Table of Content

15 December 2021, Volume 6 Issue 12

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Explicit Formulas of Hosoya Index and Merrifield-Simmons Index of Banana Trees

Yang Limin

2021, 6(12):  1-4. 

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Hosoya index and Merrifield-Simmons index are two important topological parameters in chemical graph theory. Let G1， G2， ...，Gn be a family of disjoint stars， the tree obtained by joining a new vertex to one pendant vertex of each star Gi is called a banana tree. In this paper， by analyzing components in graph theory， the number of all S（n ）-factors of any banana tree is derived， further， explicit formula of Hosoya index of a banana tree is gained. Finally， in a similar vein， explicit formula of Merrifield-Simmons index of a banana tree is presented.

High Average-Utility Co-Location Patterns Mining Algorithm with Rare Features

Zeng Xin, Li Zhenpeng, Yang Jian, Li Xiaowei

2021, 6(12):  5-11. 

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Spatial high utility co-location patterns mining uses the sum of participating utility of all features in pattern as the measurement standard， without considering the impact of pattern length and rare features. In general， the longer the pattern length or the rarer the features， the greater the utility of the pattern. This paper is based on spatial high-utility co-location pattern mining， while considering the pattern length and possible rare features of patterns. Firstly， the definitions of high average-utility co-location pattern mining with rare features is proposed； then， a high average-utility co-location pattern mining algorithm HAUWR with rare features is constructed， and a large number of experiments on HAUWR are performed on real and synthetic data sets. The experiment result shows that algorithm HAUWR can mine the complete set of co-location patterns that meet the conditions， and has good scalability. Finally， regarding the impact of pattern length of high utility co-location patterns， HAUWR is compared with high utility co-location patterns mining algorithm HUWR containing rare features in some aspects， such as dataset size， distance threshold， and feature rarity.

Location Model of Logistics Distribution Center Based on Variation and Dynamic Adaptive PSO

Li Xuan, Wu Xiaobing, Liu Qiong

2021, 6(12):  12-16. 

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Taking into account various influencing factors， this study established a logistics distribution center location model with the least total cost and the best timeliness. A particle swarm optimization with variation and dynamic self-adjustment is proposed to solve the complex practical optimization problem. The parameters in the algorithm are adjusted dynamically and non-linearly. At the same time， the variation mechanism with transplanted genetic algorithm helps the algorithm effectively get rid of the constraints of local optimization. The results show that the particle swarm optimization based on dual mechanism optimization has further improved the algorithm efficiency and optimization ability. The proposed algorithm is applied to the solution of the more complex logistics distribution center location problem， and it also has outstanding practical performance.

Exploration and Practice in Combining Teaching and Competition in the Curriculum Group of "Radio Frequency Communication and Antenna"

Wang Ping, Shao Yu, Ye Zhihong, Li Qiang

2021, 6(12):  17-22. 

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In order to stimulate the practical ability and consolidate the theoretical knowledge of students， and taking into consideration the needs of training innovative engineering talents， the "antenna system design" competition mode is proposed. The course adopts a variety of incentives such as the combination of teaching and competition， innovative credit acquisition， prize awards， as well as the promotion of outstanding works， outstanding ideas， the activity system and the working mechanism to encourage students' active participation， and to expand the influence of the curriculum group in the school. The combination mode of teaching and competition adopts knowledge-expansion mode， thinking-training mode， and achievement-evaluation mode， which effectively cultivates students' independent research ability， teamwork ability， innovation ability and comprehensive design ability， and significantly improves the quality of undergraduate training.

Design and Implementation of Ethnic Costume Recognition System Based on Faster-RCNN

Zhao Enming, Yang Song, Yao Zhiqiang

2021, 6(12):  23-28. 

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Ethnic costumes is a treasure of the Chinese nation， and the identification of ethnic costumes has played a positive role in promoting ethnic cultures. In the field of target recognition， convolutional neural networks have an outstanding performance. In order to distinguish traditional ethnic costumes， a recognition system based on Faster-RCNN algorithm was designed and implemented. The system realizes the identification of Bai， Miao and Mongolian costumes， and can output target-classification labels， confidence intervals and coordinate information. At the same time， the system can recognize multi-target costumes. After testing， the MAP value of the recognition model is 67.88%， which achieves a better effect of ethnic costume recognition.

First-Principles Study of Se-Doped Cu2S and Cu2O

Luo Liang, Xie Zaixin, Duan Zhuoqi, HuYongmao, Zhou Bao

2021, 6(12):  29-35. 

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Both Cu2S and Cu2O are p-type semiconductors with direct band gaps. Due to the appropriate band gap values （Cu2S~1.2 eV， Cu2O~2.2 eV）， they have potential application value in solar cell electrode materials. However， their carrier mobility is not high， and the band structure needs to be further optimized. A theoretical simulation study of Se doping was carried out on Cu2S and Cu2O， and the electronic structure and optical properties were calculated by first principles. It is found that the band gap of Se-doped Cu2S decreases and the ionic bond between atoms becomes weaker. The band gap of Se-doped Cu2O increases， free electrons appear， and the mobility of carriers is improved. In general， the light absorption efficiency of Cu2S and Cu2O doped with a certain amount of Se have been improved.

Research on Optimal Design of Building Concrete Mixture Based on DPO-BP

Chen Yan

2021, 6(12):  36-39. 

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In order to solve the defects of poor training effects and low generalization ability of neural network in the prediction of concrete compressive strength， in this paper， the dolphin algorithm （DPO） and BP neural network are combined to construct a BP neural network model based on DPO（DPO-BP） and applied to optimize the concrete mixing ratio， and a set of feasible concrete mixing-ratio design schemes are proposed. The results show that compared with algorithms， genetic optimization BP neural network （GA-BP） and particle swarm optimization BP neural network （PSO-BP）， this optimization method has the advantages of fast convergence and good robustness. The DPO-BP algorithm has high solution accuracy and strong portability. It can also be used for slope stability judgment， machine fault diagnosis， air and water quality evaluation and many other fields. It has very significant engineering value.

Effect of Bi3+ on the Visible Light Photocatalyic Activity of AgInS2

Wang Jinxue, Wang Ying, Yan Ya

2021, 6(12):  40-45. 

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AgInS2 and AgInS2 with different ratios of Bi3+（denoted as Bi-AgInS2） were prepared by the low temperature liquid method. The visible light photocatalytic activities of AgInS2 and Bi-AgInS2 were studied through the degradation of Rhodamine B（RhB） and 4-nitrophenol（PNP）. The experimental results displayed that the prepared samples without adding Bi3+ were orthorhombic phase AgInS2， while samples were face-centered cubic structure when different amount of Bi3+ were added into AgInS2. The addition of Bi3+ did not change the elements oxidation state in the AgInS2， but enhanced the binding ability of Ag+ to electrons， and weakened the binding ability of S2- to electrons. As the amount of Bi3+ increased， the visible light absorption abilities of the samples increased， but the emission intensities decreased. Bi-AgInS2 with the optimal ratio（Bi3+ ∶In3+=14.3∶2.7） showed the highest visible light photocatalytic activity for the degradations of RhB and PNP. 

Study on the Preparation and Visible-Light Photocatalyic Activity of Mg2+ Doped AgInS2

Li Xiaoqing, Qiao Rong, Yan Ya

2021, 6(12):  46-50. 

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Mg-AgInS2 with different ratios of Mg2+ ∶In3+ were prepared by the low temperature liquid method， and the morphology， structure and optical properties of as-prepared samples were characterized by scanning electron microscope（SEM）， fluorescence spectrum， X-ray photoelecrton spectroscopy（XPS）， ultraviolet-visible diffuse reflection spectrometry and X-ray doffraction（XRD）. The effect of doping Mg2+ amount on the visible-light photocatalytic activity of AgInS2 was investigated through the degradation1 of Rhodamine B （RhB） under visible light irradiation. The experimental results displayed that Mg2+ was successfully doped into AgInS2， and Mg-AgInS2 with Mg2+∶ In3+=11∶6 showed the highest photocatalytic activity. The degradation efficiency of RhB by Mg-AgInS2 with the optimal ratio could reach 93% under visible light irradiation for 90 min.

Determination of 10 Trace Elements in Stems of Dendrobium stuposum by ICP-OES

Su Yanmei, Zhu Xiuying, Bi Yunfeng, Yang Minghui

2021, 6(12):  51-54. 

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The powders of stems from Dendrobium stuposum were digested by microwave with nitric acid and determined by inductively coupled plasma opitcal emission spectrometry（ICP-OES）.  Through methodological examination, the results showed that the correiation coefficients（r） of 10 target elements（Fe， Al， Mn， Zn， Cr， Cu， Ni， Co， Cd and Pb） were 0.999 7-0.999 9. The limit of detection （LOD） and the limit of quantitation （LOQ） were 0.03-7.36 ng/L and 0.11-24.52 ng/L， respectively. The relative standard deviation （RSD） values of precision were lower than 2.68%. The average recoveries ranged from 92% to 104%. The developed method can be used to simultaneously determine the contents of 10 trace elements in stems of D. stuposum.

Analysis of Volatile Components from the Flowers of Juglans regia by GC-MS

Li Guixiang, Ma Sha, Cui Qingde, Fang Huixiang

2021, 6(12):  55-58. 

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The crude powder of the flowers of Juglans regia was extracted by ultrasonic with ethyl acetate， and the volatile components were analyzed by GC-MS. More than 60 kinds of volatile components were isolated from the coarse powder of the flowers， and were identified by NIST 2017 mass spectrometry retrieval database and related literature data. A total of 29 volatile components were identified. The volatile components from the flowers of J. regia are complex and diverse. The main components are terpenoids， alcohols， alkanes， esters and so on. These constituents have a wide range of biological activities， which can provide scientific reference for the development， utilization and quality control of the flowers of J. regia.

Preliminary Study on Competition and Synergistic Mechanisms of Nematode-Trapping Fungi in Sterile Soil

Liu Lilei, Deng Wei, Yang Xiaoyan, Xiao Wen, She Rong,

2021, 6(12):  59-64. 

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Objective： To gain insight into the competition and coexistence relationships among different microbiology species.Methods： Three nematode-trapping fungi species from genus Arthrobotrys were inoculated into sterile soil by different patterns， and the occurrence frequencies were assessed every week. Results：The occurrence frequencies of A. musiformis was the highest and it can assist the other two species to exist through the whole experiment period when three species were mixed inoculated at same time point. There was priority effect of mixed inoculation at different time points， and its duration was affected by the interspecific synergy. In addition， the inoculation of A. thaumasium had positive effects on the occurrence frequencies value of A. oligospora. Conclusion：Different nematode-trapping fungi species from same genus can coexist competitively， and the priority effects and synergistic effects affect the final community composition.

Purification Effects of Aquatic Plants on Nitrogen and Phosphorus in Eutrophic Water Bodies

Yang Xue, Li Yuancheng, Wang Huifang, Zhou Jun, , Lü Dongpeng,

2021, 6(12):  65-68. 

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An indoor hydroponic experiment was conducted to study the removal effects of nitrogen and phosphorus in eutrophic water of four wetland plants in Mocanxi river entering Erhai Lake， i.e. Myriophyllum verticillatum L.， Eichhornia crassipes （Mart.） Solms， Thalia dealbata， Scirpus validusVahl，and plant communities they construct. The international standard detection method and weighing method were used to measure and analyze the three indexes of total nitrogen， ammonia nitrogen and total phosphorus in water and the fresh weight of plants regularly， and the aquatic plants with strong purification ability of nitrogen and phosphorus in water were screened out.The results showed that the four plants and their communities had a good purification effect on nitrogen and phosphorus in eutrophic water.Among them， the growth of Eichhornia crassipes （Mart.） Solms is good and its purification effect is the best.

The Value and Development of Chen Taijiquan from the Perspective of Ｎational Public Fitness

Hou Guoliang, Qi Hengbo, Long Fengying

2021, 6(12):  69-73. 

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Using the methods of literature review， interviews， and field investigations， and from the perspective of national fitness， this paper analyzes the origin， current situation， value and development of Chen Taijiquan， and points out that Chen Taijiquan has great value for fitness， entertainment， culture and education. However， in its inheritance and development， there are problems such as the aging of the inheritors， the simplification of inheritance mode， and its space being squeezed by competitive sports. This study shows that Chen Taijiquan could be well inherited and developed if we take the integration of sports and education as the carrier， the national fitness as an opportunity， the Belt and Road Initiative as a breakthrough， the holding of competitions as the media， and the Internet media as a support.

Analysis of Physical Condition of Students from Different Altitudes in Dali University

Zhang Qian, Yin Chunlei, Li Lijuan

2021, 6(12):  74-79. 

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Objective：To understand the physical health levels， features， changes and development trends of college students from different altitude areas in the plateau area. Methods： This study conducts a statistical analysis based on the physical fitness test data of students from Class of 2015 in Dali University for four consecutive years. Results： There are statistical differences in the body shape， endurance quality event of students from different altitude areas； for the strength quality event， only the differences among the boys were statistically significant， and for the speed quality event, explosive quality event and flexibility quality event， the differences were not statistically significant. Conclusion： There are differences in the physical fitness levels of students from different altitudes studying in plateau areas. The speed， endurance， strength and explosiveness of students in low altitude areas are lower than those from middle and high-middle altitude areas.

Sentiment Analysis and Implementation of Online Reviews Based on Machine Learning

Shang Yongmin, Zhao Yuqin

2021, 6(12):  81-86. 

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This study collected comment data from hot-selling laptops on JD.com， and used Python to perform data cleaning， text segmentation， and stop-words filtering. Afterwards， Naive Bayes， support vector machine（SVM） method， and SnowNLP method in machine learning methods are used to classify data for sentiment. By comparing the classification results of the three methods， the optimal classification method for online comment sentiment classification was selected. The LDA topic model is used to divide different topics， extract the positive sentiment word set and the negative sentiment word set in the review set， and visualize the conclusion data to further explore the highlights and drawbacks of the product. Finally， a "SnowNLP+ LDA" online sentiment analysis program based on machine learning was constructed.

Study on Optimal Extraction Duration of Soil-Nematode Based on Baermann Funnel Method

Pu Guoqing, Luo Dan, Zhao Chengfa, Tan Kun, Liu Shuoran, Xiao Wen, Li Yanpeng

2021, 6(12):  87-90. 

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The Baermann funnel method is common in soil-nematode extraction. However， it has been found that the extraction durations in studies varies greatly， and there is a lack of agreed standard. To explore the optimal extraction duration， the Baermann funnel method was used to extract soil-nematode for 72 h， and the cumulative separation rates were calculated for 12， 24， 36， 48，60 and 72 h respectively. The results showed that in terms of the separation of taxa， 24 h was the peak value， and it has no difference from that of 48 h（21.00±2.54 vs. 21.00±1.00，P=0.817）； in terms of the separation of numbers， 36 h was the most appropriate time， and the cumulative separation rate was 99.63%. A total of 24 777 nematodes were isolated in the experiment， belonging to 2 classes， 6 orders， 21 families and 35 genera， covering a large number of nematode groups and having universal applicability. Considering the taxa and numbers， the recommended separation time of the Bellman funnel method is 36 h.

Community Structure of Taxus yunnanensis in Yunling Provincial Nature Reserve

Ma Guanyuan, Huang Zhipang, Zhang Caicai,

2021, 6(12):  91-96. 

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In order to study the community structure of Taxus yunnanensis， the Taxus yunnanensis community in the Yunling Provincial Nature Reserve was taken as the research object. Based on the analysis of the survey data of 5 field community samples， it was found that there were 57 species of vascular plants in the community， belonging to 29 families and 48 genera. The community stratification is obvious. The dominant species in the tree stratum， shrub stratum and herb stratum are Taxus yunnanensis， Fargesia spathacea and Duchesnea indica respectively. Based on the analysis of species diversity， the Shannon-Wiener index， Simpson index and Pielou evenness index is herb stratum> tree stratum> shrub stratum. Taxus yunnanensis has sufficient seedling bank， but lacks saplings， indicating that the establishment of the reserve has a positive effect on the protection of Taxus yunnanensis， but the protection still needs to be strengthened to reduce the impact of human disturbance.

Preliminary Study on the Effects of Different Preservatives on Cut Flowers of Alstroemeria hybrida

Sen Ping, Kong Lingfang

2021, 6(12):  97-100. 

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Alstroemeria hybrida were tested using nine preservatives with 5% sucrose and different concentration of 8-HQC， STS， and 6-BA to evaluate the fresh-keeping effects. The results suggested that the best preservatives combination is 5% sucrose + 200 mg/L 8-HQC + 0.2 mmol/L STS + 50 mg/L 6-BA.