高中化学教学中实施STS教育的尝试

STS(科学—技术—社会 )课程通过交叉学科来促使学生理解和认识科学、技术和社会之间的相互联系。它有利于提高学生科学素养、培养学生科学精神 ,是一门有相当生命力的课程。我们学校从 1998年起 ,组织部分教师学习、研究、领会STS教育的基本精神和内涵 ,并成立了STS课题研究小组 ,并于 1999年 8月在学校部分年级进行STS课程的实践。1　STS教育的实践与探索1.1　必修课渗透 ,激发学生兴趣 ,培养科学意识课堂是渗透社会中的科学与技术的最佳场所 ,当学生看见所学知识在许多方面都有应用时 ,就会涌现出一股强烈的求知欲望 ,在化学学习中…     

理、化、生不同专业大学生关于能量概念的认识现状研究

能量概念是科学教育的一个核心概念,也是近年来国际科学教育研究的一个热点话题。在柳秀峰、Wilson等人的研究基础上,构建了能量概念的认识模型。基于该模型,并结合国内物理、化学和生物等不同专业的中学、大学教材中涉及的能量相关概念,笔者编制了调查问卷,对北京师范大学物理、化学和生物等不同专业的共280名大学生进行了测查和访谈。通过Rasch模型和SPSS统计分析发现,不同学科背景的学生对能量概念的认识角度和水平存在差异,而且存在一些偏差认识。基于学生的认识现状,笔者最后构建了关于能量概念认识的难度进阶,并对能量概念的教学提出了建议。     

基于STEM教学理念的分析化学实验教学新模式探索——以“自来水硬度测定”为例

STEM是一种集科学、技术、工程、数学多学科融合的项目式教育理念,旨在通过融合多学科知识完成项目目标,从而培养学生提出问题、分析问题以及解决问题的能力,进而激发学生的科学探索精神和创新思维能力,已经成为当前国际教育研究和改革的热点。本文将STEM教育理念引入分析化学实验教学过程中,探索发展分析化学实验课程教学新模式。倡导以学生为中心、以真实问题为牵引,学生以相关课程理论为线索,自主完成实验方案设计、实验过程、实验结果分析等一系列分析化学实验过程,从而培养学生的科学探索与实践能力。主要从课程内容、教学方法以及考核方式等三个方面来探索分析化学实验教学新模式,进而提高分析化学实验的教学质量和学生的学习兴趣和科学素养。     

基于GR编码的学生论证活动过程分析——以“化学教学论实验”教学为例

论证教学是当前国际科学教育教学的热点领域。论文采用准实验设计,使用混合研究方法,在“化学教学论实验”课程中对学生进行了为期一学期的教学实践过程。实验组开展论证式教学的实践活动,并采用GR编码方式细致地分析学生科学论证活动的过程。研究结果表明,论证教学可以显著提高化学师范生的科学论证能力,并提高化学实验课程的学习兴趣。     

九年级化学STS课程资源开发与利用的调查研究

作为当前国际理科教育改革的潮流和热点,STS教育是科学教育与人文教育相融合的一种产物,也是我国中学化学教育改革的重要课题和方向。结合九年义务教育化学课程特点对STS课程资源的开发利用进行了调查研究和实践研究,目的是为化学教师在教学中开发和利用STS课程资源提供参考。     

IB考试及其化学试题评析

IB课程是由国际文凭组织为高中生设计的为期2年的国际教育课程。通过对IB考试及其化学试题的相关介绍,分析IB化学试题的整体特征,以期能为学习国际教育课程的学生、教授国际教育课程的教师以及我国的化学基础教育改革提供一些有益的参考。     

美国《化学教育》"Research: Science And Education"专栏载文的调研

调阅、梳理了美国《化学教育》"研究:科学与教育"专栏的载文,分析了国际化学教育研究所体现出的关注学生概念学习、注重学习过程、重视改进研究方法的发展趋势。     

将教师的科学本质观转化到课堂实践——国际文献综述

提高学生的科学本质观是国际科学教育的重要目标，教师在提高学生科学本质观的过程中发挥着重要作用。本研究在梳理国际科学本质教育文献的基础上，聚焦教师的科学本质观到课堂实践的转化。研究发现，教师的科学本质观无法自动转化为有效的课堂实践，影响“转化”的因素可从教师、学生和教材等3方面进行分析，最后从职前教师和在职教师的角度综述了促进“转化”的措施。     

化学教育硕士研究生的科学本质观研究*——基于对科普微视频的分析

以构建的科学本质要素框架作为分析工具,研究学生经科普微视频分析所呈现的科学本质观。结果表明,学生无法全面、深入分析视频呈现的科学本质,反映了局限的科学本质观,而经过讨论与汇报能在一定程度上提升其科学本质观。据此,为化学教育硕士研究生的培养工作提出3点建议,即将科普微视频作为科学本质教育的素材,促进学生形成完整且深刻的科学本质观,发展学生准确抽提课程资源中的科学本质的能力。     

中学化学史教育综述

重视科学史教育,把科学的思想观、典型事例、演变发展过程融入科学课程和科学教学之中,已成为当代科学教育发展的一大特点.从化学史教育功能的认识和化学史教育的形式、途径与方法2方面分析了国内中学化学史教育状况,对我国中学化学史教育进行了反思,从中得到了一些启示.     

Determination of the enthalpy of fusion of K<Subscript>3</Subscript>TaO<Subscript>2</Subscript>F<Subscript>4</Subscript> and KTaF<Subscript>6</Subscript>

Areas of fusion and crystallization peaks of K₃TaO₂F₄ and KTaF₆ were measured using the DSC mode of a high-temperature calorimeter (SETARAM 1800 K). On the basis of these quantities, considering the temperature dependence of the calorimeter sensitivity, values of the fusion enthalpy of K₃TaO₂F₄ at the fusion temperature of 1181 K of (43 ± 4) kJ mol⁻¹ and of KTaF₆ at the fusion temperature of 760 K of (8 ± 1) kJ mol⁻¹ were determined.     

2,4‐Di­nitro­phenyl­hydrazones of 2,4‐di­hydroxy­benz­aldehyde, 2,4‐di­hydroxy­aceto­phenone and 2,4‐di­hydroxy­benzo­phenone

In 2,4‐di­hydroxy­benz­aldehyde 2,4‐di­nitro­phenyl­hydrazone N,N‐di­methyl­form­amide solvate {or 4‐[(2,4‐di­nitro­phenyl)­hydrazono­methyl]­benzene‐1,3‐diol N,N‐di­methyl­form­amide solvate}, C₁₃H₁₀N₄O₆·C₃H₇NO, (X), 2,4‐di­hydroxy­aceto­phenone 2,4‐di­nitro­phenyl­hydrazone N,N‐di­methyl­form­am­ide solvate (or 4‐{1‐[(2,4‐di­nitro­phenyl)hydrazono]ethyl}benzene‐1,3‐diol N,N‐di­methyl­form­amide solvate), C₁₄H₁₂N₄O₆·C₃H₇NO, (XI), and 2,4‐di­hydroxy­benzo­phenone 2,4‐di­nitro­phenyl­hydrazone N,N‐di­methyl­acet­amide solvate (or 4‐­{[(2,4‐di­nitro­phenyl)hydrazono]phenyl­methyl}benzene‐1,3‐diol N,N‐di­methyl­acet­amide solvate), C₁₉H₁₄N₄O₆·C₄H₉NO, (XII), the molecules all lack a center of symmetry, crystallize in centrosymmetric space groups and have been observed to exhibit non‐linear optical activity. In each case, the hydrazone skeleton is fairly planar, facilitated by the presence of two intramolecular hydrogen bonds and some partial N—N double‐bond character. Each molecule is hydrogen bonded to one solvent mol­ecule.     

“蒸馏酒”还是“发酵酒”——对《科学史导论》中“spirits” 和“distillation”的再思考

科学史奠基者乔治·萨顿在《科学史导论》第二卷的第一部分对我国宋代酿酒著作《北山酒经》予以了简要描述,出现了“spirits”“distillation”等字样;而《北山酒经》被众多学者认为其描述对象是发酵酒(黄酒)。本文从东西方蒸馏技术和相关著作的文本分析对《科学史导论》中提及的蒸馏技术和蒸馏酒存在的可能性提出了质疑。     

Projection of the liquidus surface of the Sb<Subscript>2</Subscript>Te<Subscript>3</Subscript>-Gd<Subscript>2</Subscript>Te<Subscript>3</Subscript>-Bi<Subscript>2</Subscript>Te<Subscript>3</Subscript> system

Phase equilibria in the Sb₂Te₃-Gd₂Te₃-Bi₂Te₃ ternary system have been studied using differential thermal analysis, namely, X-ray powder diffraction, microstructure examination, thermodynamic analysis, and microhardness and alloy density measurements. Phase diagrams of some polythermal joins and liquidus surface have been constructed. The regions of primary crystallization of phases and the coordinates of all invariant and univariant equilibria in the system under investigation have been established.     

Crystal structure of the synthetic analog of radtkeite Hg<Subscript>3</Subscript>S<Subscript>2</Subscript>Cl<Subscript>1.00</Subscript>I<Subscript>1.00</Subscript>

The results of structural studies of the synthetic analog of the radtkeite mineral Hg₃S₂Cl_1.00I_1.00 are analyzed. The crystal structure of the compound has been refined; the unit cell parameters are a _m = 16.827(4) , b _m = 9.117(1) , c _m = 13.165(5) , = 130.17(2)°, V = 1543.3(8) ³, space group C2/m, Z = 8, R = 0.0527. A possible transition a ₀ = a _m; b ₀ = a _m + 2c _m; c ₀ = –b _m to the pseudo-orthorhombic F cell previously determined for radtkeite, where one of the angles ( ₀ ) is slightly different from 90° (89.55°), has been found. Each sulfur atom in the structure is bonded to three mercury atoms, forming SHg₃ umbrellas with distances 2.240(6) –2.474(8) and angles HgSHg 94.7(2)°–102.9(2)°. The SHg₃ fragments are linked through Hg vertices to form corrugated [Hg₁₂S₈] layers. The halogen atoms lie inside and between the [Hg₁₂S₈] layers; the distances are Hg-Cl and Hg-I 2.783(7) , 2.961(7) , and 3.083(4) –3.311(3) , respectively.Original Russian Text Copyright © 2004 by N. V. Pervukhina, S. V. Borisov, S. A. Magarill, D. Yu. Naumov, V. I. Vasiliev, and B. G. NenashevTranslated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 4, pp. 755–758, July–August, 2004.This revised version was published online in April 2005 with a corrected cover date.     

Physicochemical foundations of synthesis of new ferromagnets from chalcopyrites A<Superscript>II</Superscript>B<Superscript>IV</Superscript>C<Stack><Subscript>2</Subscript><Superscript>V</Superscript></Stack>

The results of studying phase equilibria of ternary A^IIB^IVC^V systems have been reported. Physicochemical foundations have been developed for the synthesis of new ferromagnets with Curie temperatures above room temperature structurally compatible with basic semiconducting materials. Methods of synthesis and physicochemical properties of manganese-doped A^IIB^IVC₂^V ferromagnets have been described. The results of theoretical simulation of magnetic properties have been considered and basic approaches to the explanation of the emergence of ferromagnetism in A^IIB^IVC₂^V doped with 3d metals have been surveyed. The most promising ways to produce and study dilute magnetic semiconductors as spintronics materials have been presented.     

Calculations of thermodynamic stability of CpCoC<Subscript>2</Subscript>B<Subscript>9</Subscript>H<Subscript>11</Subscript> cobaltacarborane isomers

Quantum-chemical calculations of the geometry and energies of nine possible isomers of 12-vertex cobaltacarborane CpCoC₂B₉H₁₁ (1) were carried out by the DFT method (PBEPBE/DGDZVP/DGA1). Thermodynamic stability of the isomers increases with increasing distance between the carbon atoms in the cage and is virtually independent of the position of the CpCo vertex. The relative stabilities of the 1,2,3-(17.57 kcal mol⁻¹), 1,2,4-(3.72 kcal mol⁻¹), and 1,2,9-isomers of 1 (0 kcal mol⁻¹) are similar to the corresponding values for the ortho (17.61 kcal mol⁻¹), meta (3.21 kcal mol⁻¹), and para isomers (0 kcal mol⁻¹) of carborane C₂B₁₀H₁₂. The results of the present study confirm a close similarity of the CpCo and BH fragments in metallacarborane chemistry. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1557–1559, July, 2005.     

Influence of composition on corroding process of Na<Subscript>2</Subscript>O-K<Subscript>2</Subscript>O-CaO-ZrO<Subscript>2</Subscript>-SiO<Subscript>2</Subscript> glasses

The corroding process of six glasses of the Na₂O-K₂O-CaO-ZrO₂-SiO₂ system with ZrO₂content 0–2.13 mass % by water was observed during static tests at 121°C and pressure of 0.25 MPa in steam sterilizer. Significant increase of Na⁺ and K⁺ content in leachates was observed after the addition of ZrO₂ into glass. Further increase of the content of ZrO₂ in glasses slowed down the rate of Na⁺ and K⁺ leaching. The leaching process of SiO₂ as well as Na⁺, K⁺, and Ca²⁺ ions was evaluated on the basis of comparison with model leaching processes. Variation of the concentrations of Na⁺, K⁺, Ca²⁺, and SiO₂ in leachates with time was described by empirical equation. Observed changes in the initial leaching rates of Na⁺, K⁺, Ca²⁺, and SiO₂ can be ascribed to the content of ZrO₂ in glasses. The presence of ZrO₂ in glasses reduced the overall rate of glass dissolution.     

Determination of the enthalpy of fusion of K<Subscript>3</Subscript>NbO<Subscript>2</Subscript>F<Subscript>4</Subscript>

Areas of fusion and crystallization peaks of K₃NbO₂F₄ were measured using the DCS mode of a high-temperature calorimeter (SETARAM 1800 K). On the basis of these quantities, considering the temperature dependence of the calorimeter sensitivity, the value of the fusion enthalpy of K₃NbO₂F₄ of (98 ± 6) kJ mol⁻¹ was determined at the fusion temperature of 1257 K.     

Ionic conduction of a high-temperature modification of Lu<Subscript>2</Subscript>Ti<Subscript>2</Subscript>O<Subscript>7</Subscript>

A nanoceramic product of the composition Lu₂Ti₂O₇ is synthesized by a coprecipitation method with a subsequent sublimation drying and an annealing at 650–1650°C. The conduction of Lu₂Ti₂O₇ synthesized at 1650°C is ionic (10^–3 S cm^–1 at 800°C). Thus, a new material with a high ionic conduction has been discovered. The ordering in Lu₂Ti₂O₇ is studied by methods of RFA, RSA, IK spectroscopy, electron microscopy, and impedance spectroscopy. The existence of a low-temperature phase transition fluorite-pyrochlore at 800°C and a high-temperature conversion order-disorder at 1650°C are established.Translated from Elektrokhimiya, Vol. 41, No. 3, 2005, pp. 298–303.Original Russian Text Copyright © 2005 by Shlyakhtina, Ukshe, Shcherbakova.