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   11200篇
  免费   819篇
  国内免费   7篇
林业   1059篇
农学   452篇
基础科学   87篇
  3009篇
综合类   360篇
农作物   576篇
水产渔业   1248篇
畜牧兽医   4084篇
园艺   202篇
植物保护   949篇
  2023年   99篇
  2022年   143篇
  2021年   291篇
  2020年   288篇
  2019年   258篇
  2018年   534篇
  2017年   525篇
  2016年   542篇
  2015年   416篇
  2014年   476篇
  2013年   727篇
  2012年   853篇
  2011年   827篇
  2010年   484篇
  2009年   404篇
  2008年   677篇
  2007年   646篇
  2006年   532篇
  2005年   495篇
  2004年   442篇
  2003年   391篇
  2002年   343篇
  2001年   215篇
  2000年   221篇
  1999年   187篇
  1998年   43篇
  1997年   49篇
  1996年   37篇
  1995年   23篇
  1994年   22篇
  1993年   29篇
  1992年   61篇
  1991年   44篇
  1990年   46篇
  1989年   49篇
  1988年   37篇
  1987年   43篇
  1986年   48篇
  1985年   48篇
  1984年   38篇
  1983年   35篇
  1982年   22篇
  1981年   17篇
  1979年   31篇
  1978年   30篇
  1977年   28篇
  1974年   26篇
  1973年   46篇
  1972年   33篇
  1971年   27篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
An imaging report is a vital communication tool between a radiologist and clinician. In a field where in‐person communication may not be readily available, it is imperative that the report clearly relays pertinent clinical information in a timely manner. The purpose of this observational study was to describe and compare opinions and expectations of small animal general practitioners, veterinary specialists, and veterinary radiologists regarding the imaging report. Online surveys were distributed, and data were collected from 202 veterinary clinicians and 123 veterinary radiologists. The majority (89%) of clinicians were satisfied with their imaging reports and stated that they read the radiology report as soon as it was available (92%). Just less than half (48%) of clinicians indicated it was standard of care that a board‐certified veterinary radiologist read all imaging studies. Radiologists and clinicians agreed that a clinical history (98% and 94%, respectively) and clinical question (82% and 68%, respectively) were needed to generate a good radiology report. Fifty‐five percent to 70% of clinicians prefer red bulleted reports, which included incidental findings (96%); while radiologists slightly favored prose reporting (37–46%). Clinicians found it helpful when additional imaging (86%), medical (71%), and surgical recommendations (73%) were made. About one‐third of specialists who had been in practice for >11 years thought they were better able to interpret imaging for their own specialty than the radiologist. Clinicians voiced discontentment with reports that were not completed in a timely manner or did not give a prioritized differential list. Further studies are warranted to provide a more in‐depth evaluation of veterinary radiology reporting structure and style.  相似文献   
62.
63.
64.
65.
66.
67.
68.
69.
  1. The aim of this work was to improve natural anti-predator behaviour of farm-reared gamebirds.

  2. We evaluated the anti-predator behaviour of reared red-legged partridge Alectoris rufa chicks kept in brooder houses in large groups (>350 chicks), trained and not trained by parent red-legged partridges acting as experienced tutors.

  3. The experiment consisted of two conditioned tests (a raptor model and a human) and two control tests, which were conducted during three consecutive phases of life (1–4, 15–17 and 30–32 d after hatching). The motor anti-predator behaviour, its duration, the intensity of response in chicks and alarm calls elicited by adults were recorded.

  4. Tutors elicited aerial alarm calls (76% of tests) and showed prolonged crouching (59% of tests) in response to the raptor model whereas uttering the ground alarm call (73% of tests) and showing vigilance behaviour (78% of tests) was the main pattern during the human test.

  5. Trained and not trained chicks showed similar motor behaviour in response to the raptor model (crouching) and the human test (escaping), but frequency of strong responses (all chicks responding) from chicks trained with tutors was double that of chicks trained without them, and chicks trained with tutors showed a higher frequency of long responses (41–60 s).

  6. This study indicates that anti-predator training programmes before release may improve behaviour of farm-reared partridges which may confer benefits to survival of birds.

  相似文献   
70.
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