全文获取类型
收费全文 | 1211篇 |
免费 | 47篇 |
国内免费 | 1篇 |
专业分类
林业 | 69篇 |
农学 | 38篇 |
基础科学 | 10篇 |
181篇 | |
综合类 | 166篇 |
农作物 | 102篇 |
水产渔业 | 115篇 |
畜牧兽医 | 487篇 |
园艺 | 29篇 |
植物保护 | 62篇 |
出版年
2023年 | 9篇 |
2022年 | 8篇 |
2021年 | 8篇 |
2020年 | 19篇 |
2019年 | 26篇 |
2018年 | 26篇 |
2017年 | 20篇 |
2016年 | 22篇 |
2015年 | 17篇 |
2014年 | 29篇 |
2013年 | 46篇 |
2012年 | 44篇 |
2011年 | 82篇 |
2010年 | 54篇 |
2009年 | 51篇 |
2008年 | 84篇 |
2007年 | 74篇 |
2006年 | 81篇 |
2005年 | 68篇 |
2004年 | 65篇 |
2003年 | 63篇 |
2002年 | 57篇 |
2001年 | 4篇 |
2000年 | 6篇 |
1999年 | 5篇 |
1998年 | 17篇 |
1997年 | 13篇 |
1996年 | 12篇 |
1995年 | 7篇 |
1994年 | 9篇 |
1993年 | 16篇 |
1992年 | 9篇 |
1991年 | 20篇 |
1990年 | 14篇 |
1989年 | 15篇 |
1988年 | 11篇 |
1987年 | 11篇 |
1986年 | 9篇 |
1985年 | 9篇 |
1984年 | 12篇 |
1983年 | 9篇 |
1982年 | 4篇 |
1981年 | 4篇 |
1980年 | 9篇 |
1979年 | 9篇 |
1978年 | 13篇 |
1976年 | 5篇 |
1975年 | 4篇 |
1974年 | 5篇 |
1966年 | 6篇 |
排序方式: 共有1259条查询结果,搜索用时 15 毫秒
1.
Holly L. Jordan DVM Carol B. Grindem DVM PhD Edward B. Breitschwerdt DVM 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》1993,7(5):261-265
The prevalence of feline thrombocytopenia (<200,000 platelets/L) at North Carolina State University, College of Veterinary Medicine Teaching Hospital, from January 1985 to March 1990, was 1.2% (41/3300). Cats were divided into six categories based on clinical diagnoses: 29% (12/41) had infectious disease, 20% (8/41) had neoplasia, 7% (3/41) had cardiac disease, 2% (1/41) had primary immune-mediated disease, 22% (9/41) had multiple diseases, and 20% (8/41) had disorders of unknown etiology. The mean platelet count for all thrombocytopenic cats was 52,000/μL ± 46,000/μL (1 SD) with a range of 1000–190,000/μL. No significant differences were found between groups with respect to platelet count, packed cell volume, or white blood cell count, though anemia and leukopenia were common among the cats as a whole. Bleeding disorders (hemorrhage or thrombosis) were observed in 29% (12/41) of thrombocytopenic cats and were more likely to be associated with neoplasia, cardiac disease, and platelet counts less than or equal to 30,000/μL. Disseminated intravascular coagulopathy was diagnosed in 12% (5/41) of the cats. Infections and/or neoplasia affecting the bone marrow were the most common diseases associated with thrombocytopenia. Feline leukemia virus and myeloproliferative neoplasia accounted for approximately 44% (18/41) of the specific diagnoses in thrombocytopenic cats. (Journal of Veterinary Internal Medicine 1993; 7:261–265. Copyright © 1993 by the American College of Veterinary Internal Medicine.) 相似文献
2.
人们认为猪圆环病毒2型(PCV2)是发生断奶仔猪多系统衰竭综合征的一个必要因素.目前断奶仔猪多系统衰竭综合征在欧洲称作猪圆环病毒病(PCVD),在北美称作猪圆环病毒相关疾病(PCVAD). 相似文献
4.
Sidaway BK McLaughlin RM Elder SH Boyle CR Silverman EB 《American journal of veterinary research》2004,65(9):1216-1222
OBJECTIVE: To objectively evaluate the effect of transecting the tendon of the biceps brachii muscle (BBT), tendon of the infraspinatus muscle (IFS), or medial glenohumeral ligament (MGHL) on shoulder joint stability in canine cadavers. SAMPLE POPULATION: 81 forelimbs from mature dogs. PROCEDURE: Cadaver forelimbs were placed in a testing frame and axially preloaded with 4 kg of weight. Shoulder joint stability was tested in neutral joint position, flexion, and extension before and after transection of the BBT (n = 37), IFS (37), or MGHL (7). Humeral translation relative to the glenoid was induced by applying a 3-kg load in each of 3 directions (cranial, lateral, and medial) and quantitatively measured by use of an electromagnetic motion tracking system. Peak translational data were compared in each joint position before and after transection of the BBT, IFS, or MGHL. RESULTS: When tested in neutral position, the cranial, lateral, and medial translation of the humerus was significantly increased after BBT transection. In the flexed position, translation of the humerus in the cranial and lateral directions was significantly increased after BBT transection. In the extended position, the medial translation of the humerus was significantly increased after BBT transection. Complete medial luxation of all humeral heads occurred following transection of the MGHL. CONCLUSIONS AND CLINICAL RELEVANCE: The BBT contributes to passive shoulder joint stability in dogs, particularly in the neutral and flexed positions. It also provides medial stability during shoulder joint extension. Complete luxation of the joint occurs when the MGHL is transected. 相似文献
5.
6.
Lugo J Harkema JR deFeijter-Rupp H Bartner L Boruta D Robinson NE 《Veterinary journal (London, England : 1997)》2006,172(2):293-301
This study was performed to determine if a peripheral sample of lung from the site where biopsy is conducted is representative of the rest of the lung and to investigate the relationship between airway inflammation and intraepithelial mucous production in the peripheral airways. Lung parenchyma samples were collected from five different regions of the lung in five control and five heaves-affected horses. Horse groups were defined by clinical response to stabling. Tissue sections were used for semi-quantitative scoring of lesions, to count the number of airways, to quantify the amount of stored mucosubstances (Vs) within the epithelium, and to count the number of epithelial cells in terminal airways. No significant differences were found between lung regions or between groups of horses. Lack of regional differences in airway structures means that a biopsy sample can be used for diagnosis and investigation of diffusely distributed diseases. Airway inflammation was correlated with mucous cell metaplasia and Vs. Therefore, in horses, mucus accumulation is partly caused by increased number of mucous cells and is associated with airway inflammation. Therapy targeted to reduce airway inflammation will help reduce the excessive mucous accumulation in horses. 相似文献
7.
Waldner CL Kennedy RI Rosengren LB Pollock CM Clark ET 《The Canadian veterinary journal. La revue veterinaire canadienne》2010,51(11):1227-1238
Production losses from abortions, stillbirths, and early calf mortality were described for the 2002 calf crop in 203 beef herds in western Canada. A total of 1689 calves were examined. A summary diagnosis was reported for 64% of aborted calves, 78% of stillborn calves, 88% of neonatal calves, and 94% of the calves > 3 d of age. Diagnoses for aborted calves included: thyroid gland lesions, pneumonia, developmental anomalies, placentitis, and myocardial necrosis or myopathy. For stillborn calves, diagnostic findings included: dystocia, thyroid gland lesions, myocardial necrosis or myopathy, developmental anomalies, and skeletal myopathy or necrosis. The most common diagnoses for neonatal calves (≤ 3 d) were: pneumonia, skeletal myopathy or necrosis, myocardial necrosis or myopathy, accident or trauma, and septicemia. For older calves (3 d to 3 mo), the most common diagnoses included: starvation, abomasal ulcer or perforation, enteritis or colitis, pneumonia, and intestinal volvulus, obstruction, or perforation. 相似文献
8.
9.
Roth JA Hibbard B Frank DE Kesl L Robb EJ 《Veterinary therapeutics : research in applied veterinary medicine》2002,3(3):347-353
Holstein steer calves received a single injection of Miglyol (Sasol Chemical Industries, Ltd.) subcutaneously as a placebo, dihydroheptaprenol (DHP) (4 mg/kg) emulsified with lecithin subcutaneously, DHP in solution in Miglyol (4 mg/kg) subcutaneously, or DHP in solution in Miglyol (4 mg/kg) intranasally. The DHP emulsified in lecithin emulsion administered subcutaneously caused a substantial increase in body temperature, total leukocyte count, total neutrophil count, neutrophil cytochrome-c reduction, and neutrophil iodination 24 hours after administration and, for some of the parameters, at 48 hours. The DHP formulation in Miglyol did not have any of these effects when administered subcutaneously or intranasally. The carrier and formulation of DHP apparently have major effects on the biologic activity of DHP. 相似文献
10.