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   78480篇
  免费   4504篇
  国内免费   32篇
林业   4460篇
农学   2548篇
基础科学   474篇
  9770篇
综合类   12458篇
农作物   2934篇
水产渔业   3690篇
畜牧兽医   40388篇
园艺   958篇
植物保护   5336篇
  2018年   1124篇
  2017年   1227篇
  2016年   1146篇
  2015年   970篇
  2014年   1197篇
  2013年   3061篇
  2012年   2222篇
  2011年   2593篇
  2010年   1684篇
  2009年   1693篇
  2008年   2570篇
  2007年   2490篇
  2006年   2312篇
  2005年   2199篇
  2004年   2068篇
  2003年   2231篇
  2002年   1992篇
  2001年   2386篇
  2000年   2324篇
  1999年   1837篇
  1998年   743篇
  1997年   801篇
  1996年   721篇
  1995年   932篇
  1994年   766篇
  1993年   752篇
  1992年   1514篇
  1991年   1651篇
  1990年   1622篇
  1989年   1619篇
  1988年   1514篇
  1987年   1470篇
  1986年   1557篇
  1985年   1474篇
  1984年   1290篇
  1983年   1078篇
  1982年   761篇
  1979年   1185篇
  1978年   901篇
  1977年   857篇
  1976年   812篇
  1975年   842篇
  1974年   1041篇
  1973年   1081篇
  1972年   1028篇
  1971年   962篇
  1970年   935篇
  1969年   908篇
  1968年   765篇
  1967年   854篇
排序方式: 共有10000条查询结果,搜索用时 171 毫秒
31.
32.
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   
33.
Characterization of monoclonal antibodies directed against swine leukocytes   总被引:3,自引:0,他引:3  
Hybridomas were produced from fusions of the SP2/0 mouse myeloma with splenic cells from: 1) an outbred Sprague Dawley rat immunized with swine peripheral blood mononuclear (PBM) cells; 2) a (CBA/NDub X BALB/c Dub) F1 mouse immunized with concanavalin A (Con A) activated swine PBM cells and 3) a (BALB/c Dub X C3H/He Dub) F1 mouse immunized with swine thymocytes. The resulting supernatants were screened by a microcytotoxicity assay for activity against swine PBM cells. Four hybridomas (MSA1, MSA2, MSA3 and MSA4) were selected, cloned and characterized by their cell reactivity and effect on mitogenic assays. MSA1 and MSA2 belong to the rat IgG2b subclass. MSA3 and MSA4 are of the mouse IgG2a subclass. These monoclonal antibodies reacted in the following manner: MSA1 with monocytes, granulocytes, red blood cells and bone marrow cells; MSA2 with subset of T cells; MSA3 with B cells and subsets of T cells and monocytes (class II molecule) and MSA4, a pan-T cell reagent (E-rosette receptor). The involvement of the various cell types reactive to the different monoclonal antibodies in the mitogenic response of swine PBM cells to Con A, phytohemagglutinin (PHA) or pokeweed mitogen (PWM) was investigated by cellular depletion with monoclonal antibody plus complement. Cellular depletion of PBM cells with the following monoclonal antibodies plus complement treatment resulted in: MSA1, almost total reduction in the mitogenic response to low doses of Con A or PWM; MSA2, partial reduction in the proliferative responses to any concentration of Con A, PHA or PWM; MSA3, partial reduction in proliferative responses to low concentrations of Con A or PWM and 4) MSA4, total elimination of any proliferative response to Con A, PHA or PWM.  相似文献   
34.
35.
Ohne Zusammenfassung  相似文献   
36.
37.
38.
39.
40.
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