全文获取类型
收费全文 | 306篇 |
免费 | 14篇 |
专业分类
林业 | 7篇 |
农学 | 6篇 |
31篇 | |
综合类 | 73篇 |
农作物 | 5篇 |
水产渔业 | 4篇 |
畜牧兽医 | 182篇 |
园艺 | 4篇 |
植物保护 | 8篇 |
出版年
2023年 | 3篇 |
2020年 | 11篇 |
2019年 | 3篇 |
2018年 | 4篇 |
2017年 | 7篇 |
2016年 | 3篇 |
2015年 | 6篇 |
2014年 | 11篇 |
2013年 | 10篇 |
2012年 | 11篇 |
2011年 | 11篇 |
2010年 | 12篇 |
2009年 | 3篇 |
2008年 | 7篇 |
2007年 | 8篇 |
2006年 | 8篇 |
2005年 | 13篇 |
2004年 | 8篇 |
2003年 | 17篇 |
2002年 | 11篇 |
2001年 | 7篇 |
1999年 | 8篇 |
1998年 | 7篇 |
1997年 | 5篇 |
1996年 | 11篇 |
1995年 | 2篇 |
1994年 | 4篇 |
1993年 | 5篇 |
1992年 | 8篇 |
1991年 | 8篇 |
1990年 | 11篇 |
1988年 | 2篇 |
1986年 | 7篇 |
1985年 | 4篇 |
1984年 | 4篇 |
1983年 | 4篇 |
1982年 | 2篇 |
1981年 | 5篇 |
1980年 | 3篇 |
1979年 | 2篇 |
1972年 | 2篇 |
1970年 | 3篇 |
1967年 | 3篇 |
1966年 | 3篇 |
1910年 | 2篇 |
1892年 | 1篇 |
1888年 | 1篇 |
1885年 | 1篇 |
1884年 | 8篇 |
1883年 | 6篇 |
排序方式: 共有320条查询结果,搜索用时 0 毫秒
21.
Fecal samples were collected from 144 llamas, Lama glama, on four premises in northern Colorado and southern Wyoming. Feces were examined for the presence of coccidial oocysts; Eimeria alpacae was found in 55.6%, Eimeria lamae in 67.3% and Eimeria macusaniensis in 1.4% of the samples. An adult female llama was found to be infected with Eimeria macusaniensis at necropsy. This is the first report of these species of coccidia in the llama. 相似文献
22.
23.
24.
25.
B. T. L. Bell G. J. Baker L. C. Abbott J. H. Foreman S. K. Kneller 《Anatomia, histologia, embryologia》1995,24(1):39-45
The vascular anatomy of the ethmoidal area in six normal horses and two normal ponies was studied using vascularcorrosion casts. The major arterial supply to the ethmoidal area sterns from an intracranial source. The internal and external ethmoidal arteries anastomose on the rostral intracranial surface of the cribriform plate to form the arterial ethmoidal rete which arborizes and passes through the perforations of the cribriform plate to supply the ethmoid labyrinth. A minor arterial supply to the ventral portion of the ethmoid labyrinth sterns from a small caudal nasal branch of the sphenopalatine artery. Multiple parallel venules drain the ethmoid labyrinth rostrally to its apex then join the venous drainage from the surrounding sinuses. 相似文献
26.
27.
28.
Huntington's disease: two families with differing clinical features show linkage to the G8 probe 总被引:8,自引:0,他引:8
S E Folstein J A Phillips D A Meyers G A Chase M H Abbott M L Franz P G Waber H H Kazazian P M Conneally W Hobbs 《Science (New York, N.Y.)》1985,229(4715):776-779
To test the hypothesis that interfamily variability in Huntington's Disease (HD) is due to mutation at different loci, linkage analysis was undertaken in two large HD kindreds that differed in ethnicity, age-at-onset, and neurologic and psychiatric features. Both families showed linkage of the HD locus to the G8 probe. Several recombinants were documented in each family, and the best estimate of the recombination fraction for the two families was 6 percent with a 95 percent confidence interval of 0 to 12 percent. Although the data support the existence of a single HD locus, use of the G8 probe for presymptomatic testing in these kindreds would have resulted in a 12 percent error rate in genotype assignment at the HD locus. 相似文献
29.
ZF Ren ZP Huang JW Xu JH Wang P Bush MP Siegal PN Provencio 《Science (New York, N.Y.)》1998,282(5391):1105-1107
Free-standing aligned carbon nanotubes have previously been grown above 700 degreesC on mesoporous silica embedded with iron nanoparticles. Here, carbon nanotubes aligned over areas up to several square centimeters were grown on nickel-coated glass below 666 degreesC by plasma-enhanced hot filament chemical vapor deposition. Acetylene gas was used as the carbon source and ammonia gas was used as a catalyst and dilution gas. Nanotubes with controllable diameters from 20 to 400 nanometers and lengths from 0. 1 to 50 micrometers were obtained. Using this method, large panels of aligned carbon nanotubes can be made under conditions that are suitable for device fabrication. 相似文献
30.