期刊:
Journal of Computational Methods in Sciences and Engineering,2023年23(1):433-443 ISSN:1472-7978
作者机构:
College of Teacher Education, Hunan City University, Yiyang, Hunan, China;Mechanical and Electrical Engineering College, Hunan City University, Yiyang, Hunan, China
关键词:
Deep learning;offline learning;classroom concentration;identification;measures
摘要:
During the reform of the deep teaching model, students’ deep learning quality was affected and restricted by various factors. During the offline class learning process of students, the concentration of deep learning directly affects the quality of learning. This article analyzes the study focus of students in deep learning models, conducts research on the quality of class offline learning of different students, quantifies the factors that affect students’ deep learning, and builds an analysis model for quantitative comparison. Important influence factor affecting students’ offline classroom concentration, through targeted measures, improve teaching methods and quality, optimize classroom teaching models, use various methods and measures to effectively improve learning focus, and further promote the reform of teaching models. The level of concentration of students’ learning has been steadily improved, and the model of deep learning is proposed to help the teaching model reform.
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.
摘要:
Efflorescence is a concerning issue in geopolymer formulations. By accelerating efflorescence, the efflorescence behavior and compressive strength evolution were analyzed for metakaolin (MK)-based geopolymers cured at various temperatures and times. Mercury Intrusion Porosimetry (MIP) was the primary characterization method utilized in this study. Based on the pore structure, we identified the influence of pore structure on efflorescence behavior and compressive strength evolution. Those results showed that long-term and initial high-temperature curing played a negative role in mitigating efflorescence. Long-term curing refined the pore size, facilitating alkali salt migration to the surface. Initial high-temperature curing enhanced pore connectivity, which facilitated alkali salt movement. The number of pores below 20 nm governs the effect of efflorescence on compressive strength. Crystallization degrades geopolymer with a large number of pores below 20 nm. This study provides a new understanding of the effect of pore structure on efflorescence and the evolution of compressive strength during efflorescence and facilitates optimization of geopolymer formulations to relieve efflorescence.
通讯机构:
[Chen, Yaoning] K;[Li, Yuanping] C;Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China. Electronic address:;College of Municipal and Mapping Engineering, Hunan City University, Yiyang, Hunan 413000, China. Electronic address:
摘要:
Humic substances (HSs) are key indicators of compost maturity and are important for the composting process. The application of additives is generally considered to be an efficient and easy-to-master strategy to promote the humification of composting and quickly caught the interest of researchers. This review summarizes the recent literature on humification promotion by additives in the composting process. Firstly, the organic, inorganic, biological, and compound additives are introduced emphatically, and the effects and mechanisms of various additives on composting humification are systematically discussed. Inorganic, organic, biological, and compound additives can promote 5.58-82.19%, 30.61-50.92%, 2.3-40%, and 28.09-104.51% of humification during composting, respectively. Subsequently, the advantages and disadvantages of various additives in promoting composting humification are discussed and indicated that compound additives are the most promising method in promoting composting humification. Finally, future research on humification promotion is also proposed such as long-term stability, environmental impact, and economic feasibility of additive in the large-scale application of composting. It is aiming to provide a reference for future research and the application of additives in composting.
摘要:
Super-hard abrasive grinding is considered to be the main approach to realize precision and ultra-precision machining of difficult-to-machine materials such as cemented carbide, engineering ceramics, titanium alloys and superalloy materials encountered. However, heavy grinding force, high grinding temperature and poor surface integrity are prone to be encountered in conventional negative rake angle grinding of difficult-to-machine materials. In response to these problems, a novel concept of positive rake angle grinding is first proposed and an abrasive grain regularly arranged binder-less polycrystalline diamond face grinding wheel with positive rake angle has been designed and fabricated by femtosecond laser ablation. To evaluate the grinding performance of the face grinding wheel with positive rake angle, grinding experiments of YG8 cemented carbide are conducted and compared with the traditional electroplated diamond grinding tool with equivalent abrasive grain dimension and distribution. The results show that compared with the conventional negative rake angle grinding, the normal and tangential forces in positive rake angle face grinding are reduced by 30.3 % similar to 36.4 % and 21.1 % similar to 29.3 %, respectively, and the ratio of normal to tangential force is reduced by 12.6 % similar to 20.3 %. The surface roughness and average depth of subsurface metamorphic layer are also significantly smaller. The laser fabricated polycrystalline diamond face grinding wheel also has better wear resistance in the grinding of cemented carbide. Therefore, it can be concluded that better ground surface quality is obtained by the novel grinding wheel with positive rake angle. The innovative grinding method can fill the research gap on the grinding mechanism of positive rake angle grinding and further enrich the grinding theory of difficult-to-machine materials.
作者机构:
[Luo, Xiaoyong; Long, Hao; Dong, Shuang; Luo, XY; Liu, Jinhong] Cent South Univ, Sch Civil Engn, Changsha 410000, Peoples R China.;[Long, Hao] Hunan City Univ, Sch Civil Engn, Yiyang 413000, Peoples R China.;[Luo, Xiaoyong; Luo, XY] Cent South Univ, Hunan Prefabricated Bldg Engn Technol Res Ctr, Changsha 410000, Peoples R China.
通讯机构:
[Luo, XY ] C;Cent South Univ, Sch Civil Engn, Changsha 410000, Peoples R China.;Cent South Univ, Hunan Prefabricated Bldg Engn Technol Res Ctr, Changsha 410000, Peoples R China.
关键词:
prefabricated components;tolerance;manufacturing dimensions;dimensional chain;monte carlo method;installation reliability
摘要:
Abstract: During the installation process of prefabricated components, deviations in dimensions and installation positions can occur due to construction quality issues, and the accumulation of these deviations can impact the reliability of component installation. However, the current approach to addressing accumulated deviations in the component installation process primarily relies on the trial-and-error method, lacking a solid theoretical foundation. This paper introduces the dimensional chain theory derived from mechanical engineering and presents a method to evaluate the installation reliability of prefabricated components in concrete structures. First, based on extensive measurements of installation deviations, it was found that the installation deviations of components followed a log-normal distribution. By analyzing the relationship between installation deviations and the acceptance rate, it was determined that for a 90% acceptance rate, the installation position deviation should be 8.6 mm for prefabricated wall panel components and 7.3 mm for prefabricated column components. Subsequently, the concept of dimensional chain theory from mechanical engineering was introduced to establish a limit state equation for quantifying the installation reliability of prefabricated components in concrete structures. By applying this theory, appropriate component fabrication dimensions could be determined to achieve a 95% level of installation reliability. Finally, by using the Monte Carlo method to solve the installation limit state equation for an actual engineering project, recommended fabrication dimensions for the components were obtained. The results indicate that within the horizontal axis, the length deviation of prefabricated beams, and the width fabrication dimension of columns needed to be reduced by 2.3 mm to 2.9 mm. Within the vertical axis, the length dimension of columns and the height dimension of beams had to be reduced by 0.9 mm to 2.2 mm to achieve a 95% level of installation reliability. Keywords: prefabricated components; tolerance; manufacturing dimensions; dimensional chain; monte carlo method; installation reliability
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] A;[Haiou Wang] K;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&>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:
Abstract: 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 (TC). The TC (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 ( − Δ S M ) of the PSMO-7 film was studied. It was found that the maximum value of ( − Δ S M ) near TC reaches about 4.7 J/kg·K under the applied field change of 20 kOe, which is comparable to that of metal Gd ( − Δ 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. Keywords: magnetic properties; magnetocaloric; manganite; film; Pr0.7Sr0.3MnO3
期刊:
FRONTIERS IN EARTH SCIENCE,2023年11:1112772 ISSN:2296-6463
通讯作者:
Gao, H.
作者机构:
[Li, Ping] Tibet Agr & Anim Husb Univ, Coll Resources & Environm, Linzhi, Peoples R China.;[Gao, Hongshan; Yan, Tianqi] Lanzhou Univ, Coll Earth & Environm Sci, Key Lab Western Chinas Environm Syst, Minist Educ, Lanzhou, Peoples R China.;[Li, Zongmeng] Xinyang Normal Univ, Sch Geog Sci, Xinyang, Peoples R China.;[Wu, Yajie] Wuwei 1 Middle Sch, Wuwei, Peoples R China.;[Liu, Fenliang] Hunan City Univ, Sch Municipal & Surveying Engn, Yiyang, Peoples R China.
通讯机构:
[Gao, H.] K;Key Laboratory of Western China’s Environmental Systems (Ministry of Education), China
关键词:
downstream fining;gravel-sand transition;median grain size;river sediment;Shiyang River
摘要:
The grain size composition and distribution of river sediments are important for understanding regional geomorphological evolution, source-sink processes and drainage ecology. The Shiyang River basin, an inland river system in northwestern China, provides an environmental context within which to investigate the relationship between sediment particle size and environmental factors. Based on the analysis of the grain size characteristics of modern riverbed sediments, basin geomorphological parameters and lithology, it is found that the median grain size (Md) of river sediments shows a decrease trend from upstream to downstream in the basin. One of the tributaries named the Jinta River shows an obvious downstream fining trend (exponentially decreasing) of Md, which is related to the old geomorphological development stages and relatively homogeneous lithology in the basin. The downstream fining trend of Md along the Xiying River, another tributary, shows complex fluctuations, which might be affected by the tectonically active, young geomorphic development stage, complex lithology of the basin, and the sediment confluence of tributaries. The gravel-sand transition zone occurs in the plain section of the river about 28 km out of the mountain, which is related to the combination of regional geomorphological features, river morphology and hydraulic sorting.
期刊:
Arabian Journal for Science and Engineering,2023年48(4):5683-5683 ISSN:2193-567X
通讯作者:
Tang Wei
作者机构:
[Yang Yalan; Tang Wei] Hunan City Univ, Sch Humanities, Yiyang 413000, Peoples R China.
通讯机构:
[Tang Wei] S;School of Humanities, Hunan City University, Yiyang, China
关键词:
E-commerce;Deep learning network;Data dissemination;Logistic;Cyber security;Integrated learning system based chain management system
摘要:
Recently, the rapid development of e-commerce faces various challenges in information maintenance during online transactions and purchases. Presently, server error and security threats are an interactive method of payment; inconsistent data dissemination issues and prolonged customer waiting time during online purchase and transaction lead to several concerns based on supply chain management during the delivery of products. An essential component of e-commerce is the online transaction portal to ensure specific transactions with conflicts free and ensuring cyber security. Hence, this research develops a deep logistic learning framework (DLLF) to minimize computational time and improve data dissemination accuracy during an online transaction. Furthermore, the DLLF model has been designed based on deep logistic and sampled structure using a controlled network approach and integrated learning system to minimize the computational time and improve accuracy in maintaining customer data. Simulation analysis shows that user behaviors proposed framework analysis improves precision and minimizes computation time during the online purchase effectively with cyber security. The experimental results show DLLF has high efficiency (95.1%), enhanced customer satisfaction (92.6%), less error rate (21.4%), performance rate (94.3%), improved data prediction (91.2%), cost-effectiveness (94.5%), overall production (93.6%) when compared to other 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.