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   174篇
  免费   0篇
林业   1篇
农学   22篇
  2篇
综合类   4篇
农作物   1篇
水产渔业   40篇
畜牧兽医   100篇
植物保护   4篇
  2013年   1篇
  2012年   2篇
  2011年   7篇
  2010年   8篇
  2009年   9篇
  2008年   8篇
  2007年   3篇
  2006年   8篇
  2005年   6篇
  2004年   1篇
  2003年   1篇
  1999年   1篇
  1998年   7篇
  1997年   9篇
  1996年   3篇
  1995年   6篇
  1994年   5篇
  1993年   5篇
  1992年   1篇
  1991年   6篇
  1990年   5篇
  1989年   7篇
  1988年   3篇
  1987年   7篇
  1986年   8篇
  1985年   6篇
  1984年   5篇
  1983年   1篇
  1982年   1篇
  1981年   5篇
  1980年   2篇
  1979年   4篇
  1978年   3篇
  1973年   1篇
  1971年   1篇
  1963年   2篇
  1958年   2篇
  1957年   3篇
  1956年   4篇
  1955年   1篇
  1954年   2篇
  1953年   2篇
  1947年   2篇
排序方式: 共有174条查询结果,搜索用时 359 毫秒
151.
Current reports advise against attempting simultaneous bilateral mastectomy in the dog. However, total mastectomy may be the most logical treatment for all dogs with mammary tumors in view of newer evidence suggesting a multicentric origin for this disease. A surgical technique for simultaneous bilateral mastectomy was evaluated in 22 dogs with mammary tumors. The procedure was successfully performed in selected patients and healing occurred without serious complications. The technique, rationale, and recommendations for use of this procedure are presented.  相似文献   
152.
Abstract. Nodular gill disease characterized by severe multifocal epithelial hyperplasia was diagnosed in a group of rainbow trout, Salmo gairdneri Richardson, fingerlings. Gills of a large proportion of fish transferred from the affected tank to smaller aquaria showed a marked decrease in severity of the lesions after 2 months. Repair of hyperplastic lesions may occur in various forms of proliferative gill disease, provided that the basement membrane lining the primary and secondary disease, provided that the basement membrane lining the filaments and lamellae remains intact.  相似文献   
153.
Fourteen interfragmentary orthopedic wire configurations were tested in torsion using a transverse fracture polyvinylchloride pipe model. These models included single and double Kirschner pins with and without orthopedic wire added to the configuration. The orthopedic wire was applied in either an encircling, figure-of-eight (skewer pin), or cruciate pattern. Double Kirschner pins were applied in a mono- or biplanar fashion. An external fixator model was also tested. Stiffness, yield load, safe load, and energy of absorption were measured and calculated for each model. Orthopedic wire added to any configuration increased stiffness. All single pin configurations with orthopedic wire and the external fixator had the highest stiffness. Two Kirschner pins had a higher torsional yield load and safe load than single pin configurations with or without orthopedic wire. The external fixator model had the highest torsional yield load, safe load and energy of absorption of all configurations tested. However, the external fixator was only significantly different in safe load from the 90° biplanar configurations with wire and the cross pin configuration with encircling wire. The 90° biplanar configurations with wire and the cross pin configuration with encircling wire were equally as effective as the external fixator model in yield load and energy of absorption.  相似文献   
154.
A discussion of postsurgical convalescence as presented before the New York Academy of Sciences is reviewed with an update and a detailed discussion of some factors that influence immediate postsurgical recovery.  相似文献   
155.
Abstract. This report describes the gross and histopathological appearance as well as the bacteriological findings in an outbreak of panophthalmitis in farmed chinook salmon. In all cases, the bacteria were either Mycobacterium neoaurum or an unidentified Rhodococcus spp.; in some fish, both types were present in roughly equal numbers, while in others, one type dominated. Despite occasionally recovering the bacteria from kidney or spleen, no lesions were found in these or in any other organ, suggesting that the localization to the eye was not incidental, but a specific tropism. Nevertheless, the possibility of predisposing cause(s) must be considered and these are discussed.  相似文献   
156.
ABSTRACT The determinants of rural and urban community population change over the period 1991–2001 are investigated at a very fine level of disaggregation for Canada. The study examines the influence of local amenities, economic factors, and agglomeration economies on population growth for age cohorts starting from the very young to the elderly. Motivated by the objective of assessing the overall jobs versus people question in economic development, the emphasis is on estimating the relative contribution of groupings of variables in explaining the variations in population change rather than the contribution of individual variables. Results indicate that rural and urban populations are influenced to differing degrees by amenity, economic, and urban scale groupings of variables and that there are variations among age cohorts in both urban and rural areas. While economic variables are the most influential in population change for all rural cohorts, their contribution somewhat diminishes with age. In urban areas, amenity, and economic variable groupings have approximately equal importance across all cohorts. For the key young adult cohort, the economic grouping is clearly the most influential in rural areas, while it is a close second to amenities in urban areas.  相似文献   
157.
Abstract. An 'oedema syndrome' caused mortality of 55·5% in brood brown trout approximately 2 months after spawning. The pathology and clinical biochemistry of the condition are described. It is suggested that the severe hypoproteinaemia and anaemia were due mainly to the traditional reduction in feed levels prior to spawning at a time when the water temperatures were abnormally high. It is also suggested, however, that the syndrome would not have occurred if the fish had not developed an aeromonad infection prior to stripping. Concurrent fungal infection and subsequent extremely low water temperatures are also thought to have played a role.  相似文献   
158.
159.
MARK 《国际木业》2004,34(9):3-3
近日在北京康洁公司总部举办“中国居室门发展趋势高层论坛”。来自木业行业的机构领导、国内外专家、生产厂家的负责人以及人民日报、北京晚报、北京青年报、消费日报、精品购物、人物周刊和国际木业等媒体的记者出席会议。  相似文献   
160.
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