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   8358篇
  免费   425篇
  国内免费   4篇
  8787篇
  2023年   62篇
  2022年   64篇
  2021年   96篇
  2020年   153篇
  2019年   193篇
  2018年   229篇
  2017年   265篇
  2016年   263篇
  2015年   191篇
  2014年   205篇
  2013年   809篇
  2012年   338篇
  2011年   349篇
  2010年   220篇
  2009年   194篇
  2008年   260篇
  2007年   256篇
  2006年   256篇
  2005年   185篇
  2004年   185篇
  2003年   172篇
  2002年   163篇
  2001年   233篇
  2000年   210篇
  1999年   177篇
  1998年   61篇
  1996年   61篇
  1993年   66篇
  1992年   124篇
  1991年   118篇
  1990年   119篇
  1989年   101篇
  1988年   95篇
  1987年   99篇
  1986年   109篇
  1985年   109篇
  1984年   95篇
  1983年   76篇
  1981年   63篇
  1979年   110篇
  1976年   66篇
  1975年   80篇
  1974年   103篇
  1973年   91篇
  1972年   76篇
  1971年   79篇
  1970年   79篇
  1969年   81篇
  1968年   76篇
  1967年   89篇
排序方式: 共有8787条查询结果,搜索用时 0 毫秒
891.
Torsional eye movements are triggered by head tilt and a rotating visual field. We examined whether attention to a misoriented form could also induce torsion. Thirty-six observers viewed an adapting field containing a bright vertical Une, and then they viewed a display that was composed of two misoriented words (one rotated clockwise, the other counterclockwise, by 15°, 30°, or 45°). The subjects were instructed to attend to one of the words. The subjects’ adjustments of a reference line to match the tilt of the afterimage showed that attention to a misoriented word produces torsional eye movement (verified with direct measurements on 4 additional subjects). This eye movement reduces the retinal misorientation of the word by about 1°. The results of this study reinforce the linkage between selective attention and eye movements and may provide a useful tool for dissecting different forms of “mental rotation” and other adjustments in internal reference frames. Apparent-motion displays confirming that the eye rotated in the head may be downloaded from www.psychonomic.org/archive.  相似文献   
892.
In order to promote ongoing quality improvement of not only the Penn State Cancer Genetics Program, but also other cancer risk assessment programs throughout the country, we developed, piloted and conducted a survey to explore patient expectations, experiences, and satisfaction with the cancer genetic counseling process. The comprehensive survey was mailed to 340 eligible patients, 156 (45.9%) of whom returned the completed survey within the allotted time. Responses to closed-ended questions were tallied and open-ended questions were content analyzed. Major findings show that: (1) Patients were seeking cancer-related information and support throughout the cancer risk assessment process and were interested in participating in available research studies; (2) The setting in which patients are seen for cancer risk assessment may pose potential emotional ramifications; (3) Misperceptions regarding insurance discrimination and lack of insurance coverage persist; (4) Patients view the genetic counselor as responsible for updating them about new discoveries. Specific recommendations for cancer genetics programs are included.  相似文献   
893.
This study examines whether or not habituation contributes to the regulation of the inhibition of predatory behavior observed during the "prawn-in-the-tube" training procedure. When presented with prawns that are visible behind glass but untouchable, cuttlefish promptly learn to inhibit their capture attempts. The first three experiments demonstrated that the acquired response in the course of training cannot be dishabituated. The fourth experiment demonstrated that the repeated application of a brief visual prawn stimulus, one that is terminated before the cuttlefish can strike, decreases attack latencies. Taken together, the results of this study establish that habituation does not play a significant role in this learning task. In fact, the present findings strengthen the results of previous studies suggesting that passive avoidance learning contributes to the regulation of the inhibition of predatory behavior.  相似文献   
894.
Previous studies on visual working memory (VWM) have primarily investigated memory for an array presented for a single moment. Here, we examined VWM for two arrays separated by a 1,100-msec interval. We focused on the allocation of VWM capacity to the two arrays as a function of dynamic events inserted between them. During the interval, irrelevant dots moved to form three types of motion: (1) coherent (apparent) motion that connected Arrays 1 and 2, (2) jumpy motion, or (3) coherent motion with two disconnected segments. Results showed that VWM for Array 2’s locations was better than for Array 1’s, especially when the arrays were connected by coherent motion. We suggest that coherent motion between two temporally disparate arrays connects the arrays into a single visual event VWM is then biased toward remembering the more recent state of the event.  相似文献   
895.
The inhibition of predatory behavior observed during the "prawn-in-the-tube" procedure has been extensively used in studies of cuttlefish learning. The present study examines the effect of age on the conditioning of this response in the cuttlefish, Sepia officinalis. Data show that a significant increase in acquisition performance occurs between 15 and 21 days of age. The retention curves in 8- and 15-day-old cuttlefish show a monotonic memory process, presumably reflecting the presence of only short-term memory. In 21-day-old cuttlefish, there are two distinct processes which could be a labile short-term memory, and a subsequent intermediate memory. These mnesic systems seem to become more effective over the course of post-embryonic development. Moreover, the retention curves obtained in the oldest cuttlefish (30- and 90-day-old) bear a close resemblance to that observed in adults. These behavioral findings will allow further work on the cellular and molecular mechanisms of learning and memory in the cuttlefish.  相似文献   
896.
The inhibitor of monoaminooxydase isatin and the ligand of B-receptors cholecystokinin-4 play a significant role in the suppression and induction of depressive and anxiety states. We induced the formation of auto-antibodies to these compounds against their conjugates with antigen-carrier by immunization of white rats. The result was long-term (more than 2 months) stimulation of depressive and anxiety behavior after immunization to isatin and, in contrast, the suppression of such behavior after immunization to cholecystokinin. The perspective of immunochemical approach to long-term correction of behavior is discussed.  相似文献   
897.
This research demonstrates that preference for emotions sometimes cannot be equated with a positive-negative valence dimension. Participants were asked to make choices between pairs of affect-inducing options opposite in valence but equal in activation. The results showed that in absence of contextual cues or situational constraints, choices followed a pleasure-maximizing principle. However, when information was provided about a context cueing appropriateness of certain emotions over others, a preference reversal was observed so that negative emotions were preferred over positive emotions. These results are discussed in relation to current theories of pleasure-maximizing choice and behavior.  相似文献   
898.
In this qualitative study the authors examine the Scriptural images that 10 Lutheran pastors employed in describing the ethical challenges in the pastor-congregant relationship. The analysis of Scriptural images is part of a larger study on pastors' experiences of a mandatory workshop, "Crossing the Boundaries (CTB),"which is required of Evangelical Lutheran Church in Canada (ELCIC) seminarians. The pastors' images were analyzed from the four perspectives of depth psychology, theology, social ethics, and sociology. In commenting on tensions in the pastors' Scriptural images the authors note commonalities among the four theoretical perspectives and discuss implications for practice and future research.  相似文献   
899.
We introduce the Berlin Affective Word List (BAWL) in order to provide researchers with a German database containing both emotional valence and imageability ratings for more than 2,200 German words. The BAWL was cross-validated using a forced choice valence decision task in which two distinct valence categories (negative or positive) had to be assigned to a highly controlled selection of 360 words according to varying emotional content (negative, neutral, or positive). The reaction time (RT) results corroborated the valence categories: Words that had been rated as “neutral” in the norms yielded maximum RTs. The BAWL is intended to help researchers create stimulus materials for a wide range of experiments dealing with the emotional processing of words.  相似文献   
900.
The movements of newborns have been thoroughly studied in terms of reflexes, muscle synergies, leg coordination, and target-directed arm/hand movements. Since these approaches have concentrated mainly on separate accomplishments, there has remained a clear need for more integrated investigations. Here, we report an inquiry in which we explicitly concentrated on taking such a perspective and, additionally, were guided by the methodological concept of home base behavior, which Ilan Golani developed for studies of exploratory behavior in animals. Methods from nonlinear dynamics, such as symbolic dynamics and recurrence plot analyses of kinematic data received from audiovisual newborn recordings, yielded new insights into the spatial and temporal organization of limb movements. In the framework of home base behavior, our approach uncovered a novel reference system of spontaneous newborn movements.  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