全文获取类型
收费全文 | 18716篇 |
免费 | 192篇 |
国内免费 | 224篇 |
专业分类
安全科学 | 553篇 |
废物处理 | 812篇 |
环保管理 | 2757篇 |
综合类 | 3611篇 |
基础理论 | 4328篇 |
环境理论 | 10篇 |
污染及防治 | 4615篇 |
评价与监测 | 1410篇 |
社会与环境 | 919篇 |
灾害及防治 | 117篇 |
出版年
2022年 | 145篇 |
2021年 | 151篇 |
2020年 | 104篇 |
2019年 | 156篇 |
2018年 | 259篇 |
2017年 | 283篇 |
2016年 | 404篇 |
2015年 | 327篇 |
2014年 | 492篇 |
2013年 | 1534篇 |
2012年 | 607篇 |
2011年 | 813篇 |
2010年 | 645篇 |
2009年 | 697篇 |
2008年 | 795篇 |
2007年 | 815篇 |
2006年 | 748篇 |
2005年 | 639篇 |
2004年 | 617篇 |
2003年 | 625篇 |
2002年 | 585篇 |
2001年 | 665篇 |
2000年 | 464篇 |
1999年 | 350篇 |
1998年 | 218篇 |
1997年 | 225篇 |
1996年 | 239篇 |
1995年 | 255篇 |
1994年 | 234篇 |
1993年 | 195篇 |
1992年 | 232篇 |
1991年 | 215篇 |
1990年 | 216篇 |
1989年 | 182篇 |
1988年 | 186篇 |
1987年 | 133篇 |
1986年 | 172篇 |
1985年 | 167篇 |
1984年 | 165篇 |
1983年 | 162篇 |
1982年 | 158篇 |
1981年 | 174篇 |
1980年 | 131篇 |
1979年 | 121篇 |
1978年 | 125篇 |
1977年 | 99篇 |
1976年 | 104篇 |
1974年 | 110篇 |
1971年 | 97篇 |
1967年 | 105篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
791.
A. David Rossin John J. Roberts 《Journal of the Air & Waste Management Association (1995)》2013,63(4):254-259
With respect to health effects and types of emission sources, carbon monoxide is different from SO2 and airborne participates. The effects of nontoxic CO levels are temporary and reversible. The primary sources are automobiles and trucks, and concentrations are often highly localized. Episode control strategies developed for other pollutants are not applicable for coping with CO episodes. 相似文献
792.
Joseph D. McCain John P. Gooch Wallace B. Smith 《Journal of the Air & Waste Management Association (1995)》2013,63(2):117-121
This paper presents results of source size distribution measurements over the size range from 0.1 μm to 5 μm for six classes of particulate sources and fractional efficiency measurements on five full scale electrostatic precipitators and one pilot scale precipitator. The precipitators all showed moderately high to high particulate collection efficiencies for particles having diameters larger than a few micrometers or smaller than a few hundredths of a micrometer and a minimum in collection efficiency for particles having diameters of a few tenths of a micrometer. 相似文献
793.
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
794.
Roger J. Cheng Volker A. Mohnen Thomas T. Shen Michael Current John B. Hudson 《Journal of the Air & Waste Management Association (1995)》2013,63(8):787-790
The emphasis on participate control from industrial processes has been shifted recently towards fine particulates, having diameters less than 3 microns. There exists an urgent need for more scientific information of fine particle characterization.1,2 Coal and oil fired power plants are among the largest anthropogenic point sources of particulate matter.3 Limited knowledge is available on particle size distribution and trace metal composition in power plant emissions.4-7 The morphological properties of particle emissions have been largely neglected. In this report we present some information on particle characteristics for an oil-fired and coal-fired power plant. 相似文献
795.
Joseph Greco Robert O. Ezzell John H. Lytle 《Journal of the Air & Waste Management Association (1995)》2013,63(9):877-880
The objective of this paper is to describe the Tennessee Valley Authority's efforts and plans in designing an operating and maintenance program that will ensure maximum performance of the electrostatic precipitators at our power generating stations. Detailed operating and maintenance manuals are being prepared for each plant for the use of plant personnel. These manuals include instructions on operation, maintenance, and testing of the precipitators. Instructions on internal and external equipment inspections to be performed during unit operation, emergency and scheduled outages, and problem diagnostic procedures are included to help the plant personnel solve problem areas. Performance curves are included in the manuals which show the effect of gas volume flow, gas temperature, gas resistivity, coal changes, and loss of transformer-rectifier sets on the precipitator performance. In addition, opacity monitors that record continuous opacity readings are being installed at all our plants to assist the plant in monitoring precipitator performance. Full-time operating and maintenance crews are being organized at the plants to monitor and maintain the precipitator and ash-removal systems. Also, a staff of technical personnel is being organized at the central office to provide technical advice and assistance in design, operation, and maintenance problems and liaison and coordination for all the plants concerning the precipitators. Periodic precipitator field inspections, performance and operating parameter optimization testing, and review of the equipment operating logs are made by the central office technical personnel. Recommendations and technical assistance are then furnished to the plant with regard to the precipitator overall performance and operating characteristics. 相似文献
796.
John S. Nader 《Journal of the Air & Waste Management Association (1995)》2013,63(10):1002-1005
This article is a summary report on a workshop, Measurement Technology and Characterization of Primary Sulfur Oxides Emission from Combustion Sources, sponsored by the EPA Environmental Sciences Research Laboratory at Research Triangle Park, NC, held in Southern Pines, NC. The objectives of the workshop were: to review and discuss current measurement methods and problem areas for sulfur oxides emission with attention focused on sulfuric acid, sulfates, and sulfur-bearing particulate matter; to review and discuss emission data from various combustion sources operating under different conditions, which include various pollutant controls, fuel composition, excess boiler oxygen, etc.; to delineate and recommend areas in need of research and development effort. Scientists were invited to present the results of their studies on primary sulfate emissions. The 3-day workshop devoted one day to measurement technology, a second to characterization, and a third to critical assessment of the presented papers and development of summary working group reports on each half-day session of the initial 2 days. Thirty-one papers were presented by 29 participants on measurements and characterization. Four working group reports were developed and summarized in the last day. Highlights of the papers and reports are briefly reviewed. Workshop proceedings are available as an EPA publication. 相似文献
797.
John A. Cooper 《Journal of the Air & Waste Management Association (1995)》2013,63(8):855-861
Currently available information suggests a substantial environmental impact from residential wood combustion emissions. Air pollution from this source is widespread and increasing. Current ambient measurements, surveys, and model predictions indicate winter respirable (<2 μm) emissions from residential wood combustion can easily exceed all other sources. Both the chemical potency and deliverability of the emissions from this source are of concern. The emissions are almost entirely in the inhalable size range and contain toxic and priority pollutants, carcinogens, co-carcinogens, cilia toxic, mucus coagulating agents, and other respiratory irritants such as phenols, aldehydes, etc. This source is contributing substantially to the nonattainment of current particulate, carbon monoxide, and hydrocarbon ambient air quality standards and will almost certainly have a significant impact on potential future standards such as inhalable particulates, visibility, and other chemically specific standards. Emission from this growing source is likely to require additional expenditures by industry for air pollution control equipment in nonattainment areas. 相似文献
798.
Walter John Georg Reischl 《Journal of the Air & Waste Management Association (1995)》2013,63(8):872-876
A cyclone with a 47 mm after-filter has been developed for ambient air size-selective monitoring. It has been extensively evaluated with laboratory-generated aerosol. Variation of the pressure drop and 50% cut point with flow rate show that the cyclone operates in a single flow regime with a vortex in the outlet flow. The particle size cutoff curve is comparable in sharpness to a cascade impactor and is the same for solid or liquid particles. At 21.7 L/min, D 50 is 2.5μm and at 15.4 L/min, D 50 is 3.5 μm. Collection efficiency data for flow rates from 8 to 27 L/min fit a universal curve when plotted vs. the normalized particle diameter, (D-D 50)/D 50 Reentrainment of previously deposited particles is less than 1 % of the loading per day. In field tests the cyclone has proved to be a very satisfactory size-selective sampler. 相似文献
799.
800.