全文获取类型
收费全文 | 2884篇 |
免费 | 194篇 |
国内免费 | 4篇 |
专业分类
林业 | 198篇 |
农学 | 70篇 |
基础科学 | 22篇 |
486篇 | |
综合类 | 701篇 |
农作物 | 62篇 |
水产渔业 | 241篇 |
畜牧兽医 | 1018篇 |
园艺 | 90篇 |
植物保护 | 194篇 |
出版年
2023年 | 20篇 |
2022年 | 23篇 |
2021年 | 66篇 |
2020年 | 77篇 |
2019年 | 91篇 |
2018年 | 81篇 |
2017年 | 77篇 |
2016年 | 89篇 |
2015年 | 71篇 |
2014年 | 79篇 |
2013年 | 108篇 |
2012年 | 192篇 |
2011年 | 225篇 |
2010年 | 147篇 |
2009年 | 97篇 |
2008年 | 224篇 |
2007年 | 214篇 |
2006年 | 198篇 |
2005年 | 191篇 |
2004年 | 194篇 |
2003年 | 184篇 |
2002年 | 177篇 |
2001年 | 31篇 |
2000年 | 21篇 |
1999年 | 20篇 |
1998年 | 9篇 |
1997年 | 7篇 |
1996年 | 9篇 |
1995年 | 14篇 |
1994年 | 12篇 |
1993年 | 9篇 |
1992年 | 5篇 |
1991年 | 11篇 |
1990年 | 6篇 |
1989年 | 10篇 |
1988年 | 6篇 |
1987年 | 10篇 |
1986年 | 7篇 |
1985年 | 8篇 |
1984年 | 4篇 |
1982年 | 5篇 |
1981年 | 3篇 |
1980年 | 6篇 |
1976年 | 5篇 |
1974年 | 8篇 |
1973年 | 3篇 |
1970年 | 3篇 |
1968年 | 2篇 |
1961年 | 2篇 |
1957年 | 2篇 |
排序方式: 共有3082条查询结果,搜索用时 187 毫秒
11.
12.
13.
14.
15.
Catherine Bouchard Erin Leonard Jules Konan Koffi Yann Pelcat Andrew Peregrine Neil Chilton Kateryn Rochon Tim Lysyk L. Robbin Lindsay Nicholas Hume Ogden 《The Canadian veterinary journal. La revue veterinaire canadienne》2015,56(7):693-699
There is an increasing risk of Lyme disease in Canada due to range expansion of the tick vector, Ixodes scapularis. The objectives of this article are to i) raise public awareness with the help of veterinarians on the emerging and expanding risk of Lyme disease across Canada, ii) review the key clinical features of Lyme disease in dogs, and iii) provide recommendations for veterinarians on the management of Lyme disease in dogs. 相似文献
16.
Lana A. Gyan Chad D. Paetsch Murray D. Jelinski Andrew L. Allen 《The Canadian veterinary journal. La revue veterinaire canadienne》2015,56(11):1134-1139
Gross and histologic postmortem studies were performed on the hind feet of feedlot cattle that had, or were free from, lesions of toe tip necrosis. The hind feet of feedlot cattle were collected by 3 veterinary feedlot practices in southern Alberta, Canada. Three studies of these feet were conducted: i) prediction of disease based on the presence or absence of apical white line separation, ii) gross assessment of the distribution and severity of lesions within affected claws, and iii) microscopic evaluation of the distal phalanx and surrounding soft tissues of affected claws. Prediction of toe tip necrosis based on the presence of apical white line separation was statistically significant (P < 0.0001). This, combined with a pattern of lesions indicative of an ascending infection of the distal phalanx and the absence of other lesions, suggests that the pathogenesis involves bacterial infection originating from the most distal aspect of the toe, at the apical white line. 相似文献
17.
18.
19.
Kamran Haq Sarah K. Wootton Neda Barjesteh Serguei Golovan Andrew Bendall Shayan Sharif 《Canadian journal of veterinary research》2015,79(1):1-7
Interferon (IFN)-γ has been shown to be associated with immunity to Marek’s disease virus (MDV). The overall objective of this study was to investigate the causal relationship between IFN-γ and vaccine-conferred immunity against MDV in chickens. To this end, 3 small interfering RNAs (siRNAs) targeting chicken IFN-γ, which had previously been shown to reduce IFN-γ expression in vitro, and a control siRNA were selected to generate recombinant avian adeno-associated virus (rAAAV) expressing short-hairpin small interfering RNAs (shRNAs). An MDV challenge trial was then conducted: chickens were vaccinated with herpesvirus of turkey (HVT), administered the rAAAV expressing shRNA, and then challenged with MDV. Tumors were observed in 4 out of 10 birds that were vaccinated with HVT and challenged but did not receive any rAAAV, 5 out of 9 birds that were administered the rAAAV containing IFN-γ shRNA, and 2 out of 10 birds that were administered a control enhanced green fluorescent protein siRNA. There was no significant difference in MDV genome load in the feather follicle epithelium of the birds that were cotreated with the vaccine and the rAAAV compared with the vaccinated MDV-infected birds. These results suggest that AAAV-based vectors can be used for the delivery of shRNA into chicken cells. However, administration of the rAAAV expressing shRNA targeting chicken IFN-γ did not seem to fully abrogate vaccine-induced protection. 相似文献