全文获取类型
收费全文 | 305721篇 |
免费 | 16929篇 |
国内免费 | 666篇 |
专业分类
林业 | 24459篇 |
农学 | 14199篇 |
基础科学 | 3011篇 |
45935篇 | |
综合类 | 41724篇 |
农作物 | 17556篇 |
水产渔业 | 17874篇 |
畜牧兽医 | 126796篇 |
园艺 | 6519篇 |
植物保护 | 25243篇 |
出版年
2019年 | 3759篇 |
2018年 | 4260篇 |
2017年 | 4698篇 |
2016年 | 5011篇 |
2015年 | 4471篇 |
2014年 | 5841篇 |
2013年 | 16517篇 |
2012年 | 7582篇 |
2011年 | 9861篇 |
2010年 | 7884篇 |
2009年 | 8322篇 |
2008年 | 9152篇 |
2007年 | 8260篇 |
2006年 | 8752篇 |
2005年 | 7953篇 |
2004年 | 7769篇 |
2003年 | 7525篇 |
2002年 | 6857篇 |
2001年 | 7934篇 |
2000年 | 7608篇 |
1999年 | 6659篇 |
1998年 | 4339篇 |
1997年 | 4394篇 |
1996年 | 4121篇 |
1995年 | 4808篇 |
1994年 | 4240篇 |
1993年 | 3951篇 |
1992年 | 5609篇 |
1991年 | 5808篇 |
1990年 | 5535篇 |
1989年 | 5570篇 |
1988年 | 4963篇 |
1987年 | 5106篇 |
1986年 | 5210篇 |
1985年 | 5316篇 |
1984年 | 4654篇 |
1983年 | 4388篇 |
1982年 | 3384篇 |
1981年 | 3247篇 |
1980年 | 3152篇 |
1979年 | 4075篇 |
1978年 | 3575篇 |
1977年 | 3150篇 |
1976年 | 3018篇 |
1975年 | 2966篇 |
1974年 | 3405篇 |
1973年 | 3460篇 |
1972年 | 3210篇 |
1971年 | 3159篇 |
1970年 | 3029篇 |
排序方式: 共有10000条查询结果,搜索用时 8 毫秒
951.
952.
953.
954.
Holden C 《Science (New York, N.Y.)》1985,230(4730):1146
955.
Pemphigus foliaceus of the footpads in three dogs 总被引:1,自引:0,他引:1
P J Ihrke A A Stannard A A Ardans C E Griffin A J Kallet 《Journal of the American Veterinary Medical Association》1985,186(1):67-69
Severe hyperkeratinization and villous hypertrophy of the footpads were seen in 3 middle-aged dogs. Peeling, fissuring, swelling, and ulcerations were noted on the margins of severely affected pads. Pain was evident in palpation and ambulation. Lesions were compatible with the traditional diagnosis of "hard pad disease". Histopathologic findings were diagnostic for canine pemphigus foliaceus in all 3 dogs, and direct immunofluorescence in an intercellular pattern was seen in both dogs that were tested. All 3 dogs responded to immunosuppressive dosages of corticosteroids. 相似文献
956.
Assaf R Turgeon D St-Jacques C Hamelin C 《The Canadian veterinary journal. La revue veterinaire canadienne》1985,26(7):209-211
For the first time in Quebec, a type 1 canine adenovirus was isolated in cell culture and typed by restriction endonuclease analysis. This virus originated from the internal organs of a young dog killed by a severe respiratory disease without showing any sign of hepatitis. 相似文献
957.
958.
Bussanich MN Rootman J Kumi C Gudauskas G 《The Canadian veterinary journal. La revue veterinaire canadienne》1985,26(9):263-266
The ocular absorption, elimination and toxicity of 12.5 mg of methotrexate in 0.5 cc administered subconjunctivally was studied in the dog. The purpose of this study was to establish ocular pharmacokinetics for treatment of intraocular tumours in dogs. Drug levels were measured in ocular compartments, and serum at 1,2,4,6,8 and 12 hours respectively. Tumoricidal concentrations of the drug were attained in the anterior chambers of the injected eyes up to and including six hours postinjection. Consistent signs of toxicity were anorexia, vomiting, weight loss and leukopenia. Local ocular toxicity following subconjunctival injection was minimal conjunctival hyperemia lasting up to 48 hours. 相似文献
959.
Hurtig MB Farrow CS Fretz PB 《The Canadian veterinary journal. La revue veterinaire canadienne》1985,26(6):177-180
The radial carpal and intermediate carpal bones were found to be fused in a four year old Quarterhorse stallion having a subtle forelimb lameness. Clinical examination, diagnostic local anesthesia, radiography and arthroscopy were used to arrive at the diagnosis. A cause could not be established, although perinatal deformation of cartilagenous carpal bone templates is suspected. A similar case of carpal bone fusion was found among carpi collected for an anatomical study, indicating this condition may be more common than expected. Clinicians should carefully evaluate the flexed lateral view of the carpus for proximal movement of the intermediate and ulnar carpal bones in young horses presented for carpal lameness. The significance of this condition will remain uncertain until its incidence and relationship to lameness are better defined. 相似文献
960.
Evaluation of a Killed Vaccine Against Porcine Pleuropneumonia Due to Haemophilus pleuropneumoniae 总被引:20,自引:2,他引:18
Higgins R Larivière S Mittal KR Martineau GP Rousseau P Cameron J 《The Canadian veterinary journal. La revue veterinaire canadienne》1985,26(2):86-89
A bacterin containing serotypes 1 and 5 of Haemophilus pleuropneumoniae was developed for the prevention and the control of porcine pleuropneumonia. It was injected intramuscularly into three groups of ten piglets, the first group with one dose, the second one with two doses and the third one with three doses at two-week intervals. Another group of ten piglets did not receive the vaccine. All the piglets were then challenged by an aerosol of mixed suspensions of H. pleuropneumoniae serotypes 1 and 5. Two and three injections of vaccine completely prevented mortality, whereas half of the control piglets and of those receiving only one dose of vaccine died. All surviving piglets, both control and vaccinated, had severe signs of respiratory disease for at least 36 hours after exposure to challenge. Moreover, vaccination did not induce the production of antibodies at high titers. Local reactions were not noted after vaccination and at postmortem; ten weeks after the challenge, there were no signs of abscess formation or induration. 相似文献