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   421篇
  免费   9篇
教育   361篇
科学研究   7篇
各国文化   12篇
体育   12篇
文化理论   3篇
信息传播   35篇
  2022年   4篇
  2021年   4篇
  2020年   11篇
  2019年   11篇
  2018年   16篇
  2017年   21篇
  2016年   14篇
  2015年   15篇
  2014年   9篇
  2013年   83篇
  2012年   17篇
  2011年   2篇
  2010年   6篇
  2009年   8篇
  2008年   7篇
  2007年   6篇
  2006年   7篇
  2005年   3篇
  2004年   14篇
  2003年   5篇
  2002年   8篇
  2001年   8篇
  2000年   2篇
  1999年   5篇
  1998年   2篇
  1997年   4篇
  1996年   4篇
  1995年   4篇
  1994年   5篇
  1993年   9篇
  1992年   6篇
  1991年   3篇
  1990年   7篇
  1989年   6篇
  1988年   3篇
  1987年   2篇
  1986年   6篇
  1985年   6篇
  1984年   11篇
  1983年   6篇
  1982年   7篇
  1981年   3篇
  1980年   4篇
  1979年   9篇
  1978年   7篇
  1977年   6篇
  1976年   5篇
  1975年   6篇
  1974年   4篇
  1970年   3篇
排序方式: 共有430条查询结果,搜索用时 15 毫秒
51.
Sixty females and 60 males between 10 and 15 years of age were interviewed about difficulties in current and past close same-sex friendships. Based on prior studies, it was hypothesized that females' closest same-sex friendships would be more fragile than those of males. Analyses comparing only the closest same-sex friendship of the two sexes demonstrated that females' current friendships were of a shorter duration, that females were more distressed than males when imagining the potential termination of their friendships, that more females' than males' friends already had done something to hurt the friendship, and that females had more former friendships that had ended than males had. Possible reasons are discussed for the greater vulnerability of this type of relationship for females.  相似文献   
52.
Pigeons learned to respond at one spatial position when a pair of stimuli matched and at a different spatial position when they mismatched. All birds were then transferred to novel stimuli on an orthogonal dimension. For the positive-transfer group, the correct positions for matching and mismatching stimuli remained as they were during training. For the negative-transfer group, the correct positions were reversed. In Experiment 1, the birds were trained with shape stimuli and transferred to hue stimuli. Significant group differences were found, in spite of considerable stimulus-specific learning. In Experiment 2, when the same birds (counterbalanced for Experiment 1 transfer group) were transferred to steady-intermittent stimuli, even larger group differences were found. The data indicate that pigeons have some capacity for representing the concepts “same” and “different” with arbitrary stimuli (i.e., symbols). The data further suggest that distinctions that have been made between matching/oddity transfer tasks and same/different tasks may be procedural rather than conceptual.  相似文献   
53.
Understanding what teachers need to be more comfortable and confident in their profession is crucial to the future of effective teachers and scientific literacy in public schools. This study focuses on the experiences of Arizona biology teachers in teaching evolution, using a clinical model of stress to identify sources of pressure, the resulting stresses, and coping strategies they employ to alleviate these stresses. We conducted focus groups, one‐on‐one interviews, and written surveys with 15 biology teachers from the Phoenix area. On the basis of their responses, teachers were clustered into three categories: “Conflicted,” who struggle with their own beliefs and the possible impact of their teaching, “Selective,” who carefully avoid difficult topics and situations, and “Scientists,” who see no place for controversial social issues in their science classroom. Teachers from each group felt that they could be more effective in teaching evolution if they possessed the most up‐to‐date information about evolution and genomics, a safe space in which to reflect on the possible social and personal implications with their peers, and access to richer lesson plans for teaching evolution that include not only science but personal stories regarding how the lessons arose, and what problems and opportunities they created. © 2004 Wiley Periodicals, Inc. J Res Sci Teach 41: 791–809, 2004  相似文献   
54.
In this study of a management writing course delivered via interactive television (ITV) and video streaming (VS), we examine the impact of video-based media on the instructor's pedagogy. Using grounded theory as a methodological lens, we arrive at two core categories, contact and interactivity, and four subcategories, presence, control, dialogue, and liveliness. After a careful analysis of these categories, we claim that video-based delivery deserves attention because it represents a promising component of distance learning writing instruction. Video allows an instructor to reintroduce talking as a means of learning into the arena of distance education, which tends to be dominated by text-heavy, Web-based methods of delivery. In fact, the emergence of liveliness as a category suggests that, for distant students, active learning occurs during spontaneous discussions made possible by video components. Video-based media that complement text-based interactivity can support social constructionist pedagogy in distance learning.  相似文献   
55.
56.
Latency measures of starting to drink and of consummatory behavior were used to investigate ingestional neophobia to novel visual and novel taste cues in chicks. In Experiment 1 (N = 36), latencies to start drinking were reliably shorter to ingesta that appeared familiar from previous rearing or preexposure procedures. After drinking started, consummatory responding occurred reliably more rapidly to familiar taste cues than to novel ones. However, the presence of familiar visual cues reliably facilitated consumption of a novel taste. Experiments 2 and 3 (Ns = 144 and 180) were performed to evaluate, respectively, whether the ingestional effects of taste stimulus intensity, 0%–6% vinegar, and of visual stimulus intensity, 0%–1.0% concentrations of red food-coloring in water, changed during ontogeny for chicks 3, 5, and 7 days old. In Experiment 2, reliable direct effects of taste concentration on consummatory response latencies occurred immediately in 7-day-olds but were delayed in 3-day-olds. In Experiment 3, each age group immediately showed reliably slower starting and consummatory response times, the higher the concentration of red food-coloring. Intake performance in both experiments was consistent with the latency data. Experiments 1–3 showed that visual and taste cues of ingesta separately influenced approach and consummatory behaviors of the ingestive response sequence and that these influences depend on ontogenetic events.  相似文献   
57.
单宁对杨梅汁花色苷稳定性的影响   总被引:16,自引:0,他引:16  
分析了单宁对增加杨梅汁花色苷稳定性的效果。在pH=4.5和pH=3.2时加入单宁使杨梅汁最大吸收波长和最大吸光度增大。在pH为1.0时单宁浓度增大导致杨梅汁最大吸收波长增大,但最大吸光度没有增加。单宁和杨梅汁花色苷的辅助色素反应为放热反应,其△H等于-8.481kJ/mol, △S为7.286J/mol。温度的升高促进辅助色素反应向分解方向进行。  相似文献   
58.
59.
PURPOSE: This study describes the system architecture and user acceptance of a suite of programs that deliver information about newly updated library resources to clinicians' personal digital assistants (PDAs). DESCRIPTION: Participants received headlines delivered to their PDAs alerting them to new books, National Guideline Clearinghouse guidelines, Cochrane Reviews, and National Institutes of Health (NIH) Clinical Alerts, as well as updated content in UpToDate, Harrison's Online, Scientific American Medicine, and Clinical Evidence. Participants could request additional information for any of the headlines, and the information was delivered via e-mail during their next synchronization. Participants completed a survey at the conclusion of the study to gauge their opinions about the service. RESULTS/OUTCOME: Of the 816 headlines delivered to the 16 study participants' PDAs during the project, Scientific American Medicine generated the highest proportion of headline requests at 35%. Most users of the PDA Alerts software reported that they learned about new medical developments sooner than they otherwise would have, and half reported that they learned about developments that they would not have heard about at all. While some users liked the PDA platform for receiving headlines, it seemed that a Web database that allowed tailored searches and alerts could be configured to satisfy both PDA-oriented and e-mail-oriented users.  相似文献   
60.
In team sports, tactical periodisation refers to the planned manipulation of training loads with the aim of prioritising athlete readiness for matches of greatest importance. Although monitoring of athletes’ physical condition is often used to inform this planning, the direct influence of external factors on match difficulty has not been well quantified. In this study, a ‘match difficulty index’ (MDI) for use in Super Rugby was developed, based on the influence imparted by five external factors on previous match outcomes. Specifically, information relating to match location, days break between matches, time-zone change and opposition ladder position (both current and previous year) were collected for matches played during the 2011–2013 Super Rugby seasons. Logistic regression analyses were used to assess the importance of each of these factors with respect to match outcome (win/loss), with opposition ladder position and match location (home, domestic away or international) exerting the greatest influence on match difficulty. Three separate cross-validated models were constructed, with match outcome classification performance reported as 66.2%, 65.5% and 63.7% respectively. The three MDI models emanating from this study can each be used to inform tactical periodisation program design both prior to and during the regular season.  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