全文获取类型
收费全文 | 636篇 |
免费 | 13篇 |
国内免费 | 11篇 |
专业分类
安全科学 | 64篇 |
废物处理 | 17篇 |
环保管理 | 156篇 |
综合类 | 129篇 |
基础理论 | 150篇 |
污染及防治 | 91篇 |
评价与监测 | 31篇 |
社会与环境 | 18篇 |
灾害及防治 | 4篇 |
出版年
2023年 | 7篇 |
2022年 | 4篇 |
2021年 | 13篇 |
2020年 | 16篇 |
2019年 | 6篇 |
2018年 | 18篇 |
2017年 | 15篇 |
2016年 | 26篇 |
2015年 | 17篇 |
2014年 | 22篇 |
2013年 | 46篇 |
2012年 | 20篇 |
2011年 | 41篇 |
2010年 | 20篇 |
2009年 | 27篇 |
2008年 | 32篇 |
2007年 | 28篇 |
2006年 | 31篇 |
2005年 | 29篇 |
2004年 | 19篇 |
2003年 | 22篇 |
2002年 | 26篇 |
2001年 | 14篇 |
2000年 | 20篇 |
1999年 | 6篇 |
1998年 | 7篇 |
1997年 | 5篇 |
1996年 | 10篇 |
1995年 | 11篇 |
1994年 | 9篇 |
1993年 | 6篇 |
1992年 | 9篇 |
1991年 | 8篇 |
1990年 | 5篇 |
1988年 | 8篇 |
1987年 | 5篇 |
1986年 | 3篇 |
1985年 | 4篇 |
1984年 | 2篇 |
1983年 | 5篇 |
1982年 | 6篇 |
1981年 | 10篇 |
1980年 | 6篇 |
1979年 | 2篇 |
1977年 | 3篇 |
1974年 | 2篇 |
1973年 | 3篇 |
1970年 | 1篇 |
1962年 | 1篇 |
1956年 | 1篇 |
排序方式: 共有660条查询结果,搜索用时 859 毫秒
491.
Expert Perceptions of Approaches to Protecting Isolated Wetlands in the Northeastern United States
下载免费PDF全文
![点击此处可从《Journal of the American Water Resources Association》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Kristin Floress Mary Beth Kolozsvary Jean Mangun 《Journal of the American Water Resources Association》2017,53(5):1048-1061
In this article, we describe how protecting vernal pools was discussed by experts in the northeastern United States (U.S) within the context of a theoretical policy framework. We offer insight about characteristics of feasible vernal pool policy solutions, and identify gaps in our understanding, particularly regarding conditions in states currently lacking specific vernal pool protections. Vernal pools are geographically isolated, intermittent wetlands that provide important habitat for a variety of plants and animals. Many may not be federally protected as a result of judicial decisions over the past two decades, and the rule intended to clarify what qualifies for federal protection is currently being reviewed by the courts. Thus, state or local policy approaches may be alternatives to conserving vernal pools. We interviewed vernal pool experts in the northeastern U.S. regarding approaches to vernal pool protection and analyzed their perceptions through the lens of Kingdon's ( 2011 ) multiple streams policy development framework. The framework denotes 13 characteristics of three processes associated with policy development: problem identification, policy solution development, and the impacts of politics. While analyzed for all 13 components, we found participants most often discussed feasibility of policy formulation and implementation, particularly with regard to protecting vernal pools of high value while also remaining within the bounds of what public opinion supports. 相似文献
492.
Mary B. Ogundiran Tordue G. Buluku Joshua O. Babayemi Oladele Osibanjo 《Journal of Material Cycles and Waste Management》2017,19(1):163-171
Electrical electronics constitute a significant quantity of municipal solid wastes which are discarded after use in open dumpsites especially in the developing countries. The aim of this study was to characterise the material and chemical components, evaluate current management practices and investigate recovery of lead from battery electrodes (BEs) of waste rechargeable electric lamps (RLs). Twenty-six waste RLs of different models were sampled in Nigeria and characterised. Their BEs were analysed for Pb, Cr, Mn, Cu, Zn, Ni and Fe after acid digestion. Questionnaires were distributed to unselected respondents to assess usage and disposal of the lamps. Reaction of citric acid solutions with Pb in the presence of H2O2 was used for the recovery of Pb. 69 % of the respondents disposed their waste RLs in open dumpsites. The mean ± SD concentrations of Pb, Cr, Mn, Cu, Zn, Ni and Fe in the BEs were 600 ± 0.2 g/kg, 65.4 ± 40 mg/kg, 5.05 ± 4.0 mg/kg, 6.81 ± 5.0 mg/kg, 5.98 ± 3.0 mg/kg, 50.0 ± 30 mg/kg and 40.2 ± 35 mg/kg, respectively. The results show that the batteries are lead-acid batteries which require management. At the optimal conditions of S/L = 0.14, temperature = 20 °C and leaching time = 5 h, about 95 % Pb was recovered in form of lead citrate from the battery. High recovery of Pb is possible with simple and environment-friendly reactions. 相似文献
493.
Scenario‐Based and Scenario‐Neutral Assessment of Climate Change Impacts on Operational Performance of a Multipurpose Reservoir
下载免费PDF全文
![点击此处可从《Journal of the American Water Resources Association》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Allison G. Danner Mohammad Safeeq Gordon E. Grant Charlotte Wickham Desirée Tullos Mary V. Santelmann 《Journal of the American Water Resources Association》2017,53(6):1467-1482
Scenario‐based and scenario‐neutral impacts assessment approaches provide complementary information about how climate change‐driven effects on streamflow may change the operational performance of multipurpose dams. Examining a case study of Cougar Dam in Oregon, United States, we simulated current reservoir operations under scenarios of plausible future hydrology. Streamflow projections from the CGCM3.1 general circulation model for the A1B emission scenario were used to generate stochastic reservoir inflows that were then further perturbed to simulate a potentially drier future. These were then used to drive a simple reservoir model. In the scenario‐based analysis, we found reservoir operations are vulnerable to climate change. Increases in fall and winter inflow could lead to more frequent flood storage, reducing flexibility to store incoming flood flows. Uncertainty in spring inflow volume complicates projection of future filling performance. The reservoir may fill more or less often, depending on whether springs are wetter or drier. In the summer, drawdown may occur earlier to meet conservation objectives. From the scenario‐neutral analysis, we identified thresholds of streamflow magnitude that can predict climate change impacts for a wide range of scenarios. Our results highlight projected operational challenges for Cougar Dam and provide an example of how scenario‐based and scenario‐neutral approaches may be applied concurrently to assess climate change impacts. 相似文献
494.
495.
Harry Freeman Teresa Harten Johnny Springer Paul Randall Mary Ann Curran Kenneth Stone 《Journal of the Air & Waste Management Association (1995)》2013,63(5):618-656
Abstract Pyrolytic product distribution rates and pyrolysis behavior of tire-derived fuels (TDF) were investigated using thermogravimetric analyzer (TGA) techniques. A TGA was designed and built to investigate the behavior and products of pyrolysis of typical TDF specimens. The fundamental knowledge of TGA analysis and principal fuel analysis are applied in this study. Thermogravimetry of the degradation temperature of the TDF confirms the overall decomposition rate of the volatile products during the depolymerization reaction. The principal fuel analysis (proximate and ultimate analysis) of the pyrolytic char products show the correlation of volatilization into the gas and liquid phases and the existence of fixed carbon and other compounds that remain as a solid char. The kinetic parameters were calculated using least square with minimizing sum of error square technique. The results show that the average kinetic parameters of TDF are the activation energy, E = 1322 ± 244 kJ/mol, a pre-exponential constant of A = 2.06 ± 3.47 × 1010 min?1, and a reaction order n = 1.62 ± 0.31. The model-predicted rate equations agree with the experimental data. The overall TDF weight conversion represents the carbon weight conversion in the sample. 相似文献
496.
George R. Southworth Steve E. Lindberg Mary Anna Bogle Hong Zhang Todd Kuiken Jack Price 《Journal of the Air & Waste Management Association (1995)》2013,63(7):870-877
Abstract Waste distribution and compaction at the working face of municipal waste landfills releases mercury vapor (Hg0) to the atmosphere, as does the flaring of landfill gas. Waste storage and processing before its addition to the landfill also has the potential to release Hg0 to the air if it is initially present or formed by chemical reduction of HgII to Hg0 within collected waste. We measured the release of Hg vapor to the atmosphere during dumpster and transfer station activities and waste storage before landfilling at a municipal landfill operation in central Florida. We also quantified the potential contribution of specific Hg-bearing wastes, including mercury (Hg) thermometers and fluorescent bulbs, and searched for primary Hg sources in sorted wastes at three different landfills. Surprisingly large fluxes were estimated for Hg losses at transfer facilities (~100 mg/hr) and from dumpsters in the field (~30 mg/hr for 1,000 dumpsters), suggesting that Hg emissions occurring before landfilling may constitute a significant fraction of the total emission from the disposal/landfill cycle and a need for more measurements on these sources. Reducing conditions of landfill burial were obviously not needed to generate strong Hg0 signals, indicating that much of the Hg was already present in a metallic (Hg0) form. Attempts to identify specific Hg sources in excavated and sorted waste indicated few readily identifiable sources; because of effective mixing and diffusion of Hg0, the entire waste mass acts as a source. Broken fluorescent bulbs and thermometers in dumpsters emitted Hg0 at 10 to >100 μg/hr and continued to act as near constant sources for several days. 相似文献
497.
Sholtz RI McLaughlin KR Cirillo PM Petreas M Park JS Wolff MS Factor-Litvak P Eskenazi B Krigbaum N Cohn BA 《Environment international》2011,37(4):709-714
Conserving irreplaceable, archived serum samples may sometimes conflict with the objective of minimizing measurement error due to laboratory effects. We sought to determine whether we could successfully combine assay results for DDT-related compounds and polychlorinated biphenyls (PCBs) in serum from the same birth cohort obtained from different laboratories over time. Using the Child Health and Development Studies (CHDS) serum archive, we compared variability for assays of a quality control pool to variability for assays of subject serum. The quality control pool was created from native archived serum samples that were pooled, then aliquoted, blinded and inserted pair-wise into assay batches along with the subject serum for 5 studies using CHDS samples conducted over a 13year period by three different laboratories. We found that the variability between laboratory and over time within laboratory was small relative to inter-individual variability for p,p'-DDT (1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane), p,p'-DDE (1,1'-dichloro-2,2'-bis(p-chlorophenyl)ethylene) and o,p'-DDT (1,1,1-trichloro-2-(p-chlorophenyl)-2-(o-chlorophenyl)-ethane). Results were also consistent for most PCB congeners which were detectable in 85% or more of samples. Our results suggest that it is possible to combine assays for DDT and PCB congeners measured at positive levels as they are accumulated for cohort subjects without risking meaningful misclassification due to variation stemming from laboratory or time period. This has significant implications for future study costs, conservation of irreplaceable archived samples and for leveraging past investments for future research. For PCB congeners with very low levels, findings caution against pooling of assays without further exploration. 相似文献
498.
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
499.
500.
Andrzej Bytnerowicz Dan Cayan Philip Riggan Susan Schilling Philip Dawson Mary Tyree Lynn Wolden Robert Tissell Haiganoush Preisler 《Atmospheric environment (Oxford, England : 1994)》2010,44(5):678-687
Combustion emissions and strong Santa Ana winds had pronounced effects on patterns and levels of ambient ozone (O3) in southern California during the extensive wildland fires of October 2007. These changes are described in detail for a rural receptor site, the Santa Margarita Ecological Reserve, located among large fires in San Diego and Orange counties. In addition, O3 changes are also described for several other air quality monitoring sites in the general area of the fires. During the first phase of the fires, strong, dry and hot northeasterly Santa Ana winds brought into the area clean continental air masses, which resulted in minimal diurnal O3 fluctuations and a 72-h average concentration of 36.8 ppb. During the second phase of the fires, without Santa Ana winds present and air filled with smoke, daytime O3 concentrations steadily increased and reached 95.2 ppb while the lowest nighttime levels returned to ~0 ppb. During that period the 8-h daytime average O3 concentration reached 78.3 ppb, which exceeded the federal standard of 75 ppb. After six days of fires, O3 diurnal concentrations returned to pre-fire patterns and levels. 相似文献