Astringency is a unique sensory experience produced by the interaction of specific chemicals with the oral cavity. This article explores the causes of astringency and provides a detailed introduction to astringent chemicals such as catechins, theaflavins, flavonoids, organic acids, and tannins. It also delves into the rich bioactivities exhibited by these astringent compounds, which have multiple benefits for human health, including antioxidant, anti-cancer, and anti-inflammatory properties. The aim of this article is to enhance public awareness of astringent substances and advocate for their rational use, not only to help people better appreciate the natural flavors of food, but also to provide an indispensable key to pursuing a healthy life.

The ability to transfer knowledge is closely related to the capacity for solving complex problems and fostering innovation. The learning process of knowledge comprises four stages: activation, acquisition, consolidation, and transfer, with the transfer stage representing the advanced phase where learning undergoes a qualitative leap from quantitative accumulation. Knowledge transfer occurs among thinking, activities, and the environment, facilitated by the generalization of common elements, the proceduralization of knowledge, and deep processing as well as modeling of knowledge. Knowledge transfer is influenced by the quantity, quality, and structure of prior knowledge, mental set, the depth of knowledge processing, metacognitive reflective ability, as well as critical and divergent thinking. During the transfer stage, teachers can achieve efficient teaching through instructional strategies such as analogical transfer, proceduralization of declarative knowledge, model-based processing, systematic problem-solving, and critical thinking instruction.

Core concepts in chemistry teaching that possess both the attributes of key teaching points and difficulties can be regarded as “threshold concepts”. They serve as the crucial “gateways” for students to develop a deeper understanding of their studies, while also acting as cognitive “thresholds” that hinder comprehension. This article, from the perspective of threshold concepts in chemistry learning, explains their connotations and characteristics, analyzes students’ learning difficulties in chemistry’s challenging areas, and accordingly proposes targeted teaching strategies, aiming to assist teachers in effectively guiding students to “cross the threshold” and overcome teaching difficulties.

This paper puts forward the idea of the design of performance assessment in interdisciplinary practice, and takes“the simulation making of heating bags”as an example, from the aspects of establishing performance assessment objectives, designing performance tasks, and formulating scoring rules, etc., this paper explains the design process of performance assessment in interdisciplinary practice. From the application of performance assessment in interdisciplinary practice, the analysis and feedback of the evaluation results, this paper explains the implementation process of performance assessment in interdisciplinary practice.

This paper explores project-based teaching practices integrating junior high school chemistry and aesthetic education, designing a 3-class-hour curriculum centered on “cyanotype cultural and creative work production”. Relying on cyanotype technology, students consolidate solution-related knowledge through experiments such as preparing 20% ammonium ferric citrate solution. Using the control variable method, they investigate the effects of exposure time, raw material volume ratio, and number of coating layers on cyanotype color depth, enhancing scientific inquiry skills. By designing and refining patterns with artistic forms like paper-cutting and plant leaves, students perceive chemical beauty through aesthetic evaluations of color and composition. This project-based approach integrates chemical knowledge, scientific methods, and artistic creation, strengthening experimental operation and variable analysis abilities while cultivating aesthetic perception and creativity, thus providing a practical paradigm for disciplinary aesthetic education.

Generative AI enabling discipline teaching has become a new trend in education, but the accuracy of GenAI’s response needs to be improved at this stage. So guiding students to improve the “human-centred mindset” has become an important AI literacy. With the theme of “dialogue with GenAI to explore the protection of metal cultural relics in museums”, the AI agent of “Nanjing Museum” is introduced as a classroom assistant, focusing on three tasks of “the nature and type of corrosion of metal cultural relics”, “the principle of electrochemical corrosion of iron cultural relics” and “the restoration and protection of iron cultural relics”, and reshaping the classroom interaction. This paper leads learners to deeply explore the mysteries of metal relics, while improving students’ human-oriented human-machine interaction ability.

The advanced understanding approaches of energy shift in chemical reactions at the stage of high school were analyzed, and the model of the subject ability system for thematic teaching of “chemical reactions and energy” was constructed by taking bunker fuel as an example of real situations. The thematic teaching is conducted from three perspectives, namely exploring the sources of ship power, analyzing the essence of energy changes in chemical reactions, and the ideas for developing novel bunker fuel. By exploring the sources of ship power, changes and development of bunker fuel, learning the definition, determination, calculation, and characterization of the reaction heat, enriching the cognitive perspective on energy change in chemical reaction system, advancing and transferring the understanding way of applying disciplines, and solving the problem of choosing novel bunker fuel, the general ideas of fuel research and development should be mastered, and the critical value of energy science and technology in the rejuvenation of the Chinese nation should be keenly understood.

To overcome the limitations of the “single-variable static comparison” approach commonly used in current educational practices, this paper proposes an experimental inquiry-based approach to construct a thinking model for analyzing factors that affect oxidizing and reducing power, with a focus on shifts in electrode reaction equilibrium. This model helps students understand how concentration and the acidity/alkalinity of solutions impact electrode reactions, breaking through traditional cognitive barriers and effectively enhancing students’ chemistry core competencies, including “evidence-based reasoning and modeling” and “scientific inquiry and innovative awareness”.

This study focused on the big ideas “properties and applications of substances” and “chemical changes of substances” in junior chemistry curriculum and developed a cognitive model to promote the development of students in integrating these big ideas. Taking the interdisciplinary practice “designing a low-carbon action plan” as the context, the study designed three core tasks for students, promoting students’ classification, change, and transformation conceptions to reach dynamic and systematic level, including: (1) identifying the key issues to be addressed in low-carbon actions, (2) selecting appropriate low-carbon action plans, and (3) systematically designing feasible low-carbon action plans. Based on the teaching process and students’ performance, the study summarized the effective strategies to integrate big ideas in junior chemistry curriculum.

The convergent intelligence classroom promotes interdisciplinary practice through problem-solving, fosters interdisciplinary understanding, develops scientific thinking, enhances interdisciplinary practical abilities and strengthens value shaping through tripartite interaction among teachers, intelligent agents, and students, as well as personalized feedback. Taking “exploring the corrosion and protection of Chime Bells of Marquis Yi of Zeng” as an example, this article studies the design and implementation of interdisciplinary practical activities in junior high school chemistry from the perspective of convergent intelligence classroom. The aim of this case study is to cultivate patriotism through local cultural relics, strengthen scientific exploration through the convergent intelligence classroom, promote literacy development through comprehensive evaluation, and solve problems through interdisciplinary practice.

Stereochemistry constitutes a vital part of organic chemistry; however, its abstract content presents certain difficulties for students to grasp and comprehend. To tackle this issue, teachers can harness the visualization of real-world scenarios, incorporating the diverse three-dimensional structures of “drug molecules”, and adopt a “structure-property-application” correlation model. By guiding students to transition from static to dynamic cognition, teachers can not only surmount the cognitive barriers posed by the abstract nature of stereochemistry but also foster the multifaceted development of students’ core literacies in chemistry.

The relationship between chemistry learning motivation and academic performance is one of the core topics in educational research, but its causal direction is still controversial. This study adopted a cross-lagged design, taking 318 junior high school students as the research subjects, and conducted two measurements within one semester to systematically examine the dynamic relationship between chemistry learning motivation and academic performance. The study found that: (1) Students’ chemistry learning motivation showed a weak but significant downward trend, and both showed high temporal stability with academic performance; (2) Chemistry learning motivation and academic performance showed significant positive correlation at the same time point; (3) Cross-lagged analysis showed that early academic performance could significantly predict later learning motivation, and early learning motivation could also significantly predict later academic performance, supporting the interactive influence model between motivation and performance, and grades had a stronger effect on motivation. The research results have important implications for chemistry teaching practice: we should focus on creating successful experiences for students, pay attention to the developmental maintenance of learning motivation, and implement personalized learning support strategies.

In this paper, the structural differences between cotton fiber and copper ammonia fiber are introduced, and a method for preparing copper ammonia fiber is described in detail. Through the analysis of each link of the experiment and infrared spectrum, it is intended to reveal the degradation of cellulose polymerization caused by peeling reaction, oxidative degradation and hydrolysis in the preparation of copper ammonia fiber, and help teachers and students understand the relevant knowledge such as material modification, hydrogen bonding and complex.

Qualitative and quantitative improvements were made to the breadth and depth of ethanol catalytic oxidation experiments. Through 50 repeated experiments, there was no unreasonable change in the mass of copper sheets before and after the reaction, and there were no copper ions in the products. The effect of copper catalytic oxidation of ethanol was quantitatively explored using an oxygen detection sensor, proving that copper was a catalyst for ethanol catalytic oxidation. By summarizing and comparing the properties of common metals and conducting exploratory experiments, we can understand the reasons for choosing copper as a catalyst. By exploring the experiments of copper catalyzed oxidation of primary alcohol, secondary alcohol and tertiary alcohol, we aim to understand the structural conditions under which alcohols undergo catalytic oxidation. Through three experiments, we have gained a deep understanding of the essence of ethanol catalytic oxidation and cultivated students’ core competencies in chemistry, including “evidence reasoning and model cognition” and “scientific exploration and innovation consciousness”.

This paper conducts a systematic analysis from multiple dimensions such as the definition, sources, aging mechanism and hazards of microplastics, and focuses on introducing the application of Nile Red staining method in the detection and identification of microplastics. To further enhance public awareness of the issue of microplastic pollution, this paper presents a set of popular science experiment schemes. Through intuitive and easy-to-operate experimental steps, it demonstrates the basic principles and operation procedures of Nile Red staining method, deepening public understanding of the problem of microplastic pollution and stimulating social attention and actions for environmental protection.

“Bond energy” is one of the important parameters of covalent bonds, which plays a crucial role in understanding or interpreting material properties. Based on students’ cognitive conflicts, by explaining issues such as “bond energy can explain the changes in the thermal stability of halides, but cannot explain the strength of the acidity of hydrogen halide acids”, and appropriately guiding attention to the different reaction mechanisms of “free radical reactions” and “ionic reactions”, it can effectively promote the accurate understanding and learning of the connotation and application conditions of the concept of bond energy, break through the misconceptions generated in the process of concept learning and application, and develop the core literacy of chemistry.

Evaluating the suitability and scientificity of the “Gas Stove Adjustment” test and reference answers in the textbooks from the perspectives of point, situation and question. Providing proof in accordance with the requirements for gas interchangeability. Contacting and analyzing the new life situations, and redesigning the tests according to the point of textbook tests and the actual teaching of chemistry in high schools.

A systematic review of the national science education policy texts in recent years reveals that China’s science education is undergoing an overall transformation centered on the cultivation of national strategic scientific and technological forces, the improvement of the scientific literacy of the entire population, and the nurturing of an innovative culture. The state not only emphasizes the inclusive improvement of scientific literacy but also focuses on the deep integration of the scientific spirit and social civilization, embodying a value orientation that places equal emphasis on individual development, strategic support, social responsibility, and educational equity. During the process of curriculum reform, scientific practice has been increasingly strengthened. The construction of a comprehensive science education ecosystem is ongoing, the evaluation mechanism needs to be followed up, and digital means should be used to bridge the urban-rural gap. In the future, the implementation of policies will be promoted through the professional construction of teaching staff, balanced allocation of resources, and the guarantee of supervision and financial support systems.