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   4556篇
  免费   186篇
  2022年   23篇
  2021年   28篇
  2020年   74篇
  2019年   59篇
  2018年   99篇
  2017年   113篇
  2016年   166篇
  2015年   76篇
  2014年   126篇
  2013年   590篇
  2012年   172篇
  2011年   198篇
  2010年   111篇
  2009年   148篇
  2008年   186篇
  2007年   186篇
  2006年   198篇
  2005年   124篇
  2004年   171篇
  2003年   143篇
  2002年   140篇
  2001年   81篇
  2000年   74篇
  1999年   62篇
  1998年   70篇
  1997年   64篇
  1996年   59篇
  1995年   57篇
  1994年   76篇
  1993年   57篇
  1992年   45篇
  1991年   44篇
  1990年   40篇
  1989年   45篇
  1988年   42篇
  1987年   49篇
  1986年   34篇
  1985年   54篇
  1984年   44篇
  1983年   42篇
  1982年   59篇
  1981年   44篇
  1980年   37篇
  1979年   39篇
  1978年   51篇
  1977年   54篇
  1976年   51篇
  1975年   46篇
  1974年   36篇
  1973年   35篇
排序方式: 共有4742条查询结果,搜索用时 15 毫秒
71.
A critical problem in most real-time programming tasks is the verification that timing of the presented displays and recorded events occur at the expected times. It is often difficult for psychologists to verify critical timing because of the lack of costly specialized tools and technicians to measure events with millisecond accuracy. Algorithms utilized in a new Time Audit mechanism, added to the Micro Experimental Laboratory, are described. This new mechanism involves the recording and time stamping of all input and output events with 0.1-msec accuracy. This allows the experimenter to determine the initiation, duration, and termination of each event and also makes it possible to relate these events to the synchronization of the screen refresh cycle. A customized user interface provides a time log and event-tracing feature that enables nonprogrammers to determine the duration of command execution to the .1-msec level, allowing rapid, precise assessment of program execution. The resulting time log provides a detailed specification of the experimental events for debugging and a permanent record of the experimental procedure.  相似文献   
72.
The relationship between local/global and high/low spatial-frequency processing in hemispheric asymmetries was explored. Subjects were required to judge the orientation of a high- or low-spatial-frequency component of a compound grating presented in the left visual field (LVF) or right visual field (RVF). In Experiment 1, attention was focused on one or the other component. A signal detection analysis indicated that sensitivity (d′) to the high-spatial-frequency target was reduced more by the presence of the low-spatial-frequency component when both were presented in the LVF rather than in the RVF. In Experiment 2, subjects determined whether a target orientation was present, independent of spatial frequency at only a single level (i.e., at the high- or low-spatial-frequency level), as opposed to both or neither level. An RVF/LH (left hemisphere) advantage was found when the decision was based on the orientation of the high-frequency component. The asymmetrical influence of visual field of presentation and spatial frequency upon sensitivity is discussed in terms of hemispheric differences in the magnitude of inhibition between spatial-frequency channels and in the role of transient channel activity to capture and direct higher order attentional processes.  相似文献   
73.
74.
We examined the accuracy of 24 staff members' predictions of activities preferred by 14 individuals with severe disabilities. For each of 144 activities, staff members assigned a client preference rating of “likes a lot,” “likes,” or “dislikes.” Two activities from each category were randomly selected for each individual with disabilities. Pairs of selected activities were presented to the individuals, who were prompted to choose an activity. Staff members' activity preference ratings correctly predicted the choices made by the individuals with disabilities for 78% of the trials. The more divergent the preference ratings of the paired activities, the more likely staff members were to predict correctly the activity selected by a participant.  相似文献   
75.
76.
Requirements for conditioning of an ethanol-mediated taste aversion in 16-day-old rat pups were examined. Experiment 1 demonstrated that preweanling rats are capable of acquiring, in two trials, an aversion to a 15% sucrose solution when followed by intragastric intubation of a 1.2 g/kg dose of 17% v/v ethanol, but not when followed by a 0.4 g/kg dose. Comparison was with control animals given sucrose followed by an equivalent volume isocaloric Half and Half. When the 0.4 g/kg dose of ethanol preceded sucrose presentation by 30 min (Experiment 2), the aversion was learned, suggesting that the effective delay between the sucrose and the critical consequences of the ethanol had been too long with the former procedure. Expression of the sucrose aversion required, however, the reinstatement of the context of intoxication--state-dependent retention. Finally, the results of Experiment 3B indicated that, in addition to the association between the sucrose and the aversive consequences of alcohol intoxication, the orosensory cues resulting from alcohol's direct elimination, via such processes as respiration and salivation, became associated with the appetitive properties of the sucrose. This was evidenced by a conditioned increase in preference for ethanol odor. Possible age-related differences in the ability to associate stimuli with alcohol's unconditioned consequences, and in state dependency are discussed.  相似文献   
77.
Adherence to religiously and culturally defined communities is a complex affair, likely to be misconstrued by those perceiving such communities from the 'outside'. This is a major reason why multiculturalism has failed to deal with the threat posed by religious fundamentalism. In particular, dissenting voices within these communities are marginalized. Fundamentalism is understood here as a specific anti-modern movement, a response to the crisis of rationality that draws on the same emotional forces as do postmodernism and feminism but to different ends. It is characterized by acceptance of the existence of absolute authority, militancy and anti-humanism. It casts women as both 'ideal' (as mothers and bearers of the culture) and 'other' (as sexual subjects). It embodies a failure of the imaginative capacity to tolerate difference and otherness, linking it with other narcissistic responses to the tensions of modernity. Challenging fundamentalism, in therapy and in politics, requires a more subtle understanding of the dynamics of dissent within cultural and religious communities too conveniently characterized by outsiders as homogeneous.  相似文献   
78.
The cellular expression of S-100β protein is upregulated in Alzheimer's disease and in Down's syndrome, and this protein has been implicated in memory-related processes in laboratory animals. However, the possibility that the α subunit of S-100 is also involved in memory has not yet been examined. In the present study, day-old black Australorp white Leghorn cockerel chicks (Gallus domesticus) received injections of monoclonal antisera to S-100α (1:50) or S-100β (1:500) into each hemisphere immediately after training on a one-trial passive avoidance task. The chicks displayed significantly lower retention levels than control birds that had been injected with antisera to carbonic anhydrase, or with saline (p< .01). S-100α antisera had an amnestic effect when injected between 0 and 20 min after training, with memory deficits occurring from 30 min postlearning, at the point of transition between the A and the B phases of the Gibbs-Ng intermediate memory stage. By contrast, the S-100β antisera needed to be injected either 5 min before or immediately after training and produced amnesia 10 min earlier, at the start of the A phase of the intermediate memory stage. We conclude that the two subunits of the S-100 protein are required at different points in the sequence of events leading to the consolidation of passive avoidance memory.  相似文献   
79.
80.
This study of a sample of working women investigated where positive experiences were derived from in everyday life, focusing on the domains of work and nonwork (leisure). It examined how aspects of the situation, in terms of principal environmental influences in work and leisure, and the person, in terms of locus of control, were associated with positive subjective states and psychological well-being. The study employed questionnaires and also the experience sampling method. The results showed that both work and leisure were important for positive psychological states and that internal locus of control was associated with greater enjoyment, interest, feelings of immediate control, intrinsic motivation, life satisfaction, and affective well-being and a number of principal environmental influences.  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