全文获取类型
收费全文 | 3539篇 |
免费 | 60篇 |
国内免费 | 33篇 |
专业分类
安全科学 | 203篇 |
废物处理 | 116篇 |
环保管理 | 946篇 |
综合类 | 324篇 |
基础理论 | 865篇 |
环境理论 | 7篇 |
污染及防治 | 786篇 |
评价与监测 | 224篇 |
社会与环境 | 131篇 |
灾害及防治 | 30篇 |
出版年
2023年 | 15篇 |
2022年 | 23篇 |
2021年 | 27篇 |
2020年 | 26篇 |
2019年 | 35篇 |
2018年 | 43篇 |
2017年 | 64篇 |
2016年 | 85篇 |
2015年 | 73篇 |
2014年 | 75篇 |
2013年 | 447篇 |
2012年 | 132篇 |
2011年 | 175篇 |
2010年 | 117篇 |
2009年 | 132篇 |
2008年 | 157篇 |
2007年 | 194篇 |
2006年 | 136篇 |
2005年 | 118篇 |
2004年 | 124篇 |
2003年 | 127篇 |
2002年 | 108篇 |
2001年 | 63篇 |
2000年 | 78篇 |
1999年 | 49篇 |
1998年 | 56篇 |
1997年 | 44篇 |
1996年 | 61篇 |
1995年 | 57篇 |
1994年 | 64篇 |
1993年 | 52篇 |
1992年 | 47篇 |
1991年 | 39篇 |
1990年 | 38篇 |
1989年 | 31篇 |
1988年 | 40篇 |
1987年 | 30篇 |
1986年 | 34篇 |
1985年 | 33篇 |
1984年 | 30篇 |
1983年 | 37篇 |
1982年 | 48篇 |
1981年 | 47篇 |
1980年 | 25篇 |
1979年 | 28篇 |
1978年 | 25篇 |
1977年 | 29篇 |
1976年 | 13篇 |
1974年 | 10篇 |
1972年 | 11篇 |
排序方式: 共有3632条查询结果,搜索用时 109 毫秒
811.
812.
Katarzyna Naylor Anna Torres Robert Gałązkowski Kamil Torres 《International journal of occupational safety and ergonomics》2019,25(4):597-603
Introduction. Paramedics are at risk of occupational blood exposure, increased by the immediacy of provided treatment. However, the issue has not been acknowledged to date by any research in Europe. Methods. This research aimed at assessing occupational blood exposure among paramedics in Poland. Respondents represented 21 Polish medical institutions. Their participation was voluntary and anonymous. Paramedics were provided with a self-directed job-specific questionnaire adapted to Polish conditions from an original US version. Results. 118 paramedics participated in the study from institutions constituting the National Emergency Medical System in Poland; including ambulance crews, Helicopter Emergency Medical Services and emergency department employees. Occupational exposure was reported by 18.64% of respondents and the main route of exposure was needlestick events. Conclusions. There is a further need to improve education among paramedics concerning the threat of being infected with blood-borne pathogens through all existing routes. Our findings point to the problem as being hidden and considered a shameful issue. 相似文献
813.
The present study examined the moderating role of reciprocation wariness in the association of employees' psychological contract fulfillment with psychosomatic strain and voluntary turnover, as mediated by perceived organizational support. To study these relationships longitudinally, 169 graduating college seniors were surveyed upon job acceptance and again 3 weeks, 3 months, 6 months, and 18 months following the start of employment. The findings showed that psychological contract fulfillment was positively related to perceived organizational support. However, this positive relationship was eliminated by reciprocation wariness, and this influence was carried over to psychosomatic strain and voluntary turnover. Thus, it appears that reciprocation wariness leads employees to discount psychological contract fulfillment as an indication of the organization's valuation and caring. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
814.
Christophe Guimbau Cécile Noel Michel Chartier Valéry Catoire Michaela Blessing Jean Christophe Gourry Claude Robert 《环境科学学报(英文版)》2016,28(2):60-74
Real-time methods to monitor stable isotope ratios of CO_2 are needed to identify biogeochemical origins of CO_2 emissions from the soil–air interface. An isotope ratio infra-red spectrometer(IRIS) has been developed to measure CO_2 mixing ratio with δ~13C isotopic signature, in addition to mixing ratios of other greenhouse gases(CH_4, N2_O). The original aspects of the instrument as well as its precision and accuracy for the determination of the isotopic signature δ~13C of CO_2 are discussed. A first application to biodegradation of hydrocarbons is presented, tested on a hydrocarbon contaminated site under aerobic bio-treatment. CO_2 flux measurements using closed chamber method is combined with the determination of the isotopic signature δ~13C of the CO_2 emission to propose a non-intrusive method to monitor in situ biodegradation of hydrocarbons. In the contaminated area, high CO_2 emissions have been measured with an isotopic signature δ~13C suggesting that CO_2 comes from petroleum hydrocarbon biodegradation.This first field implementation shows that rapid and accurate measurement of isotopic signature of CO_2 emissions is particularly useful in assessing the contribution of contaminant degradation to the measured CO_2 efflux and is promising as a monitoring tool for aerobic bio-treatment. 相似文献
815.
Mariana M. P. B. Fuentes Lynda Chambers Andrew Chin Peter Dann Kirstin Dobbs Helene Marsh Elvira S. Poloczanska Kim Maison Malcolm Turner Robert L. Pressey 《Mitigation and Adaptation Strategies for Global Change》2016,21(2):209-224
Management of marine mega-fauna in a changing climate is constrained by a series of uncertainties, often related to climate change projections, ecological responses, and the effectiveness of strategies in alleviating climate change impacts. Uncertainties can be reduced over time through adaptive management. Adaptive management is a framework for resource conservation that promotes iterative learning-based decision making. To successfully implement the adaptive management cycle, different steps (planning, designing, learning and adjusting) need to be systematically implemented to inform earlier steps in an iterative way. Despite the critical role that adaptive management is likely to play in addressing the impacts of climate change on marine mega-fauna few managers have successfully implemented an adaptive management approach. We discuss the approaches necessary to implement each step of an adaptive management cycle to manage marine mega-fauna in a changing climate, highlighting the steps that require further attention to fully implement the process. Examples of sharks and rays (Selachimorpha and Batoidea) on the Great Barrier Reef and little penguins, Eudyptula minor, in south-eastern Australia are used as case studies. We found that successful implementation of the full adaptive management cycle to marine mega-fauna needs managers and researchers to: (1) obtain a better understanding of the capacity of species to adapt to climate change to inform the planning step; (2) identify strategies to directly address impacts in the marine environment to inform the designing step; and (3) develop systematic evaluation and monitoring programs to inform the learning step. Further, legislation needs to flexible to allow for management to respond. 相似文献
816.
Stéphane Roujol Robert Joumard 《Atmospheric environment (Oxford, England : 1994)》2009,43(5):1008-1014
The impact of the auxiliaries and particularly air conditioning on emissions (CO2, CO, HC, NOx and particles) is investigated. To this aim, various data from European laboratories are used and analysed. Parameters linked to technology and to climatic conditions are investigated. The main distinction is made between gasoline and diesel vehicles. A physical model is proposed to extrapolate the excess emissions at low temperature (below 28 °C) and with solar radiation, together with a statistical model. 相似文献
817.
Retreat and advance of shoreline position occurs naturally, and also as a result of defences which are constructed to prevent
erosion and flooding. Retreat more commonly manifests itself down-drift of defences due to a sediment deficit causing the
coast to become ‘set-back’. Advance normally develops due to sediment accumulation up-drift of a barrier inhibiting longshore
drift, resulting in the coast becoming ‘set-forward’. Many examples of set-backs and set-forwards are recorded, but their
location, number and cause is not known on a national scale. Using the Futurecoast aerial photographs, approximately 200 localities
were identified as set-back or set-forward in England and Wales, with half situated in the Eastern and South East regions
of England. Half of the total set-backs or set-forwards were on cliffed coasts, and half on low-lying coasts. Without local
knowledge it is difficult to distinguish between set-backs and set-forwards. Set-backs often indicate higher retreat rates,
thus threatening cliff-top infrastructure which requires defence upgrade and extensions, as well as raising maintenance costs.
Monitoring set-backs is important for shoreline management, because as retreat continues, set-backs evolve and artificial
headlands form and grow. This is reinforced by the shift from hard defence policies towards softer engineering approaches,
managed realignment and limited intervention. 相似文献
818.
Maria João Cruz Elisabeth Maria Rogier Robert Tiago Costa David Avelar Rui Rebelo Mário Pulquério 《Regional Environmental Change》2016,16(5):1293-1304
Assessing biodiversity vulnerability to future climate change is essential for developing robust adaptation strategies. A number of vulnerability assessment methodologies have been developed, from bioclimatic envelop models to more complex approaches that also consider biological traits and population status. However, the lack of comparative studies leaves the user to choose among the different methodologies without much guidance. This study applied three vulnerability assessment approaches to the Portuguese herpetofauna: (I) impact assessment approach based on bioclimatic models; (II) integrated vulnerability assessment approach, adding the evaluation of adaptive capacity to approach I; and (III) integrated vulnerability assessment and validation based on expert consultation. Results showed disagreement between the different approaches for 19 % of the species studied. Most differences were found between approach III and the two other approaches. All approaches showed advantages and limitations, the choice of a methodology being ultimately dependent on the study goals. Approach I has proven efficient to capture general vulnerability patterns. Approach II, although presenting results similar to approach I, allows for the identification of key factors affecting the species adaptive capacity and may be useful in tailoring adaptation measures. Approach III further allows us to identify knowledge gaps and to evaluate vulnerability when data availability or quality is reduced. Further, because this approach is based on an expert workshop, it has proven a perfect means to build on the vulnerability assessment results to identify indicator species and prioritize specific adaptation options. 相似文献
819.
All U.S. federal agencies administering environmental laws purport to practice adaptive management (AM), but little is known about how they actually implement this conservation tool. A gap between the theory and practice of AM is revealed in judicial decisions reviewing agency adaptive management plans. We analyzed all U.S. federal court opinions published through 1 January 2015 to identify the agency AM practices courts found most deficient. The shortcomings included lack of clear objectives and processes, monitoring thresholds, and defined actions triggered by thresholds. This trio of agency shortcuts around critical, iterative steps characterizes what we call AM‐lite. Passive AM differs from active AM in its relative lack of management interventions through experimental strategies. In contrast, AM‐lite is a distinctive form of passive AM that fails to provide for the iterative steps necessary to learn from management. Courts have developed a sophisticated understanding of AM and often offer instructive rather than merely critical opinions. The role of the judiciary is limited by agency discretion under U.S. administrative law. But courts have overturned some agency AM‐lite practices and insisted on more rigorous analyses to ensure that the promised benefits of structured learning and fine‐tuned management have a reasonable likelihood of occurring. Nonetheless, there remains a mismatch in U.S. administrative law between the flexibility demanded by adaptive management and the legal objectives of transparency, public participation, and finality. 相似文献
820.