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   17612篇
  免费   1566篇
  国内免费   38篇
耳鼻咽喉   197篇
儿科学   579篇
妇产科学   430篇
基础医学   2579篇
口腔科学   450篇
临床医学   2017篇
内科学   3118篇
皮肤病学   349篇
神经病学   1495篇
特种医学   573篇
外科学   2088篇
综合类   293篇
一般理论   14篇
预防医学   1840篇
眼科学   351篇
药学   1114篇
中国医学   47篇
肿瘤学   1682篇
  2022年   149篇
  2021年   337篇
  2020年   246篇
  2019年   315篇
  2018年   334篇
  2017年   267篇
  2016年   324篇
  2015年   342篇
  2014年   488篇
  2013年   748篇
  2012年   1034篇
  2011年   1034篇
  2010年   606篇
  2009年   577篇
  2008年   909篇
  2007年   974篇
  2006年   901篇
  2005年   853篇
  2004年   878篇
  2003年   832篇
  2002年   753篇
  2001年   355篇
  2000年   357篇
  1999年   347篇
  1998年   210篇
  1997年   194篇
  1996年   145篇
  1995年   154篇
  1994年   138篇
  1993年   150篇
  1992年   309篇
  1991年   278篇
  1990年   242篇
  1989年   248篇
  1988年   182篇
  1987年   211篇
  1986年   199篇
  1985年   233篇
  1984年   158篇
  1983年   147篇
  1982年   122篇
  1981年   108篇
  1979年   142篇
  1978年   104篇
  1977年   100篇
  1976年   103篇
  1974年   97篇
  1973年   111篇
  1972年   111篇
  1971年   103篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
63.
64.
Simultaneous recording of adult subjects sipping small amounts of fluid from a cup have been obtained by videofluoroscopy together with feeding respiratory patterns and swallow sounds from the Exeter Dysphagia Assessment Technique (EDAT). These allowed visual representations of respiration and swallow sounds to be superimposed on a videofluoroscopy recording using a split-screen technique. Sequentially numbered, 1/50 sec, half-frame photographic prints were examined and schematic drawings of the relevant radiographs were made. These were superimposed on to the actual EDAT printed chart of the same swallow event, theri exact time relationship with respiration and cervical swallow sounds being preserved. The results allow events in the barium videofluoroscopy to be related to events in the feeding respiratory pattern and swallow sounds recorded by EDAT.  相似文献   
65.
One of the most common errors in model surgery for orthognathic surgery is in the mounting of the models on the articulator. This study assessed the ability of one type of face-bow to transfer the maxillary model to the articulator. Twenty-five consecutive mountings were evaluated by calculating the angle made between the maxillary occlusal plane on the cephalogram and comparing it with the maxillary occlusal plane angle on the articulator. An accurate face-bow transfer should transfer this angle, making the two similar. It was found that a significant difference between the maxillary occlusal plane angle on the cephalogram and the articulator was found in the average case. The implications of such errors and a technique to avoid them are presented.  相似文献   
66.
It was proposed that differences between paranoid and nonparanoid schizophrenics in the processing of affective information may reflect underlying differences in their schema for emotion-laden information. Performances of 14 paranoid schizophrenics, 13 nonparanoid schizophrenics, and 15 matched controls were compared on a facial affect judgment task, and a matched control task comprising geometric figures largely devoid of emotional information. Subjects were required to rate friendliness, select an emotion label, and subsequently to remember the stimuli. Nonparanoids were deficient in overall labeling of facial affect, suggesting a weak cognitive schema for emotional information. The paranoids were particularly more accurate than the nonparanoids at labeling the negative facial affects, suggesting well-developed negative emotional aspects in their cognitive schema. Unexpectedly, nonparanoids relative to paranoids displayed a greater memory deficit in the recognition of geometric figures than in the recognition of faces. The nonparanoid deficit suggests these subjects may have poorly organized schema for remembering less structured nonverbal information. The findings support the idea of fundamental cognitive processing differences between paranoid and nonparanoid schizophrenia.  相似文献   
67.
68.
Hospitalized neonates are commonly colonized soon after birth with Staphylococcus aureus. The majority of neonates do not develop infectious sequelae; however, premature neonates appear to be more susceptible to serious infections, such as pneumonia. We report a case of an extremely low birth weight infant who developed necrotizing pneumonia due to methicillin-resistant Staphylococcal aureus (MRSA). The MRSA isolate from this neonate is identical to the strains that have been causing primarily community-associated skin and soft tissue infections. The severe course of this patient may be attributed to the presence of the Panton-Valentine leukocidin gene, a well-known virulence factor leading to soft tissue and pulmonary infections.  相似文献   
69.
Summary Several components of a system for structure generation are now well developed. HIPPO is a program that characterises a receptor binding site for potential target sites within the cavity that can be used in de novo design. The target sites include simple and complex hydrogen bonds, covalent bonds and bonds to metal ions. The SPROUT program for structure generation consists of two main components: the first is skeleton generation, followed by atom substitution to convert the solution skeletons to molecules. A new method of skeleton generation is presented here, where part skeletons are grown outwards from each target site. The part skeletons are then connected together to form solution skeletons. Finally the CAESA program is described, that ranks the output from SPROUT according to ease of synthesis.  相似文献   
70.
One hundred methanolic plant extracts, 96 of which had documented medicinal uses by British Columbian native peoples, were screened for antibiotic activity against 11 bacterial strains. Eighty-five percent were found to have significant antibiotic activity against at least two of the bacteria tested. Ninety-five percent of the plants categorized as potential antibiotics based on their ethnobotanical usage were found to exhibit significant antibiotic activity. Seventy-five were found to be active against methicillin-resistant Staphylococcus aureus, 46 were active against an antibiotic supersusceptible strain of Pseudomonas aeruginosa and 18 of these were also active against a wild type strain. The extracts with the broadest spectra of activity were prepared from: Alnus rubra bark and catkins, Fragaria chiloensis leaves, Moneses uniflora aerial parts, and Rhus glabra branches.  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