Spectroscopic analysis is a professional basic course for undergraduates majoring in applied chemistry, and plays an important role in the graduation theses. Based on the outcome-based education (OBE) concept and the practical needs of students in graduation theses, the preliminary reforming of spectroscopic analysis course was carried out by reasonably arranging teaching content, improving teaching methods and establishing an effective evaluation system. The teaching reform focused on developing students' ability to analyze spectra and enhancing the practicality of this course.
Traditional university chemistry laboratories usually feature tedious teaching process, which may result in passive study, less or no learning interaction, and the lack of independent thinking, operation and innovation. This is bad for us to achieve the targets of comprehensive training upon freshmen in universities. With the rapid development of internet technology, a variety of information-based teaching modes have been established. Course Cubic system can merge several teaching modes, such as experiment preview, WeChat platform, and flipped class into a student-centered overall process and intelligent teaching mode. Students can conduct practice tests before experiments, record and upload experimental data in class, and carry out mutual evaluations after class. The practice shows that Course Cubic system can improve the efficiency of experiment teaching and greatly promote students' self-directed learning, increasing the interaction in experiment teaching.
Base on the teaching practice and the characteristics of the spectroscopic analysis teaching for post-graduate students in materials science in our university, the teaching objective of this course is set as "to know and understand the basic knowledge of several common spectroscopic analysis methods, such as UV-Vis absorption, IR absorption, Raman scattering, and NMR spectroscopy, and to apply the relevant knowledge to analyze and solve scientific and engineering problems". For this goal, the content, teaching methods and evaluation system of the course has been explored.
At present, the specialty of applied chemistry has been set up in 442 colleges or universities. The key issue we should urgently solve is how to make this major characteristic and have broad prospect of demands. The milestone event, that Youyou Tu won the Nobel Prize in Chemistry for the separation of Artemisinin, further highlights the importance of "research on chemical constituents of plants". Meanwhile the demand for the active ingredients of plants in human medical and health care is also increasing. After 18 years of teaching practice and exploration, closely combined with the mission of construction of "double first-class" agricultural university, we have found the first-class advantages and characteristics of cultivating the applied chemistry, a long-term specialty, in our university with the support of phytochemistry. With the landmark achievement of "phytochemistry" as the national top-quality curriculum, we have built a new undergraduate education system for applied chemistry in Northwest Agriculture and Forestry University, which is closely linked to the national major demands of double first-rate strategic plan.
Utilizing the strategy of "mind map" can instruct students to link the different elements, construct the well-defined knowledge web system and enhance the ability to sum up the knowledge. In the present paper, oriented by key competence straining, how to carry out the analytical chemistry teaching based on mind map has been described.
The corrosion law of carbon steel under different experimental conditions was studied by linear sweep voltammetry and electrochemical impedance spectroscopy. The anodic process of carbon steel was dissolving, passivating and over passivating in ammonium carbonate solution. The mass transfer of the electrode at the initial phase was controlled by linear diffusion; with the increasing of solution temperature, the impedance spectrum was expressed as a single time constant. The diameter of reactance decreased gradually, the resistance became smaller and the corrosion rate of carbon steel increased. The greater the concentration of Cl-, the smaller the passivation area, the corrosion of carbon steel increased. With the addition of the thiourea corrosion inhibitor, the increasing of the diameter of the reactance, the resistance became larger, which was beneficial to the protection of carbon steel.
This comprehensive analytical experiment has successfully introduced the frontier of science such as two-dimensional metal organic frameworks (2D MOFs) fabrication and MicroRNA (miRNA) analysis into laboratory teaching for undergraduate and graduate students whose major are chemistry or materials science. It mainly includes the following issues:synthesis and characterization of 2D MOFs, construction of 2D MOFs-DNA fluorescent probe, and developing the miRNA fluorescence biosensor. The experiment takes 10 hours. In the experiment, we adopted a new teaching mode of "game-study combination and trinity evaluation". The students learned a breadth of experimental skills, improved their experimental skills and broadened their academic vision. Moreover, through the combination of competition and teaching, the students' study enthusiasms were greatly stimulated, the spirit of teamwork was cultivated. This experiment and the teaching mode are also suitable for promotion to other comprehensive chemistry laboratory teaching.
"Synthesis and characterization of an aryl silylamine" was selected as the teaching content of "Schlenk line technique", which involves drying and assembly of glass instruments for special purposes, operation of air sensitive substances, reactions under inert gas protection, solvent concentration, extraction, distillation under reduced pressure, and molecular structure determination. In this article, the following experimental operations were discussed in detail, including the preparation of experimental devices, the transfer of solvents and reactants, a special method of transferring n-butyllithium, operations of Schlenk line, Schlenk flasks and water-free solvent flasks. The hydrogen spectra of nuclear magnetic resonance (NMR) of the aryl silylamine were analyzed. This experiment enables students to practice the experimental operations at the higher levels. This could have a good teaching effect, in broadening students' professional knowledge and improving their operating skills in comprehensive chemical experiment.
This article focuses on the synthesis of cinnamic acid. Retrosynthetic analysis and synthetic design have shown that the construction of cinnamic acid can be achieved by several protocols, including the aqueous Heck reaction, the solvent-free Perkin reaction, the aqueous Wittig reaction and the aqueous Knoevenagel reaction. These protocols extend the synthetic design thinking of students. These experiments cover the synthesis, purification and characterization of cinnamic acid, helping students understand and complete a basis scientific research process; thus, students' comprehensive ability is improved.
Knowledge of space-group and symmetrically equivalent points as well as asymmetric unit was briefly introduced according to the International Tables for Crystallography.
With careful study of the Chinese Nomenclature of Organic Compounds (2017), the major changes in the new regulations compared with the 1980 edition are summarized, including the order of main characteristic groups, the listing order of substituent groups, the numbering order of main structure, the location of substituent group and main group numbering, and the "order rule" in stereochemistry. In order to provide a reference for the study and teaching of Organic Chemistry in a concise and clear way, this paper summarizes the aspects.
In order to keep up with the trend of informationization in teaching, a gas chromatographic simulation model based on the stochastic diffusion theory was established and the corresponding computer simulation software Stochastic Diffusion-Chroma was developed in this study. The simulations of diffusion and separation of mixed particles in both packed column and capillary column were presented. The application of stochastic diffusion theory in chromatography theoretical teaching and experimental teaching were explored. The simulation teaching based on stochastic diffusion theory changes the traditional teaching mode. It transforms the abstruse chromatographic dynamics into dynamic and intuitive description, stimulating students' interest in learning and improving teaching quality.
The alkalescence hydrolysis reaction mechanism of ethyl acetate was investigated by using Gaussian 09 package. Based on the chemistry knowledge from organic chemistry, physical chemistry and structural chemistry in the regime of chemistries at universities, the strategy about how to resolve and analyze the mechanism has been elaborated in this paper, which is a useful exploration on introducing density-functional-theory computation into chemistry teaching at college.
The design ideals of inorganic and analytical chemistry experiments for the 11th National Undergraduate Chemistry Laboratory Tournament were introduced. The problems found in the competition and the analyses of the results were also provided.