化学教材中科学本质内容表征工具的评介与应用*

理解科学本质是公民科学素养的重要组成部分,教材是帮助学生发展适当科学本质观的重要媒介。研究和表征教材中的科学本质对培养公民的科学素养具有重要的意义。详细评介了尼日利亚学者 Upahi 等人所构建的关于教材中科学本质的表征工具,包含科学本质内涵、科学本质与学科内容的关系以及科学本质的呈现方式等3个层面,并应用该工具对我国2019年颁布的鲁科版化学教材展开实验性研究。     

基于科学本质教育的化学教科书设计——以元素周期律的发现和学习为例

理解科学本质是科学教育始终追求的一个重要目标。教科书作为学校教育最主要的教材,应重视以科学史为线索,实现科学本质教育的任务。元素周期律作为化学科学重要的基本理论,它的发现过程充满了科学家的探索和智慧,蕴含着丰富的科学本质教育的素材。化学教科书的设计应充分重视这一素材,从内容和方法两个维度对学生进行科学本质教育。     

在化学微观认识学习中发展学生科学本质理解的思考

发展学生对于科学本质的理解是科学教育的一个重要目标。在化学微观认识学习中发展学生科学本质理解的基本要点是：（1）化学微观认识是建立在事实基础之上发展起来的;（2）化学微观认识属于科学理论知识,是人类建构的说明物质微观世界的可能性认识;（3）化学微观认识之所以合理是因为较为满意的从微观结构的角度解释和预测了物质的性质。发展学生科学本质理解的基本思路是：（1）以WWHW为架构对化学微观认识进行认识论思考;（2）以“横纵关照”为基本技术构建发展科学本质理解的教学目标;（3）设计具有认识论意义的教学主题;（4）通过显性话语发展科学本质理解;（5）通过反思性活动发展科学本质理解;（6）适当评价学生对于科学本质的理解。     

运用科学史培养初中生的科学本质观

通过科学教学使学生获得对科学本质的理解,建立起一定的科学本质观已越来越受到理科教育者的关注。科学本质的复杂性、丰富性决定了个人或社会对科学本质的理解与认识存在层次性和结构性。科学史教育是培养学生科学本质观的一个重要途径,如何在化学教学中运用化学史增强学生对科学本质的理解是摆在化学教育者面前的一个重要课题。从对科学本质和科学本质观的理解入手,初步确定了初中生应具有的科学本质观。通过一个具体化学教学案例的设计,介绍一种融合科学史培养学生科学本质观的化学教学模式。     

新旧高中化学课程标准中的科学本质教育内容研究*

理解科学本质是科学教育的重要目标,理科课程标准中倡导的科学本质教育对中学生科学素养发展起重要作用。本研究在构建科学本质内容、呈现方式、复杂度等三维分析框架基础上,对2003年版和2017年版高中化学课程标准中“内容标准”条目中呈现的科学本质教育内容进行纵向对比分析,发现2017年版高中化学课程标准中科学本质教育内容表现维度更全面,2版课程标准在科学本质内容上呈现方式占比皆为隐性大于显性,进阶性体现略有不足。基于此提出以下建议:挖掘科学本质教育内容载体,融合化学学科知识;加强对科学本质教育价值的认识,建立评价体系;重视科学本质内容的多维整合,体现进阶性。     

职前化学教师对“科学探究”理解水平的调查研究*

采用美国诺尔曼·莱德曼(Norman G. Lederman)和朱迪斯·莱德曼(Judith S. Lederman)编制的科学探究观(View About Scientific Inquiry, VASI)调查问卷,对38位职前化学教师的科学探究观进行了调查。结果发现,职前化学教师对科学探究的理解水平参差不齐,理解水平最好的是维度三(D3),74%的职前化学教师对该维度持“通晓的(Informed)”观点;理解水平中等的是维度二(D2),66%的职前化学教师对该维度持“混合的(Mixed)”观点;理解水平最差的是维度七(D7),61%的职前化学教师对该维度持“朴素的(Naive)”观点,并且没有人对该维度持“通晓的”观点,针对这种情况,提出3条改进策略:一是“显性化”,在课程标准和教科书中以“显性”的方式呈现有关科学探究理解的内容;二是“活动化”,教师在教学中设计并实施基于理解探究的各种实践活动;三是“反思性”,引导学生积极主动地反思科学探究活动,获取对科学探究的深入理解。     

国外小学生科学本质教学的研究综述

发展小学生对科学本质(nature of science, NOS)的理解是国际科学教育的重要目标。小学生的认知发展具有阶段性,教师应根据小学生的认知发展阶段设计符合小学生认知发展水平的NOS教学。适当的NOS教学能够改善小学生对NOS的理解,但小学生对NOS的理解较难从“素朴”水平提升到“充分”水平。后续研究应充分关注小学生的认知发展水平,结合显性-反思性教学方法以及去情境化活动和情境化活动,探索适合不同认知发展阶段小学生的更为有效的NOS教学策略。     

教科书中的元素周期律:科学本质的视角

教科书是影响学生理解科学本质的诸多因素中最重要的因素之一.知识呈现的逻辑线索、科学史内容的呈现以及语言的运用明确地表述或潜隐地渗透了特定的科学本质观.通过对不同类型高中化学教材中元素周期律呈现的比较分析,发现新版教科书更为重视学生对科学本质的理解,但由于传统沿袭、相关研究薄弱等原因,仍然没有很大突破.     

高中生微观认识学习中科学本质观的调查研究

帮助学生适当理解科学本质是科学教育的重要目标之一,也是培养学生科学素养的核心成分之一。本研究的目的是了解高中生微观学习中的科学本质观。调查表明,学生的科学本质观基本处于较为朴素的水平,对科学内容的理解基本处于了解的水平,在思维方式上几乎只考虑知识是什么和知识有什么用,很少考虑知识的产生式和合理性。影响学生科学本质观的主要因素是教师因素和课程因素。     

农村化学教师对化学核心概念理解转变的实践研究

对农村化学教师核心概念理解转变的有效方式进行了实践研究。实践研究以短期培训为基本方式,所建设的培训课程包括以“物质及其转化”为回归性问题的化学核心概念价值研讨、从科学本质观的视角考察化学微观认识、以WWHW为认识论模型反思化学核心概念的知识性质、以能量观为基本视角反思核外电子的运动特征等为基本研讨专题,以化学概念教学设计自我监控系统为指导的基于化学科学理解的教学设计实践活动等为基本内容。研究对象是来自分布于山西省各地市的农村初中化学教师52名。实践研究为期5天,共30课时。研究工具是围绕对原子存在的认同、原子概念的理解、电子层含义、原子结构示意图、化学键概念及化学键理论的理解设计的调查问卷。实践研究表明,实践前化学教师对化学核心概念的理解处于非常低的水平,实践后化学教师对核心概念的理解有了明显的转变。本实践研究所得的结论是：（1）设计合理的基于观念发展的教师教育课程,可以促进教师的专业化发展。短期专题课程培训是农村教师专业化发展的一种必要形式。（2）基于观念转变的研讨专题和以化学概念教学设计自我监控系统为指导的基于化学科学理解的教学设计实践活动等构成的课程可以有效地促进教师对化学核心概念理解的转变。     

Synthesis and structure of hydroxyisoxazolidines and derivatives of hydroxylamine and alkenals

The reactions of N-substituted hydroxylamines with alkenals serve as a method for the synthesis of the corresponding 2-substituted 3(5)-hydroxyisoxazolidines. The reaction pathway is determined by the nature of the substituent attached to the nitrogen atom. Ring-chain isomerism has been detected in these newly obtained compoundsTranslated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1270–1276, September, 1987.     

Synthesis and characterization of triazenide and triazene complexes of ruthenium and osmium

Triazenide [M(eta2-1,3-ArNNNAr)P4]BPh4 [M = Ru, Os; Ar = Ph, p-tolyl; P = P(OMe)3, P(OEt)3, PPh(OEt)2] complexes were prepared by allowing triflate [M(kappa2-OTf)P4]OTf species to react first with 1,3-ArN=NN(H)Ar triazene and then with an excess of triethylamine. Alternatively, ruthenium triazenide [Ru(eta2-1,3-ArNNNAr)P4]BPh4 derivatives were obtained by reacting hydride [RuH(eta2-H2)P4]+ and RuH(kappa1-OTf)P4 compounds with 1,3-diaryltriazene. The complexes were characterized by spectroscopy and X-ray crystallography of the [Ru(eta2-1,3-PhNNNPh){P(OEt)3}4]BPh4 derivative. Hydride triazene [OsH(eta1-1,3-ArN=NN(H)Ar)P4]BPh4 [P = P(OEt)3, PPh(OEt)2; Ar = Ph, p-tolyl] and [RuH{eta1-1,3-p-tolyl-N=NN(H)-p-tolyl}{PPh(OEt)2}4]BPh4 derivatives were prepared by allowing kappa1-triflate MH(kappa1-OTf)P4 to react with 1,3-diaryltriazene. The [Os(kappa1-OTf){eta1-1,3-PhN=NN(H)Ph}{P(OEt)3}4]BPh4 intermediate was also obtained. Variable-temperature NMR studies were carried out using 15N-labeled triazene complexes prepared from the 1,3-Ph15N=N15N(H)Ph ligand. Osmium dihydrogen [OsH(eta2-H2)P4]BPh4 complexes [P = P(OEt)3, PPh(OEt)2] react with 1,3-ArN=NN(H)Ar triazene to give the hydride-diazene [OsH(ArN=NH)P4]BPh4 derivatives. The X-ray crystal structure determination of the [OsH(PhN=NH){PPh(OEt)2}4]BPh4 complex is reported. A reaction path to explain the formation of the diazene complexes is also reported.     

Mass and NMR spectra of haplophyllidine and perforine and of their derivatives

Conclusions The mass and NMR spectra of haplophyllidine, perforine, and their derivatives have been studied. The influence of the open and cyclic forms of the molecular ion on the nature of the fragmentation has been discussed. The main routes of fragmentation of the compounds considered are due to the presence of substituents at C₈ and C₄.Khimiya Prirodnykh Soedinenii, Vol. 5, No. 4, pp. 273–279, 1969     

Investigation of adhesion and mobility of polyurethane and epoxy-rubber glues and adhesives

The values of activation parameters in uncured and cured epoxy resins, rubbers, and blends thereof are investigated. The dependences of activation energy and adhesion strength of epoxy-rubber compositions on rubber content are determined. The correlation of adhesion and activation energy values for polyurethane rubber and epoxy-rubber compositions is shown.     

Crystal and molecular structure of aroyl- and acetylhydrazones of acet- and benzaldehydes

Aroyl- and acetylhydrazones of acet- (I) and benzaldehydes (IV) and benzoylhydrazones of acet- (II) and benzaldehydes (III) were studied by x-ray structural and quantum-chemical methods in order to establish their structures. Compund (I) was the EEZ structure in the crystal. Calculations and spectral data showed that the EEE form occurs in nonpolar solvents and in the gas phase. According to crystallographic data molecules (I)–(IV) are the E-isomers (relative to the N-N bond) and the hydrazone fragments are planar. Intermolecular N-H...O H-bonds from in the crystals. The data obtained suggest that the majority of acylhydrazones are conformationally rigid on dissolution although exceptions do occur. Apparently the reasons for the difference of acetyl- and benzoylhydrazones in electrocarboxylation reactions are electronic and not steric factors.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 75–81, January, 1991.     

Preparation and characterization of diarylphosphazene and diarylphosphinohydrazide complexes of titanium, tungsten and ruthenium and phosphorylketimido complexes of rhenium

Reaction of the proligand Ph2PN(SiMe3)2 (L1) with WCl6 gives the oligomeric phosphazene complex [WCl4(NPPh2)]n, 1 and subsequent reaction with PMe2Ph or NBu4Cl gives [WCl4(NPPh2)(PMe2Ph)] (2) or [WCl5(NPPh2)][NBu4] (3), respectively. DF calculations on [WCl5(NPPh2)][NBu4] show a W=N double bond (1.756 A) and a P-N bond distance of 1.701 A, which combined with the geometry about the P atom suggests, there is no P-N multiple bonding. Reaction of L1 with [ReOX3(PPh3)2] in MeCN (X = Cl or Br) gives [ReX2(NC(CH3)P(O)Ph2)(MeCN)(PPh3)](X = Cl, 4, X = Br, 5) which contains the new phosphorylketimido ligand. It is bound to the rhenium centre with a virtually linear Re-N-C arrangement (Re-N-C angle = 176.6 degrees, when X = Cl) and there is multiple bonding between Re and N (Re-N = 1.809(7) A when X = Cl). The proligand Ph2PNHNMe2(L2H) reacts with [(C5H5)TiCl3] to give [(C5H5)TiCl2(Me2NNPPh2)] (6). An X-ray crystal structure of the complex shows the ligand (L2) is bound by both nitrogen atoms. Reaction of the proligands Ph2PNHNR2[R2 = Me2 (L2H), -(CH2CH2)2NCH3 (L3H), (CH2CH2)2CH2 (L4H)] with [{RuCl(mu-Cl)(eta6-p-MeC6H4iPr)}2] gave [RuCl2(eta6-p-MeC6H4iPr)L] {L = L2H (7), L3H (8), L4H (9)}. The X-ray crystal structures of 7-9 confirmed that the phosphinohydrazine ligand is neutral and bound via the phosphorus only. Reaction of complexes 7-9 with AgBF4 resulted in chloride ion abstraction and the formation of the cationic species [RuCl(6-p-MeC6H4iPr)(L)]+ BF4- {(L = L2H (10), L3H (11), L4H (12)}. Finally, reaction of complex 6 with [{RuCl(mu-Cl)(eta6-p-MeC6H4iPr)}2] gave the binuclear species [(eta6-p-MeC6H4iPr)Cl2Ru(mu2,eta3-Ph2PNNMe2)TiCl2(C5H5)], 13.     

Ti-V基储氢合金及其氢化物的物相结构与组分优化设计

Ti-V基储氢合金在室温、常压下即可表现出良好的储氢特性,且质量储氢容量明显高于传统AB₅型储氢合金,从而在氢气的精制和回收、运输和储存及热泵等方面有较早的应用。 此外,在混合气体分离、核反应堆中处理氢的同位素、镍氢电池及燃料电池负极材料等方面也得到了广泛的研究与关注。 基于目前Ti-V基储氢合金的研究现状,概述了该类合金的优势、限制性因素(包括成因)及改性手段。 此外,为了进一步理解Ti-V基合金储氢机理、构建合金组分与储氢特性之间的对应关系,本工作重点围绕Ti-V基储氢合金及其氢化物的结构、组分优化设计展开综述,并对其未来研究方向做出展望。     

Kinetics and mechanisms of chlorine dioxide and chlorite oxidations of cysteine and glutathione

Chlorine dioxide oxidation of cysteine (CSH) is investigated under pseudo-first-order conditions (with excess CSH) in buffered aqueous solutions, p[H+] 2.7-9.5 at 25.0 degrees C. The rates of chlorine dioxide decay are first order in both ClO2 and CSH concentrations and increase rapidly as the pH increases. The proposed mechanism is an electron transfer from CS- to ClO2 (1.03 x 10(8) M(-1) s(-1)) with a subsequent rapid reaction of the CS* radical and a second ClO2 to form a cysteinyl-ClO2 adduct (CSOClO). This highly reactive adduct decays via two pathways. In acidic solutions, it hydrolyzes to give CSO(2)H (sulfinic acid) and HOCl, which in turn rapidly react to form CSO3H (cysteic acid) and Cl-. As the pH increases, the (CSOClO) adduct reacts with CS- by a second pathway to form cystine (CSSC) and chlorite ion (ClO2-). The reaction stoichiometry changes from 6 ClO2:5 CSH at low pH to 2 ClO2:10 CSH at high pH. The ClO2 oxidation of glutathione anion (GS-) is also rapid with a second-order rate constant of 1.40 x 10(8) M(-1) s(-1). The reaction of ClO2 with CSSC is 7 orders of magnitude slower than the corresponding reaction with cysteinyl anion (CS-) at pH 6.7. Chlorite ion reacts with CSH; however, at p[H+] 6.7, the observed rate of this reaction is slower than the ClO2/CSH reaction by 6 orders of magnitude. Chlorite ion oxidizes CSH while being reduced to HOCl, which in turn reacts rapidly with CSH to form Cl-. The reaction products are CSSC and CSO3H with a pH-dependent distribution similar to the ClO2/CSH system.