作者机构：
[Liu, Yiying] Hunan City Univ, Coll Fine Arts & Design, Yiyang 413000, Hunan, Peoples R China.;[Liu, Yiying] Sehan Univ, Grad Sch, Dept Educ, Chungnam 58447, South Korea.;[Ko, Young Chun; Ko, YC] Sehan Univ, Dept Teaching Profess, Chungnam 58447, South Korea.
通讯机构：
[Ko, YC ] S;Sehan Univ, Dept Teaching Profess, Chungnam 58447, South Korea.
关键词：
Education;Digital art;Internet of Things;Sensors;Real-time systems;Optimization;Surveys;Information technology;Deep learning;deep learning;digitization;teaching platform
通讯机构：
[Lixiong Li] S;School of Mechanical and Electrical Engineering, Hunan City University, Yiyang 413099, China
关键词：
Quasi -Z -source inverter;Cascaded H -bridge;Battery energy storage;State -of -charge
摘要：
Battery energy stored quasi-Z source cascaded H-bridge based photovoltaic power generation system combines advantages of quasi-z-source inverter, cascaded H-bridge, and battery energy storage system. However, the battery state of charge imbalance between the cascaded H-bridge inverter modules would reduce the system's performance and efficiency and potentially cause the system to fail. An integrated control technique of adaptive state of charge balancing based on gain scheduling and three-phase power balance of third harmonic injection based on fundamental frequency whole zero sequences is suggested for the quasi-Z source cascaded H-bridge battery storage system. Based on the mathematical relationship between the instantaneous state of charge of battery energy stored quasi-z-source cascaded H-bridge and the voltage reference value, this method updates the proportional controller gain in each sampling period. It combines the third harmonic injection method based on the fundamental frequency zero sequence to select the optimal modulation ratio Mn. Rapid state of charge balancing is accomplished without overmodulation while increasing the power balance range and decreasing DC link voltage swings. The simulation results validate the method's usefulness. The simulation results validate the proposed control method for ensuring power distribution between each phase and achieving a balanced state of charge of the battery energy stored quasi-Z source cascaded H-bridge photovoltaic system's battery energy storage.
期刊：
Wireless Personal Communications,2023年128(1):741-741 ISSN：0929-6212
通讯作者：
Weihong Kuang
作者机构：
[Xiaobo Min] School of Metallurgy and Environment, Central South University, Changsha, China;[Weihong Kuang] College of Humanities, Hunan City University, Yiyang, China
通讯机构：
[Weihong Kuang] C;College of Humanities, Hunan City University, Yiyang, China
作者机构：
[Sheng, Haiquan; Zhou, Lv; Chen, Yukai; Xian, Lingxiao; Ma, Shubian] Guilin Univ Technol, Coll Geomatics & Geoinformat, Guilin 541004, Peoples R China.;[Huang, Changjun] Hunan City Univ, Sch Municipal & Surveying Engn, Yiyang 413000, Peoples R China.;[Yang, Fei] China Univ Min & Technol Beijing, Geosci & Survey Engn Coll, Beijing 100083, Peoples R China.
通讯机构：
[Lv Zhou] C;College of Geomatics and Geoinformation, Guilin University of Technology, Guilin 541004, China<&wdkj&>Author to whom correspondence should be addressed.
关键词：
InSAR;persistent scatterer;Beijing;plain;Sentinel-1A;time series
摘要：
Surface subsidence is a serious threat to human life, buildings and traffic in Beijing. Surface subsidence is closely related to human activities, and human activities in Beijing area showed a decreasing trend during the Corona Virus Disease 2019 (COVID-19). To study surface subsidence in Beijing before and after the COVID-19 outbreak and its causes, a total of 51 Sentinel-1A SAR images covering Beijing from January 2018 to April 2022 were selected to derive subsidence information by Time Series Interferometry Synthetic Aperture Radar (TS-InSAR). The results of surface subsidence in Beijing demonstrate that Changping, Chaoyang, Tongzhou and Daxing Districts exhibited the most serious subsidence phenomenon before the COVID-19 outbreak. The four main subsidence areas form an anti-Beijing Bay that surrounds other important urban areas. The maximum subsidence rate reached −57.0 mm/year. After the COVID-19 outbreak, the main subsidence area was separated into three giant subsidence funnels and several small subsidence funnels. During this period, the maximum subsidence rate was reduced to −43.0 mm/year. Human activity decrease with the COVID-19 outbreak. This study effectively analysed the influence of natural factors on surface subsidence after excluding most of the human factors. The following conclusions are obtained from the analysis: (1) Groundwater level changes, Beijing’s geological structure and infrastructure construction are the main reasons for surface subsidence in Beijing. (2) Seasonal changes in rainfall and temperature indirectly affect groundwater level changes, thereby affecting surface subsidence in the area. (3) The COVID-19 outbreak in early 2020 reduced the payload of Beijing’s transportation facilities. It also slowed down the progress of various infrastructure construction projects in Beijing. These scenarios affected the pressure on the soft land base in Beijing and reduced the surface subsidence trend to some extent.
期刊：
Waves in Random and Complex Media,2023年 ISSN：1745-5030
通讯作者：
Hongjian Li
作者机构：
[Cuixiu Xiong] College of Information and Electronic Engineering, Hunan City University, Yiyang, People’s Republic of China;[Hongjian Li; Chao Liu; Banxian Ruan; Min Li; Enduo Gao] School of Physics and Electronics, Central South University, Changsha, People’s Republic of China
通讯机构：
[Hongjian Li] S;School of Physics and Electronics, Central South University, Changsha, People’s Republic of China
摘要：
We propose a hybrid structure composed of a silver mirror and two spaced graphene monolayers to enhance light absorption. A broad plasmon-induced reflection (PIR) window can be generated because of the destructive interference between the bright and dark modes, resulting in a dual-narrowband absorption switching effect. The dual-narrowband absorption switch is strongly dependent on the geometric structure parameters and dynamic tuning parameter of the hybrid structure, and each parameter has a wide tuning range for absorption state ‘on/on’. Especially, compared with the hybrid structure composed of a graphene monolayer and one-dimensional photonic crystal (1D PC), the proposed structure is simpler and easier to fabricate, and the dynamic tuning width of Fermi energy of graphene for light absorption state ‘on/on’ is significantly broadened (∼3 times). Compared with plasmon-induced transparency (PIT) systems, the absorption performance of graphene is greatly enhanced, and the absorption is increased from about 50% to higher than 97%. Moreover, by adjusting the widths of the graphene monolayers, NAND and NOR logic gates are realized, and the output contrast between logic states ‘1’ and ‘0’ is high up to 18.6 dB. This study may provide an approach to construct dual-narrowband absorption switches, perfect absorbers, and plasmon logic gates.
通讯机构：
[Sen Lin] S;State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, College of Mechanical and Vehicle Engineering, Hunan University, Changsha 410082, China
摘要：
Current analytical and simulation models for lithium battery thermal behaviour encounter efficiency or accuracy challenges in energy storage applications. In this paper, an analytical thermal analysis approach for prismatic lithium cells considering dynamic non-uniform characteristics is proposed to calculate the dynamic temperature distribution. A thermal circuit model and analytical differential equation group were formulated to capture the dynamic non-uniform thermal characteristics during charging/discharging. A solving algorithm was provided to balance accuracy and efficiency by establishing an iterative mechanism over the modelling parameters. The proposed model and algorithm were applied to three commercial lithium cells. The experiments under various charge-discharge conditions verified the millisecond-level computational cost and less than 3 % calculation accuracy. The parameter calibration, iteration mechanism, and reproducible codes enhanced the engineering applicability. The performance of the approach suggested its excellent potential in battery thermal management for energy storage.
期刊：
Internet Technology Letters,2023年 ISSN：2476-1508
通讯作者：
Yuanqing Li
作者机构：
[Yuanqing Li] School of Physical Education, Huanghuai University, Zhumadian, China;[Juan Liu] School of Physical Education, Hunan City University, Yiyang, China
通讯机构：
[Yuanqing Li] S;School of Physical Education, Huanghuai University, Zhumadian, China
摘要：
Abstract Yoga, as a kind of body building exercise, has always been loved by people. However, many people suffer from yoga training injuries due to long‐term incorrect posture and wrong exercise methods. There is an urgent need for a technology to help people detect and improve yoga training methods. Based on the past computer assistance method, this paper started from a new idea, and adopted the method of multi‐sensor information fusion to detect yoga training, aiming to help the masses better participate in yoga training. In this study, 50 volunteers were invited to participate in the comparative experiment. Based on multi‐sensor information fusion, and by building a human model, the tension and compression data before and after yoga training were compared to analyze the differences before and after calculation. It was concluded that the more sensors, the higher the degree of information fusion, and the lower the yoga training injury index. The injury index of yoga training without multi‐sensor information fusion technology in the early stage was 0.39. With the increase of the number of sensors, the injury index of yoga training has gradually decreased to 0.02, which was more than 5 percentage points lower than that of the previous methods. The experiment showed that the method of yoga training damage detection based on multi‐sensor information fusion was feasible, which also provided a new idea for the research of yoga training injury detection methods.
期刊：
International Journal of Information and Communication Technology,2023年22(1):91–105 ISSN：1466-6642
作者机构：
1. School of Art, Hunan City University, Yi Yang - 413000, Hunan, China
关键词：
stochastic forest algorithm;painting features;feature classification;uniform model;LBP value
摘要：
In order to solve the problems of time-consuming and low classification accuracy of feature extraction in traditional painting feature classification methods, a new method based on stochastic forest algorithm is proposed. The colour feature of painting is converted into HSV component, and the original LBP value of the painting image is converted into 59-dimension feature vector by uniform mode to extract the painting texture feature. The wavelet transform method is used to obtain the high and low frequency band signal of painting features, and the noise reduction of painting features is completed. The similarity coefficient is determined by stochastic forest algorithm, and the similarity matrix of painting features is obtained to complete the classification of painting features. The experimental results show that the accuracy of the classification method can reach 98% and the time is less than 2 s.
作者机构：
[Hu, Xiaojie; Dong, Fuxiao; Wang, Haiou; Zhao, Bojun; Huo, Dexuan; Wang, Yan] Hangzhou Dianzi Univ, Inst Mat Phys, Key Lab Novel Mat Sensor Zhejiang Prov, Hangzhou 310018, Peoples R China.;[Tan, Weishi] Hunan City Univ, Coll Informat & Elect Engn, All Solid State Energy Storage Mat & Devices Key L, Yiyang 413002, Peoples R China.;[Tan, Weishi] Nanjing Univ Sci & Technol, Dept Appl Phys, Key Lab Soft Chem & Funct Mat, Minist Educ, Nanjing 210094, Peoples R China.
通讯机构：
[Weishi Tan; Haiou Wang] A;Authors to whom correspondence should be addressed.<&wdkj&>All-Solid-State Energy Storage Materials and Devices Key Laboratory of Hunan Province, College of Information and Electronic Engineering, Hunan City University, Yiyang 413002, China<&wdkj&>Key Laboratory of Soft Chemistry and Functional Materials, Ministry of Education, Department of Applied Physics, Nanjing University of Science and Technology, Nanjing 210094, China<&wdkj&>Authors to whom correspondence should be addressed.<&wdkj&>Key Laboratory of Novel Materials for Sensor of Zhejiang Province, Institute of Material Physics, Hangzhou Dianzi University, Hangzhou 310018, China
关键词：
magnetic properties;magnetocaloric;manganite;film;Pr0.7Sr0.3MnO3
摘要：
The magnetic behaviors and magnetocaloric effect (MCE) of Pr0.7Sr0.3MnO3 (PSMO-7) film grown on a (001) SrTiO3 single-crystal substrate by a pulsed laser deposition (PLD) were studied in this paper. X-ray diffraction with a high resolution (HRXRD) measurement shows that PSMO-7 film is grown with a (001) single orientation. The magnetic properties and the MCE related to the ferromagnetic (FM) phase transition of the PSMO-7 film are investigated using the temperature dependence of magnetization M(T) and the magnetic field dependence of magnetization M(H). The M(T) data suggest that with decreasing temperatures, the PSMO-7 film goes through the transition from the paramagnetic (PM) state to the FM state at around the Curie temperature (T-C). The T-C (about 193 K) can be obtained by the linear fit of the Curie law. Magnetic hysteresis loop measurements show that the PSMO-7 film exhibits the FM feature at temperatures of 10, 100, and 150 K (low magnetic hysteresis can be found), while the film reveals the PM feature with the temperature increased up to 200 and/or 300 K. The research results of M(H) data are consistent with the M(T) data. Furthermore, the magnetic entropy change (-delta S-M) of the PSMO-7 film was studied. It was found that the maximum value of (-delta S-M) near T-C reaches about 4.7 J/kg & BULL;K under the applied field change of 20 kOe, which is comparable to that of metal Gd (-delta S-M of 2.8 J/kg K under 10 kOe), indicating the potential applications of PSMO-7 film in the field of magnetic refrigeration.
期刊：
Frontiers in Environmental Science,2023年11:1270921 ISSN：2296-665X
通讯作者：
Ning, QM
作者机构：
[Ji, Qianfu; Yang, Hua; Zhou, Hui; Song, Qidi; Lai, Nan] Hunan Prov Terr Space Survey & Monitoring Inst, Changsha, Peoples R China.;[Ning, Qimeng; Zeng, Zhiwei; Ning, QM] Hunan City Univ, Coll Architecture & Urban Planning, Yiyang, Peoples R China.
通讯机构：
[Ning, QM ] H;Hunan City Univ, Coll Architecture & Urban Planning, Yiyang, Peoples R China.
关键词：
Urban-water coupling;Water ecological space;Resilience control;digitalization;Dongting Lake area
摘要：
Introduction: The construction of digital governance of national land space depends greatly on the development of a digital model for robust control of water and ecological space. However, how changes to the urban-water coupling relationships affect the resilience control of water ecological space is rarely reported.Methods: The evolution characteristics of urban and water space in the study area from 2000 to 2020 and the correlation between them are analyzed based on the grid analysis using InVEST and Moran'I methods. Based on the theory of human-environment interaction territorial system to provide a theoretical framework to explain the urban and water space. We used digital to construct an resilience control framework in the Dongting Lake area based on the correlation between the urban and water space.Results: The results show that: 1) From 2000 to 2020, the geographical evolution of towns and cities in the research area displayed obvious spatial variation in intensity, indicating a process of expansion and change. The regional and temporal fluctuations of the water conservation function are significant. The mountainous areas in the east, south, and northwest are where the high values of the water conservation function are primarily found. These regions have more vegetation, which increases the water conservation function. 2) According to the results of local binary spatial autocorrelation analysis, it can be seen that from 2000 to 2020, the high-high agglomeration of town space and water-related is mainly distributed in Linxiang City, Yueyang County, Miluo City, Li County, and Yiyang City, and the low-low agglomeration is mainly distributed in Dongting Lake, Datong Lake, and along the Yangtze River. 3) Based on how urban spatial evolution affects water ecological space, we construct a theoretical framework of urban-water coupling and establish a digital model of water ecological space resilience control in the Dongting Lake area from four perspectives: threshold, visualization, dynamics, and intelligence.
作者机构：
[Cao, Kesheng; Wang, Yabo] School of Chemistry and Environmental Engineering, Henan Key Laboratory of Germplasm Innovation and Utilization of Eco-Economic Woody Plant, Pingdingshan University, Weilai Road, Pingdingshan, 467000, China;[Tian, Zhengshan] School of Chemistry and Environmental Engineering, Henan Key Laboratory of Germplasm Innovation and Utilization of Eco-Economic Woody Plant, Pingdingshan University, Weilai Road, Pingdingshan, 467000, China. tianzhengshan@163.com;[Zhang, Xunyou] College of Mechanical and Electrical Engineering, Chizhou University, Chizhou, 247000, China. xyzhang@czu.edu.cn;[Zhu, Qiuxiang] College of Information and Electronic Engineering, Hunan City University, Yingbin East Road, Yiyang, 413000, China
通讯机构：
[Zhang, Xunyou] C;[Tian, Zhengshan] S;School of Chemistry and Environmental Engineering, Henan Key Laboratory of Germplasm Innovation and Utilization of Eco-Economic Woody Plant, Pingdingshan University, Weilai Road, Pingdingshan, 467000, China.;College of Mechanical and Electrical Engineering, Chizhou University, Chizhou, 247000, China.
摘要：
As a basic building block of graphene-based materials, graphene oxide (GO) plays an important role in scientific research and industrial applications. At present, numerous methods have been employed to synthesize GO, there are still some issues that need to be solved, thus it is of importance to develop a green, safe and low-cost GO preparation method. Herein, a green, safe and fast method was designed to prepare GO, namely, graphite powder was firstly oxidized in a dilute sulfuric acid solution (H(2)SO(4), 6mol/L) with hydrogen peroxide (H(2)O(2), 30 wt%) as oxidant, and then exfoliated to GO by ultrasonic treatment in water. In this process, H(2)O(2) was the only oxidant, and no other oxidants were used, thus the explosive nature of GO preparation reaction in the conventional methods could be completely eliminated. This method has other advantages such as green, fast, low-cost and no Mn-based residues. The experimental results confirm that obtained GO with oxygen-containing groups has better adsorption property compared to the graphite powder. As adsorbent, GO can remove methylene blue (50mg/L) and Cd(2+) (56.2mg/L) from water with removal capacity of 23.8mg/g and 24.7mg/g, respectively. It provides a green, fast andlow-cost method to prepare GO for some applications such as adsorbent.
