全文获取类型
收费全文 | 452篇 |
免费 | 8篇 |
国内免费 | 1篇 |
专业分类
安全科学 | 18篇 |
废物处理 | 10篇 |
环保管理 | 58篇 |
综合类 | 137篇 |
基础理论 | 120篇 |
环境理论 | 2篇 |
污染及防治 | 74篇 |
评价与监测 | 21篇 |
社会与环境 | 15篇 |
灾害及防治 | 6篇 |
出版年
2020年 | 5篇 |
2019年 | 4篇 |
2018年 | 8篇 |
2017年 | 6篇 |
2016年 | 15篇 |
2015年 | 6篇 |
2013年 | 27篇 |
2012年 | 17篇 |
2011年 | 19篇 |
2010年 | 11篇 |
2009年 | 17篇 |
2008年 | 16篇 |
2007年 | 19篇 |
2006年 | 23篇 |
2005年 | 15篇 |
2004年 | 10篇 |
2003年 | 7篇 |
2002年 | 8篇 |
2001年 | 5篇 |
2000年 | 6篇 |
1999年 | 10篇 |
1998年 | 5篇 |
1997年 | 5篇 |
1996年 | 5篇 |
1992年 | 6篇 |
1991年 | 4篇 |
1989年 | 4篇 |
1985年 | 7篇 |
1984年 | 5篇 |
1983年 | 8篇 |
1982年 | 6篇 |
1981年 | 5篇 |
1978年 | 5篇 |
1976年 | 5篇 |
1974年 | 7篇 |
1971年 | 4篇 |
1967年 | 6篇 |
1965年 | 4篇 |
1964年 | 4篇 |
1961年 | 7篇 |
1960年 | 4篇 |
1957年 | 4篇 |
1956年 | 4篇 |
1948年 | 4篇 |
1940年 | 3篇 |
1937年 | 3篇 |
1928年 | 3篇 |
1920年 | 5篇 |
1916年 | 3篇 |
1913年 | 3篇 |
排序方式: 共有461条查询结果,搜索用时 15 毫秒
71.
P. OKeefe C. Meyer D. Hilker K. Aldous B. Jelus-Tyror K. Dillon R. Donnelly E. Horn R. Sloan 《Chemosphere》1983,12(3):325-332
In fish samples from Lake Ontario and Lake Huron 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) was found at concentrations from 2 to 162 pg/g (ppt) and from 2.5 to 29 ppt respectively. Fish from the other Great Lakes (Lake Superior, Lake Michigan and Lake Erie) generally had no detectable signals for TCDD although a few samples had < 3 ppt. 相似文献
72.
73.
74.
Fr. Meyer 《Die Naturwissenschaften》1926,14(23):533-538
75.
76.
77.
Hans Horst Meyer 《Die Naturwissenschaften》1934,22(36):598-601
78.
79.
Kurt H. Meyer 《Die Naturwissenschaften》1927,15(6):129-134
80.
The giant clam Tridacna crocea harbors in the mantle tissue symbiotic microalgae commonly called zooxanthellae. Isolated zooxanthellae release glycerol
into the medium in the presence of mantle tissue homogenate (MH), but it is not clear whether the cells do so in situ. In
order to determine the photosynthetic products released by zooxanthellae in the mantle of the giant clam we traced photosynthetic
fixation products from 13C- and 14C-bicarbonate both in the clam and in isolated zooxanthellae (IZ) in the presence or absence of MH. After 15 min incubation
in the absence of MH the IZ released less than 0.6% of the fixed labeled carbon, mainly as glucose. The major intracellular
photosynthates were neutral lipids, which constituted 20 to 40% of the total extractable 14C. In the presence of MH, the IZ released up to 5.6% of the total fixed 14C, mostly as glycerol, and the major intracellular photosynthate was glucose. In an intact clam incubated in sea water containing
14C-bicarbonate, 46 to 80% of the fixed 14C was translocated from the zooxanthellae to the host tissues. Most of the 14C in the hemolymph, in the isolated zooxanthellae and in intact mantle tissue (containing zooxanthellae) was recovered as
glucose. No 14C-glycerol was detected in the mantle after 1 to 30 min incubation, and, even after 60 min, far less 14C-glycerol was synthesized than by IZ in the presence of MH. The possibility that in clam tissue glycerol is converted to
glucose was examined by tracing the labeled carbon from 14C-glycerol injected into the adductor muscle. After 5 min incubation, no labeled glucose was found in the hemolymph, but after
60 min, some 20% was found as glucose. Thin slices containing zooxanthellae, cut from the surface of the mantle, fixed inorganic
carbon supplied as NaH14CO3 in the medium and mainly released 14C-glucose. The addition of MH to the surrounding medium did not affect the release rate or form of release product. When the
slices were cut into smaller pieces, however, the ratio of glycerol to glucose in the release product increased. These results
indicate that in the presence of MH the metabolism of isolated zooxan- thellae was different from that of zooxanthellae in
the mantle. In the presence of MH, isolated zooxanthellae release mostly glycerol, whereas in the mantle they release glucose.
Received: 18 February 1998 / Accepted: 4 December 1998 相似文献