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   145056篇
  免费   7702篇
  国内免费   102篇
林业   6116篇
农学   4223篇
基础科学   884篇
  15852篇
综合类   27934篇
农作物   5567篇
水产渔业   6621篇
畜牧兽医   75201篇
园艺   1655篇
植物保护   8807篇
  2018年   1723篇
  2017年   1888篇
  2016年   1762篇
  2015年   1576篇
  2014年   1912篇
  2013年   5161篇
  2012年   3395篇
  2011年   4314篇
  2010年   2758篇
  2009年   2774篇
  2008年   4189篇
  2007年   4056篇
  2006年   3912篇
  2005年   3577篇
  2004年   3454篇
  2003年   3498篇
  2002年   3321篇
  2001年   4398篇
  2000年   4513篇
  1999年   3570篇
  1998年   1365篇
  1997年   1396篇
  1995年   1652篇
  1994年   1413篇
  1993年   1383篇
  1992年   3064篇
  1991年   3236篇
  1990年   3201篇
  1989年   3214篇
  1988年   3001篇
  1987年   3042篇
  1986年   3105篇
  1985年   3021篇
  1984年   2453篇
  1983年   2183篇
  1982年   1484篇
  1979年   2359篇
  1978年   1884篇
  1977年   1655篇
  1976年   1585篇
  1975年   1727篇
  1974年   2229篇
  1973年   2293篇
  1972年   2245篇
  1971年   2092篇
  1970年   1998篇
  1969年   1790篇
  1968年   1546篇
  1967年   1609篇
  1966年   1441篇
排序方式: 共有10000条查询结果,搜索用时 93 毫秒
71.
72.
73.
Star catalogues     
  相似文献   
74.
75.
76.
77.
78.
The feet of three two-humped camels (Camelus bactrianus), one lama (Lama glama) and four alpacas (Lama pacos) from zoos and a circus in the Netherlands were examined for the mange-mite Choroptes bovis. Mites were found on two of the camels, the lama, and three of the alpacas. On one camel and one alpaca small mange lesions on the feet were present. This is the first report of Chorioptes bovis and chorioptic mange in the two-humped camel.  相似文献   
79.
Various combinations of reoviruses and coccidia were studied to see if interactions would occur. Two reoviruses were used: virus 2035, a moderate to low pathogen, and virus 2177, a nonpathogen. Coccidia used were Eimeria acervulina, E. mitis, and E. maxima at dosages of 10(3) or 10(4) sporulated oocysts/chick and E. brunetti at 10(4) sporulated oocysts/chick. In Hubbard-Hubbard cockerels, a combination of virus 2035 and E. acervulina (10(4) oocysts/chick) or E. maxima (10(3) oocysts/chick) significantly (P less than or equal to 0.05) increased the frequency of stunting (% of chicks with body weight less than 80% of controls) and further depressed weight gain over that seen with either virus or coccidia alone. Conversely, virus 2177 ameliorated the same effects in Shaver-Arbor Acre cockerels given 10(4) oocysts/chick of E. mitis or E. maxima. The interaction could not be attributed to changes in the degree of coccidial infection based on oocyst production. Reovirus did not generally change the effect of coccidia on levels of plasma pigment and plasma protein. In Hubbard-Hubbard cockerels, coccidia-induced effects were not ameliorated by virus 2177, suggesting that breed difference in interaction can be expected.  相似文献   
80.
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   
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