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   354篇
  免费   73篇
林业   16篇
农学   6篇
基础科学   1篇
  35篇
综合类   29篇
农作物   7篇
水产渔业   32篇
畜牧兽医   282篇
园艺   10篇
植物保护   9篇
  2023年   2篇
  2022年   3篇
  2021年   10篇
  2020年   12篇
  2019年   13篇
  2018年   17篇
  2017年   10篇
  2016年   6篇
  2015年   7篇
  2014年   8篇
  2013年   15篇
  2012年   28篇
  2011年   29篇
  2010年   8篇
  2009年   15篇
  2008年   16篇
  2007年   19篇
  2006年   30篇
  2005年   10篇
  2004年   15篇
  2003年   17篇
  2002年   13篇
  2001年   4篇
  2000年   2篇
  1999年   6篇
  1998年   4篇
  1997年   3篇
  1996年   4篇
  1995年   9篇
  1994年   4篇
  1992年   4篇
  1991年   2篇
  1989年   6篇
  1985年   3篇
  1984年   5篇
  1983年   10篇
  1982年   12篇
  1981年   9篇
  1979年   2篇
  1978年   8篇
  1977年   2篇
  1976年   4篇
  1974年   1篇
  1973年   1篇
  1972年   2篇
  1971年   3篇
  1970年   1篇
  1969年   3篇
  1968年   1篇
  1942年   1篇
排序方式: 共有427条查询结果,搜索用时 15 毫秒
1.
2.
3.
The radial carpal and intermediate carpal bones were found to be fused in a four year old Quarterhorse stallion having a subtle forelimb lameness. Clinical examination, diagnostic local anesthesia, radiography and arthroscopy were used to arrive at the diagnosis. A cause could not be established, although perinatal deformation of cartilagenous carpal bone templates is suspected. A similar case of carpal bone fusion was found among carpi collected for an anatomical study, indicating this condition may be more common than expected. Clinicians should carefully evaluate the flexed lateral view of the carpus for proximal movement of the intermediate and ulnar carpal bones in young horses presented for carpal lameness. The significance of this condition will remain uncertain until its incidence and relationship to lameness are better defined.  相似文献   
4.
5.
6.
7.
8.
9.
Dental nerve blocks provide excellent pain management for many oral procedures. They are easy and inexpensive to perform, provide a rapid onset of action, and work in concert with anesthetic and other analgesic modalities. This article explains how to administer various dental nerve blocks and discusses the indications and precautions associated with their use.  相似文献   
10.
The integrated modelling of coupled socio-ecological systems in land-change science requires innovative model concepts capable of grasping the interrelations between socioeconomic and natural components. Here, we discuss the integrated socio-ecological model SERD (Simulation of Ecological Compatibility of Regional Development) that was developed for the municipality of Reichraming in Upper Austria in a participative 2-year process involving local stakeholders. SERD includes three main components: (1) an agent-based actors module that simulates decisions of farmsteads, the municipal administration and other important actors; (2) a spatially explicit (GIS based) land-use module that simulates land-use change at the level of individual parcels of land and (3) an integrated socio-ecological stock-flow module that simulates carbon and nitrogen flows through both socioeconomic and ecological system compartments. We report on outcomes of a scenario analysis that outlines possible future trajectories depending on both external (e.g. agricultural subsidies and prices) and internal (e.g. innovation, willingness to co-operate) factors. We find that both external and internal factors can affect the behaviour of the integrated system considerably. Local and regional policies are found to be able to counteract adverse global socioeconomic conditions to some extent, but not to reverse the trend altogether. We also find strong interdependencies between socioeconomic and ecological components of the system. Fully evaluating these interdependencies is, however, not possible at the local scale alone and will require explicit consideration of higher-level effects in future research.  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