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   1265篇
  免费   176篇
  国内免费   70篇
  1511篇
  2024年   9篇
  2023年   23篇
  2022年   33篇
  2021年   30篇
  2020年   60篇
  2019年   31篇
  2018年   28篇
  2017年   59篇
  2016年   47篇
  2015年   42篇
  2014年   67篇
  2013年   146篇
  2012年   62篇
  2011年   65篇
  2010年   75篇
  2009年   68篇
  2008年   61篇
  2007年   57篇
  2006年   61篇
  2005年   46篇
  2004年   31篇
  2003年   29篇
  2002年   38篇
  2001年   15篇
  2000年   35篇
  1999年   26篇
  1998年   13篇
  1997年   11篇
  1996年   14篇
  1995年   21篇
  1994年   15篇
  1993年   12篇
  1992年   9篇
  1991年   11篇
  1990年   6篇
  1989年   6篇
  1988年   9篇
  1986年   6篇
  1985年   10篇
  1983年   8篇
  1982年   5篇
  1980年   7篇
  1979年   5篇
  1978年   13篇
  1977年   11篇
  1975年   5篇
  1974年   8篇
  1968年   4篇
  1967年   7篇
  1962年   5篇
排序方式: 共有1511条查询结果,搜索用时 0 毫秒
961.
An algorithm is described to efficiently compute the cumulative distribution and probability density functions of the diffusion process (Ratcliff, 1978) with trial-to-trial variability in mean drift rate, starting point, and residual reaction time. Some, but not all, of the integrals appearing in the model's equations have closed-form solutions, and thus we can avoid computationally expensive numerical approximations. Depending on the number of quadrature nodes used for the remaining numerical integrations, the final algorithm is at least 10 times faster than a classical algorithm using only numerical integration, and the accuracy is slightly higher. Next, we discuss some special cases with an alternative distribution for the residual reaction time or with fewer than three parameters exhibiting trial-to-trial variability.  相似文献   
962.
The right to buy and sell human organs is challenged by the authors within the framework of a broad Christian perspective. Opposition to organ sales is argued in the light of the developing underclass of poor organ donors throughout the world who sell their organs to the rich. Very often neither the donors nor the recipients are fully informed about the medical risks involved in the procedure of organ transplantation.  相似文献   
963.
Leverpress escape/avoidance is an excellent model for assessing coping in rats. Acquisition of the leverpress response is determined by the interstimulus (signal-shock) interval, as well as the type and duration of the aversive event. One factor that has received less research attention is the safety or feedback signal. The safety signal presumably negatively reinforces leverpress responding through fear reduction. Here, we present a parametric manipulation of safety signal length and avoidance performance. All rats were trained with a 60-s tone conditioned stimulus and an intermittent 1-s, 1.0-mA footshock. Training was further accomplished with a 1-, 2-, 4-, or 6-min safety signal. Acquisition of the avoidance response was comparable at all safety signal durations. Rats trained with the shortest safety signal (1 min) exhibited more leverpresses during the safe period, a measure of anxiety. Thus, acquisition of the leverpress avoidance response was efficient regardless of safety signal duration, even though shorter periods were associated with greater anxiety.  相似文献   
964.
ICU的形成与发展   总被引:3,自引:0,他引:3  
危重病医学从简单的监测与护理到当今发展成为较系统的危重病医学理论、一系列先进的监测手段和救治技术,经过了半个多世纪几代人的努力。ICU的建立和发展是现代医学进步的显著标志之一。危重病医学的贡献在于,在积极治疗原发病的基础上,通过先进的生命支持手段,使许多过去认为已无法救治的危重患者得以存活或延长其生存时间。从ICU的形成、危重病医学学科建设、我国ICU队伍的建设到现阶段ICU的发展过程作简要阐述,并着重指出今后ICU发展中面临的任务与挑战,如ICU收治标准、住院费用、病人安全性,旨在促进我国乃至世界范围内ICU可持续健康的发展。  相似文献   
965.
966.
研究中医临床决策,就要以中医理论为基础,以人文精神为核心;从研究决策中存在的问题入手,才能对决策做出正确判断,从而做出、做好正确决策,提出正确的中医临床决策应从理论、经验和悟性;有所为,有所不为;辨病与辨证结合等方面入手.  相似文献   
967.
A random sample of 1033 adults in an Australian community survey completed a form containing the abbreviated Revised Eysenck Personality Questionnaire together with an index of community involvement in a range of secular groups and church attendance. The data indicate that different personality characteristics are associated with church attendance on the one hand and with secular areas of community involvement on the other hand.  相似文献   
968.
国内外知名大学医学教育办学管理模式的比较分析   总被引:1,自引:0,他引:1  
为了探讨适合我国国情的医学教育办学管理模式,对国内外医学教育的历史沿革、组织管理、资金渠道等进行比较、分析,对国内外知名医学院校基本状况进行汇总.结果显示,国内外知名医学院校在行政隶属、管理体制、职责权限、与附属医院关系、资金渠道方面均有较大差别.研究也表明,紧密合作型办学管理模式是适应我国国情的有益尝试.  相似文献   
969.
倪杭英  马剑虹 《应用心理学》2007,13(1):61-64,86
现有的研究表明,学生的英语成绩会受到学习策略、观念和自我效能感的影响.本文在回顾现有研究成果和相关理论的基础上,采用访谈和问卷调查相结合的方法,对高中生的英语成绩、学习策略、观念和自我效能感的关系进行研究,进一步讨论高中生的英语学习策略的影响因素和路径,得出以下结论:一、英语学习策略、学习观念、自我效能感、英语成绩之间的相关显著,英语成绩受认知记忆策略的影响最大;二、最常用的英语学习策略是补偿策略、记忆认知策略和元认知策略;三、影响高中生英语学习策略掌握的主要自我效能感因素为学习能力和挑战心,主要学习观念因素是方法和自信.  相似文献   
970.
One hundred and twenty-eight subjects tried to recall 20 simple sentences that for some subjects were presented in two different voices or were presented from two loudspeakers on different sides of the room. In addition, some subjects were instructed to remember not only the sentences, but also their voice and location attributes. Intentional instructions for location resulted in poorer recall of the sentences, but intentional instructions for voice did not. The voice attribute seemed to be automatically coded under both intentional and incidental instructions for remembering the attribute, whereas the location attribute seemed to require cognitive processing in addition to that required for encoding the meaning of the sentence. A test for clustering by voice in recall was done to determine if the evidence for automatic ceding of voice was merely an artifact resulting from better recall because of organization. However, no clustering was found. The ideas that speaker's voice and sentence meaning were processed in parallel by different hemispheres of the brain and that the connotation of the voice influenced the meaning of each sentence were offered as two possible explanations of the results.  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