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   36371篇
  免费   1318篇
  国内免费   11篇
  2018年   552篇
  2017年   494篇
  2016年   579篇
  2015年   414篇
  2014年   499篇
  2013年   3412篇
  2012年   866篇
  2011年   898篇
  2010年   583篇
  2009年   556篇
  2008年   864篇
  2007年   766篇
  2006年   724篇
  2005年   600篇
  2004年   584篇
  2003年   613篇
  2002年   587篇
  2001年   1175篇
  2000年   1128篇
  1999年   861篇
  1996年   491篇
  1995年   466篇
  1994年   461篇
  1993年   432篇
  1992年   907篇
  1991年   802篇
  1990年   805篇
  1989年   709篇
  1988年   718篇
  1987年   699篇
  1986年   695篇
  1985年   678篇
  1984年   603篇
  1983年   506篇
  1982年   395篇
  1981年   410篇
  1980年   381篇
  1979年   574篇
  1978年   428篇
  1976年   388篇
  1975年   531篇
  1974年   524篇
  1973年   586篇
  1972年   561篇
  1971年   502篇
  1970年   442篇
  1969年   425篇
  1968年   537篇
  1967年   459篇
  1966年   449篇
排序方式: 共有10000条查询结果,搜索用时 927 毫秒
821.
In this paper, we discuss the importance and problems of data transfer in psychological research environments. Discussion includes how simple text file transfer systems meet researchers’ needs. The systems’ shortcomings are also analyzed. Strategies for customizing systems, using pre-prepared software packages, point-to-point systems, and “networked” systems, are carefully analyzed.  相似文献   
822.
This paper describes a simple infrared photocell circuit that is inexpensive and easy to construct. The light source and detector are housed inexpensively and are focused so the light and detector may be separated over significant distances. The circuit may be used in a variety of conditions, including total darkness and bright fluorescent lighting, without having to readjust or recalibrate the circuitry. Output from the circuit may be used to drive other transistors or electromechanical relays. With minimal additional circuitry and hardware the signal may be interfaced with an Apple computer.  相似文献   
823.
RSCORE-J, a computer program for a signal-detection analysis of pooled rating-method data, is listed and described. RSCORE-J computes jackknife estimates of ROC parameters and their standard errors from rating-method data pooled over a group of observers.  相似文献   
824.
A method of hardware reaction timing with millisecond accuracy, using one of the Amiga’s CIA 8520 chips, is described. The registers of this chip can be set to enable cascaded timing that functions independently of the CPU and, thereby, avoids the problems of software timing in a multitasking environment. In addition, the interfacing of a pair of reaction-time keys to one of the Amiga’s game controller connectors and a program for polling this port for keypresses are described.  相似文献   
825.
Forty normotensive subjects participated on a voluntary basis in a study designed to compare the effect of suggestions on blood pressure (BP). Two experimental groups received suggestions presumed to be specific in lowering or raising BP after simple relaxation (relaxation group) or hypnotic induction (hypnotic group). A control group was used to record the BP changes over time. The time variable was significant for both systolic (SBP) and diastolic blood pressure (DBP). Induction procedures (hypnosis or relaxation) resulted in significant decreases in DBP in both experimental groups. In the control group there was a significant decrease in SBP. A specific suggestion to increase the BP resulted only in DBP increase in the hypnotic group. This group also gave an increase of both SBP and DBP over the entire experiment, whereas the relaxation group resulted in a significant decrease in SBP. There was no significant group variable, indicating no differences between the groups. Further research is needed to enable firm conclusions of the effect of suggestions on BP.  相似文献   
826.
This study evaluated the relative efficacy of long (1 minute) and short (15 seconds) durations of negative practice for reducing self-stimulatory leg pounding of a traumatically brain-injured adult. In individual social skill training classes, long negative practice and short negative practice were administered concurrently in an alternating treatments design. Generalization of treatment effects outside of training sessions was assessed during the client's lunch period. The results revealed that both durations of negative practice were equally effective in reducing leg pounding during training sessions. However, the effects of training did not generalize to settings in which the practice contingency was not enforced. Pounding was more frequent and negative practice somewhat less effective during periods of high social stimulation.  相似文献   
827.
828.
829.
The concepts of informed consent and surveillance of human research designed to protect human subjects is commendable. The regulations of the Institutional Review Board (IRB) are having a major impact on clinical cancer research. There is greater administrative time needed of the investigator, the mechanisms of patient care have become cumbersome and some patients reject optional medical management that could be life saving. IRB regulations must be flexible to meet the needs of human subjects as well as those of the clinical investigator.  相似文献   
830.
This article describes three kinds of information constraints in medical encounters that have not been discussed at length in the medical ethics literature: constraints from the concept of a disease, from the diffusion of medical innovation, and from withholding information. It describes how these limit the reliance rational people can justifiably put in their doctors, and even the reliance doctors can have on their own advice. It notes the implications of these constraints for the value of informed consent, identifies several procedural steps that could increase the value of the latter and improve diffusion of innovation, and argues that recognition of these constraints should lead us to devise protections which intrude on but can improve these encounters.  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