LBCD课程模式干预下化学职前教师PCK发展实证研究

本研究设计《化学PCK量表式问卷》测查204名化学职前教师在LBCD课程模式干预前后PCK组分水平的变化,并检验问卷的信效度和Magnusson等人提出的PCK五组分模型的合理性。研究结果表明：(1)问卷具有良好的信效度;(2)PCK五组分模型具有一定的合理性;(3)LBCD课程模式对化学职前教师PCK组分发展有统计学意义上的显著促进效果,且各组分的发展呈现出不均衡性。文末据此对化学PCK测评和组分界定,以及化学教师教育提出将LBCD课程模式应用在不同教师群体、参考本研究的方法定量检验其他学者提出的PCK组分模型等建议。     

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“科学探究教学”PCK调查研究*

基于PCK的视角,采用问卷法调查30名职前化学教师对科学探究教学所持的认识,通过质性编码分析其认识组分,并利用量规评价组分的整合水平,结果表明其组分及整合为中低水平,即认识水平较低。据此对我国职前化学教师培养及教师教育研究提出建议。     

职前和在职化学教师“化学平衡”课堂教学解释能力的对比

运用录像分析法,以Hannah Sevian和Lisa Gonsalves设计的教师课堂教学解释能力评价量表为工具,对职前和在职化学教师课堂教学解释能力（以“化学平衡”内容为例）进行测评。研究发现：职前化学教师和在职化学教师的课堂教学解释能力在一般性教学知识（PK）、学科内容知识（CK）、学科教学知识（PCK）等3方面均存在显著差异,即职前化学教师得分由高到低分别为PK、CK、PCK,在职化学教师得分由高到低则分别为PK、PCK、CK;具体差异主要体现在“事实性知识”“将知识运用到不同情境中的能力”“使用心智图像解释”“搭建解释”等方面。     

国内外化学教师PCK的实证研究述评

主要从PCK的测查、发展及其影响因素3个方面梳理国内外化学教师PCK的实证研究。综述表明：（1）这些研究侧重于对PCK多个组分及其关系的整体测查;（2）研究者主要采用外驱型与内驱型2种策略以发展化学教师的PCK;（3）影响化学教师PCK发展的因素主要包括其自身的教育背景、教学经验、反思、实践导师的指导等,同时学科知识与信念对PCK的影响也日益受到重视。基于国内外化学教师PCK研究趋势的对比,文末对我国化学教师PCK的实证研究以及化学师范生教育提供相应的建议。     

国内外理科PCK理论研究的进展与启示

主要从概念框架、定义取向、组分界定、理论模型、学科与主题专属性等5个方面,对国内外理科（化学）PCK理论研究进行较系统地梳理。综述表明：（1）已有研究主要以舒尔曼的PCK概念框架为基础;（2）采用“静态结构观”或“动态建构观”的定义取向;（3）重视PCK组分的界定及其相互关系;（4）使用“整合型”或“转化型”理论模型诠释SMK与PCK的关系;（5）强调PCK的学科与主题专属性。文末基于国内外的研究进展,对我国化学PCK的理论研究提供相应的启示。     

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"。     

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。     

PLC干预下的全日制化学教育硕士PCK发展的个案研究——以“离子反应”教学实践为例

通过工具性个案研究,旨在探查不同阶段的教师专业学习共同体（professional learning community,PLC）干预下职前全日制化学教育硕士的PCK发展,并在此基础上探讨所构建的PLC干预模式的合理性。对1位全日制教育硕士在教育实践过程中的多种数据类型进行收集,采用帕克等人所构建的PCK结构模型进行特征分析和比较,发现全日制教育硕士的PCK结构在经过PLC干预后有显著改善,尤其是各个要素之间的整合更加紧密;不同干预阶段对全日制教育硕士PCK发展作用方式和影响程度不尽相同。PLC干预模式能够促进职前全日制化学教育硕士的PCK发展,然而,其机理及其带来的PCK改变的持久性和稳定性还有待进一步研究。     

职前化学教师教学目标观的调查研究——基于化学核心素养的视角

从化学核心素养的视角测查204名职前化学教师的教学目标观（包括期望观和效能观）。探索性与验证性因子分析结果表明,职前教师的期望观和效能观均能由4因子或5因子结构解释。另外,基于2种因子结构进行配对样本t检验发现,职前教师的期望观水平显著高于其效能观水平。     

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%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.     

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.     

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.     

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.     

Microwave-assisted copper-catalyzed stereoselective ring expansion of three-membered heterocycles with α-diazo-β-dicarbonyl compounds

Microwave-assisted copper-catalyzed ring expansions of three-membered heterocycles with α-diazo-β-dicarbonyl compounds were investigated. Thiiranes generated 3-acyl-5,6-dihydro-1,4-oxathiines in the presence of copper sulfate and trans-3-acyl-5,6-dihydro-1,4-oxathiines as stereospecific products for 1,2-disubstituted cis-thiiranes through an intramolecular S_N2 process. Oxiranes gave rise to 2-acyl-5,6-dihydro-1,4-dioxines under the catalysis of copper hexafluoroacetylacetonate and cis-3-acyl-5,6-dihydro-1,4-dioxines as stereospecific products for 1,2-disubstituted cis-oxiranes via an intimate ion-pair mechanism. The current method provides a direct and simple strategy in efficient preparation of 3-acyl-5,6-dihydro-1,4-oxathiines and 2-acyl-5,6-dihydro-1,4-dioxines, important agents in medicinal and agricultural chemistry, from readily available thiiranes and oxiranes, respectively.     

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.