Online First

View All
Please wait a minute...
  • Study on the Relationship between the Theoretical Plate Number and the Mass Transfer Unit Number in Chemical Unit Operation
  • LI Xuehui, CHEN Liang, WU Zhengshun
  • Packed tower and plate tower were common equipment in the operation of chemical units. The calculation of the height of the packing layer in the packed tower and the determination of the number of theoretical plates in the tray tower were the key. The calculation of the height of the packing layer in the textbook was based on the mass transfer unit, and the determination of the theoretical plate in the plate tower was determined by the McCable-Thiele method, and the relationship between the number of mass transfer units and the theoretical plate was less. In this paper, The mass transfer unit number and the theoretical plate number were respectively calculated by the absorption factor method in detail, and the quantitative relationship between them was established. It could be used for the comparison of the two type towers, which had a certain guiding role for the analysis and design of the tower, and helped students to learn and understand the process of absorption and rectification unit operations.
  • DOI:10.3866/PKU.DXHX201905062     Published online: 2019-06-18
  • Download PDF
  • The Biography of Silicon
  • YANG Luming, ZHU Yaxian
  • Silicon is the second most abundant element in the earth’s crust, and its compounds are indispensable in our production and life. The application and prospect of Silicon and its compounds are described in this paper from the perspective of Silicon’s past life, present life and future.
  • DOI:10.3866/PKU.DXHX201905065     Published online: 2019-06-18
  • Download PDF

Recommend

View All
  • Construction of a New Chemistry Experiment Teaching System for Cultivating Innovative and Entrepreneurial Talents
  • Dongcai GUO,Yuzhi WANG,Yongjun LI,Chaoyang WU,Haoran LIU,Shuanglian CAI,Na GAO,Chi CAI
  • Focusing on the ability cultivation issues of chemistry and chemical engineering undergraduates in laboratory teaching for innovative and entrepreneurial talent cultivating, a new chemistry experiment teaching system was constructed through the interaction of laboratory teaching contents, scientific research and social applications. In this system, experimental skill training, knowledge transferring ability training, innovation and entrepreneurship training were integrated and supported each other. In addition, this system extended from in-class studies to extracurricular practices, and kept four years innovation and entrepreneur training for the undergraduates in a continuous manner. This innovative practice teaching system has already been performed and achieved good teaching effects.

  • 2019, Vol.34 No.4 DOI:10.3866/PKU.DXHX201809007
  • Download PDF Article HTML
2019 Vol. 34,No. 6Published:28 June 2019
Study and Reform of Chemical Education
  • Reflection and Practice on Teaching Reform of Spectroscopic Analysis Based on OBE Education Concept
  • WANG Yaqi, WANG Liying, JIA Huijie, WU Ruifeng
  • 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.
  • 2019, 34 (6): 1-4 DOI: 10.3866/PKU.DXHX201810038
  • Reform and Practice of Teaching Modes in University Chemistry Laboratories Based on Course Cubic
  • MA Haifeng, LIU Bin, LU Changsheng, ZHOU Aidong, TIAN Xiaocong, WANG Fengbin
  • 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.
  • 2019, 34 (6): 5-10 DOI: 10.3866/PKU.DXHX201811023
  • Practice and Reflection of Spectroscopic Analysis Teaching for Post-Graduate Students in Materials Science
  • WANG Nannan, CHENG Haifeng, YU Jinshan, TANG Dan
  • 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.
  • 2019, 34 (6): 11-18 DOI: 10.3866/PKU.DXHX201811027
  • Exploration on the Construction of Phytochemistry Curriculum System Based on First-Class Undergraduate Teaching
  • GAO Jinming, GENG Huiling, WANG Junru, ZHANG Jiwen, ZHU Wei
  • 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.
  • 2019, 34 (6): 19-25 DOI: 10.3866/PKU.DXHX201810012
Chemistry Laboratory
  • Improvement in the Experiment of Corrosion of Carbon Steel in Ammonium Carbonate Solution
  • DU Yanfang
  • 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.
  • 2019, 34 (6): 33-37 DOI: 10.3866/PKU.DXHX201810034
  • Comprehensive Analytical Chemistry Experiment on MicroRNA Fluorescence Sensor Based on Two Dimensional MOFs Probes and New Teaching Mode of “Game-Study Combination and Trinity Evaluation”
  • GAN Ning, YANG Qian
  • 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.
  • 2019, 34 (6): 38-45 DOI: 10.3866/PKU.DXHX201810003
  • Selection and Teaching of Synthetic Experiments with Air-Sensitive Substances in Comprehensive Chemical Experiment
  • ZHAO Xiaoxia, BAI Yinjuan, LIU Jingjing, CHENG Hecong, XIE Gang
  • "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.
  • 2019, 34 (6): 46-52 DOI: 10.3866/PKU.DXHX201810023
  • An Exploration of the Design-Oriented Experiments: The Retrosynthetic Analysis, Design and Preparation of Cinnamic Acid
  • ZHENG Yuan, LAN Quan, ZHA Zhenggen
  • 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.
  • 2019, 34 (6): 53-59 DOI: 10.3866/PKU.DXHX201811009
Between Teacher and Student
  • Study and Thoughts about the Questions of “Order” for Chinese Nomenclature of Organic Compounds in the 2017 Edition
  • ZHAO Shujie, LI Mingtang, ZHU He, HONG Bo, LIU Wencong
  • 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.
  • 2019, 34 (6): 66-71 DOI: 10.3866/PKU.DXHX201811025
Self Studies
  • Teaching Chemistry with Chromatographic Simulation Based on Stochastic Diffusion Theory
  • SUN Yinlu, WANG Ziyao
  • 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.
  • 2019, 34 (6): 72-80 DOI: 10.3866/PKU.DXHX201811029
Chemical Olympiad Competition
2019, Vol.34 No.5  No.4 No.3 No.2 No.1
2018, Vol.33 No.12  No.11 No.10 No.9 No.8 No.7
No.6 No.5 No.4 No.3 No.2 No.1
2017, Vol.32 No.12  No.11 No.10 No.9 No.8 No.7
No.6 No.5 No.4 No.3 No.2 No.1
2016, Vol.31 No.12  No.11 No.10 No.9 No.8 No.7
No.6 No.5 No.4 No.3 No.2 No.1
2015, Vol.30 No.6  No.5 No.4 No.3 No.2 No.1
2014, Vol.29 No.6  No.5 No.4 No.3 No.2 No.1
2013, Vol.28 No.6  No.5 No.4 No.3 No.2 No.1
2012, Vol.27 No.6  No.5 No.4 No.3 No.2 No.1
2011, Vol.26 No.6  No.5 No.4 No.3 No.2 No.1
2010, Vol.25 No.6  No.5 No.4 No.3 No.2 No.1
2009, Vol.24 No.6  No.5 No.4 No.3 No.2 No.1
2008, Vol.23 No.6  No.5 No.4 No.3 No.2 No.1
2007, Vol.22 No.6  No.5 No.4 No.3 No.2 No.1
2006, Vol.21 No.6  No.5 No.4 No.3 No.2 No.1
2005, Vol.20 No.6  No.5 No.4 No.3 No.2 No.1
2004, Vol.19 No.6  No.5 No.4 No.3 No.2 No.1
2003, Vol.18 No.6  No.5 No.4 No.3 No.2 No.1
2002, Vol.17 No.6  No.5 No.4 No.3 No.2 No.1
2001, Vol.16 No.6  No.5 No.4 No.3 No.2 No.1
2000, Vol.15 No.6  No.5 No.4 No.3 No.2 No.1
1999, Vol.14 No.5  No.6 No.4 No.3 No.2 No.1
1998, Vol.13 No.6  No.5 No.4 No.3 No.2 No.1
1997, Vol.12 No.6  No.5 No.4 No.3 No.2 No.1
1996, Vol.11 No.6  No.5 No.4 No.3 No.2 No.1
1995, Vol.10 No.6  No.5 No.4 No.3 No.2 No.1
1994, Vol.9 No.6  No.5 No.4 No.3 No.2 No.1
1993, Vol.8 No.6  No.5 No.4 No.3 No.2 No.1
1992, Vol.7 No.6  No.5 No.4 No.3 No.2 No.1
1991, Vol.6 No.6  No.5 No.4 No.3 No.2 No.1
1990, Vol.5 No.6  No.5 No.4 No.3 No.2 No.1
1989, Vol.4 No.6  No.5 No.4 No.3 No.2 No.1
1988, Vol.3 No.6  No.5 No.4 No.3 No.2 No.1
1987, Vol.2 No.6  No.5 No.4 No.3 No.2 No.1
1986, Vol.1 No.4  No.3 No.2 No.1