Although the natural silk has good and unique performance, there are several physical defects, such as poor mechanical properties (tensile strength and toughness), short life time and poor color fastness. Scientists have developed new technologies of silk modifications to improve their performance and achieve better applications. At present, the commonly used methods of silk modifications mainly include gene modification method, physical method, chemical method, and feeding method. In this short review, firstly, the structure of silk and their modification principle are summarized, and then the important progress made in recent years on the four kinds of modification methods are introduced. Finally, the challenges on modified silk field and the future development are prospected.

Photocatalysis is a kind of important and special catalytic reaction with dual properties of photochemical reaction and catalytic reaction. It has been widely used in many fields, but not involved in undergraduate education of physics chemistry. In this work, we put emphasis on expounding the importance of incorporating photocatalysis into the relevant chapters of physics chemistry, propose the construction of textbook writing, and introduce application, reaction mechanism and chemical kinetics of photocatalysis.

Boiling point under atmospheric pressure and saturated vapor pressure are commonly used to assess the ability of pure substances' volatilization. The reason why these two indicators can used to evaluate pure substances' volatilization is not clear and thermodynamic analysis is not completed. In this paper, thermodynamic analysis of pure liquid's volatilization was studied, and the thermodynamic model was established according to the second law of thermodynamics. Meanwhile, thermodynamic analysis of whether the molar enthalpy of vaporization at boiling temperature under atmospheric pressure act as a criterion for the volatilization of pure substances was carried out. The results show that the molar enthalpy of vaporization can be used as a new criterion for the volatilization of pure substances. The smaller the molar enthalpy of vaporization, the more easily the pure substances volatilize, and vice versa.

The basic thermodynamic expression dF=δW' of a reversible process is used to deduce Laplace equation, Kelvin equation, Perrin equation, Young's Equation, the liquid height in capillary tube and other thermodynamic formulas, and a general method of how to conduct such kind of deduction is summarized.

In order to strengthening students' basic theoretical knowledge,enhancing students' practice ability and innovative ability, the multi-level training system(that is the training of basic theory,the training of operation technology and the training of function application)is established in the experiment teaching of large-scale instrumental analysis. It is proved that the multi-level training system set up platform for exchanging ideal between students and experts. The system from theory explanation to operation, and then to application breaks the limit of mode of traditional experiment teaching and improves scientific research ability of analyzing and solving problem.In addition, the training system can improve the using rate of large-scale instrument and culture a lot of professionals.

We designed an undergraduate instrumental experiment to study the effects of pH on peptide separation by capillary zone electrophoresis (CZE). Five peptides, Bradykinin,[Hyp³]-bradykinin, Angiotensin I, Leucine Enkephalin and[Met⁵]-Enkaphalin, were analyzed. Both electroosmotic flow (EOF) and analyte adsorption which strongly depend on the pH, the most important issues in bioanalytical CE, were evaluated. Peptide adsorption is not observed at pH 10 for acidic peptides but weak adsorption is observed for basic peptides. Basic peptides show strongest adsorption leading to poor separation at intermediate pH 6. At pH 2.3 peptides are well resolved and show no adsorption due to their positive charge state. However, the EOF disappears at pH 2.3. This experiment is beneficial to the students who already have a basic knowledge background in analytical chemistry. It helps the chemistry students to understand the effects of environmental factors in instrumental separation analysis.

Mass balance method(MB), ¹⁹F quantitative nuclear magnetic resonance (¹⁹F-qNMR) and differential scanning calorimeter (DSC)were used to determine the content and purity of leflunomide. The result from ¹⁹F-qNMR (100.2%) is similar to that from MB (99.7%). Meanwhile, the purity result from DSC (99.92%) is comparable to that from HPLC test (99.78%). All the three methods could be used to characterize the assay or purity of leflunomide. The methods could be applied to confirm each other and improve the drug quality control.

Isolation of caffeine from tea leaf is one of the classic experiments in organic chemistry experiments. In this study, the traditional sublimation apparatus was changed to be more simple and efficient. Meanwhile, the aggregation and growth of the crystal of caffeine can be observed directly. The amount of caffeine can be collected and calculated easily. The thin layer chromatography was used to determine the components in the extracting solution. The new experiment process enriches the experiment lesson and decreases the possibility of mistake. It is safer than the traditional one. Furthermore, the conjunctive use of microscopic melting point meter and smart phone successfully photographed the morphology of the caffeine crystal and bring the interest to this classic experiment.

The pyridineimine iron and cobalt complexes have been synthesized and investigated as precatalysts for isoprene polymerization in the presence of dichloroethyl aluminum as a cocatalyst. The microstructure of the obtained polymer was also characterized by nuclear magnetic resonance (NMR) and infrared spectroscopy(IR). This experiment covers three aspects of organic synthesis, complex synthesis and polymer synthesis, which is conducive to the comprehensive training of students' experimental skills.

As an important physical property data of liquid, surface tension are widely used in many fields, such as scientific research, industrial production and everyday life. The experiment design on determining the liquid surface tension by Wilhelmy method is introduced in detail. The merits of this experiment are simple process, high accuracy, easy to adjust the experimental contents and time. This experiment is helpful for cultivating the students' careful scientific style.

According to copolymer composition equation and relation between monomer composition and conversion ratio by using the monomer composition as an intermediate variable, a graphical user program for plotting the relationship between copolymer composition and monomer conversion rate of two-component copolymerization was developed with the Matlab GUI as a tool. The application of copolymerization of styrene with Methyl methacrylate-Styrene (MMA-St), Acrylonitrile-Vinyl acetate(AN-VAc) can be demonstrated:This new graphical user program has friendly interface, strong interactivity, wide applicability and convenient calculation. It can solve the difficult problem that the relation between the composition of polymer and monomer conversion is too complex to find the direct relation in the process of drawing. It can provide theoretical basis for predicting the variation of copolymer composition and conversion rate, controlling copolymer composition, selecting control method, verifying experiment and guiding production.

The Gaussian software was introduced for the interpretation of the solvation effect on the vibrational feature of specific group in the molecule. Structural optimization and infrared spectrum calculations were performed for N-methylacetamide and acetonitrile in different solvation environments, respectively. The results show that the solvent induced frequency shifts of specific vibrational motion are according to the interactions between solute and the solvents with different polarity. The correlations among the solvation environments, molecular structure, and the frequency shift revealed by Gaussian calculations are quite helpful for the students' understanding about the solvation effect on the infrared frequency shift, and also for the improvement of class teaching, and further inspiring the students' motivation in learning.

This paper bring to light an interesting phenomenon:if hybridization of valence orbital of central atom A is sp³d and there is lone electron pair in the orbital for polyatomic molecules AB_n, the lone electron pair always occupies an equatorial position; and if there is polybond between A and B in the molecule, B always occupies an equatorial position. It inquired into the internal cause of the phenomenon and demonstrated the rule by inductive method.