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   700篇
  免费   3篇
教育   563篇
科学研究   34篇
各国文化   17篇
体育   7篇
综合类   1篇
信息传播   81篇
  2022年   5篇
  2021年   8篇
  2020年   11篇
  2019年   18篇
  2018年   9篇
  2017年   20篇
  2016年   14篇
  2015年   13篇
  2014年   19篇
  2013年   132篇
  2012年   21篇
  2011年   15篇
  2010年   24篇
  2009年   16篇
  2008年   17篇
  2007年   14篇
  2006年   6篇
  2005年   17篇
  2004年   15篇
  2003年   10篇
  2002年   13篇
  2001年   7篇
  2000年   7篇
  1999年   13篇
  1998年   8篇
  1997年   6篇
  1996年   9篇
  1995年   10篇
  1994年   7篇
  1993年   11篇
  1992年   9篇
  1991年   9篇
  1990年   13篇
  1989年   8篇
  1988年   5篇
  1987年   7篇
  1984年   10篇
  1983年   12篇
  1982年   9篇
  1981年   10篇
  1980年   11篇
  1979年   17篇
  1978年   10篇
  1977年   5篇
  1976年   9篇
  1975年   11篇
  1974年   6篇
  1972年   5篇
  1968年   4篇
  1866年   3篇
排序方式: 共有703条查询结果,搜索用时 15 毫秒
81.
The purpose of this study was to develop and validate instruments that will assess the laboratory skills of students completing high school science courses. In each of the science areas (biology, chemistry, and physics), tests were developed around six laboratory tasks. Each test used a two-part format with a total time of 80 minutes. Students had to plan an investigation, collect and organize appropriate data, and formulate conclusions based on calculations and graphs. A different test was developed for 12th-grade students not enrolled in a science course. This test consisted of a series of stations where students conducted a short activity that was presented to them. Over 1000 students from 32 Ohio schools formed the sample for this study. Data are presented by skill and by task. In addition, analysis for gender and school effects is included.  相似文献   
82.
Maternal behavior and attachment in low-birth-weight twins and singletons   总被引:1,自引:0,他引:1  
Early mother-infant interaction and later security of attachment were assessed for 17 pairs of twins, 5 singleton survivors of twin pairs, and 20 singletons, all low-birth-weight preterm infants. Mother and infant behavior during home observations at 6 weeks and 3, 6, and 9 months was rated on scales developed by Ainsworth and Egeland and Brunquell. A, B, and C patterns of behavior in the Strange Situation conformed to the frequencies predicted from prior full-term samples and were not affected by twinship. However, the proportion of B1 and B4 dyads in the B group significantly exceeded that predicted from normative data. Mothers in B2 and B3 dyads were rated more sensitive and responsive than all others at all 4 observations. Contrary to our expectations that mothers in A and C dyads would receive the lowest ratings, this occurred only at 6 weeks. At later observations mothers in B1 and B4 dyads consistently received the lowest ratings. The discussion focuses on possible reasons for this unexpected finding.  相似文献   
83.
Rats lived continuously in an operant chamber in which they were able to press a bar to obtain food on a chained FR50:CRF schedule that allowed them control of both the size and frequency of individual meals. Independent groups of animals were scheduled to receive 12, 24, 48, or 96 electric shocks per day, which were given randomly in time and independent of the subjects’ behavior. Rats could avoid shock by remaining in a safe area of the chamber, but they were always at risk while barpressing. The introduction of shock resulted in a number of changes in feeding patterns. In rats exposed to a possible 12 shocks/day, meal size increased whereas meal frequency changed very little. At 24 shocks/day, meal frequency decreased whereas meal size increased such that net intake remained stable relative to a preshock baseline period. As shock density was increased to 48 or 96 shocks/day, total intake was suppressed. At 96 shocks/day, both meal frequency and meal size decreased dramatically. Shock-related changes were also observed in rates of operant responding and in the amount of time the animals engaged in feeding-related behavior. All of the animals were able to achieve a greater than 50% reduction in the total number of shocks received relative to equivalent random samples of their position in the apparatus taken during baseline. These results support the position that the nature of defensive changes in feeding behavior that are seen when an aversive stimulus is introduced: into a simulated foraging situation varies as a function of risk.  相似文献   
84.
85.
86.
The study consisted of 25 full-time Electronic Technician Certificate students with 16 randomly assigned to an experimental group registered in a team-taught learning community and with nine randomly assigned to a control group registered for individually taught unlinked classes. We hypothesized that the experimental group would have significantly better academic and social integration and more positive perceptions of their experiences than the control class as well as higher course grades and grade point averages, more contact with classmates and instructors, and greater commitment to college and second semester persistence. Both student self-reported surveys and institutional data were analyzed. Results indicated that the team-taught learning community did make a difference to its students and yielded quantitative and qualitative support for hypotheses dealing with student perceptions of academic and social integration. Findings failed to support hypotheses dealing with behavioral outcomes except for strong support for commitment to college.  相似文献   
87.
Three substudies of effects of different formats on student ratings of faculty teaching effectiveness were conducted. One substudy, Kinds of Keys, investigated three main kinds of keys: Agreement, Evaluation, and Needs Improvement. The second, NO TUP, investigated numbers of positive rating categories. The third, Item Wording Direction, investigated the same items worded positively, negatively, and neutrally, respectively. Practically important differences in level of ratings obtained in Kinds of Keys and practically and statistically significant differences obtained in NO TUP and Item Wording Direction. It was concluded that additional research is necessary to determine if apparent differences in teaching effectiveness are actually differences in teaching effectiveness or differences due to the methods of measurement.  相似文献   
88.
89.
90.
The differential effects of four task selectionmethods on training efficiency and transfer incomputer-based training for Air Traffic Controlwere investigated. A non-dynamic condition, inwhich the learning tasks were presented to theparticipants in a fixed, predeterminedsequence, was compared to three dynamicconditions, in which learning tasks wereselected on the basis of performance, mentaleffort, and a combination of both (i.e., mentalefficiency). Using the 3-factor mentalefficiency formula of Tuovinen and Paas (2004, this issue), the hypothesis that dynamic taskselection leads to more efficient training thannon-dynamic task selection was confirmed.However, the hypothesis that dynamic taskselection based on mental efficiency leads tomore efficient training than dynamic taskselection based on performance or mental effortalone was not supported. The results arediscussed in light of the theoretical frameworkand suggestions are given for futureresearch.  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