三种农药诱发柚茎尖细胞微核的比较研究   总被引：1，自引：0，他引：1  

唐正义  胡蓉  黄作喜 《四川职业技术学院学报》2005,15(4):100-102

应用微核技术研究了甲胺磷、甲基硫菌灵、病易克在正常使用浓度范围内对柚茎尖细胞的遗传毒性.结果表明,3种农药对柚茎尖细胞均有一定程度的诱变活性,农药浓度与微核率呈剂量-效应关系.  相似文献   

Cognitive regulations in ICT-supported flipped classroom interactions: An activity theory perspective     

Xiao-Li Zheng  Hoi-Soo Kim  Wen-Hua Lai  Gwo-Jen Hwang 《British journal of educational technology : journal of the Council for Educational Technology》2020,51(1):103-130

In recent years, most studies on flipped classrooms or flipped learning have focused on learners’ motivation, academic achievement and teachers’ and students’ perceptions of the flipped classroom. Little research has involved interactions in the flipped classroom. This study aims to show that in-class collaborative learning in the flipped classroom can not only be conceived as a collective activity consisting of discrete actions, but also as a systematic activity. From the activity-theoretical perspective, contradictions were found between components of an activity such as subject, tools, rules, community, division of labor, object and outcome. This study conducted a pre-experiment, selecting one lesson of the seventh-grade Information Technology Course as the learning content, conducted in a flipped classroom. Three triads with different compositions were specifically observed by recording their interactions. More second-level contradictions existed between subject and tools, and division of labor within the low-level triad than within the other two triads, and more first-level contradictions also occurred within the low-level triad than within the other two triads. Most second-level contradictions within the high-level triad were resolved by self-regulation of cognition. Instead, most second-level contradictions within the mixed-level triad were overcome by co-regulation or shared regulation of cognition. This study sheds light on how to effectively design and implement flipped learning, and provides a new approach for analyzing interactions in the classroom.  相似文献   

小学活动教学初探     

胡重光 《湖南第一师范学报》2001,(Z1)

我国传统课堂教学的根本弊病是学习的被动性和孤立性。活动教学的基本思想是使每个学生都投入主动的学习活动，在活动中实现学生素质的全面发展。据此，应将课堂教学过程变成学生活动的过程，并实行小组合作学习，这就从根本上克服了上述弊病。活动教学的主要理论基础──皮亚杰的发生认识论与马克思主义的认识论是一致的，活动是儿童认识客观对象和发展自我的根本途径。教师应尽可能把课堂教学的时间让给学生，尽可能让学生自己去做，尽可能实行小组合作学习，尽可能面向每一个学生。  相似文献   

On activities and affordances for mobile learning     

《Contemporary educational psychology》2020

Across the articles in this special issue, there is a clear and important focus on how people learn through mobility, which allows them to move across contexts as they learn. This commentary considers ways mobile technologies can support learning with a focus on understanding the affordances to of the mobile technologies develop new learning practices that could not be accomplished without this technology. With this in mind, we return to the definition of mobile learning that suggests mobile learning is learning across multiple contexts, through social interaction, using personal electronic devices that can immediately capture information about, or provide information to the user. To explore how to implement this definition in truly powerful ways, we suggest explicitly unpacking this into its four component parts, so that we can explore and discuss the unique affordances of mobile learning: (1) multiple contexts, (2) social interactions, (3) content interactions, and (4), capturing information and providing information to users in real-time. We further suggest a 5th element, which is the synergies among these different dimensions. We conclude with the challenges in doing research in mobile learning environments and the need to understand both how and what people learn in such environments.  相似文献   

电信运营企业的价值管理理念创新     

姜向荣 《科学与管理》2010,30(1)

本文首先回顾了现代企业管理理论的发展轨迹,进而引入"一体化管理"的五层模型。该模型阐释了企业如何以价值创造为核心展开企业的运作,是价值管理的概念模型。在此概念模型的基础上,立足于时代背景,结合电信运营企业现有的信息化发展现状,进一步整合分散在各个业务子系统的管理系统,打造电信运营企业的价值管理控制系统,使价值管理理念得以落地实施。  相似文献   

目标导向的学习环境设计原理     

贺平 《现代教育技术》2009,19(1):38-42

目标导向的学习环境(Goal-orientated Learning Environments,简称GOLEs)设计原理认为:学习环境与学习过程共生共存,学习目标贯穿整个学习活动过程,持续指导学习环境的设计;学习者通过一定的技术中介与学习环境建立互动关系;学习环境设计围绕学习活动全面展开。笔者据此建立了学习目标导向的学习环境工作图、学习者与学习环境的互动模型和目标导向的学习环境设计流程图,并详细阐述了GOLEs设计原理及其各个要素。  相似文献   

网络学习环境中的科学课程分析活动设计   总被引：1，自引：0，他引：1  

黄淑珍 《现代教育技术》2009,19(6):32-34

科学课程的探究学习活动中,分析是学习过程中的基本步骤,指导是有效分析的前提。文章在认知理论的基础上,明确了网络学习环境中的科学课程分析活动及其指导的特点,设计了科学课程分析活动的过程和步骤,结合科学课程分析活动的网络课件案例予以说明。  相似文献   

两种补养类彝药的红外光谱研究     

杨永安  刘培波  杨发成 《楚雄师范学院学报》2009,24(6):35-39

彝药双参和五气朝阳草都是典型的彝药药材,同属补养药.本文采用傅立叶变换红外光谱法测定彝药双参和五气朝阳草的红外光谱图.分析比较了两种样品在红外光谱图上的异同.结果表明,尽管它们同属补养药,但是它们各自的红外光谱的吸收峰的峰形、吸收位置和强度均有差异.通过对双参和五气朝阳草红外光谱图部分特征峰的药物活性分析,得出两者共同药物活性的分子解释.为双参和五气朝阳草的鉴定和药理分析提供科学的依据.  相似文献   

Authentic science experiences as a vehicle to change students’ orientations toward science and scientific career choices: Learning from the path followed by Brad     

Michiel van Eijck  Wolff-Michael Roth 《Cultural Studies of Science Education》2009,4(3):611-638

Bringing a greater number of students into science is one of, if not the most fundamental goals of science education for all, especially for heretofore-neglected groups of society such as women and Aboriginal students. Providing students with opportunities to experience how science really is enacted—i.e., authentic science—has been advocated as an important means to allow students to know and learn about science. The purpose of this paper is to problematize how “authentic” science experiences may mediate students’ orientations towards science and scientific career choices. Based on a larger ethnographic study, we present the case of an Aboriginal student who engaged in a scientific internship program. We draw on cultural–historical activity theory to understand the intersection between science as practice and the mundane practices in which students participate as part of their daily lives. Following Brad, we articulate our understanding of the ways in which he hybridized the various mundane and scientific practices that intersected in and through his participation and by which he realized his cultural identity as an Aboriginal. Mediated by this hybridization, we observe changes in his orientation towards science and his career choices. We use this case study to revisit methodological implications for understanding the role of “authentic science experiences” in science education.

Michiel van EijckEmail:

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Using activity theory to understand prospective teachers' attitudes to and construction of special educational needs and/or disabilities     

Sue Pearson 《Teaching and Teacher Education》2009

Appropriate professional development, including that initial teacher training, is regarded as a cornerstone of the development of inclusive education. This research is concerned with prospective teachers' conceptualisations of terms such as ‘disability’ and ‘special education’. Activity theory is proposed as a lens through which to consider the complexities involved. In the context of the English systems, this research, using data collected through word association and analysed using activity theory, explored the trainees' conceptualisations. The findings highlight both heterogeneity and homogeneity within a cohort of students, changes over time and implications for those involved in teacher education.  相似文献