In Chinese literature on polymer chemistry and photo-chemistry, "quench" and "quencher" are both expressed in two different terms. And this has been bringing trouble to teaching and academic exchanges. To solve this problem, an analysis and textual research were made on these words from both linguistics and chemistry perspectives. A solid conclusion is led, and the right word for quench and quencher in Chinese are given. Also, a suggestion is made that, it should be adopted in the relevant books and specifications.

Five typical specious questions in polymer chemistry were discussed, including "the criterion of the spontaneity of a polymerization is △G < 0", "the activities of the two kind of active centers in an ideal copolymerization are the same", "ferrocenylmethyl acrylate (FMA) has a higher propagation rate constant of homopolymerization than 2-ferrocenylethyl acrylate (FEA)", "Methyl 3-(4-methylphenyl)-2-propenoate, or Methyl 4-methylcinnamate, can be homopolymerized into high polymer" and "α-cyanoacrylate cannot be free radically homopolymerized". Through raising and answering these questions, the students were encouraged to think, to doubt, to question, to explore, to acquire, and to understand under the teacher's inspiration and guidance. This helps to train the critical thinking skills, the problem conversion ability and the literature consulting awareness, to build the awareness and abilities of problem finding and problem raising, and to develop the ability to analyze and solve problems, in addition to acquire the right knowledge.

A variety of domestic and international organic chemistry textbooks hold the standpoint that the two resonance structures of benzene are Kekulé structures. By introducing the research history of benzene structures and the structural characteristics of Kekulé's benzene, we propose that the above standpoint should be reconsidered. We also suggest that the two resonance structures should be named as "Pauling's structure" or "Pauling benzene".

A teaching experiment for determining copper(Ⅱ) ions in copper-containing sewage by UV-Vis spectrophotometry is designed. The experiment is performed based on the Fenton reaction principle, where the presence of copper(Ⅱ) ions in the assay solution catalyzes the decomposition of hydrogen peroxide to produce hydroxyl radicals. The latter oxidizes the colorless 3, 3', 5, 5'-tetramethylbenzidine (TMB) in the solution to the yellow TMB²⁺, which can be used for quantitative analysis copper(Ⅱ) ions in copper-containing sewage by measuring the absorbance of TMB²⁺ at 452 nm. With easy operation, short measurement time, excellent stability, eco-friendliness, this experiment conforms to the basic requirements of undergraduate laboratory teaching.

In order to implement President Xi's speech on the national conference of ideological and political work in universities, and build a collaborative education mode of ideological and political theory course in the same direction with all kinds of courses, the important practice about utilizing the classroom teaching to educate students has been investigated. In this paper, an example of instructional design about integrating the intellectual education and moral education in the introduction section of inorganic chemistry is discussed, including the setup of learning goal, the selection and presentation of teaching content and development of teaching activities.

Ion transference number is an important parameter of physical chemistry, and its measurement is the basic content in physical chemistry laboratory. Based on the measurement of ion transference number in "Basic Physical Chemistry Laboratory", combined with measurements of the electromotive force, a new experiment was designed for measuring the transference number of copper ion and sulfate ion in solution, and the ion transference numbers obtained are basically consistent with the values in the literature. We attempt to use the laboratory skills that college students already mastered in physical chemistry laboratory and integrate the knowledge of electrochemistry to design and explore a new method for measuring ion transference by the electromotive force method. The students' comprehensive ability can be improved to solve problems.

Although at first glance, the old reaction of B₂H₆ (diborane) with NH₃ seemed to be simple, it has been shown that the reaction was complex and had perplexed boron chemists for decades. The reaction was highly sensitive to the experimental conditions, and one or the mixture of the products, such as diammoniate of diborane (DADB, [NH₃BH₂NH₃][BH₄]), ammonia borane (AB, NH₃·BH₃), aminodiborane (ADB, NH₂B₂H₅), could be obtained. It was known that the asymmetrical cleavage of the double bridge bond of B₂H₆ produced the ionic product DADB, whereas symmetrical cleavage afforded the covalent product, AB. The different cleavage patterns of B₂H₆ under particular conditions attracted interest to study the key points of the selectivity including steric effect, inductive effect, solvent effect, and dielectric constant, but it is still not possible to predict the products of the reactions of B₂H₆ with Lewis base. B₂H₆ was present in THF as the THF·BH₃ adduct, and the products of the reactions of Lewis bases with THF·BH₃or B₂H₆ were of the same types. The formation mechanisms of AB and DADB were explored by an ingenious design using THF·BH₃ as a proxy for more reactive B₂H₆, and the reaction of THF·BH₃ with NH₃could be carried out under mild conditions. It was found that dihydrogen bonds played a critical role in the competing formation of AB and DADB. Both experimental and computational results demonstrated that dihydrogen bond was the dominant factor in the complex formation mechanism of ADB.

The disconnection approach is applied to teaching of polymer chemistry. The disconnection strategy for usual polymer synthesis problem is proposed, the rules are summarized, and the usual polymer synthesis problem is categorized. These approaches made it easier for the students to handle polymer synthesis problems, to learn the method and have the ability to learn. Accordingly, a new classification of polymerization reactions is suggested, which classifies polymerization reactions into three categories by occurring between functional groups, via opening of double bonds, and by opening of rings. It is also summarized that the disconnections in polymer synthesis are usually made between the units along the main chain, between the main chain and the side groups, between the main chain and the branches, and between the main chain and the end groups, and at the position of the functional groups or the heteroatoms.

Vincent Van Gogh is considered today as the greatest Dutch painter and loved by many people. Unfortunately, his paintings suffered degradation problems. This paper introduces the pigments used in Van Gogh's paintings and reveals the fading's secret based on chemical principles, the research of pigment chemistry also can help to choose the best strategy for the proper conservation of art masterpieces.

A series of innovative teaching practice are carried out from the aspects of thought updating, content optimizing, method improving, means updating, integration strengthening and penetration enhancing, under the guidance of the teaching thoughts of "student-centered, and focusing on the cultivation of students' interest and ability, especially the ability of sustainable development and innovation". The practice aims at the key points and difficult problems in the teaching and the weaknesses in the learning of polymer chemistry, based on the analysis of students' learning situation. Good teaching results and a series of innovative teaching accomplishment have been achieved, and the course has been constructed into a provincial first-class course.

Aromaticity is a key concept in organic chemistry. It dated back to Faraday's discovery of benzene in 1825 and Kekulé's famous alternating-double-bond structure of 1865, and is still evolving in recent years. At present, some examples of anti-Hückel's rule have been proposed gradually, including Möbius aromaticity rule and Baird's rule. In particular, scientists put forward new concepts of 3D aromaticity and global aromaticity. This review not only introduces the experimental and theoretical criteria of aromaticity, but also summarizes several new aromaticity systems through porphyrin nanoring, macrocyclic polyradical and polycyclic π-conjugated system. In addition, it covers the applications of aromaticity and briefly discussed recent progress on the concepts of aromaticity.

This paper analyzes and compares the structure of cubic diamond and hexagonal diamond, and emphasizes the structural differences between cubic crystal and hexagonal crystal. The template of tetrahedral four coordination and tetrahedral four coordination coupling with linear two coordination crystal structure is established based on the diamond structure, and employed to analyze the material with similar structure.

A new experiment of the photoluminescence spectrum of organic molecules was introduced to undergraduate teaching. The emission behaviors of different aggregation with perylene and 1, 1, 2, 3, 4, 5-hexaphenylsilole (HPS) as typical luminophores were measured so as to observe the different phenomena of aggregation-caused quenching (ACQ) and aggregation-induced emission (AIE). The crystal structures characteristics of the above molecules could be obtained by the use of the Cambridge Crystallographic Data Centre (CCDC). The causes of the phenomena of AIE and ACQ were analyzed from the aspects of structures of molecular crystals. Therefore, the intrinsic relations between photoluminescence mechanism and molecular states were discussed on this basis. In this paper, the design, contents and conclusions of the photoluminescence experiment were elaborated in detail. Combining with the teaching process, the teaching effects were discussed for broadening the undergraduates' horizons as well as improving their cognitive abilities and scientific research qualities.

The paper designed a chemical experiment based on carbon dots which own excellent fluorescence properties. Students need to synthesize blue and green carbon dots through "bottom-up" method, search the relationship between fluorescence excitation spectra and fluorescence emission spectra, measure the fluorescence quantum yield by comparing with a reference fluorophore, explore the changes of fluorescence spectra at different concentrations and pH, and apply the carbon dots to anti-counterfeit materials. All these will make students have a good command of fluorescence principle, such as fluorescence excitation spectrum, fluorescence emission spectrum, fluorescence quantum yield, Stokes shift and the factors that influence fluorescence. We also encourage students to apply the knowledge they have learned to their daily life.

Rearrangement reaction is one of the most important contents in the course of college organic chemistry. These reactions can be found in many chapters, and might be easily forgotten by students in the learning process. Thus, it is of great importance to carry out inductive teaching for relevant contents. Herein, we summarize and analyze in depth the rearrangement reactions involved in college organic chemistry. These analyses at the mechanism level are beneficial for understanding and memorizing of the reactions. In addition, the application of inductive analysis of rearrangement reactions in teaching practice through several cases is also introduced. The results show that this teaching method played an important role in promoting the understanding and mastery of relevant knowledge. Similar method can also be applied to the teaching process toward other systematic knowledge.

Analytical chemistry laboratory is one of the basic courses for many majors in the universities. Since it starts in junior years, how to integrate ideological and political education elements into analytical chemistry laboratory has a great influence on building up the correct outlook on the world, life, values for the students, and it also has significant impact on cooperation education using the professional course and ideological and political course in the same direction. Using the complexometric titration experiment as an example, this paper introduces the excavation of ideological and political elements in Applied Chemistry major of Central South University, and constructs corresponding teaching cases, reflecting the teaching objectives and ideological and political education objectives of the course design.

After the discovery in the year 1886, Molisch's reaction used to be applied as a powerful tool to differentiate carbohydrates and glycosides qualitatively from other materials. A brief review is given herein on the discovery, reaction mechanism and application of Molisch's reaction. Perspectives are also given on the potential applications of Molisch's reaction.

A comprehensive chemistry experiment was introduced, which involved the extraction of active ingredients of natural products and the preparation of daily chemical products by saponification reaction. This experiment systematically and coherently combined the basic knowledge of university organic chemistry, basic laboratory skills and life to prepare flower soaps. Through the experiment, students' interests and understanding of the knowledge of organic chemistry will be stimulated. Meanwhile, their ability of innovation will be improved.

The pursuit of perfect blue pigments since the 20th century has led to new breakthroughs in the field of contemporary art and the development of new pigments. After two years of research on Cyanotype, we created a series of cyanotype works using different materials and fine-tuned processes. Cyanotype experiment was chosen into the chemistry laboratory course. It is a "Cyanotype adventure" that blends chemistry and art by holding an art exhibition to introduce cyanotype to the public.

In this paper, the organic chemistry experiment "cyclohexanol oxidation to cyclohexanone" was improved by two green oxidants: potassium bisulfate (Oxone) and trichloroisocyanuric acid (TCCA). A by-product was found in the oxidation with Oxone, and the structure of the by-product was determined by GC-MS. The contents of the target product and by-product under different conditions were studied. When TCCA was used as oxidant to prepare cyclohexanone from cyclohexanol, the higher pure target product was obtained (93%), which can be used to replace the original sodium dichromate oxidation of cyclohexanol to cyclohexanone. Through the introduction of the concept of green chemistry, the students can learn the importance of green chemistry in organic synthesis, and be stimulated the interest in scientific research. It is more important to guide students to pay attention to new discoveries in chemical experiments and to search for the causes or processes of new discoveries, and find out new solutions.

Chemical experiment courses are important basic curriculum offered by the universities and colleges involving science and technology, and they are also indispensable links for learning and understanding chemistry. Fully extracting ideological and political elements relevant to the chemical experimental courses and integrating them into course teachings can not only help undergraduates deeply understand the theoretical knowledge and activate the classroom atmosphere, but also stimulate their learning enthusiasm and cultivate their professional quality and social responsibility, achieving the goal of knowledge education and value guidance in higher education.

In physical chemistry, transition state theory is the key and difficult point of chemical kinetics. In this work, three methods of computational chemistry are used to search for the reaction transition state, and the reaction rate constants at different temperatures are presented. This enables students to have a more intuitive and clear understanding of transition state and reaction mechanism, and helps them learn chemical kinetics more effectively.

The hcp and ccp are the two main structures that most metals adopt. The tetrahedral holes and octahedral holes in these structures are commonly difficult for students to grasp. In this paper, we focus on the arrangement of the holes in the close-packed structures. This is also very helpful in learning ionic crystals.

In response to the COVID-19 pneumonia epidemic, large-scale online final examinations become a new research focus of teaching research. Taking the course "inorganic chemistry and chemical analysis" as an example, this paper introduces the online examination's design, preparation, implementation and the feedback of the students. It summarizes the experience and gives the new pattern of examinations in order to provide references for the large-scale online examinations of universities.

A scientific and impartial evaluation method was made according to the characteristics of designing experiments, which examine the students' ability of experimental design ability, experimental operation ability, and ability to analyze and solve problems. The designed experimental assessment can inspire the students' experimental enthusiasm and go-aheadism, enhance their ability to apply knowledge comprehensively to innovate practice and promote their innovative consciousness and practice skills.

"Determination of calcium content in dolomite" is one of the important experiments in college analytical chemistry laboratory. During the experiment, students found that the initial redox reaction rates are significantly different between the calibration experiment of potassium permanganate solution by sodium oxalate standard solution and the titration experiment of calcium oxalate formed from dolomite by the calibrated potassium permanganate solution. Based on these experimental phenomena and combined with chemistry theory mastered by students, some conjectures and explanations were put forward. After that, we guided students to design experiments to explore and verify them. Through these experiments, it can not only answer the students' doubts, but also train and improve their ability to analyze and solve problems, and thus stimulating students' interest in chemical experiment learning.

Strengthening the construction of course ideology and politics is very important for college education. It is an inevitable trend and urgent need for the implementation of the fundamental task of establishing morality in college education. This article introduces the overall thinking and practical exploration of curriculum ideological and political development in analytical chemistry. According to the characteristics of analytical chemistry, we select appropriate knowledge points to connect to the relevant content of ideological and political courses during the teaching of analytical chemistry. Through constructing an ideological and political case database, digging out the ideological and political elements in the frontiers of science, and carrying out flexible and diverse full coverage ideological and political teaching, the professional knowledge is effectively integrated with ideological and political education. In such a way, the content of ideological and political education can naturally penetrate into classroom teaching, and further cultivate and deepen students' awareness of home country feelings, cultural self-confidence, scientific spirit, civic awareness, and sound personality.

Strengthening laboratory teaching is an important way to cultivate students' scientific literacy and comprehensive innovation ability. Taking physical chemistry laboratory as an example, the teaching reform and practice were carried out to solve the problems of writing experimental report. A research paper type experimental report writing format was adopted for undergraduate course teaching, which is helpful for students to understand the whole picture of the experiment, put forward questions, analyze questions and summarize the experiment. The cultivation of students' scientific literacy and comprehensive innovation ability has been achieved throughout each part of the experimental report, which is unified with the actual teaching link. It gives the full play to the synergetic advantages of teacher-led and student-subject, stimulates students' learning enthusiasm and subjective initiative, and is conducive to the cultivation of high-quality talents with comprehensive development of characteristics including morality, intelligence, physique, aesthetics and labor.

The electronic nose is a high-tech product developed to simulate the olfactory organs of animals. As the core component of the electronic nose, the gas sensor converts information such as composition and concentration into electrical signal by reacting with the gas to be measured. The sensors can realize the fast, sensitive and real-time detection of harmful gases in the environment. This article introduces the basic principles and application fields of semiconductor, electrochemical, and infrared gas sensors, focusing on the research progress of gas sensors in recent years, and prospects for their future development.

In physical chemistry, the model of solvent cage is used to describe the relationship between reactant and solvent. In this model, the reactant molecule is surrounded by the cage constructed with solvent molecules. The solvent cage is flexible, and its size and shape are determined by the central reactant molecule. The encounter, collision and reaction between reactant molecules proceed in solvent cages. With the advancement of synthetic techniques, molecular cages, which are constructed by covalent and coordination bonds, are developed. Relative to the solvent cages connected with van der Waals force, molecular cages show much higher rigidity, thus, their effects on the reactions is expected to be more remarkable. Different from traditional catalysts that participate the reaction through the binding with reactants or intermediates, molecular cages could affect the reaction through a physical manner. By enriching reactants, altering the configuration of reactants, changing the structure of intermediates and limiting the growth of products, molecular cages could exert a profound influence on the rate and selectivity of the reaction. The research on this field is significant for the elucidation of reaction mechanism and the modulation of reaction proceeding.

Inductive and deductive methods are important for organic chemistry learning. The effects of hydroxyl and methoxy groups on carboxylic acid acidity in several systems are analyzed. The influence of hydrogen bonding on carboxylic acid acidity varies in different systems.

The teaching of the modern spectral analysis course focuses on the cultivation of the comprehensive quality and ability of postgraduate students, and constantly explores how to carry out the course construction and teaching reform to achieve the course objectives: (1) We keep pace with the times and constantly update the teaching contents to reflect the scientific and cutting-edge nature of the course. (2) We integrate the ideological and political elements into the course of the modern spectral analysis to help the guidance on moral values of the graduate students. (3) We constantly innovate our teaching methods and explore flipped class, project-based learning, using intelligent teaching tools to manage teaching progress and construct diversified assessment methods.

The experimental design of quantitative research on the absolute hardness of compounds in Hard and Soft Acid and Base (HSAB) rule using Gaussian software is introduced, which involves geometry optimization and high-level single point energy calculation. Through the experiment, students will grasp basic steps of using quantum chemistry to calculate the absolute hardness, deepen their understanding of the theory of HSAB, and lay the foundation for future research work.

Based upon the method of making recycled paper and the knowledge of natural pigments, this popular science experiment proposed an approach for making recycled paper dyed with vegetable pigment. This popular science experiment exhibited scientific, intriguing, brief and high operability. Moreover, we also creatively designed some interesting handmade works including pulp paintings, coasters, and origami, using dyeing paper and dyeing pulp. This experiment would provide a useful practice of chemical sustainable development, which helps the public better understand the chemical principle of recycled paper making and the extraction method of natural pigments.

Nuclear Magnetic Resonance (NMR) is a common method to analyze the structure of organic compounds, and it is also one of the important contents in the course of organic spectrum analysis. This paper introduces the idea of ¹H NMR analysis, combining theory with three examples of scientific research practice, using ¹H NMR to identify the structure of isomers in organic synthetic products, and determine the proportion of isomers by the integral area of peak group, in order to cultivate students' scientific literacy, stimulate students' interest in learning and improving the ability of spectrum analysis.

The integration of professional courses and ideological and political education is the fundamental task of moral education in colleges and universities. In this study, based on the character and teaching objectives of structural chemistry, possible methods for ideological and political education in the course are explored for cultivating students' philosophy and science, national pride and self-confidence in order to realize the organic unity of knowledge imparting and value leading.

This paper introduces the description in application of the theory of valence shell electron pair repulsion in textbooks at home and abroad. The main methods for determining the number of valence-layer electrons of the central atom are compared and analyzed, including the methods based on Lewis electronic determination method, the group number of the central atom and the number of electrons provided by the coordination atom, the valence electron number of the center atom in the ground state and the unpaired electron number of the coordination atom, and the total number of valence electrons of related atoms in the ground state and octet rule of coordination atoms. The theoretical basis and the physical meaning of the different methods are expounded. The main aim is to develop a consensus on this fundamental chemical theory to make it easy for the students to understand and master.

To improve comprehensiveness, innovation and exploratory of chemistry experiments for teaching, an experiment "preparation of maltose syrup by starch catalytic hydrolysis" was designed. The amylase was prepared and applied as catalyst in the starch hydrolysis process. The reaction had enzyme-catalyzed characteristics, with optimal catalytic temperature 55 ℃. The experiment design featured agriculture and forestry university discipline. Not only did it integrate theoretical teaching with practice to help cultivate the students' scientific spirit, but also was a profound ideological and political course.

Organic substance has been considered as organic compound, but the author does not think it's accurate. C₆₀ should belong to organic substance according to its structure and properties. Based on this fact, a common understanding will be formed: organic substances include both some carbonaceous elementary substances (e.g. C₆₀) and the vast majority of carbonaceous compounds.

In HF solution and HF-F^- solution, there are not only the dissociations of hydrofluoric acid but also the reactions between hydrogen fluoride and fluoride ion, so the equilibrium concentration of each component is the final product of two equilibria. Theoretically, the correct result can be obtained only if the two equilibria are considered simultaneously. However, much attention has been paid to the dissociation equilibrium of HF than to the HF-F^- association in teaching, as a result students are used to take the wrong calculation method when confronting such problems. In order to develop students' comprehensive abilities to deal with the calculations of complex systems, the simple and accurate formulas for calculating the ion concentrations in HF solution and HF-F^- solution are derived based on multi-equilibrium. By comparison, it is found that both equilibria must be considered in all cases, except that the concentration of HF solution is less than 1.91×10^-2 mol·L^-1 which can be approximately calculated as monobasic weak acid.

The kinetics of aspirin hydrolysis is the critical content of theoretical physical chemistry for both medical and pharmaceutical students. The experiment is usually conducted by monitoring aspirin's hydrolysis product (salicylic acid, SA) with a spectrophotometer after reaction with soluble Fe³⁺ salts. However, the kinetic measurement of aspirin hydrolysis has not been widely implemented in physical chemistry laboratory, because of the complicated procedures and the long testing period required to perform the reaction. In this work, the ultraviolet absorbance of SA at a wavelength of 296 nm has been employed to determine the kinetics of aspirin hydrolysis in a phosphate buffer (pH = 6.85). Compared with the traditional method, these improvements simplify the experimental procedures significantly, avoid the formation of liquid acidic wastes, and shorten the reaction time, thus, turn the hydrolysis of aspirin into a practical kinetic experiment for medical and pharmaceutical college students.

Combining the characteristics of chemistry practical teaching, this paper analyzes the problems existing in organic chemistry laboratory teaching and discusses how to apply PBL model to organic chemistry laboratory teaching. A new teaching model of "students-oriented, teacher-assisted" could be formed. At the same time, it explores the practical way of integrating course ideology and politics into organic chemistry laboratory. An emerging engineering education system with the concept of "cultivating people with morality" is formed by integrating ideological and political theories into discipline teaching. It is significant to strengthen ideological education and promote the comprehensive reformation of university organization model, discipline structure, talent training mechanism and teacher evaluation mechanism, systematically. A first-class excellent personnel training system will be built by integrating ideological and political elements into the whole process of new engineering ideas.

The feasibility of using the mole-ratio method for study of the formation and stability constant of sulfosalicylic acid-copper(Ⅱ) complex was explored. The experimental result revealed that the chelate-to-copper ratio was 1:1 at pH = 5, and its absolute stability constant was found to be lgK = 9.63, which was close to the value 9.52 from the handbook.

Acetal/ketal is a kind of important organic compounds, which is prepared by the nucleophilic addition reaction of aldehyde/ketone with alcohol or orthoformate. This reaction is also widely applied for protection of carbonyl group of aldehyde/ketone or ethylene glycol in organic synthesis. Therefore, synthesis of acetal/ketal attracts extensive concern. According to the different reaction systems, the research progress of acetal/ketal synthesis in recent years was reviewed in detail from three aspects, including acid catalysis, electrocatalysis and photocatalysis. It is expected that students could master this basic reactions and students' innovation ability will be developed by this review.

In order to solve the issues of traditional experimental teaching methods, the student-centered and blended learning mode was put forward by using instrumental analysis experiment as an example. The hierarchical teaching education mode was carried out to meet the needs of personalized training. Based on the online learning platform of Daxia School, online and offline linked learning activities can effectively stimulate the students' interest and initiative in learning. This guides students to internalize knowledge and cultivates their high-level thinking and comprehensive ability of analyzing and solving problems, benefiting the all-round development of the students.

Taking the School of Chemistry and Chemical Engineering, Liaoning Normal University as an example, under the background of the new era, thought was excavated to improve students' political accomplishment. Through the attention of experimental teaching content, students' sense of social responsibility was cultivated. At the same time, based on experimental teaching, students' rigorous and realistic scientific attitude were developed in the college. In addition, the stories of scientists were introduced into teaching for students to learn. Meanwhile, the research and design experiments were valued by teachers to strengthen students' innovative spirit and team consciousness. A preliminary exploration on the ideological and political education in physical chemistry experiments teaching was made in this paper, which would be a reference for the implementation of ideological and political education reform in University experiment teaching.

In the course of COVID-19 epidemic, online teaching exploration was carried out using Tencent Meeting software. The lecture notes were prepared before class in the form of audio courseware for live online teaching of two parallel classes with different schedule. This practice has shown that, such a teaching approach has the advantage of avoiding a slip of the tongue by the lecturer, performing effective teacher-student interactions, minimizing the loss by occasional student absence and enhancing the teaching quality. On the assumption that the epidemic situation becomes constant reality, this teaching practice has provided valuable guidance for a pluralistic teaching in combination of online and offline technique.

An undergraduate comprehensive electrochemical experiment was designed and developed. Based on the reversible cyclic voltammograms, the experiment was accomplished with a carbon nanotube modified electrode prepared by droplet coating. Using a Randles-Sevcik equation, the effective area of the electrode could be well calculated. Finally, the electrocatalytic detection of vitamin C was realized. The experiment described above partly filled up the shortage of teaching resources in cyclic voltammetry electrochemical technology for undergraduates. Thus, it shows a possibility of popularization among undergraduates.

Bread is the staff of life. However, few topics have been addressed on the chemical reactions related to food systematically and professionally in Chinese literatures. Such situation undoubtedly prevents the public to understand the essence of food through the phenomena, and results in the detachment of chemistry courses with livelihood. Based on this background, this manuscript focuses on the introduction of non-enzymatic Browning reactions, mainly caramel reaction, Maillard reaction and vitamin C oxidation, which contribute to the unique flavor and color of food. The molecular transformation in food related to medicine is also discussed from the perspective of chemistry, such as the conversion of iodine in table salt within the body, health adverse effects of trans-fatty acid, and the alcohol metabolism. It is hoped to set up a close connection between chemistry teaching and real life in order to bridge the gap between food science, medicine and other fields.

Rhodium and iridium are two rare elements of the platinum family, and they have very similar properties. In a third-person personification, their unique physical and chemical properties, such as boiling point, reflectivity, elastic modulus, catalytic activity, and chemical stability have been introduced by designing a game of challenges. Additionally, the properties of their oxides and halides are also included, especially their applications in electroplating, automobile tail gas catalytic converters, thermocouple manufacturing.

Nanozymes is a kind of nanomaterial with natural enzyme activity. Compared with natural enzymes, nanozymes have the advantages of simple preparation, low cost, high stability, and easy storage. Since Academician Yan Xiyun, a Chinese scientist, first discovered that Fe₃O₄ nanoparticles had peroxidase-like activity in 2007, the research on nanozymes has been rising rapidly. Nanozymes can simulate natural enzymes to achieve catalytic reactions in the physiological environment or in vivo, improve the tumor microenvironment, and achieve tumor treatment by generating reactive oxygen species.

This paper introduced the practices we have tried in teaching analytical chemistry classical contents to guide undergraduates to understand the frontier fields and innovative achievements of analytical chemistry, inspire their innovation thinking and cultivate their innovation ability. It is expounded that the classical contents of analytical chemistry are the source of cultivating the innovative ability of undergraduates. And the importance of mastering and in-depth understanding of the classical content of analytical chemistry for cultivating the innovation ability of undergraduates was also illuminated.

This article analyzed the pros and cons of the online examination of organic chemistry. During the spring semester of 2020, the teaching team carefully designed test papers and test methods to control the difficulty of test, thereby reducing the possibility of cheating, and successfully completing the online test. This article will provide a reference for the future online examination of organic chemistry courses.

The nomenclature of organic compounds is an important component in the teaching of organic chemistry, in which nitrogenous compounds occupy a considerable proportion. In this paper, the nomenclature of nitrogenous compounds based on "Nomenclature of Organic Compounds-2017" is explained to assist teachers and students master the new version of organic compounds nomenclature in the teaching and learning of organic chemistry, and realize the rapid transition of the nomenclature rules.

In response to the 2019-novel coronavirus pneumonia epidemic, teachers of the Chemical Experiment Teaching Center of the University of Science and Technology of China are actively exploring effective online teaching methods through self-developed instrumental virtual simulation software and online interactive classroom to provide a good learning experience for students who are studying at home. After the students returning to school, offline experiments were carried out. Taking gas chromatography experiment as an example, this paper puts forward some practice and thinking in the process of online and offline teaching.

This paper takes the science popularization of chemistry as an example to discuss the connotation and development process of documentary, particularly chemistry documentary. From the aspects of content, form and characteristics, this paper analyzes several chemical popular science documentaries with good reputation and high quality. The material and spiritual values of chemical documentaries are summarized, the prospect of science popularization in China is prospected, and some simple suggestions for the development of chemical science documentaries in the future are put forward.

The Limit of Detection and Sensitivity of analytical methods are two basic parameters for evaluating analytical methods. The International Union of Pure and Applied Chemistry (IUPAC) clearly recommends their definitions. However, both of them are still somewhat confused in some textbooks and research papers of analytical chemistry. Here, the definitions of both Limit of Detection and Sensitivity are clearly presented and the influence factors on Limit of Detection and Sensitivity of modern analytical methods are discussed. Some strategies to improve the Limit of Detection and the Sensitivity are proposed.

Flipped classroom as a kind of teaching method advocating active learning, has been widely welcomed as an online-offline hybrid learning method. Flipped classroom mainly includes two sections including students' Online autonomous learning away from the classroom and interactive learning activities in classroom based on encouraging problem-solving and experiential learning. In this paper, flipped classroom teaching method and traditional teaching method were used to carry out inorganic and analytical chemistry course for freshmen majored in biology. Additionally, SPSS was used to analyze students' performance and satisfaction with flipped classroom teaching method. The results show that students are actively participated in the flipped classroom teaching, the overall performance has been significantly improved, and students' satisfaction with the flipped classroom teaching method is higher. Thus, the flipped classroom teaching method has certain advantages over the traditional teaching method.

Aiming at common problems of classes instructed in English, we propose a new design method by referencing the Bachman communicative language ability model, based on the author's practice and thinking in recent years. Active communication and feedback in class are the keys to effective teaching. In view of this, we should pay special attention to five elements in English-based class: professional knowledge, language knowledge, strategic ability, language environment and personal characteristics. Therefore, we need to redesign the teaching method and strategies from these five aspects. At the same time, teachers must realize that the two dimensions of professional knowledge and language ability should be mutually supportive. Our practice shows that the new mode can significantly improve the teaching quality and curriculum satisfaction by activating the classroom atmosphere, promoting positive motivation, timely feedback and active learning.

This paper introduces the teaching reform based on "supramolecular chemistry course" at Henan Polytechnic University. Based on "student-foremost class" teaching ideas, this teaching reform involves three aspects, teaching contents, teaching methods and unique experimental teaching. Thus, a new mode of "fifty-fifty class" of "supramolecular chemistry course" was constructed, which motivated students to take the challenging learning, fully trained the learning ability, integrating resource ability, and communication skills of students, and synchronously improved quality, ability, and knowledge level of the senior undergraduates. This teaching reform has achieved good teaching effects.

Talent training is the main responsibility of colleges and universities. Teaching and education accepted at the undergraduate stage is crucial to the cultivation of innovative talents. Experimental teaching is one of the important links to improve the innovative ability of undergraduates in scientific research and to cultivate practical personnel. This paper systematically introduces how to apply the four-step teaching pedagogy based on "supporting-pulling-leading-releasing" to the multi-level analytical chemistry experiment course teaching so as to train students' comprehensive experimental skills at discovering, analyzing and solving problems step by step, and thus cultivating students' innovative perception and ability. The final goal of teaching knowledge and skills as well as training innovative research quality is achieved.

In the inorganic chemistry experiment, "Preparation and Component Determination of Hexamine Cobalt Chloride (Ⅲ)", the yield of product is low, which impedes the implement of subsequent experiment and teaching. Based on basic principles of chemistry, the effects of the quantity and particle size of activated carbon catalyst and the amount of hydrochloric acid and water were investigated. The experimental results showed that with 0.2 g, 120 mesh activated carbon catalyst, acid solution of 1 mL HCl plus 25 mL hot H₂O, and 3 mL concentrated hydrochloric acid, the yield of hexamine cobalt chloride(Ⅲ) was up to 42.5%, the color(orange), purity and crystallinity of the product were significantly improved. Through the experiment, the ability of students to apply the basic principles of chemistry to solve problems was enhanced.

Vitamin B₁₂ research process contains rich ideological and political elements. Based on exploring the discovery of vitamin B₁₂, the mechanism of treatment of pernicious anemia, VB₁₂ structure determination, artificial synthesis and biosynthesis, five ideological and political elements were condensed in this article, such as promoting traditional Chinese medicine, benefiting mankind with science, teamwork, perseverance and innovative spirit. It is expected to bring beneficial enlightenment for the development of course ideological and political education in related professional courses.

During the outbreak of COVID-19, online teaching has become popular. Inorganic chemistry laboratory course was chosen as an example to explore the online teaching of practical courses. With the help of the virtual simulation platform and videos of experiments, the efficient online inorganic chemistry laboratory classroom was built based on Tencent Meeting, Rain Classroom and WeChat. Taking the experiment of "the synthesis of Cr(Ⅲ) complexes and the determination of splitting energy" as an example to introduce the teaching process.

(-)-Menthone has been prepared by oxidation of (-)-menthol with sodium dichromate in dilute sulfuric acid or sodium hypochlorite in acetonitrile, and the preparation methods have been reviewed briefly. The specific rotation of (-)-menthone was determined and discussed with respect to the epimerization between (-)-menthone and (+)-menthone, which was corroborated by gas chromatography. This experiment covers the training in fundamental experimental skills such as reflux, distillation, extraction, filtration, gas chromatography characterization and specific rotation determination, and may help the undergraduates improve their integrative abilities and learn the knowledge of chiral compounds.

Laboratory teaching involves teaching, management, service and environment education. A good laboratory environment can not only play a subtle role in students, but also promote the development and implementation of teaching, management and service education. This article mainly introduces the practice and experience of strengthening the connotation construction of laboratory teaching environment and improving the quality of laboratory environment education of the "student-centered" at National Experimental Teaching Demonstration Center of Chemistry, Xiamen University, in order to provide a replicable and popularized construction scheme for laboratory teaching "ideological politics".

Organic molecules have become one novel type of catalysts developed after enzymes and metal catalysts, which are named as organocalysis, the third type of catalysis. As a new tool toward the precise construction of molecules, organocatalysis has a huge impact on the development of chiral new drugs, which has been used in the fields of pharmacy, pesticides, chemicals, materials, and so on. The 2021 Nobel Prize in Chemistry was awarded to German chemist Benjamin List and American chemist David W. C. MacMillan for their pioneering and important contributions to this field. This article will briefly describe chirality and asymmetric catalysis, especially, the history of organocatalysis development, its advantages and future prospects.

Copper is one of the essential trace elements in human. It plays an indispensable role in a variety of physiological activities, including electron transport, mitochondrial functions, and the activity of many enzymes. Either deficiency or excess of copper can cause serious or even fatal harm. Therefore, the uptake, intracellular distribution and metabolism of copper are strictly regulated. Disruption of the homeostasis of copper can lead to anemia, Wilson's disease and Menkes' disease, and seriously affects the brain functions. Recent researches reveal that copper is also associated with the tumor growth and the immune system. This article reviews the biological functions of copper, the function of copper proteins, and the transport and storage mechanisms of copper, and also summarizes the relationship between copper and diseases.

In this paper, an innovative experiment of instrumental analysis was recommended to detect reduced glutathione (GSH) by using commercial reagent o-phthalaldehyde. The experiment involves preparation of standard solutions, spectra analysis, and measurement of ¹H nuclear magnetic resonance (NMR) spectroscopy and high resolution mass spectrometry (HR-MS). The implementation of this experiment can help students consolidate the basics knowledge of analytical chemistry and organic chemistry, understand the frontier scientific research, cultivate the scientific research ability and research ideas, and stimulate their enthusiasm for scientific research.

For complex acid-base solution system, it is difficult to deal with the proton equilibrium condition and deduce its proton balance equation (PBE). In this paper, taking FeCl₃ aqueous solution as a model, we discuss the treatment for proton equilibrium condition, and deduce systematically the proton balance equations based on various equilibrium relations in acid-base solution. These derivation results of PBE have been verified by different methods.

In order to realize the organic integration of course ideology and politics into the physical chemistry experiment teaching, a more effective laboratory teaching mode of "student-centeredness" is implemented. In this study, based on the concept of course ideology and politics and the teaching objectives of physical chemistry experiment, we encourage and cultivate the students to explore ideological and political elements with more initiative and enthusiasm. The teacher guides the students to expound the ideological and political content in class and summarize the ideological and political content in the report, which strengthens the interaction between teachers and students. It can provide a reference for the teaching reform of course ideology and politics in related experimental courses.

Two indices addressing buffer solution are differentiated, which are used to gauge punctual and durative buffer function, respectively. Buffer strength β and buffer capacity α are accordingly suggested for the names of the indices (their corresponding mathematic expressions are differential formula and integral formula, respectively). The feasibility of introducing differential formula into calculation of durative capacity in the textbooks is intensively discussed, and the applicable conditions of this practice are pointed out, which forms the basis of suggestions for improvement on some contents of the textbooks.

The test mode of analytical chemistry experiment was reformed in order to play a better role of test scores in the performance evaluation of analytical chemistry experiment. High quality test questions database was established according to the objectives and characteristics of course. The online examination was conducted on internet online examination platform. Compared with the traditional analytical chemistry experiment written test mode, analytical chemistry experiment online examination has the advantage of simplicity and efficiency.

Chemical reaction is often associated with the energy changes. The chemical laboratory data of energy changes was recorded on the thermal imaging device made by the phone thermal imaging plug-in FLIR One Pro and smart mobile phone component. The dynamic temperature distribution in the capillary method for the determination of the melting point of naphthalene, the distillation method for the determination of the boiling point of ethanol and the dehydration reaction of concentrated sulfuric acid with paper were visualized. The images of temperature change with time in different reactions were obtained, and the color change of the images represented the energy change information of different reaction processes. This device can quickly, accurately obtain the system temperature without contact, and provides a visualization of the temperature changes invisible to the human eyes.

The content of polymer chemistry itself is complicated, which involves many concepts, principles and formulas. It is complicated and difficult for students to understand comprehensively. This paper analyzes the advantages and application value of mind mapping for teachers and students, and combines the mind mapping with the course learning of polymer chemistry to solve various problems in the teaching process, which is helpful for students to build a complete knowledge framework of polymer chemistry and achieve good teaching results.

The primary electrochemistry and colloid chemistry are the important components of physical chemistry for undergraduate students. On the basis of the nanostructured metal colloids system, a comprehensive chemistry experiment is proposed, which is about synthesis of nanostructured Ag/Au colloidal sols via the direct electrochemical reduction method with the assistance of a surfactant. In addition to the analysis of typical extinction via the UV-Visible spectroscopy, the cyclic voltammetry method is used to understand the effect of the surfactant and reveal the formation process of metal colloids. Such a comprehensive experiment is efficient to not only promote the understanding on the fundamental knowledge of electrochemistry and colloid chemistry, but also enhance the laboratory skill, which is adopted to the laboratory courses for the students majored in chemistry and related.

Constructivism emphasizes learners' initiative, and situational teaching is an important means to realize knowledge construction. "The Belt and Road" as the top-level cooperation initiative to promote the construction of the community of human destiny is a new path of global governance, also could be the core knowledge of the chemistry and society course. Based on the Belt and Road initiative, this work applies the situational teaching model guided by constructivism theory to explore the integration of chemical and social relations between the construction of China Pakistan Economic Corridor, global warming, the ice silk road, the denuclearization of the Korean peninsula, and the construction of Northeast Asia Economic Community into a complete and constructed knowledge and ideology system, and promote the chemistry and society curriculum.

Adding matrix modifier is a common and efficient method to eliminate chemical interferences in graphite furnace atomic absorption spectrometry (GFAAS). The students' understanding of the choice and mechanism of matrix modifier is only at the textbook level. In the light of this, the multiple teaching modes are adopted to make students' learning activities changed from passive to active. Through literature investigation, group discussion, induction and summary and subsequent student experiments, the matrix modifier for the determination of heavy metal ions in environmental water samples by GFAAS is discussed in depth.

Our analytical chemistry course team has successfully implemented the "XXT Full Online" teaching model in an analytical chemistry course using the Xueyin online platform, Xuexitong, Tencent meetings. This teaching mode not only gives full play to existing online course resources, but also supports a variety of teaching activities. Overall, the "XXT Full Online" teaching model breaks the time and space restrictions on teaching and learning, guaranteeing the quality of teaching during the epidemic. It also may serve as a reference for the effective implementation of online teaching.

With the rapid development of MOOC, blended teaching has become the main trend of teaching development. At present, major colleges and universities are actively promoting teaching reform and improving teaching quality with the goal of creating a "golden course". In the context of "golden course", the author combines the MOOC platform and self-built WeChat official account to arrange progressive tasks from simple to complex before, during and after class. Based on the task-driven teaching, students' studying enthusiasm is mobilized. Based on the reflection on students' feedback in the previous learning task, the upcoming task is designed and adjusted, presenting a dynamic teaching design. The "Progressive Dynamic Teaching" model is demonstrated through teaching cases, and the specific process of optimizing teaching is explained. The practical results prove that this task-driven progressive dynamic teaching helps to improve students' studying willingness and satisfactory teaching results can be obtained.

This paper focuses on the topic of course ideology and politics in analytical chemistry teaching, and the research status on this topic has been summarized. The practical exploration has been carried out on the establishment of the educational goal, teaching exploration and the teachers' accomplishment. The ideological and political goal of integrating knowledge and action is expected to be realized by the ways of precise lecture preparation, optimization of classroom interaction and construction of feedback channels.

The rapid development of short video has changed the way people obtain information. After fully integrating with the characteristics of chemistry, short video on chemistry has become an important way for popularization of chemistry, which has ushered in a new era. This paper analyzes the current situation of popularization of chemistry in short video, including tiktok's content, form and influence, and puts forward some suggestions for the development of popularization of chemistry using short videos, so as to promote the further development of popularization of chemistry in the short video platform.

Since the outbreak of COVID-19 at the beginning of 2020, students are unable to come back to study on campus. Under this situation, College of Chemistry at Jilin University organizes the online teaching of polymer chemistry for students with chemistry major (non-polymer major), followed by the offline teaching plus the construction of course ideology and politics in polymer chemistry. According to the basic knowledge and characteristics of students with chemistry major, teachers pay more attentions on developing their interests in polymer instead of just telling them to remember the knowledge, realizing the combination between ideological and political education and knowledge system education. By taking the advantages of online teaching, offline teaching and ideological and political education, the teaching quality is improved and the teaching task is completed successfully.

Determination of chemical reaction rate and activated energy is a traditional college chemistry experiment, which includes lots of theories, data treatment and graphic plotting. In order to shorten the lecture time, make students understand the theories well and master the computer technology of data treatment and graphing, an online and offline teaching model was applied. This model has gained the approval from the students and teachers, improved the teaching qualities, and achieved good results.

In the context of the reduction of lecture hours of inorganic chemistry, the teaching content of inorganic chemistry was adjusted, broadened, and deepened based on comprehensive considerations of the curriculum reform in China's high schools and the problem currently encountered by inorganic chemistry teaching. Simultaneously, based on the OBE concept, with the goal of cultivating students' abilities of independent learning, problem-solving, and innovation, several teaching methods including modularization teaching, hierarchical teaching, and seminar-style teaching were explored. An educational concept of integrating knowledge with ability was formed.

The connection and fragmentation of carbon-carbon bond is always a hot topic in organic synthesis, and scientists have been finding different ways to achieve this goal. Many achievements have been made in this field. Grignard reaction and olefin metathesis reaction are the famous and typical ones. In particular, olefin metathesis provides a new way to connect sp² carbon and sp² carbon, which suits some active molecules. Therefore, the 2005 Nobel Prize in Chemistry was awarded to three scientists who made outstanding contributions to olefin metathesis. This experiment is consisted of three reactions, including the improved Grignard reaction, DMAP-catalyzed esterification, and ring closing olefin metathesis cyclization. It is helpful to understand the process and mechanism of organic reactions and enjoy the charm of organic synthesis.

The content of the Nobel Prize in Chemistry has witnessed the development of chemistry, the inextricable connection between chemistry and human life, and the forefront of the development of chemistry. With the Nobel Prize in Chemistry as the main line, we use the interesting facts of the Nobel Prize in Chemistry to explain that the discipline of chemistry will be the basis of human survival and development, even an important contribution to human society, survival and development. We hope to make everyone realize the importance of chemistry and better understand how to carry out chemistry research, and to promote the rapid development of chemistry.

Metal-organic frameworks (MOFs) are a kind of compounds with a three-dimensional periodic network structure. MOFs exhibit excellent performance in adsorption and separation due to their high porosity, large specific surface area and adjustable pore size. This paper uses the anthropomorphic technique to show the nature, structure regulation as well as adsorption and separation applications of MOFs to the readers.

In order to achieve the purpose of student-centered, based on teaching content rearrange, information platform, and multi-dimensional assessment system, we implemented blended learning model including flipped classroom, top seminar, and interesting experiment. The blended learning model was helpful to improve individualized learning, initiative of learning, and learning motivation, and to cultivate students in aspects of knowledge, ability and quality.

The applied chemistry major is primarily associated with engineering and integration of sciences and technologies. Based on the needs of industrial development, this major actively serves the national and regional economic development, develops the characteristic direction of fine chemical industry, electrochemical engineering and polymer chemical industry, and forms the distinctive training characteristics of new engineering talents with a strong foundation and strong practical application. This paper comprehensively introduces the measures and results of the specialty orientation, training characteristics, construction of teaching staff, construction of practical teaching system and school-enterprise cooperation in education.

Boron has played an essential role in human life and production. Herein, this paper personifies Boron to describe its properties and applications in life and production. Our aim is to make it easier for readers to understand in a more lively way.

Based on the summary of the characteristics and existing problems of the instrumental analysis laboratory, the advantage of implementing virtual simulation technology was expounds. In addition, the outstanding performance of the virtual simulation laboratory teaching in dealing with special situations such as "classes suspended but learning continues" was introduced. Through questionnaires and interactive feedback, the learning situation of the students was evaluated. After pointing out the limitations of virtual simulation experiments, the teaching mode of combining online virtual simulation with offline classroom experiments was proposed, to promote the improvement of the quality of instrumental analysis laboratory teaching.

Under the new situation of education development, curriculum ideological and political education in colleges and universities faces new demands and challenges. Based on the view of students and the characteristics of chemistry science, this paper discusses the ideological and political problems in university chemistry, and proposes a number of corresponding solutions. In order to further promote the course ideology and politics, we should consider the students' value demands and improve the pertinence of the value orientation in the teaching contents; in the instructional evaluation, we should set up the communication channels between teachers and students, improve the accuracy of the evaluation activities, and enhance students' recognition of the course ideology and politics. As for the students, delivering the teaching content effectively can be achieved by changing students' learning motivation.

Activated carbon is a form of carbon materials with strong adsorption capacity. Both broad-spectrum and specificity can be regulated by preparation and processing methods. It plays an important role in removing impurities during purification processes. In this paper, the anthropomorphic method is used to demonstrate the properties of activated carbon and its classification vividly, so that readers may fully understand the family of activated carbon and its applications in fun.

The research on quantum dots has been very active in recent years. Among them, carbon quantum dots have attracted much attention due to their various advantages. In this paper, we describe the nature of carbon quantum dots and their applications in various industries by describing the development of the company and using anthropomorphic techniques. It aims to give the reader an easy and enjoyable introduction to carbon quantum dots.

Antique is the valuable cultural heritage material that our ancestors gave us. This paper reveals the chemical principle of antique aging and the "secret" of antique aging from the chemical point of view, as well as analyzes the basic chemical principle of illegal peddlers using the aging technology to intentionally fabricate. More importantly, using these chemical principles to maintain, repair and copy cultural relics is the correct way to use antique aging, which aims to let readers understand the chemical nature of aging and enhance readers' attention and concern to cultural relics.

An exploratory analytical chemistry experiment "decolorization of dye by persulfate activation", has been designed, and the students' initiative to participate actively have been stimulated through obvious experimental phenomena and application of different analytical methods. Students are led to consult the relevant reference to design the open experimental plan and exploration. In addition, different teaching plans were adopted for different levels of students, and students' laboratory skills, ability to solve practice problem and capacity to innovate was cultivated step by step.

Under the background of normal professional certification, based on the reform and revision of the talent training program for chemistry (normal) specialty of grade 2020 at the School of Materials, Chemistry and Chemical Engineering of Hangzhou Normal University, this paper reexamines the problems existing in the training program of chemistry normal specialty, from the aspects of constructing the corresponding matrix of "training objectives-graduation requirements" and "graduation requirements-curriculum system", optimizing the professional curriculum and strengthening experimental and practical teaching. The goal is to summarize and refine the characteristics of chemical education personnel training centered on students' development, and continuously promote the construction of chemical normal specialty.