剖析中美两国青少年田径选材网现状     

吴有凯 《体育科学研究》2012,(1):42-45

以近3届世界田径大赛奖牌榜为线索,对中、美两国青少年田径选材网现状进行剖析。结果显示:天才在当今世界田坛的作用十分重要;我国青少年田径选材网功能缺失,对于天才是等待而不是寻找;美国青少年田径选材网功能强大,对于天才是寻找而不是等待。为提高我国田径水平,必须使青少年田径选材网从等待天才向寻找天才转变。  相似文献   

学习状态研究综述   总被引：1，自引：0，他引：1  

张晶晶 《湖北广播电视大学学报》2010,30(11):15-16

学生的学习状态对学生的学习起了至关重要的作用,引起越来越多的研究者的重视,本研究对学习状态研究现状进行梳理,在此基础上对学习状态的概念及测量工具手段进行整理归纳,并对日后学习状态研究进行了展望,旨在为学习状态理论化和系统化发展提供相关的借鉴。  相似文献   

海森堡模型中的量子纠缠     

李大创  曹卓良 《池州师专学报》2010,(3):36-39

量子纠缠是量子信息处理的重要资源,海森堡模型是一种简单的能够在固态系统中实现的模型,研究海森堡模型中的纠缠将极大地推动固态量子计算机的发展。本文简单介绍了海森堡模型,外磁场和Dzyaloshinskii-Moriya（DM）相互作用参量对系统纠缠的影响,以及现阶段的研究进展。此外,文章还进一步提出了在该领域的研究中需要解决的一些问题。  相似文献   

企业资源型对外直接投资类型选择分析     

吴江  吕契莲 《北京工业职业技术学院学报》2006,5(4):103-107

企业对外进行直接投资时,主要方式包括跨国并购和新设投资,二者的选择是基于投资双方的具体情况而定,具体到自然资源型对外直接投资,根据博弈论的相关分析,我们认为,跨国并购将比新设投资更快、更经济的获得相关目标资产,进而实现企业预期投资目标.  相似文献   

基于最小包含球的领域自适应算法     

刘领全  许敏  刘德强 《温州职业技术学院学报》2013,(4):70-74

相同应用领域因不同时间、地点或设备,检测到的数据域可能会出现不完全一致的现象,从而可能导致机器学习效率降低。为有效地进行数据域间知识传递,在原有支持向量域描述（SVDD）算法的基础上,提出一种全新的数据域中心点校正的领域自适应算法,并使用人造数据集和KDDCUP99大数据集验证算法。实验证明,该领域自适应算法效果较好,将其应用于大数据集可减少核心集元素个数,提高运算效率。  相似文献   

Reconsidering the use of video clubs for student-teachers' learning during field placement: Lessons drawn from a longitudinal multiple case study     

《Teaching and Teacher Education》2018

Although video clubs have been used to support (student) teachers' learning through reflection upon practice, less attention has been paid to their potential use for supporting changes in participants' practice over a period of time. Prior work has also largely treated (student) teachers as an undifferentiated whole that benefits in similar ways from video clubs. In this study, we problematize this assumption by drawing on three cases of student teachers to exemplify three different learning paths while participating in a video club during field placement. Reflecting on these findings, we discuss implications for differentiating the video-club approach to address different student teachers.  相似文献   

Dialogic processes that enable student teachers' learning about pupil learning in mentoring conversations in a Lesson Study field practice     

《Teaching and Teacher Education》2018

This study investigates dialogic processes in student teachers' mentoring conversations in field practice, where Lesson Study (LS) was used as a context for establishing a dialogic learning community in one student group in science. We apply an analytical framework associated with Sociocultural Discourse Analysis to identify utterances that have the potential to create a dialogic space and contribute to ‘interthinking’ among the participants. The findings show the important role of the mentor teacher as a facilitator and a ‘knowledgeable other’, challenging the student teachers to reflect on chosen activities using predictions and detailed observations related to pupils' learning.  相似文献   

基于96单片机控制的现场仪表研究     

周密 《襄樊职业技术学院学报》2008,7(2):8-10

现场总线（Fieldbus）是一种全数字化、双向、多站的通信系统。开放性、分散性与数字通讯是现场总线系统最显著的特征。CAN总线是现场总线中比较容易实现、价格低廉的一种．其性能却不比其他现场总线差,在众多领域被广泛应用。基于96单片机控制的现场仪表就是基于CAN总线的现场仪表。概述了现场总线和CAN总线的发展以及技术特点,并给出具体的软硬件设计。  相似文献   

基于免疫算法和人工势场的移动机器人路径规划     

刘芳 《教育技术导刊》2008,7(4):51-53

分析了人工势场模型存在的两个问题:目标不可到达问题和由于局部最优解的存在而产生的死锁问题。在人工势场路径规划的基础上,提出了基于免疫算法和人工势场法的最优路径规划方法。通过仿真算例验证了该模型的有效性。  相似文献   

Evaluation and application of an efficient plant DNA extraction protocol for laboratory and field testing     

Qi WANG  Xiaoxia SHEN  Tian QIU  Wei WU  Lin LI  Zhi'an WANG  Huixia SHOU 《Journal of Zhejiang University. Science. B》2021,22(2):99

Nucleic acids in plant tissue lysates can be captured quickly by a cellulose filter paper and prepared for amplification after a quick purification.In this study,a published filter paper strip method was modified by sticking the filter paper on a polyvinyl chloride resin(PVC)sheet.This modified method is named EZ-D,for EASY DNA extraction.Compared with the original cetyl trimethylammonium bromide(CTAB)method,DNA extracted by EZ-D is more efficient in polymerase chain reaction(PCR)amplification due to the more stable performance of the EZ-D stick.The EZ-D method is also faster,easier,and cheaper.PCR analyses showed that DNA extracted from several types of plant tissues by EZ-D was appropriate for specific identification of biological samples.A regular PCR reaction can detect the EZ-D-extracted DNA template at concentration as low as 0.1 ng/μL.Evaluation of the EZ-D showed that DNA extracts could be successfully amplified by PCR reaction for DNA fragments up to 3000 bp in length and up to 80%in GC content.EZ-D was successfully used for DNA extraction from a variety of plant species and plant tissues.Moreover,when EZ-D was combined with the loop-mediated isothermal amplification(LAMP)method,DNA identification of biological samples could be achieved without the need for specialized equipment.As an optimized DNA purification method,EZ-D shows great advantages in application and can be used widely in laboratories where equipment is limited and rapid results are required.  相似文献