首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   200028篇
  免费   10932篇
  国内免费   1961篇
林业   9883篇
农学   8064篇
基础科学   2355篇
  24689篇
综合类   37756篇
农作物   8315篇
水产渔业   9591篇
畜牧兽医   96362篇
园艺   3255篇
植物保护   12651篇
  2021年   1861篇
  2020年   2083篇
  2019年   2395篇
  2018年   3040篇
  2017年   3645篇
  2016年   3279篇
  2015年   3166篇
  2014年   3666篇
  2013年   8067篇
  2012年   6575篇
  2011年   7597篇
  2010年   5497篇
  2009年   5379篇
  2008年   7333篇
  2007年   6975篇
  2006年   6615篇
  2005年   6041篇
  2004年   5367篇
  2003年   5408篇
  2002年   5024篇
  2001年   5919篇
  2000年   5854篇
  1999年   4864篇
  1998年   2160篇
  1997年   2089篇
  1996年   1991篇
  1995年   2225篇
  1994年   1957篇
  1993年   1971篇
  1992年   3758篇
  1991年   3937篇
  1990年   3964篇
  1989年   3996篇
  1988年   3664篇
  1987年   3575篇
  1986年   3578篇
  1985年   3395篇
  1984年   2803篇
  1983年   2481篇
  1979年   2494篇
  1978年   2000篇
  1977年   1776篇
  1976年   1715篇
  1975年   1842篇
  1974年   2258篇
  1973年   2249篇
  1972年   2276篇
  1971年   2084篇
  1970年   2086篇
  1969年   1861篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
The medical records of 38 horses with puncture wounds of the navicular bursa were reviewed. Only 12 horses had a satisfactory outcome (breeding or riding). Of the remaining 26 horses, 19 were euthanized, five were sold due to persistent severe lameness, one died, and one was lost to long-term follow-up. Different combinations of conservative management prior to surgical debridement and drainage of the navicular bursa were unsuccessful in resolving the condition. Horses that were treated surgically within 1 week of the injury and had a hind leg affected had the best chance of a satisfactory outcome. Additional wound debridement was necessary in 15 horses after initial surgical treatment. The most common complications encountered were navicular bone osteomyelitis and sepsis of the deep digital flexor tendon. Thirteen of 14 horses that had rupture of the deep digital flexor tendon and subluxation of the distal interphalangeal joint had an unsatisfactory outcome. One mare subsequently developed ankylosis of the distal interphalangeal joint and was a useful brood mare. Two horses that had biaxial palmar digital neurectomy because of persistent lameness were later euthanized because of navicular bone fracture and rupture of the deep digital flexor tendon. Results from limited numbers of bacterial cultures and antibiotic sensitivities suggest that penicillin and an aminoglycoside antibiotic should be used as initial antibiotic therapy. Immediate surgical debridement and appropriate antibiotic treatment are recommended as the minimum therapy for penetrating wounds of the navicular bursa in horses.  相似文献   
82.
Summary Acute febrile diseases are characterized by specific and non-specific symptoms. The non-specific responses are presented under the headings: fever, inflammation and pain, experimental models for investigating febrile reactions, haematologic changes, blood biochemical changes, cardiovascular effects, changes in gastric function, and the effects of fever upon pharmacokinetics of drugs. It was the purpose of this review to describe present concepts of thermoregulation and fever, the associated reactions produced by bacterial pyrogens and the mechanisms of these reactions. The available data illustrate, that many questions have not yet been clearly answered. However, the entire field of research involving endogenous substances, such as interleukin-1, is now moving ahead with great speed. Furthermore, there is some evidence which suggests that fever and the associated lower plasma zinc and iron levels act together as a co-ordinated non-specific host defence mechanism. Since experimental fever has a distinct effect upon the pharmacokinetics of drugs, more attention should be given to this aspect.  相似文献   
83.
84.
85.
86.
87.
W A 《Science (New York, N.Y.)》1886,7(170):416-417
  相似文献   
88.
89.
90.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号