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   2435758篇
  免费   188435篇
  国内免费   8397篇
耳鼻咽喉   33903篇
儿科学   76124篇
妇产科学   68802篇
基础医学   337323篇
口腔科学   70468篇
临床医学   214376篇
内科学   487318篇
皮肤病学   57073篇
神经病学   197836篇
特种医学   98728篇
外国民族医学   628篇
外科学   380797篇
综合类   57513篇
现状与发展   8篇
一般理论   813篇
预防医学   183110篇
眼科学   55054篇
药学   177339篇
  9篇
中国医学   4761篇
肿瘤学   130607篇
  2018年   22972篇
  2016年   21235篇
  2015年   23846篇
  2014年   33359篇
  2013年   50433篇
  2012年   63652篇
  2011年   67994篇
  2010年   41602篇
  2009年   40480篇
  2008年   64372篇
  2007年   69537篇
  2006年   70957篇
  2005年   68590篇
  2004年   66099篇
  2003年   64339篇
  2002年   62086篇
  2001年   115402篇
  2000年   119020篇
  1999年   100136篇
  1998年   28700篇
  1997年   25871篇
  1996年   26198篇
  1995年   25735篇
  1994年   23983篇
  1993年   22456篇
  1992年   80712篇
  1991年   78348篇
  1990年   76056篇
  1989年   73440篇
  1988年   68253篇
  1987年   67224篇
  1986年   63817篇
  1985年   61087篇
  1984年   46339篇
  1983年   39094篇
  1982年   23988篇
  1981年   21777篇
  1980年   20422篇
  1979年   43003篇
  1978年   31020篇
  1977年   26585篇
  1976年   24208篇
  1975年   26345篇
  1974年   31230篇
  1973年   30114篇
  1972年   28379篇
  1971年   26478篇
  1970年   24642篇
  1969年   23456篇
  1968年   21943篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Children who expect they can bring about good outcomes and avoid bad outcomes tend to experience more personal successes. Little is known about factors that contribute to these ‘control expectancies’. The purpose of the present study was to determine whether children's internal control expectancies occur in the context of parents’ internal control expectancies, low family strain, and high family cohesiveness and whether these factors are more strongly related to daughters’ than sons’ control expectancies. A community sample of 85 children aged 9–11 years and their parents (85 mothers; 63 fathers) completed rating scales. Fathers’ more internal control expectancies and mothers’ reports of fewer family strains were associated with daughters’ but not sons’ greater internal control expectancies, and greater family cohesiveness was related to both daughters’ and sons’ internal control orientations. These findings suggest that family factors may contribute to children's, particularly daughters’, development of internal control expectancies.  相似文献   
102.
Individuals with sudden unilateral deafness offer a unique opportunity to study plasticity of the binaural auditory system in adult humans. Stimulation of the intact ear results in increased activity in the auditory cortex. However, there are no reports of changes at sub-cortical levels in humans. Therefore, the aim of the present study was to investigate changes in sub-cortical activity immediately before and after the onset of surgically induced unilateral deafness in adult humans. Click-evoked auditory brainstem responses (ABRs) to stimulation of the healthy ear were recorded from ten adults during the course of translabyrinthine surgery for the removal of a unilateral acoustic neuroma. This surgical technique always results in abrupt deafferentation of the affected ear. The results revealed a rapid (within minutes) reduction in latency of wave V (mean pre = 6.55 ms; mean post = 6.15 ms; p < 0.001). A latency reduction was also observed for wave III (mean pre = 4.40 ms; mean post = 4.13 ms; p < 0.001). These reductions in response latency are consistent with functional changes including disinhibition or/and more rapid intra-cellular signalling affecting binaurally sensitive neurons in the central auditory system. The results are highly relevant for improved understanding of putative physiological mechanisms underlying perceptual disorders such as tinnitus and hyperacusis.  相似文献   
103.
104.
105.
106.
We present a patient with both dynamic left ventricular outflow tract obstruction and valvular aortic stenosis. The aortic valve was calcified, and velocities and gradients measured by continuous‐wave Doppler met standard criteria for severe aortic stenosis. The increased subvalvular velocities invalidated assumptions of the simplified Bernoulli equation; correction using the longer form of the Bernoulli equation suggested a lower but still significant gradient. The complex shape of the subvalvular spectral Doppler envelope indicated supranormal systolic function and dynamic left ventricular outflow obstruction. Left heart catheterization with an end‐hole catheter was required to determine the subvalvular and valvular components of the obstruction.  相似文献   
107.
108.
109.
110.
A 17‐year‐old boy presented with recurring severe dermatitis of the face of 5‐months duration that resembled impetigo. He had been treated with several courses of antibiotics without improvement. Biopsy showed changes consistent with allergic contact dermatitis and patch testing later revealed sensitization to benzoyl peroxide, which the patient had been using for the treatment of acne vulgaris.  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