全文获取类型
收费全文 | 13914篇 |
免费 | 144篇 |
国内免费 | 113篇 |
专业分类
安全科学 | 429篇 |
废物处理 | 604篇 |
环保管理 | 2138篇 |
综合类 | 2693篇 |
基础理论 | 3154篇 |
环境理论 | 7篇 |
污染及防治 | 3566篇 |
评价与监测 | 839篇 |
社会与环境 | 667篇 |
灾害及防治 | 74篇 |
出版年
2022年 | 111篇 |
2021年 | 121篇 |
2020年 | 85篇 |
2019年 | 104篇 |
2018年 | 203篇 |
2017年 | 185篇 |
2016年 | 305篇 |
2015年 | 226篇 |
2014年 | 303篇 |
2013年 | 1098篇 |
2012年 | 402篇 |
2011年 | 570篇 |
2010年 | 454篇 |
2009年 | 518篇 |
2008年 | 555篇 |
2007年 | 619篇 |
2006年 | 542篇 |
2005年 | 430篇 |
2004年 | 463篇 |
2003年 | 462篇 |
2002年 | 415篇 |
2001年 | 478篇 |
2000年 | 349篇 |
1999年 | 244篇 |
1998年 | 150篇 |
1997年 | 158篇 |
1996年 | 151篇 |
1995年 | 200篇 |
1994年 | 184篇 |
1993年 | 161篇 |
1992年 | 154篇 |
1991年 | 175篇 |
1990年 | 151篇 |
1989年 | 148篇 |
1988年 | 159篇 |
1987年 | 135篇 |
1986年 | 118篇 |
1985年 | 120篇 |
1984年 | 154篇 |
1983年 | 152篇 |
1982年 | 153篇 |
1981年 | 122篇 |
1980年 | 109篇 |
1979年 | 125篇 |
1978年 | 99篇 |
1977年 | 93篇 |
1976年 | 87篇 |
1975年 | 96篇 |
1974年 | 108篇 |
1972年 | 77篇 |
排序方式: 共有10000条查询结果,搜索用时 140 毫秒
661.
James L. Lindgren Henry J. Krauss Marye Anne Fox 《Journal of the Air & Waste Management Association (1995)》2013,63(2):166-168
A demonstration of the GHEMFIX solidification/stabilization process was conducted under the United States Environmental Protection Agency’s (EPA) Superfund Innovative Technology Evaluation (SITE) program. The demonstration was conducted in March 1989, at the Portable Equipment Salvage Company (PESC) uncontrolled hazardous waste site in Clackamas, Oregon. Waste containing lead, copper, and polychlorinated biphenyls (PCBs) from four different areas of the site were treated. Results showed substantial reduction of leachable lead and copper between the untreated waste and treated waste utilizing the EPA Toxicity Characteristics Leaching Procedure (TCLP) test. The effectiveness of this process for immobilizing PCBs could not be determined since the raw waste did not leach PCBs at high concentrations, utilizing the TCLP test. Data from other leaching tests for lead and copper would need to be utilized as input into a site specific groundwater model to determine whether solidification/stabilization would be an acceptable remedy for the site. Physical testing results indicated durability in exposed conditions. 相似文献
662.
James McCarroll 《Journal of the Air & Waste Management Association (1995)》2013,63(6):652-656
The increased use of coal projected under the National Energy Plan has raised fears of increased morbidity and mortality related to fossil fuel combustion products. The evidence for adverse health effects from the major emissions of coal combustion is considered, as well as the basis for predictions of an increase in morbidity and mortality. It can be concluded that with presently available control technology, no detectable adverse health effects will be observed associated with increased coal combustion. It is further concluded that a reduction in energy supply, or a large increase in energy cost leading to reduced energy supply to lower socio-economic groups will cause far more demonstrable adverse health effects than increased coal utilization. 相似文献
663.
James H. Vincent 《Journal of the Air & Waste Management Association (1995)》2013,63(4):395-396
This paper describes a risk assessment methodology for preliminary assessment of municipal sludge incineration. The methodology is a valuable tool in that it can be used for determining the hazard indices of chemical contaminants that might be present in sewage sludge used in incineration. The paper examines source characteristics (i.e., facility design), atmospheric dispersion of emission, and resulting human exposure and risk from sludge incinerators. Seven of the ten organics were screened for furtherinvestigation. An example of the calculations are presented for cadmium. 相似文献
664.
665.
James E. Hardy John J. Knarr 《Journal of the Air & Waste Management Association (1995)》2013,63(4):376-379
This paper reports the development of a rapid, continuous technique for analyzing fixed nitrogen species (NH3, HCN, CH3NH2, etc.). The technique uses a platinum catalyst at low pressure in combination with a conventional chemiluminescent NO x analyzer. Previous workers observed that conventional stainless steel catalysts, and platinum catalysts operated at atmospheric pressure, do not reliably convert NH3 to NO. The most serious problem was the variation in the efficiency of these catalysts with operating conditions. Changes in temperature, gas composition, or XNH3 could change the conversion efficiency from 99.9% to <30%. The new conversion technique, however, is quantitative up to several thousand ppm NH3 in either O2/He or O2/CO2/N2. 相似文献
666.
667.
D. F. Adams S. O. Farwell M. R. Pack E. Robinson 《Journal of the Air & Waste Management Association (1995)》2013,63(10):1083-1089
Data are presented for the first systematic measurements of biogenic sulfur gas flux from the major soil orders within the eastern and southeastern United States. Sulfur flux samples were collected and analyzed on-site during the fall of 1977, spring and summer of 1978 and summer of 1979. A total of 27 sampling locales in 17 states were examined. Eight additional sites were visited in 1980. At some locales, two to four soils were examined, providing an even broader sampling of the soil orders. Three of the locales were revisited two or three times during the course of the study to establish the influence of seasonal climatology upon the measured emission rates and chemical composition of the sulfur flux mixtures. The sulfur gas enhancement of sulfur-free sweep air passing through dynamic emission flux chambers placed over selected sampling areas was determined by combined cryogenic enrichment sampling and wall-coated, open tubular, capillary column, cryogenic gas chromatography (WCOT/GC) using a sulfur selective, flame photometric detector (FPD). Sulfur gas mixtures varied with soil order, ambient temperature, insolation, soil moisture, cultivation, and vegetative cover. Statistical analyses indicated strong temperature and soil order relationships for sulfur emissions from soils. Fluxes ranged from 0.001 g to 1940 g of total sulfur as S/m2/yr. The calculated mean annual sulfur flux, weighted by soil order, was 0.03 g S/m2/yr for the study land area, or 110,872 metric tons (mT). The estimated annual average sulfur flux increased from 65 mT per 6400 km2 for the land grids in the northernmost east-west grid tier to an average 1800 mT for the land grids in the southern Florida grid tiers. This systematic sampling of major soils provides a much broader data base for estimating biogenic sulfur flux than previously reported for isolated intertidal sites, and presents the first sulfur flux estimates for inland soils which make up approximately 93% of the land of the eastern United States. 相似文献
668.
Douglas W. Dockery James H. Ware Benjamin G. Ferris Jr. Frank E. Speizer Nancy R. Cook Stanislaw M. Herman 《Journal of the Air & Waste Management Association (1995)》2013,63(9):937-942
Pulmonary function of approximately 200 school children in Steubenville, OH was measured before and immediately following air pollution alerts in the fall of 1978 and 1979. TSP concentrations exceeded the National Primary Ambient Air Quality 24 h standards in 1978. SO2 exceeded the standard in 1979. The children were then reexamined in three weekly visits following each alert. Estimated mean Forced Vital Capacity (FVC) was approximately 2% lower following each alert, although the lowest means were observed one to two weeks after the episodes. Forced Expired Volume in 0.75 sec (FEV0.75) did not change during the 1978 study, but was 4% lower immediately following the 1979 alert. The children were measured again in five weekly examinations in the spring and fall of 1980. Air pollution levels did not exceed the standards on either occasion. In the spring of 1980, estimated mean FVC and FEV0.75 showed a decline similar to that observed following the alerts in 1978 and 1979. In the fall of 1980, there were no significant differences in the estimated mean FVC or FEV0.75 between the examinations. A total of 335 children were tested in the four studies, including 194 who participated in more than one study. The evidence for each child from all the studies was combined in a regression analysis of pulmonary function on TSP and SO2 average concentrations in the previous 24 h. The distribution of the individual regression coefficients was centered significantly below zero, implying a decrease in pulmonary function with increasing TSP and SO2 concentrations. The magnitude of the median change was less than 1% of the mean FVC and FEV0.75 over the range of TSP and SO2 concentrations observed. 相似文献
669.
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
670.