新手熟手初中化学教师课堂教学行为特征的比较研究*——以“酸和碱”单元教学为例

通过对新手化学教师和熟手化学教师各4节“酸和碱”单元常态课堂中教师使用教学行为链、教学行为对在时间和频次等方面的特征进行对比分析发现,在教学行为链上,新、熟手化学教师都会在较高水平的教学行为链上花费更多的时间,熟手化学教师高水平教学行为链在频次上的占比要优于新手化学教师,在不同教学行为链时间安排上的合理性要更高一些;在教学行为对上,新、熟手化学教师都多以“问”和“讲”,学生多以“答”的方式来展开课堂活动,熟手化学教师在每一次“动”和“思”上所用时间要明显高于新手化学教师,学生参与课堂的水平上,熟手化学教师要优于新手化学教师。得出如下启示:与熟手化学教师相比,新手化学教师应有效地组织和安排课堂教学行为,注重对“酸和碱”学科内容本身及其教学的驾驭。无论是熟手还是新手化学教师均应进一步给予学生课堂参与的机会。     

国外科学教师的科学本质学科教学知识研究进展述评*

梳理了国外科学教师NOS-PCK的模型组分、整体测查、影响因素及提升途径等4个方面的研究进展,并发现:NOS-PCK已有通用的模型,但其组分内涵还尚未明确;各个研究侧重于各个组分及组分整合情况的测查;影响因素还需被进一步探索;目前大致有课程培训、教学实践及阅读文献等提升途径。文末据此谈及国外已有研究对我国化学教师教育及其研究的启示。     

新手-熟手高中化学教师PCK个案比较研究* ——以“氧化还原反应”主题为例

采用访谈法与质性资料分析法,测查了6名(3名新手与3名熟手)高中化学教师关于氧化还原反应主题的PCK。结果表明:(1)新手教师与熟手教师在CTO,KoL与KoS组分上存在较明显的差异。新手教师倾向于采用“教师-传授”教学取向,对学生知识的把握相对不足,更强调使用习题巩固策略;而熟手教师倾向于采用“学生-建构”教学取向,对学生知识的把握更为全面,更强调学生自主建构知识的过程。(2)新手教师与熟手教师在KoC与KoA组分上存在较明显的相似之处。在课程知识方面,教师对课程标准与教材中氧化还原反应主题内容具有较好的理解,但对化学基本观念、学科核心素养认识尚浅;在评价知识方面,教师偏向于传统的评价方式,且集中在形成性评价和总结性评价,但相对缺乏对学生的课前诊断性评价。文末据此对我国化学教师教育及其研究提出相关建议。     

中学化学教师教学用书教学属性的调查研究

以在职高中化学教师为研究对象,采用问卷调查化学教师教学用书教学属性的使用现状。研究发现,教师教学用书在一线教师中的使用频次和深广度不高,其中女教师和新手型教师相对使用频次高。教师教学用书对教师的促进作用持中等水平,其中较好地促进了教师观念的提升。教师教学用书的内容是影响其使用的主要因素,而教师的教育理念、教研水平和知识水平是其次。基于此,从内容编写角度给出一些建议。     

新手型化学教师有效教学认识现状的调查与思考

以参加满1年教学工作的新手型化学教师为研究对象,调查其对有效教学的认识现状。研究发现,39%的新手型化学教师对有效教学特征的认识只能达到1个维度;仅8%的新手型化学教师能够达到4个及以上维度,64%的新手型化学教师能够认识到"合理设计并实现教学目标"特征。新手型化学教师对有效教学策略认识主要集中在"有效的教学设计"(50%)和"突出学生的主体地位"(53%);对有效教学影响因素认识主要集中在"教师的专业素养"和"学生的能力水平",少有提及"学生预习和课后巩固"等因素;对有效教学误区认识较窄。根据以上研究结果,对新手型化学教师和教育教学机构提出建议。     

免费师范生新手化学教师教学困惑及解决对策研究

通过总结免费师范生新手化学教师在教学中遇到的教学困惑的类型,编制调查问卷,并进行访谈,开展深度调研,明确免费师范生新手化学教师普遍存在的教学困惑和认可的解决对策,为高师院校师范生的培养、免费师范生教育硕士的课程实施及免费师范生新手教师的培训提供借鉴。     

专家-新手教师化学课堂教学对话特征的比较研究

采用专家-新手比较研究方法,对专家教师和新手教师化学课堂教学对话的内容和方式进行了比较。结果表明,专家教师的课堂对话属于“以问题为中心的互动式对话”,具体特征表现为“教师提问-学生陈述-师生质疑-共同评价”;而新手教师的课堂对话属于“以教师为中心的问答式对话”,具体特征表现为“教师提问-学生回答-教师评价”。     

专家-熟手-新手教师在化学试题命制中的差异研究——以一道工艺流程题的命制为例

专家、熟手和新手教师基于相同文献命制高中化学工艺流程题,通过试题要素分析、实测结果对比和显著性差异检验,研究专家、熟手和新手教师在化学命题上的差异及差异表现,为提升教师的命题水平提供有益的参考。     

化学师范生学科理解能力的培养研究:问题与对策*

新时代卓越教师培养对师范生的能力培养提出更高要求。以化学为例,对新手型教师学科理解能力进行调查和分析,结果显示新手型化学教师存在知识理解错误、本质思考不足、微观探析缺乏等问题。因此对化学师范生培养提出4个建议,即高校应加强化学师范生中学与大学专业课程的衔接,学科教学论教师应促进化学师范生主动进行学科理解,学科教学论教师应构建师范生学科理解的典型案例,科学开设相关课程保障师范生学科理解的学习空间。     

对化学教学论实验课程的实践及思考

在化学教学论实验课程的教学中,通过组建任课教师、化学教师教育方向研究生、本科生这样一个多层次、一体化的学习共同体,按照"两主线三阶段"的教学模式,培养教学新手的实验教学管理能力。模仿校本教研的方式,促进共同体中的教学新手对科技哲学观念指导下的化学实验教学过程所需要的教学技能进行实践性体验,从而实现化学教师的专业化发展。     

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%.     

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.     

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.     

Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirine-ring expansion

The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.     

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.