全文获取类型
收费全文 | 11825篇 |
免费 | 97篇 |
国内免费 | 86篇 |
专业分类
安全科学 | 314篇 |
废物处理 | 547篇 |
环保管理 | 1512篇 |
综合类 | 2538篇 |
基础理论 | 2659篇 |
环境理论 | 6篇 |
污染及防治 | 3072篇 |
评价与监测 | 709篇 |
社会与环境 | 584篇 |
灾害及防治 | 67篇 |
出版年
2022年 | 101篇 |
2021年 | 105篇 |
2019年 | 81篇 |
2018年 | 166篇 |
2017年 | 147篇 |
2016年 | 243篇 |
2015年 | 191篇 |
2014年 | 261篇 |
2013年 | 867篇 |
2012年 | 331篇 |
2011年 | 464篇 |
2010年 | 357篇 |
2009年 | 415篇 |
2008年 | 449篇 |
2007年 | 519篇 |
2006年 | 459篇 |
2005年 | 373篇 |
2004年 | 380篇 |
2003年 | 387篇 |
2002年 | 349篇 |
2001年 | 440篇 |
2000年 | 315篇 |
1999年 | 208篇 |
1998年 | 116篇 |
1997年 | 131篇 |
1996年 | 116篇 |
1995年 | 164篇 |
1994年 | 163篇 |
1993年 | 131篇 |
1992年 | 136篇 |
1991年 | 157篇 |
1990年 | 120篇 |
1989年 | 127篇 |
1988年 | 135篇 |
1987年 | 115篇 |
1986年 | 84篇 |
1985年 | 100篇 |
1984年 | 125篇 |
1983年 | 127篇 |
1982年 | 123篇 |
1981年 | 97篇 |
1980年 | 94篇 |
1979年 | 106篇 |
1978年 | 89篇 |
1977年 | 85篇 |
1976年 | 78篇 |
1975年 | 90篇 |
1974年 | 101篇 |
1972年 | 69篇 |
1965年 | 74篇 |
排序方式: 共有10000条查询结果,搜索用时 538 毫秒
691.
J.F. Karlik A.J. Downer 《Journal of the Air & Waste Management Association (1995)》2013,63(11):1361-1367
ABSTRACT Five different models of dosimeters were compared in the Chernobyl Inner Exclusion Zone by measuring gamma radiation in 12 locations. We used an instrument made by Mirion Technologies, Inc., as the reference, since that instrument had an NIST-traceable calibration. Two models of dosimeters gave radiation values similar to the Mirion at all levels of radiation encountered. Two other models gave similar values to the Mirion instrument at low radiation levels but not at higher radiation levels encountered. These results offer a caution regarding the accuracy of inexpensive commercially available radiation instruments. Implications: Comparison of gamma ray dosimeters in the Chernobyl Exclusion Zone showed varying agreement with an NIST-calibrated instrument, as well as varying linearity of response to ambient radiation. These results suggest caution regarding accuracy of inexpensive dosimeters. However, dosimeters used that were manufactured in Ukraine exhibited good agreement with the reference instrument. 相似文献
692.
Dan Venables Nick F. Pidgeon Karen A. Parkhill Karen L. Henwood Peter Simmons 《Journal of environmental psychology》2012
Previous research notes that sense of place may intensify, and that levels of public risk perception may decrease with proximity to an established hazardous or stigmatised site. In addition, the literature suggests that sense of place may act either to mediate or moderate community perceptions of risk in such localities. This study comprised a major household survey (n = 1326) and an interview study (n = 39) and was conducted close to the nuclear power stations at Oldbury and Hinkley Point, both in the UK. It investigated the roles of perceptions of place and hazard proximity in considering (a) perceptions of risk and (b) public attitudes towards the building of a new nuclear power station in the nearby area. In addition, a novel scale was developed to measure the perceived contribution of the nearby nuclear power station to sense of place. The results suggest first, that sense of place mediates (but does not moderate) perceptions of risk in very proximate communities, and second, that public attitudes to new build in communities situated very close to established nuclear sites may be largely dependent on the extent to which the existing facility is perceived to contribute towards sense of place. The implications of these results for existing theory are discussed. 相似文献
693.
Predicted increases in coral disease outbreaks associated with climate change have implications for coral reef ecosystems
and the people and industries that depend on them. It is critical that coral reef managers understand these implications and
have the ability to assess and reduce risk, detect and contain outbreaks, and monitor and minimise impacts. Here, we present
a coral disease response framework that has four core components: (1) an early warning system, (2) a tiered impact assessment
program, (3) scaled management actions and (4) a communication plan. The early warning system combines predictive tools that
monitor the risk of outbreaks of temperature-dependent coral diseases with in situ observations provided by a network of observers
who regularly report on coral health and reef state. Verified reports of an increase in disease prevalence trigger a tiered
response of more detailed impact assessment, targeted research and/or management actions. The response is scaled to the risk
posed by the outbreak, which is a function of the severity and spatial extent of the impacts. We review potential management
actions to mitigate coral disease impacts and facilitate recovery, considering emerging strategies unique to coral disease
and more established strategies to support reef resilience. We also describe approaches to communicating about coral disease
outbreaks that will address common misperceptions and raise awareness of the coral disease threat. By adopting this framework,
managers and researchers can establish a community of practice and can develop response plans for the management of coral
disease outbreaks based on local needs. The collaborations between managers and researchers we suggest will enable adaptive
management of disease impacts following evaluating the cost-effectiveness of emerging response actions and incrementally improving
our understanding of outbreak causation. 相似文献
694.
Coastal and freshwater eutrophication continues to accelerate at sites around the world despite intense efforts to control agricultural P loss using traditional conservation and nutrient management strategies. To achieve required reductions in nonpoint P over the next decade, new tools will be needed to address P transfers from soils and applied P sources. Innovative remediation practices are being developed to remove nonpoint P sources from surface water and groundwater using P sorbing materials (PSMs) derived from natural, synthetic, and industrial sources. A wide array of technologies has been conceived, ranging from amendments that immobilize P in soils and manures to filters that remove P from agricultural drainage waters. This collection of papers summarizes theoretical modeling, laboratory, field, and economic assessments of P removal technologies. Modeling and laboratory studies demonstrate the importance of evaluating P removal technologies under controlled conditions before field deployment, and field studies highlight several challenges to P removal that may be unanticipated in the laboratory, including limited P retention by filters during storms, as well as clogging of filters due to sedimentation. Despite the potential of P removal technologies to improve water quality, gaps in our knowledge remain, and additional studies are needed to characterize the long-term performance of these technologies, as well as to more fully understand their costs and benefits in the context of whole-farm- and watershed-scale P management. 相似文献
695.
Ian R. Waite Jonathan G. Kennen Jason T. May Larry R. Brown Thomas F. Cuffney Kimberly A. Jones James L. Orlando 《Journal of the American Water Resources Association》2012,48(3):570-583
Waite, Ian R., Jonathan G. Kennen, Jason T. May, Larry R. Brown, Thomas F. Cuffney, Kimberly A. Jones, and James L. Orlando, 2012. Comparison of Stream Invertebrate Response Models for Bioassessment Metrics. Journal of the American Water Resources Association (JAWRA) 48(3): 570-583. DOI: 10.1111/j.1752-1688.2011.00632.x Abstract: We aggregated invertebrate data from various sources to assemble data for modeling in two ecoregions in Oregon and one in California. Our goal was to compare the performance of models developed using multiple linear regression (MLR) techniques with models developed using three relatively new techniques: classification and regression trees (CART), random forest (RF), and boosted regression trees (BRT). We used tolerance of taxa based on richness (RICHTOL) and ratio of observed to expected taxa (O/E) as response variables and land use/land cover as explanatory variables. Responses were generally linear; therefore, there was little improvement to the MLR models when compared to models using CART and RF. In general, the four modeling techniques (MLR, CART, RF, and BRT) consistently selected the same primary explanatory variables for each region. However, results from the BRT models showed significant improvement over the MLR models for each region; increases in R2 from 0.09 to 0.20. The O/E metric that was derived from models specifically calibrated for Oregon consistently had lower R2 values than RICHTOL for the two regions tested. Modeled O/E R2 values were between 0.06 and 0.10 lower for each of the four modeling methods applied in the Willamette Valley and were between 0.19 and 0.36 points lower for the Blue Mountains. As a result, BRT models may indeed represent a good alternative to MLR for modeling species distribution relative to environmental variables. 相似文献
696.
Melissa A. Kenney Peter R. Wilcock Benjamin F. Hobbs Nicholas E. Flores Daniela C. Martínez 《Journal of the American Water Resources Association》2012,48(3):603-615
Kenney, Melissa A., Peter R. Wilcock, Benjamin F. Hobbs, Nicholas E. Flores, and Daniela C. Martínez, 2012. Is Urban Stream Restoration Worth It? Journal of the American Water Resources Association (JAWRA) 48(3): 603-615. DOI: 10.1111/j.1752-1688.2011.00635.x Abstract: Public investment in urban stream restoration is growing, yet little has been done to quantify whether its benefits outweigh its cost. The most common drivers of urban stream projects are water quality improvement and infrastructure protection, although recreational and aesthetic benefits are often important community goals. We use standard economic methods to show that these contributions of restoration can be quantified and compared to costs. The approach is demonstrated with a case study in Baltimore, Maryland, a city with a legal mandate to reduce its pollutant load. Typical urban stream restoration costs of US$500-1,200 per foot are larger than the cost of the least expensive alternatives for management of nitrogen loads from stormwater (here, detention ponds, equivalent to $30-120 per foot of restored stream) and for protecting infrastructure (rip-rap armoring of streambanks, at $0-120 per foot). However, the higher costs of stream restoration can in some cases be justified by its aesthetic and recreational benefits, valued using a contingent valuation survey at $560-1,100 per foot. We do not intend to provide a definitive answer regarding the worth of stream restoration, but demonstrate that questions of worth can be asked and answered. Broader application of economic analysis would provide a defensible basis for understanding restoration benefits and for making restoration decisions. 相似文献
697.
698.
The need for transparency is taking more prominence in international climate negotiations as developed countries pledge large sums of money to foster adaptation efforts in developing countries. Tools that provide accurate and up-to-date spatial information that can be easily used and vetted by local practitioners may provide effective and affordable ways to improve transparency. The Global Adaptation Atlas is such a tool, combining vetted, publicly available climate impact data with timely maps of on the ground adaptation projects to highlight confluences of effects of climate change with actions taken to address those effects. Here, we describe the structure and general functions of the Global Adaptation Atlas and explain how it may be utilized to track short-term investments in adaptation. Over longer time scales, it may also help gauge the effectiveness of specific adaptation investments as well as reveal how different climate impacts affect long-term investment in differing regions. 相似文献
699.
The classic Microtox® solid phase assay (MSPA) based on the inhibition of light production of the marine bacteria recently renamed Aliivibrio fischeri suffers from various bias and interferences, mainly due to physico-chemical characteristics of the tested solid phase. To precisely assess ecotoxicity of sediments, we have developed an alternative method, named Microtox® leachate phase assay (MLPA), in order to measure the action of dissolved pollutants in the aqueous phase. Two hypotheses were formulated to explain the observed difference between MSPA and MLPA results: a real ecotoxicity of the solid phase or the fixation of bacteria to fine particles and/or organic matter. To estimate the latter, flow cytometry analyses were performed with two fluorochromes (known for their ability to stain bacterial DNA), allowing correction of MSPA measurements and generation of new (corrected) IC50. Comparison of results of MLPA with the new IC50 MSPA allows differentiating real ecotoxic and fixation effect in classic MSPA especially for samples with high amount of fines and/or organic matter. 相似文献
700.
Viau CM Cardone JM Guecheva TN Yoneama ML Dias JF Pungartnik C Brendel M Saffi J Henriques JA 《Chemosphere》2012,86(5):477-484
Tin or stannous (Sn2+) compounds are used as catalysts, stabilizers in plastic industries, wood preservatives, agricultural biocides and nuclear medicine. In order to verify the Sn2+ up-take and toxicity in yeast cells we utilized a multi-elemental analysis known as particle-induced X-ray emission (PIXE) along with cell survival assays and quantitative real-time PCR. The detection of Sn2+ by PIXE was possible only in yeast cells in stationary phase of growth (STAT cells) that survive at 25 mM Sn2+ concentration. Yeast cells in exponential phase of growth (LOG cells) tolerate only micro-molar Sn2+ concentrations that result in intracellular concentration below of the method detection limit. Our PIXE analysis showed that STAT XV185-14c yeast cells demonstrate a significant loss of intracellular elements such as Mg, Zn, S, Fe and an increase in P levels after 1 h exposure to SnCl2. The survival assay showed enhanced tolerance of LOG yeast cells lacking the low-affinity iron and zinc transporters to stannous treatment, suggesting the possible involvement in Sn2+ uptake. Moreover, our qRT-PCR data showed that Sn2+ treatment could generate reactive oxygen species as it induces activation of many stress-response genes, including SOD1, YAP1, and APN1. 相似文献