中学化学教学中平衡常数的价值和意义的分析

高中《化学反应原理》新增设了化学平衡常数、电离常数、盐的水解常数、溶度积常数4项内容。通过分析得出,化学中的平衡常数是经过长期实验、推演得出的综合数值,它不但蕴含着化学平衡的知识内容、科学的实验方法,同时包含着丰富的人文精神。基于此提出平衡常数的教学可以增强学生的科学本质观,培养学生的科学方法观以及人文精神,利于提高学生的科学素养。     

在化学教学中渗透科学本质教育——以“酸、碱、盐在水溶液中的电离”为例

科学史中蕴含着丰富的科学本质要素,通过科学史可以让学生更好地理解科学的本质。以"酸、碱、盐在水溶液中的电离"为例,借助科学家探索电解质电离现象的史实,能揭示"科学是一个不断探究的过程""科学是观察和推理的必然结合"等科学本质。     

Effect of Different Designs of Science History on Students' View of the Nature of Science: A Case Study on Atomic Structure

科学史是促进学生科学本质观发展的重要策略.本研究以181名高一学生为研究对象,采用准实验设计,探讨了在原子结构教学中,不同科学史设计对学生科学本质观发展的影响.结果表明:无论何种教学设计对学生科学本质观发展都有影响,但影响的方面和程度不同；采用“认识型”、“反思型”的科学史设计效果要明显优于“知识型”.     

认识论指导下的化学教学策略

什么可以被算作知识?知识是怎样发展的?知识受到哪些限制?谁拥有知识?知识的价值是什么?拥有或没有知识意味着什么?本文提出了认识论指导下的教学语言的选择、科学理论与模型教学策略、科学探究教学策略、全球化问题教学策略、科学知识的本质教学策略等,并进行了一学年的课堂教学实践,结果证明认识论指导下的科学教学有利于学生学习方式的改变,有利于培养学生的科学本质观、批判性与创造性。     

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.     

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。     

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。     

理科教师科学本质观发展策略的探索

帮助学生发展适当的科学本质观（VNOS）是科学教育的重要目标之一,而教师具有理想的科学本质观是实现这一目标的必要条件。有调查显示,现今理科教师的科学本质观基本处于较为朴素的水平,有待提高。鉴于此,本文在综合分析国内外相关研究的基础上,提出了一套符合中学理科教师实际情况的科学本质观发展策略。     

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。     

计量数比规则与等物质的量规则的比较

指出了计量数比规则存在的缺陷:不利于贯彻有关物质的量及其单位摩尔的SI规定,不能继承当量定律的数据资料,不能表示反应的性质,不能正确表达水硬度、碱度、树脂交换容量及电解定律,缺乏科学的导出过程及计量关系表达式,计算过程繁杂。而等物质的量规则继承和发展了当量定律,使整个滴定分析计算简单规范。     

锌在植物中的形态及生理作用机理研究进展

对锌在植物中的形态及锌在植物生理过程中的作用机理进行了综述和讨论,表明锌对碳水化合物代谢,蛋白质代谢,植物生长素代谢及细胞膜的功能和结构有很大影响。此外,锌与植物病害也有很大关系。     

A Study of the Kinetics of the Sulfation of 2-Octanol by Sulfamic Acid

The kinetics of the sulfation of 2-octanol by sulfamic acid in dimetylformamide were studied. The rate of disappearance of sulfamic acid obeys the rate equation: Rate=k[SA] where [SA] is the concentration of sulfamic acid. The energy and entropy of activation are 3.1 ± 0.6 kcal/mol and 15±2eu A possible mechanism is as follows: The sulfamic acid reacts with DMF to form DMF·SO₃ which then reacts rapidly with 2-octanol to form ammonium sec-octyl sulfate. The kinetics of the sulfation of 2-octanol by sulfamic acid in dimethyl sulfoxide were also studied. The reaction is described by a similar first-order equation. The energy and entropy of activation are 33.7±1.0 kcal/mol and 17±3eu.     

观念建构为本的化学教学设计研究

以提高学生的科学素养为核心的新课程向以事实为本的课堂教学设计提出了挑战,也为观念建构为本的教学设计提供了展现的平台。在王磊和范晓琼2005年"观念建构为本教学的理论研究"的基础上,提出了观念建构为本的教学设计模型。结合具体教学案例"电离平衡",对如何进行观念建构为本教学设计进行了详细阐述,并提供了电离平衡一节的教学设计。     

The calorimetric determination of the ceiling temperature for the chemical polymerization of pyrrole

The previously found strong dependence of the polymerization enthalpy on the reaction temperature has been rationalized. The temperature dependence is to be ascribed to the existence of a ‘ceiling temperature’ for the polymerization process of the pyrrole monomer. The determined ceiling temperature has beenT?350 K when FeCl₃ was used as the oxidizing agent in CH₃CN solution. The existence of a ceiling temperature together with its already determined exoenthalpic nature allows to classify the polymerization reaction as an exoentropic one. From the dependence of the yield of insoluble polymer on the reaction temperature, the trend of the relative mean numeral molecular massM _n for the different obtained polymers has been determined. Measurements of electrical conductivity on pressed pellets of the different polymers allowed to establish a correlation between theM _n value and the conductivities The dependence of the conductivity on the exposition time to the air allowed to do some essays on the aging behaviour of the obtained polypyrrole. By making some assumptions, an absolute calorimetric determination of the value ofM _n of polypyrrole was tempted together with that of the related poly-N-vinilpyrrole.     

Determination of the number of light-absorbing species in the protonation equilibra of selected drugs

The determination of the number of components in a mixture is an important tool for qualitative and quantitative analysis in spectroscopy. The accuracy of nine selected indices for an estimation of the number of components that contribute to a set of spectra was critically tested on experimental data sets of protonation equilibria of four drugs using the INDICES algorithm in S-Plus. Methods are classified into two categories: precise methods based on a knowledge of the instrumental error of the sabsorbance data, s_inst(A), and approximate methods requiring no such knowledge. Indices of precise methods predict the correct number of components, even the presence of a minor one, when the quality of data is high and instrumental error is known. Improved identification of the number of species uses the second or third derivative function for some indices, namely when the number of species in the mixture is higher than four and when, due to large variations in the indicator values even at logarithmic scale, the indicator curve does not reach an obvious point where the slope changes. The number of variously protonated components and their dissociation constants for four drugs—mycophenolate, ambroxol, silybin and silydianin—at 25 °C were determined using SQUAD(84) regression and INDICES principal component analysis of the pH-spectrophotometric data. A proposed strategy of efficient experimentation in protonation constants determination, followed by a computational strategy, is presented with the goodness-of-fit tests for various regression diagnostics enabling the reliability of parameter estimates to be accessed.     

Use of the velocity of sound in predicting the PVT relations

Thermodynamic properties of fluids are generally calculated from the PVT relations through equations of state. The majority of existing equations of state require the critical properties or intermolecular potential energy parameters as their input data. In many cases, such properties are neither available nor they can be accurately estimated.

One accessible and accurately measurable property of substances is the velocity of sound. In this report a method is introduced through which one can predict the PVT behavior of fluids using the velocity of sound data. A general mathematical relationship,

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expressing the velocity of sound, c, in terms of the hard-core velocity of sound, c_hs, and thermodynamic properties is derived. One may use this equation to extract PVT data from cVT data, or vice versa. As an example the virial coefficients, the Lennard-Jones intermolecular potential parameters, and the constants of the van der Waals equation of state for a number of pure fluids are calculated using the velocity of sound data. Utility of this method is particularly attractive for such compounds as heavy hydrocarbons, unstable fluids, and newly designed molecules for which intermolecular parameters and critical properties are not available.     

Effect of specific adsorption of anions on the kinetics of the current relaxation after pulsed anodic activation of dissolution of hydrophilic metals

Based on the model of spatial separation of the dissolution and passivation of hydrophilic metals, the effect of strong specific adsorption of anions on the shape of curves for the relaxation of anodic current of metals in acid solutions after switching an anodic activation pulse off is considered by using iron as an example.     

高等师范院校化学类专业课程体系设计与教学改革

高等师范院校化学类专业建设有其自身特有的发展历史,同时也表现出与综合类高校化学类专业所不同的办学特色。为了实现特定的人才培养目标,高师化学类专业需要形成"通识类+专业主干类+个性发展类"课程体系,同时根据不同类型学生的发展特点和需要对各个模块进行具体化设计。高师化学类专业课程教学既要体现化学学科思维,又要体现现代教育理念和方法,努力将化学学科的研究过程及其特点与学科教学过程与方法有机地整合,达到深度融合。