Chemical modifications on certain amino acids can result in diverse effects on protein structures and functions.For this, numerous strategies have been developed for site-specific or residue-specific protein modifications.Here we summarize the latest progresses on proteinmodification based on canonical amino acids such as cysteine, tyrosine and N-terminus.
In this paper, the voltammetry experiment is taken as an example to explore how to reform the electroanalytical chemistry laboratory.The modified experiments involve advanced experimental techniques, have a better applicability and practicability, and can more effectively raise the learning interest of undergraduates in study of electroanalytical chemistry laboratory, as well as improve the teaching effect.
Based on Microsoft SharePoint application development platform, we developed the online-examination system for organic chemistry.Questions, covering the basic knowledge of organic chemistry, are given in a variety of forms.Users are allowed to modify the question bank according to their needs, and online testing is also available.This system can not only meet the students' needs of independent learning but also is convenient for teachers to manage and supervise students' learning conditions.
The present article gives examples to illustrate how to cultivate students' scientific thinking skills, awaken their interest in knowledge and strengthen their abilities to actively acquire the knowledge by themselves during inorganic chemistry teaching process at the school of pharmaceutical sciences.
The author introduces her teaching experiences in the core course of organic material chemistry lectured in English.Discussion is given in the following aspects, including selection of teaching materials, design of teaching content, improvement in professional and English ability, and feedback of teaching.Moreover, the effect and function of teaching the chemistry course in English on improving the professional knowledge and abilities in English application are also discussed.
This paper introduces the communication channels between the teacher and students in the teaching of physical chemistry, including the traditional questioning approach, homework, instant communication, Emailing, as well as cooperation and exchange methods.On the basis of respect and care, using these methods properly can make the teaching of physical chemistry more effective.
In order to strengthen fire chemistry teaching pertinence and practicability, stimulate students' interest in learning chemistry, and provide a practical teaching case for other chemical teaching, the chemical knowledge and principle used in flame retardant agent, fireproof coating, fireproof board and fire protection solution are summarized systematically combined with the flame retardant science and technology.
Making use of the modified supercritical fluid chromatograph, we measured the infinite dilution diffusion coefficients of benzene and acetone in supercritical carbon dioxide under different temperatures and pressures, and further develop an opening experiment in order to reinforce students' understanding of the supercritical fluid and properties.The depth and breadth of students' perspective will be developed.Their experimental skills will be enhanced on the basis of learning operational principle, instrumental structure, application and manipulating method of supercritical liquid chromatograph, which is beneficial to cultivate the high quality chemistry talent.
The method of using user-defined nonlinear fitting function in Origin software is introduced through examples of data processing in analytical chemistry laboratory.This method can conveniently carried out data processing, including calculating the experiment results, statistical evaluation of experimental data and creating graphs, which should be applied in analytical chemistry experiment teaching.
We discussed the relationship between the additional pressure and the stability of disperse system in detail.It was found that the reduction of additional pressure of disperse phase makes the disperse system become more stable.Taking the micro-emulsion as an illustration, the reduction of additional pressure lowers the collision probability among liquid droplets, and more importantly, it is closely associated with the formation of a strong protective film on the droplets.The disperse system could reach the thermodynamic stability state only when the additional pressure of the droplet tends to become zero, and the emulsion becomes micro-emulsion.The above discussion could also be applied to the solid/liquid disperse systems.
In this paper, two interface thermodynamics methods, the Guggenheim method and the Gibbs method, are introduced.The thermodynamic criterion of the two-phase equilibrium is established using Gibbs interface thermodynamics, and a new method for derivation of Kelvin equation is put forward based on the thermodynamic criterion of the two-phase equilibrium.
An incorrect description about the effects of the spectral bandwidth on photometry measurements is presented in domestic analytical chemistry textbooks.In this paper, a review of photometry development history was given to show that Broderson had clarified the effects of spectral bandwidth in 1954.
Based on the principle of conservation of orbital symmetry(PCOS), it can be concluded that it is the interaction between the most stable valent orbitals of diene and dienophile that determines the regioselectivity of the Diels-Alder reaction, which produces the more stable σ1 bond of the two formed σ bonds.The regioisomer which possesses more stable σ1 bond in transition state will be the main product of the Diels-Alder reaction, which is called σ1 rule in this paper.The correctness to predict the main product of Diels-Alder reaction by using σ1 rule has been confirmed by quantum-chemical calculation, and the calculation also proves that the σ1 bond forms between the most stable valent orbital of the individual reactants, diene and dienophile.
We discussed the physical meaning of the molecular partition function, and the role of both the molecular partition function and the partition function of the system in the calculation of the thermodynamic properties.It was shown that the molecular partition function is neither an extensive property nor an intensive one, but only a tie to connect the thermodynamic properties with the microscopic information of the system.
The atomic shell structure of the first to the fourth row elements were studied by the electron location function(ELF).The shell radii and population in individual shells were calculated and the relationship between the atom numbers and the atomic radii was discussed.The results could help to understand the atomic shell structure.