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   9250篇
  免费   912篇
  国内免费   15篇
耳鼻咽喉   133篇
儿科学   275篇
妇产科学   163篇
基础医学   1150篇
口腔科学   386篇
临床医学   887篇
内科学   1942篇
皮肤病学   135篇
神经病学   1041篇
特种医学   207篇
外科学   1413篇
综合类   199篇
一般理论   10篇
预防医学   1035篇
眼科学   251篇
药学   481篇
中国医学   2篇
肿瘤学   467篇
  2021年   116篇
  2019年   92篇
  2018年   148篇
  2017年   94篇
  2016年   78篇
  2015年   115篇
  2014年   168篇
  2013年   382篇
  2012年   426篇
  2011年   443篇
  2010年   253篇
  2009年   247篇
  2008年   463篇
  2007年   531篇
  2006年   492篇
  2005年   495篇
  2004年   523篇
  2003年   488篇
  2002年   505篇
  2001年   82篇
  2000年   89篇
  1999年   72篇
  1998年   106篇
  1997年   110篇
  1996年   90篇
  1995年   77篇
  1994年   86篇
  1993年   96篇
  1992年   75篇
  1991年   75篇
  1989年   80篇
  1988年   81篇
  1986年   58篇
  1985年   82篇
  1984年   114篇
  1983年   111篇
  1982年   149篇
  1981年   139篇
  1980年   150篇
  1979年   91篇
  1978年   119篇
  1977年   104篇
  1976年   99篇
  1975年   78篇
  1974年   55篇
  1973年   78篇
  1972年   66篇
  1964年   66篇
  1962年   57篇
  1961年   55篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
Richard E. Clark in his widely published comprehensive studies and meta-analyses of the literature on computer assisted instruction (CAI) has decried the lack of carefully controlled research, challenging almost every study which shows the computer-based intervention to result in significant post-test proficiency gains over a non-computer-based intervention. We report on a randomized study in a medical school setting where the usual confounders found by Clark to plague most research, were carefully controlled. PlanAlyzer is a microcomputer-based, self-paced, case-based, event-driven system for medical education which was developed and used in carefully controlled trials in a second year medical school curriculum to test the hypothesis that students with access to the interactive programs could integrate their didactic knowledge more effectively and/or efficiently than with access only to traditional textual “nonintelligent” materials. PlanAlyzer presents cases, elicits and critiques a student's approach to the diagnosis of two common medical disorders: anemias and chest pain. PlanAlyzer uses text, hypertext, images and critiquing theory. Students were randomized, one half becoming the experimental group who received the interactive PlanAlyzer cases in anemia, the other half becoming the controls who received the exact same content material in a text format. Later in each year there was a crossover, the controls becoming the experimentals for a similar intervention with the cardiology PlanAlyzer cases. Preliminary results at the end of the first two full trials shows that the programs have achieved most of the proposed instructional objectives, plus some significant efficiency and economy gains. 96 faculty hours of classroom time were saved by using PlanAlyzer in their place, while maintaining high student achievement. In terms of student proficiency and efficiency, the 328 students in the trials over two years were able to accomplish the project's instructional objectives, and the experimentals accomplished this in 43% less time than the controls, achieving the same level of mastery. However, in spite of these significant efficiency findings, there have been no significant proficiency differences (as measured by current factual and higher order multiple choice post-tests) between the experimental and control groups. Very careful controls were used to avoid what Clark has found to be the most common confounders of CAI research. Accordingly, this research proved Clark's rival hypothesis, that the computer, in itself, does not appear to contribute to proficiency gains, at least as measured by our limited post-testing. Clark's position is that the computer is primarily a vehicle—as is either a pill or a hypodermic needle for delivering a drug. The hypodermic needle can deliver the drug more efficiently than can the pill, (as can the computer deliver the subject matter content more efficiently, as our research indicates), but the same content is delivered. At the same time, we proved our own hypothesis, as far as efficiency gains resulting from the computer are concerned. However, going beyond Clark's research, we may be teaching processes both more effectively and efficiently with the computer (experience in problem-solving or clinical reasoning and pattern recognition) which our current post-tests do not adequately measure. Our on-going research suggests additional inquiry in several areas: better evaluation instruments to measure the clinical reasoning skills PlanAlyzer was designed to teach; the addition of more advanced cases to determine if this might transform efficiency gains of the computer group into proficiency gains; the addition of enhanced graphic decision support tools and other pedagogical enhancements including cognitive feedback to strengthen PlanAlyzer's power to teach complex concepts of medical decision-making.  相似文献   
6.
7.
8.
A brief review of the developmental background of the lateral cervical sinuses, fistulas, cysts and auricles has been presented. In all likelihood they are of branchial cleft origin. Surgical excision is the recommended treatment as shown in the cases described.  相似文献   
9.
10.
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