全文获取类型
收费全文 | 226篇 |
免费 | 0篇 |
专业分类
安全科学 | 1篇 |
废物处理 | 6篇 |
环保管理 | 4篇 |
综合类 | 162篇 |
基础理论 | 21篇 |
污染及防治 | 19篇 |
评价与监测 | 12篇 |
社会与环境 | 1篇 |
出版年
2013年 | 4篇 |
2011年 | 3篇 |
2009年 | 11篇 |
2007年 | 5篇 |
2006年 | 5篇 |
2005年 | 3篇 |
2003年 | 2篇 |
2002年 | 3篇 |
2001年 | 3篇 |
1999年 | 4篇 |
1997年 | 4篇 |
1996年 | 3篇 |
1991年 | 2篇 |
1985年 | 3篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1977年 | 2篇 |
1969年 | 2篇 |
1967年 | 3篇 |
1966年 | 5篇 |
1965年 | 6篇 |
1964年 | 5篇 |
1963年 | 4篇 |
1962年 | 5篇 |
1961年 | 8篇 |
1960年 | 6篇 |
1959年 | 4篇 |
1958年 | 12篇 |
1957年 | 6篇 |
1956年 | 2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 |
1949年 | 2篇 |
1943年 | 4篇 |
1940年 | 2篇 |
1938年 | 3篇 |
1935年 | 2篇 |
1933年 | 2篇 |
1932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226条查询结果,搜索用时 31 毫秒
71.
72.
The Science of Nature - 相似文献
73.
74.
75.
Friedrich Schenck 《Die Naturwissenschaften》1937,25(10):159-159
76.
Richard K. Laing Burkhard Wickert Rainer Friedrich 《Journal of the Air & Waste Management Association (1995)》2013,63(12):1175-1182
ABSTRACT For the evaluation of air quality improvement strategies, emission data in high temporal and spatial resolution is necessary, including all emission sources and all relevant pollutant species. Computer aided models are usually used to generate this emission data because it is not possible to obtain measurements from all sources, and, furthermore, a large amount of data has to be handled. For the development of emission modeling systems, a software tool called CAREAIR has been created. The intention of this paper is to introduce CAREAIR to the international community dealing with emission inventories and air quality improvement strategies. CAREAIR is not just a single emission model but a flexible modeling toolbox. The database contains data and formulas for data manipulation, which is performed by using a set of flexible operators with different specifications. The emission calculation is carried out by combining several data manipulation operators. The CAREAIR modeling toolbox allows model implementation for the calculation of emissions from different pollutants in a high spatial and temporal resolution. The application of CAREAIR within various investigation projects in Germany, Europe, and Nigeria shows that CAREAIR is an appropriate instrument for the development of flexible emission models by meeting the various demands of these projects. The function and the data structures of this modeling toolbox are described and, towards the end of the paper, an example of an emission calculation with CAREAIR is given. 相似文献
77.
78.
Passive vapor monitoring of underground storage tanks (USTs) containing volatile hydrocarbons at locations external to the tank (an external system) is touted as a fast and effective method of leak detection. However, major gaps remain in our knowledge of the physical processes that relate a measured vapor concentration to the leak rate, thus making network design according to a quantitative design criterion nearly impossible, and differentiation between surface spills and a leaking UST requires certain levels of sophistication in the leak detection system and in the analysis that are not usually available. Heavier-than-air vapors from the constituents of stored hydrocarbons could result in a density-driven convective propagation component that complicates the design of leak detection systems, and finally, detection times are highly sensitive to concentration detection threshold levels set by the system. The use of inadequate systems and analyses can lead to either wasted efforts or excessive subsurface contamination. This paper discusses the physical processes involved, explores the above aspects of external passive vapor leak detection design, and suggests some alternatives as they pertain to gasoline service stations. 相似文献
79.
The investigation of 5547 prenatal diagnoses showed 31 unexpected structural chromosome rearrangements. These included 3 Robertsonian translocations, 14 reciprocal translocations and 14 inversions. A11 were balanced, including 5 de novo rearrangements. In 3 of these cases an induced abortion was performed and in 2 cases children without detectable malformations were delivered. 相似文献
80.