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   4707篇
  免费   151篇
  国内免费   2篇
  2020年   70篇
  2019年   63篇
  2018年   132篇
  2017年   117篇
  2016年   122篇
  2015年   79篇
  2014年   78篇
  2013年   393篇
  2012年   161篇
  2011年   141篇
  2010年   87篇
  2009年   99篇
  2008年   113篇
  2007年   124篇
  2006年   111篇
  2005年   103篇
  2004年   100篇
  2003年   72篇
  2002年   84篇
  2001年   134篇
  2000年   104篇
  1999年   90篇
  1998年   50篇
  1997年   44篇
  1996年   53篇
  1993年   52篇
  1992年   73篇
  1991年   80篇
  1990年   66篇
  1989年   70篇
  1988年   74篇
  1987年   68篇
  1986年   60篇
  1985年   73篇
  1984年   70篇
  1983年   58篇
  1982年   59篇
  1981年   49篇
  1979年   68篇
  1978年   72篇
  1977年   61篇
  1976年   59篇
  1975年   69篇
  1974年   66篇
  1973年   61篇
  1972年   55篇
  1971年   56篇
  1968年   54篇
  1967年   64篇
  1966年   49篇
排序方式: 共有4860条查询结果,搜索用时 15 毫秒
191.
In panic disorder bodily sensations appear to play an important role as a trigger for anxiety. In our psychophysiological model of panic attacks we postulate the following vicious circle: individuals with panic attacks perceive even quite small increases in heart rate and interpret these changes as being catastrophic. This elicits anxiety and a further increase in heart rate. To evaluate this model we conducted a field study of 28 subjects with panic attacks and 20 healthy controls. A 24 hr ambulatory ECG was recorded and the subjects were instructed to report any cardiac perceptions during this period and to rate the anxiety elicited by these perceptions. The incidence of cardiac perceptions was about the same in both groups, but only subjects with panic attacks reported anxiety associated with such perceptions. Analysis of the ECGs revealed that in both groups heart rate accelerations preceded cardiac perceptions. Following cardiac perceptions, the healthy controls showed a heart rate deceleration, whereas the subjects with panic attacks had a further acceleration. This heart rate increase after cardiac perceptions was positively related to the level of anxiety elicited by the perceptions. These results provide clear evidence in support of the vicious circle model of panic attacks.  相似文献   
192.
This case study of an inter-university controversy over the publication of research from an interdisciplinary social science project on the forced migration and long-term internment of West Coast Japanese-Americans during World War II shows some of the difficulties of maintaining ownership of research materials. In this particular instance the junior employee was able to override his seniors' demand for control of the dissemination of research results by playing on the concerns about even appearing to suppress work for political reasons. The paper discusses conflicting norms of science and rhetorics of justification ranging from proprietary self-interest through "good science" to "the national interest" and onto "the needs of a free society."  相似文献   
193.
The item characteristic curve (ICC), defining the relation between ability and the probability of choosing a particular option for a test item, can be estimated by using polynomial regression splines. These provide a more flexible family of functions than is given by the three-parameter logistic family. The estimation of spline ICCs is described by maximizing the marginal likelihood formed by integrating ability over a beta prior distribution. Some simulation results compare this approach with the joint estimation of ability and item parameters.IRCAMThe research reported in this paper was supported by Grants APA320 and A4035 from the Natural Sciences and Engineering Research Council of Canada. It was also supported by Contract No. F41689-82-C-10020 from the Air Force Human Resources Laboratory to Educational Testing Service. The author wishes to thank M. Abrahamowicz for his assistance and R. Darrell Bock for providing the parameters for the items used in the simulations.  相似文献   
194.
This study examines the relationship between Type A behaviour and smoking. Data were gathered from a random sample of 100 undergraduate male daily smokers, with a mean age of 21.2 years (SD = 2.72), using the Type A Behaviour Scale (Bortner and Rosenman, 1967). Results reveal that Type A smokers are heavier daily consumers of cigarettes than Type B smokers (t = 2.90, p less than 0.01). The observed relationship between smoking and Type A behaviour remains significant even when the influence of aggression in partialled out. The need to further investigate the interplay of genetic and non-genetic predispositions, and smoking in the incidence of coronary heart diseases (CHD) is suggested.  相似文献   
195.
This experiment provides a test for the common sense knowledge that moderate physical exercise leads to mood improvement. Furthermore, it was tested whether light exercise intensifies negative feeling states or alleviates them. 30 female and 30 male students of psychology served as subjects (mean age 25.3 years, SD = 4.8). After being exposed to a mood induction procedure designed to elicit either a positive or negative feeling state, the subjects had to pedal a bicycle ergometer with 0, 50 or 75 Watt load. Cardiovascular variables and self-reports of mood states were assessed during a baseline period, after the mood induction, following the ergometer exercise, and after a follow-up period. The mood induction procedures were successful, but only for a short duration. Physiological activation was observed according to the ergometer loadings. Moderate physical exercise led to an increase of positive feeling states (Concentration) and a decrease of negative feeling states (Tiredness) in the follow-up period. Corresponding changes in tension related states could not be observed, probably due to the weakness of the mood induction procedure employed and the low level of energetic activation reached.  相似文献   
196.
Dyslexic and normal control subjects memorized simple line patterns inside a grid and subsequently judged whether an "X" would have fallen on the pattern had it been present in an empty grid. The patterns were letters and novel shapes. The grids were presented to the left visual field, to the right visual field, or in central vision. Dyslexic subjects had difficulty generating images of multipart patterns, but this deficit was limited to letters. The findings suggest that dyslexics may have selective difficulty integrating visual information stored in long-term memory.  相似文献   
197.
Potential members of the International Fluency Association (IFA) were polled regarding their fluency interests and perceived priorities for the organization during the year it was founded (in 1990). Results from 201 respondents indicated that a need for the IFA existed among researchers, clinicians, and representatives of self-help organizations for people who stutter. Improving the quality of treatment for those who stutter was considered the highest priority by all three groups. Researchers were of the opinion that the Journal of Fluency Disorders should be of higher quality than it had been in the past, and clinicians were most interested in reviews of new and relevant materials.  相似文献   
198.
This study focused on adult age differences in the characteristics and quantity of elaborations produced during a prose recall task. Young (M = 24.3 years) and older (M = 67.9 years) adults were tested in 3 same-age, same-gender group size conditions: individual, dyad, and tetrad. Elaborations, which are statements not contained in the text but not inconsistent with it, were divided into 2 major categories. Denotative elaborations included statements that were closely related to the text and filled in gaps in the stories. These elaborations were equally produced by young and older adults and were significantly correlated with gist recall performance. Annotative elaborations were evaluative and interpretive comments. These statements were more frequently produced by older adults but were not correlated with recall performance. Young and older adults had different patterns of annotative elaboration production across group size conditions.  相似文献   
199.
200.
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