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1.
杨承印  龙彦达  杨帆 《化学教育》2016,37(11):43-46
通过弗兰德斯互动分析系统(FIAS),对甘肃省临夏中学专家型教师L的课堂教学进行量化处理,进而分析课堂中师生互动情况,评价、总结出该教师的课堂教学特征:关注学生现场生成性问题,表扬学生优点与引导学生思维时机得当。从而为新手型化学教师通过教学实践来促进个人专业发展提供依据。  相似文献   

2.
以化学课堂及信息技术的互动分析编码系统(CCITIAS)为研究工具,对专家型化学教师的一节实验课堂的教学行为进行分析研究。发现专家型化学教师在课堂中灵活运用多种行为组合,促进师生高效语言互动,凸显课堂“留白”艺术,创设“时空化”实验课堂。  相似文献   

3.
梁永平 《化学教育》2013,34(10):3-7
教师的教学认知支配着教师的教学行为和专业发展。教师教学认知图式的丰富性体现了教师的专业发展水平。教师的教学认知图式具有3个层次:第1层次是要素性教学认知图式,包括对教学内容的认知、学生已有知识或经验的分析、学习目标的设计、作业设计、教学基本思路的形成、学习主题设计、教学活动设计以及教学反思等8个基本要素;第2层次是内容类型教学认知图式;第3层次是具体内容的教学认知图式。  相似文献   

4.
杨蓓  史红霞 《化学教育》2021,42(5):54-65
为探讨不同发展阶段的高中化学教师对于“物质的量”主题的认识,聚焦学科教学知识(PCK)的2个基本组成部分:(1)学生理解的知识,(2)教学策略和表征知识。基于PCK课堂观察量表和CoRe模型,对比分析新手、熟手、专家型教师关于“物质的量”主题的PCK表征。研究结果表明,不同发展阶段化学教师的PCK存在差异,教师对学生知识的理解影响了教学策略和表征方式的决策。  相似文献   

5.
专家型化学教师教学知识发展途径   总被引:1,自引:0,他引:1  
对29位专家型化学教师教学知识来源的调查发现,自身的教学经验和反思、有组织的专业活动是最重要的来源;阅读专业书刊、同事间日常交流、教科书、在职专业培训是比较重要的来源;职前培训是一般来源,而作为中小学学生时的经验是最不重要的来源。  相似文献   

6.
通过对熟手教师和新手教师的6节常态课堂中教学行为对类型、所用时间以及分布特征进行对比分析,发现熟手教师在各个小类教学行为对上的使用、教学行为转换上好于新手教师,新手教师在教学行为对使用的时间利用率上低于熟手教师。在常态课教学中,熟手教师和新手教师都应该多尝试采用开放度较高的教学行为对,新手教师要更加关注学生,引导学生思考,积极参与课堂。  相似文献   

7.
通过观察法记录某专家型教师在不同班级的授课情况,从学生参与情况、教学内容的调整2个层面分析了课间二次备课的效果,认为课间二次备课是专家型教师特有的一种教学机智。  相似文献   

8.
单媛媛  郑长龙 《化学教育》2022,43(23):56-60
在核心素养导向的化学教学实践新时代背景下,基于化学学科理解构建相应主题的认识模型,提升教师的化学学科理解水平,进而开展素养为本的课堂教学促进教师专业发展,为化学教育理论和实践研究提供了重要的思路和方向。以电化学主题为例,基于化学学科理解构建其认识模型,以期其研究思路和过程对化学学科其他主题的理论和教学研究具有启示作用。  相似文献   

9.
宁燕丹  王磊  陈颖  徐敏  陈松  尚荣荣 《化学教育》2018,39(19):15-22
以“探秘神奇的医用胶”为主题设计实施了素养导向的项目教学。从教师行为的角度,对本次项目教学的课堂录像编码分析,发现本次项目教学的3个关键过程、7种高频行为类型、7种高频和次高频问题类型。根据编码结果回顾课堂录像,分析讨论教师在项目教学中如何通过高频行为类型、高频和次高频问题类型帮助学生建立有机物和有机反应的认识角度和认识思路,促进学生化学学科核心素养的发展。  相似文献   

10.
采用课堂观察和"教学行为对"分类理论,对新课程背景下新手与专家教师"化学键"课堂教学行为进行了个案比较研究。研究结果表明新手与专家教师在课堂教学行为方面存在较大差异。在总结新手和专家教师课堂教学行为特征和差异的基础上,对新手教师教学行为的改进提出了建议。  相似文献   

11.
The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.  相似文献   

12.
非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。  相似文献   

13.

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

  相似文献   

14.
Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.  相似文献   

15.
针对恶臭测试的环境影响问题,提出了解决的实例方案,并对方案的要点及优缺点进行讨论,此方案在实际操作中具有较好的效果。  相似文献   

16.
翟宗玺  刘树深  夏树屏 《化学学报》1990,48(10):946-950
用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。  相似文献   

17.
In this review, the research of the author in the field of colloidal systems is summarized. The factors influencing colloidal stability are systematized and analyzed. Examples are presented to illustrate the practical utilization of the theory of stability of colloids and thin films.This review was prepared on the basis of the works of the author, which were awarded the State Premium for 1991 in the field of science and technology, chemistry section.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1708–1717, August, 1992.  相似文献   

18.
Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, Mo, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.  相似文献   

19.
袁丽秋 《化学教育》2006,27(5):8-10
面对日益枯竭的能源危机,氢能是一种洁净、最有前景的替代能源。目前在各种制氢的方法中光催化分解水制氢的研究最多,光解水过程中催化剂最关键,本文对利用太阳能光解水的途径、提高光催化反应效率以及光催化剂的开发研究进行了综述。  相似文献   

20.
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