Bacteria can synthesize a variety of polysaccharide molecules and secrete on the surface of bacteria to form a polysaccharide protective layer. When the bacteria are in a harsh environment, the polysaccharide protective layer can adjust the bacteria to adapt to the surrounding environment, so as to make them survive. The main polysaccharides secreted by Gram-negative bacteria include lipopolysaccharides, capsular polysaccharides and extracellular polysaccharides, which are usually effective antigens that cause strong immune response in human body and are very important for the pathogenicity of bacteria. Therefore, it is very important to study their structure and synthetic transport mechanism, which can provide innovative guidance and ideas for the target drug design of bacterial polysaccharide transport routes. This paper will focus on the structure, synthetic transport mechanism, function and influence and other aspects of bacterial polysaccharides.

The ability of logic thinking is the base of solving scientific problems and developing innovative capabilities. To develop undergraduates’ problem-solving ability, first of all, it is necessary to promote the formation and development of their logical thinking ability. Based on the characteristics of physical chemistry, this study aims to provide support for developing the logical thinking ability of the undergraduates via creating real question contexts, disassembling logical thinking, and building a process evaluation system. It proves that the designed strategies can effectively promote the development of the logic thinking ability of the undergraduates, including observation, analysis, integration, summarization, judgment and deduction.

Relying on self-built and running Shandong province online open course “physical chemistry experiment”, we have persisted in “strengthening moral education and cultivating people” and “centering on the student development” as the teaching ideas. We have comprehensively built and optimized the curriculum systems from the teaching design, the multiple teaching methods and the diversified evaluation systems, etc. The curriculum systems actively guide students to carry out inquiry-based and personalized learning, promote students’ personalized development and high-level ability training, so that the quality of talent training has been significantly improved.

There are new forms and contents in the evaluation system of basic chemistry experiment courses based on intelligent teaching platform, which is different to the three traditional evaluation modules. On the platform, the limitations of the traditional evaluation system are broken, such as the mode of evaluation management and the transmission of information. The new evaluation system can not only give a more comprehensive and objective evaluation about quality and skills to freshmen, but also improve the teaching efficiency and effect of the courses. The evaluation strategies established by practice in inorganic chemistry experiment and analytical chemistry experiment can be applied to other basic chemistry experiment courses, which will promote the curriculum value significantly.

With the aim that students mastering the preparation, characterization and property measurement methods of absorbent hydrogels in the comprehensive experimental undergraduate teaching of materials chemistry, based on the principle of safety and suitable experimental process for classroom teaching, urea slow-release gel was prepared by free radical grafting polymerization using sodium carboxymethyl cellulose, acrylamide and N,N-methylene bisacrylamide as main raw materials. The chemical composition of hydrogels was characterized by Fourier transform infrared spectroscopy. The sustained-release properties of urea sustained-release gels were determined by leaching method. The experiment has the advantages of high safety, easy to implement and moderate operation difficulty, which can provide reference for the undergraduate experimental teaching of material chemistry.

This paper provided an environmentally friendly and cost-effective strategy for turning discarded masks into high-value fluorescent carbon dot material for anti-counterfeit encryption. The design of research project-based undergraduate teaching experiment involves a multidisciplinary intersection of chemistry, materials and environment, and combination of novelty, creativity and practicality. Moreover, the microstructure, surface chemical states, electronic transitions and optical properties of carbon dots were revealed and the abilities of analyzing and solving problems from the perspective of electron, molecule, nanoscale of material chemistry were formed, enhancing students’ understanding of theoretical knowledge, execution of experiments, teamwork and creativity in scientific literacy.

Modern chemical processes use a large amount of solvent,and with timely-and-costly solvent processing. Here, we report a less solvent solid state reaction that can make 100% completion, by using a little solvent and a method to evaporate it at the end of the reaction. It has been found that the reaction of solid CoCl₂·6H₂O and solid NH₄Cl in 1∶2 molar ratio with different amount of water at 35 ℃ stops at surficial stage if no water is used, but it reaches its equilibrium if water is used, and produces sole (NH₄)₂[CoCl₄(H₂O)₂] if water is being gradually removed at the end of the reaction, which confirms the deduction of thermodynamics on LSR.

Based on the integration of real-life problems and analytical chemistry experiments, the analytical chemistry experimental course is designed as a project, taking “making a water quality monitoring report” as an example to show how students can practise the four titration methods and solve real-life problems in communication and cooperation, so as to infiltrate the concept of “output-oriented”. The concept of “student-centeredness” is implemented by integrating hand-held technology and error theory, guiding students to design and improve the experimental program, rationally allocating teaching resources, and constructing an evaluation system for the achievement of course objectives that covers both content assessment and process assessment to implement the concept of “continuous improvement” and to promote the development of the course. “Continuous improvement” concept, to promote chemistry teacher training students to meet the graduation requirements, and effectively improve the quality of personnel training.

In view of the respective characteristics of physical method, chemical method, biological method and physical chemistry method of water pollution treatment technology, a blended teaching model based on ICVE and es-online platform is constructed, combined with online course resources and virtual simulation network platform in teaching practice. Meanwhile, chemical experiment training is carried out, to guide learning through multiple channels and directions, thus students’ technical skills are comprehensively cultivated, and the effect of teaching reform is improved.

This paper proposes to build a chemistry learning community of teacher-teacher, teacher-student and student-student. The chemical knowledge points are closely combined with curriculum ideology and politics in the teaching process. We tried to deeply cultivate medical students’ spirits of great love, dealing with problems, professional dedication from medical ethics and philosophy. And we concentrated on training teachers’ innovative thinking and strengthening curriculum education function. It is vital to make a multi-angle and all-round assessment of the implementation effect of curriculum ideological and politicaleducationfrom the aspects of process evaluation, specialized course effectiveness, questionnaire results and subject descriptive feedback, which provides reference for other courses to integrate ideological and political elements and practice the fundamental task of “establish morality and cultivate talents”.

In response to the teaching challenges of a mismatch between talent cultivation in applied courses and industry demands, a dual-loop competence-growth applied course teaching mode oriented to the industry’s vocational needs was explored and developed based on the course construction philosophy of “project-driven, outcome-oriented, competence-enhancing, and value-led”. The mode consists of two improvement loops: one focused on course system enhancement based on vocational demand issues and the other centered around project-driven classroom teaching enhancements. Through the establishment of a trinity of teaching objectives based on vocational needs, the course content is reconstructed based on abilities, and the value-oriented education is carried out by emphasizing the multi-dimensional integration of vocational quality and humanistic quality. By adopting the logic of “5W1H” project analysis, a project-driven three-stage hybrid ten-step teaching method was developed, which includes immersive and interactive simulation teaching in real scenarios and assessment of course objectives aimed at achieving occupational capabilities. The reform results showed that the proposed teaching model improved students’ applied abilities effectively.

In the teaching process of titration analysis, in order to promote the deep integration of modern information technology and education, a graphical user interface (GUI) redox titration learning software was developed using Python language. The software divides the redox titration system into two types: symmetric and asymmetric titration reactions. After customizing or selecting the built-in redox titration examples, users can automatically judge the degree of titration reaction and statically display or dynamically visualize the titration curve by simply setting the titration parameters and selecting the titration medium. According to the curve image, it can calculate the stoichiometric point, titration jump range and titration error. The learning software has strong openness, flexibility, and practicality, making it easy for teachers to teach and students to learn independently. The software interface design is simple, easy to operate, and users do not need installation and professional programming knowledge. It can run directly on the Windows platform.

Molecular dynamics simulation has been widely used in scientific research fields,such as chemistry and materials,but it is rarely involved in undergraduate chemistry and material experiments.To cultivate students’ computational design thinking,and help students fully grasp the molecular dynamics simulation method,this paer designs a comprehensive computational experiment of molecular dynamics simulation on the organic electrolytes,which are widely studied in the research field of lithium-ion battery.This experimental design includes molecular and solution structural modeling,structure optimization,simulated annealing,thermal bath equilibrium,post-processing property calculation and other operations,helping students initially master the basic principles,processes and analysis methods of molecular dynamics simulation,and achieving the simultaneous improvement of theoretical method level and software operation skills.

As an important theory in fundamental chemistry, the theoryof hard and soft acid and baseremains unclear in terms of its definition, application range, and explanation during the higher education and in textbooks. In this paper, the frontier molecular orbital theory is utilized to shed light on these unclarities, mainly through a systemic discussion on the outermost shell of the central atoms. Its application range and methodology are also exemplified respectively in detail for better comprehension. In all, this paper is aimed to assist the current fundamental education and relevant research.

The proton balance equation of NaHCO₃ aqueous solution is displayed as [H₂CO₃]+[H⁺]=[OH^-]+[CO₃^2-], and the relative content of the species including H₂CO₃, H⁺, OH^-, and CO₃^2- would be changed as the analytical concentration of NaHCO₃ solution is varied. In this paper, the dynamic diagram of the concentration of each component in the proton balance equation with the solution concentration c is presented and plotted. From the dynamic diagram, the major, the minor, and the negligible species in the proton balance equation are directly and easily determined, thus, different pH formulas of solutions with different concentrations were obtained. The dynamic diagram can not only find new pH formulas, but also help students understand the physical meaning of the pH formulas correctly. It should be emphasized that the dynamic diagrams can provide new insights into the proton transfer reactions. For example,in concentrated solutions, the proton transfer reaction HCO₃^-+HCO₃^-⇌H₂CO₃+CO₃^2- dominates. In 9.1×10^-6 mol·L^-1 solution, the proton transfer reaction H₂O+HCO₃^-⇌H₂CO₃+OH^- dominates.

In 1871, Mendeleev foresaw “Ekaaluminium” based on the periodic law of elements. In 1875, Boisbaudran isolated gallium elements based on empirical research. Until the discovery of gallium isotopes in the 20th century, the development of the concept of gallium elements went through three periods of hypothesis, formation and new cognition. With the evolution of scientific thought and the progress of science and technology, the concept of gallium has continued to develop, and people’s understanding of gallium has also experienced a development process from macroscopic phenomena to microscopic essence, from hypothesis to objective reality. The discovery process of the element gallium reflects the importance of the scientific method. The discovery of gallium also facilitated the spread of the idea of periodic law.

Polycarbonate is a kind of engineering plastics with excellent comprehensive performance. Since the founding of New China, polycarbonate has been widely used in electrical, mechanical, aviation, automotive, instrumentation and other fields, and has had a significant impact on national defense, economic construction and cutting-edge technology. The article examines the development history of polycarbonate in China in the 20th century and divides it into three stages: the first one is from 1949 to 1970, referring to foreign achievements for trial production, independently establishing a hundred tons to a thousand tons of production equipment, solving the problem of polycarbonate from scratch; The second one is from 1970 to 1978, independently carrying out the quality of polycarbonate and technological research and development war to solve the problems of poor product quality; The third is 1978-2000, independently carrying out new technology development and expanding production capacity, accelerating the solution of core production technology breakthroughs and industrial scale-up problems. Based on the results of the study, the discussion is made from the perspectives of industrialization and technology, technological innovation, as well as the history of chemistry and chemistry education.