分析化学实验MOOC平台建设

In light of the objectives and teaching status of analytical chemistry laboratories, the massive open online course (MOOC) platform for analytical chemistry laboratories is developed and modified based on trial and feedback from students. An outlook is given on the MOOC platform for laboratory courses.     

“三因一选”模式——新时代大学化学实验教学改革探索

It is a powerful tool of talent development to reinforce the nation's power. For educating comprehensive talents, teaching of chemistry laboratory for undergraduate is of great significance. In the light of college chemistry experiment, we propose a teaching mode named "3 factors & 1 choice", that is teaching in accordance with majors, teaching in accordance with local condition, teaching in accordance with general trends, and optional experiments. It aims to combine the characteristics of each major with specific experiments, to enhance students' conscious activity, and to strengthen students' creative thought and practical innovation ability.     

高校无机化学实验室资源合理配置的探索与实践

实验教学是高校人才培养、科学研究和学科建设的重要环节,实验室作为实验教学的场所,资源优化配置至关重要。本文分析了天津大学无机化学实验室在资源配置上存在的问题和相关的解决措施,如开设化学类通识实验课程,使授课学生不局限于化学类;使用研究生助教和学生志愿者,减轻实验员工作量;开放实验室设备资源;举办化学化工技能大赛等。以期为其他高校实验室的资源合理配置提供借鉴和参考。     

A Colorful Investigation of a Diprotic Acid: A General Chemistry Laboratory Exercise

A general chemistry laboratory experiment that can be completed in a single laboratory period is described that familiarizes students with the acid—base chemistry of a diprotic acid and with the use of visible spectroscopy to determine species concentrations. This experiment is a modified version of a previously described laboratory exercise developed for an upper-division quantitative analysis course. Students work in teams and as a class to generate different ionization states of various highly absorbing dyes. Both spectroscopic and potentiometric (pH) data is collected using LabWorks II stations, but other inexpensive pH meters and visible spectrometers (e.g., Spec 20s) are suitable. A spreadsheet template is used to determine the percent composition of various ionization states of a diprotic acid and to determine the pK_a values. Besides introducing students to fundamental tools and key chemical concepts, this laboratory is also inexpensive to operate and utilizes nontoxic, colorful solutions.     

Merging two traditional methods: the Hartree–Fock and the Heitler–London and adding density functional correlation corrections

The variational combination of the Hartree– Fock (HF) with the Heitler–London (HL) methods, yielding the Hartree–Fock–Heitler–London (HF–HL) method is analyzed for diatomic hydrides and homonuclear molecules of the first and second row atoms. This recent quantum chemistry development is considered in the light of the continuous evolution of hypotheses and corresponding verifications occurring in quantum chemistry. The correlation energy correction needed in HF and HL computations is reduced in the HF–HL method to its dynamic component, since the non-dynamical correlation is accounted by explicitly considering near degeneracy and state crossing. The dynamical correlation is computed either (1) via expansion with multi-configuration of HF and HL functions or (2) including ionic HL structures, yielding a large fraction of the molecular extra correlation energy or (3) using the Coulomb hole density functional. With the latter the computed total and binding energies for all internuclear separations are in excellent agreement with laboratory data. Contribution to the Serafin Fraga Memorial Issue.     

浅谈制药工程专业有机化学实验教学的心得和体会——以三苯甲醇的制备和重结晶实验为例

有机化学实验是制药工程专业的一门必修课,旨在训练学生有机合成基本实验技能。本文以三苯甲醇的制备和重结晶实验为例,讲述了笔者在多年教学中获得的一点感悟和经验:1)将实验步骤分解成片断讲解可以使学生更好地理解和记忆实验过程和操作目的;2)重要的基本操作应反复练习,即"学习、复习、提高",通过三次重复练习来实现巩固和熟练掌握该操作的目的。     

The Big Freeze: Water and the Scientific Process

In recent years there has been increasing movement toward laboratory exercises that are inquiry-based, requiring students to assume more active roles in the learning process. A laboratory experiment was developed in this light, framed around a simple question, “Which freezes faster, hot water or cold water?” The experiment was used at the beginning of the general chemistry year-long course sequence and served as an introduction to the scientific process. Students were each asked to develop a hypothesis and then design a simple experiment to determine which freezes faster, hot water or cold water, using small cold baths to freeze the water. A strength of this experiment is that students not only design and perform the experiments, but at the end they evaluate each other’s methods.     

Unexpected photolytic decomposition of alkyl azides under mild conditions

Alkyl azides have been found to undergo an unexpectedly facile photodecomposition under mild conditions (laboratory light) and the reaction gives rise to small amounts of aldehydes and monoacyl aminal rearrangement products that can dramatically impact on the uses of azides in chemistry, biology and medicine.     

Teaching Chemometrics with a Bioprocess: Analytical Methods Comparison Using Bivariate Linear Regression

We present an advanced analytical chemistry laboratory experiment involving chemometrics. Students perform a comparison of two analytical methods by checking several analyte concentrations within a certain range by using least-squares linear regression. They obtain statistical information such as the presence of constant and proportional biases. The exercise is based on the determination of glucose levels using two colorimetric methods (enzymatic and Somogyi—Nelson) in a very simple batch system formed by an infusion of tea, glucose, and a combination of a yeast (Schizosacaromyces pombe) and a bacteria (Acetobacter xylimun), usually named Kombucha. Several samples are collected during a week of laboratory work, and measurements are performed in a subsequent four-hour laboratory class. Although commercial computer software exists for a variety of statistical applications, specific programs for the application of statistics to analytical chemistry are not prevalent. In order to solve this particular problem, a Matlab 5.3 routine is presented.     

Incorporation of Phytoremediation Strategies into the Introductory Chemistry Laboratory

An undergraduate laboratory exercise appropriate for introductory chemistry courses at the high school or college level is presented. The objective of the laboratory is to introduce the idea that plants can be used to remove contaminants from the environment–a process called phytoremediation. This laboratory connects the disciplines of chemistry and biology while enabling students to learn the skills of measurement, titration, calculation of molarity of an unknown solution, graphing, and interpretation of data.     

无机化学实验成绩评价标准与考核方式初探

根据我院实际情况,对无机化学实验考核方式进行了探讨,将实验教学考核成绩分成平时成绩、阶段成绩和结课成绩三个部分,建立了注重实验结果的同时更注重实验过程及实验技能的考核体系。     

Total Lipid Extraction of Food Using d-Limonene as an Alternative to n-Hexane

A useful and green method for the extraction of fats and oils with a new procedure combining Soxhlet extraction and Clevenger distillation using d-limonene (bio-solvent) as a substitute for n-hexane (petroleum solvent) is reported. This method using green solvent is a laboratory exercise which easily teaches fundamental green analytical chemical lessons and successfully incorporates green “analytical chemistry” into the teaching and the research laboratory to both developed and developing nations.     

有机分子荧光光谱中的AIE和ACQ现象

基础化学实验室主要开设基础类、大面积通识课程,开课对象以非化学专业、低年级本科生为主。基础化学实验室在实践教学活动过程中往往涉及危险化学试剂以及高温、高压等危险操作,加之新形势下大类招生不断扩大,基础类课程教学任务与日俱增,基础化学实验室的安全运行管理面临的挑战更加严峻。以西安交通大学基础化学实验室为例,介绍了我校基础化学实验室现状及在安全运行与管理方面存在的问题和解决对策,为同类型化学实验室的安全运行与管理提供借鉴与参考。     

Light-to-chemical energy conversion in lamellar solids and thin films

Photocatalytic water splitting by visible light is one of the most difficult and persistent challenges in chemistry. This Forum Article reviews progress in this field, focusing on efforts made in our laboratory to control electron- and energy-transfer reactions, and catalytic hydrogen and oxygen evolution, in lamellar solids and thin films.     

“线上线下-虚实结合”在有机化学实验教学中的应用探索——以正溴丁烷的制备实验为例

In response to the impact of the Covid-19 epidemic on organic chemistry laboratory teaching, this article analyzes and discusses the current limitation of traditional organic chemistry laboratory teaching. Taking the "preparation of n-bromobutane" as an example, a new "online-offline and virtual-actual combination" teaching mode with the combination of "Tencent Meeting, MLabs, laboratory and WeChat group" is introduced. The practice of the new mode of teaching includes the following steps: pre-class online guiding by teacher, student preview and practice based on the virtual simulation platform, students and teacher discussion and operation in laboratory, and post-classcomprehensive assessment and Q&A", and good teaching effects have been received. It is significant in cultivating and improving the independent innovation and practical ability, and provides reference for the organic chemistry laboratory teaching reform and also lays a foundation for the construction of "outstanding course" of organic chemistry.     

Analytical advances to study the air – water interfacial chemistry in the atmosphere

Formation of aqueous secondary organic aerosol (aqSOA) at the air – liquid interface recently has attracted a lot of attention in atmospheric chemistry. The discrepancies in mass distributions, aerosol oxidative capacity, liquid water content, hygroscopic growth of aerosols, and formation of clouds and fogs suggest that interfacial chemistry play a more important role than previously deemed. However, detailed mechanisms at the air–water interface remain unclear owing to the lack of comprehensive understanding that underpins complicated interfacial phenomena, which are not easily measurable from field campaigns, laboratory measurements, or computational simulations. This review highlights relevant and recent technical advancement employed to study aqSOA encompassing spectroscopy and mass spectrometry. The current knowledge on the aqSOA processes is digested with an emphasis on recent research of interfacial aqSOA formation including laboratory studies and model simulations. Finally, future directions of the interfacial chemistry are recommended for field and laboratory studies as well as theoretical efforts to resolve interfacial challenges in atmospheric chemistry.     

基于微课的翻转课堂教学模式在分析化学实验教学中的探索

分析化学实验是大学化学实验的重要内容,是分析化学课程学习中不可缺少的组成部分。为了提高分析化学实验教学质量,提升学生动手能力、分析问题和解决问题的能力以及创新能力,解决传统教学模式存在的主要问题,对分析化学实验教学模式进行了改革探索。将以微课为基础的翻转课堂教学模式引入到分析化学实验中,激发学生的实验热情,提高学生综合实验技能,巩固基础理论知识,培养了科学研究思维,真正实现创新性人才培养目标。     

Over one century after discovery: pyrylium salt chemistry emerging as a powerful approach for the construction of complex macrocycles and metallo-supramolecules

Over one century after its discovery, pyrylium salt chemistry has been extensively applied in preparing light emitters, photocatalysts, and sensitizers. In most of these studies, pyrylium salts acted as versatile precursors for the preparation of small molecules (such as furan, pyridines, phosphines, pyridinium salts, thiopyryliums and betaine dyes) and poly(pyridinium salt)s. In recent decades, pyrylium salt chemistry has emerged as a powerful approach for constructing complex macrocycles and metallo-supramolecules. In this perspective, we attempt to summarize the representative efforts of synthesizing and self-assembling large, complex architectures using pyrylium salt chemistry. We believe that this perspective not only highlights the recent achievements in pyrylium salt chemistry, but also inspires us to revisit this chemistry to design and construct macrocycles and metallo-supramolecules with increasing complexity and desired function.

This perspective summarizes the representative efforts of synthesizing and self-assembling large, complex architectures using pyrylium salt chemistry.     

化学分析实验课程全英文教学方法研究

化学分析实验是分析化学教学的重要组成内容,是实践分析化学"量"的概念的重要途径。本文探讨了国际化合作办学背景下化学分析实验课程的全英文教学模式与方法,总结了化学分析实验(全英)课程建设过程的经验与不足,展望了化学分析实验全英文教学的前景。     

化学类专业实验教学改革的进展、趋势与重点

综述了过去近20年我国化学类专业实验教学改革的主要内容和取得的主要成绩,分析了当前实验教学中存在的主要问题和挑战,采用目标导向的方式,对实验教学目标、教学内容、教学模式、管理模式的改革趋势进行了分析,提出了改革的要求和思路.对今后的实验教学改革和建设具有一定的指导意义.