欧洲PARSEL化学资源包及其启示

PARSEL计划是欧洲正在实行的一个科学课程改革计划,其目的是为了提高科学课程对于学生科学素养的普及性和相关性。PARSEL计划的开发与实施模式对我国课程改革与校本课程开发有极重要的参考价值。主要介绍该计划以及其中化学部分的资源包,并针对该计划的特点对我国课改提出一些建议,以供参考。     

美国“国家科学教育标准”中的科学素养探微

培养未来公民的科学素养已成为世界各国理科课程改革的首要目标.本文试图以美国“国家科学教育标准“中的“科学内容标准“为依据探讨科学素养的基本含义和内容.文章讨论了该文件中的科学素养与一般科学教育目标的关系,并在以下6个方面对科学素养的内容作了介绍和分析:作为探究的科学、科学学科内容、科学和技术、个人和社会视野的科学、科学的历史和本质、统一的科学概念和过程.     

美国“国家科学教育标准”中的科学素养探微

培养未来公民的科学素养已成为世界各国理科课程改革的首要目标。本文试图以美国“国家科学教育标准”中的“科学内容标准”为依据探讨科学素养的基本含义和内容。文章讨论了该文件中的科学素养与一般科学教育目标的关系,并在以下 6个方面对科学素养的内容作了介绍和分析:作为探究的科学、科学学科内容、科学和技术、个人和社会视野的科学、科学的历史和本质、统一的科学概念和过程。     

美国"国家科学教育标准"中的科学素养探微

培养未来公民的科学素养已成为世界各国理科课程改革的首要目标。本文试图以美国“国家科学教育标准”中的“科学内容标准”为依据探讨科学素养的基本含义和内容。文章讨论了该文件中的科学素养与一般科学教育目标的关系,并在以下6个方面对科学素养的内容作了介绍和分析：作为探究的科学、科学学科内容、科学和技术、个人和社会视野的科学、科学的历史和本质、统一的科学概念和过程。     

高中化学科学方法教育现状调查与问题对策

20世纪70年代后,世界各国开始进行基础教育课程改革,通过加强科学教育以全面提高科学素养, 科学方法作为科学素养中的核心要素在教育中得到了空前的重视。     

中学化学教师科学素养的现状调查

科学素养的构成要素国内外学者已有不同的界定。培养学生的科学素养是中学化学课程的主要目标,教师科学素养的高低将直接影响课程改革实施的质量。本文对皖中地区中学化学教师科学素养的现状进行了调查与分析,并提出了一些建议。     

高中生科学素养现状调查研究

提高学生科学素养是课程教学改革的一项重要内容。从科学素养所涵盖的科学内容、科学本质和科学-技术-社会(STS)3个维度出发,采用南非学者Laugksch and Spargo(1996)编制、赖小琴(2007)修订的基本科学素养问卷(TBSL)为测量工具,对贵州少数民族(苗族、布依族、仡佬族)高中生的科学素养现状进行调查,依据研究结果提出了培养和提高贵州少数民族高中生科学素养的建议。     

初中"科学"课堂中学生学习行为的特征及其影响因素

从综合科学课程改革实验区的"科学"课堂入手,运用质化的研究方法对学生的学习状态及学习行为进行观察分析和总结,进而阐述"科学"课中学生学习行为的主要特征,以及影响学生学习行为的主要因素.希望通过对"科学"课堂的观察与思考给目前的理科教学提供一定的启示,使学生养成良好的学习行为,更好的促进学生科学素养全面的、主动的发展.     

无机及分析化学实验课程中学生创新能力培养探索

无机及分析化学实验课程是化学本科生的必修实验课,在本科生科研能力和创新能力培养中有着极其重要的作用。通过对课程内容、教学形式和开放模式进行改革探索,除加强基本操作和基本技能训练外,通过综合性基础实验和开放实验模式,启迪学生的创新思维,激发学生的创新激情,培养学生的科学素养和探索精神。     

高中生化学科学素养测查的初步探索

当今,我国基础教育课程改革越来越重视培养学生的科学素养。但尚缺乏较为完善的评价体系与学生科学素养的培养相匹配,急需进行相关的评价研究。通过具体的实践,对高中生化学科学素养的测查进行了初步探索,界定了高中生化学科学素养的基本维度和具体内容,总结了测查的基本程序和注意问题,取得了可信的初步结论。     

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.