全文获取类型
收费全文 | 747篇 |
免费 | 31篇 |
国内免费 | 6篇 |
专业分类
安全科学 | 46篇 |
废物处理 | 29篇 |
环保管理 | 232篇 |
综合类 | 53篇 |
基础理论 | 183篇 |
环境理论 | 3篇 |
污染及防治 | 154篇 |
评价与监测 | 57篇 |
社会与环境 | 22篇 |
灾害及防治 | 5篇 |
出版年
2023年 | 7篇 |
2022年 | 3篇 |
2021年 | 10篇 |
2020年 | 6篇 |
2019年 | 11篇 |
2018年 | 15篇 |
2017年 | 27篇 |
2016年 | 26篇 |
2015年 | 20篇 |
2014年 | 30篇 |
2013年 | 64篇 |
2012年 | 37篇 |
2011年 | 47篇 |
2010年 | 35篇 |
2009年 | 44篇 |
2008年 | 40篇 |
2007年 | 37篇 |
2006年 | 46篇 |
2005年 | 35篇 |
2004年 | 31篇 |
2003年 | 25篇 |
2002年 | 33篇 |
2001年 | 14篇 |
2000年 | 10篇 |
1999年 | 14篇 |
1998年 | 12篇 |
1997年 | 9篇 |
1996年 | 9篇 |
1995年 | 8篇 |
1994年 | 13篇 |
1993年 | 8篇 |
1992年 | 5篇 |
1991年 | 3篇 |
1990年 | 7篇 |
1989年 | 2篇 |
1988年 | 6篇 |
1987年 | 2篇 |
1985年 | 5篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 4篇 |
1981年 | 3篇 |
1980年 | 4篇 |
1979年 | 3篇 |
1978年 | 1篇 |
1977年 | 3篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1968年 | 1篇 |
排序方式: 共有784条查询结果,搜索用时 0 毫秒
781.
Andrew D. Ashton Jeffrey P. Donnelly Rob L. Evans 《Mitigation and Adaptation Strategies for Global Change》2008,13(7):719-743
An increase in the rate of sea-level rise and potential changes in storminess represent important components of global climate
change that will likely affect the extensive coasts of the Northeastern USA. Raising sea level not only increases the likelihood
of coastal flooding, but changes the template for waves and tides to sculpt the coast, which can lead to land loss orders
of magnitude greater than that from direct inundation alone. There is little question that sea-level rise, and in particular
an increased rate of rise, will result in permanent losses of coastal land. However, quantitative predictions of these future
coastal change remains difficult due in part to the complexity of coastal systems and the influence of infrequent storm events,
and is further confounded by coastal science’s insufficient understanding of the behavior of coastal systems over decadal
timescales. Recently, dramatic improvements in technology have greatly improved our capabilities to investigate and characterize
processes and sedimentary deposits in the coastal zone, allowing us, for the first time, to address some of the over-arching
problems involved in shoreline change. Despite advances in many areas of coastal geology, our fundamental understanding of
shoreline change has been limited by a lack of a broad and integrated scientific focus, a lack of resources, and a lack of
willingness on the part of policymakers who make crucial decisions about human activity along the coast to support basic research
in this area. Although quantitative predictions remain constrained, there remains little doubt that the predicted climates
changes will have profound effects upon the Northeastern coast. 相似文献
782.
Relationship between protean career orientation and work–life balance: A resource perspective 下载免费PDF全文
Despite the commonly held belief that a protean career orientation (PCO) enables employees to achieve more balance in their lives, little is known about the relationship between PCO and work–life balance. Using two waves of data collection separated by 2.5 years, this study examined the relationship between PCO and work–life balance among a sample of 367 college‐educated employees in the United States. Analysis was conducted to empirically distinguish PCO from conceptually related constructs, and structural equation modeling was used to examine the process that explains the linkage between PCO and balance. We found that PCO was positively related to work–life balance. We also found support for the role of several resources (social capital, psychological capital, and perceived employability) that explain the relationship between PCO and balance. In particular, PCO was associated with extensive career planning activities that were related to the accumulation of three forms of career capital—human capital, social capital, and psychological capital. In turn, social capital and psychological capital were associated with high employability, which was related to greater work–life balance for individuals who take a whole‐life perspective on their careers. We discuss the theoretical and practical implications of the findings and provide suggestions for future research. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
783.
Jeffrey O. Hanson Ana Veríssimo Guillermo Velo-Antón Adam Marques Miguel Camacho-Sanchez Íñigo Martínez-Solano Helena Gonçalves Fernando Sequeira Hugh P. Possingham Silvia B. Carvalho 《Conservation biology》2021,35(2):634-642
Protected-area systems should conserve intraspecific genetic diversity. Because genetic data require resources to obtain, several approaches have been proposed for generating plans for protected-area systems (prioritizations) when genetic data are not available. Yet such surrogate-based approaches remain poorly tested. We evaluated the effectiveness of potential surrogate-based approaches based on microsatellite genetic data collected across the Iberian Peninsula for 7 amphibian and 3 reptilian species. Long-term environmental suitability did not effectively represent sites containing high genetic diversity (allelic richness). Prioritizations based on long-term environmental suitability had similar performance to random prioritizations. Geographic distances and resistance distances based on contemporary environmental suitability were not always effective surrogates for identification of combinations of sites that contain individuals with different genetic compositions. Our results demonstrate that population genetic data based on commonly used neutral markers can inform prioritizations, and we could not find an adequate substitute. Conservation planners need to weigh the potential benefits of genetic data against their acquisition costs. 相似文献
784.
Lee T Kreidenweis SM Collett JL 《Journal of the Air & Waste Management Association (1995)》2004,54(5):585-592
The ionic compositions of particulate matter with aerodynamic diameter < or = 2.5 microm (PM2.5) and size-resolved aerosol particles were measured in Big Bend National Park, Texas, during the 1999 Big Bend Regional Aerosol and Visibility Observational study. The ionic composition of PM2.5 aerosol was dominated by sulfate (SO4(2-)) and ammonium (NH4+). Daily average SO4(2-) and NH4+ concentrations were strongly correlated (R2 = 0.94). The molar ratio of NH4+ to SO4(2-) averaged 1.54, consistent with concurrent measurements of aerosol acidity. The aerosol was observed to be comprised of a submicron fine mode consisting primarily of ammoniated SO4(2-) and a coarse particle mode containing nitrate (NO3-). The NO3- appears to be primarily associated with sea salt particles where chloride has been replaced by NO3-, although formation of calcium nitrate (Ca(NO3)2) is important, too, on several days. Size-resolved aerosol composition results reveal that a size cut in particulate matter with aerodynamic diameter < or = 1 microm would have provided a much better separation of fine and coarse aerosol modes than the standard PM2.5 size cut utilized for the study. Although considerable nitric acid exists in the gas phase at Big Bend, the aerosol is sufficiently acidic and temperatures sufficiently high that even significant future reductions in PM2.5 SO4(2-) are unlikely to be offset by formation of particulate ammonium nitrate in summer or fall. 相似文献