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   5303篇
  免费   523篇
  国内免费   88篇
耳鼻咽喉   135篇
儿科学   198篇
妇产科学   93篇
基础医学   353篇
口腔科学   254篇
临床医学   857篇
内科学   691篇
皮肤病学   133篇
神经病学   459篇
特种医学   69篇
外国民族医学   1篇
外科学   430篇
综合类   418篇
预防医学   1120篇
眼科学   137篇
药学   265篇
  18篇
中国医学   133篇
肿瘤学   150篇
  2024年   21篇
  2023年   125篇
  2022年   208篇
  2021年   294篇
  2020年   262篇
  2019年   243篇
  2018年   243篇
  2017年   263篇
  2016年   200篇
  2015年   211篇
  2014年   326篇
  2013年   476篇
  2012年   279篇
  2011年   329篇
  2010年   246篇
  2009年   275篇
  2008年   283篇
  2007年   279篇
  2006年   222篇
  2005年   185篇
  2004年   129篇
  2003年   119篇
  2002年   105篇
  2001年   89篇
  2000年   75篇
  1999年   59篇
  1998年   53篇
  1997年   52篇
  1996年   41篇
  1995年   27篇
  1994年   31篇
  1993年   19篇
  1992年   26篇
  1991年   21篇
  1990年   15篇
  1989年   13篇
  1988年   11篇
  1987年   8篇
  1986年   4篇
  1985年   9篇
  1984年   8篇
  1983年   6篇
  1982年   2篇
  1981年   2篇
  1980年   6篇
  1979年   3篇
  1978年   4篇
  1977年   2篇
  1976年   2篇
  1966年   1篇
排序方式: 共有5914条查询结果,搜索用时 31 毫秒
31.
This survey evaluated acceptance of the Lightspeed canal preparation (LS) technique by Swiss practitioners. The technique was introduced to Switzerland inJune 1994and 10 other continuing education (CE) courses were held at the Zurich Dental School by July 1995. Acceptance was assessed by posting questionnaires to the CE course attendees. Of the 305 questionnaires posted, 177 (58%) were returned. Of the CE participants 80% had used the technique with 60% finding the method easier and 43% finding it quicker than their usual preparation techniques. Of the respondents 58% used the technique on all tooth types and 76% of the LS users had fractured an instrument at least once. Amongst others, fractures were caused by too much pressure (25%), incorrect insertion angles (17%) and by a complicated root morphology (15%). Fractures occurred high up on the instrument shaft (74%) and near the tip (7%). Working lengths were claimed by 62% to be easier to maintain by LS than their usual preparation techniques. Among the respondents 52% obturated LS prepared canals more easily and quickly compared with their usual preparation techniques. Only 10% of LS users would not recommend the technique, but those who would suggested that proper tuition was necessary to minimize the risk of instrument fracture. The LS technique was positively assessed by clinicians who attended the CE courses in Switzerland where endodontics is not accepted as a speciality  相似文献   
32.
Two hundred and seventy healthy university students were surveyed in December 1995 using Bond's Defense Style Questionnaire (DSQ) to measure the subjects' defense mechanisms. At the same time, a survey using Byrne's R-S Scale (Repression–Sensitization Scale) of the MMPI (Minnesota multiphasic personality inventory) and five psychiatric symptom indexes (anxiety, sense of inadequacy, sensitivity, depression and impulsive anger) selected from the CMI (Cornell Medical Index-Health Questionnaire) was conducted. Three factors were extracted from the DSQ through factor analysis: immature defenses, neurotic defenses, and mature defenses. The results of analysis of variance revealed the following: (i) for anxiety and anxiety related symptoms, both immature defenses and neurotic defenses indicated principal effect; (ii) for impulsive anger and depression, immature defenses presented principal effect; and (iii) for sensitivity and impulsive anger, interaction between a mature defense style and neurotic defense style was noted. The relationship between defense styles and psychiatric symptoms in healthy people is studied in this paper.  相似文献   
33.
目的 编制急诊科(emergency department,ED)护士对新发传染病(emerging infectious diseases,EID)知信行(knowledge attitude practice,KAP)调查问卷,并进行信效度检验。方法 以KAP理论为基础,通过文献回顾、德尔菲专家函询形成问卷初稿;于2021年5月方便抽样上海市3所三级甲等综合医院293名ED护士进行预调查,完成问卷条目筛选和信效度检验。结果 形成含有34个条目的ED护士对EID知信行调查问卷,其中知识维度12个条目、态度维度10个条目、行为维度12个条目。问卷整体Cronbach's α系数为0.926,各维度Cronbach's α系数为0.617~0.968;问卷整体分半信度为0.846,各维度分半信度为0.614~0.958。问卷水平内容效度指数(scale-level content validity index,S-CVI)为0.99,条目水平内容效度指数(item-level content validity index,I-CVI)为0.99~1.00;探索因子分析显示,知识、态度、行为3个维度分别提取公因子4个、1个、2个,累计方差贡献率分别为50.192%、78.319%、73.341%,问卷整体累计方差贡献率67.242%;验证因子分析显示,问卷整体及各维度拟合度较好。结论 EID知信行调查问卷具有良好的信效度,可作为ED护士对EID KAP的评估工具。  相似文献   
34.
A program called “An Epidemiological Approach to Computerized Medical Diagnosis” (AEDMI) is presented. Using an interactive questionnaire, physician-patient interviews are conducted and a summary of the relevant clinical data is provided. Standard items, obained on a multi-centre basis, form a large-scale data base. Simultaneously, the reasoning of clinical experts in each real case is analyzed to obtain a knowledge-rules data base. The methodology of the program combines Bayesian systems, expert systems, and other new lines of researcg such as neural networks or case-based reasoning. The general concepts of clinical decision making aid systems are reviewed. This publication is aimed at obtaining international cooperation.  相似文献   
35.
41名肢残者十六项人格特质测验   总被引:1,自引:1,他引:1  
张丹 《中国心理卫生杂志》1989,3(6):248-249,271
应用“卡特尔十六项人格特质测验问卷”,对41名肢残者和40名健全人进行对照研究。结果表明,肢残人较健全人在孤独性上具有明显的差异,偏于缄默,固执,关注外界信息,具有一定的防卫倾向。肢残人富于实验性,较健全人更自由、激进、好学,具有较强的独立工作能力,希望生活更充实多彩。在各项能力水平上,肢残上与健全人没有显著差别。不同性别肢残人人格特质在敏感性上差异明显,女性较理智和着重现实,而男性则偏于敏感,易感情用事。  相似文献   
36.
BACKGROUND: Asthma is becoming increasingly prevalent and a number of research groups are investigating its genetic and environmental basis. OBJECTIVE: To produce a brief screening tool suitable for determining phenotype in asthma research. METHODS: The scores from eight questions on symptoms and history were obtained from 678 adults and 244 children from high asthma-incidence caucasian families. An independent physician diagnosis was also obtained with the use of a modified NHLBI-CSGA questionnaire and pulmonary function test. Stepwise logistic regression was applied to determine which of the eight questions had greatest predictive value for asthma, and the quality of the resultant models was evaluated using an independent set of 643 adults and 239 children. RESULTS: For adults, the most parsimonious model used responses from three of the eight questions. It had sensitivity and specificity of 0.94 and 0.96, respectively. For children, responses to two questions gave a model with sensitivity and specificity of 0.97. For both age groups, negative predictive values were above 0.87. Positive predictive values were 0.58 and 0.78 for adults and children respectively. The latter emphasize the need for conformation, by physician, of "affected" calls made by this initial screen. CONCLUSION: The brief questionnaires described are potentially useful in a research setting, as a preliminary screening mechanism of low cost. Their use will reduce the numbers of subjects that must undergo detailed phenotyping.  相似文献   
37.
In order to develop a genetic study of human laterality, we conducted an exploratory study concerning one aspect of this phenotype: lattice analysis was used to determine whether the structure of manual preference was the same for right- and left-handers. The study highlights the links between two sets — participants and actions — describing binary data, by ordering them dually along a Galois lattice: participants were ordered according to subsets of actions for which they used only their writing hand, while actions were ordered according to sub-groups using their writing hand to perform them. The twelve item questionnaire of Annett was analysed in two samples of 94 adult right-hand and 31 left-hand writers. The items did not have the same categorical impact for the two groups of left- and right-hand writers. The behaviour of right-handers appeared globally more stereotyped. On the contrary, left-handed profiles were nearly all distinct. To explore these conclusions more thoroughly in the general population would certainly require greater samples. Nevertheless in both cases the observed structures were highly dimensional, a result that would grow stronger as the group sizes increase. Hence whereas some questionnaires purport to evaluate laterality along an unidimensional continuum, the present analysis questions such a strong assumption providing evidence to the contrary.  相似文献   
38.
青少年网络行为问卷的编制及信效度分析   总被引:1,自引:2,他引:1  
目的:编制青少年网络行为问卷,为系统评估网络成瘾青少年的网络相关行为特点提供工具。方法:通过开放式访谈和文献复习,建立问卷的初始条目库。采用探索性因素分析技术筛选条目。在湖南永州和长沙市分别取样490例和606例,进行问卷的有关信效度检验。结果:青少年网络行为问卷最终由56个条目构成,其中反映网络使用时间和上网条件等一般情况的条目16条,余40个条目可归纳为9个因子,分别为信息与技术、性与游戏、娱乐放松、网络人际关系、网络效能感、对网络的积极评价、消极评价、上网焦虑、网络满意度。9因子累计可解释方差变异的51.651%。验证性因素分析表明,9因子结构拟合良好,χ2/df=2.780,NFI=0.961,RFI=0.957,IFI=0.975,TLI=0.972,CFI=0.975,RMSEA=0.054。除少数分量表外,各分量表的"系数和重测相关系数较高。结论:青少年网络行为问卷具有较好的结构效度和信度。其实证效度有待进一步检验。  相似文献   
39.
老化态度问卷的编制及其初步试用   总被引:5,自引:0,他引:5  
目的:编制老化态度问卷。方法:通过调查和参考国外量表,组成问卷。在老年人中使用后,对问卷进行各项量表属性分析。结果:根据项目分析结果。对条目筛选后的老化态度问卷,因此分析显示具有两个主成分。内部一致性信度和复测信度达到0.9以上。分半信度0.77。结论:自编老化态度问卷具有良好信度,效度。  相似文献   
40.
The Pain Catastrophizing Scale (PCS; Sullivan et al., Psychol. Assess. 7, 524–532, 1995) has recently been developed to assess three components of catastrophizing: rumination, magnification, and helplessness. We conducted three studies to evaluate the factor structure, reliability, and validity of the PCS. In Study I, we conducted principal-components analysis with oblique rotation to replicate the three factors of the PCS. Gender differences on the original PCS subscales were also analyzed. In Study II, we conducted confirmatory factor analyses to evaluate the adequacy of fit of four alternative models. We also evaluated evidence for concurrent and discriminant validity. In Study III, we evaluated the ability of the PCS and subscales to differentiate between the responses of clinic (students seeking treatment) and nonclinic undergraduate samples. Also, in the clinic sample, we evaluated evidence of concurrent and predictive validity for the PCS. The internal consistency reliability indices for the total PCS and subscales were examined in all three studies. Limitations and future directions are discussed.  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