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   171927篇
  免费   7694篇
  国内免费   157篇
  2020年   2795篇
  2019年   3453篇
  2018年   3483篇
  2017年   3933篇
  2016年   4629篇
  2015年   3937篇
  2014年   4804篇
  2013年   23506篇
  2012年   4478篇
  2011年   3546篇
  2010年   3826篇
  2009年   4763篇
  2008年   3772篇
  2007年   3269篇
  2006年   3895篇
  2005年   3904篇
  2004年   3431篇
  2003年   3077篇
  2002年   2871篇
  2001年   3078篇
  2000年   2911篇
  1999年   2967篇
  1998年   2803篇
  1997年   2646篇
  1996年   2571篇
  1995年   2401篇
  1994年   2363篇
  1993年   2321篇
  1992年   2506篇
  1991年   2360篇
  1990年   2199篇
  1989年   2155篇
  1988年   2098篇
  1987年   2162篇
  1986年   2149篇
  1985年   2382篇
  1984年   2498篇
  1983年   2264篇
  1982年   2360篇
  1981年   2336篇
  1980年   2163篇
  1979年   2182篇
  1978年   2146篇
  1977年   2148篇
  1976年   1926篇
  1975年   2014篇
  1974年   2053篇
  1973年   1959篇
  1972年   1550篇
  1971年   1512篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
921.
This study reanalyzes kinematically (via film) the pre- and postoperative locomotor behavior of 4 of the 10 monkeys with partial spinal cord lesions (T8) briefly described by Eidelberg, Walden, and Nguyen (1981). The behavior of the remaining 6 monkeys is qualitatively described. The analysis reveals that 5 of the animals initially exhibited unilateral hind limb stepping. Hind and forelimb cycle durations often differed postoperatively; the hind limbs commonly showed increased values, whereas forelimb cycle durations were reduced: ipsilateral interlimb phase values were usually inconsistent. A review of prior studies of primate spinal cord lesions indicates that sparing of the ventrolateral quadrant may not be essential for locomotor recovery (cf. Eidelberg, Walden, & Nguyen, 1981). Furthermore, this review as well as the kinematic analysis indicates that primates with very significant spinal lesions can stilI exhibit locomotor movements. Thus, although the primate's spinal cord seems less able than other mammals' to readily organize locomotor movements (Eidelberg, Walden, & Nguyen, 1981), the total absence of stepping in primates with completely transected cords is unexpected and warrants further research.  相似文献   
922.
This study investigated the independent effects of induced mood on the encoding of persuasive messages and on the assessment of attitude judgments. In Experiment 1, positive or negative mood was induced either before the encoding of a counterattitudinal message or before the assessment of attitude judgments. When mood was induced before message presentation, Ss in a bad mood were more persuaded by strong than by weak arguments, whereas Ss in a good mood were equally persuaded by strong and by weak arguments. When Ss encoded the message in a neutral mood, however, the advantage of strong over weak arguments was more pronounced when Ss were in a good rather than in a bad mood at the time of attitude assessment. In Experiment 2, Ss exposed to a counterattitudinal message composed of either strong or weak arguments formed either a global evaluation or a detailed representation of the message. Positive, negative, or neutral mood was then induced. Ss in a good mood were most likely and Ss in a negative mood least likely to base their reported attitudes on global evaluations.  相似文献   
923.
In previous research, the emotions associated with repressors' memorial representations were found to be more discrete than those associated with nonrepressors'. In each of the 3 experiments reported here, repressive discreteness was apparent in repressors' appraisals of emotional stimuli at the time they were encoded. In 1 experiment, Ss appraised individual facial expressions of emotion. Repressors judged the dominant emotions in these faces as no less intense than did nonrepressors, but they appraised the blend of nondominant emotions as less intense than did nonrepressors. In the remaining 2 experiments, Ss appraised crowds of emotional faces as well as crowds of geometric shapes. In both crowd experiments, the repressive discreteness was evident in appraisals of crowds of emotional faces but not in appraisals of crowds of geometric shapes. The repressive discreteness effect did not appear to reflect a general repressor-nonrepressor difference in the appraisal of stimulus features. Rather, the results suggested that repressive discreteness may be constrained to appraisals of emotions.  相似文献   
924.
We demonstrated the efficacy of using early memory (EM) data to distinguish postdictively criminally dangerous from nondangerous psychiatric patients. Dangerous patients (n = 30) had been adjudicated not criminally responsible (NCR) for felonies, whereas nondangerous psychiatric patients (n = 30) had no convictions for aggressive offenses. Groups were comparable in age, IQ, socioeconomic status (SES), marital status, and diagnoses. Group racial compositions, however, were significantly different. Statistical analyses were thus performed to clarify the potential effect of this racial confound. Overall, 73% of the dangerous and nondangerous patients were accurately classified via a newly developed EM scoring system, the Early Memory Aggressiveness Potential Score System (EMAPSS). Of those classified as dangerous, 15 of 16 (94%) were actually dangerous. The false-positive rate was an impressively low 6%, suggesting EM aggression is highly predictive of dangerousness postdictively.  相似文献   
925.
While looking through laterally displacing prisms, subjects pointed 60 times straight ahead of their nose at a rate of one complete movement every 2 or 3 s, with visual feedback available early in the pointing movement or delayed until the end of the movement. Sagittal pointing was paced such that movement speed covaried with pointing rate. Aftereffect measures (obtained after every 10 pointing trials) showed that when the limb became visible early in a pointing movement, proprioceptive adaptation was greater than visual, but when visual feedback was delayed until the end of the movement, the reverse was true. This effect occurred only with the 3-s pointing rate, however. With the 2-s pointing rate, adaptation was predominately proprioceptive in nature, regardless of feedback availability. Independent of the availability of visual feedback, visual adaptation developed more quickly with 3-s pointing, whereas proprioceptive adaptation developed more rapidly with 2-s pointing. These results are discussed in terms of a model of perceptual-motor organization in which the direction of coordinative (guidance) linkage between eye-head (visual) and hand-head (proprioceptive) systems (and consequently the locus of discordance registration and adaptive recalibration) is determined jointly by pointing rate and feedback availability. An additional effect of pointing rate is to determine the rate of discordant inputs. Maximal adaptive recalibration occurs when the input (pointing) rate matches the time constant of the adaptive encoder in the guided system.  相似文献   
926.
927.
ABSTRACT A taxon is a nonarbitrary class whose existence is conjectured as an empirical question, not a mere semantic convenience. Numerous taxa are known to exist in nature and society (chemical elements, biological species, organic diseases, geological strata, kinds of stars, elementary particles, races, cultures, Mendelizing mental deficiencies, major psychoses, vocations, ideologies, religions). What personality types, if any, occur in the nonpathological population remains to be researched by sophisticated methods, and cannot be settled by fiat or "dimensional" preference. The intuitive concept of taxonicity is to be explicated by a combination of formal-numerical and causal criteria. Taxometric methods should include consistency tests that provide Popperian risk of strong discorroboration. In social science, latent class methods are probably more useful than cluster algorithms.  相似文献   
928.
Developmental and psychoanalytic theorists have focused increasingly on empirically determined early childhood antecedents of adult attachments, with several resulting taxonomic models. This article suggests a theoretically based and clinically based model of attachment consistent with both psychoanalytic and attachment theories, resulting in an integrative taxonomy of four adult attachment styles: dependent, avoidant, hostile, and resistant-ambivalent. These styles reflect behavioral manifestations of dependence and anger, as derived from the interaction of primitive relational drives, defenses, and interpersonal experience. In addition to theoretical construction, brief clinical examples are presented to facilitate discussion of the model.  相似文献   
929.
930.
This article describes the different reactions to emergency warning messages among residents living within a 3-km radius of a hazardous chemical complex and by people living at least 10 km from an industrial site in France, Greece, and the Netherlands. Belief in warning, primary and secondary appraisal, emotional response, and adherence to normal routine were assessed by conducting face-to-face interviews in which a four-phase scenario simulating a credible industrial accident was presented. The results showed that respondents who did not reside in the neighborhood of the hazardous site were, in general, more inclined to trust the warning messages than respondents who resided in the neighborhood were. With the exception of primary appraisal, the warning phases evoked very distinct reactions in the respondents from all three countries with regard to warning belief, secondary appraisal, emotional response, and adherence to normal routine.  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