全文获取类型
收费全文 | 187篇 |
免费 | 7篇 |
国内免费 | 1篇 |
专业分类
林业 | 13篇 |
农学 | 3篇 |
8篇 | |
综合类 | 30篇 |
农作物 | 5篇 |
水产渔业 | 5篇 |
畜牧兽医 | 115篇 |
园艺 | 8篇 |
植物保护 | 8篇 |
出版年
2021年 | 2篇 |
2020年 | 2篇 |
2019年 | 3篇 |
2018年 | 7篇 |
2017年 | 4篇 |
2016年 | 3篇 |
2015年 | 2篇 |
2014年 | 2篇 |
2013年 | 10篇 |
2012年 | 2篇 |
2011年 | 10篇 |
2010年 | 6篇 |
2009年 | 4篇 |
2008年 | 8篇 |
2007年 | 4篇 |
2006年 | 6篇 |
2005年 | 7篇 |
2004年 | 3篇 |
2003年 | 5篇 |
2001年 | 4篇 |
2000年 | 5篇 |
1999年 | 4篇 |
1998年 | 2篇 |
1997年 | 4篇 |
1996年 | 3篇 |
1995年 | 5篇 |
1994年 | 3篇 |
1992年 | 2篇 |
1991年 | 4篇 |
1990年 | 8篇 |
1989年 | 5篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1981年 | 3篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1976年 | 2篇 |
1975年 | 3篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1970年 | 2篇 |
1969年 | 3篇 |
1968年 | 2篇 |
1967年 | 2篇 |
1921年 | 2篇 |
1913年 | 1篇 |
排序方式: 共有195条查询结果,搜索用时 46 毫秒
11.
Graves WR 《Tree physiology》1992,11(2):205-211
The morphology and hydraulic conductivity of root systems of Gleditsia triacanthos L. var. inermis Willd. (honey locust) grown hydroponically in sand and solution cultures were compared. Total root system length was similar in the two cultures. However, root systems grown in solution had longer primary roots, fewer lateral roots and root hairs, and a greater distance between the tip of the primary root and the junction of the youngest secondary root and the primary root than root systems grown in sand. Hydraulic conductivities of root systems grown hydroponically for 21 or 35 days in sand or solution culture were similar. These findings show that different methods of hydroponic culture can affect root morphology without altering root resistance to water transport. 相似文献
12.
13.
14.
Z H Huang S Graves L Stewart J Banks B Dwyer 《Comparative immunology, microbiology and infectious diseases》1990,13(3):119-125
New endemic areas of spotted fever-like rickettsial disease have been found in south-eastern Australia (Gippsland, Victoria and Flinders Island, Tasmania). The rickettsia responsible is currently unknown although it may be Rickettsia australis. To investigate serological evidence of rickettsial exposure in various wild animal species, a competitive ELISA was developed which detected antibodies to R. australis. It was based on inhibition of an indirect ELISA detecting antibody to R. australis in guinea pig sera. Pre- and post-infection sera from 2 dogs, 2 rabbits, 5 mice and 6 rats, experimentally infected with R. australis, were tested by competitive ELISA. The results showed that all pre-infection sera were negative and all post-infection sera positive for antibody to R. australis. To test the utility of the competitive ELISA for detecting natural rickettsial infection in non-laboratory animals, 51 dog sera, negative for rickettsial antibody by immunofluorescence (IF) and 20 IF positive dog sera (collected from various locations on the east coast of Australia) were tested. Compared to the IF test the competitive ELISA was 90% sensitive and 96% specific. This new test has potential for detecting antibody to R. australis in the sera of different wild animal species. 相似文献
15.
16.
The counterdiffusion of gases across a composite layer can lead to supersaturation and development of bubbles within the layer. A physicochemical model has been derived to predict the extent of such supersaturation; experiments with inert liquid layers confirm predictions. These findings explain the evolution of cutaneous lesions observed in man during simulated deep-sea dives and the cutaneous lesions and intravascular bubbles experimentally induced in pigs by exchanging certain inert gases across the skin. The phenomena associated with counterdiffusion have widespread physical and biological implications. 相似文献
17.
Graves AH 《Science (New York, N.Y.)》1918,48(1252):652-653
18.
Graves HB 《Science (New York, N.Y.)》1973,182(4115):937-939
19.
20.
Graves HS 《Science (New York, N.Y.)》1915,41(1047):117-127