职前化学教师TPACK的现状与发展研究

采用自编的职前化学教师TPACK问卷,以902名职前化学教师为调查对象,研究了他们TPACK的发展。结果表明:(1)职前化学教师TPACK存在显著的性别差异,男生的TK、PCK、TPK、TCK、TPCK均值较女生高,而女生的CK、PK均值较高;(2)生源地为城镇的职前化学教师与生源地为农村的职前化学教师在TK、CK 2个维度上存在显著性差异,且农村职前化学教师在CK、PK、PCK、TCK、TPK、TPCK 6个维度的得分均高于城镇职前化学教师;(3)职前化学教师TPACK存在显著的年级差异,随着年级的升高,职前化学教师TPACK呈波浪式持续发展的趋势。     

职前化学教师学科知识与PCK关系的个案研究*——以“物质的量”主题为例

基于“物质的量”主题,探究职前化学教师的学科知识(CK)与学科教学知识(PCK)的关系。数据源包括参与者的CK访谈、内容表征(CoRe)访谈、教学录像、教学设计、反思日志等多元质化数据。采用自下而上的分析归纳法和以Gess-Newsome(2015)PCK模型为框架的演绎法分析数据。研究发现:教师透镜影响学科知识的理解和发展;学科知识影响教学策略和内容表征方式的选择;学科知识不同的职前化学教师均不具备充分的学生理解。     

化学教学设计能力评价量表的编制与应用研究

基于学科教学知识（PCK）编制化学教学设计能力评价量表，并对在职高中化学教师的教学设计能力进行评价，分析化学教师在教学设计中存在的问题，为提高在职高中化学教师教学设计能力提供有针对性的建议。研究表明：（1）高中化学教师在课程知识、学生知识及评价知识维度的项目上均处于未掌握等级；（2）高中化学教师在教学目标知识和教学策略知识维度的多个评价项目上处于基本掌握等级。     

化学职前教师PCK的结构与水平研究

本研究基于定量的研究方式测查189名化学职前教师PCK的结构与水平,结果表明（1）化学职前教师的PCK结构主要包括KoC、KoL、KoS、KoA等4个组分,且该结构具有良好的信度与效度;（2）化学职前教师PCK的4个组分之间存在显著相关,且显性的PCK教学方式比隐性的更有利于职前教师对PCK组分间的整合;（3）化学职前教师的PCK水平除KoS组分水平较为理想,其他知识组分水平均处于中等或中下水平;（4）在不同的PCK教学方式（显性或隐性）下,化学职前教师的PCK水平存在显著性差异。     

高中化学教师PCK结构的调查分析

PCK(Pedagogical Content Knowledge)通常被译为学科教学知识,是教师教学中所使用的主要知识,它决定了教学内容和学生的理解方式,是新手型教师与经验型教师的差距所在。本文从教师化学教学的统领性知识和特定课题的学与教的知识2个大的方面对职前教师和职后教师的PCK结构进行调查,将结果进行对比分析,找出职前教师、新手型教师和经验型教师的差距,并提出提高高中化学教师PCK结构水平的相关建议。     

职前理科教师学科教学知识发展策略研究

虽然学科教学知识（PCK）在教师教育和科学教育领域已经得到世界范围内的广泛关注,但在国内,仍然有许多教师教育者和中学理科教师并不知晓学科教学知识。学科教学知识研究尚未对国内中学理科教师的职前培养与职后培训产生实质影响。依据建构的职前理科教师PCK"四要素"结构模型,并在剖析借鉴国内外教师PCK发展经验的基础上,探索提出了包含四要素独立发展、四要素分别拓展、PCK形成、PCK整体拓展4个阶段性目标的"阶段式PCK发展策略"。     

农村初中化学教师PCK现状及其相关因素的调查研究

学科教学知识(PCK)在国际上已被广泛认为是教师教学知识的核心,并日渐成为一个研究热点.参考有关资料编制了"初中化学教师学科教学知识"调查问卷,并以河北省71位农村初中化学教师为研究对象进行了问卷调查,结果显示:目前农村初中化学教师的总体PCK水平偏低,化学素材知识这一部分得分最低,需要关注农村化学教师学科教学知识的发展.而不同年龄、不同教龄以及不同职称化学教师的PCK水平存在显著性差异.     

PCKg理论及其对化学师范生教育教学的启示

基于舒尔曼学科教学知识（Pedagogical Content Knowledge,简称PCK）概念和科克伦的学科教学识知理论（PCKg）,提出在化学师范生教育教学中,应重视化学知识与教育教学知识的整合;引导师范生关注学生的相异构想;培养师范生调控学习环境的能力;重视化学专业师范生PCKg的动态建构。     

论化学职前教师教学设计能力培养策略

高等师范院校承担着职前教师的教育教学能力的培养,其中教学设计能力是一项非常重要的指标。针对目前化学职前教师在进行教学设计时存在的困惑,提出了培养化学职前教师教学设计能力的策略:通过概念图制作,完善化学学科知识结构;通过专题训练,积累理论性知识;通过教学设计训练,使理论性知识有效转化为实践性知识;通过优秀教学设计案例,进一步积累实践性知识;通过网络资源,积累教学设计经验;通过档案袋评价,激励教育教学能力进步。     

职前化学教师教学反思能力及影响因素研究

以已学习教师教育类系列课程的化学教育专业大三师范生为研究对象,分析其教学反思视频与教学反思日志,研究职前化学教师教学反思能力的广度和深度,并结合访谈探讨影响职前化学教师教学反思能力的主要因素。研究发现,职前化学教师的教学反思能力广度在2～8之间,其中反思到4个维度的最多,总体呈正偏态分布,69.1%的职前化学教师的反思不超过4个维度。职前化学教师的教学反思能力水平较低,47.1%处于技术合理性水平,仅8.7%处于批判反思水平。职前化学教师教学反思能力受到其自身教学反思知识、教师指导、反思环境等多重因素的影响。依据以上研究结果,对职前教师、教师教育机构提出了建议。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.