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Table of Content
25 May 2019, Volume 21 Issue 3
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    2019, 21(3):  0. 
    Abstract ( 266 )   PDF (317KB) ( 269 )   Save
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    Analysis and Evaluation of Heavy Metal Pollution in Surface Sediments of Chaohu Small Basin
    SHAN Yu, CHEN Jun, WU Ke, JIN Jie, SONG Yong-lian
    2019, 21(3):  1-6.  doi:10.12152/j.issn.1672-2868.2019.03.001
    Abstract ( 905 )   PDF (876KB) ( 303 )   Save
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    In view of the problem of heavy metals in river sediments, the contents and spatial distribution of organic matter, total nitrogen, total phosphorus and six heavy metals (Cr, Ni, Cu, As, Cd, Pb) in surface sediments were analyzed, which were acquired from Chaohu small basin. The sources of heavy metals were analyzed by the method of heavy metal enrichment coefficient and principal component analysis, and the ground accumulation index and potential were utilized. The ecological risk of heavy metals was evaluated by ecological hazard index. The results showed that the average contents of organic matter, total nitrogen and total phosphorus in surface sediments were 162 g·kg-1, 3707.2 mg·kg-1, 2007.4 mg·kg-1.The average contents of Cr, Ni, Cu, As, Cd and Pb were 51.66, 22.97, 36.41, 7.68, 0.40, 33.14 mg·kg-1, respectively. The contents of Cu, Cd and Pb were 1.73, 6.01 and 1.26 times higher than the background values of surface soil in Anhui Province. Cu, Cd, Pb in the sediments have varying degrees of enrichment, and they are closely related to human activities. The degree of Cd pollution in sediments is high, and the potential risk grade of heavy metals is medium, but the overall environmental pollution is mild.
    Design of Chaohu Water Quality Monitoring System Based on ZigBee Technology
    QIAO Xin, KONG Bing
    2019, 21(3):  7-13.  doi:10.12152/j.issn.1672-2868.2019.03.002
    Abstract ( 721 )   PDF (1426KB) ( 331 )   Save
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    Abstract:In order to solve the problems of poor real-time performance, low efficiency and high cost of traditional water quality monitoring methods in Chaohu, a water quality monitoring system is designed based on ZigBee technology. Firstly, the paper analyzes the important factors of current water pollution in Chaohu; the characteristics of water quality, such as pH value, temperature and dissolved oxygen are established, and the overall structure of the monitoring system is given. Secondly, according to the characteristics of the parameters, the corresponding signal conditioning circuit is designed, and the formula for calculating the characteristic parameters is derived.Finally, according to the function of various nodes, the software flow based on the ZigBee protocol stack is designed,and the experiment is carried out by means of the way of carrying the nodes. The experimental results show that the method of wireless sensor network has low cost and high reliability, and can meet the application requirements of
    water quality monitoring.
    Urbanization, Human Capital and Foreign Trade ——An Empirical Study Based on var Model
    XU Xin, YANG Yang, WU Qiu-yue, LI Xiao, SHI Yue
    2019, 21(3):  14-22.  doi:10.12152/j.issn.1672-2868.2019.03.003
    Abstract ( 803 )   PDF (1642KB) ( 303 )   Save
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    Abstract: Since the reform and opening up policy, China has made remarkable achievements in many fields.China爷s foreign trade has also followed the trend of development, gaining more and more discourse power. In this paper, Anhui province was selected as the research object. Firstly, the current situation and existing problems about Anhui province爷s foreign trade are analyzed. Then, based on the time series data in 1981—2015 of Anhui province,we construct var model to analyze the influence of human capital and urbanization on foreign trade. According to the impulse response function variance decomposition model, the results show that urbanization has a deeper impact on foreign trade than human capital. The positive impact on urbanization is good for the development of export  trade. But for import trade, the human capital and urbanization play an unimportant role. Finally, according to the result of empirical analysis, in order to improve the level of foreign trade, the government should increase
    investment in education, improve urban infrastructure construction and urban employment opportunities.
    Bayes Estimation of Reliability of Two-Component Cold Standby System
    LI Ling, BAO Zhi-hui
    2019, 21(3):  23-27.  doi:10.12152/j.issn.1672-2868.2019.03.004
    Abstract ( 633 )   PDF (533KB) ( 283 )   Save
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    Abstract: Bayes estimation of reliability of two-component cold standby system is given. On this basis, we discuss the Bayes hypothesis and Jeffreys priori for the non-informative priori distribution of hyper-parameters, then the multi-layer Bayes estimation of the system reliability is given. The accuracy of multi-layer Bayes estimation under the two kinds of hyper-parametric prior distributions is compared by the example. We also compare the accuracy of Bayes estimation and multi -layer Bayes estimation. Finally, the rationality of multi -layer Bayes estimation is explained.
    Grey Multi-attribute Risk Decision-Making Method and Its Application
    ZHANG Jin-bo, SHI Ming-hua, LI Xiao-ran
    2019, 21(3):  28-33.  doi:10.12152/j.issn.1672-2868.2019.03.005
    Abstract ( 778 )   PDF (634KB) ( 278 )   Save
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    Abstract: In order to solve the problem of grey multi-criteria risk decision -making, a grey random variable ordering method based on expectation theory is presented. This method can reduce the loss of decision making information and improve the decision accuracy. On this basis, this paper gives a method to solve the grey multicriteria risk decision-making problems, where the criteria weights are completely unknown and the criteria values of alternatives are in the form of grey stochastic variables. In this approach, the complementary judgment matrix is obtained by using the proposed ordering method. Through the solution of the non-linear programming model, which is constructed by using the fuzzy complementary matrix method, the order of the alternatives is obtained. The feasibility and validity of this approach are illustrated by an example.
    Boundedness of Commutators of Littlewood-Paley Operators S on Weighted Herz-Hardy Spaces
    XIAO Dan, XIE Ru-Long
    2019, 21(3):  34-39.  doi:10.12152/j.issn.1672-2868.2019.03.006
    Abstract ( 732 )   PDF (590KB) ( 290 )   Save
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    Abstract: In this paper, some properties are considered for the commutators of Littewood-Paley operators S on weighted Herz-Hardy spaces. It discusses the boundedness of S from HK  to K  and from HK to WK.  
    Key Frame Selection and Mosaic of High Resolution UAV Panoramic Images of Construction Sites
    SUN Guang-ling, ZHU Qing-sheng, LI Qian-ru
    2019, 21(3):  40-46.  doi:10.12152/j.issn.1672-2868.2019.03.007
    Abstract ( 907 )   PDF (2730KB) ( 282 )   Save
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    Abstract: As the scale of construction sites increases, it's becoming more and more difficult to understand the status of construction sites timely. Thanks to the development of Unmanned Aerial Vehicle technology, a large number of image data of construction sites can be collected in a short time. Utilizing these data, large-scale construction sites can be monitored effectively using computer vision technology in real time. In this paper, a method of image stitching for panorama of construction site is proposed, which adopts the strategy of filtering fuzzy frame, selecting key frame and correcting camera lens distortion. This method produces a complete panorama of high quality, which helps to identify various construction site environments in the context of high-quality image data.
    Design of 12-Port MIMO Antenna for 5G Communication in Mobile Handset
    CHENG Bi-yu, JI Ming
    2019, 21(3):  47-55.  doi:10.12152/j.issn.1672-2868.2019.03.008
    Abstract ( 1131 )   PDF (6120KB) ( 474 )   Save
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    Abstract: A compact 12-port MIMO antenna system is proposed. This system consists of eight stereoscopic inverted F antenna and four inverted F antenna : The 1—4# antenna element and 5—8# antenna element are mainly used for 5G communication and the impedance bandwidth can cover 3300~3600 MHz. The 9—12# antenna element is a supplement to mainly cover the 5G communication spectrum of 4800~5000 MHz. The isolations of the low band and high band of this MIMO antenna system are higher than 12 dB and 19 dB respectively. Moreover, this system has higher gain and radiation efficiency at low band and high band.
    Construction of Emergency Handover Management System for Business Support
    SHAO Gui-wei, WANG Min-qiu, LI lei
    2019, 21(3):  56-63.  doi:10.12152/j.issn.1672-2868.2019.03.009
    Abstract ( 617 )   PDF (3228KB) ( 245 )   Save
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    Abstract: Most business support systems are equipped with emergency management system to handle system failure. But the traditional emergency system has the weakness of time lag, so the development of practical emergency system is essential. On the basis of expounding the present situation of the service system and analyzing the necessity of emergency handover management, the emergency handover management system is put forward, and then the function and the key technology of emergency handover management system are described in detail.Combining with the experimental data, the performance of the system is analyzed. The emergency handover management system innovatively realizes the automatic detection and alarm, automatic switching to emergency system, and performance trend forecast and warning. Meanwhile, the implementation cost of the system is low,which can effectively shorten the switch time, reduce or eliminate the negative effects due to system failure.
    Hot Topics and Trend Analysis of Tropical Cyclone Research Based on Knowledge Map
    JIANG Hao, LI Jun-li, GAN Rui-jie, WU Wen-jun, ZHANG Jie
    2019, 21(3):  64-77.  doi:10.12152/j.issn.1672-2868.2019.03.010
    Abstract ( 452 )   PDF (4091KB) ( 351 )   Save
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    Abstract: The hazards triggered by tropical cyclones have become a well-known global problem. To reflect the research progress of tropical cyclones, based on 22,678 articles related to tropical cyclones published in SCIE and SSCI databases from 1991 to 2017, we analyzed the literature production, state and organization, keywords and core authors of tropical cyclones by using the knowledge map and Bibliometric analysis. The results show that the quantity of tropical cyclones has been increasing, and the increase is obvious after 2006. The cooperation between countries is centered on the United States, and the trend of cooperation presents regional relevance. The United States is an important node in the network of tropical cyclone collaborators. The National Oceanic and Atmospheric Administration of the United States has the largest number of publications, and the Chinese Academy of Sciences and the National Taiwan University are among the ten leading institutions. The three magazines that published the most articles related to tropical cyclones are Monthly Weather Review, Journal of the Atmospheric Sciences and Geophysical Research Letters. Montgomery Michael T is the most published author. Typhoons and hurricanes are the most important keywords in tropical cyclones research. Sea level rise, resilience, community and health, disaster, climate change and remote sensing are the hot topics in recent years in the field of tropical cyclone research. The number of articles with keywords related to social media and Twitter has been increasing in recent years.
    Screening and Identification of Mycorrhizal Fungi against Fusarium oxysporum
    ZHANG Yan, YUAN Quan, LIU Li-li, FANG Ming-ming, XU De-cong
    2019, 21(3):  78-88.  doi:10.12152/j.issn.1672-2868.2019.03.011
    Abstract ( 556 )   PDF (2800KB) ( 360 )   Save
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    Abstract: Fusarium oxysporum is the pathogen of blueberry root rot. The symbiotic mycorrhizal fungi of blueberry root play a role in the growth and development of blueberry and can antagonize harmful microorganisms. In this study, mycorrhizal fungi were isolated from blueberry roots in different areas of Anhui Province. The strains antagonistic to Fusarium oxysporum were screened by bacteriostatic experiment to explore the biological characteristics of antagonistic bacteria and optimize the culture conditions. The results showed that the root infection of blueberry was quite different in different areas of Anhui province. A total of 17 strains of endophytic mycorrhizal fungi were isolated, of which 6 strains were mycorrhizal fungi with antagonistic effect of Fusarium oxysporum.Trichoderma spinosum Hfsu02 had the best antagonistic effect. Under the condition of shaking flask culture in basic
    culture medium, the optimum growth temperature was 25益, the optimum pH was 4, the logarithmic growth period was 12 ~112 h, and the highest yield of dry weight of mycelium was 2.76 g/L. The screening and culture optimization of Trichoderma spinosum Hfsu02 provide theoretical basis for the control of blueberry root rot, and have important guiding significance in the biological control of blueberry root rot.
    Research on Low Voltage Ride Through of Wind Turbine Based on Energy Dissipation Crowbar Circuit
    NIU Jin-cai, WANG Zheng-chuang, TANG Rui-hua, DING Wei-min
    2019, 21(3):  89-92.  doi:10.12152/j.issn.1672-2868.2019.03.012
    Abstract ( 518 )   PDF (1196KB) ( 320 )   Save
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    Abstract: Low voltage ride through capability of wind turbine is a necessary condition for large-scale grid connected operation. It is the guarantee that the wind turbine has the capability of continuous operation. In this paper, the energy dissipation Crowbar circuit is used to study the low voltage ride through capacity of wind turbine, and the simulation analysis is carried out by using the MATLAB/Simulink toolbox. The simulation results show that the energy-dissipating Crowbar circuit can effectively protect the over-voltage of DC-link and realize the requirement of LVRT. The scheme has simple circuit topology and high reliability.
    Design and Implementation of Hardware-in-the-loop Simulation Test Platform for UAV Flight Control System
    LU Wen-jun
    2019, 21(3):  93-101.  doi:10.12152/j.issn.1672-2868.2019.03.013
    Abstract ( 512 )   PDF (1465KB) ( 371 )   Save
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    Flight control system is the integrated command center and core component of UAV system. Aiming at the problem of poor accuracy and low efficiency in field measurement of parameters of flight control system, combined with the configuration of flight attitude angle sensor-vertical gyroscope, hardware-in-the-loop simulation technology and integrated automatic test method are adopted. The hardware-in-the-loop simulation test platform of UAV flight control system is composed of a miniaturized UAV attitude calibration platform with low cost and high precision and test device of controlpiston deflexion angle is designed. The main controller is used instead of the main ground control station of UAV to send remote control instructions directly to the aircraft. By changing the attitude of the aircraft, the voltage of control signal, feedback signal and rudder angle are measured, and the comprehensive performance test of flight control system parameters is realized. The performance test of the platform shows that it can meet the test requirements of angle position, system voltage and controlpiston deflexion angle.
    Obstacles to China's Sports Policy Implementation and Countermeasures
    LI Xia
    2019, 21(3):  102-108.  doi:10.12152/j.issn.1672-2868.2019.03.014
    Abstract ( 451 )   PDF (1025KB) ( 366 )   Save
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    Abstract: Based on a comprehensive analysis of obstacles to our sports policy implementation in the social transitional period, this article holds that the main factors, such as executive subjects, executive objects, executive systems and executive conditions, influence the implementation of sports policy. The following countermeasures are put forward to implement our sports policies successfully: optimizing sports policy executive subjects, strengthening integration of relevant interests and enhancing construction of sports executive systems and environment.
    Effects of Different Carbohydrate Mixtures Supplementation on Glycogen Synthesis after Exercise
    LI Fang-fei
    2019, 21(3):  109-113.  doi:10.12152/j.issn.1672-2868.2019.03.015
    Abstract ( 453 )   PDF (1166KB) ( 365 )   Save
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    Abstract: Objective To investigate the effects of different carbohydrate mixtures on glycogen synthesis after exercise. Methods Twenty-four college long-distance runners participated in the study and were randomly divided into three groups: group A; group B and group C. The body composition and diet of the subjects were evaluated before the experiment. Blood samples were taken after oral administration of a 1 g/kg body weight mixture before and after exercise. The mixture was a maltodextrin-glucose-fructose mixture (MGF), a maltodextrin-glucose (MG) mixture and a placebo (P). Group A received oral MGF; Group B received oral MG; Group C received oral placebo.Results After ingestion of the mixture after exercise, the plasma glucose levels in group A and group B increased similarly during the recovery period of 30 min. Plasma glucose levels remained unchanged in group C during the recovery period. During the recovery period, the areas under the curve of Group A and Group B were higher. Compared with group C, plasma FFA levels were lower in group A and group B, and the change in recovery period was smaller (P<0.05). Conclusion Supplemental MG produces different postprandial blood glucose patterns for 60 min and 90 min of exercise. Supplementation of MGF and MG was similar in response to FFA production after exercise.In addition, early in MGF supplementation, plasma glucose levels were reduced, but this did not happen in MG supplementation.
    Exploration on the Cultivation of International Vision for Science and Engineering College Students in the Context of "Community of Human Destiny"
    JIAO De-gang, FENG Juan
    2019, 21(3):  114-118.  doi:10.12152/j.issn.1672-2868.2019.03.016
    Abstract ( 700 )   PDF (952KB) ( 432 )   Save
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    With the rapid development of economy, science and technology, China is gradually moving towards a strong industrial country. Science and engineering education gradually gets mature, and the scale of science and engineering personnel training is also growing. The concept of community of human destiny provides a historic opportunity for the development of international education and the cultivation of talents with international vision in colleges and universities. It is one of the important tasks for colleges and universities to strengthen the analysis of the current situation of the cultivation of talents with international vision for science and engineering majors, to face the problems in the cultivation of talents with international vision, and to explore the path of expanding the cultivation of students忆international vision. It should meet the objective needs and inevitable choices of the development of the times and the practice of the community of human destiny.
    Research on Training System for Artificial Intelligence Talents against the Background of New Engineering
    YAN Yuan-ting, ZHANG Yi-wen, CHEN Jie, ZHANG Yan-ping
    2019, 21(3):  119-125.  doi:10.12152/j.issn.1672-2868.2019.03.017
    Abstract ( 1190 )   PDF (1134KB) ( 454 )   Save
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    China is now in a critical period of economic transition, innovative talents with innovative spirit and ability are the core supporting force to promote social and economic transition. Advanced technologies with artificial intelligence as the representative are playing an increasingly important role in the new economy. The "new engineering" project which aims to cultivate innovative talents has become a consensus of engineering education circle of China. In artificial intelligence (AI) innovation action plan, Ministry of Education states that the construction of new engineering project should be promoted and the AI talent training system be improved. Against this background,this paper first analyzes the characteristics of artificial intelligence and the experience of famous foreign universities, and then discusses the construction ideas for AI talent training system from three aspects, including the formulation of flexible training program for AI talent, the construction of curriculum system for AI talent training, and the design of bachelor-master-doctoral talent training path.
    Construction of Engineering Training Teaching Model for Materials Majors in Applied Universities Based on Product Orientation
    XIE Jin-song, HUANG Jun-jun, ZHAO Di-fang, LIU Jian-zhong, DONG Qiang
    2019, 21(3):  126-131.  doi:10.12152/j.issn.1672-2868.2019.03.018
    Abstract ( 530 )   PDF (971KB) ( 310 )   Save
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    At present, with the background of Intelligent Manufacturing, Industrial 4.0 and New Engineering, student training in engineering colleges and universities is faced with the difficult problem of how to cultivate students' practical and innovative abilities through practical teaching. Based on this, this paper explores a new practical teaching mode of multi-disciplinary collaborative engineering training for Materials majors based on product orientation. That is, starting from serving regional industries, through in-depth investigation of enterprises, judging the needs of enterprises, establishing specific products as the research object, decomposing their production process,carrying out engineering training for different majors according to their professional characteristics, and finally realizing the whole training objective. Firstly, taking Material Science and Engineering Major of a college in Anhui as an example, the concrete implementation steps and contents of this engineering training teaching are elaborated in detail. This paper comprehensively expounds the characteristics of this training mode from three aspects: improving the teaching and scientific research level of university teachers, improving students' comprehensive ability and implementing the application-oriented teaching objectives. This paper puts forward some suggestions on the construction of engineering training platform based on multi-disciplinary collaborative teaching and the development of collaborative teaching content. This will provide reference for the optimization, promotion and continuous improvement of talent training quality in applied engineering colleges and universities.
    An Empirical Study on the Effects of Project-based Teaching in Universities—Taking the Project-based Teaching of "Mechanical Engineering Materials and Forming Technology" as an Example
    ZHOU Ming-jian, WANG Yu-qin
    2019, 21(3):  132-139.  doi:10.12152/j.issn.1672-2868.2019.03.019
    Abstract ( 526 )   PDF (1074KB) ( 317 )   Save
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    Abstract: Taking the project-based teaching of "Mechanical Engineering Materials and Forming Technology" as an example, this study combines quantitative evaluation with experimental research to analyze the questions of "projectbased teaching effect" and "students忆adaptability to project-based teaching", and verifies the rationality of the experimental results by evaluating studentsattitude and acceptance to university project-based teaching through questionnaire survey. The results showed that the overall performance of students with project-based teaching was significantly higher than that of students with traditional teaching, and students with high learning motivation and ability improved more significantly. Project-based teaching has obvious advantages over traditional teaching mode in helping students achieve good grades, while the overall improvement of students with low learning motivation and learning ability is lower than that of students with traditional teaching. In order to achieve good teaching effect, on the basis of analyzing the characteristics of teaching objects, project-based teaching should carefully select teaching resources, compile teaching content, design teaching process, teach students in accordance with their aptitude, stimulate students' learning motivation, and improve their learning ability in the process of completing the project.
    An Empirical Research on Blended Teaching Based on Mobile Phone Interaction ——Taking "Probability Theory and Mathematical Statistics" as an Example
    MA Yong-mei, HU Chuan-shuang
    2019, 21(3):  140-148.  doi:10.12152/j.issn.1672-2868.2019.03.020
    Abstract ( 581 )   PDF (2737KB) ( 290 )   Save
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    Taking the course of probability theory and mathematical statistics as the practical teaching content, the mixed teaching was carried out with the mobile phone interactive teaching software—-Moso teach, and the comparison analysis was made between the data collected from the mobile end of the Moso teach and the traditional teaching effect. The results show that information-based teaching not only changes students' learning environment and learning behavior, but also changes teachers' teaching mode and makes the educational concept constantly updated.From the perspective of teaching effect, information-based teaching resources are more convenient to obtain and mobile phone interaction not only stimulates students' interest in learning, improves their academic performance,but also objectively evaluates students' learning situation. Mixed teaching mode with mobile learning can better integrate the advantages of online and offline teaching, optimize teachers' teaching and students' learning, and play an active role in teaching reform. Finally, combined with practical teaching experience, some suggestions are given.
    The Effect of Flipped Classroom on Students' Satisfaction and Academic Achievement—A Case Study of Sports Anatomy
    WANG Cheng-ji
    2019, 21(3):  149-156.  doi:10.12152/j.issn.1672-2868.2019.03.021
    Abstract ( 477 )   PDF (1122KB) ( 276 )   Save
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    The purpose of this study was to examine the satisfaction of sports anatomy students in flipped learning and to analyze their academic achievement in comparison with lecture class. The subjects were 40 students who participated in flipped learning during sports anatomy course in the first year. After performing flipped learning,formative assessment was conducted and the degree of satisfaction was examined. Questionnaires of satisfaction were developed to identify the perceptions of students on flipped learning. To compare the academic achievement of students, formative assessments were conducted at the end of the flipped learning class and the lecture class. The data was analyzed by frequency and paired t-test method. The students showed a high level of frequency in using lecture notes (80.6%)and lecture slides (74.2%)among the pre-class learning resources. The average score (3.89)was higher for the factor of interaction and collaboration in the classroom than for the factor of improving learning (3.62). The average score of the students in the formative assessment was 4.28 points (out of 10 points)in the lecture class, while it was 5.56 points (out of 10 points)in the flipped learning class, thus showing a statistically significant difference (t=-4.203, p<0.001). It was observed from the reaction of the students that flipped learning is helpful for the interaction and collaboration in the classroom. It is expected that this result will be useful as basic data for sports anatomy course to try flipped learning in the future.
    The Application of Independent Experiment Teaching in Econometric Teaching Based on EViews
    WANG Shu-chao, MU Lan
    2019, 21(3):  157-164.  doi:10.12152/j.issn.1672-2868.2019.03.022
    Abstract ( 643 )   PDF (2474KB) ( 401 )   Save
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    Econometrics is a very practical subject. Ignoring the practice would make learning of the theory especially boring, and it is not conducive to the cultivation of students忆practical ability. The previous experimental teaching was mainly demonstrated by teachers, it usually led to students' lack of thinking, so they cannot solve different problems flexibly. The independent experimental teaching based on EViews gives students plenty of room to think. On this basis, the teachers evaluate the experimental contents of the students and then guide them to perfect the experimental project. This can help students to develop the ability to solve practical problems.