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   70457篇
  免费   3814篇
  国内免费   43篇
林业   2484篇
农学   2292篇
基础科学   393篇
  8927篇
综合类   11250篇
农作物   2357篇
水产渔业   3864篇
畜牧兽医   37669篇
园艺   817篇
植物保护   4261篇
  2019年   630篇
  2018年   1094篇
  2017年   1237篇
  2016年   1124篇
  2015年   885篇
  2014年   1140篇
  2013年   2567篇
  2012年   2034篇
  2011年   2484篇
  2010年   1725篇
  2009年   1672篇
  2008年   2488篇
  2007年   2367篇
  2006年   2185篇
  2005年   2024篇
  2004年   1944篇
  2003年   1978篇
  2002年   1702篇
  2001年   2561篇
  2000年   2640篇
  1999年   2047篇
  1998年   793篇
  1997年   750篇
  1996年   655篇
  1995年   829篇
  1994年   718篇
  1993年   670篇
  1992年   1515篇
  1991年   1668篇
  1990年   1535篇
  1989年   1447篇
  1988年   1389篇
  1987年   1436篇
  1986年   1350篇
  1985年   1311篇
  1984年   1113篇
  1983年   938篇
  1982年   645篇
  1979年   980篇
  1978年   766篇
  1977年   697篇
  1976年   671篇
  1975年   736篇
  1974年   808篇
  1973年   782篇
  1972年   792篇
  1971年   677篇
  1970年   628篇
  1969年   723篇
  1967年   675篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
21.
22.
Star catalogues     
  相似文献   
23.
24.
25.
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   
26.
Thirteen mixed-breed beef bulls, 1 to 4 years old, were used to determine the effect of live and dead filarial nematodes, Setaria labiatopapillosa, placed in the vaginal cavity of the testes. When dead worms were used, granulomatous lesions developed on the tunica vaginalis parietalis in 7 of 8 testes. The lesions were similar to those seen in some clinical cases of periorchitis. Similar lesions developed in 5 of 6 testes after live worms were implanted in the vaginal cavity of the testes and tetramisole (8 mg/kg) was injected subcutaneously 6 days after implantation. When live worms were implanted and tetramisole was not given, lesions developed in 3 of 6 testes. It was concluded that the granulomatous reaction was a local response to dead or killed S labiatopapillosa.  相似文献   
27.
28.
In addition to the well-defined phenolic estrogens in human pregnancy urine there appears to be another estrogenic substance which is a neutral non-ketonic compound.  相似文献   
29.
30.
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