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   1014篇
  免费   285篇
  国内免费   88篇
  2024年   3篇
  2023年   21篇
  2022年   15篇
  2021年   44篇
  2020年   33篇
  2019年   86篇
  2018年   101篇
  2017年   120篇
  2016年   83篇
  2015年   69篇
  2014年   46篇
  2013年   110篇
  2012年   34篇
  2011年   44篇
  2010年   29篇
  2009年   45篇
  2008年   51篇
  2007年   40篇
  2006年   31篇
  2005年   29篇
  2004年   23篇
  2003年   18篇
  2002年   14篇
  2001年   14篇
  2000年   7篇
  1999年   9篇
  1998年   7篇
  1997年   7篇
  1996年   4篇
  1995年   5篇
  1994年   2篇
  1993年   3篇
  1992年   3篇
  1991年   6篇
  1989年   1篇
  1988年   2篇
  1986年   1篇
  1985年   27篇
  1984年   21篇
  1983年   25篇
  1982年   29篇
  1981年   19篇
  1980年   21篇
  1979年   28篇
  1978年   10篇
  1977年   15篇
  1976年   16篇
  1975年   9篇
  1974年   5篇
  1973年   2篇
排序方式: 共有1387条查询结果,搜索用时 15 毫秒
11.
ObjectivesThe aim of this study was to compare three different modes of an acute bout of exercise – endurance, strength, and coordination – in their effects on adolescents' attention.DesignThis was a preregistered, prospective, randomized intervention study with four groups and two distinct measurement occasions.MethodEighty adolescent students aged 15–18 years were randomized to one of three exercise intervention groups (endurance, strength, coordination) or to a non-exercise, control group. The exercise interventions lasted for 25 min. The random assignment to the study groups was stratified according to participants' age and gender. Before and after the exercise intervention, all participants completed the revised d2-test of attention. A 4 × 2 repeated measures ANOVA with contrast-coded test was used as the main analysis method.ResultsAttentional test performance increased from before to after the exercise intervention for all exercise groups, as compared with the control group. The three exercise groups improved equally and did not differ in their attentional scores after the intervention.ConclusionsAn acute bout of exercise was in general beneficial for adolescent students' attention, while the mode of the provided exercise training was not decisive. School directors and teachers are encouraged to incorporate exercise-related breaks into their school plan.  相似文献   
12.
LGBTQI2S+ (lesbian, gay, bisexual, transgender, questioning, intersex, and two-spirit, etc.) individuals face unique challenges to physical activity participation, such as discrimination and exclusion. Square dance is a form of collaborative group dancing and while traditionally a heteronormative form of dance, gay square dance is typically open to everyone, regardless of sexual orientation. Square dancing offers opportunities to belong to a community of others engaged in the same activity, which older adults often find satisfying. The aim of this research was to understand how older adults who identify as women experience social support in the context of participating in gay square dance and the role previous experiences of social exclusion play in influencing these experiences. Fourteen self-identified women (age range 55–79 years; n = 11 White, n = 1 Black, n = 2 Jewish) belonging to a gay square dance club participated. Participants self-identified as heterosexual (n = 7), lesbian (n = 3), pansexual (n = 1), bisexual (n = 1), or did not identify with existing terminology (n = 2). Interviews were conducted during a gay square-dancing festival and thematically analyzed. Findings highlighted that participants experienced acceptance which affirmed their sense of self and enabled their authentic selves. To foster a sense of belonging and close relationships, specific actions (e.g., demonstrative welcoming of newcomers, mutual support) were taken by other participants in the group. Physical touch is an inherent part of square dancing, which took on different meanings for participants and was overall perceived as safe. Inclusive groups like gay square dance clubs are an important and consistent means where older adult women can experience meaningful social relationships and interactions.  相似文献   
13.
Cognitive impairment in schizophrenia and other psychiatric disorders is a challenge to be overcome in order to maintain patients' quality of life and social function. The neurological pathogenesis of cognitive impairment requires further elucidation. In general, the hippocampus interacts between the cortical and subcortical areas for information processing and consolidation and has an important role in memory. We examined the relationship between structural connectivity of the hippocampus and cortical/subcortical areas and cognitive impairment in schizophrenia, major depressive disorder and bipolar disorder. Subjects comprised 21 healthy controls, 19 patients with schizophrenia, 20 patients with bipolar disorder and 18 patients with major depressive disorder. Diffusion-weighted tensor images data were processed using ProbtrackX2 to calculate the structural connectivity between the hippocampus and cortical/subcortical areas. Cognitive function was assessed using the Brief Assessment of Cognition in schizophrenia composite score. Hippocampal structural connectivity index was significantly correlated with composite score in the schizophrenia group but not in the healthy control, major depressive disorder or bipolar disorder groups. There were no statistically significant differences in hippocampal structural connectivity index between the four groups. Structural connectivity between the hippocampus and cortical/subcortical areas is suggested to be a pathophysiological mechanism of comprehensive cognitive impairment in schizophrenia.  相似文献   
14.
A family of coefficients of relational agreement for numerical scales is proposed. The theory is a generalization to multiple judges of the Zegers and ten Berge theory of association coefficients for two variables and is based on the premise that the choice of a coefficient depends on the scale type of the variables, defined by the class of admissible transformations. Coefficients of relational agreement that denote agreement with respect to empirically meaningful relationships are derived for absolute, ratio, interval, and additive scales. The proposed theory is compared to intraclass correlation, and it is shown that the coefficient of additivity is identical to one measure of intraclass correlation.The author thanks the Editor and anonymous reviewers for helpful suggestions.  相似文献   
15.
16.
17.
Estimating derivatives from noisy displacement data is a notoriously ill-posed problem in signal processing and biomechanics. Following the work of Wood and Jennings (1978) and Hatze (1979, 1981), the present paper describes the use of optimally regularized, natural quintic splines for estimating smoothed positions, velocities, and accelerations from equidistantly sampled, noisy position measurements. It appears that the nature of the boundary conditions of the data is of some importance, since various algorithms used hitherto result in artefacts throughout the data if the true derivatives at the record ends differ significantly from zero. Natural quintic splines do not suffer from this disadvantage below the third derivative.The ill-posed character of movement analysis has some interesting implications for movement synthesis and optimization, similar to the indeterminacy of muscular co-contraction from merely external, biomechanical measurements.  相似文献   
18.
A study was conducted to examine the relation between each of several attitudinal qualities and attitude-behavior consistency. Subjects' attitudes toward volunterring to participate in psychological research were assessed. The number of experiments in which each subject volunteered to participate was employed as the measure of behavior. Attitude-behavior consistency was significantly related to (1) the amount of direct experience upon which the subject's attitude was based (specifically, the number of experiments in which the subject had previously participated), (2) the degree of certainty with which the attitude was held, and (3) how well-defined the subject's attitude was, as measured by the width of his latitude of rejection. These three attitudinal qualities were significantly intercorrelated, suggesting that direct experience with an attitude object may produce an attitude that is both better defined and more confidently held than an attitude formed through more indirect means.  相似文献   
19.
This study investigated the effects of presumably positive and neutral response-contingent stimuli on the occurence of stuttering. Eight adult stutterers spoke spontaneously during a 60-min experimental session, which was divided into three 20-min periods. During Condition I no stimuli were delivered. During Condition II a digital counter and a pair of yellow lights were activated each time the subject stuttered. During Condition III these same response-contingent stimuli were delivered, but with the additional factor that the subject would earn 5¢ each time the counter moved forward and the lights were illuminated. Conditions II and III were counterbalanced across subjects. The experimenter was unaware of which of the two contingencies were operative during Conditions II and III. Results showed no significant changes in occurence of stuttering due to either response-contingent stimulus. A discussion of theoretical and experimental implications is given.  相似文献   
20.
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