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   7982篇
  免费   676篇
  国内免费   204篇
耳鼻咽喉   60篇
儿科学   132篇
妇产科学   104篇
基础医学   1363篇
口腔科学   253篇
临床医学   539篇
内科学   842篇
皮肤病学   209篇
神经病学   952篇
特种医学   177篇
外科学   417篇
综合类   1029篇
现状与发展   1篇
预防医学   916篇
眼科学   413篇
药学   461篇
中国医学   707篇
肿瘤学   287篇
  2024年   27篇
  2023年   116篇
  2022年   173篇
  2021年   370篇
  2020年   289篇
  2019年   266篇
  2018年   276篇
  2017年   338篇
  2016年   323篇
  2015年   298篇
  2014年   498篇
  2013年   487篇
  2012年   412篇
  2011年   460篇
  2010年   364篇
  2009年   402篇
  2008年   343篇
  2007年   339篇
  2006年   308篇
  2005年   279篇
  2004年   231篇
  2003年   223篇
  2002年   196篇
  2001年   170篇
  2000年   143篇
  1999年   110篇
  1998年   99篇
  1997年   116篇
  1996年   103篇
  1995年   83篇
  1994年   84篇
  1993年   76篇
  1992年   78篇
  1991年   82篇
  1990年   72篇
  1989年   80篇
  1988年   58篇
  1987年   50篇
  1986年   53篇
  1985年   66篇
  1984年   56篇
  1983年   34篇
  1982年   32篇
  1981年   51篇
  1980年   39篇
  1979年   25篇
  1978年   23篇
  1977年   17篇
  1976年   11篇
  1975年   9篇
排序方式: 共有8862条查询结果,搜索用时 195 毫秒
31.
研究了人工嗅觉在物质识别中的应用,概述了使用模式识别辨别物质气味的基本原理,详细介绍了人工嗅觉系统的硬件设计,算法和软件实现方法,最后使用本系统对不同香气物质进行了识别,取得了较好的结果。  相似文献   
32.
本文报告对32例60岁以上健康老年人预防高粘滞血症的观察结果.经采取综合预防措施六年,血流变学检测表明:全血(比)粘度、血浆(比)粘度、血沉、红细胞压积均低于对照组,统计学处理表明,前三项指标P值均小于0.01,因此达到了对老年人高粘滞血症的预防目的.  相似文献   
33.
对构建特色医院文化的思考   总被引:3,自引:1,他引:2  
李泽平 《中国医院》2002,6(12):10-12
21世纪的医院是文化的医院,21世纪医院的竞争是文化的竞争,谁能构建出具有特色的医院文化,谁就能赢得竞争主动权。构建特色医院文化,核心是形成共同的理想和精神支柱;关键是打造“学习型”医院组织;根本是树立以人为本、诚信求实的服务理念;目标是树立良好的医院形象;基础是加快医院信息化建设。  相似文献   
34.
A system was developed for exposure of unanesthetized mice to airborne chemicals and for continuous measurement of their breathing pattern prior to, during and following exposure. By measuring inspiratory and expiratory airflows (VI and VE), and integration with time to yield tidal volume (VT), we obtained characteristic modifications to the normal breathing pattern. These permitted recognition that a specific portion of the respiratory tract was affected by the selected airborne chemicals. Following recognition, we also quantitated the degree of effect using one specific measurement in each case. An effect on the upper respiratory tract, induced by the sensory irritant, 2-chlorobenzylchloride, was quantitated by measuring a decrease in respiratory frequency. An effect on the conducting airways, induced by the airway constrictor, carbamylcholine, was quantitated by a decrease in VE at the mid-point of VT. An effect at the alveolar level, induced either by the vagal nerve ending stimulant, propranolol, or by the pulmonary irritant, machining fluid G, was quantitated by an increase in the length of a pause induced at the end of expiration. The system is easy to construct and operate and can be used to rapidly evaluate the effects of airborne chemicals on the respiratory tract.  相似文献   
35.
Conflicting results have been obtained concerning the parametric properties of the pattern electroretinogram. These discrepancies may be due to the large amount of variability inherent in recording amplitudes. We have found the variability within a single stimulus condition to be so large (ranging from 30% to 67% of the mean value) that it could mask any underlying spatial frequency tuning. Changing the stimulus conditions failed to significantly reduce the observed variability, although changing recording conditions produced some reduction. The use of a narrower rejection band, a greater number of sweeps, and placement of the reference electrode on the ipsilateral ear (as opposed to the ipsilateral temple) combined to decrease variability of the pattern electroretinogram within a single recording session; however, intersession variability remained high. Therefore one must be careful in evaluating data from this technique, and caution is advised in its clinical use.  相似文献   
36.
两种术式治疗多囊卵巢综合征的远期疗效追踪比较   总被引:1,自引:0,他引:1  
[目的]评价开腹卵巢楔形切除(OWR)和腹腔镜下双侧卵巢电灼开窗术(LOD)两种术式对多囊卵巢综合征(PCOS)的远期疗效.[方法]1981至2001年在我院诊断为PCOS并接受手术治疗的妇女共151例,其中行OWR 61例、LOD 90例,追踪分析两组妇女术后妊娠率、术后妊娠时间的分布及术前后月经模式变化.[结果]两组的临床特征具有可比性,OWR组累积妊娠率84%,LOD组累积妊娠率72%,两组间没有明显差异,绝大部分妊娠发生在术后18个月内;OWR组术后3个月、半年、1年、3年、5年及10年月经规律的妇女所占的比例分别是81.3%、81.3%、77.3%、77.6%、78.9%、85.2%,明显高于术前的31.1%(P值<0.05);LOD组术后3个月、半年、1年、3年、5年及10年月经规律的妇女所占的比例分别是80.6%、63.5%、56.7%、58.0%、57.6%、42.9%,明显高于术前的35.6%(P值<0.05);术后OWR组月经规律妇女占的比例明显高于LOD组(P均<0.05).[结论]两种术式的术后妊娠率相似.OWR比LOD更好、更长远地改善PCOS妇女的月经异常.  相似文献   
37.
Investigation of the Type A Behavior Pattern (TABP) of pre-school children was conducted to determine the influence of the mother-child relationship on the development of TABP. The incidence of TABP was 44.2% (51.7% in boys and 38.7% in girls). The TABP tendency of the boys decreased as the manifest dissension or conflict in the family grew, in marked contrast with the tendency seen in girls, suggesting that conflict in the family can either weaken or reinforce TABP.  相似文献   
38.
All first-time admissions from 1970 to 1986 with obsessive-compulsive neurosis (OCD) (ICD-8 diagnosis number 300.39) or obsessive-compulsive personality disorder (OCPD) (ICD-8 diagnosis number 301.49) were analyzed based on an extract from the nationwide Psychiatric Case Register in Denmark. All patients with secondary diagnoses other than neurotic disorders or personality disorders (including “neuroses characterogenes”) were excluded from the study. A total of 284 patients were first-time admitted with a main diagnosis of OCD during the period. The sex ratio was 0.67 (males/females). A total of 126 were first-time admitted with a diagnosis of OCPD, with a sex ratio of 1.18 (males/females). Seventy-seven percent of the readmitted patients with a first-time diagnosis of OCD kept a diagnosis within the “emotional spectrum” at the last admission. About half kept OCD as a main diagnosis, whereas only 15% shifted to a severe psychiatric diagnosis such as schizophrenia or manic-depressive psychosis. Of the readmitted patients with OCPD. 13% later developed a diagnosis of manic-depressive psychosis.  相似文献   
39.
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   
40.
活动翼矫治器的研制与初步应用   总被引:2,自引:0,他引:2  
陈启锋 《口腔正畸学》2006,13(4):182-186
目的评价活动翼矫治器的设计原理与矫治效能。方法应用活动翼矫治器对588例错畸形病例进行矫治。对2001年~2004年的389例进行研究,分析其疗效、疗程、复诊次数、弓丝使用等情况。结果病例完成时间为4~15个月,平均为8.13个月。复诊次数4~13次,平均7.55次。平均每例上颌使用弓丝1.95根、下颌1.98根。仅11例病例使用口外支抗。结论活动翼矫治器是一种新研发的高效能矫治器,能够明显缩短疗程、减少复诊次数、减少弓丝用量  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