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851.
The symptom patterns of 180 women with prospectively confirmed late luteal-phase dysphoric disorder (LLPDD) were examined using a careful application of factor and cluster analytic techniques. Factor analysis of premenstrual change scores on 33 common premenstrual syndrome symptoms yielded four orthogonal factors that were consistent across two sets of menstrual cycle data. These were a negative affect dimension with concomitant behavioral changes, physical symptoms, agitation, and positive arousal. Cluster analysis of factor scores grouped patients into one of five symptom patterns, the most common of which is a general distress cluster, characterized by symptoms across all dimensions. The LLPDD symptom groups identified are remarkably consistent with those of earlier studies using both normative and clinic samples, and consideration of symptom pattern differences in future research may greatly increase our understanding of this disorder.  相似文献   
852.
Evans AS  Frank SJ 《Adolescence》2004,39(153):1-18
Differentiating between additive (quantitative) and interactive (qualitative) effects of comorbidity has important treatment implications. This study illustrates the heuristic superiority of a multifactorial approach over simple group comparisons in testing quantitative versus qualitative models of comorbidity. Analysis of variance was used to compare 266 adolescent inpatients identified as depressed, externalizing, both, or neither on self-report measures of personality, school problems, and substance abuse. The results support quantitative rather than qualitative models of comorbidity. Depressed status related most strongly to group differences in interpersonal and self-critical concerns. Externalizing status related most strongly to group differences in school problems and drug use. Main effects for the two statuses together explained especially elevated levels of reactance and alcohol abuse among the comorbid adolescents.  相似文献   
853.
We have previously shown that during rhythmic passive movement of the index finger, the amplitude of the motor evoke potential (MEP) of the first dorsal interosseous muscle (FDI) as the index finger moved through mid-range adduction, is significantly reduced compared to rest [Edwards, D. J., Thickbroom, G. W., Byrnes, M. L., Ghosh, S., & Mastaglia, F. L. (2002). Reduced corticomotor excitability with passive movement: A study using Transcranial Magnetic Stimulation. Human Movement Science 21, 533-540]. In the present study we have investigated the time-course of this phenomenon. We found that MEP amplitude was significantly reduced at the mid-range position in the first cycle of movement (50+/-6% of resting baseline values), and did not vary across subsequent cycles (10 cycles in 50 s), but that MEP amplitude returned to baseline values within 1s of cessation of movement. The results suggest that the pattern of afferent discharge set up by the kinematics of the movement acting at spinal or supraspinal levels underlies the inhibition observed, rather than an effect of central origin or a cumulative effect of ongoing cyclic movement.  相似文献   
854.
A meta-analysis of the contextual interference effect produced 139 estimates of effect sizes from 61 studies. The average overall effect size was .38. The effect size for basic research (.57) was significantly different from applied research (.19). Significant differences were also obtained between the effect sizes for adults (.50) and those for younger learners (.10). Power for retention and transfer scores was not significantly different. The overall mean power of the studies reviewed was .43.  相似文献   
855.
Adolescent family adversity is a considerable adaptive challenge in an increasingly turbulent developmental period. Using data from a prospective population cohort of 2230 Dutch adolescents, we tested risk-buffering interactions between adolescent family adversity and self-regulation capacities on mental health. We used two adaptive self-regulation capacities that could allow adolescents to manage relatively well with family adversity: (1) parent-reported effortful control, and (2) an attentional flexibility (in this case, set-shifting) task. Adolescent family adversity was associated with internalizing problems and externalizing problems. The risk-buffering effects of effortful control were found for externalizing problems but not for internalizing problems. There were no risk-buffering effects of attentional flexibility on both types of mental health problems. Effortful control is likely to benefit adolescents’ ability to channel their frustrations in adaptive ways in the presence of family adversity. Additionally, (attentional) set-shifting tasks might have a limited predictive value for risk-buffering research.  相似文献   
856.
Signal detection experiments with human observers frequently generate ordinal data which are evaluated using receiver operating characteristic (ROC) methods. These methods may include regressing a continuous two-distribution model to the data set. Because we assume that human observers will not systematically select observations absent the signal, this model should have a monotonic likelihood ratio between the distributions. This paper gives a general method for constructing pairs of distributions that have monotonic likelihood ratios and a possibly large number flexible parameters. It suggests two specific simple parametric forms of monotonic likelihood ratios, constructs new distributions with those likelihood ratios using other standard distributions, and performs ordinal regression with those new distributions to model some example data from the literature.  相似文献   
857.

Objective

This study examined the effects of attachment and temperament on infant distress during venipuncture.

Method

The study was embedded in the Generation R Study, a prospective population-based study. Two different research procedures (i.e., blood sampling and the Ainsworth Strange Situation Procedure) yielded measures of venipuncture distress and attachment security and disorganization in 246 infants aged 14 months. Four temperament traits (distress to limitations, fear, recovery from distress, and sadness) were assessed using the maternally reported Infant Behavior Questionnaire - Revised, at the age of 6 months.

Results

There were no differences between mean levels of distress during venipuncture in infants classified as having insecure attachment, but there was a trend for disorganized attachment. The temperament traits were not related to distress. However, children with a disorganized attachment and higher temperamental fear had more venipuncture distress.

Conclusion

When different risk factors are present simultaneously, infant distress is heightened.  相似文献   
858.

Objective

Variability in infant sleep and negative affective behavior (NAB) is a developmental phenomenon that has long been of interest to researchers and clinicians. However, analyses and delineation of such temporal patterns were often limited to basic statistical approaches, which may prevent adequate identification of meaningful variation within these patterns. Modern statistical procedures such as additive models may detect specific patterns of temporal variation in infant behavior more effectively.

Method

Hundred and twenty-one mothers were asked to record different behaviors of their 4–44 weeks old healthy infants by diaries for three days consecutively. Circadian patterns as well as individual trajectories and day-to-day variability of infant sleep and NAB were modeled with generalized linear models (GLMs) including a linear and quadratic polynomial for time, a GLM with a polynomial of the 8th order, a GLM with a harmonic function, a generalized linear mixed model (GLMM) with a polynomial of the 8th order, a generalized additive model, and a generalized additive mixed model (GAMM).

Results

The semi-parametric model GAMM was found to fit the data of infant sleep better than any other parametric model used. GLMM with a polynomial of the 8th order and GAMM modeled temporal patterns of infant NAB equally well, although the GLMM exhibited a slightly better model fit while GAMM was easier to interpret. Besides the well-known evening clustering in infant NAB we found a significant second peak in NAB around midday that was not affected by the constant decline in the amounts of NAB across the 3-day study period.

Conclusion

Using advanced statistical procedures (GAMM and GLMM) even small variations and phenomena in infant behavior can be reliably detected. Future studies investigating variability and temporal patterns in infant variables may benefit from these statistical approaches.  相似文献   
859.
860.
Using a longitudinal design, this study explored the relation of urban high school student attitudes toward school, work, and self-esteem beliefs to work-based mentoring, mentor satisfaction, and employment status. Participants included high school students taking part in a formal work-based mentoring program, students who established informal mentoring relationships at work, students who worked without a mentor, and students who were not employed during the academic year. While there were no significant group differences in the measures at the start of the year, results at the end of the year showed that students in the formal mentoring program believed more strongly that school was relevant to work than those who worked without a mentor. Students with mentors had higher levels of self-esteem than those who did not work. Students who were highly satisfied with their mentors had higher levels of self-esteem and believed more strongly that school was relevant to the workplace than students who did not work. The implications of these results are discussed and future research areas are identified.  相似文献   
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