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   2602篇
  免费   45篇
  国内免费   12篇
  2018年   3篇
  2012年   306篇
  2011年   331篇
  2010年   68篇
  2009年   35篇
  2008年   261篇
  2007年   244篇
  2006年   212篇
  2005年   190篇
  2004年   165篇
  2003年   126篇
  2002年   109篇
  2001年   87篇
  2000年   150篇
  1999年   37篇
  1998年   15篇
  1997年   8篇
  1996年   9篇
  1995年   4篇
  1994年   3篇
  1993年   7篇
  1992年   6篇
  1991年   5篇
  1990年   6篇
  1988年   9篇
  1987年   10篇
  1986年   5篇
  1985年   8篇
  1983年   8篇
  1982年   3篇
  1981年   5篇
  1980年   3篇
  1979年   3篇
  1978年   5篇
  1972年   6篇
  1964年   2篇
  1963年   5篇
  1962年   4篇
  1959年   12篇
  1958年   13篇
  1957年   25篇
  1956年   22篇
  1955年   21篇
  1954年   10篇
  1953年   14篇
  1952年   14篇
  1951年   11篇
  1950年   10篇
  1949年   8篇
  1948年   7篇
排序方式: 共有2659条查询结果,搜索用时 31 毫秒
241.
The current studies investigate the effects of homophobic labels on the self-perception of heterosexual males, hypothesizing that when exposed to homophobic epithets, they are motivated to underline their masculinity and claim a distinctly heterosexual identity by taking distance from homosexuals and, to a lesser degree, from women. Heterosexual male participants were subliminally (Study 1) and supraliminally (Study 2) primed either by a homophobic epithet or by a category label, and completed the Traditional Beliefs About Gender and Gender Identity scale. Participants stressed their heterosexual identity, but not their gender distinctiveness, when exposed to homophobic epithets, compared to category labels. Study 2 demonstrated that the relation between the homophobic label and the participants' heterosexual identity was mediated by how negatively they reacted to the antigay label. Heterosexual identity was enhanced in reaction to homophobic labels but not to an equally derogatory label referring to regional identity. Results are discussed within an intergroup framework.  相似文献   
242.
The aim of this study was to examine postural control in children with cerebral palsy performing a bilateral shoulder flexion to grasp a ball from a sitting posture. The participants were 12 typically developing children (control) without cerebral palsy and 12 children with cerebral palsy (CP). We analyzed the effect of ball mass (1 kg and 0.18 kg), postural adjustment (anticipatory, APA, and compensatory, CPA), and groups (control and CP) on the electrical activity of shoulder and trunk muscles with surface electromyography (EMG). Greater mean iEMG was seen in CPA, with heavy ball, and for posterior trunk muscles (p < .05). The children with CP presented the highest EMG and level of co-activation (p < .05). Linear regression indicated a positive relationship between EMG and aging for the control group, whereas that relationship was negative for participants with CP. We suggest that the main postural control strategy in children is based on corrections after the beginning of the movement. The linear relationship between EMG and aging suggests that postural control development is affected by central nervous disease which may lead to an increase in muscle co-activation.  相似文献   
243.
The aim of the study was to train and test support vector machines (SVM) and self-organizing maps (SOM) to correctly classify gait patterns before, during and after complete leg exhaustion by isokinetic leg exercises. Ground reaction forces were derived for 18 gait cycles on 9 adult participants. Immediately before the trials 7–12, participants were required to completely exhaust their calves with the aid of additional weights (44.4 ± 8.8 kg). Data were analyzed using: (a) the time courses directly and (b) only the deviations from each individual’s calculated average gait pattern. On an inter-individual level the person recognition of the gait patterns was 100% realizable. Fatigue recognition was also highly probable at 98.1%. Additionally, applied SOMs allowed an alternative visualization of the development of fatigue in the gait patterns over the progressive fatiguing exercise regimen.  相似文献   
244.
Predictive methods estimating mechanical internal work (Wint, i.e., work to accelerate limbs with respect to BCOM during locomotion) are needed in absence of experimental measurements. A previously proposed model equation predicts such a parameter based upon velocity, stride frequency, duty factor, and a compound critical term (q) accounting for limb geometry and inertial properties. That first predicted Wint estimate (PWint) has been validated only for young males and for a limited number of horses. The present study aimed to extend the comparison between model predictions and experimentally measured Wint (MWint) data on humans with varying gender, age, gait, velocity, and gradient. Seventy healthy subjects (males and females; 7 age groups: 6-65 years) carried out level walking and running on treadmill, at different velocities. Moreover, one of the subject groups (25-35 years) walked and ran also at several uphill/downhill gradients. Reference values of q represent the main important results: (a) males and females have similar q values; (b) q is independent on velocity and gradient. Also, different data filtering depth was found to affect MWint and, indirectly, PWint, thus also the reference q values here obtained (0.08 in level, 0.10 in gradient) suffer a - 20% underestimation with respect to the previous predicting model. Despite of this effect, the close match between MWint and PWint trends indicates that the model equation could be satisfactorily applied, in various locomotion conditions.  相似文献   
245.
Two studies were carried out in order to better understand the role of perceptual and visuo-motor skills in handwriting. Two training programs, visual-haptic (VH) and visual (V), were compared which differed in the way children explored the letters. The results revealed that improvements of VH training on letter recognition and handwriting quality were higher than improvements after V training. We suppose that VH training was more efficient because it improved both perceptual and visuo-motor skills. In the second experiment, in order to investigate the part of each component, we assessed the link between visuo-motor skills, perceptual skills and handwriting. The results showed that only the visuo-motor tasks predict handwriting copying performance. These results are discussed in relation to the respective roles of the perceptual and visuo-motor skills on letter shape learning and handwriting movement execution.  相似文献   
246.
The results of this study are part of an investigation to determine whether the cognitive-emotional process of emotional recognition is deficient as a function of the clinical condition and alexithymia in subjects with somatization. This investigation applied the self-assessment of emotion and used a procedure that minimizes the use of verbal skills and verbal comprehension. The specific goal of this study was to verify whether there were differences in the covariation between alexithymia and self-evaluation of the emotional reaction in clinical and nonclinical subjects. The results of this study highlight the significant differences between clinical and control subjects. There were inverse significant correlations with the affective valence in clinical subjects, whereas in the ratings of the TAS-20 in control subjects, there were direct correlations with activation. In the conclusions, we discuss whether the variability of the results of previous research of the relationship between alexithymia and emotional recognition is a characteristic feature of this relationship or an effect of the different sampling and procedures utilized.  相似文献   
247.
BCI (Brain-Computer Interface) is a system that allows interaction between the human brain and a computer. It is based on analyzing electroencephalographic signals (EEG) and processing them to generate control commands. The study analyzed the possible influence of psychological variables, such as the imaginative kinesthetic capacity and anxiety, in relation to performance in a BCI. All participants (4 male and 19 female students) completed the questionnaires and carried out a session of BCI to control their EEG signals in a virtual setting of a car along a straight road. The group was divided into two subgroups according to their EEG signals or differential responses obtained in the left-right discrimination. Study results showed no significant differences in cognitive variables of imagination or in anxiety. By comparing the degree of participants' BCI control, a new quantitative parameter for comparing performances and making decisions in signal processing was found. The findings, the ongoing research process to refine the control of a BCI, and the interaction of psychological and computer procedures are discussed.  相似文献   
248.
This paper presents two experiments on nutrient-based flavor conditioning with rats as subjects and sucrose as the unconditioned stimulus (US). Experiment 1 was aimed at establishing an optimal control for conditioning, comparing simultaneous and serial presentations of a flavor and the US. The results showed that simultaneous, but not serial training, produced conditioning. Experiment 2 was designed to obtain evidence of summation as an index of both conditioned inhibition and predictive learning. Group Simultaneous received Pavlovian conditioned inhibition training during which flavor A was simultaneously paired with sucrose on excitatory trials (A+), and forming an unreinforced compound with flavor B on inhibitory trials (AB-). An independent excitor for the summation test was also trained by simultaneous pairings with sucrose (C+). In the control group (Blocked), the AB- trials were presented forming a block at the beginning of training to avoid a negative contingency-relationship with sucrose, and flavor A received serial rather than simultaneous pairing with sucrose (A --> +). On the summation test, only in group Simultaneous was consumption of the CB compound lower than that of flavor C alone, suggesting that, during training, flavor A activated an expectancy of the US occurrence.  相似文献   
249.
This paper presents the Spanish version of the Spence Children Anxiety Scale (SCAS), a rating scale for children and adolescents assessing anxiety disorders as they appear in the DSM-IV. SCAS scores were subjected to confirmatory factor analyses in a sample of 1671 children 10 to 17 years old. Results supported the proposed structure of six interrelated scales. This structure is completely invariant (except for means) in boys and girls and across age groups. Overall, girls scored slightly higher than boys. The relationship of SCAS scores with the child's age was nonexistent or very low and negative. The least frequent anxiety problems among children and adolescents were panic attacks and agoraphobia. Problems that most frequently presented extreme high scores were obsessive-compulsive disorder and social phobia. It is concluded that the Spanish version of the SCAS can confidently be used in the assessment of anxiety disorders in children.  相似文献   
250.
This study presents the validation of the Authentic Leadership Questionnaire (ALQ) in a sample of more than 600 Spanish employees. This questionnaire measures four distinct but related substantive components of authentic leadership. These components are: self-awareness, relational transparency, balanced processing, and internalized moral perspective. Structural equation modeling confirmed that the Spanish version of ALQ has high reliability and predictive validity for important leadership outputs such as perceived effectiveness of leadership, followers' extra effort and satisfaction with the leader.  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