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   6354篇
  免费   260篇
  国内免费   4篇
  2020年   83篇
  2019年   110篇
  2018年   163篇
  2017年   155篇
  2016年   161篇
  2015年   126篇
  2014年   150篇
  2013年   671篇
  2012年   233篇
  2011年   254篇
  2010年   145篇
  2009年   148篇
  2008年   219篇
  2007年   203篇
  2006年   225篇
  2005年   179篇
  2004年   163篇
  2003年   172篇
  2002年   197篇
  2001年   138篇
  2000年   135篇
  1999年   128篇
  1998年   94篇
  1997年   78篇
  1996年   100篇
  1995年   81篇
  1994年   80篇
  1993年   77篇
  1992年   81篇
  1991年   87篇
  1990年   83篇
  1989年   85篇
  1988年   72篇
  1987年   78篇
  1986年   78篇
  1985年   82篇
  1984年   80篇
  1983年   72篇
  1982年   89篇
  1981年   77篇
  1980年   62篇
  1979年   83篇
  1978年   68篇
  1977年   61篇
  1976年   69篇
  1975年   63篇
  1974年   56篇
  1973年   50篇
  1970年   54篇
  1967年   52篇
排序方式: 共有6618条查询结果,搜索用时 15 毫秒
51.
The Jenkins Activity Survey (JAS) and the Framingham Type A Scale (FTAS) have been found to have different psychological correlates. The JAS is typically unrelated to anxiety, while the FTAS is consistently correlated with trait anxiety. The present study of 200 male and female college students clarifies further the psychological heterogeneity of these measures. Enhanced motivation to control the environment has been suggested as an underlying psychological component of Type A behavior (Glass, 1977). Dysphoric emotions and the perception of more environmental stresses, on the other hand, are typical of neuroticism or negative affectivity (Watson & Clark, 1984). Although the results indicate that the JAS and FTAS are highly correlated, the JAS is more closely related to control motivation than is the FTAS. Further, compared to the JAS, the FTAS is more closely correlated with dysphoric emotions and perceived daily stresses. Thus, the results indicate that the JAS is closely correlated with core psychological components of the Type A pattern, while the FTAS has a relatively unique association with general emotional distress. Such differences may account for the fact that these measures are related to different disease end points.  相似文献   
52.
In our research, the data are gathered in the laboratory on a DEC PDP-11/24 minicomputer. Once the data are gathered, they are analog-to-digital (A/D) converted and sent by the PDP to an IBM 370-3031. The data are submitted to a Fast Fourier Transform (FFT) on the IBM computer. Once the FFT is completed, the data are accessed by an IBM PC-XT that is equipped with an IRMA system. The PC is used in its emulation mode to access the data in the mainframe. In the mainframe, SPSS or SAS is used to do the initial statistical analyses. When necessary, subsets of the data are transferred to the PC, where other computer programs are used to analyze the data. In many instances, they are returned to the mainframe from the PC, where they are submitted to multivariate statistical analysis. Finally, all of the data are stored on floppy disks, which are prepared on the PC.  相似文献   
53.
54.
The role played by reflex pathways in the production of movement has been a significant issue for motor control theorists interested in a wide variety of motor behaviors. From studies of locomotion and chewing, it appears that gains in reflex pathways can be altered so that activity in these pathways does not produce destabilizing responses during movement. In speech production, recent experimental evidence has been interpreted to suggest that autogenetic lip reflexes (perioral reflexes) are suppressed during sustained phonation or speech production. The present study was conducted to assess the effects of phonation, direction of movement, and ongoing speech production on reflex responses of lip muscles. The present results suggest, in contrast to earlier work, that this reflex pathway is not suppressed or absent because the amplitude of the observed response depends upon the activation levels of the various muscles of the lower lip and, therefore, indirectly on the nature of the gesture the subject is instructed to produce.  相似文献   
55.
We tested the hypothesis that socially anxious or shy individuals use their anxiety symptoms as a strategy to control attributions made about their performances in social-evaluative settings (i.e., self-handicapping strategies). Specifically, we predicted that trait-socially anxious or shy persons would report more symptoms of social anxiety in an evaluative setting in which anxiety or shyness could serve as an excuse for poor performance than would individuals in (a) an evaluative setting in which shyness was precluded as an excuse or (b) a nonevaluative setting. Furthermore, we predicted that this self-protective pattern of symptom reporting would not occur for individuals who were not trait-socially anxious because these persons would not commonly use such symptoms as a self-handicapping strategy. Results supported these predictions for male subjects, but not for female subjects. Sex differences in the strategic use of shyness are discussed in relation to other research on sex differences in the etiology and correlates of social anxiety.  相似文献   
56.
Three-way metric unfolding via alternating weighted least squares   总被引:6,自引:3,他引:3  
Three-way unfolding was developed by DeSarbo (1978) and reported in DeSarbo and Carroll (1980, 1981) as a new model to accommodate the analysis of two-mode three-way data (e.g., nonsymmetric proximities for stimulus objects collected over time) and three-mode, three-way data (e.g., subjects rendering preference judgments for various stimuli in different usage occasions or situations). This paper presents a revised objective function and new algorithm which attempt to prevent the common type of degenerate solutions encountered in typical unfolding analysis. We begin with an introduction of the problem and a review of three-way unfolding. The three-way unfolding model, weighted objective function, and new algorithm are presented. Monte Carlo work via a fractional factorial experimental design is described investigating the effect of several data and model factors on overall algorithm performance. Finally, three applications of the methodology are reported illustrating the flexibility and robustness of the procedure.We wish to thank the editor and reviewers for their insightful comments.  相似文献   
57.
Rats were used to determine whether stress-induced analgesia (SIA) can be produced by conditioning with interoceptive stimuli (LiCl) as with exteroceptive stimuli (footshock). SIA was measured using a tail-flick test. As expected, unavoidable footshock as well as conditioning with footshock produced SIA. In contrast, conditioning with LiCl failed to cause SIA. The findings support the notion of functional differences in neural substrates for conditioning by exteroceptive and interoceptive cue.  相似文献   
58.
The present experiments examined the effects of self-focus, as produced by focusing on feelings, on memory. In an initial experiment subjects did complex mental arithmetic significantly faster after self-focus. Because complex mental addition involves internally generated stimuli, the remaining experiments compared the effects, on memory, of self-focus on internally generated stimuli to the effect of self-focus on stimuli supplied by the experimenter. In a second experiment, self-focus facilitated memory for digits recalled in reverse order but not for digits when recalled in the given order. In a third experiment, self-focus facilitated the memory for the classification of digits but not for the digits themselves. In a fourth and fifth experiment, self-focus aided memory for classification of objects into categories such as small, medium, or large but did not aid memory for the objects themselves. In general, improved performance due to feeling focus was attributed to the role that self-focus may play in increasing attention to internally generated stimuli.  相似文献   
59.
In the context of an annual fundraising drive for the American Society, two field experiments were conducted to test the relative effectiveness of suggesting either small or large contributions. In experiment 1, as part of a door-to-door campaign 300 people were randomly assigned to: (a) a standard request for contributions (control); (b) the standard request plus the words, “even a penny will help”; or (c) the standard request plus the words, “a generous contribution would really help.” As hypothesized, asking for a generous contribution significantly decreased the percentage of people who donated and failed to increase the average size of contribution by those who gave. Inconsistent with previous findings, the even-a-penny condition did not increase donating. In the second experiment conceptually similar requests were made in a mail-out campaign: 6,000 requests were made—2,000 suggested relatively small amounts (options beginning at $5); 2,000 suggested large amounts (options beginning at $5); and 2,000 were unspecified with regard to recommended amount (control). As expected, compared to the control condition, asking for small amounts increased the proportion of donors to nondonors without decreasing the average size of contributions, while asking for large amounts decreased the proportion of donors to nondonors without increasing the size of contributions. It is suggested that the findings have important implications for charitable fundraising.  相似文献   
60.
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