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   270篇
  免费   0篇
安全科学   1篇
废物处理   6篇
环保管理   4篇
综合类   196篇
基础理论   22篇
污染及防治   27篇
评价与监测   12篇
社会与环境   2篇
  2013年   8篇
  2011年   3篇
  2009年   11篇
  2008年   3篇
  2007年   5篇
  2006年   5篇
  2005年   3篇
  2003年   3篇
  2002年   3篇
  2001年   3篇
  1999年   4篇
  1997年   4篇
  1996年   3篇
  1985年   5篇
  1984年   3篇
  1968年   3篇
  1967年   4篇
  1966年   6篇
  1965年   6篇
  1964年   5篇
  1963年   4篇
  1962年   6篇
  1961年   8篇
  1960年   6篇
  1959年   5篇
  1958年   14篇
  1957年   6篇
  1955年   5篇
  1954年   4篇
  1953年   3篇
  1952年   6篇
  1951年   5篇
  1950年   3篇
  1943年   4篇
  1940年   2篇
  1938年   3篇
  1937年   7篇
  1936年   6篇
  1935年   6篇
  1934年   4篇
  1933年   3篇
  1932年   2篇
  1931年   3篇
  1930年   2篇
  1928年   5篇
  1927年   2篇
  1926年   3篇
  1923年   4篇
  1922年   5篇
  1921年   3篇
排序方式: 共有270条查询结果,搜索用时 31 毫秒
221.
Exposures to airborne irritants such as O3, NO2, SO2 and H2SO4 can produce measurable changes in a variety of pulmonary functions such as respiratory mechanics, pulmonary gas exchange, mucociliary particle clearance, and airway permeability. The most commonly measured indices of pulmonary function are those obtained by analyzing flows and volumes during a maximal forced expiratory maneuver, because they can be obtained readily in both laboratory and field studies in humans. Other functional measures are essentially limited to laboratory studies on relatively small populations of humans, or on experimental animals. Interpretation of respiratory function changes in relation to exposures to airborne irritants is complicated by the large interindividual variability in baseline function and responsiveness, the superposition of both the transient effects of recent acute exposure and the cumulative effects of chronic exposure at any given measurement, and the inherent day-to-day variability of effort dependent indices. Furthermore, community exposures occur as mixtures. Each of several components may affect the same functions, but with different time scales, and may affect different segments of the population to different degrees. The greatest uncertainties lie in the significance of transient and apparently reversible effects, and their contribution, if any, to permanent functional changes. Use of animal models to study the role of transient changes in function on the development of permanent changes is illustrated in terms of the effects of H2SO4 on particle clearance function.  相似文献   
222.
223.
224.
Sixty home made wine and sixty-four grape samples were collectedfrom five territories in Jordan, where grapes and wine aremostly producted. The collected samples were analyzed for themost used organochlorine pesticides (OCP) and organophosphorouspesticides (OPP) in Jordan, as well as for four heavy metals(Ni, Cu, Zn and Pb). The results showed that OCPs residues weredetected in 73% of the wine samples but no OPPs residue weredetected which is due to generally shorter half life of thelater pesticide. Grapes showed higher incident of contaminationthan wine, however, OCPs and OPPs with both short and longhalf-lives were detected. The OPPs were detected in only8.3% of the analyzed grape samples. Heavy metals showed higher valuesin grapes than in the wine samples and it was attributed toremoval of solids during wine preparation processes or throughcontamination of wine during storage. Most of the samples werebelow toxic limit.  相似文献   
225.
Thousands of chemicals are on the market, but only in a few exceptional cases is it known where these chemicals remain in the environment and what effects they are able toexert in correlation to their environmental concentration. In addition to monitoring the actual concentrations of chemicals in the environment, it is necessary to establish an environmental specimen banking program which will, in the future, make possible the retrospective monitoring of chemicals. The feasibility of such a program is being studied in a joint U.S.-German pilot project. The German project is described here, including its organizational structure, technical and scientific considerations, and methods of specimen selection.  相似文献   
226.
227.
228.
229.
230.
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