从文物中学化学——铁、铜性质主题式复习教学设计与实施

选择"铁、铜性质主题式复习"为案例,以铁器和铜器文物为主题背景,将铁、铜性质的复习与文物知识的介绍结合起来,使学生在学习过程中主动建构知识,在复习化学知识的同时,接触了一些文物知识,拓宽了视野,激发了学习兴趣。     

铁及其化合物教学开放性与实效性的研究

铁及其化合物是中学化学重要的元素化合物知识。新课标理念下的化学教学活动不同于传统的课堂教学。创建开放的学习环境可以激发学生学习化学的兴趣,帮助学生了解科学探究的基本过程和方法,培养学生的科学探究能力,使学生获得进一步学习和发展所需的化学基础知识和基本技能;引导学生认识化学在促进社会发展和提高人类生活质量方面的重要作用,通过化学学习培养学生的合作精神和社会责任感。开放性的教学不应该是教学表面的热热闹闹,而应该以提高教学的实效性为目的。课题组根据新的课程标准,在铁及其化合物的教学中进行了以提高教学实效性为目的的开放性教学的研究。本文叙述了本课题研究的目的、研究过程与分析、研究成果等。     

基于三重表征的实验教学——以铁的吸氧腐蚀为例

传统的铁吸氧腐蚀实验耗时长,现象不明显,课堂演示效果差。利用U型管及灵敏电流表等装置对教材中铁的吸氧腐蚀实验进行改进,并且结合原理分析完整地呈现了铁的吸氧腐蚀的宏观现象、微观本质和符号表征,丰富了学生对该部分知识的认知。研究结果表明基于三重表征的实验教学能够促进学生成绩的提高。     

基于真实情境的项目式教学在高三复习课的应用——轧钢厂废水分析处理

针对高三学生在解题和解决实际问题中缺乏对知识的整合和系统运用这一问题,围绕真实情境下的轧钢厂废水分析处理展开项目式教学。通过引导学生剖析项目任务中的化学知识和化学问题,以铁及其化合物的知识作为主线复习内容,将高中化学多个模块的知识进行结构化整合。拓宽学生认识化学问题的角度和深度,促进学生学习的热情和思维方式的转变,让化学学科核心素养得到落实。     

中学生化学学习困难的知识类型及认知分析

从化学学科知识特点来看,导致学生化学学习困难的知识包括专属知识、惰性知识、抽象知识和陌生知识4种类型。依据知识学习的信息加工理论,造成学生化学学习困难的认知因素主要包括学生的抽象概括能力不足、缺乏定量的思维方式、认知超负荷和技能尚未自动化等。     

研究性学习中学生的学习行为分析

教学活动设计的核心问题是引导学生的学习行为,从而促进学生心理的发展。对学生的学习行为的分析可以了解学生在研究过程中对自己知识框架的构建和整合过程,以及对研究性学习目的所达到的程度。本文从学生的特征、学习风格、研究小组的分工合作、学生信息来源等方面对研究性学习中学生学习行为进行了粗略的分析。     

我国2001-2013年中学化学实验学习研究热点的知识谱图

为比较准确地了解国内中学化学实验学习研究的热点和重点,为今后中学化学实验学习研究提供有力的数据与支撑,利用bicomb1.0软件与IBM SPSS20.0软件,对从中国知网中查询到的2001-2013年的518篇关于实验与化学学习的相关文献进行了知识谱图的绘制.研究结果表明,我国中学化学实验学习的研究主要涉及4大领域,分别是:高中新课程,化学实验对于化学知识的学习、素质教育,创新、观察等能力的培养等相关领域研究热点;中学化学实验对于激发学生兴趣、培养学生动手能力和课外活动作为化学教学的一种方法途径的研究热点;课堂教学中,实验教学与多媒教学等教学模式的改革、创新提升教学质量的研究热点;采用化学实验微型化、绿色化等策略来强化对学生的能力的培养.     

引导学生运用元素化合物认识模型解决实际问题的教学研究——以“菠菜补铁是真的吗”探究教学为例

针对常规元素化合物教学中的问题和学生学习的现状,设计了基于元素化合物认识模型的金属及其化合物单元复习教学。以"评估菠菜补铁是真的吗"为核心任务,突出了研究元素化合物的认识角度——化合价和物质类别;以探究实验为手段,将铁元素的定性检测和定量测定相结合,用模型拆解了一个真实、复杂的生活问题。结果表明,模型的应用有利于学生建立系统性思维,有利于学生用化学知识解决实际问题,有利于突破学生认知的障碍点,从而提高学生解决问题的能力。     

“铝及铝的化合物”教学设计

1指导思想及理论依据物质是化学学科的研究对象,元素化合物知识是化学学习的重要内容。新课程中元素化合物知识的编排较以往有了很大的改变,在必修1的阶段,主要是让学生建立以单一元素为核心的知识网络,为学生建立关于物质性质的感性认识,建立元素观、分类观和转化观等基本学科观念,为学生学习元素周期律及物质结构的相关知识奠定基础。     

高三化学专题复习的新型探究教学设计——以“高考题是怎样炼成的”为例

针对北京市高考化学对学生能力的考查要求,结合高三学生化学学习的实际情况,围绕"铁及其化合物"的核心知识设计新型探究教学专题。引导学生在课堂解决实际问题的过程中,体会高考"考什么-怎样考-怎样答",体现高考题的生成性和问题解决的策略性,提高学生解决问题的能力,提升学生的思维水平。     

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.     

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.