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   1221篇
  免费   33篇
教育   757篇
科学研究   45篇
各国文化   28篇
体育   237篇
文化理论   14篇
信息传播   173篇
  2024年   1篇
  2023年   11篇
  2022年   10篇
  2021年   18篇
  2020年   43篇
  2019年   51篇
  2018年   105篇
  2017年   104篇
  2016年   91篇
  2015年   57篇
  2014年   51篇
  2013年   327篇
  2012年   57篇
  2011年   47篇
  2010年   28篇
  2009年   35篇
  2008年   31篇
  2007年   34篇
  2006年   26篇
  2005年   17篇
  2004年   20篇
  2003年   16篇
  2002年   14篇
  2001年   6篇
  2000年   2篇
  1999年   3篇
  1998年   5篇
  1997年   8篇
  1996年   3篇
  1995年   4篇
  1994年   2篇
  1993年   4篇
  1992年   2篇
  1990年   1篇
  1989年   1篇
  1988年   1篇
  1987年   2篇
  1986年   2篇
  1985年   2篇
  1982年   2篇
  1981年   1篇
  1980年   3篇
  1978年   1篇
  1973年   1篇
  1972年   1篇
  1966年   1篇
  1947年   1篇
  1935年   1篇
排序方式: 共有1254条查询结果,搜索用时 15 毫秒
981.
Recently there have been newly launched ocean color satellites which target the coastlines at unprecedented scales. Science education curricula can benefit from the provision of small low-cost spectroradiometers and curriculum supplemental materials that can be incorporated in a “hands on” teaching approach to explain and demonstrate remote sensing reflectance principles. A lesson in which a progressive set of spectral measurements of familiar and unfamiliar objects and natural waters acquired by students using a small fiberoptic probe and spectroradiometer is presented. This lesson has a dual purpose. The first is to serve as a teaching supplement to high school science curricula while paralleling the National Science Education Standards (NSES) for NASA ocean color products, as well as other satellite ocean products such as GLI and MERIS. The second is to focus on the scientific goals of the graduate-school bound undergraduate student by providing a fundamental understanding of the principles of passive ocean color remote sensing that will perhaps nurture the interest of some students toward research involving utilization of NASA’s Earth science data products. We intend to have these spectroradiometers readily available for use by teachers in the Earth sciences through a publicly available technology library.  相似文献   
982.
Three‐dimensional (3D) food printing is a new technology that can be used to produce personalized and customized food products. However, very little research has been completed on how 3D food printers could be used as educational tools. As such, the objective of this study was to evaluate how teachers (n = 6), dietitians (n = 6), and nutrition students (n = 11) envision the use of 3D food printers when disseminating information about food and nutrition. Focus groups were conducted with teachers, dietitians, and nutrition students. Initially, the participants were introduced to the concept of 3D food printing and then they were asked how they could use a 3D food printer in their teachings. The participants did not feel that a 3D food printer would enhance their teaching and instead felt it could confuse or frighten people. Also, all of the participants were worried about learning how to 3D print foods. The participants did state that people would be interested in watching a 3D food printer. Furthermore, the teachers and nutrition students indicated they thought a demonstration of a 3D food printer would lead to more interest in food and nutrition. Additionally, they thought a 3D food printer could be used to create visually appealing foods. Overall, until 3D food printers are found in residential and commercial kitchens, the participants did not think it would enhance their teachings; however, they did indicate that 3D food printing demonstrations could lead to students being interested in the food and nutrition fields.  相似文献   
983.
984.
This study evaluates the impact of an independent postmidterm question analysis exercise on the ability of students to answer subsequent exam questions on the same topics. It was conducted in three sections (~400 students/section) of introductory biology. Graded midterms were returned electronically, and each student was assigned a subset of questions answered incorrectly by more than 40% of the class to analyze as homework. The majority of questions were at Bloom's application/analysis level; this exercise therefore emphasized learning at these higher levels of cognition. Students in each section answered final exam questions matched by topic to all homework questions, providing a within-class control group for each question. The percentage of students who correctly answered the matched final exam question was significantly higher (p < 0.05) in the Topic Analysis versus Control Analysis group for seven of 19 questions. We identified two factors that influenced activity effectiveness: 1) similarity in topic emphasis of the midterm-final exam question pair and 2) quality of the completed analysis homework. Our data suggest that this easy-to-implement exercise will be useful in large-enrollment classes to help students develop self-regulated learning skills. Additional strategies to help introductory students gain a broader understanding of topic areas are discussed.  相似文献   
985.
ABSTRACT The analysis of calls to a help desk, in this case calls to a computer help desk, can serve as a rich source of information on the real world problems that individuals are having with the implementation of a new technology. Thus, we propose that an analysis of help desk calls, a form of problem‐based inquiry, can serve as a fast and low cost means of both analyzing training needs and evaluating training. We illustrate the use of problem‐based inquiry through a case study of the analysis of help desk calls made after the delivery of a training program that served to introduce a new type of document management system in a professional services firm. Based on the analysis of help desk calls it should be possible to modify future training so as to enhance transfer to the job environment.  相似文献   
986.
The effect of an auditory cue presented during extinction on spontaneous recovery of a conditioned taste aversion was investigated in three experiments. Experiment 1 demonstrated that the presence of the cue during extinction did not influence saccharin consumption during that phase, and that an aversion to saccharin in the absence of the cue was stronger at 18 days than at 1 day after extinction, representing spontaneous recovery rather than a renewal effect. Experiment 2 showed that a cue presented during extinction and testing reduced spontaneous recovery. Experiment 3 replicated that effect and showed that it depended on the cue’s correlation with extinction and not on an unconditioned effect; cues that had been presented during or prior to conditioning did not reduce spontaneous recovery when presented during testing. The cue’s potential to reduce spontaneous recovery through conditioned inhibition or configural cue learning is discussed, as is the possibility that the cue retrieves a saccharin extinction memory in a manner consistent with Bouton’s (1993) account of spontaneous recovery.  相似文献   
987.
In this paper, we propose a common phrase index as an efficient index structure to support phrase queries in a very large text database. Our structure is an extension of previous index structures for phrases and achieves better query efficiency with modest extra storage cost. Further improvement in efficiency can be attained by implementing our index according to our observation of the dynamic nature of common word set. In experimental evaluation, a common phrase index using 255 common words has an improvement of about 11% and 62% in query time for the overall and large queries (queries of long phrases) respectively over an auxiliary nextword index. Moreover, it has only about 19% extra storage cost. Compared with an inverted index, our improvement is about 72% and 87% for the overall and large queries respectively. We also propose to implement a common phrase index with dynamic update feature. Our experiments show that more improvement in time efficiency can be achieved.  相似文献   
988.
Those involved in training know that creating instructional materials can become a tedious, repetitive process. They also know that business conditions often require training interventions to be delivered in ways that are not ideally structured or timed. This article examines the notion that learning objects can be reused and adapted for performance support systems. By doing so, a performance technologist can develop content for just‐in‐case training and reuse it for just‐in‐time performance support.  相似文献   
989.
990.
This study investigated how changes in the material properties of a landing mat could minimise ground reaction forces (GRF) and internal loading on a gymnast during landing. A multi-layer model of a gymnastics competition landing mat and a subject-specific seven-link wobbling mass model of a gymnast were developed to address this aim. Landing mat properties (stiffness and damping) were optimised using a Simplex algorithm to minimise GRF and internal loading. The optimisation of the landing mat parameters was characterised by minimal changes to the mat's stiffness (<0.5%) but increased damping (272%) compared to the competition landing mat. Changes to the landing mat resulted in reduced peak vertical and horizontal GRF and reduced bone bending moments in the shank and thigh compared to a matching simulation. Peak bone bending moments within the thigh and shank were reduced by 6% from 321.5 Nm to 302.5Nm and GRF by 12% from 8626 N to 7552 N when compared to a matching simulation. The reduction in these forces may help to reduce the risk of bone fracture injury associated with a single landing and reduce the risk of a chronic injury such as a stress fracture.  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