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2016 Volume 31 Issue 3
2016, 31(3): 1-10
doi: 10.3866/PKU.DXHX20160301
Abstract:
Glass and glassy state cover a wide range of applications. Different from liquid-crystal transition, glass transition is non-crystalline liquid-solid transition, which is not accompanied with obvious changes in structure. Therefore, we cannot classify it into any known type of phase transition. The research on the glass transition has become a key topic in condensed matter physics for several decades. However, the nature of glass state is still far away from being understood until now. Here we provide some basic physical phenomena of glass-forming systems during the glass transition, review some theoretical perspectives of the glass transition in the past few decades, and introduce some commonly used methods to investigate the structure and dynamics of glass formers, with an attempt to deepen the understanding of disordered solids and glass transition of readers.
Glass and glassy state cover a wide range of applications. Different from liquid-crystal transition, glass transition is non-crystalline liquid-solid transition, which is not accompanied with obvious changes in structure. Therefore, we cannot classify it into any known type of phase transition. The research on the glass transition has become a key topic in condensed matter physics for several decades. However, the nature of glass state is still far away from being understood until now. Here we provide some basic physical phenomena of glass-forming systems during the glass transition, review some theoretical perspectives of the glass transition in the past few decades, and introduce some commonly used methods to investigate the structure and dynamics of glass formers, with an attempt to deepen the understanding of disordered solids and glass transition of readers.
2016, 31(3): 11-16
doi: 10.3866/PKU.DXHX20160311
Abstract:
Herein the small-class-seminar-based (SCSB) teaching and the basic elements concerning the quality control of SCSB teaching are discussed. The exploratory practice of SCSB teaching in the Topnotch Students Scientific Development Pilot Program at Department of Chemistry, Xiamen University is introduced and several teaching cases are also presented.
Herein the small-class-seminar-based (SCSB) teaching and the basic elements concerning the quality control of SCSB teaching are discussed. The exploratory practice of SCSB teaching in the Topnotch Students Scientific Development Pilot Program at Department of Chemistry, Xiamen University is introduced and several teaching cases are also presented.
2016, 31(3): 17-22
doi: 10.3866/PKU.DXHX20160317
Abstract:
Aiming at the properties and some problems of physical chemistry theoretical and physical experimental courses, we discuss our experiences and methods on the association of theoretical teaching with experimental course. In addition, some experiences on the reform of physical chemistry teaching and the corresponding achievements are also discussed.
Aiming at the properties and some problems of physical chemistry theoretical and physical experimental courses, we discuss our experiences and methods on the association of theoretical teaching with experimental course. In addition, some experiences on the reform of physical chemistry teaching and the corresponding achievements are also discussed.
2016, 31(3): 23-27
doi: 10.3866/PKU.DXHX20160323
Abstract:
We attempt to offer the innovative experiment to the small-sized class in the chemical biology laboratory for the senior undergraduates majoring in chemistry. The innovative experiments are designed in terms of experimental content and pedagogy, among others, in order to foster the students' ability to apply the basic knowledge and experimental skills in the first 3 years and to further improve their comprehensive ability and creativity.
We attempt to offer the innovative experiment to the small-sized class in the chemical biology laboratory for the senior undergraduates majoring in chemistry. The innovative experiments are designed in terms of experimental content and pedagogy, among others, in order to foster the students' ability to apply the basic knowledge and experimental skills in the first 3 years and to further improve their comprehensive ability and creativity.
2016, 31(3): 28-31
doi: 10.3866/PKU.DXHX20160328
Abstract:
The problem-based method has been applied to teaching of inorganic chemistry to stimulate students' innovative thinking and scientific curiosity and to effectively raise students' innovative ability.
The problem-based method has been applied to teaching of inorganic chemistry to stimulate students' innovative thinking and scientific curiosity and to effectively raise students' innovative ability.
2016, 31(3): 32-36
doi: 10.3866/PKU.DXHX20160332
Abstract:
The heavy atom effect on 13C NMR chemical shifts is described. We analyzed and summarized the impact of bromine and iodine on the chemical shifts of carbon with different hybrid states and environment.
The heavy atom effect on 13C NMR chemical shifts is described. We analyzed and summarized the impact of bromine and iodine on the chemical shifts of carbon with different hybrid states and environment.
2016, 31(3): 37-41
doi: 10.3866/PKU.DXHX20160337
Abstract:
In this paper, the recent research progresses of copolymer via ring-opening metathesis polymerization were reviewed.
In this paper, the recent research progresses of copolymer via ring-opening metathesis polymerization were reviewed.
2016, 31(3): 42-48
doi: 10.3866/PKU.DXHX20160342
Abstract:
The oligopeptide R8 was synthesized through the solid phase peptide synthesis (SPPS) protocols, and the molecular weight was measured by MS-ESI. The biological application of R8 was investigated by agarose gel electrophoresis assay and endocytosis. Through this experiment, students can study and apply organic chemistry, polymer chemistry, and chemical biology, as well as develop their capability for analyzing and resolving problems.
The oligopeptide R8 was synthesized through the solid phase peptide synthesis (SPPS) protocols, and the molecular weight was measured by MS-ESI. The biological application of R8 was investigated by agarose gel electrophoresis assay and endocytosis. Through this experiment, students can study and apply organic chemistry, polymer chemistry, and chemical biology, as well as develop their capability for analyzing and resolving problems.
2016, 31(3): 49-54
doi: 10.3866/PKU.DXHX20160349
Abstract:
By introducing two gas buffer vessels, one for increasing pressure and the other for decreasing pressure, which can be operated independently, a new apparatus was established on the adjustment of gas pressure through controlling of air input. It was easy to control the gas pressure of buffer vessel continuously following the variation of vapor tension in different temperatures. Experimental data can be obtained when the gas and liquid are in equilibrium by manipulating the slow move of U shape liquid. This system has achieved satisfactory effects in the application for its advantages on easiness in operation, stability and data accuracy, etc.
By introducing two gas buffer vessels, one for increasing pressure and the other for decreasing pressure, which can be operated independently, a new apparatus was established on the adjustment of gas pressure through controlling of air input. It was easy to control the gas pressure of buffer vessel continuously following the variation of vapor tension in different temperatures. Experimental data can be obtained when the gas and liquid are in equilibrium by manipulating the slow move of U shape liquid. This system has achieved satisfactory effects in the application for its advantages on easiness in operation, stability and data accuracy, etc.
2016, 31(3): 55-63
doi: 10.3866/PKU.DXHX20160355
Abstract:
Determination of the second-order rate constant for the saponification of ethyl acetate has been a classical experiment in the physicochemical laboratory course for more than thirty years. In this paper, a new measurement system composed of the conductivity sensor and the computer equipped with the Nextkit Nano data acquisition card programmed with LabVIEW 2013, has been designed and constructed for multi-channel, parallel, real-time, and automatic acquisition of conductivity data. This setup has improved the teaching efficiency, and sets up an example for the future reforms of other classical experiments in chemical laboratory courses.
Determination of the second-order rate constant for the saponification of ethyl acetate has been a classical experiment in the physicochemical laboratory course for more than thirty years. In this paper, a new measurement system composed of the conductivity sensor and the computer equipped with the Nextkit Nano data acquisition card programmed with LabVIEW 2013, has been designed and constructed for multi-channel, parallel, real-time, and automatic acquisition of conductivity data. This setup has improved the teaching efficiency, and sets up an example for the future reforms of other classical experiments in chemical laboratory courses.
2016, 31(3): 64-67
doi: 10.3866/PKU.DXHX20160364
Abstract:
An improved synthesis of benzocaine is described. The synthetic route developed involves trichloroisocyanuric acid and 2, 2, 6, 6-tetramethylpiperidine-1-oxyl (TEMPO) co-oxidation system as the key step. The method could avoid high toxicity, pollution, post-processing difficulties and other unfavorable environmental factors. The reactions were carried out under room temperature for short time with high yield and safe, easy, and environment-friendly operation.
An improved synthesis of benzocaine is described. The synthetic route developed involves trichloroisocyanuric acid and 2, 2, 6, 6-tetramethylpiperidine-1-oxyl (TEMPO) co-oxidation system as the key step. The method could avoid high toxicity, pollution, post-processing difficulties and other unfavorable environmental factors. The reactions were carried out under room temperature for short time with high yield and safe, easy, and environment-friendly operation.
2016, 31(3): 68-72
doi: 10.3866/PKU.DXHX20160368
Abstract:
In different editions of Physical Chemistry, the Kelvin equation is derived with different methods. This paper analyses the pressure of curved liquid drop in the Gibbs interface thermodynamics basic equations, and gives a discussion on the derivation of the Kelvin equation.
In different editions of Physical Chemistry, the Kelvin equation is derived with different methods. This paper analyses the pressure of curved liquid drop in the Gibbs interface thermodynamics basic equations, and gives a discussion on the derivation of the Kelvin equation.
2016, 31(3): 73-77
doi: 10.3866/PKU.DXHX20160373
Abstract:
In order to reinforce the understanding of the behavior of real gas in the Physical Chemistry course, we endeavor to explain the pVm-p curves of real gas at different temperatures by van der Waals gas equation.
In order to reinforce the understanding of the behavior of real gas in the Physical Chemistry course, we endeavor to explain the pVm-p curves of real gas at different temperatures by van der Waals gas equation.
2016, 31(3): 78-81
doi: 10.3866/PKU.DXHX20160378
Abstract:
The calculation of hydrogen ion concentration is tightly associated with the conditions applied, and has been the keynote and difficulty part in study. A high degree univariate polynomial equation of hydrogen concentration was obtained by substituting the distribution fraction into the proton balance equation, and could be solved conveniently using MATLAB. Therefore, the calculation of the hydrogen concentration becomes easy as long as one can write the proton balance equation correctly. In such a way, students can better focus on learning the main knowledge of analytical chemistry.
The calculation of hydrogen ion concentration is tightly associated with the conditions applied, and has been the keynote and difficulty part in study. A high degree univariate polynomial equation of hydrogen concentration was obtained by substituting the distribution fraction into the proton balance equation, and could be solved conveniently using MATLAB. Therefore, the calculation of the hydrogen concentration becomes easy as long as one can write the proton balance equation correctly. In such a way, students can better focus on learning the main knowledge of analytical chemistry.
2016, 31(3): 82-84
doi: 10.3866/PKU.DXHX20160382
Abstract:
In this paper, the cause of liquid junction potential was analyzed with example of two different concentrations of silver nitrate. Here, we point out the difference between the total Gibbs energy and the excess charge Gibbs energy and deduce the formula of liquid junction potential. At last, the relationship between liquid junction potential and activity ratio is discussed.
In this paper, the cause of liquid junction potential was analyzed with example of two different concentrations of silver nitrate. Here, we point out the difference between the total Gibbs energy and the excess charge Gibbs energy and deduce the formula of liquid junction potential. At last, the relationship between liquid junction potential and activity ratio is discussed.
2016, 31(3): 85-86
doi: 10.3866/PKU.DXHX20160385
Abstract:
