全文获取类型
收费全文 | 689篇 |
免费 | 17篇 |
国内免费 | 12篇 |
专业分类
安全科学 | 26篇 |
废物处理 | 38篇 |
环保管理 | 157篇 |
综合类 | 68篇 |
基础理论 | 150篇 |
环境理论 | 3篇 |
污染及防治 | 178篇 |
评价与监测 | 59篇 |
社会与环境 | 29篇 |
灾害及防治 | 10篇 |
出版年
2023年 | 4篇 |
2022年 | 4篇 |
2021年 | 9篇 |
2020年 | 8篇 |
2019年 | 10篇 |
2018年 | 11篇 |
2017年 | 16篇 |
2016年 | 24篇 |
2015年 | 12篇 |
2014年 | 24篇 |
2013年 | 103篇 |
2012年 | 17篇 |
2011年 | 32篇 |
2010年 | 27篇 |
2009年 | 27篇 |
2008年 | 26篇 |
2007年 | 39篇 |
2006年 | 26篇 |
2005年 | 22篇 |
2004年 | 20篇 |
2003年 | 30篇 |
2002年 | 24篇 |
2001年 | 8篇 |
2000年 | 17篇 |
1999年 | 9篇 |
1998年 | 5篇 |
1997年 | 4篇 |
1996年 | 9篇 |
1995年 | 9篇 |
1994年 | 15篇 |
1993年 | 5篇 |
1992年 | 9篇 |
1991年 | 6篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1988年 | 6篇 |
1987年 | 6篇 |
1986年 | 5篇 |
1985年 | 7篇 |
1984年 | 12篇 |
1983年 | 5篇 |
1982年 | 7篇 |
1981年 | 10篇 |
1980年 | 7篇 |
1979年 | 5篇 |
1978年 | 5篇 |
1977年 | 4篇 |
1976年 | 3篇 |
1975年 | 4篇 |
1974年 | 3篇 |
排序方式: 共有718条查询结果,搜索用时 15 毫秒
551.
Gao H Miles MS Meyer BM Wong RL Overton EB 《Journal of environmental monitoring : JEM》2012,14(8):2164-2169
The purpose of this study was to evaluate the effects of cyclodextrin (CD) on the extraction of Macondo well oil from contaminated porous media over a range of hydroxypropyl-β-CD (HPβCD) concentrations. To our knowledge, this is the first dataset on this type of CD yet assembled for an actual crude oil. The results showed that HPβCD can significantly increase oil extraction efficiency, demonstrated by increasing concentrations of all tested normal alkanes (nC(15)-nC(35)) and polyaromatic hydrocarbons (PAHs) in the aqueous phase with increasing CD concentration. A linear relationship between the extraction enhancement effect and CD concentration were verified experimentally and high correlation coefficients for total PAHs (R(2) = 0.82) and alkanes (R(2) = 0.99) were determined. For a 20% CD solution, 3.13 wt% of alkanes and 32.12 wt% of total PAHs were extracted to the aqueous phase, which was significantly more than what was extracted with water only (0.04% and 0.21% for alkanes and PAHs, respectively). This result shows that the remediation of oil contaminated media can be significantly enhanced through the use of HPβCD solutions in flushing or pump and treat operations to remove sorbed oil. The CD extraction enhancement effect decreases with increasing n-alkane chain length for the carbon number range tested. CD significantly enhanced PAH extraction from sand and the enhancement effect increased in the order of parent compounds < C-1 substituted < C-2 substituted < C-3 substituted for most PAHs tested. This study provides important information to assess the feasibility of using CD as a near-shore agent to enhance the cleanup of oil contaminated porous media. 相似文献
552.
Christina L. M. Hargiss Edward S. DeKeyser 《Environmental monitoring and assessment》2014,186(2):979-985
Accessing research sites is an integral part of a research in the world today. Researching sites on privately owned lands creates unique challenges when compared to conducting research on government or publicly owned land. This study explores different methods for obtaining landowner information, permission to sample privately owned sites, and assesses the time it takes to obtain permission for randomly selected study sites. During the study, researchers contacted 390 landowners to obtain permission to sample wetlands on privately owned lands. A variety of methods were used to contact landowners and determine which methods were most effective for obtaining permission. Methods included face-to-face discussion, phone calls, and mailed response letters. It took approximately 9 months to obtain landowner information, contact landowners, and obtain permission to sample sites. The most effective method for obtaining permission to sample sites was through face-to-face discussions with landowners. Overall, it took a longer period of time to obtain permission for the survey than it did to sample sites. Information from this study can be used by anyone conducting research on private land to better estimate the time it will take to obtain permission to sample sites and to estimate the most effective way to obtain permission based on project finances and available personnel. 相似文献
553.
Jennifer McGowan Rob Weary Leah Carriere Edward T. Game Joanna L. Smith Melissa Garvey Hugh P. Possingham 《Conservation biology》2020,34(5):1065-1075
Incentivized debt conversion is a financing mechanism that can assist countries with a heavy debt burden to bolster their long-term domestic investment in nature conservation. The Nature Conservancy, an international conservation-based nongovernmental organization, is adapting debt conversions to support marine conservation efforts by small island developing states and coastal countries. Prioritizing debt conversion opportunities according to their potential return on investment can increase the impact and effectiveness of this finance mechanism. We developed guidance on how to do so with a decision-support approach that relies on a novel threat-based adaptation of cost-effectiveness analysis. We constructed scenarios by varying parameters of the approach, including enabling conditions, expected benefits, and threat classifications. Incorporating both abatable and unabatable threats affected priorities across planning scenarios. Similarly, differences in scenario construction resulted in unique solution sets for top priorities. We show how environmental organizations, private entities, and investment banks can adopt structured prioritization frameworks for making decisions about conservation finance investments, such as debt conversions. Our guidance can accommodate a suite of social, ecological, and economic considerations, making the approach broadly applicable to other conservation finance mechanisms or investment strategies that seek to establish a transparent process for return-on-investment decision-making. 相似文献
554.
Alya Limayem Robert Scott Donofrio Chao Zhang Edward Haller Michael G. Johnson 《Journal of environmental science and health. Part. B》2013,48(11):827-832
The multidrug resistant Enterococcus faecium (MEF) strains originating from farm animals are proliferating at a substantial pace to impact downstream food chains and could reach hospitals. This study was conducted to elucidate the drug susceptibility profile of MEF strains collected from poultry products in Ann Arbor, MI area and clinical settings from Michigan State Lab and Moffitt Cancer Center (MCC) in Florida. Presumptive positive Enterococcus isolates at species level were identified by Matrix Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) analysis. The antibiotic susceptibility profile for both poultry and clinical strains was determined by the Thermo Scientific's Sensititre conform to the National Committee for Clinical Laboratory Standards (NCCLS) and validated via quantitative real-time PCR (qPCR) methods. Out of 50 poultry samples (Turkey: n = 30; Chicken: n = 20), 36 samples were positive for Enterococcus species from which 20.83% were identified as E. faecium. All the E. faecium isolates were multidrug resistant and displayed resistance to the last alternative drug, quinupristin/dalfopristin (QD) used to treat vancomycin resistant E. faecium (VRE) in hospitals. Results indicate the presence of MEF strains in food animals and clinical settings that are also resistant to QD. 相似文献
555.
556.
Edward B. Dismukes 《Journal of the Air & Waste Management Association (1995)》2013,63(2):152-156
This paper presents the results of an investigation of the conditioning of fly ash with ammonia in electrostatic pre-cipitators of power plants operated by the Tennessee Valley Authority. It focuses attention primarily on the mechanisms of conditioning encountered under the particular circumstances available for study. No effect of ammonia on the electrical resistivity of fly ash was evident. Instead, the effect of ammonia appeared to be an enhancement pf the space-charge component of the electric field used for charging and precipitating particles of fly ash. In addition, a second effect appeared to be an increase in the cohesiveness of precipitated ash and a reduction in the quantity of ash reentrained during electrode rapping. Data demonstrating the value of ammonia conditioning for lowering the emission pf fly ash during three precipitator studies are presented. Reasons for the ineffectiveness of ammonia conditioning during a fourth precipitator study are discussed. In conclusion, comments are made about the effects to be expected from ammonia conditioning under circumr stances different from those investigated experimentally, particularly with ammonia as a conditioning agent for fly ash from low sulfur western coal. 相似文献
557.
Economic projections and the growing experience with more diverse baghouse applications indicate that fabric filtration will become an even more popular type of control technology. While the fabric filter market shows signs of great promise now, an especially significant upturn is predicted within the next half dozen years when dry scrubbing becomes the primary process for combined S02 and par-ticulate control. In the interim, with more and more utility and industrial boilers gaining experience with baghouses, this control method can be expected to develop as an even more acceptable technique, especially on low S coal burning units. Nevertheless, the users stress the need for conservative planning and designing, giving extra care to start-up and maintenance procedures. 相似文献
558.
Edward H. Pechan James H. Wilson Jr. 《Journal of the Air & Waste Management Association (1995)》2013,63(10):1075-1078
Estimates of 1973–1982 annual SO2 emissions from electric utility plants are presented in this paper. Results are based on analyses of plant level data collected by the U.S. Department of Energy on consumption and quality of fuels burned. Emissions are estimated from known information about fuel consumption, sulfur content, ash content, and control equipment. Results show that electric utility emissions decreased 16% from 1973 to 1982 and that these reductions were due to the use of lower sulfur coals and to the operation of flue gas desulfurization equipment. 相似文献
559.
Robert S. Wright Edward L. Tew Clifford E. Decker Darryl J. von Lehmden William F. Barnard 《Journal of the Air & Waste Management Association (1995)》2013,63(4):384-385
Air pollution abatement policies must be based on quantitative information on current and future emissions of pollutants. As emission projections uncertainties are inevitable and traditional statistical treatments of uncertainty are highly time/resources consuming, a simplified methodology for nonstatistical uncertainty estimation based on sensitivity analysis is presented in this work. The methodology was applied to the “with measures” scenario for Spain, concretely over the 12 highest emitting sectors regarding greenhouse gas and air pollutants emissions. Examples of methodology application for two important sectors (power plants, and agriculture and livestock) are shown and explained in depth. Uncertainty bands were obtained up to 2020 by modifying the driving factors of the 12 selected sectors and the methodology was tested against a recomputed emission trend in a low economic-growth perspective and official figures for 2010, showing a very good performance.Implications:?A solid understanding and quantification of uncertainties related to atmospheric emission inventories and projections provide useful information for policy negotiations. However, as many of those uncertainties are irreducible, there is an interest on how they could be managed in order to derive robust policy conclusions. Taking this into account, a method developed to use sensitivity analysis as a source of information to derive nonstatistical uncertainty bands for emission projections is presented and applied to Spain. This method simplifies uncertainty assessment and allows other countries to take advantage of their sensitivity analyses. 相似文献
560.
Mary E. McLearn Michael J. Miller Paul T. Kostecki Edward J. Calabrese Lynne M. Preslo Wendell Suyama 《Journal of the Air & Waste Management Association (1995)》2013,63(4):428-435
Remedial options for leaking underground storage tanks were investigated in a joint project of the Electric Power Research Institute and the Underground Storage Tank Committee of the Utility Solid Waste Activities Group. Both existing and emerging technologies were examined. Thirteen remedial techniques were identified and initially characterized as in situ or non-in situ. In situ methods include volatilization, biodegradation, leaching and chemical reaction, vitrification, passive remediation, and isolation or containment. Non-in situ techniques include land treatment, thermal treatment, asphalt incorporation, solidification and stabilization, groundwater extraction and treatment, chemical extraction, and excavation. Soil and groundwater remediation problems have many site-specific considerations which must be considered in choosing an appropriate remedial option; these include cleanup goals, site and contaminant characteristics, cost, exposure pathways, and others. Appropriate remedial techniques are chosen by assessing technical, implementational, environmental and economic considerations of each available option to achieve the desired cleanup goal at the specified site. 相似文献