全文获取类型
收费全文 | 973篇 |
免费 | 7篇 |
国内免费 | 11篇 |
专业分类
安全科学 | 19篇 |
废物处理 | 23篇 |
环保管理 | 97篇 |
综合类 | 185篇 |
基础理论 | 197篇 |
环境理论 | 5篇 |
污染及防治 | 343篇 |
评价与监测 | 73篇 |
社会与环境 | 46篇 |
灾害及防治 | 3篇 |
出版年
2023年 | 7篇 |
2022年 | 26篇 |
2021年 | 21篇 |
2020年 | 16篇 |
2019年 | 17篇 |
2018年 | 34篇 |
2017年 | 28篇 |
2016年 | 66篇 |
2015年 | 39篇 |
2014年 | 51篇 |
2013年 | 74篇 |
2012年 | 65篇 |
2011年 | 81篇 |
2010年 | 44篇 |
2009年 | 41篇 |
2008年 | 66篇 |
2007年 | 57篇 |
2006年 | 45篇 |
2005年 | 35篇 |
2004年 | 38篇 |
2003年 | 31篇 |
2002年 | 22篇 |
2001年 | 12篇 |
2000年 | 13篇 |
1999年 | 3篇 |
1998年 | 2篇 |
1997年 | 6篇 |
1996年 | 5篇 |
1995年 | 3篇 |
1994年 | 4篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1990年 | 3篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 4篇 |
1980年 | 2篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1968年 | 1篇 |
1965年 | 1篇 |
1961年 | 1篇 |
1952年 | 1篇 |
排序方式: 共有991条查询结果,搜索用时 15 毫秒
931.
Peter H. Kahn Jr. Batya Friedman Brian Gill Jennifer Hagman Rachel L. Severson Nathan G. Freier Erika N. Feldman Sybil Carrre Anna Stolyar 《Journal of environmental psychology》2008,28(2):192-199
Humans will continue to adapt to an increasingly technological world. But are there costs to such adaptations in terms of human well being? Toward broaching this question, we investigated physiological effects of experiencing a HDTV quality real-time view of nature through a plasma display “window.” In an office setting, 90 participants (30 per group) were exposed either to (a) a glass window that afforded a view of a nature scene, (b) a plasma window that afforded a real-time HDTV view of essentially the same scene, or (c) a blank wall. Results showed that in terms of heart rate recovery from low-level stress the glass window was more restorative than a blank wall; in turn, a plasma window was no more restorative than a blank wall. Moreover, when participants spent more time looking at the glass window, their heart rate tended to decrease more rapidly; that was not the case with the plasma window. Discussion focuses on how the purported benefits of viewing nature may be attenuated by a digital medium. 相似文献
932.
S. Kanafani A. Aboura E. Pipiras L. Carbillon A. C. Tabet C. Largillière C. Garel P. Gressens M. Bucourt I. Cedrin-Durnerin E. Lachassinne C. Roumegoux M. Uzan J. N. Hugues J. P. Wolf B. Benzacken 《黑龙江环境通报》2007,27(3):279-284
We report a semilobar holoprosencephaly (HPE) in a post-intracytoplasmic-sperm-injection pregnancy. It was suggested by ultrasonography (US), documented on karyotype, identified with magnetic resonance imaging (MRI), established after birth and confirmed on post-mortem autopsy. An amniocentesis revealed a de novo apparently balanced reciprocal translocation 46,XY, t(7;8) (q31.3;q12). Fluorescence in situ hybridization (FISH) identified a deletion in the region of the Sonic Hedgehog gene (SHH) on der(8); nevertheless, the subtelomeric regions for chromosomes 7 and 8 were present. The parents decided to continue the pregnancy; a boy was born and survived for 3 days. The brain autopsy confirmed the semilobar HPE previously noted on US and MRI. Further, band-specific FISH revealed, in addition to SHH deletion, the presence of an inversion in the 7q translocated material on der(8). The parents' karyotypes were normal. An unexpected complex rearrangement was present in a de novo apparently balanced reciprocal translocation in a semilobar HPE. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
933.
934.
935.
Commonly, female birds use the brightly coloured patches on males to choose the best-quality mates. Coloured wing patches, however, have received little attention or have been previously related to social behaviour (as a signal to recruit conspecific individuals at feeding patches) or foraging (to flush prey) contexts, rather than to sexual selection. Here we provide evidence that in siskins (Carduelis spinus), wing patches function in mate choice. Mate-choice experiments showed that females were attracted by the size of the yellow wing stripe of the male, but not by the size of its black bib, body size, general plumage brightness or age. Experiments on birds with manipulated yellow wing stripes showed that females were sensitive to the size of this colour patch, irrespective of other male qualities. The preference of female siskins for males with larger wing patches when searching for a mate may be explained by the relationship of this trait to foraging ability, which would ensure females good parental investment from the chosen male.Communicated by W.A. Searcy 相似文献
936.
937.
Environmental Fluid Mechanics - The flow pattern within a storage zone governs the efficiency of passive scalar accumulation, spreading and homogenization. The present paper aims at characterizing... 相似文献
938.
939.
Nektarios Koutsourakis John G. Bartzis Nicolas C. Markatos 《Environmental Fluid Mechanics》2012,12(4):379-403
In this study the Reynolds-averaged Navier-Stokes computational fluid dynamics methodology is used, which has proved to be a powerful tool for the simulations of the airflow and pollutant dispersion in the atmospheric environment. The interest is focused on the urban areas and more specifically on the street canyons, several types of which are examined in order to evaluate the performance of various turbulence models, including a Reynolds-stress model and variations of the k-ε model. The results of the two-dimensional simulations are compared with measurements from a diversity of independent street canyon experimental datasets, covering a wide range of aspect ratios, free stream velocities and roughnesses. This way more general and reliable conclusions can be reached about the applicability, accuracy and ease of use of each turbulence model. In this work, the renormalization group k-ε presented better results in most cases examined, while the Reynolds-stress model did not stand up for the expectations and also exhibited convergence problems. 相似文献
940.
Displacement characteristics in animals are crucial drivers of successful movement decisions in resources acquisition, migration, and dispersal. As landscape structure is modified by human activity, mobility patterns are likely to evolve in response to habitat fragmentation. In species with complex life cycles that involve obligatory migrations between different habitats, one can predict that movement propensity would be promoted by fragmentation as long as it allows to reaching a habitat patch. Here, we compare the movement characteristics of naive toadlets sampled in populations distributed over a fragmentation gradient to test the hypothesis of a positive correlation between fragmentation and mobility levels. We studied toadlet movement in experimental arenas providing small patches of suitable conditions. We recorded the use of these patches (patch behavior) or the absence of their use (overtaking behavior). The more fragmented the original landscape, the more prone the toadlets were to combine these two behaviors, thus showing a higher motivation to explore. Moreover, the more fragmented the original landscape, the less the toadlets exhibited patch behavior. As the toadlets were reared in a common environment, the behavioral differences detected, relating to the level of fragmentation, resulted from inheritance. Our results thus illustrate that fragmentation is likely to create cross-generational transmittable variations in movement characteristics. 相似文献