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   76212篇
  免费   1307篇
  国内免费   6篇
  77525篇
  2020年   975篇
  2019年   1203篇
  2018年   1441篇
  2017年   1477篇
  2016年   1737篇
  2015年   1228篇
  2014年   1288篇
  2013年   6229篇
  2012年   2326篇
  2011年   2535篇
  2010年   1510篇
  2009年   1494篇
  2008年   2225篇
  2007年   2171篇
  2006年   1923篇
  2005年   1732篇
  2004年   1707篇
  2003年   1590篇
  2002年   1627篇
  2001年   2334篇
  2000年   2250篇
  1999年   1705篇
  1998年   921篇
  1997年   783篇
  1996年   706篇
  1995年   679篇
  1994年   679篇
  1993年   690篇
  1992年   1370篇
  1991年   1286篇
  1990年   1312篇
  1989年   1205篇
  1988年   1154篇
  1987年   1149篇
  1986年   1139篇
  1985年   1220篇
  1984年   949篇
  1983年   841篇
  1982年   684篇
  1979年   990篇
  1978年   747篇
  1975年   901篇
  1974年   939篇
  1973年   906篇
  1972年   823篇
  1971年   724篇
  1969年   706篇
  1968年   842篇
  1967年   818篇
  1966年   752篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
791.
Two studies provided evidence that alcohol's relationship to psychological stress is indirect and is mediated by the allocation of attention. Study 1 found that, as the attentional demands of a distracting activity increased, so did alcohol's reduction of anxiety. Study 2 replicated this effect and found that a highly demanding activity could reduce anxiety even without alcohol. This study further implicated the role of attention in anxiety reduction by demonstrating a relationship between changes in anxiety and response latency to a secondary monitoring task. Finally, in both experiments, intoxicated subjects who did not perform any activity showed an increase in anxiety. From these data, we argue that alcohol affects psychological stress, to an important degree, through its ability, in conjunction with ongoing activity, to affect the amount of attention paid to stressful thoughts.  相似文献   
792.
Screening batteries of standard neuropsychological tests were administered to 2 different samples (Ns = 90 and 167) of male prison inmates. Scores on the revised Psychopathy Checklist were used to divide inmates in each sample into high, moderate, and low psychopathy groups. There were no group differences in test performance in either of the samples, even when the effects of self-reported psychopathology and substance abuse were taken into account. The overall prevalence of both test-specific and global neuropsychological impairment was low and did not vary significantly across the 3 groups. The results provide no support for traditional brain-damage explanations of psychopathy.  相似文献   
793.
This paper discusses the neuroanatomy and pathology of facial expression and findings on the neuroanatomical connections between expressions of the face and speech. The facial musculature is briefly dealt with in terms of its innervation by the facial nerve and its relationship to the soft palate at the peripheral system level. After considering the facial nuclei, the supranuclear innervation of volitional and emotional facial expression is reviewed. Then supranuclear relations between facial movements and some speech organs are considered. Finally, attention is paid to aspects of facial paralysis stemming from peripheral and central origins.  相似文献   
794.
A case study is presented of the treatment of an Arab coed by a Jewish trainee, and a phantom cotherapist using a modified dialectical therapeutic approach. Its effect on the treatment process and outcome, and on the therapist is discussed.  相似文献   
795.
796.
The interrelationships between cigarette, alcohol, and coffee use were examined in 307 U.S. army trainees and 304 U.S. enlisted army personnel. Usage patterns indicated distinct gender differences in this occupational setting. Among women, cigarette use and alcohol consumption were positively correlated; whereas for men, cigarette and coffee use were positively related. For both males and females, alcohol and coffee use were only weakly correlated. As demonstrated in other studies, nonsmokers showed a consistent pattern of abstention from coffee and alcohol or moderate alcohol use.  相似文献   
797.
Because they were participating in a concurrent panel study, 222 older adults had been asked how much help they would expect to receive in a hypothetical emergency before experiencing two separate floods. For the subsample suffering losses or injuries during the floods, Study 1 examined the accuracy of their expectations, as well as possible changes in them, as a result of help actually received. Generally, victims received much less help than they had expected to receive prior to the floods. Preflood expectation of support predicted help from kin, whereas loss and education predicted help from nonkin sources. However, subsequent expectations did not change as a result of the level of help received. Using the total sample, Study 2 examined the broader issue of whether the disaster itself affected subsequent perceptions of support. Flood exposure, as measured at both individual and community levels, was associated with declines in perceptions of support and social participation.  相似文献   
798.
The temporal characteristics of repetitive finger tapping by the left and right hands were examined in two experiments. In the first experiment, interresponse intervals (IRIs) were recorded while right-handed male subjects tapped in synchrony with an auditory timing pulse (the synchronization phase) and then attempted to maintain the same tapping rate without the timing pulses (the continuation phase). The left and right hands performed separately, at four different rates (interpulse intervals of 250, 500, 750, and 1500 ms). There was no asymmetry of the asynchronies of the timing pulses and the associated responses in the synchronization phase or of the IRIs in either phase, but there was an asymmetry of chronization phase or of the IRIs in either phase, but there was an asymmetry in the temporal dispersion of the responses in both phases. in the second experiment, right-handed males tapped separately with each hand at three different speeds: as quickly as possible, at a fast but steady rate, and at a slow rhythmical rate. The speed asymmetry present when tapping as quickly as possible (with the preferred hand tapping more quickly ) was reduced when tapping at the fast steady rate and was absent when tapping at the slow rhythmical rate. The temporal dispersion of the IRIs produced by the nonpreferred hand was greater than the temporal dispersion of those produced by the preferred hand in all speed conditions. These results show smaller temporal dispersion of tapping by the preferred hand in right-handed males under different conditions, including submaximal speeds at which both hands respond at the same rate. This suggests that the motor system controlling the preferred hand in right-handers had more precise timing of response output than that controlling the nonpreferred hand.  相似文献   
799.
Monosynaptic Hoffman reflexes (H reflexes) were recorded from the soleus muscle during the response latency of a warned reaction time (RT) task that required plantarflexion of the foot. The task was done under four conditions of predictability of the response signal (RS), created by the factorial combination of foreperiod duration (1 and 4 s) and variability (fixed and variable). RT varied systematically with RS predictability and was facilitated in conditions that favored prediction of the RS. The response latency was divided into two successive phases by the onset of reflex augmentation: a premotor phase of constant reflex amplitude and a succeeding motor phase marked by progressively increasing reflex amplitude. Reflex augmentation during the motor phase was coupled more closely to the imminent movement than to the preceding signal to respond. The duration of the premotor phase was unaffected by RS predictability, but the duration of the motor phase (like RT) was shorter when the RS was more predictable. The maximum H reflex amplitude reached during the motor phase was greater when the RS was more predictable. The tonic level of H reflex amplitude during the premotor phase was greater in conditions that made prediction of the RS difficult. A second experiment showed that this difference was present throughout the foreperiod. These results suggest that conditions that favor prediction of the RS enhance motor preparation. changes in motor preparation (which affect RT) affect the processes underlying reflex amplitudes in the premotor phase and throughout the preceding foreperiod, in conditions that make prediction of the RS difficult, appear to reflect heightened general arousal.  相似文献   
800.
Two experiments are reported, which examined the relative contributions of preload (resting force level), change of force, and the time taken to achieve the force in determining isometric force variability. The findings showed that change of force is the strongest determiner of peak force variability but that preload and time to peak force have smaller though systematic effects. A formula that predicts peak force variability is proposed, with preload as an additive effect to the ratio between the change of force level and the square root of time to peak force. These findings confirm that these three impulse variables are significant in predicting force variability and that the impact of rate of force on peak force variability is nonlinear.  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