全文获取类型
收费全文 | 244篇 |
免费 | 6篇 |
国内免费 | 1篇 |
专业分类
安全科学 | 11篇 |
废物处理 | 6篇 |
环保管理 | 52篇 |
综合类 | 28篇 |
基础理论 | 58篇 |
污染及防治 | 67篇 |
评价与监测 | 21篇 |
社会与环境 | 7篇 |
灾害及防治 | 1篇 |
出版年
2023年 | 2篇 |
2022年 | 2篇 |
2021年 | 4篇 |
2020年 | 3篇 |
2019年 | 3篇 |
2018年 | 3篇 |
2017年 | 4篇 |
2016年 | 4篇 |
2015年 | 2篇 |
2014年 | 6篇 |
2013年 | 21篇 |
2012年 | 12篇 |
2011年 | 9篇 |
2010年 | 9篇 |
2009年 | 9篇 |
2008年 | 9篇 |
2007年 | 12篇 |
2006年 | 15篇 |
2005年 | 7篇 |
2004年 | 6篇 |
2003年 | 7篇 |
2002年 | 9篇 |
2001年 | 10篇 |
2000年 | 4篇 |
1999年 | 6篇 |
1998年 | 5篇 |
1996年 | 1篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 3篇 |
1991年 | 6篇 |
1990年 | 3篇 |
1989年 | 1篇 |
1988年 | 6篇 |
1987年 | 2篇 |
1986年 | 4篇 |
1985年 | 6篇 |
1984年 | 7篇 |
1982年 | 3篇 |
1981年 | 5篇 |
1980年 | 1篇 |
1979年 | 3篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1970年 | 1篇 |
1969年 | 3篇 |
1966年 | 1篇 |
1934年 | 1篇 |
排序方式: 共有251条查询结果,搜索用时 31 毫秒
131.
132.
Payments for Environmental Services (PES) is gaining recognition worldwide as a serious option for conservation of ecosystems, as well as potentially improving the livelihoods of people providing environmental services. However, little attention has been paid to research on views of local people in their potential roles as service providers. In this research we explore perspectives of poor people living in a National Park in Vietnam, where introduction of PES is being considered. In-depth interviews and workshops were conducted – with strong emphasis on the use of visual techniques, to help facilitate learning processes and provide insight into local perspectives. From the research, two models were developed to indicate general factors that influence the likelihood of people adopting, and adhering to, PES schemes. We suggest these models can be used to guide the design of PES. Our findings also reveal three main requirements important in design of pro-poor PES: (1) Thorough scoping studies for ensuring that schemes are based on sound understanding of potential providers' perspectives and context. (2) Such studies should emphasise qualitative research and draw on participatory tools, to facilitate open dialogue and co-learning by researchers and participants. (3) Policy makers should consider designing hybridized schemes, i.e., in which PES concepts are combined with integrated conservation and development. 相似文献
133.
Dawson JJ Campbell CD Towers W Cameron CM Paton GI 《Environmental pollution (Barking, Essex : 1987)》2006,142(3):493-500
Soils bind heavy metals according to fundamental physico-chemical parameters. Bioassays, using bacterial biosensors, were performed in pore waters extracted from 19 contrasting soils individually amended with Cd, Cu and Zn concentrations related to the EU Sewage Sludge Directive. The biosensors were responsive to pore waters extracted from Zn amended soils but less so to those of Cu and showed no toxicity to pore water Cd at these environmentally relevant amended concentrations. Across the range of soils, the solid-solution heavy metal partitioning coefficient (K(d)) decreased (p<0.01) with increasing amendments of Cu and Zn; Cu exhibited the highest K(d) values. Gompertz functions of Cu and Zn, K(d) values against luminescence explained the relationship between heavy metals and biosensors. Consequently, biosensors provide a link between biologically defined hazard assessments of metals and standard soil-metal physico-chemical parameters for determining critical metal loadings in soils. 相似文献
134.
Campbell O. Webb 《Conservation biology》1999,13(6):1520-1521
135.
Carl P. Maertz Jr Rodger W. Griffeth Nathanael S. Campbell David G. Allen 《组织行为杂志》2007,28(8):1059-1075
This study examines mediated effects of perceived supervisor support (PSS) and perceived organizational support (POS) on turnover cognitions, and their interactive effects on turnover behavior in a sample of 225 social services workers. In this study, we address a seeming contradiction in current findings regarding support and attachments to managers versus attachments to the organization itself. The POS literature suggests fully mediated causal paths to turnover from POS and PSS, through affective commitment. Whereas, the commitment, LMX, and turnover literatures suggest alternative causal paths that imply broader effects for POS and PSS on turnover. Contrary to earlier POS literature, findings showed that PSS had independent effects on turnover cognitions not mediated through POS. Model tests also indicated that POS had significant effects on turnover mediated through normative commitment, as well as affective organizational commitment. Moreover, a new significant interactive relationship was discovered such that low PSS strengthened the negative relationship between POS and turnover, while high PSS weakened it. Implications for research and practice are discussed. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
136.
137.
Phytoremediation is an emerging technique that can be used to economically remediate sites contaminated with trace elements and/or man‐made organic contaminants. This technique was used on Pearl Harbor (Oahu, Hawaii) dredged material (PHDM) containing polycyclic aromatic hydrocarbons (PAHs) and some heavy metals. The dredged material was first amended with a high‐calcium soil (Waialua Mollisol) and a biosolids‐based compost at different proportions to yield varying salinity levels. A mixture that yielded an electrical conductivity (EC, a measure of salinity) of the saturated paste extract of 15 to 20 dS/m was identified and used to evaluate the salt tolerance of five plant species. Relative germination and one‐month‐old biomass indicated that common bermuda grass (Cynodon dactylon), seashore paspalum (Paspalum vaginatum), beach pea (Vigna marina), and cow pea (Vigna unguiculata) can produce at least 40 percent of biomass of the control at an EC of approximately 18 dS/m, suggesting the four plants are relatively salt tolerant. In contrast, Desmodium intortum either did not germinate or died within two weeks after germination at the same salinity level. A subsequent greenhouse experiment, using mixtures of the PHDM (0 or 25 percent dry weight), organic amendments (10 percent leucaena green manure or biosolids‐based compost), and a Mollisol (65 or 90 percent dry weight) in 6‐liter pots containing 4 kilograms of material yielded the following results: (1) A combination of transplanted seashore paspalum, seeded bermuda grass, and seeded beach pea was effective in taking up sodium (Na), thereby reducing salinity and making the medium more amenable to diversified microbes and plants, which may be effective PAH degraders; (2) total PAH concentration was reduced by about 30 percent after three months of active plant growth, but degradation of individual PAH members varied significantly, however; (3) leguminous green manure, as a soil amendment, was more effective than compost for use in bio‐ and/or phytoremediations; and (4) soil amendments, when applicable, could supplement living plants in reducing organic contaminants, such as PAHs. © 2002 Wiley Periodicals, Inc. 相似文献
138.
A case of prenatal diagnosis of an overgrowth syndrome at 30 weeks of gestation is reported. The diagnosis was suggested on the basis of increased fetal growth from 16 weeks onwards, advanced bone age, and characteristic facial features such as hypertelorism, broad forehead and small chin. The fetus presented at 12 weeks with a markedly increased nuchal translucency thickness and generalized skin edema, but normal karyotype. Serial ultrasound scans revealed brain abnormalities including mild unilateral ventriculomegaly and a cyst in the cavum septi pellucidi. The pregnancy was terminated at the parents' request at 32 weeks of gestation and postmortem examination confirmed the prenatal findings. This case demonstrates the possibility of prenatal diagnosis of early overgrowth syndromes and highlights the dilemma arising from the prenatal diagnosis of a non-lethal condition associated with an uncertain prognosis and poorly documented in utero. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
139.
140.