全文获取类型
收费全文 | 17738篇 |
免费 | 263篇 |
国内免费 | 55篇 |
专业分类
教育 | 13000篇 |
科学研究 | 1226篇 |
各国文化 | 179篇 |
体育 | 1405篇 |
综合类 | 45篇 |
文化理论 | 93篇 |
信息传播 | 2108篇 |
出版年
2022年 | 103篇 |
2021年 | 188篇 |
2020年 | 254篇 |
2019年 | 398篇 |
2018年 | 540篇 |
2017年 | 567篇 |
2016年 | 535篇 |
2015年 | 354篇 |
2014年 | 477篇 |
2013年 | 3631篇 |
2012年 | 470篇 |
2011年 | 494篇 |
2010年 | 433篇 |
2009年 | 411篇 |
2008年 | 443篇 |
2007年 | 426篇 |
2006年 | 426篇 |
2005年 | 371篇 |
2004年 | 264篇 |
2003年 | 258篇 |
2002年 | 245篇 |
2001年 | 379篇 |
2000年 | 309篇 |
1999年 | 261篇 |
1998年 | 164篇 |
1997年 | 159篇 |
1996年 | 175篇 |
1995年 | 147篇 |
1994年 | 161篇 |
1993年 | 147篇 |
1992年 | 221篇 |
1991年 | 217篇 |
1990年 | 240篇 |
1989年 | 220篇 |
1988年 | 180篇 |
1987年 | 187篇 |
1986年 | 198篇 |
1985年 | 183篇 |
1984年 | 186篇 |
1983年 | 182篇 |
1982年 | 148篇 |
1981年 | 149篇 |
1980年 | 136篇 |
1979年 | 194篇 |
1978年 | 167篇 |
1977年 | 119篇 |
1976年 | 122篇 |
1975年 | 119篇 |
1973年 | 110篇 |
1971年 | 119篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
The aim of this study was to examine the relationship between indicators of risk of disordered eating, body image and varied menstrual cycle lengths. Altogether, 151 female athletes were invited from 16 sports and 70 female non-athletic controls were recruited from a university lecture class. The participants completed several surveys, including demographics, menstrual cycle history, physical activity, Eating Disorder Inventory (EDI) and the Three Factor Eating Questionnaire (TFEQ). Selected EDI subscales were summed to reflect eating disorder risk and body image. Menstrual cyclicity was based on self-reported cycle length for the last 6 months (normal cycles = 26-32 days, irregular cycles < or =26 or >32 days). Athletes overall had more irregular cycles (29.1%) than the non-athletes (15.7%) (P < 0.05). There were significant differences in scores for eating disorder risk, body dissatisfaction, drive for thinness, cognitive restraint (TFEQ) and disinhibition (TFEQ), only when athletes were divided based on menstrual cyclicity (i.e. irregularly cycling athletes had higher scores than athletes with normal menstrual cycle lengths). No differences in these scores were found between non-athletes with normal or irregular menstrual cycle lengths. In conclusion, irregularly short or long menstrual cycle length is associated with subtle indications of higher risk of disordered eating in female athletes. 相似文献
102.
Myers ND Wolfe EW Maier KS Feltz DL Reckase MD 《Research quarterly for exercise and sport》2006,77(4):451-463
This study extended validity evidence for multidimensional measures of coaching competency derived from the Coaching Competency Scale (CCS; Myers, Feltz, Maier, Wolfe, & Reckase, 2006) by examining use of the original rating scale structure and testing how measures related to satisfaction with the head coach within teams and between teams. Motivation, game strategy, technique, and character building comprised the dimensions of coaching competency. Data were collected from athletes (N = 585) nested within intercollegiate men's (g = 8) and women's (g = 13) soccer and women's ice hockey (g = 11) teams (G = 32). Validity concerns were observed for the original rating scale structure and the predicted positive relationship between motivation competency and satisfaction with the coach between teams. Validity evidence was offered for a condensed post hoc rating scale and the predicted relationship between motivation competency and satisfaction with the coach within teams. 相似文献
103.
In this paper the problem of memoryless discrete time detection of a constant signal in additive φ-mixing noise is considered. The fidelity criterion is taken to be the asymptotic relative efficiency. The optimal detector nonlinearity is approximated by a polynomial, and the statistical knowledge required for the design of the detector is the family of joint moments of the noise, resulting in a very simple design procedure for the detector. It is shown that the performance of this detector can be made arbitrarily close to that of the optimal memoryless detector for a large class of noises. 相似文献
104.
105.
J. Bruce Francis Michalina Vaughan Colin Flood Page Sally Tomlinson R. A. Becher Margaret C. Ives John Urry K. G. Collier Meir Zadok Charles Carter Jürgen Schramm Jean Barry Graeme C. Moodie Donald Bligh R. A. King D. G. Mulcahy Peter Scott F. R. Charmer T. R. Bone John A. Hughes Roger Greenhough Alec M. Ross John Wakeford Joyce Skinner Duncan B. Nimmo Cedric Cullingford L. R. B. Elton 《Higher Education》1979,8(6):709-744
106.
107.
A bond graph model is derived for the geometric constraints of a three-axis flight table. Gimbal dynamics are easily added even in asymmetrical and unbalanced cases. A method is introduced to make the local dependent inertias computable. The bond graph compares favourably to the Lagrangian approach as to modelling effort and accessibility of intermediate variables as well as having computational advantages. 相似文献
108.
The chief purpose of this study was to identify characteristics that distinguish approach as an attachment behavior from approach serving other behavioral systems. Locomotor approaches of 16 male and 10 female white middle-class infants to an attachment figure (the mother) and to a nonattachment figure (the visitor-observer) were examined under naturalistic conditions at home. Observations were made during 4-hour home visits at 3-week intervals; those from 26 to 54 weeks were used. When approach was examined in a free-choice situation and without regard to behavioral context, infants approached the mother proportionally (though slightly) more often than the visitor (p less than .05). In 2 behavioral contexts, however, spontaneous infant approaches were sharply differential to the mother; approaches accompanied by crying and approaches terminating in a pickup appeal were directed almost exclusively to the mother (p less than .0001 for both). Touching upon completion of the approach was not differential, except in the context of a pickup appeal. Object-oriented approaches were more often directed to the visitor than to the mother (p less than .002) and may be either exploratory or affiliative. It is suggested that neither approach nor touching can be assumed to serve the attachment system without consideration of context- both environmental and behavioral. 相似文献
109.
48 healthy neonates born to multiparae were randomly assigned to view a moving stimulus either in the horizontal or the upright position, with or without added vestibular stimulation and with or without pacifier sucking. The infant was shown a moving black line inside a strictly controlled visual environment provided by an apparatus which permitted horizontal and upright positioning and displacement of the infant. Visual tracking was recorded by a concealed TV camera positioned at a constant distance and angle from the infants' eyes in both positions. Quality of tracking during each of 4 trials was scored on a 7-point scale. Results indicate that vestibularproprioceptive stimulation provided to the infant either horizontally or semivertically significantly enhanced his visual tracking, whereas the upright position did not. Pacifier sucking also improved his performace. 相似文献
110.