Table of Content

26 November 2020, Volume 39 Issue 6

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Recollements of Derived Categories of Gorenstein Algebras

QIN Yongyun

2020, 39(6):  1-4. 

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This paper mainly studies Recollements of derived categories of Gorenstein algebras.Let A and C be Gorenstein algebras,it is proved that a 2-recollemet of the derived categories (DB, DA, DC) can be completed to an unbounded ladder. This recollement induces an unbounded ladder of period 2 between their stable categories of Gorenstein projective modules.

Application of Jacobian Matrix and Determinant in Science and Technology

WANG Wenting, JIANG Long, PEI Qiming

2020, 39(6):  5-8. 

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Jacobian matrix and its determinant are important computational tools in science and technology. This paper summarizes the important roles of Jacobian matrix and its determinant in coordinate transformation, derivative transformation and linear approximation for functional integration, robot dynamics, thermodynamics, nonlinear dynamics, and stochastic dynamics to deepen the understanding of Jacobian matrix and its determinant.

Preparation and Electrochemical Performance of a New Type of Nitrogen-Containing Heterocycle Loaded Cobalt Electrode Material for Lithium-Ion Battery

ZHENG Jiayu, YANG Runfang, YAO Shiwen, CAI Yuqing, SHU Bo, XIA Shubiao

2020, 39(6):  9-14. 

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Lithium-ion batteries with the characteristics of high working voltage, high energy density, low self-discharge rate, and no memory effect, have become an indispensable energy storage technology in the future. A kind of organic-inorganic hybrid material HAT-Co, which is similar to MOF structure with dual active sites, has been successfully synthesized. The material is first used as an anode material for the lithium-ion batteries. The material has a coral shape when it is analyzed by the SEM topography. By comparing several different synthesis conditions, the XRD diffraction peaks are basically unchanged and the crystallinity is good. In the case of a current density of 100mA/g, a large capacity of 698mAh/g can be reached after 50 cycles. After 500 cycles at a current density of 800mA/g, the capacity retention rate of 95% can still be maintained. The excellent electrochemical performance of HAT-Co electrode material is mainly due to its unique structure and dual active redox active sites. The synthesis and application of this material have theoretical guiding significance for breaking through the bottleneck of lithium-ion battery research, and have practical application value for promoting the development of new electrode systems.

Physical and Chemical Properties of Fe_n-mSi_m Clusters with n=2~6 Atoms via Density Functional Theory Calculations

YU Shiwen, ZHEN Shaocong

2020, 39(6):  15-26. 

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The structural, magnetic, and chemical properties of Fe-Si clusters with two to six atoms are studied by using the density functional theory at the B3LYP level. The structural optimization is calculated at different multiplicity in order to get the stable structure. The cationic cluster and anionic cluster corresponding to the stable structure are computed at the same level. The clusters behavior is basically governed by the Fe-Fe interaction and to a lesser extent by the Fe-Si and Si-Si interactions. A tendency for Fe-clumping is observed. The affinity, ionization potential, chemical potential, HOMO-LUMO gap, and magnetic moment are studied. For a given cluster size, magnetic moments increase with mostly by 4μB per Fe –substitution coming from the iron d-states. The molecular hardness (η) is directly proportional to ionic potential, which is independent of the size of cluster.

Effects of Organic Fertilizer on Physical and Chemical Properties and Pb and Cd Morphology of Red Soil

WANG Sitao, CHEN Jinli, YANG Haizheng, XIA Rong, ZHAO Shuai

2020, 39(6):  27-33. 

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The red loam samples are collected from the Zone of Economic and Technological Development in Qujing. Having been polluted by heavy metal Pb/Cd, the soil samples are treated with two kinds of organic fertilizers with different concentrations, and their physical and chemical properties and heavy metal contents in different forms are determined. The effects of the two kinds of organic fertilizers on the physical and chemical properties and morphology changes of Pb and Cd of the red soil polluted by heavy metals are studied. The results show that the nitrogen, phosphorus and potassium content in the red soil increase significantly after the application of soil organic fertilizer (A). The nitrogen, phosphorus and potassium content in the red soil has not improved obviously after applying Dvo (B). At the same time, the two kinds of organic fertilizers can effectively reduce the proportion of exchangeable Pb in the polluted soil, increase the organic binding state and residue state in the soil, but lead to the increase of both exchangeable Cd and residue Cd content in the soil. The results also show that application of an organic fertilizer could significantly improve the nitrogen, phosphorus and potassium content in the red soil, while application of organic fertilizer B could not significantly improve the effect. Both of the two organic fertilizers can be used as remediation agents to weaken the harm of Pb, but the repair effect of Cd is not ideal.

Microwave Conversion of Carbonate Hydroxyapatite and Its Adsorption of Cu²⁺ and Cd²⁺ from Wastewater

XU Jiao, LIU Peng

2020, 39(6):  34-39. 

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The domestic hen eggshell waste as raw material has been effectively utilized to produce flower-like carbonate hydroxyapatite (CHAP) by using microwave irradiation liquid-phase method with the help of ethylenedia-minetetraacetic acid (EDTA) as a complex agent. X-ray diffraction (XRD),fourier transform infrared spectroscopy (FTIR),and scanning electron microscope (SEM) were used to analyze the phase composition and morphology of CHAP. The influence of various parameters on adsorption process such as solution pH, contact time, amount of CHAP, and initial concentration of metal ions were studied at 25 ℃ to optimize the conditions for maximum adsorption. The results showed that the flower-like b-type CHAP can be prepared by the microwave-liquid-phase method. The removal efficiency of Cd²⁺ and Cu²⁺ by CHAP could reach 94 and 93.17%, respectively, when the initial Cd²⁺ and Cu²⁺ concentration was 50 mg·L^-1, the liquid/solid ratio was 3 and 2 g·L^-1, pH values was 6 and 7, and the adsorption time was 70 min. The kinetic equation corresponds to the pseudo second order and the equilibrium sorption data for at 25 ℃ could be described by the Langmuir isotherm models. Their correlation coefficients were 0.9880 and 0.9939,respectively. The highest values of Langmuir uptake were found for copper (40.98 mg·g^-1) and cadmium (35.59 mg·g^-1).

Study of Metal-catalyzed Bicyclization of Constructing Five/Six-membered Pyrrole Skeletons

FAN Wei

2020, 39(6):  40-44. 

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Pyrroles can be used as analgesics, anti-inflammatory drugs, EP1 receptor antagonists, etc. At the same time, the skeleton is also widely present in natural products such as Isamoltane, Obatoclax and Tolmetin, and it is one of the most valuable heterocycles. The metal-catalyzed bicyclization reaction has been widely reported in the construction of five-membered and six-membered pyrrole. How to make full use of the advantages of the existing literature and avoid the repetition of shortcomings will provide a reference for the research on the new method of pyrrole synthesis.

Study of Problems about Calculation of Entropy Change in Physical Chemistry

CHEN Yishan

2020, 39(6):  45-49. 

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The entropy change of a system can be used to determine the direction of a process, which plays an important role in teaching thermodynamics. There are diversity and flexibility in the problems about calculation of entropy change, which are the difficulties in teaching. Four kinds of problems of calculation of entropy changes have been discussed by the case study of problems including entropy changes of reversible and irreversible process, entropy changes of mixing process of ideal gases, entropy changes of system and surroundings, and entropy changes of cyclic processes. How to solve the problems of entropy changes has been illustrated by using the related knowledge about the first and second law of thermodynamics, especially the three aspects of knowledge concerning entropy.

A Study on Teaching Method of Homogeneous Reaction Kinetics and Homogeneous Reactor

ZHU Li Ping, LU Zhan Qing, JIANG Chan

2020, 39(6):  50-54. 

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Chemical Reaction Engineering is the core course of chemical engineering and process, and the knowledge of Homogeneous Reaction Kinetics and Homogeneous Reactor is the core knowledge point of chemical reaction engineering. The course aims to train students to establish engineering concepts, which plays an important role in improving the connection between theory and production practice and solving practical industrial problems. The course focuses on the difference between chemical reaction rate and rate of change, the application of BR, PFR and CSTR design equations, and the relationship between molar flow rate and volume flow rate in order to understand the kinetics of homogeneous reactions and homogeneous reactors in chemical reaction engineering, The aim is to improve students' learning and innovation ability, and to provide some reference for the teaching reform of chemical reaction engineering.

Experiment Design of Analog Electronics Circuit Based on NI myDAQ and Multisim

PENG Wenzhu, LIU Yang, WANG Qin, WANG Min

2020, 39(6):  55-60. 

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An experimental design method based on NI myDAQ pocket platform and Multisim Simulation is proposed to solve the problems of analog electronic circuit experiment limited by classroom and traditional instrument. Firstly, students receive the design task requirements through Rain Class, and they use Multisim for project design, parameter estimation, circuit simulation and test. After that, the circuit hardware is built on the bread board, then the circuit is debugged and the fault is analyzed by using NI myDAQ pocket platform. Finally, the simulation results are compared with the hardware circuit parameters to be further adjusted to achieve the optimal circuit design. The results show that the combination of virtual and real teaching mode can effectively improve students' comprehensive circuit design ability and independent innovation ability.

Experimental Simulation of University Server Cluster Load Balancing in Simulator

LI Yong, LI Ping

2020, 39(6):  61-64. 

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The university server cluster task assignment is not balanced, the overall performance is not high, and the real campus network environment is not convenient for the experimental research. Firstly, the working principle of server cluster load balancing technology and network address translation technology are introduced. Then, the experimental case is designed and simulated in the GNS3 simulator, and the detailed experimental design and implementation process are given. Finally, the verification test proves the feasibility of the scheme, overcomes the disadvantage of inconvenient experimental teaching and practice research under the real campus network environment, and deepens the understanding and application of server cluster load balancing technology and network address translation technology.

Dynamic Scheduling Strategy for RGV with Minimum Basic Action Period

SHI Meiling, CUI Qinghong

2020, 39(6):  65-73. 

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A dynamic scheduling model of RGV with minimum basic action period is proposed for the two key problems of real-time scheduling and fault scheduling of RGV based on a detailed analysis of the working principle of linear RGV. The RGV scheduling strategy of this model is to let the RGV select the CNC with the minimum basic action cycle time for service in each scheduling. The basic action cycle time of the RGV is the sum of waiting, motion, loading and unloading, and cleaning time for a CNC that processes the first process in a one-step process or a multi-step process without clinker. For a CNC that processes the first process in a two-process process with clinker, the basic action cycle time of the RGV is the sum of wait, motion, loading and unloading, motion, loading and unloading, and cleaning time. The RGV scheduling model is simulated and solved by matlab programming, and the solution results show that this RGV dynamic scheduling strategy can effectively improve the efficiency of the RGV vehicle.

Exploration on Cultivation of Innovative and Entrepreneurial Talents Majoring in Application-oriented Computer

WANG Wenhao, CHEN Xiaobing, ZHANG Xin

2020, 39(6):  74-78. 

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The school-enterprise cooperation model for the cultivation of application-oriented computer innovative and entrepreneurial talents is studied in this paper aiming at the problems in this field. A new idea for the cultivation of innovative talents is proposed based on the establishment of curriculum system, the construction of practical teaching content and system, the reform of teaching methods and assessment methods, the combination with discipline competition and innovation and entrepreneurship projects, and the integration of innovation and entrepreneurship education into professional education. The cultivation of college students' innovative spirit, entrepreneurial awareness, innovation and entrepreneurship ability, and the promotion of the development of innovation and entrepreneurship education can be realized as well.

Research and Practice of Teaching Mode Based on OBE under New Engineering Background ——A Case Study of C Language Programming Course

YANG Yang, WU Qilin, XU Qiuyue

2020, 39(6):  79-84. 

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The OBE-based teaching model is proposed by analyzing the current situation and existing problems of traditional teaching models in order to cultivate talents to meet the needs of new engineering. The final goal for the cultivation of the students is desigend reversely and immersed into different teaching links. The model is discussed from the aspects of clarifying teaching achievements, adopting multiple teaching methods, and optimizing teaching assessment and evaluation. A case study of the C language programming course is to prove the practical effect.

Analysis of the Difference of County Economic Development and Spatial Correlation Pattern in Jinsha River Basin

HE Jiahui, WU Yingmei, JIAO Min

2020, 39(6):  85-91. 

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County economy is an important part of national economy. Based on the county area as the research scale, real GDP per capita is selected as the research variable, and the difference of county economic development and spatial correlation pattern in Jinsha River Basin from 2009 to 2018 are analyzed by mathematical statistics and spatial analysis. During the research period, the per capita GDP of the Jinsha River basin is increasing year by year, and there are differences at the level of county economic development. The gap between the highest level of development and the lowest is widening and the overall gap is narrowing. The spatial pattern of economic development level is relatively stable, the high value area is mainly located in Kunming City, Panzhihua City and other counties under the jurisdiction, and the low value area is mainly located in Zhaotong City, Ganzi Prefecture and other counties under the jurisdiction. The level of economic development is positively correlated with space, the spatial agglomeration is increasing, and the hot spot area of economic development level is expanding to spots.

Risk Transmission of Financial Derivatives in the Subprime Mortgage Crisis

HOU Jianxiang

2020, 39(6):  92-97. 

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The financial crisis caused by the U.S. subprime mortgage market has evolved into a global financial storm in a short period. The financial crisis is undoubtedly the result of the interaction of financial regulation, excessive financial innovation and other problems. Based on the risk transmission mechanism of financial derivatives in the subprime mortgage crisis, this study discusses a series of problems caused by the complexity of the subprime mortgage product chain and mortgage securitization. Some proposals to the development of Chinese financial derivatives market are put forward as well.

A Study of the Inner Mechanism of Land Resource Mismatch and the Lagging Development of Population Urbanization in China

SUN Liping, YANG Yun

2020, 39(6):  98-104. 

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The puzzle of population urbanization lag is revaled from the perspective of land resource mismatch. The empirical analysis has shown that the land resource mismatch has significant positive impact on population urbanization lag which has a significant impact on the impact of land resource mismatch according to the impulse response function and the effect is more lasting; and that the contribution rate of land resource mismatch to population urbanization lag reaches 50% according to variance decomposition. The study has such positive significance for policy-making as the mismatch of land resources has occupied the resources of service industry, pushed up urban housing prices, and hindered the process of population urbanization in China with the trend of service-oriented economic structure in China; the government should gradually relax the control of land transfer, reverse the mismatch of land resources, and play the basic role of the market in resource allocation.

Research on the Cultivation of Sports Reserve Talents under the Integration of Sports and Education

SUN Hunfeng, SHI Yong

2020, 39(6):  105-110. 

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The development of the integration of sports reserve talents was summarized by the adoption of literature and historical research methods. The pattern of training athletes separately by sports departments has been formed in the phase of combination of sports and education. The situation that education departments lead sports departments to guide the implementation of school organization has emerged in the phase of combination of education and sports. The results showed that the contradiction between learning and training in the combined stage of physical education and education has not been effectively solved, and the number of outstanding athletes trained in the combined stage of physical education and education was limited. The training of reserve competitive talents should set up the ideological fusion of the participation of the whole people under the concept of full-fledged sports, establish the goal fusion of sports personnel under the principle of the comprehensive development of young people, and construct the measures fusion of the new national system including the training of sports teachers, the construction of sports curriculum system, and the design of sports events system.

Probe into the Ways of Carrying on the Traditional Sports of Yi People in Chuxiong

YANG Jianmei, XU Yongqian

2020, 39(6):  111-116. 

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The inheritance path of Yi traditional sports on campus in Chuxiong is analyzed by using the methods of literature, investigation and statistics based on the theory of cultural hierarchy of anthropology. The research finds that the effective ways to carry forward the traditional sports of the Yi people in Chuxiong include focusing on the theme of Yi People culture and reflecting the cultural life of the school, absorbing the cultural nutrients of the times and preserving the basic spirit of Yi People, following the ways of school transmission; deducing the school behavior pattern, adapting the school development rhythm, strengthening the system contract nature, surmounting the appliance use value, and endowing with the cultural symbol significance. The main innovative work of carrying on the traditional sports of the Yi people in Chuxiong should focus on the theme of Yi People culture and protect the basic spirit of Yi people.

Interpretation of the Healthy and Nourishing Value of Yi People's Left-foot Dance in Yunnan

YANG Wenjie, DING Youpeng

2020, 39(6):  117-120. 

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Yi people's traditional left-foot dance in Yunnan is interpreted from the perspective of health and nutrition to conclude that the Yi people's left-foot dance reflects the worship and passion of the Yi people towards their ancestors and fire, and their attitude towards life is restrained and healthy. The dance has the value of keeping fit, promoting body recovery, relaxing and consoling psychology, promoting people's moral health, and constructing healthy ecological culture system. The development mode of minority sports tourism suitable for the development of left-foot dance should be actively constructed from the perspective of health care.

Research on University Library's Participation in Urban Cultural Construction under the Background of National Reading

JIN Guoyan

2020, 39(6):  121-124. 

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In the era of nationwide reading, the service concept and management ideology of university library have changed and the university's participation in the urban cultural development is the requirement for the era, which is also to improve library's service and citizens' cultural quality. The mature social service mode, powerful national policy support, and the library's own advantage provide favorable conditions for the social service of the library. Therefore, the university library's participating in urban cultural construction under the background of nationwide reading can be achieved through establishing effective organization and fund guarantee system; establishing guarantee system for the quantity and diversity of library collection resources; developing customized service for users; and striving for the support of social forces and building a city of readers.

Research on the Realization Path of Collaborative Embedded Service in University Libraries for Makers

HAN Li, LIANG Aidong, ZHAO Lihua

2020, 39(6):  125-128. 

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Promoting the transformation and innovative development of library services by developing a new service mode for makers and integrating into the process of creators' activities in university libraries is an inevitable trend to meet the demand of “double first-class” construction of universities. The collaborative embedded service of university libraries for creators in terms of the establishment of the management system of maker service, the establishment of professional maker service team, the creation of integrated maker service platform, the development of information literacy education for makers, and the strengthening of publicity and promotion of maker service is discussed based on the analysis of the advantages of the collaborative embedded service of university libraries for makers.