化学专业师范生实践性知识水平及影响因素调查研究*

基于自主建构的化学师范生实践性知识水平研究模型,采用自编调查问卷,对河北某高校化学专业271名师范生进行问卷调查,运用SPSS 13.0数据统计分析软件进行数据处理,研究结论如下:(1)化学专业师范生在经过系统的理论学习之后,在实习之前,其实践性知识整体和各维度均处于本研究的中等水平;(2)化学专业师范生实践性知识的5个维度之间具有较强的相关性,各维度在一定程度上相互影响、相互制约;(3)教学经验的积累、大学之前的学习经历、自己敬重和喜欢的老师、优质课的观摩、教学案例分析、微格教学技能训练是影响化学专业师范生实践性知识的主要因素。     

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。     

简析化学实验失败的原因

化学教学中,无论是教师演示实验还是学生分组实验常有不成功的现象出现,并时有事故发生。究其原因,除了化学仪器不够精密、试剂纯度及副反应等客观因素外,绝大多数情况是由于操作者平时对化学实验基本操作和基本技能训练不够重视或者考虑问题不够周到等主观因素所造成的。归纳起来,主要有以下10个方面。     

化学师范生对化学本质及其教学的认识研究

使用问卷调查法与访谈法,以广东某高校的化学师范生为样本,测查了30名化学师范生对化学本质的认识状况、教学意愿及教学策略。结果表明,（1）师范生对化学本质（包括化学知识的性质、来源、论证、评价等维度）的认识主要体现了辩证唯物主义取向;（2）师范生仅在对个别化学本质维度的认识上涉及到化学的学科专属性;（3）师范生有进行化学本质教学的意愿并能阐述原因,但缺乏进行化学本质教学的策略。据此对我国化学师范生教育及其研究提出相关建议。     

化学师范生对模型与模型教学认识的调查研究

使用开放性问卷与访谈法，以广东省某师范院校化学师范生为样本，测查了59名化学师范生对模型及其教学认识。结果表明化学师范生对模型性质（尤其是模型暂定性、条件性以及局限性）与模型教学目标（主要表现在模型方法与模型本质）的认识仍有待加强。文末据此对我国化学师范生培养及其研究提出相关建议。     

地方高校化学师范生对教师职业认同现状及影响因素调查研究

采用问卷和访谈的方式对化学师范生对教师职业认同情况进行了调查。结果表明：化学师范生对教师职业认同总体水平较高;教师职业认同水平在性别上差异不显著;教师职业认同水平在年级上差异显著,大一师范生的认同水平较高。根据调查结果,分析了化学师范生对教师职业认同的影响因素,并就提升化学师范生对教师职业认同提出了建议。     

化学师范生手持技术接受度与TPACK的相关性研究

以技术接受度模型(Technology Acceptance Model, TAM)与TPACK(Technological Pedagogical Content Knowledge,整合信息技术、教学法、学科内容的知识结构)理论为基础,以手持技术为技术接受度模型与TPACK中的技术对象,利用结构方程模型调查研究H大学化学师范生的手持技术接受度与TPACK的相关性。研究发现：(1)化学师范生对手持技术的行为意愿、感知易用性、主观规范正向影响TPACK的发展;(2)化学师范生对手持技术的感知有用性与自我效能正向影响行为意愿,并能通过行为意愿间接影响TPACK的发展。最后,基于研究结果,提出发挥示范引领作用、重视优质资源的整合应用等提升化学师范生手持技术TPACK的4条建议。     

影响化学师范生教学实践能力的主要因素及其对策

调查发现,化学师范生的教学实践能力主要受实习态度、教师指导、训练课时情况、真实课堂模拟、实习评价真实性等5个主要因素的影响。通过对成因的统计分析,提出了建立完整客观的评价体系,转变师范生对实践课程的观念,使其有一个认真的态度,加强教学模拟训练和加大实习执行力度的教学实践能力提升对策。     

中学化学教师教学诊断能力的调查研究

通过问卷调查、访谈等方法,以在职高中化学教师及在校化学专业师范生为研究对象,对化学教师教学诊断能力现状进行研究.研究发现,现阶段高中化学教师的教学诊断能力在整体上处于一个中等水平,但在不同个体之间还是存在比较大的差异.经验型教师的化学教学诊断能力要明显高于新手型教师和职前教师,同时,教师教学诊断能力也受学校层次、所处地域等客观因素影响,学生、家长、学校等对教师的高要求能在一定程度上促进教师提高教学诊断能力.当然在化学教师当中还存在理论缺乏、意识不强等问题.根据研究结果,从教师自身、学校及教育主管部门、师范院校等方面,对化学教师教学诊断能力的提高提出相应建议.     

化学师范生对概念转变教学的认识的调查研究

使用问卷调查法与访谈法,以广东省某高校的化学师范生为样本,测查了63名化学师范生对概念转变教学的认识。结果表明师范生对化学概念转变教学的含义与策略的认识仍有待加强。基于研究结果,对我国化学职前教师教育提出了相关建议。     

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%.     

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.     

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.     

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.     

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.     

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.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

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.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

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.