从证据推理视角对“离子反应”教学案例的分析及其启示*

证据推理是学生以其经验为基础、问题为起点,根据教师提供的一个或几个学习材料(已知判断),得出目标概念(新判断)的深度思维过程。通过梳理和界定证据推理的概念、证据类型、证据推理过程及核心要素,建构出实验探究教学中以“问题、解释、假设、证据、推理、结论”为要素及其之间关系的证据推理线形模型和循环模型,以此分析视角及其框架对“离子反应”教学中证据推理的过程进行了分析,并基于证据推理的6要素得出培养学生证据推理能力的启示与建议,达到证据推理过程中基本思想方法的外显,落实证据推理与模型认知的化学学科核心素养,也为今后的教学实践提供核心推理思路及教学建议。     

“素养为本”的化学课堂教学*——以“原子晶体”为例

基于“素养为本”视角,以“原子晶体”的教学为例,对教学主题内容、教学现状及学情进行分析;以发展学生化学学科核心素养为主旨确定教学目标;以“微粒-微粒间的相互作用-物质的聚集状态-物质性质”的认识思路为主线,以“模型认知,建构概念-证据推理,归纳性质-微观探析,探究结构-科学史实,揭示价值”的任务型教学流程,达到落实并发展学生化学学科核心素养的目的。     

从化学学科核心素养到学生学习活动*——基于证据推理与模型认知的“空气”教学

以学生活动为载体,借助表现性评价,有助于学生学科核心素养的形成。根据“表现性评价”和“证据推理与模型认知”的内涵,从“获取推理证据”“基于证据推理”“建立认知模型” “基于模型认知”等4个维度提出表现性评价量规,以 “空气”第1课时教学内容为例,设计表现性任务。介绍了在“空气”第1课时的教学中,教师在课堂上基于表现性评价观测学生课堂表现,并根据学生素养达成情况及时调整教学,展开“教、学、评”一体化的教学过程。     

基于证据的推理:内涵、意义及培养路径

基于证据的推理，是在掌握证据的基础上推理出新的知识和原理。基于证据的推理对于科学发展、学生的学习及其发展具有重要意义。教学中培养学生基于证据推理的思维方式的途径有：唤醒证据为本的本能，萌发收集证据的意识；学会科学推理的技巧，自发进行合情的推理；分享证据推理的成果，体验证据推理的快乐等。     

“证据推理”在高考化学试题(全国卷)中的考查特点*

基于《普通高中化学课程标准(2017年版2020年修订)》提出的化学学科核心素养中“证据推理”的内涵及相关研究,将“证据推理”化学学科核心素养进一步解构为 “证据解读”“证据与结论的关系”“证据评估”等3个要素,并将证据按其呈现形式划分为反应机理、实验数据、工艺流程和实验方案等4种类型,在此基础上构建了“证据推理”视角下的试题分析框架,并以近5年高考化学试题(全国卷)为研究对象,总结其考查特点与规律,进而为改进化学教学提出相关建议。     

基于化学学科核心素养的初高中衔接教学——初三化学“金属的化学性质”

“金属的化学性质”是初高中化学学习的重要内容,该部分内容涉及到重要的化学观念和化学学科核心素养,如元素观、转化观、微粒观、STS观,以及宏观辨识与微观探析、证据推理与模型认知素养。但是初三学生认知水平受限,在教学中不能深入电子转移的微观角度,不能充分认知模型、应用模型。为弥补这一问题,本研究基于化学学科核心素养,进行“金属的化学性质”的初高中衔接教学研究。     

基于学科理解的“物质成分”大概念教学*

以“物质成分”大概念教学为例,基于学科理解,以探究物质成分的相关化学史为线索设计教学,引导学生在追溯“物质成分”相关概念、理论的发展过程中,逐渐建构物质成分的宏观、微观、宏微结合视角。并在解决探究物质成分的真实问题的过程中,培养学生基于证据进行推理的科学论证能力,通过认识视角的发展,体会科学理论是在不断发展和进阶的,初步建立科学发展观。     

基于证据推理与模型认知的主题式复习*—以“水的主题式复习”为例

以“水”为载体,引领学生构建判断化合物组成、推断化合物性质、常见气体检验与分离等模型;教学过程中基于证据进行推理、基于模型进行认知,从而提升学生的理性思维,发展学生的核心素养。     

凸显“本质联系证据推理”的离子键与共价键教学

针对离子键与共价键在教学中存在本质分离、联系割裂和忽视“证据推理”素养发展目标的问题,依据元素周期律中金属性和非金属性的递变规律进行推理,并寻找证据进行证实或证伪,以认清离子键与共价键的静电作用的成键本质和辩证统一的关系,发展学生证据推理的核心素养,提高学生的逻辑思维能力。     

发展学生化学学科核心素养离不开化学实验

化学实验是化学教学的重要组成部分,不仅具有教育教学功能,而且具有发展学生化学学科核心素养的功能。从认识层面、实践层面和价值追求层面来看,化学实验在发展学生科学本质观、科学实践观和科学价值观方面均发挥着不可替代的功能。教师可以利用化学实验史实呈现真实的科学发现过程,发展学生的科学本质观;可以通过引导学生对化学实验现象的观察和基于实验事实证据的推理发展学生“宏观辨识与微观探析”“证据推理和模型认知”素养;可以通过开展化学实验探究,引导学生拓宽认识视角和认识思路,发展学生“科学探究与创新意识”素养;可以通过化学实验评价发展学生的“科学态度和社会责任”素养。     

HPLC of basic drugs using non‐aqueous ionic eluents: evaluation of a 3 μm strong cation‐exchange material

HPLC columns packed with 3 μm particle size HPLC Technology Techsphere SCX (propylsulfonic acid‐modified) silica offer considerable advantages over 5 μm SCX packings in the analysis of basic drugs using 100% methanol eluents containing an ionic modifier such as ammonium perchlorate. The basic drugs studied included clozapine and norclozapine, olanzapine, quinine and quinidine, and amitriptyline, nortriptyline, imipramine and desipramine. The 3 μm column was not only more efficient for a given column length compared with 5 μm materials, but also elution times were less, a phenomenon observed in reversed‐phase systems. The high efficiencies and excellent peak shapes obtained with the 3 μm SCX‐modified packing together with the relatively low back‐pressures attained show that such materials deserve serious consideration by laboratories involved in the analysis of basic drugs. Manufacturers should offer such packings as a matter of routine. Alternative ionic modifiers such as ammonium acetate are available for use with mass spectrometric detection if required. Copyright © 2009 John Wiley & Sons, Ltd.     

Designing syntheses of cellulose and starch derivatives with basic or cationic N‐functions: part I—cellulose derivatives

The use of cellulose and starch derivatives that bear amino or quaternary ammonium moieties is steadily increasing, and the applications in industry are continuing to grow. These promising products are routinely used in cosmetic and paper‐making industries. This article provides an overview of strategies available to chemists for designing the syntheses of such compounds. The review provides a brief historical perspective on synthesis and describes recent developments that have enabled chemists to enhance their synthesis productivity. However, the graft polymerization techniques are far from the scope of this paper and will be noted in a few words only. In addition to the structural and synthetic aspects, applications of these derivatives are discussed in brief. We have divided this article in two parts mainly because of the vastness of the subject and limited space available. The first part of which reviews the advances in the synthesis of basic and cationic cellulose derivatives having amino or quaternary ammonium moieties and the second part of which considers starch ones. Copyright © 2015 John Wiley & Sons, Ltd.     

Synthesis of Polycaprolactone Using Free/Supported Enzymatic and Non‐Enzymatic Catalysts

Summary: Polymerization of caprolactone using lipases from Candida antarctica B, Rhizomucor meihei, Candida rugosa, and Pseudomonas fluorescens is highly effective, with 97% conversion into polycaprolactone. Poly(propylene)‐supported Candida rugosa lipase achieves higher conversion values (85–92%) than free lipase (75%). Acidic and basic non‐conventional catalysis with butanol yields 50–85% conversion. Simple UV/visible techniques gave the same results for measuring conversion than other studies. Applications are opened for the non‐conventional catalysts.

Mechanism of the polymerization of caprolactone polymerization using a basic catalyst.     

“强基计划”背景下高分子化学教学改革与探索*

为了服务国家重大战略需求,加强基础学科拔尖创新人才选拔培养,我校于2020年开展基础学科招生改革试点工作,即“强基计划”。“强基计划”中对化学专业采取的培养新举措,旨在培养具有扎实基础化学知识、熟练化学技能和胸怀空天报国理想的化学和应用化学专业本科生。这也将为我校航空航天特色高分子材料和技术的发展起到强有力的支撑和保障作用。针对“强基计划”背景下高分子化学课程的改革进行了探讨,采用以培养能力为主线、以启发式和拓展式教育为主的教学方法,将课堂教学、实验教学与课程设计相结合,有力地促进了教学质量的提高。     

Signaling Pathways of Immobilized FGF‐2 on Silicon‐Substituted Hydroxyapatite

Therapeutic strategies for bone regeneration involve the selection of suitable biomaterials, growth factors, and cell types to mimic the cellular microenvironment where molecular and mechanical signals control the reconstruction of bone tissue. The immobilization of basic fibroblast growth factor (FGF‐2) on powdered silicon‐substituted hydroxyapatite (Si‐HA) allows to prepare a biofunctional biomaterial able to interact with bone cells in a very specific way. The biological activity of FGF‐2/Si‐HA, evaluated in Saos‐2 osteoblasts and MC3T3‐E1 preosteoblasts through the PLCγ and MAPK/ERK signal transduction pathways, shows that FGF‐2 immobilized on Si‐HA provides the right signals to cells stimulating crucial intracellular mechanisms of osteoblast proliferation and differentiation.

     

Structural Investigation of Mixed Nitrided Galloaluminophosphates “AlGaPON” by EELS, XAS, and XPS Spectroscopies

Amorphous nitrided galloaluminophosphates “AlGaPON” catalysts with nitrogen contents varying from 0 to 23.3 wt% N were obtained by nitriding an Al_0.5Ga_0.5PO₄ precursor under ammonia flow at 750°C in a tubular furnace. The structural changes induced by this treatment were investigated by electron energy loss spectroscopy (EELS), X-ray absorption spectroscopy (XAS), and X-ray photoelecton spectroscopy (XPS). XANES and XPS results indicate that the first-coordination spheres of P, Ga, and Al atoms are modified by nitridation. In particular, the comparison of the P XANES spectra recorded on “AlGaPON” and on a PON phosphorus oxynitride (reference of mixed PO₂N₂ tetrahedra) reveals that mainly PO₂N₂ tetrahedra are present in highly nitrided samples. Moreover, the replacement of oxygen by nitrogen probably concerned P-O-Ga bonds rather than P-O-Al. EELS investigation reveals that the precursor is homogeneous at the used probe scale, but indicates that nitridation is accompanied by a loss of homogeneity of the material.     

Base‐deactivated and alkaline‐resistant chromatographic stationary phase based on functionalized polymethylsilsesquioxane microspheres

Vinyl, chloropropyl, and mercaptopropyl functionalized particles were prepared by a two‐step acidic/alkaline catalyzed co‐hydrolysis/condensation of methyltrimethoxysilane with a different silane precursor that carries chemically reactive functional group including vinyl, chloropropyl, and mercaptopropyl, respectively. The morphology, pore structure, and functional groups of the synthesized packings were studied by SEM, nitrogen adsorption‐desorption measurements, and solid‐state ¹³C ²⁹Si NMR spectroscopy, respectively. The particles show ordered sphere, narrow particle size distribution, and mesoporous structure. The carbon contents of the microspheres are in the range of 17–19%, comparable to those of octadecyl‐bonded silica packings. The three‐kind of microspheres were directly used as packing materials for high‐performance liquid chromatography without size classification. The chromatographic performance of the columns was evaluated and compared with a commercially available C₁₈ phase. The results revealed that these columns possess typical reversed‐phase chromatographic properties with increased hydrophobicity than polymethylsilsesquioxane and symmetric peaks for basic compounds. They were applied to the simultaneous separation of combination bendazol hydrochlorothiazide capsules containing polar and basic drugs with peaks identified by tandem with mass spectrometry. In general, a novel method is provided for the synthesis of different methyltrimethoxysilane‐derived microspheres for high‐performance liquid chromatography, which are advantageous for separating basic compounds.     

Epoxide‐derived mixed‐mode chromatographic stationary phases for separation of active substances in fixed‐dose combination drugs

A method for the preparation of novel mixed‐mode reversed‐phase/strong cation exchange stationary phase for the separation of fixed‐dose combination drugs has been developed. An epoxysilane bonded silica prepared by vapor phase deposition was used as a starting material to produce diol, octadecyl, sulfonate, and mixed octadecyl/sulfonate groups bonded silica phases. The chemical structure and surface coverage of the functional groups on these synthesized phases were confirmed by fourier‐transform infrared and solid‐state ¹³C NMR spectroscopy and elemental analysis. Alkylbenzene homologs, basic drugs, nucleobases and alkylaniline homologs were used as probes to demonstrate the reversed‐phase, ion exchange, hydrophilic interaction and mixed‐mode retention behaviors of these stationary phases. The octadecyl/sulfonate bonded silica exhibits pronounced mixed‐mode retention behavior and superior retentivity and selectivity for alkylaniline homologs. The mixed‐mode retention is affected by either ionic or solvent strength in the mobile phase, permiting optimization of a separation by fine tuning these parameters. The mixed‐mode stationary phase was applied to separate two fixed‐dose combination drugs: compound reserpine tablets and compound methoxyphenamine capsules. The results show that simultaneous separation of multiple substances in the compound dosage can be achieved on the mixed‐mode phase, which makes multi‐cycles of analysis for multiple components obsolete.