,63(3):299-300
ABSTRACT Previously reported volatile organic compounds (VOC) radiocarbon (14C) measurements for 1992 summertime Atlanta, GA, have been compared with chromatographic data and emissions inventory predictions. The chromatographic approach that was used provided a more comprehensive VOC characterization than typically achieved, and the emissions inventory was research-grade level (date-, site-, and time-specific). The comparisons are in general agreement that biogenic emissions contribute only modestly (<10%) to the VOC content of the particular ambient samples that were collected and measured. The choices of sampling site (near city-center) and times (early morning and late evening) are major influences on the results, which consequently should not be regarded as representing the average VOC biogenic impact for the Atlanta area. 相似文献
765.
766.
G. B. Howe R. K. M. Jayanty A. V. Rao W. F. Gutknecht C. E. Decker D. J. von Lehmden 《Journal of the Air & Waste Management Association (1995)》2013,63(9):823-826
A repository of 38 gaseous organic compounds in compressed gas cylinders has been established by EPA. This repository was established to provide standards for source test performance audits, that is, quantitative quality assurance tests. Among these compounds are ten halogenated organic species, which are the focus of this paper. Stability studies of all ten compounds have been performed to determine the feasibility of using them as performance audit standards. Results indicate that all of the halocarbons tested are adequately stable to be used as reliable audit standards. Subsequent to completion of stability studies, four of the ten halocarbons were used in source test performance audits. Results are available at this time for two of the four compounds; the results show agreement within 10% of the concentrations previously established by Research Triangle Institute. 相似文献
767.
H. E. Jeffries K. G. Sexton 《Journal of the Air & Waste Management Association (1995)》2013,63(11):1087-1089
768.
Seshasayi Dharmavaram Philip K. Hopke 《Journal of the Air & Waste Management Association (1995)》2013,63(6):812-813
Abstract This study comprehensively characterizes hourly fine particulate matter (PM2.5) concentrations measured via a tapered element oscillating microbalance (TEOM), β-gauge, and nephelometer from four different monitoring sites in U.S. Environment Protection Agency (EPA) Region 5 (in U.S. states Illinois, Michigan, and Wisconsin) and compares them to the Federal Reference Method (FRM). Hourly characterization uses time series and autocorrelation. Hourly data are compared with FRM by averaging across 24-hr sampling periods and modeling against respective daily FRM concentrations. Modeling uses traditional two-variable linear least-squares regression as well as innovative nonlinear regression involving additional meteorological variables such as temperature and humidity. The TEOM shows a relationship with season and temperature, linear correlation as low as 0.7924 and nonlinear model correlation as high as 0.9370 when modeled with temperature. The β-gauge shows no relationship with season or meteorological variables. It exhibits a linear correlation as low as 0.8505 with the FRM and a nonlinear model correlation as high as 0.9339 when modeled with humidity. The nephelometer shows no relationship with season or temperature but a strong relationship with humidity is observed. A linear correlation as low as 0.3050 and a nonlinear model correlation as high as 0.9508 is observed when modeled with humidity. Nonlinear models have higher correlation than linear models applied to the same dataset. This correlation difference is not always substantial, which may introduce a tradeoff between simplicity of model and degree of statistical association. This project shows that continuous monitor technology produces valid PM2.5 characterization, with at least partial accounting for variations in concentration from gravimetric reference monitors once appropriate nonlinear adjustments are applied. Although only one regression technically meets new EPA National Ambient Air Quality Standards (NAAQS) Federal Equivalent Method (FEM) correlation coefficient criteria, several others are extremely close, showing optimistic potential for use of this nonlinear adjustment model in garnering EPA NAAQS FEM approval for continuous PM2.5 sampling methods. 相似文献
769.
R. K. M. Jayanty J. A. Sokash G. B. Howe R. G. Fuerst T. J. Logan M. R. Midgett 《Journal of the Air & Waste Management Association (1995)》2013,63(12):1342-1346
A simple, inexpensive, and accurate technique for evaluating or auditing the sampling, recovery, and analytical phases of EPA Source Reference Method 25 has been developed. The technique involves spiking a U-shaped stainless steel cartridge containing Tenax® with known quantities of selected organic compounds and thermally desorbing them at temperatures from 160°C to 180°C to generate organic vapors quantitatively. The major advantages of this technique are that no other measurement methods can be used to determine the generated organic concentrations in lieu of Method 25; and that the cartridge can easily be taken to the field for evaluation. The organic compounds generated in test runs are collected and analyzed using the Method 25 procedure. The generation of organics is quantitative and recoveries were found to be 100 ± 10%. The time required for desorption of the majority of organics is generally less than forty-five minutes at a flow rate of 100 mL/min; however, based on laboratory experience the recommended sampling time is sixty minutes. These spiked cartridges are stable at room temperature over a two-month period. Results of interlaboratory studies showed close agreement with the expected concentrations based on calculations from the mass loadings and sample volumes. 相似文献
770.
J.D. Hamilton K.H. Reinert J.V. Hagan W.V. Lord 《Journal of the Air & Waste Management Association (1995)》2013,63(4):247-251
Abstract Synthetic polymers reach municipal landfills as components of products such as waste household paints, packaging films, storage containers, carpet fibers, and absorbent sanitary products. Some polymers in consumer products that reach landfills are designed to photodegrade or biodegrade. This article examines the significance of degradable polymers in management of solid waste in municipal landfills. Most landfills are not designed to photodegrade or biodegrade solid waste. Landfill disposal of stable polymers such as polyacrylics and polyethylenes is not associated with significant polymer degradation or mobility. Stability to photodegradation and biodegradation is an advantage when municipal landfills are used for disposal of polymer products as solid waste. Use of landfill disposal can be a responsible means to manage polymer waste and can be part of an overall waste management plan which includes source reduction, recycling, reuse, composting, and waste-to-energy incineration. 相似文献