初中物理教科书中的能量概念比较研究     

TAN Xiao PEN Zheng 《课程.教材.教法》2008,(12)

当前,在世界范围内,能量概念在科学教育尤其是物理教育中占据着越来越重要的地位。然而,能量概念的特殊性决定了能量概念教学的多样性和复杂性。关于能量概念的教学,我国的中学物理课程与国外的许多教程有较大差异。比较国内外物理教科书中关于能量概念的呈现方式和教学方式的差异,对改进能量概念在教科书中的呈现方式进而帮助学生进一步理解能量的概念具有一定意义。  相似文献   

农业比重下降对国民经济可持续发展的影响   总被引：1，自引：0，他引：1  

刘铮  李先 《辽宁师范大学学报(社会科学版)》2008,31(4):30-33

近年农业在国民经济中所占份额呈逐渐下降趋势。这种下降既有产业演进合理性,又存隐忧。农业基础地位要求政府加大反哺力度,加快土地流转制度改革,鼓励农业创新,拓展经济功能和非经济功能对国民经济增长的推动作用。现阶段,巩固农业的基础地位,应运用“五个统筹”的科学发展观,促进农业与第二、第三产业又好又快协调发展。  相似文献   

关于四种弱BCI-代数及其可分配性     

平征  张海珍  周志峰 《宁德师专学报(自然科学版)》2008,20(1):3-6

引入比BCI-代数条件更弱的四种弱BCI-代数,讨论它们的等价条件,并给出弱BCI-代数的一种二元运算“＋”：x＊y=x＋（x＊y）,讨论了与这种运算相关的可分配性,进而四种弱BCI-代数在可分配下得到统一．  相似文献   

儿童依恋类型的影响因素分析及安全型依恋的培养   总被引：3，自引：0，他引：3  

王金良郑海燕  牟宏伟 《四川教育学院学报》2005,21(8):7-8

本文对影响依恋形成的几个因素进行了分析，这些因素来自父母、家庭以及儿童自身三方面，并且针对这些影响因素我们提出了相应的应对策略，对于培养安全型依恋的儿童具有重要参考价值。  相似文献   

Effects on cytotoxicity and antibacterial properties of the incorporations of silver nanoparticles into the surface coating of dental alloys     

Xiao-ting Shen  Yan-zhen Zhang  Fang Xiao  Jing Zhu  Xiao-dong Zheng 《Journal of Zhejiang University. Science. B》2017,18(7):615-625

The aim of this study was to research the changes in cytotoxicity and antibacterial properties after silver nanoparticles (AgNPs) were incorporated into the surface coating of dental alloys. AgNPs were attached to cobalt chromium alloys and pure titanium using a hydrothermal method, according to the reaction: AgNO₃+NaBH₄→ Ag+1/2H₂+1/2B₂H₆+NaNO₃. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was used to evaluate the cytotoxicity of the alloys when in contact with osteogenic precursor cells (MC3T3-E1) from mice and mesenchymal stem cells (BMSC) from rats. The antibacterial properties of dental alloys incorporating three different concentrations (10, 4, and 2 μmol/L) of AgNPs were tested on Staphylococcus aureus (SA) and Streptococcus mutans (MS). High cytotoxicity values were observed for all dental alloys that contained 0% of AgNPs (the control groups). The incorporation of AgNPs reduced cytotoxicity values. No significant difference was observed for antibacterial performance when comparing dental alloys containing AgNPs to the respective control groups. The results demonstrated that the cobalt chromium alloys and pure titanium all had cytotoxicity to MC3T3-E1 and BMSC and that the incorporation of AgNPs could reduce this cytotoxicity. The concentrations of AgNPs adopted in this study were found to have no antibacterial action against SA or MS.  相似文献   

The effectiveness of self-regulated learning scaffolds on academic performance in computer-based learning environments: a meta-analysis     

Lanqin Zheng 《Asia Pacific Education Review》2016,17(2):187-202

This meta-analysis examined research on the effects of self-regulated learning scaffolds on academic performance in computer-based learning environments from 2004 to 2015. A total of 29 articles met inclusion criteria and were included in the final analysis with a total sample size of 2648 students. Moderator analyses were performed using a random effects model that focused on the three main areas of scaffold characteristics (including the mechanism, functions, delivery forms, mode, and number of scaffolds; how to promote self-regulated learning by scaffolds); demographics of the selected studies (including sample groups, sample size, learning domain, research settings, and types of computer-based learning environments); and research methodological features (including research methods, types of research design, types of organization for treatment, and duration of treatment). Findings revealed that self-regulated learning scaffolds in computer-based learning environments generally produced a significantly positive effect on academic performance (ES = 0.438). It is also suggested that both domain-general and domain-specific scaffolds can support the entire process of self-regulated learning since they demonstrated substantial effects on academic performance. Different impacts of various studies and their methodological features are presented and discussed.  相似文献   

普通高校健美操运动员赛后心理调适方法研究     

王嵘  陈亮  王峥 《嘉应学院学报》2008,26(3)

随着我国各高校竞技健美操训练水平的提高,运动员在比赛中所感受到的赛场心理压力体验势必更加深刻和久远。比赛结果的好坏往往都会对运动员造成一定的心理影响,如果不及时采取措施进行干预,这将会影响运动员赛后正常的训练和比赛。本文尝试分析竞技健美操运动员在赛后可能会出现的心理体验表现,探讨了在赛后的训练中可以采用的几种较实用的心理调适手段。  相似文献   

基于profiling系统的软硬件划分方法研究     

吕争  湛宁 《荆门职业技术学院学报》2008,23(3):56-61

通过对path profiling和loop profiling对软硬件划分作用的分析,发现了在特定条件下pathprofiling相对于loop profiling的优点,并提出了一个新的基于profiling系统的软硬件划分的方法。  相似文献   

美、中教师评价指标体系比较研究     

孙河川  郑丹  葛辉 《教育发展研究》2008,(20)

本文就美中两国最新教师评价体系的一、二级指标进行比较,对两国的相通之处和各自关注的重点予以探讨,并进一步分析美国教师评价指标体系的特点,以期对我国教师评价指标体系的科学构建和完善有所借鉴.  相似文献   

学校对研究性学习的回应行为分析   总被引：2，自引：0，他引：2  

柯政 《教育发展研究》2008,(24)

本文通过调查发现,学校执行研究性学习课程政策时表现出共同的行为方式,即:在课时上,不能按相关要求开足课程;在实施方式上,利用节假日"集中"进行;在教学过程中,重形式轻实质.学校的这种现实回应使研究性学习课程政策在实践中面临被消解的境地.对此,我们不能简单地将其归咎于学校执行政策不力,而应从整个课程政策的制订、执行和调整系统的角度来考量.  相似文献