In this review, the discovery of tungsten element, tungsten and its alloys, tungsten-containing polyoxometalates, tungsten oxide, tungsten carbide, layered tungsten dichalcogenides and quadruply bonded complexes are introduced.

Addition type phosphazene flame retardant has the advantages of good thermal stability, good weather resistance, low smoke, low toxicity, low added amount and low moisture absorption. It has been widely used in the field of flame retardant polymer materials. This paper reviews the research progress of added phosphazene flame retardants in polymer materials in recent years, and analyzes the research status of phosphazene flame retardant using in polymer materials. It also provides reference for the design of novel phosphazene flame retardants.

SPSS and Origin are used as the main data analysis tools to analyze the scholastic achievements of final exams college undergraduate of Institute of Chemical Engineering. It was found that the samples could be divided into three groups according to the proportion of 20%, 50% and 30% by fitting the residuals of the simple linear fitting of the average grade points in descending order, and differentiating the fitting function. Similar results can be obtained by hierarchical clustering, which suggests that there may be deep connections between the two algorithms. It was significantly different that the composition of achievement rates of credits and the distribution of standard deviations in different groups found by the research. This article analyzes the characteristics of students in different groups, speculates on possible causes, and puts forward corresponding management opinions for reference of relevant personnel.

This article introduces the blended teaching design of fluoride in inorganic chemistry courses based on Moso Teach. This teaching design combines mobile phone with teaching reasonably, making mobile phone a powerful learning tool for students. In the process of teaching, some questions are designed in the classroom according to the teaching content,and every student participates in funny and active learning process by use of the functions of "brainstorming", "answer discussion" or "group task" in Moso Teach. Teacher can understand the changes in students' cognition and interests by use of the function of "Vote/Questionnaire" in Moso Teach, and improve the teaching methods on this basis. According to the survey, the classroom teaching can be promoted by the Moso Teach and this teaching design was accepted by most of students.

It is difficult for students to learn inorganic chemistry because of its abstruse theory and complicated calculation. This paper optimized the teaching design of "galvanic battery principle and application" and improved teaching methods according to the characteristics of inorganic chemistry and properties of undergraduate. The paper introduced the galvanic battery principle and its application in determining the concentration of pH and ion, electrochemical biosensor. This will help to cultivate new exploration of scientific research consciousness gradually in the undergraduate inorganic chemistry teaching.

Polymer materials synthesis experiment is the core experimental course of polymer program. How to establish an effective link between experimental course and theoretical course, and deepen students' understanding of the knowledge points they have learned and make full use of them are the main objectives of this course. For this sake, the author and the teaching team proposed:introduce comparative experiments in the teaching class by changing experimental parameter in the same experiment. To understand the different experimental phenomena and material performance differences caused by these changes, we guide students to carefully observe the phenomenon and use knowledge in theoretical course to analysis the mechanism of these phenomena in-depth. This trial has effectively changed the uniform operation and almost identical experimental phenomena and results in the previous experimental teaching course, effectively stimulated the initiative of students, and improved their ability to analyze and solve problems. The feedback of this course during the last two years shows that the introduction of comparative experiment and phenomena-driven knowledge mining have effectively consolidated the knowledge points of theoretical classroom and made it possible for students to creatively study and apply.

A comprehensive experiment was designed with the title of preparation and performance test of solid oxide fuel cell. Experimental contents include the preparation of the electrolyte and electrode powder, the compression of cell foils, the preparation of symmetrical electrodes, the characterization of powder structure by X-ray diffractometer, as well as the test and analyses of the electrochemical properties of cells by the electrochemical workstation. This experiment can not only practice students' basic experimental operation skills, but also improve the students' learning interests alongside with practical ability and cultivate the students' innovative consciousness and team work spirit.

Fabrication of visualized and standardized analytical chemistry experiment teaching mode was discussed from the following aspects in this paper, including combination of multimedia computer-assisted instruction with traditional methods, integration of video of basic experiment procedure and experiment process, collection of experimental data by two-dimensional code scanning technology and analysis of the experimental data through computer programming. Years of practice showed that teaching effect was effectively improved after the innovation. The average score of experimental report reached about 90 points in the experimental class. Data processing capability of the students was generally improved. Passing rate of the final examination reached 90%, with the average score about 75 points. Student's initiative for scientific research was further stimulated. More than half of the students took part in national, Tianjin and school university student innovation program. Experimental skills of the students was obviously improved. Two first prize, two second prize and two third prize were achieved in the Tianjin university chemistry competition during the recent two years.

The active chlorine in 84 disinfectant was determined by back titration. The active chlorine in 84 disinfectant and K₂Cr₂O₇ can be quantitatively reacted with Fe²⁺ in the sulfuric acid. The excess Fe²⁺ in the active chlorine react with 0.001 0 mol/L K₂Cr₂O₇ standard solution, and active chlorine content was calculated. Active chlorine within 0~5.50 mg was linearly dependent on the K₂Cr₂O₇ standard solution, the correlation coefficient is 0.999 8 and the detection limit of the method (3S/k) is 6.8 μg. This methods for the determination of active chlorine in samples was simple, fast, and less interference than traditional titration. The relative titer is T_{NaClO/K2Cr2O 7}=0.248 3 mg/mL.

The extraction and separation of spinachrome constitutes a very important section in organic chemistry experiment of chemistry and chemical engineering specialty etc. But there exist some problems such as taking long experimental time, using too much solvent and making serious environmental pollution. In this paper, a series of factors including the spinach dosage, extraction solvent amount, stationary phases, column chromatography size, elution solvents and their dosage were explored using the semimicroscale and microscale technique. It has been found that the main pigments in spinach were well separated in 29 min over 4 grams of silica gel as the stationary phase using 51 mL of petroleum ether and ethyl acetate (3:2) as the elute, after sequential extraction with 5 mL of methanol, and 5 mL of the mixture of petroleum ether and methanol (3:2), respectively, in a scale of 5 grams of spinach leaves as the staring material.

This study investigated the structure and level of 189 preservice chemistry teachers' based on quantitative research methods. Results indicated that (1) the structure of preservice chemistry teachers's PCK mainly included four components, such as KoC, KoL, KoA, KoS and had good reliability and validity; (2) there was significant correlation among the four components of PCK, and the explicit PCK teaching method was more favorable to the integration of the components than the implicit ones; (3) the level of KoS was relatively ideal, while the other three components are at medium or lower level; (4) there was a significant difference in the level of PCK under different teaching method (explicit or implicit) of PCK.

The structure teaching mode was developed for the teaching and learning of pharmaceutical analysis based on the logic that the properties depend on chemical structures and the analytical methods depend on properties. The practical teaching process proved that this method can relieve stress of learning and teaching obviously at the same time, also improve the teaching effect. The average score increased 6.9 in the three years before and after the implementation of this method.

Precipitation-dissolution equilibrium occurs in heterogeneous systems. This phenomenon is widely existed in medicine and life science, such as the formation of bones, dental caries, renal calculi and urinary calculi and so on. In order to enable medical students to better understand and master the knowledge of precipitation-dissolution, the author started with medical cases through the "problem-oriented" teaching mode, and ended with the causes and preventive measures of diseases. So the way of ending corresponded to that of starting. This teaching form shows the interaction between a teacher and students. It brings about very effective teaching, helps students learn with problems, and stimulates students' interests in learning and their subjective initiative. It also helps develop students' abilities to explore and solve a problem. Thus, students have chances to become men who have an ability of exploration with independent and innovative thinking. What we discussed here can be applied to other chapters of Basic Chemistry in Medication, which is of great guiding significance.

The online testing and learning platform for organic chemistry experiment course was designed and developed to improve the teaching of organic chemistry experiment. The platform, which was based on open source examination system, could adapt to various terminals and operating systems without installing the client separately. Firstly, the evaluation index system of experimental ability, which met the objectives and needs of organic chemistry experiment teaching, was constructed. On this basis, the platform was built, and the standardized test database and teaching resources database are constructed. In addition to the basic functions of the examination system, the platform could also push related learning materials according to the test results to achieve personalized and targeted teaching. The practice has proved that the platform could help students master experimental knowledge and help teachers understand the teaching effect.

Through the measurement analysis and reading summary of the literature, it was found that the Chinese physical chemistry curriculum and teaching research is still limited to experience and speculation. We sorted out literature on physical chemistry teaching in international authoritative journals and classified them into textbooks, study, teaching research, teacher research and teaching media research, and reviewed the core achievements. It concludes that foreign physical chemistry courses and teaching research focus on the collection and analysis of learning evidence, focus on the application of educational research methods, and make suggestions for the future of higher chemical education research.

Belgian industrial chemist Ernest Solvay's scientific public welfares were introduced, including the Solvay Conference, Solvay Society and Chemistry for the Future Solvay Prize. The development and current status of these scientific public welfares were described. The practical significance of industry feeding scientific research to promote scientific spirit and development was revealed.