全文获取类型
收费全文 | 25734篇 |
免费 | 847篇 |
国内免费 | 12篇 |
专业分类
26593篇 |
出版年
2019年 | 246篇 |
2018年 | 297篇 |
2017年 | 336篇 |
2016年 | 382篇 |
2015年 | 298篇 |
2014年 | 327篇 |
2013年 | 1833篇 |
2012年 | 630篇 |
2011年 | 643篇 |
2010年 | 406篇 |
2009年 | 421篇 |
2008年 | 600篇 |
2007年 | 542篇 |
2006年 | 481篇 |
2005年 | 477篇 |
2004年 | 443篇 |
2003年 | 448篇 |
2002年 | 466篇 |
2001年 | 685篇 |
2000年 | 674篇 |
1999年 | 469篇 |
1998年 | 244篇 |
1992年 | 467篇 |
1991年 | 452篇 |
1990年 | 457篇 |
1989年 | 458篇 |
1988年 | 408篇 |
1987年 | 420篇 |
1986年 | 445篇 |
1985年 | 482篇 |
1984年 | 410篇 |
1983年 | 376篇 |
1982年 | 271篇 |
1981年 | 314篇 |
1980年 | 243篇 |
1979年 | 439篇 |
1978年 | 317篇 |
1977年 | 286篇 |
1976年 | 274篇 |
1975年 | 409篇 |
1974年 | 459篇 |
1973年 | 484篇 |
1972年 | 410篇 |
1971年 | 403篇 |
1970年 | 378篇 |
1969年 | 401篇 |
1968年 | 493篇 |
1967年 | 476篇 |
1966年 | 453篇 |
1958年 | 252篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
241.
H Intraub S Nicklos 《Journal of experimental psychology. Learning, memory, and cognition》1985,11(2):284-298
Six experiments studied the effect of physical orienting questions (e.g., "Is this angular?") and semantic orienting questions (e.g., "Is this edible?") on memory for unrelated pictures at stimulus durations ranging from 125-2,000 ms. Results ran contrary to the semantic superiority "rule of thumb," which is based primarily on verbal memory experiments. Physical questions were associated with better free recall and cued recall of a diverse set of visual scenes (Experiments 1, 2, and 4). This occurred both when general and highly specific semantic questions were used (Experiments 1 and 2). Similar results were obtained when more simplistic visual stimuli--photographs of single objects--were used (Experiments 5 and 6). As in the case of the semantic superiority effect with words, the physical superiority effect for pictures was eliminated or reversed when the same physical questions were repeated throughout the session (Experiments 4 and 6). Conflicts with results of previous levels of processing experiments with words and nonverbal stimuli (e.g., faces) are explained in terms of the sensory-semantic model (Nelson, Reed, & McEvoy, 1977). Implications for picture memory research and the levels of processing viewpoint are discussed. 相似文献
242.
The present study examined the effects of the sex of the leader, the sex of the rater, and the temporal position of leader performance information on ratings of leader behavior. Male and female subjects listened to an audiotape of a male or female leader and then rated the leader's initiating structure and consideration behaviors. The position of the leader performance information was manipulated by describing the leader as successful before or after raters listened to the audiotape or not presenting raters with the performance information. Analyses indicated that the sex of the leader and/or sex of the rater biased ratings of initiating structure when the performance information was presented after the audiotape and when no leader performance information was presented. Consideration ratings were affected only by the position of the leader performance information. The results are interpreted within a cognitive/implicit sex theory framework. Implications for leadership research are also discussed.Portions of the data analyzed in this study were collected by the second author as part of a master's thesis directed by Joseph A. Sgro. 相似文献
243.
Alternation behavior, spatial discrimination, and reversal disturbances following 6-hydroxydopamine lesions in the nucleus accumbens of the rat 总被引:3,自引:0,他引:3
K Taghzouti A Louilot J P Herman M Le Moal H Simon 《Behavioral and neural biology》1985,44(3):354-363
The effects of dopaminergic depletion of the nucleus accumbens was tested in various behavioral tasks such as alternation, spatial discrimination, and reversal learning, and in an extinction paradigm in a T maze. Animals with lesions showed impairment of spontaneous alternation behavior, disturbances in the acquisition of spatial discrimination, and great difficulty in reversing previously learned habits. In the extinction phase, experimental animals are unable to adjust their behavior, and continue to choose the previously reinforced arm of the T maze. It is suggested that the nucleus accumbens plays an important role in the transition of motivation into action, and that dopamine has a facilitatory influence on the mediation of these processes. 相似文献
244.
245.
246.
247.
An experiment with 42 human Ss used the transswitching procedure to examine tonic stimulus control of phasic and tonic conditioned vasomotor heart rate, and electrodermal reactions. The conditional stimulus (CSs) were photos of angry and friendly human faces, and the unconditional stimulus (US) was a human scream. In one tonic context (blue light), the CSs were paired with the US, in the other context (yellow light), the CSs were presented unpaired. Following acquisition, an extinction series was run with the US omitted during both tonic contexts. Phasic vasomotor and skin conductance reactions differed in the positive and negative tonic segments (stronger in positive). The skin conductance responses also differed during extinction, but the vasomotor responses did not. Tonic differences (following onset of the tonic stimuli) in unelicited skin conductance response frequency, finger pulse volume, and heart rate were also found, although these developed more slowly than the phasic differences. The finger pulse volume tonic difference was greater in extinction than the skin conductance response frequency. There was no effect of the angry-friendly facial expressions, either directly or in interaction with the transswitching effects. The results were interpreted to mean that the transswitching phenomenon is not limited to one another autonomic effector, but is more generalized across the ANS (sympathetic branch). The absence of influence of the facial expressions indicates the relative weakness of the “preparedness” hypothesis in comparison with more influential contextual factors. 相似文献
248.
While many studies have attempted to produce hypertension through the use of various environmental Stressors, few have succeeded in producing chronic elevations in blood pressure beyond levels considered to be borderline hypertensive (140–160 mm Hg systolic). The problem with most studies stems from the use of genetically normotensive animals and the selection of Stressors to which animals readily adapt. A new approach is suggested, which recognizes the role of genetics in human essential hypertension. Animals with one hypertensive parent do not develop spontaneous hypertension but show a more sensitive cardiovascular response to environmental Stressors than animals with normotensive parents. Preliminary studies revealed that animals with a mixed genetic history of hypertension develop spontaneous borderline hypertension. When subjected to shock-shock conflict, these borderline hypertensive rats (BHR) developed permanent hypertension that failed to abate even after a ten-week, shock-free recovery period. The hypertension was accompanied by elevated heart weight to body weight ratios and by significant cardiac pathology. Subsequent work has demonstrated that these animals also become hypertensive when fed a high-sodium diet. Finally, in a series of exercise studies, we found that BHRs subjected to a shock stressor were protected against stress-induced hypertension if they exercised daily. The potential of this model for studies of the mechanisms by which environmental variables produce permanent hypertension is discussed. 相似文献
249.
250.
H K Gediman 《Journal of the American Psychoanalytic Association》1985,33(4):911-935
This paper deals with imposturous tendencies as ubiquitous and heterogeneous. They may enter into neurotic conflict and compromise, and also reflect an ego function disturbance involving multiple, shifting identities and subsequent problems in the subjective sense of reality of the self and objects. Imposture in a person undergoing analysis is, however, not only a function of individual character and psychopathology; it is also a function of certain inevitable requirements of the analytic situation which constitute a "pull" for its emergence. Vulnerable individuals will respond to this pull in revealing ways. Three case summaries illustrate the spectrum of imposturous tendencies. 相似文献