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   12024篇
  免费   860篇
  国内免费   456篇
耳鼻咽喉   228篇
儿科学   147篇
妇产科学   32篇
基础医学   2374篇
口腔科学   157篇
临床医学   840篇
内科学   774篇
皮肤病学   94篇
神经病学   2115篇
特种医学   1015篇
外科学   448篇
综合类   1236篇
预防医学   978篇
眼科学   253篇
药学   730篇
  3篇
中国医学   1738篇
肿瘤学   178篇
  2024年   62篇
  2023年   189篇
  2022年   377篇
  2021年   490篇
  2020年   381篇
  2019年   324篇
  2018年   321篇
  2017年   384篇
  2016年   395篇
  2015年   410篇
  2014年   666篇
  2013年   973篇
  2012年   665篇
  2011年   783篇
  2010年   591篇
  2009年   584篇
  2008年   649篇
  2007年   571篇
  2006年   553篇
  2005年   484篇
  2004年   415篇
  2003年   340篇
  2002年   329篇
  2001年   255篇
  2000年   230篇
  1999年   188篇
  1998年   173篇
  1997年   170篇
  1996年   149篇
  1995年   164篇
  1994年   155篇
  1993年   150篇
  1992年   102篇
  1991年   115篇
  1990年   68篇
  1989年   77篇
  1988年   61篇
  1987年   49篇
  1986年   39篇
  1985年   50篇
  1984年   37篇
  1983年   32篇
  1982年   27篇
  1981年   20篇
  1980年   24篇
  1979年   15篇
  1977年   12篇
  1976年   9篇
  1974年   8篇
  1973年   9篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
61.
Semantic priming effects (behavioral and electrophysiological) were compared in the visual and auditory modalities across three stimulus onset asynchronies (SOAs; 0, 200, and 800 ms). When both prime and target were presented in the visual modality (the prime just to the left of a fixation point and the target to the right) there were N400 priming effects present across the three SOAs. However, the N400 in the 0-ms SOA condition extended longer in time (800 vs. 500 ms) than in the other SOAs. When both the prime and target were presented in the auditory modality (the prime to the right ear and the target to the left), the largest priming effects were found for the 800-ms SOA. Moreover, there was a relatively early priming effect present in the 0- and 800-ms SOA conditions but not in the 200-ms condition. The results are discussed in terms of modality differences in the time course of word comprehension processes.  相似文献   
62.
Seventy-three men and 72 women made lexical decisions to target words that followed sentences constructed so that the last word was a sexual double-entendre. Prime target relatedness, erotic versus nonerotic target, stimulus onset asynchrony, and participant's gender were varied in a between-subjects design. A second analysis that substituted sentence context for prime target relationship also was conducted. Data were collected on the emotionality and social acceptability of priming sentences and target words. Results revealed that, as with previous research on neutral words, prime target relatedness facilitated lexical decisions. Additionally, there was evidence of slowing in making lexical decisions when erotic material was presented or was part of a contextual bias. This delay was accentuated in women. A model that proposes that sexual words evoke a more complex processing sequence is presented. The model suggests that appraisal and checking or editing mechanisms, which are accentuated in women, help explain the phenomenon. Portions of this work was submitted by the junior author in partial fulfillment of the requirements for Honors in Psychology at Louisiana State University  相似文献   
63.
This communication concerns a derivation and study of necessary optimality conditions for production scheduling. The continuous-time optimal control problem is stated for the analysis of extremal behaviour of a flexible flow shop. This is accomplished by means of the maximum principle, which is applied to the problem with irregular constraints and three typical forms of objective function.  相似文献   
64.
This study investigated preferential encoding of threat material in subjects with posttraumatic stress disorder (PTSD) with a modified dot-probe paradigm. This paradigm indexes attentional bias by measuring response latency to name neutral target words that are presented adjacent to or distant from threat words. Motor vehicle accident survivors with PTSD (n = 15), subclinical PTSD (n = 15), and low anxiety (n = 15) were required to name target words that were presented either adjacent to or distant from strong threat, mild threat, positive, and neutral words. PTSD subjects named targets faster when they were in close proximity to mild threat words. Results suggested that PTSD subjects' attention was drawn to the mild threat stimuli and are discussed in the context of network models of PTSD.  相似文献   
65.
This study explored whether benzodiazepines selectively affect aspects of attention and/or visual information processing, as they do memory. A cued visual-search paradigm was employed, using normal volunteers and a single dose of triazolam. This paradigm provided for a detailed examination of two aspects of visual attention and information processing: 1) controlled versus automatic attention allocation (via central and peripheral cues), and 2) the extent to which processing an item in a non-cued location affects performance (via cue-validity). Triazolam, compared to placebo, significantly increased response time, and Drug Condition interacted with Cue-Validity but not Cue-Type. Based on these data, we argue that triazolam doesnot affect attention allocation butdoes affect attentional disengagement and/or attention switching mechanisms.  相似文献   
66.
目的:探讨喉部CT仿真内窥镜(CT virtual endoscopy,CTVE)的成像质量及其影响因素。方法:对84例喉部螺旋CT扫描者行CTVE成像,根据喉腔内部结构、病灶、黏膜皱襞的显示情况和有无伪影将CTVE图像分为3级,分别比较CTVE技术在不同的扫描层厚、重建层厚及阈值的情况下图像质量的优劣。结果:CT原始扫描层厚为2mm、3mm分别与5mm、8mm的CTVE图像质量相比较,有显著性差异(P<0.05);重建层厚为2mm、3mm与5mm相比较,均有显著性差异(P<0.05);阈值为 -800— -600HU与阈值为-300HU相比较,有显著性差异(P<0.05)。结论:不同的CT原始扫描层厚、重建层厚及阈值对CTVE图像的质量影响有明显差异。选用合适的原始扫描参数及重建参数,可以提高CTVE图像的质量,对喉部疾病的诊断很有帮助。  相似文献   
67.
中医舌象计算机识别研究的现状分析   总被引:5,自引:1,他引:4  
从静态舌图像计算机识别研究的关键环节出发,对当前的研究现状进行了分析.认为在舌图像的采集方面有必要引入正交设计、图像质量评价等方法以筛选出高标准、统一、实用的图像采集条件;图像分割研究可以考虑从多角度入手,综合使用多种分割方法,取长补短,以提高分割效果;同时采用Delphi评价法、多中心的网上专家判别等手段,大样本集中专家经验,综合各家的辨舌经验,建立科学规范的舌象诊断标准;当前舌象识别研究的热点主要集中在舌的颜色领域,研究的方向有待向颜色以外的其他方面拓展,并最终由定性向定量转化,而实现舌诊内容的综合判别将是今后努力的方向.  相似文献   
68.
解毒降浊、益气活瘀是治疗老年缺血性卒中的主要治则   总被引:2,自引:0,他引:2  
老年缺血性卒中在病因病机、治疗方法等方面迥异于老年前期缺血性卒中患者。根据老年人的生理病理特点结合临床实际,认为正虚血瘀为本,浊毒内蕴为标,毒损脑络为老年脑缺血损伤的终结;正虚血瘀、浊毒内蕴是老年脑缺血损伤的根本原因;解毒降浊、益气活血是治疗老年缺血性卒中的重要方法之一。  相似文献   
69.
70.
改进了传统的云纹数据处理方法,提出用曲面拟合方法处理云纹数据,提高了计算机处理云纹数据的效率与质量。又提出用云纹法测量J积分的技术,可望解决实际工程构件的J积分测量问题。  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