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   39篇
  免费   2篇
  1篇
综合类   23篇
农作物   1篇
畜牧兽医   14篇
园艺   1篇
植物保护   1篇
  2016年   2篇
  2014年   1篇
  2013年   3篇
  2011年   1篇
  2010年   1篇
  1999年   1篇
  1998年   3篇
  1997年   1篇
  1994年   2篇
  1993年   1篇
  1992年   2篇
  1990年   1篇
  1989年   1篇
  1985年   1篇
  1973年   1篇
  1972年   2篇
  1971年   1篇
  1970年   1篇
  1969年   2篇
  1968年   2篇
  1966年   3篇
  1963年   1篇
  1957年   1篇
  1948年   1篇
  1945年   1篇
  1939年   1篇
  1938年   1篇
  1933年   2篇
排序方式: 共有41条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Disease of geese caused by a new herpesvirus   总被引:3,自引:0,他引:3  
A goose flock farmed outdoors in south-eastern Queensland suffered an outbreak of peracute disease with high death rate (97%). Small button ulcers and large plaques overlying lymphocyte aggregates were present on the mucosa of the small intestine of affected birds. Small white foci of necrosis and focal haemorrhages were seen in the livers. Numerous intranuclear inclusion bodies were observed microscopically in hepatocytes and a herpesvirus which grew rapidly in chicken kidney cells was isolated from tissues. Duck virus enteritis (DVE) was suspected but DVE antiserums failed to neutralise the virus. Further serological studies with a limited range of known avian herpesviruses have failed to identify the virus. Experimental transmission resulted in high mortality in geese (100%), lower mortality in ducklings and nil mortality in chickens. Surveillance studies showed no evidence of infection in domestic and wild birds beyond the original farm and the infection appears not to have been established in the area. Wild ducks, which were frequent visitors to the farm dam, were considered the most likely source of the infection.  相似文献   
5.
6.
7.
本项研究旨在探明甘蓝型油菜突变体Ap-Tengbe无花瓣性状的遗传规律,‘Ap-Tengbe’和德国栽培品种‘Falcon’之间通过正反交产生两个方向的F1,BC1-1(F1和‘Ap-Tengebe’之间),BC1-2(F1和‘Falcon’之间)以及F2各遗传群体,根据田间各遗传群体PDgr(花瓣度)的观察和统计,作者提出‘Ap-Tenge’突变体无花瓣性状的遗传由细胞质和两对核隐性基因共同控制  相似文献   
8.
9.
10.
In the hypothesis advanced here it is supposed that the field, in which rocks at the lunar surface acquired the remanent magnetization found through the Apollo project, arose from permanent magnetization of the deep interior of the moon. This theory involves the assumption that the moon, apart from a surface shell, accreted cold and remained below the Curie point of iron until sometime later than 3 x 10(9) years ago. The magnetization was acquired as the moon formed in a gas sphere in the strong magnetic field of the early sun.  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