全文获取类型
收费全文 | 885篇 |
免费 | 43篇 |
国内免费 | 13篇 |
专业分类
安全科学 | 38篇 |
废物处理 | 32篇 |
环保管理 | 205篇 |
综合类 | 106篇 |
基础理论 | 294篇 |
环境理论 | 1篇 |
污染及防治 | 180篇 |
评价与监测 | 43篇 |
社会与环境 | 30篇 |
灾害及防治 | 12篇 |
出版年
2023年 | 8篇 |
2022年 | 21篇 |
2021年 | 17篇 |
2020年 | 25篇 |
2019年 | 20篇 |
2018年 | 29篇 |
2017年 | 48篇 |
2016年 | 32篇 |
2015年 | 34篇 |
2014年 | 35篇 |
2013年 | 80篇 |
2012年 | 52篇 |
2011年 | 65篇 |
2010年 | 49篇 |
2009年 | 38篇 |
2008年 | 46篇 |
2007年 | 47篇 |
2006年 | 39篇 |
2005年 | 25篇 |
2004年 | 25篇 |
2003年 | 26篇 |
2002年 | 20篇 |
2001年 | 16篇 |
2000年 | 10篇 |
1999年 | 13篇 |
1998年 | 9篇 |
1997年 | 17篇 |
1996年 | 8篇 |
1995年 | 11篇 |
1994年 | 6篇 |
1993年 | 4篇 |
1992年 | 4篇 |
1991年 | 5篇 |
1990年 | 8篇 |
1989年 | 7篇 |
1987年 | 6篇 |
1986年 | 5篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1983年 | 5篇 |
1982年 | 6篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1968年 | 1篇 |
1966年 | 2篇 |
排序方式: 共有941条查询结果,搜索用时 296 毫秒
331.
The social spider Anelosimus studiosus exhibits a behavioral polymorphism where colony members express either a passive, tolerant behavioral tendency (social) or
an aggressive, intolerant behavioral tendency (asocial). Here we test whether asocial individuals act as colony defenders
by deflecting the suite of foreign (i.e., heterospecific) spider species that commonly exploit multi-female colonies. We (1)
determined whether the phenotypic composition of colonies is associated with foreign spider abundance, (2) tested whether
heterospecific spider abundance and diversity affect colony survival in the field, and (3) performed staged encounters between
groups of A. studiosus and their colony-level predator Agelenopsis emertoni (A. emertoni)to determine whether asocial females exhibit more defensive behavior. We found that larger colonies harbor more foreign spiders,
and the number of asocial colony members was negatively associated with foreign spider abundance. Additionally, colony persistence
was negatively associated with the abundance and diversity of foreign spiders within colonies. In encounters with a colony-level
predator, asocial females were more likely to exhibit escalatory behavior, and this might explain the negative association
between the frequency of asocial females and the presence of foreign spider associates. Together, our results indicate that
foreign spiders are detrimental to colony survival, and that asocial females play a defensive role in multi-female colonies. 相似文献
332.
Jonathan N. Pruitt Nicholas DiRienzo Simona Kralj-Fišer J. Chadwick Johnson Andrew Sih 《Behavioral ecology and sociobiology》2011,65(10):1987-1995
Research on consistent individual differences in behavior, or “behavioral syndromes”, continues to grow rapidly, and yet,
the aspects of behavior under consideration have remained remarkably limited. Here, we consider individual variation in consistency
of choice (termed here “choosiness”), as expressed during habitat choice. We repeatedly tested the responses of female Western
Black Widows, Latrodectus hesperus, to two cues of habitat quality: prey chemical cues and variation in web site illuminance. We estimated females’ response
by the distance they positioned themselves from (1) the source of prey chemical cues and (2) the darkest edge of our test
arena. Individuals with low variance in their responses are deemed more “choosy”, whereas individuals with high variance are
deemed less “choosy”. Generally, most females initiated web construction near the source of the prey chemical cues and tended
to place themselves in low-light conditions. However, we detected strong, repeatable differences in females’ intensity of
response, and within-individual variance of response (i.e., choosiness) was correlated across situations: females with highly
consistent responses towards cricket chemical cues also exhibited highly consistent responses towards variation in light conditions.
When deprived of food for extended periods, females were indistinguishable in their responses towards prey chemical cues,
but tended to initiate web construction in brighter lighting conditions. Food-deprived females universally exhibited higher
variance and diminished consistency in their responses (i.e., they were less choosy). Additionally, higher choosiness was
associated with greater mass loss during choice trials, suggesting choosiness is energetically costly. Our results demonstrate
that consistency of response to environmental cues is yet another element of behavior that varies among individuals and variation
in choosiness could beget speed/quality trade-offs during animal decision making. 相似文献
333.
Dong-Ha Nam Douglas H. Adams Eric A. Reyier Niladri Basu 《Environmental monitoring and assessment》2011,176(1-4):549-559
Tissue levels of mercury (Hg; total, organic) and selenium (Se) were assessed in juvenile lemon sharks (Negaprion brevirostris) from Florida nearshore waters collected during a harmful algal bloom (HAB, brevetoxin) event and compared with sharks not exposed to HABs. In all sharks studied, total Hg levels in the muscle were generally present in a molar excess over Se (which may protect against Hg toxicity) and mean muscle Hg levels (0.34 $\upmu $ g/g) exceed safe human consumption guidelines. While there was generally no difference in tissue Hg and Se levels following exposure of sharks to HABs, hepatic Hg levels were significantly lower (56% reduction) in the HAB-exposed sharks compared to controls. As Hg and HABs are globally increasing in scope and magnitude, further work is warranted to assess their interactions and biotic impacts within aquatic ecosystems, especially for a species such as the lemon shark that is classified as a near-threatened species by the International Union for the Conservation of Nature. 相似文献
334.
Cat Button Maria Adelaida Antonette Mias-Mamonong Bernhard Barth Jonathan Rigg 《Local Environment》2013,18(6):705-722
Sorsogon City is a rapidly urbanising coastal area in the Philippines. Its location, combined with a rapidly changing and growing urban fabric, leaves it vulnerable to both incremental climate change and associated extreme weather events. In this paper, UN-HABITAT data are used to draw out the climate change vulnerabilities and policy responses in Sorsogon City. Vulnerability “hotspots” highlight the spatial intersection of socio-economic justice concerns, particularly in terms of vulnerability to increased cyclone activity. We discuss vulnerabilities of Sorsogon City and its citizens to climate change and measures undertaken through various social, environmental and technical systems and interventions to increase resilience. The paper also attempts to unpick the relationship between the neat, concise reported city and the complexities of urban life using the Sorsogon experiment to consider the limitations of such approaches to governing climate change. We group these under four headings: social simplification in the absence of data; over-governance (and under-representation); quick wins versus strategic investment; and stretching the ecological and vulnerability footprints of the city. The experience of Sorsogon City is then extended to reflect on issues of governance and planning in other Asian coastal cities. 相似文献
335.
336.
A simple rapid chromatographic technique for polycyclic aromatic hydrocarbons which is poor at speciation has been used to obtain data on the presence of the class in air particulate. Matching of such chromatograms to a fuzzified reference from these data is illustrated as a practical way to obtain overviews of changes in species distributions summarized in few values. Such information is lost in more commonly used surrogate approaches to “class analyses”. 相似文献
337.
I. D. Hodge W. M. Adams N. A. D. Bourn 《Journal of Environmental Planning and Management》1994,37(2):199-213
While there has been considerable change in the economy and environment of the UK countryside in the post‐war period, the basic divisions of responsibility of government agencies still reflect the framework established in the 1940s. However, the functions of these agencies have changed and expanded to embrace new environmental responsibilities. This ‘agency overspill’ leaves the definition of responsibilities of countryside agencies unclear and raises the issue of competition between them. It is argued that competition need not be counterproductive where agencies fill distinctive roles and where there is some degree of co‐ordination. 相似文献
338.
In many semi-arid areas, estuaries are threatened because of freshwater impoundment. Estuaries are important sites for ecological
diversity and, increasingly, for recreation. A system has been developed which rates estuaries according to their botanical
importance. A formula allows a single numerical importance score to be calculated. The area cover of each estuarine plant
community type (i.e. intertidal salt marsh, submerged macrophytes, reed/sedge swamps and supratidal salt marsh) and its importance
in the estuary forms the basis of the score. The ‘ecological condition’ of the plant community and the community richness
within the estuary are incorporated into the formula. The formula is effective in determining the botanical importance of
estuaries. Further methods to determine the zoological, physical and socio-economic importance of estuaries need to be developed
to allow the overall importance of estuaries to be determined. 相似文献
339.
340.
Jonathan J. Waters Sally Walsh Lisa J. Levett Stuart Liddle Yinka Akinfenwa 《黑龙江环境通报》2006,26(10):892-897
A chorion villus sample (CVS) biopsied at 11 weeks' gestation for raised nuchal translucency, revealed monosomy X (presumptive 45,X karyotype) by QF-PCR for rapid aneuploidy testing for chromosomes 13, 18, 21, X and Y. Long-term culture gave the karyotype: 47,XY,+ 21[66]/49,XYY,+ 21,+ 21 [22]. This discrepancy prompted redigestion of the combined residual villus fragments from the original QF-PCR assay. The repeat QF-PCR assay identified the presence of trisomy 21 and a Y chromosome consistent with a 47,XY,+ 21 karyotype. A double non-disjunction event early in embryogenesis in a 47,XY,+ 21 conceptus with subsequent cell lineage compartmentalisation of the three observed cell lines (45,X; 47,XY,+ 21 and 49,XYY,+ 21,+ 21) would account for these results. This is the first reported case to describe complete discrepancy at diagnosis between abnormal karyotypes detected by QF-PCR rapid aneuploidy testing and a cultured karyotype in the same CVS. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献