全文获取类型
收费全文 | 16116篇 |
免费 | 199篇 |
国内免费 | 119篇 |
专业分类
教育 | 11101篇 |
科学研究 | 2071篇 |
各国文化 | 118篇 |
体育 | 1387篇 |
综合类 | 11篇 |
文化理论 | 125篇 |
信息传播 | 1621篇 |
出版年
2021年 | 111篇 |
2020年 | 222篇 |
2019年 | 331篇 |
2018年 | 449篇 |
2017年 | 412篇 |
2016年 | 407篇 |
2015年 | 256篇 |
2014年 | 336篇 |
2013年 | 2787篇 |
2012年 | 310篇 |
2011年 | 358篇 |
2010年 | 260篇 |
2009年 | 252篇 |
2008年 | 273篇 |
2007年 | 308篇 |
2006年 | 286篇 |
2005年 | 280篇 |
2004年 | 270篇 |
2003年 | 263篇 |
2002年 | 249篇 |
2001年 | 262篇 |
2000年 | 278篇 |
1999年 | 284篇 |
1998年 | 148篇 |
1997年 | 156篇 |
1996年 | 190篇 |
1995年 | 177篇 |
1994年 | 135篇 |
1993年 | 145篇 |
1992年 | 217篇 |
1991年 | 231篇 |
1990年 | 235篇 |
1989年 | 263篇 |
1988年 | 213篇 |
1987年 | 231篇 |
1986年 | 220篇 |
1985年 | 258篇 |
1984年 | 228篇 |
1983年 | 213篇 |
1982年 | 176篇 |
1981年 | 173篇 |
1980年 | 162篇 |
1979年 | 248篇 |
1978年 | 193篇 |
1977年 | 184篇 |
1976年 | 151篇 |
1975年 | 135篇 |
1974年 | 155篇 |
1973年 | 138篇 |
1971年 | 121篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
Polly R. Husmann Valerie Dean O'Loughlin Mark W. Braun 《Anatomical sciences education》2009,2(5):218-226
This study compares overall laboratory averages and individual test scores along with a student survey to determine the effects of using virtual microscopy in place of optical microscopes in a large undergraduate human anatomy course. T‐tests revealed that the first two laboratory examinations (of four) and the overall laboratory averages were significantly increased compared with the previous year. We hypothesize that this is due to students' ability to use and understand the technology quickly as opposed to learning how to maneuver an optical microscope. Students also responded positively in a survey about the virtual microscope, indicating that increased accessibility, ease of use, and the ability to understand the material were important components of the virtual microscope. In addition, an increase in student collaboration was noted because multiple students were able to view the image at a time. This level of acceptance of virtual microscopy has been reported in previous studies, though this level of increased examination scores is rare. We attribute this to differences between the medical students, with whom this technology has been researched in the past, and undergraduate introductory students. Anat Sci Educ 2:218–226, 2009. © 2009 American Association of Anatomists. 相似文献
992.
A near‐peer (NP) teacher discussing structures of the head and neck region with first‐ and second‐year students in the anatomy laboratory at Brighton and Sussex Medical School. NP teachers are fourth‐year medical students who elect to teach in gross anatomy practical classes delivered to first‐ and second‐year medical students. Evans and Cuffe discuss design, implementation and outcomes of the NP teaching program in the current issue of ASE. 相似文献
993.
This study investigated students' with visual impairment concepts about linear size and scale. Specifically the study examined the accuracy of students' concepts over many orders of magnitude as well as experiences students have had in and out‐of‐school learning about size and scale. The results of assessments of 17 students with visual impairment were compared to those of students with normal sight. The study showed that students with visual impairment were most accurate for measurements in the human scale and were least accurate with very large and very small scales that cannot be directly experienced. However, when compared to students with normal sight, students with visual impairment were more accurate at large and small scales than their normally sighted peers. © 2009 Wiley Periodicals, Inc. J Res Sci Teach 46: 506–519, 2009 相似文献
994.
Brian E. Vaughn Nana Shin Mina Kim Gabrielle Coppola Lisa Krzysik António J. Santos Inês Peceguina João R. Daniel Manuela Veríssimo Anthon DeVries Eric Elphick Xiomara Ballentina Kelly K. Bost Wanda Y. Newell Ellaine B. Miller J. Blake Snider Byran Korth 《Child development》2009,80(6):1775-1796
The generality of a multilevel factorial model of social competence (SC) for preschool children was tested in a 5‐group, multinational sample (N = 1,540) using confirmatory factor analysis. The model fits the observed data well, and tests constraining paths for measured variables to their respective first‐order factors across samples also fit well. Equivalence of measurement models was found at sample and sex within‐sample levels but not for age within sample. In 2 groups, teachers’ ratings were examined as correlates of SC indicators. Composites of SC indicators were significantly associated with both positive and negative child attributes from the teachers’ ratings. The findings contribute to understanding of both methodological and substantive issues concerning SC in young children. 相似文献
995.
Erina L. MacGeorge Scott R. Homan John B. Dunning Jr. David Elmore Graham D. Bodie Ed Evans Sangeetha Khichadia Steven M. Lichti Bo Feng Brian Geddes 《Educational technology research and development : ETR & D》2008,56(2):125-145
In the past few years, audience response technology (ART) has been widely adopted on college campuses, and is especially popular
among instructors of large lecture classes. Claims regarding ART’s benefits to students have received only limited empirical
evaluation, and prior studies exhibit methodological limitations. The current study provides a multi-dimensional evaluation,
utilizing a newly-developed measure, the Audience Response Technology Questionnaire (ART-Q). Data were provided at three points during a semester by undergraduate students (n = 854) who used ART in three large lecture university courses. Results indicate moderately positive evaluations of ART on
some dimensions (e.g., ease of use, impact on attendance), with less positive evaluations on others (e.g., influence on preparation
for class). These evaluations showed some variability across time of semester and course, but were not substantially affected
by gender, ethnicity, or year in school. Findings are discussed with respect to the need for future research on instructors’
techniques for using ART and their influence on student perceptions and outcomes.
相似文献
Erina L. MacGeorgeEmail: |
996.
Four pigeons responded on a two-component multiple token-reinforcement schedule, in which tokens were produced according to
a random-interval 30-sec schedule and exchanged according to a variable-ratio 4 schedule in both components. To assess the
effects of contingent token loss, tokens were removed after every second response (i.e., fixed-ratio 2 loss) in one of the
components. Response rates were selectively lower in the loss components relative to baseline (no-loss) conditions, as well
as to the within-condition no-loss components. Response rates were decreased to a greater degree in the presence of tokens
than in their absence. To control for the effects of changes in the density of token and food reinforcement, two parts consisted
of additional conditions where food density and token loss were yoked to those in a previous loss condition. In the yoked-food condition, tokens were produced as usual in both components, but the overall density of food reinforcement in one of the
components was yoked to that obtained during a previous token-loss condition. In the yoked token-loss condition, tokens were removed during one component of the multiple schedule at a rate that approximately matched the obtained
rate of loss from a previous token-loss condition. Response rates in these yoked components were less affected than those
in comparable loss components, despite similar densities of token, exchange, and food reinforcement. On the whole, the results
support the conclusion that contingent token loss serves as an effective punisher with pigeons. 相似文献
997.
Humans prefer (conditioned) rewards that follow greater effort (Aronson & Mills, 1959). This phenomenon can be interpreted
as evidence for cognitive dissonance (or as justification of effort) but may also result from (1) the contrast between the
relatively greater effort and the signal for reinforcement or (2) the delay reduction signaled by the conditioned reinforcer.
In the present study, we examined the effect of prior force and prior time to produce stimuli associated with equal reinforcement.
As expected, pressing with greater force or for a longer time was less preferred than pressing with less force or for a shorter
time. However, participants preferred the conditioned reinforcer that followed greater force and more time. Furthermore, participants
preferred a long duration with no force requirement over a shorter duration with a high force requirement and, consistent
with the contrast account but not with the delay reduction account, they preferred the conditioned stimulus that followed
the less preferred, shorter duration, high-force event. Within-trial contrast provides a more parsimonious account than justification
of effort, and a more complete account than delay reduction. 相似文献
998.
999.
Relational Aggression, Gender, and Social-Psychological Adjustment 总被引:40,自引:2,他引:40
Prior studies of childhood aggression have demonstrated that, as a group, boys are more aggressive than girls. We hypothesized that this finding reflects a lack of research on forms of aggression that are relevant to young females rather than an actual gender difference in levels of overall aggressiveness. In the present study, a form of aggression hypothesized to be typical of girls, relational aggression, was assessed with a peer nomination instrument for a sample of 491 third- through sixth-grade children. Overt aggression (i.e., physical and verbal aggression as assessed in past research) and social-psychological adjustment were also assessed. Results provide evidence for the validity and distinctiveness of relational aggression. Further, they indicated that, as predicted, girls were significantly more relationally aggressive than were boys. Results also indicated that relationally aggressive children may be at risk for serious adjustment difficulties (e.g., they were significantly more rejected and reported significantly higher levels of loneliness, depression, and isolation relative to their nonrelationally aggressive peers). 相似文献
1000.
Research on memory for time has been limited by the difficulty of disentangling several of the fundamentally different processes that contribute to a chronological sense of the past. This study used a developmental approach to isolate one of these processes, impressions of distances in the past. Large samples of children between 3 and 12 years were asked to judge which was longer ago, their birthday or Christmas (and, in one study, Halloween and Thanksgiving). Even children under 6 years of age were able to discriminate the recency of their birthday and Christmas with great accuracy when the events were widely separated and one was within the past several months. The ability to discriminate recency on these scales appears to be a basic property of human memory that changes little with development. Other information about the locations of the events and their relative times of occurrence could only be interpreted correctly by children older than 9 years. 相似文献