首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   230篇
  免费   5篇
  国内免费   4篇
安全科学   12篇
废物处理   14篇
环保管理   10篇
综合类   75篇
基础理论   53篇
污染及防治   54篇
评价与监测   15篇
社会与环境   5篇
灾害及防治   1篇
  2023年   3篇
  2022年   3篇
  2021年   6篇
  2020年   11篇
  2019年   5篇
  2018年   9篇
  2017年   5篇
  2016年   11篇
  2015年   16篇
  2014年   11篇
  2013年   16篇
  2012年   16篇
  2011年   13篇
  2010年   12篇
  2009年   9篇
  2008年   12篇
  2007年   19篇
  2006年   13篇
  2005年   9篇
  2004年   7篇
  2003年   11篇
  2002年   7篇
  2001年   2篇
  1999年   4篇
  1998年   3篇
  1997年   1篇
  1995年   1篇
  1994年   1篇
  1993年   2篇
  1978年   1篇
排序方式: 共有239条查询结果,搜索用时 31 毫秒
71.
Regional Environmental Change - Mediterranean forests are found in the Mediterranean basin, California, the South African Cape Province, South and southwestern Australia and parts of Central Chile....  相似文献   
72.
Although particulate emissions from residential wood burning have become a subject of great scientific concern for a few years, data related to their impact on the air quality of large European urban centres are still missing. In the present study, we investigated the chemical and optical properties of fine (PM2.5) carbonaceous aerosols in Paris during the 2005 winter season in order to track the presence of wood burning emissions in such a large city. The use of a seven wavelength Aethalometer allowed us to document shortwave light absorption by brown-carbon-containing organic aerosols of biomass burning origin. In particular, a well-marked diurnal pattern of the spectral dependence of light absorption, with maxima during the night, could be observed every day of the campaign and attributed to wood burning emissions. Relatively high absorption Ångstrom exponents and WSOC/OC ratios (respectively 1.25 and 0.35 on average for the period of study) also indicated the importance of biomass burning aerosols in the Paris atmosphere in winter. Finally, a rough estimate of the contribution of wood burning carbonaceous aerosols to PM2.5 could be achieved. This contribution was found to be as high as 20 ± 10% on average at the Paris background site investigated here.  相似文献   
73.
Using Christmas Bird Count data, we analyze the annual spatio-temporal abundances of six passerine species in the upper Great Plains, US (1960-1990). This study provides new insight into how global warming could cause separation of species within present-day communities. We find that winter relative abundances of similarly-sized songbirds are differentially affected by ambient winter temperature. As such, average annual winter temperature fluctuations (i.e., severity of winter) are significantly (P < 0.05) correlated with the relative abundances of three species while the other three are not. Our conditional probability-of-occurrence analysis indicates that the abundances of the three temperature-associated species declined markedly below -4 degrees C while the abundances of the other three species fluctuated little from 8 degrees C to -16 degrees C. We conclude that even in colder climates i) the winter distributions of some, but not all, songbirds are directly or indirectly limited by temperature; and ii) these birds have dynamic abundances that can quickly respond to temperature changes.  相似文献   
74.
Phytoremediation is of great interest to remediate soil contaminated with hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and 2,4,6-trinitrotoluene (TNT). The ability of 4 agronomic plants (maize, soybean, wheat and rice) to take up these explosives and their fate in plants were investigated. Plants were grown for 42 days on soil contaminated with [(14)C]RDX or [(14)C]TNT. Then, each part was analyzed for its radioactivity content and the percentage of bound and soluble residues was determined following extractions. Extracts were analyzed by radio-HPLC. More than 80% of uptaken RDX was translocated to aerial tissues, up to 64.5 mgg(-1) of RDX. By contrast, TNT was little translocated to leaves since less than 25% of uptaken TNT was accumulated in aerial parts. Concentrations of TNT residues were 20 times lower than for RDX uptake. TNT was highly metabolized to bound residues (more than 50% of radioactivity) whereas RDX was mainly found in its parent form in aerial parts.  相似文献   
75.
76.
77.
78.
79.
80.
As a marked increase in the number of musculoskeletal disorders was noted in many industrialized countries and more specifically in companies that require the use of hand tools, the French National Research and Safety Institute (INRS) launched in 1999 a research project on the topic of integrating ergonomics into hand tool design, and more particularly to a design of a boning knife.

After a brief recall of the difficulties of integrating ergonomics at the design stage, the present paper shows how 3 design methodological tools—Functional Analysis, Quality Function Deployment and TRIZ—have been applied to the design of a boning knife. Implementation of these tools enabled us to demonstrate the extent to which they are capable ofresponding to the difficulties ofintegrating ergonomics into product design.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号