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Table of Content

    15 June 2021, Volume 6 Issue 6
    Convergence xn + 1 = f ( xn ) of Sequence Determined by Monotonic Function y = f ( x )
    Zhang Youmei, Wu Bangkun
    2021, 6(6):  1-4.  DOI: 10. 3969 / j. issn. 2096-2266. 2021. 06. 001
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    This article takes a type of recursive sequence xn + 1 = f (xn ),n = 0,1,2,⋯, determined by a function y = f(x)as the research object. Assuming that f(x)is monotonic, and in the absence of a general term formula, the method for judging the convergence and divergence of the sequence of {xn} is proposed, and the general law of the judgment method is summarized. Finally, specific applications are given to verify the effectiveness and feasibility of the method.
    Study on Insect Community Network Structure and Self-Adaptation in Erhai Lake Wetland
    Hao Hongjun, Wang Xi, Zhang Mei, Liu Xuan, ZhuYuanbo, Luo Guilan
    2021, 6(6):  5-14. 
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    In order to research the self-adaptation of insect communities to their habitats in the Erhai Lake wetland, the character
    index of the insect community structure was studied. With the help of complex networks, the insect ecological network model was
    established and optimized, and the composition of insect communities in wetlands in different regions was analyzed. It was found that
    changes in the regional ecological environment by human activities directly affect the changes of dominant insect groups. Besides, the
    temporal evolution of insect community structure was analyzed. Results show that the structures of three insect communities in Erhai
    Lake wetland are similar to each other, and a strong stability exists in the original wetland. Modified wetlands have certain selfregulation ability, and seasonal habitat changes are crucial factors influencing the variety of insect communities. Finally, the correlation analysis of the characteristic parameters of insect community structure shows that species richness and diversity index are important indicators for the maintenance of the stability of insect community structure. Insect communities in Erhai wetland have strong adaptive ability, which indicates that the current ecological environment of Erhai Lake wetland is in a benign development.
    Biomimetic Approach to Self-Cleaning Surfaces of Natural Qingshi Stone
    Duan Zhuoqi, Xie Zaixin, Zhao Zhanqiang, Zhou Bao, Li Ruheng, Zheng Xiaohong, Hu Yongmao
    2021, 6(6):  15-21. 
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    Self-cleaning surfaces have significant applications in the protection of natural stone surfaces. Based on the strong adhesion of polydopamine and the condensation reaction between the Al—OH on the surface of Al2O3 and the —P(O)(OH)2 group of
    alkylphosphoric acid form P—O—Al covalent bond, Qingshi stone was soaked in Tris-HCl solution of dopamine to form the adhesion
    layer on its surface. A layer of fluorinated Al2O3 nanoparticles was constructed on the surface of the Qingshi stone by a soaking in
    absolute ethyl alcohol dispersion contains Al2O3 nanoparticles and fluorophosphonic acid C10(FPA). Water static contact angles bigger than 160° and hysteretic angles smaller than 20° were obtained on the self-cleaning surfaces. The SEM images of as-prepared Qingshi stone surfaces show a micro/nanoscale roughness.
    Preparation and Bandgap Tuning of Nanoscale Cu3SnS4
    Hu Yongmao, Zhao Zhanqiang, Xie Zaixin, Duan Zhuoqi, Zhou Bao, Li Ruheng
    2021, 6(6):  22-28. 
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    As a P-type semiconductor, Cu3SnS4 has significant application value in the fields of gas sensors, dye sensitized solar cells,
    thermoelectric conversion and so forth due to its high hole concentration, high light absorption coefficient and wide range of bandgap.
    However, due to its structural diversity and wide bandgap value range, it needs to be optimized and tuned according to actual use. This article reviews the preparation and bandgap tuning methods of nanoscale Cu3SnS4 in recent years, summarizes the preparation methods of nanoscale films and powders, such as magnetron sputtering, solvothermal, ball milling and other processes, as well as the bandgap tuning methods of crystal structure controlling and doping of nanoscale Cu3SnS4. In the end, the prospect for the research of nanocrystalline Cu3SnS4 is put forward.
    Innovation of Student-Centered Mixed Teaching Mode in Creo Course
    Zhang Yangmei, Hua Haiyan, Yang Shuanqiang, Shen Zhenhui, Huang Xinlong
    2021, 6(6):  29-33. 
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    As the engineering changes the world, the technology creates the future as well. Students trained in the new engineering
    background must have solid basic skills and excellent innovation ability. Aiming at the difficulties in cultivating students' design
    innovation ability, poor self-discipline, and weak basic knowledge in Creo course teaching, a "student-centered(SC)" mixed teaching
    mode was carried out. Through the mix of class teaching, group discussion, online and offline, theory and practice, the initiative of
    students in learning has been promoted and the quality of courses has been improved.

    Study on Preparation and Visible Light Photocatalytic Activity of Fe3+ Doped AgInS2
    Ba Deyan, Yang Ni, Yan Ya
    2021, 6(6):  34-39. 
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    Objective: To study the effects of Fe3+ doping on the structure, morphology and visible light photocatalytic activity of AgInS2. Methods: AgInS2 doped with different amount of Fe3+(denoted as Fe-AgInS2)were prepared by in-situ liquid phase method. Rhodamine B(RhB)and p-nitrophenol(PNP)were used as the degradation substrates for studying the visible light photocatalytic activity of Fe-AgInS2. Results: When Fe3+ : In3+ = 2.8 : 14.2, Fe-AgInS2 has the highest visible light catalytic activity for the degradation of RhB; among the four samples, Fe-AgInS2 with Fe3+ : In3+=12 : 5 has the highest visible light catalytic activity for the degradation of PNP. Conclusion: The doping of Fe3+ into AgInS2 did not change the structure and morphology of AgInS2, but it could adjust the particle size and crystallinity, enhance the absorption of AgInS2 in the range of 450-600 nm, and inhibit the recombination of photogenerated electrons(e-)and photogenerated holes(h+), thus improving the visible light photocatalytic activity of AgInS2.
    Study on the Synthesis of Nb2O5 Catalysts and Photocatalytic Selective Oxidation of Cyclohexane
    Chen Mei, Luo Jia, He Jieli
    2021, 6(6):  40-44. 
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    Objective: To explore the effect of the morphology of Nb2O5 nanocatalysts on the selective oxidation performance of
    cyclohexane under visible light irradiation, and to establish an efficient and environmentally friendly method for the selective oxidation
    of cyclohexane to synthesize cyclohexanone and cyclohexanol. Methods: Controllable synthesis of Nb2O5 nanocatalysts with different
    morphology was achieved by hydrothermal method; 300 W xenon lamp was used as light source(λ > 420 nm); the products were
    analyzed and determined quantitatively by gas chromatography with internal standard. Results: Through controlling the hydrolysis
    condition of NbCl5, and Nb2O5 nano short column, nanorods and nanowires were obtained after hydrothermal treatment. Under the
    optimum reaction condition, the conversion of cyclohexane was 94.7%, and the total selectivity of cyclohexanone and cyclohexanol was
    69.2%, respectively. Conclusion: The selective oxidation of cyclohexane catalyzed by Nb2O5 nanocatalysts under visible light
    irradiation has a significant morphological effect. Over the Nb2O5 nanowires, the photocatalytic selective oxidation of cyclohexane to
    cyclohexanone and cyclohexanol can be efficiently driven under visible light at normal temperature and pressure.
    Study on Detection Method of Related Substances in Norfloxacin Glucose Injection
    Rong Nana, Liu Yi, Liu Jihua, Gui Lihua, Ren Liyue, Li Zhiyuan
    2021, 6(6):  45-49. 
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    Objective: To establish a high performance liquid chromatography method for the detection of related substances in norfloxacin glucose injection. Methods: Chromatographic column is SHISEIDO C18 column(4.6 mm × 250 mm, 5 μm), mobile phase
    A is 0. 02 mol/L phosphoric acid solution(adjusted to pH(3.0 ± 0.1)by triethylamine)-acetonitrile(90:10), and mobile phase B is acetonitrile, with gradient elution in different proportions. Flow rate: 1.0 mL/min; detection wavelength: 278 nm; column temperature:40 ℃; injection volume: 20 μL. The peak area of norfloxacin was used to calculate the content of related substances according to the external standard method. Results: The main component peaks in norfloxacin glucose injection and the peaks of each degradation product can be separated well. Impurity A, E, and H were not detected in 15 batches of samples. The content of impurity K was 0.05%.The average content of single maximum impurity was 0.08%-0.10%, and the average content of total impurities was 0.20%. Research of destructive test under acid, alkaline, oxidation and ultraviolet light, proved that the method has good specificity. Conclusion: The established method has good specificity, high sensitivity, and good separation of each peaks. It can be used for the detection of related substances in norfloxacin glucose injection.
    Bioinformatic Analysis of Differentially Expressed Genes in Human Lupus Nephritis Blood
    Cui Daolin, Chen Chunli
    2021, 6(6):  50-54. 
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    Objective: Bioinformatic analysis was used to screen differentially expressed genes in human lupus nephritis(LN)blood,and to identify potential biomarkers of LN and specific drug targets. Methods: The GSE72747 gene set was downloaded from the GEO
    database. Differentially expressed genes were screened and visualized using R 3.6.1 software. GO functional enrichment analysis and
    KEGG signaling pathway analysis were performed using R software. Protein-protein interaction(PPI)networks were constructed using the STRING database. Results: A total of 59 differentially expressed genes were screened. The function was mainly enriched in Fcγ receptor binding and antigen binding. Signaling pathway analysis of differentially expressed genes showed enrichment of AMPK and mTOR signaling pathways. PPI networks derived from differentially expressed genes comprised 30 nodes and 54 interactions.
    Conclusion: Five key differentially expressed genes(EZH2, IGLL5, MS4A1, PAX5, and CD38)in human LN blood were identified as
    potential biomarkers for the early diagnosis of LN and specific targets for potential therapeutic agents.
    Evaluation of Planting under Forest via Sustainable Development: A Case Study on Amomum tsao-ko#br# Planting along Dulong River#br#
    Sun Jun, , Dai Lujiao, , Wang Haohan, Xiong Yun, Huang Zhipang, Xiao Wen, , , Li Yanpeng, ,
    2021, 6(6):  55-59. 
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    In order to evaluate the effects of Amomum tsao-ko planting on forest structure and the distribution pattern of the Trachypithecus shortridgei populations, community interviews and field studies were conducted to systematically investigate the planting areas of Amomum tsao-ko, the present situation of the Amomum tsao-ko planting, the current distribution pattern of the Trachypithecus
    shortridgei populations and the forest structure via community and field investigating in the Trachypithecus shortridgei's habitat. The
    results showed that the Amomum tsao-ko planting area still showed a rapid rising trend; the population distribution of Trachypithecus
    shortridgei was sporadic small groups, the distribution points increased to 45, and the average number of individuals in a single
    population had fallen by 5 individuals; there were significant differences in forest structure between the planting area and the nonplanting area, such as the height of trees in the planting area was significantly higher than that in the non-planting area, the arbor
    canopy connectivity distance was increasing, and the canopy projection surface was decreased. At present, the planting area of Amomum tsao-ko has been increasing speedily, which has affected the forest structure and the distribution pattern of Trachypithecus shortridgei.
    New Records of Two Species of Rhododendron in Cangshan Mountain
    Zhang Zhengquan, Li Jianwei, , Su Hongyan, Li Jihong, He Lü, Su Xijun
    2021, 6(6):  60-61. 
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    Using methods such as field investigation, specimen collection and identification, library specimen and electronic
    specimen search, and literature review, researched the plant resources and distribution of Rhododendron, and two new record species
    were discovered: R. roseatum Hutch. and R. liliiflorum Levl. , and described its morphological characteristics, distribution range, etc.
    Research on the Mechanism and Path of the Symbiotic Development of Sports-Themed Towns and#br# Rural Revitalization in the New Era#br#
    Liu Xiaohu
    2021, 6(6):  62-69. 
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    Based on symbiosis theory, this study uses literature, logical analysis, field investigations and other research methods,
    starting from the four dimensions of symbiosis unit, symbiosis interface, symbiosis model, and symbiosis environment, to explore the
    mechanism of symbiotic development of sports-themed towns and rural revitalization in the new era. A developmental path is proposed,
    that is, to promote the energy generation, to improve the interface, to build an ideal mode, and to optimize the environment for the
    symbiotic development of rural revitalization and sports-themed towns.
    Investigation on How to Integrate Guangxi Minority Traditional Sports into Rural Revitalization
    Feng Zhibo, Wu Guangjin, Huang Fei
    2021, 6(6):  70-76. 
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    Traditional sports of ethnic minorities in Guangxi should become a boost for rural revitalization. Field surveys were carried out on three traditional sports events with distinctive Guangxi characteristics, including dragon-boat race, throwing embroidered ball and grabbing fireworks, and it was found that the integration of traditional minority sports in Guangxi into rural revitalization faces many difficulties and continues to influence the implementation of sports poverty alleviation strategy. Therefore, it is urgent to improve farmers' understanding and concepts of sports, to fully mobilize social resources to participate in ethnic sports development and rural
    revitalization, to continuously innovate traditional ethnic sports into the rural revitalization model, and to promote the coordinated
    development of ethnic regions.
    Experience and Enlightenment of the Development of Surfing in America and Australia
    Wang Lin
    2021, 6(6):  77-83. 
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    Using the method of literature and logical analysis, this paper analyzes the general situation of the development of surfing
    in America and Australia, sums up their experience, and provides some enlightenment for the development of surfing in China, that is, to explore the alliance system of surfing associations, to set a goal in the Olympic games, to build a brand for the surfing team, to perfect the surfing management system, and to cultivate teenagers' enthusiasm for surfing, thus to encourage people's participation in international events, cultivate mass enthusiasm, give full play to the role of national fitness surfing, and promote the all-round one-stop service construction of surf clubs.
    A Study on the Physical Conditions of Primary School Students of Zhiguo Ethnic Groups in Nujiang River Basin#br#
    Zhang Jian
    2021, 6(6):  84-89. 
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    In order to understand the physical differences of the pupils of Zhiguo(directly-entering socialism)ethnic groups in the
    Nujiang River basin, the physiques of the pupils were studied though the investigation method,etc. The results showed that the heights of the pupils were in the order of Han> Lisu> Nu> Dulong; the body weights of the Zhiguo pupils were lower than those of the Han pupils, and the body weights of Nu and Dulong pupils were significant difference with Han pupils(P < 0.05); the vital capacities of the Zhiguo pupils were mostly lower than those of the Han pupils; the overall performance of 50 m was Han< Lisu< Nu< Dulong; in the Sit and Reach, Zhiguo boys generally performed better than Han boys; in the 1-minute sit-ups, the boys performed in the ranks of Nu>Han> Lisu for 9-12-year-old boys; in the 1-minute jumping rope, Nu pupils performed better than Dulong pupils for 7-11-year-old boys, and the difference between Nu pupils and Dulong pupils in most age groups was statistically significant(P < 0.01).
    Status Quo and Influencing Factors of Students' Outdoor Extracurricular Activities in Dali University
    Qi Hengbo, Hou Guoliang
    2021, 6(6):  90-93. 
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    This paper analyzes the status quo of extracurricular outdoor sports in Dali University through questionnaire surveys,
    literature review, interviews and mathematical statistics analyses, and draws the following conclusion: students of non-sports majors at Dali University have insufficient knowledge of extracurricular sports activities and their participation of outdoor sports activities are
    relatively not diverse and frequent enough. Most students prefer mountain-climbing and bicycling, and know little about other
    activities. Through investigation, it is understood that the development of extracurricular outdoor sports is restricted by factors such as
    safety factors, site facilities and teacher resources, etc.
    Prediction of Air Quality Index in Zhaotong City of Yunnan Province Based on a Combined Model
    Zhao Yufeng, He Shuxian, Wang Pengde
    2021, 6(6):  94-100. 
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    Based on the air quality data of Zhaotong City in Yunnan Province in the past three years, this paper establishes multiple
    linear regression, time series, random forest, and regression tree prediction models, and then selects random forest and regression tree models with higher prediction accuracy to construct a combined model of random forest and regression tree, which uses the standard deviation method to determine the weights. Through the prediction and analysis of the air quality of Zhaotong City in August 2020, it is found that the combined model has higher a prediction accuracy and lower error rate than the single model. Therefore, the model can be widely used in air quality prediction.