全文获取类型
收费全文 | 923篇 |
免费 | 92篇 |
专业分类
林业 | 47篇 |
农学 | 15篇 |
93篇 | |
综合类 | 115篇 |
农作物 | 33篇 |
水产渔业 | 36篇 |
畜牧兽医 | 611篇 |
园艺 | 20篇 |
植物保护 | 45篇 |
出版年
2023年 | 22篇 |
2022年 | 10篇 |
2021年 | 21篇 |
2020年 | 31篇 |
2019年 | 27篇 |
2018年 | 28篇 |
2017年 | 18篇 |
2016年 | 26篇 |
2015年 | 29篇 |
2014年 | 39篇 |
2013年 | 39篇 |
2012年 | 51篇 |
2011年 | 56篇 |
2010年 | 29篇 |
2009年 | 39篇 |
2008年 | 35篇 |
2007年 | 40篇 |
2006年 | 32篇 |
2005年 | 25篇 |
2004年 | 27篇 |
2003年 | 24篇 |
2002年 | 36篇 |
2001年 | 17篇 |
2000年 | 16篇 |
1999年 | 13篇 |
1998年 | 11篇 |
1996年 | 10篇 |
1994年 | 11篇 |
1992年 | 11篇 |
1991年 | 13篇 |
1990年 | 11篇 |
1989年 | 8篇 |
1988年 | 6篇 |
1987年 | 10篇 |
1985年 | 13篇 |
1984年 | 10篇 |
1979年 | 6篇 |
1978年 | 5篇 |
1977年 | 8篇 |
1976年 | 8篇 |
1975年 | 7篇 |
1974年 | 7篇 |
1973年 | 12篇 |
1972年 | 11篇 |
1971年 | 7篇 |
1969年 | 5篇 |
1968年 | 5篇 |
1958年 | 5篇 |
1893年 | 5篇 |
1892年 | 5篇 |
排序方式: 共有1015条查询结果,搜索用时 78 毫秒
231.
JOHN V. YOVICH BSc BVMS A. S. TURNER BVSc MS DiplomateACVS F. W. SMITH BSME MSME PhD 《Veterinary surgery : VS》1985,14(3):221-229
The holding power of orthopedic screws in the third metacarpal and metatarsal cadaver bones of foals that were aged from 1 to 14 days was tested. Comparative trials between screws inserted at the same site in contralateral bones from the same foal were performed to compare the holding power of 5.5 mm cortical and 6.5 mm cancellous screws in the metaphysis, and the holding power of 5.5 and 4.5 mm cortical screws in the diaphysis. A MTS servohydraulic tensile testing machine was used to perform screw pullouts at a displacement rate of 19 mm/sec. There was no significant difference between maximum holding power of 5.5 mm cortical screws and 6.5 mm cancellous screws in the metaphysis when expressed as kg per mm of bone width at the screw insertion site (p = 0.097) or as kg per mm of screw thread engaged in the bone (p = 0.17). There was no significant difference in holding power of 5.5 and 6.5 mm screws in the proximal versus distal metaphysis (p = 0.10). The 5.5 mm screws had significantly greater holding power than the 4.5 mm screws in the diaphysis (p = 0.0097). Fixation failure at screw pullout was always due to bone shear. In internal fixation in foal bone, the 5.5 mm screws may be a suitable alternative to 6.5 mm screws in the metaphysis. Use of 5.5 mm rather than 4.5 mm screws is recommended in the diaphysis because of greater holding power. 相似文献
232.
Florida has the largest population of feral swine in the U.S.A. Feral swine have recreational and economic importance to hunters, trappers, taxidermists, and also to dealers who sell feral swine to hunting clubs. Hunters spent over 522 00 man-days hunting feral swine during the 1980–1981 hunting year. They killed nearly 103 000 hogs which they valued at over $58 each, for a total value of nearly $6 million. Trappers caught 25 000 head valued at about $ 700 000, and landowners collected about $1.2 million in hunting lease fees. Taxidermists received about $389 000 in gross income from mounting feral swine. Sales of feral swine to hunting clubs amounted to about $81 000.
Sales of feral swine through commercial livestock auctions were limited to 1620 head valued at only $16 800 in 1980. Thus, feral swine are important to Florida from a recreational standpoint, but not from the perspective of commercial agriculture.
If African swine fever were to enter Florida, there are many socio-economic factors associated with feral swine that must be carefully evaluated for eradication to be successful. 相似文献
233.
Studies of the immunomodulatory effects of low-level infection with Ostertagia ostertagi in calves 总被引:1,自引:0,他引:1
Possible immunomodulation by low-level infection with Ostertagia ostertagi was studied in 4-month-old calves. Six groups of 4 calves each were subjected to the following regimens: group 1--nonparasitized controls; group 2--nonparasitized, but challenge exposed at day 64 with Brucella abortus strain 19 vaccine (BA) and at day 78 with IV administration of a soluble third-stage larval (L3) antigen preparation of O ostertagi (OAG); group 3--nonparasitized, but challenge exposed at day 78 with 75 x 10(3) L3 of O ostertagi; group 4--continuously parasitized by weekly dosing with 30 x 10(3) L3 of O ostertagi; group 5--continuously parasitized by weekly dosing with 30 x 10(3) L3 of O ostertagi, then challenge exposed on day 64 with BA and on day 78 with IV inoculation of OAG; and group 6--continuously parasitized by weekly dosing with 30 x 10(3) L3 of O ostertagi, then challenge exposed on day 78 with 75 x 10(3) L3 of O ostertagi. Over the initial 10 weeks of the study, nonparasitized calves, (groups 1, 2, and 3) had higher body weight, blood lymphocyte (BL) response to phytohemagglutinin (PHA), and significantly (P less than 0.05) higher feed consumption and lymphocyte numbers, whereas parasitized calves (groups 4, 5, and 6) had higher BL responses to pokeweed mitogen (PWM) and significantly (P less than 0.05) higher neutrophil and eosinophil numbers, plasma pepsinogen (PP) values, and BL response to OAG.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
234.
235.
236.
The effect of storage on ammonia,cytokine, and chemokine concentrations in feline whole blood
下载免费PDF全文
![点击此处可从《Journal of Veterinary Emergency and Critical Care》网站下载免费的PDF全文](/ch/ext_images/free.gif)
237.
238.
Enterocolitis caused by Yersinia pseudotuberculosis was identified by bacterial culture and histopathology in a 5-month old suckler calf. No other significant enteric pathogens were detected. Diagnosis of this condition can be missed if selective media are not used for bacteriology and if histopathology is not attempted or the alimentary tract is unsuitable for examination. This is the first case report of Y. pseudotuberculosis infection in a calf in the United Kingdom. 相似文献
239.
Effect of induced chronic atrial fibrillation on exercise performance in Standardbred trotters
下载免费PDF全文
![点击此处可从《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Rikke Buhl Helena Carstensen Eva Zander Hesselkilde Bjørg Zinkernagel Klein Karen Margrethe Hougaard Kirsten Bomberg Ravn Ameli Victoria Loft‐Andersen Merle Friederike Fenner Christian Pipper Thomas Jespersen 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2018,32(4):1410-1419
240.
Spontaneous hemoperitoneum and anaphylactic shock associated with Hymenoptera envenomation in a dog
下载免费PDF全文
![点击此处可从《Journal of Veterinary Emergency and Critical Care》网站下载免费的PDF全文](/ch/ext_images/free.gif)