Guest electron-accepting polymer doping enables green solvent-processed all-polymer solar cells with 16.37% efficiency
作者：
Li, Zhenye;Liang, Yingfang;Chen, Lin;Chen, Jian;Peng, Feng;...
期刊：
Chemical Engineering Journal ,2023年452:139228 ISSN：1385-8947
通讯作者：
Li, Zhenye(lizhenye@usc.edu.cn)
作者机构：
[Li, Zhenye] Univ South China, Coll Mech Engn, Hengyang 421001, Peoples R China.;[Ying, Lei; Peng, Feng] South China Univ Technol, Inst Polymer Optoelect Mat & Devices, State Key Lab Luminescent Mat & Devices, Guangzhou 510640, Peoples R China.;[Liang, Yingfang] Univ South China, Hengyang 421001, Peoples R China.;[Li, Zhenye; Chen, Lin; Chen, Jian] Hunan Dahe New Mat Co Ltd, Hengyang 421001, Peoples R China.
通讯机构：
[Zhenye Li] C;[Lei Ying] I;College of Mechanical Engineering, University of South China, Hengyang 421001, China<&wdkj&>Hunan Dahe New Materials Co., Ltd., Hengyang 421001, China<&wdkj&>Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China
关键词：
All-polymer solar cells;Non-halogenated solvent;Polymer doping;Stability
摘要：
The development of polymerized small molecule acceptors (PSMA) has pushed all-polymer solar cells (all-PSCs) to break through power conversion efficiency (PCE) of 16–17%. However, these PCEs are obtained by halogenated solvents processing, which will cause serious harm to the environment and human health. To make the PSMA-based all-PSCs suitable for non-halogenated solvent processing, we introduced PZT into a typical high-efficiency all-PSCs system based on PBDB-T:PYF-T, to improve the solubility of PYF-T in non-halogenated solvent toluene (TL). PZT and PYF-T worked in an alloy-like model due to excellent miscibility induced by the similar molecular structure. A top PCE of 16.37% was obtained for TL-processed all-PSCs based on PBDB-T:PYF-T:PZT, which represented the highest PCE value for all-PSCs processed by non-halogenated solvents. In addition, the doping of PZT can significantly improve the ambient processing stability, photo-stability and thermal-stability of TL-processed all-PSCs, proving that polymer doping strategy enables all-PSCs compatible for practical applications. © 2022 Elsevier B.V.
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英文
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Revealing the microstructural evolution and its influence on mechanical properties of heterostructured steel fabricated by laser melting deposition
作者：
Liu, Hao;Wu, Wenxing;Yang, Tong;Qiu, Changjun;Chen, Pinghu
期刊：
Journal of Materials Research and Technology ,2023年24:4935-4944 ISSN：2238-7854
通讯作者：
Chen, PH
作者机构：
[Liu, Hao; Qiu, Changjun] Univ South China, Sch Resource Environm & Safety Engn, Hengyang 421001, Peoples R China.;[Wu, Wenxing; Qiu, Changjun] Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.;[Yang, Tong; Qiu, Changjun] Univ South China, Coll Mech Engn, Hengyang 421001, Peoples R China.;[Chen, Pinghu] Shenzhen Univ, Coll Mechatron & Control Engn, Shenzhen 518060, Peoples R China.;[Chen, PH] Shenzhen Univ, Coll Mechatron & Control Engn, Shenzhen 518060, Peoples R China.
通讯机构：
[Chen, PH ] ;Shenzhen Univ, Coll Mechatron & Control Engn, Shenzhen 518060, Peoples R China.
关键词：
3D printing;Deposition;Economic and social effects;Elongation;Maraging steel;Melting;Microstructural evolution;Strengthening (metal);Tensile strength;Thermal stress;% reductions;Ageing treatments;Heterostructured material;Laser melting deposition;Nanoscale intermetallic compounds;Second phase strengthening;Solution-aging;Strengthening mechanisms;Ultimate tensile strength;Variable ratio;Powders
摘要：
A series of heterostructured materials with variable ratio of 316 powders in 18Ni300 powders were prepared by laser melting deposition (LMD). The microstructural evolution and its influence on tensile features were explored before/after aging treatment or solution-aging treatment. The results indicated that the fraction of γ phase was increased gradually with increasing 316SS, and dislocation caused by the deformation could be migrated and annihilated within the region of γ phase, second phase strengthening could contribute to excellent elongation for 18Ni300 maraging steel. The elongation of the AF4 sample was 235.2% higher than that of the AF0 sample when a 37.5% reduction in the ultimate tensile strength occurred. In addition, thermal stress could exist in the as-cladded sample, an appropriate heat treatment could release the thermal stress and precipitate nanoscale intermetallic compound. Their synergistic effect could contribute to overcoming the strength-elongation trade-off. A relatively ideal sample, a discontinuous γ phase surrounded by α phase, which displayed high strength of 1678.4 MPa with high elongation of 10.9% after solution-aging treatment. Compared with laser cladded 18Ni300 maraging steel, a 41.7% increment in the elongation was obtained at the cost of 11.3% reduction in ultimate tensile strength. © 2023 The Author(s)
语种：
英文
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Experimental Investigation of Cobalt Deposition on 304 Stainless Steel in Borated and Lithiated High-Temperature Water
作者：
Deng, Jian;Lei, Jieheng;Wang, Guolong;Zhong, Lin;Zhao, Mu;...
期刊：
Materials ,2023年16(10):3834- ISSN：1996-1944
通讯作者：
Lei, ZY
作者机构：
[Lei, Zeyong; Deng, Jian; Lei, ZY; Zhong, Lin] Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.;[Wang, Guolong; Deng, Jian] Univ South China, Sch Mech Engn, Hengyang 421001, Peoples R China.;[Lei, Jieheng] Univ South China, Sch Elect Engn, Hengyang 421001, Peoples R China.;[Zhao, Mu] China Nucl Ind 24 Construct Co Ltd, Beijing 102400, Peoples R China.
通讯机构：
[Lei, ZY ] U;Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.
关键词：
Austenitic stainless steel;Glow discharges;Inductively coupled plasma;Ion exchange;Ions;Iron compounds;Nuclear fuels;Nuclear power plants;Optical emission spectroscopy;Pressurized water reactors;Scanning electron microscopy;Steel corrosion;X ray photoelectron spectroscopy;304 stainless steel;Cobalt deposition;Cobalt ion;Corrosion products;Experimental investigations;High-temperature water;Pressurised water reactor;Primary loop;Spinel;Stainless steel surface;Deposition
摘要：
The radioactive corrosion products 58Co and 60Co in the primary loops of pressurized water reactors (PWRs) are the main sources of radiation doses to which workers in nuclear power plants are exposed. To understand cobalt deposition on 304 stainless steel (304SS), which is the main structural material used in the primary loop, the microstructural characteristics and chemical composition of a 304SS surface layer immersed for 240 h in borated and lithiated high-temperature water containing cobalt were investigated with scanning electron microscopy (SEM), X-ray diffraction (XRD), laser Raman spectroscopy (LRS), X-ray photoelectron spectroscopy (XPS), glow discharge optical emission spectrometry (GD-OES), and inductively coupled plasma emission mass spectrometry (ICP-MS). The results showed that two distinct cobalt deposition layers (an outer layer of CoFe2O4 and an inner layer of CoCr2O4) were formed on the 304SS after 240 h of immersion. Further research showed that CoFe2O4 was formed on the metal surface by coprecipitation of the iron preferentially dissolved from the 304SS surface with cobalt ions from the solution. The CoCr2O4 was formed by ion exchange between the cobalt ions entering the metal inner oxide layer and (Fe, Ni) Cr2O4. These results are useful in understanding cobalt deposition on 304SS and have a certain reference value for exploring the deposition behavior and mechanism of radionuclide cobalt on 304SS in the PWR primary loop water environment. © 2023 by the authors.
语种：
英文
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Electrochemical activation strategy enabled ammonium vanadate cathodes for all-climate zinc-ion batteries
作者：
Fang, Kan;Liu, Yi-Lin;Chen, Peng;Zhang, Heng;Fang, Daliang;...
期刊：
Nano Energy ,2023年114:108671 ISSN：2211-2855
通讯作者：
Zhang, Hua-Yu;Wang, GG;Yang, HY
作者机构：
[Wei, Zhan; Fang, Kan; Zhang, Hua-Yu; Wang, Gui-Gen; Zhang, HY; Ding, Ling] Harbin Inst Technol Shenzhen, Sch Mat Sci & Engn, Guangdong Prov Key Lab Semicond Optoelect Mat & In, Shenzhen 518055, Peoples R China.;[Liu, Yi-Lin] Univ South China, Sch Mech Engn, Hengyang 421001, Hunan, Peoples R China.;[Chen, Peng] Yangzhou Univ, Inst Innovat Mat & Energy, Fac Chem & Chem Engn, Yangzhou 225009, Jiangsu, Peoples R China.;[Zhang, Heng] Suzhou Univ Sci & Technol, Sch Mat Sci & Engn, Suzhou 215009, Peoples R China.;[Yang, Hui Ying; Yang, HY; Fang, Daliang] Singapore Univ Technol & Design, Pillar Engn Prod Dev, 8 Somapah Rd, Singapore 487372, Singapore.
通讯机构：
[Yang, HY ] S;[Wang, GG ; Zhang, HY] H;Harbin Inst Technol Shenzhen, Sch Mat Sci & Engn, Guangdong Prov Key Lab Semicond Optoelect Mat & In, Shenzhen 518055, Peoples R China.;Singapore Univ Technol & Design, Pillar Engn Prod Dev, 8 Somapah Rd, Singapore 487372, Singapore.
关键词：
Zinc-ion batteries;Electrochemical activation;Ammonium vanadate;Large areal capacity;All-climate
摘要：
Aqueous zinc-ion batteries (ZIBs) have attracted significant attention for grid-scale energy applications due to their low cost, intrinsic safety, and environmental friendliness. However, the energy density of current ZIBs is impeded by unsatisfactory performance of cathodes, due to their limited areal capacity and low active material loading, especially at extreme environments. Herein, an electrochemical activation strategy is put forward to build high energy density ZIBs by designing a flexible cathode composed of NH4+ pillared ammonium vanadate nanosheets on carbon cloth (NVMCE@CC). The electrochemical activation process with high anodic potential (> 1.5 V vs. Zn2+/Zn) guarantees the effective conversion of low-valent to high-valent vanadium and promotes the utilization of large amounts of vanadium elements in the NVMCE@CC composite. Meanwhile, the pillared NH4+ ions expand the interlayer spacing and enhance the structural integrity through the hydrogen bonding between NH4+ and V-O framework. Consequently, the activated NVMCE@CC cathode with a high mass-loading of ∼5.2 mg cm−2 delivers large areal capacity (∼1.74 mAh cm−2 at 1 mA cm−2) and superior cycling stability (capacity retention of 72.1% after 1500 cycles). Importantly, the flexible cathode shows admirable capacities of 0.52 mAh cm−2 at 60 °C and 0.55 mAh cm−2 at − 10 °C, respectively. Moreover, the NVMCE@CC//Zn@CC quasi-solid-state battery demonstrates excellent safety performance and performs well in extreme situations, including bending, cutting, hammering, and washing. This work provides enlightenment for the development of large-areal-capacity vanadium-based cathode materials for practical ZIBs. © 2023 Elsevier Ltd
语种：
英文
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Research on the technology rule of high-power laser pretreatment of granite slitting
作者：
Li, Can;Liu, Lie;Han, Lianghua
期刊：
Journal of Physics: Conference Series ,2023年2419(1):012048 ISSN：1742-6588
通讯作者：
Liu, Lie(Reseek206@163.com)
作者机构：
[Li, Can; Liu, Lie; Han, Lianghua] School of Mechanical Engineering, University of South China, Hunan, Hengyang;421001, China;[Li, Can; Liu, Lie; Han, Lianghua] 421001, China
摘要：
<jats:title>Abstract</jats:title>
<jats:p>In order to provide new pretreatment damage morphology for TBM rock breaking, the author used a ten-thousand-watt laser beam to perform cutting experiments on granite. Different laser power and cutting speed were set, and the cutting depth, width, rock removal and mass ratio were measured, calculated and analyzed. The experimental results showed that the laser power increased, the depth of cut, width and rock removal increased, and the mass ratio decreased; the cutting speed increased, the depth of cut, width and rock removal decreased, and the mass ratio increased. Under this experimental condition, the cutting effect is better when the laser power is 12kW and the cutting speed is 6mm/s.</jats:p>
语种：
英文
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Microstructure refinement and mechanical properties enhancement of wire and arc additively manufactured 6061 aluminum alloy using friction stir processing post-treatment
作者：
He, Peng;Bai, Xingwang;Zhang, Haiou
期刊：
Materials Letters ,2023年330:133365 ISSN：0167-577X
通讯作者：
Bai, Xingwang(pancard@126.com)
作者机构：
[Bai, Xingwang; He, Peng] Univ South China, Sch Mech Engn, Hengyang 421001, Peoples R China.;[Zhang, Haiou] Huazhong Univ Sci & Technol, Sch Mech Sci & Engn, Wuhan 430074, Peoples R China.
通讯机构：
[Xingwang Bai] S;School of Mechanical Engineering, University of South China, Hengyang 421001, China
关键词：
3D printers;Additives;Aluminum alloys;Friction;Friction stir welding;Porosity;Quality assurance;Research laboratories;Tensile strength;6061 aluminum alloys;Average grain size;Friction stir processing;Mechanical properties enhancements;Microstructure refinement;Porosity reduction;Post treatment;Refined microstructure;Ultimate tensile strength;Vertical direction;Microstructure
摘要：
Microstructure refinement and mechanical properties enhancement were achieved by utilizing friction stir processing (FSP) as post-treatment to 6061 aluminum alloy fabricated by wire and arc additive manufacturing (WAAM). FSP led to a significant microstructure refinement and porosity reduction. The average grain size decreased from approximately 128 µm to about 5 µm. Because of the refined microstructure and the reduced porosity, the average microhardness, yield strength, and ultimate tensile strength increased by 31.5 %, 23.3 % and 6.0 %, respectively. The elongation difference between the horizontal and vertical direction was reduced from 4.5 % to 1.4 %. The properties anisotropy caused by delamination was weakened by the FSP. This work provides a valid option for the quality assurance of the WAAM process of aluminum alloys. © 2022 Elsevier B.V.
语种：
英文
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2D Nanomaterial Supported Single‐Metal Atoms for Heterogeneous Photo/Electrocatalysis
作者：
Yan, Cheng;Liu, Yi-Lin;Zeng, Qingyi;Wang, Gui-Gen;Han, Jie-Cai
期刊：
Advanced Functional Materials ,2023年33(5):2210837- ISSN：1616-301X
通讯作者：
Yan, Cheng(cyan003@e.ntu.edu.sg);Liu, Yi-Lin(liuyilin@usc.edu.cn);Wang, Gui-Gen(wangguigen@hit.edu.cn)
作者机构：
[Liu, Yi-Lin; Yan, Cheng; Zeng, Qingyi] Univ South China, Coll Mech Engn, Hengyang 421001, Peoples R China.;[Wang, Gui-Gen; Yan, Cheng; Han, Jie-Cai] Harbin Inst Technol Shenzhen, Sch Mat Sci & Engn, Shenzhen Key Lab Adv Mat, Shenzhen 518055, Peoples R China.;[Yan, Cheng] Univ Sydney, Fac Sci, Sch Chem, Sydney 2006, Australia.;[Han, Jie-Cai] Harbin Inst Technol, Natl Key Lab Sci & Technol Adv Composites Special, Harbin 150080, Peoples R China.
通讯机构：
[Cheng Yan; Yi-Lin Liu] C;[Gui-Gen Wang] S;College of Mechanical Engineering, University of South China, Hengyang, 421001 P. R. China<&wdkj&>Shenzhen Key Laboratory for Advanced Materials, School of Materials Science and Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen, 518055 P. R. China<&wdkj&>School of Chemistry, Faculty of Science, The University of Sydney, Sydney, 2006 Australia<&wdkj&>College of Mechanical Engineering, University of South China, Hengyang, 421001 P. R. China<&wdkj&>Shenzhen Key Laboratory for Advanced Materials, School of Materials Science and Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen, 518055 P. R. China
关键词：
2D nanomaterials;electrocatalyses;operando characterizations;photocatalyses;single-atom catalysts
摘要：
This review article presents advances in 2D nanomaterial supported single metal atom catalysts (SACs) toward photo/electrocatalysis, with the special emphasis on the superiorities of 2D nanosheets as host materials. Advanced ex/in situ microscopic and spectroscopic approaches as well as rational design strategies of 2D‐SACs, are comprehensively summarized. The future challenges and opportunities on the 2D nanosheets‐supported SACs for photo/electrocatalysis are highlighted. Abstract Single‐atom catalysts (SACs) attract intensive attention owing to their unmatched catalytic activities and high atom utilization. Besides metal species themselves, the substrates play a key role for the improvement of their catalytic performance by optimizing metal–support interactions and coordination structures. In the past years, various 2D nanomaterials have been employed to anchor single metal atoms for renewable energy technologies and other important industrial processes. Tremendous progress has been achieved in the development of 2D supported SACs for advanced energy conversion reactions. This article provides a comprehensive and critical review of up‐to‐date advances in the field of 2D supported SACs. The state‐of‐the‐art characterizations including ex/in situ microscopic and spectroscopic techniques are summarized with the emphasis on their specific superiorities in identifying the reactive sites and reaction mechanisms, combined with theoretical calculations and experimental results. A brief overview of various reactions including hydrogen evolution reaction (HER), oxygen evolution reaction (OER), two‐electron oxygen reduction reaction (2e‐ORR), carbon dioxide reduction (CO2RR), and nitrogen reduction reaction (NRR) under the framework of electrocatalysis and photocatalysis, is presented on basis of versatile 2D nanomaterial supports. Last, the key challenges and opportunities in this rising field are highlighted.
语种：
英文
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Tunable topological interface states and resonance states of surface waves based on the shape memory alloy
作者：
Huo, Shao-Yong;Yao, Long-Chao;Hsieh, Kuan-Hong;Fu, Chun-Ming;Chiu, Shih-Chia;...
期刊：
中国物理B ,2023年32(3):034303 ISSN：1674-1056
作者机构：
[Fu, Chun-Ming; Huo, Shao-Yong; Deng, Jian; Yao, Long-Chao] Univ South China, Coll Mech Engn, Hengyang 421001, Peoples R China.;[Gong, Xiao-Chao; Hsieh, Kuan-Hong; Chiu, Shih-Chia] 1MORE INC, Shenzhen 518000, Peoples R China.
关键词：
tunable topological interface state;Rayleigh wave;alterable mode width;topological phononic crystals;shape memory alloys
摘要：
Topological interface state (TIS) of elastic wave has attracted significant research interest due to its potential prospects in strengthening acoustic energy and enhancing the signal accuracy of damage identification and quantification. However, previous implementations on the interface modes of surface waves are limited to the non-adjustable frequency band and unalterable mode width. Here, we demonstrate the tunable TIS and topological resonance state (TRS) of Rayleigh wave by using a shape memory alloy (SMA) stubbed semi-infinite one-dimensional (1D) solid phononic crystals (PnCs), which simultaneously possesses the adjustable mode width. The mechanism of tunability stems from the phase transformation of the SMA between the martensite at low temperature and the austenite at high temperature. The tunable TIS of Rayleigh wave is realized by combining two bandgap-opened PnCs with different Zak phases. The TRS with adjustable mode width is achieved in the heterostructures by adding PnCs with Dirac point to the middle of two bandgap-opened PnCs with different Zak phases, which exhibits the extraordinary robustness in contrast to the ordinary Fabry-Pérot resonance state. This research provides new possibilities for the highly adjustable Rayleigh wave manipulation and find promising applications such as tunable energy harvesters, wide-mode filters, and high-sensitivity Rayleigh wave detectors. © 2023 Chinese Physical Society and IOP Publishing Ltd.
语种：
英文
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Controllable fabrication of hierarchical bubble-like Co3O4 tubes with enhanced trimethylamine sensing performance
作者：
Hu, Jie;Xiong, Xueqing;Guan, Wangwang;Long, Haizhu
期刊：
Sensors and Actuators B-Chemical ,2023年389:133886 ISSN：0925-4005
通讯作者：
Hu, J
作者机构：
[Guan, Wangwang; Xiong, Xueqing; Hu, Jie] Univ South China, Sch Mech Engn, Hengyang 421001, Peoples R China.;[Long, Haizhu] Xiangtan Univ, Sch Mat Sci & Engn, Xiangtan 411105, Peoples R China.
通讯机构：
[Hu, J ] U;Univ South China, Sch Mech Engn, Hengyang 421001, Peoples R China.
关键词：
Hierarchical structure;ZIF-67 intermediate;TEA sensing;Sensing mechanism
摘要：
To facilitate the effective monitoring of human health and environmental quality, it is essential to develop high-quality gas sensors for trimethylamine (TEA) with stable sensing sensitivity and low resistance fluctuations in a wide range of humid atmospheres. To this end, a novel Bubble-like Co3O4 tube was fabricated through a ZIF-67 intermediate-assisted thermal decomposition strategy, and its surface morphology and nanostructure were comprehensively investigated. Furthermore, a systematic comparison of the gas sensing properties between Rod-like Co3O4 and Bubble-like Co3O4 was also conducted. The results demonstrated that the introduction of ZIF-67 intermediate not only decreased the baseline resistance of the Bubble-like Co3O4 sensor but also enhanced its gas-sensing performance. Specifically, the response value of the sensor fabricated using Bubble-like Co3O4 for detecting 100 ppm TEA at 180 °C was around ten times higher than that of the Rod-like Co3O4 sensor, while achieving a low detection limit of 55 ppb. Furthermore, the gas sensor exhibited excellent selectivity and anti-humidity stability, with negligible variation in response value even after 30 days, retaining approximately 98 % of the initial value. This remarkable sensing-performance can be attributed to several factors, including the large specific surface area, abundant oxygen vacancies, and efficient Co3+/Co2+ catalyzing. Overall, this work sheds new light on the rational design of high-performance TEA sensing materials for practical applications. © 2023 Elsevier B.V.
语种：
英文
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Research progress and Prospect of Laser Cladding Technology
作者：
Li, Changqi
期刊：
Journal of Physics: Conference Series ,2023年2419(1):012049 ISSN：1742-6588
通讯作者：
Li, Changqi(791491102@qq.com)
作者机构：
[Li, Changqi] School of Mechanical Engineering, University of South China, Hunan, Hengyang;421001, China;[Li, Changqi] 421001, China
摘要：
<jats:title>Abstract</jats:title>
<jats:p>Laser cladding technology is an advanced material surface modification technology, which has the advantages of a small dilution rate, a dense microstructure of the cladding layer, a good combination between coating and substrate, and no pollution of the working environment. The research progress of laser cladding is reviewed from three aspects: background types, basic principles, and research status. In the background category, the preset coating method and synchronous powder feeding method used in laser cladding technology are described. The research status of laser cladding technology is summarized from the aspects of cladding material, performance, and industrial application. Finally, some suggestions are put forward to obtain the cladding layer with no crack and good mechanical properties, and more technologies and laser cladding technology are expected to be combined in the future.</jats:p>
语种：
英文
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AI-Driven and MEC-Empowered Confident Information Coverage Hole Recovery in 6G-Enabled IoT
作者：
Xia, Yunzhi;Deng, Xianjun;Yi, Lingzhi;Yang, Laurence T.;Tang, Xiao;...
期刊：
IEEE TRANSACTIONS ON NETWORK SCIENCE AND ENGINEERING ,2023年10(3):1256-1269 ISSN：2327-4697
通讯作者：
Deng, XJ
作者机构：
[Deng, Xianjun; Xia, Yunzhi; Yang, Laurence T.] Huazhong Univ Sci & Technol, Sch Cyber Sci & Engn, Wuhan 430074, Peoples R China.;[Yi, Lingzhi] Zhongnan Univ Econ & Law, Sch Informat & Safety Engn, Wuhan 430073, Peoples R China.;[Tang, Xiao] Univ South China, Sch Mech Engn, Hengyang 421009, Peoples R China.;[Zhu, Chenlu] Hubei Chutian Intelligent Transportat Co Ltd, Wuhan 430074, Peoples R China.;[Tian, Zhongping] Wasion Grp Co Ltd, Changsha 410205, Peoples R China.
通讯机构：
[Deng, XJ ] H;Huazhong Univ Sci & Technol, Sch Cyber Sci & Engn, Wuhan 430074, Peoples R China.
关键词：
6G mobile communication;Internet of Things;Maintenance engineering;Q-learning;Reliability;Energy consumption;Computational modeling;6G Internet of Things (IoT);coverage hole (CHs);confident information coverage model (CIC);mobile edge computing (MEC)
摘要：
With the development of 6G, a series of ultra-reliable intelligent IoT applications have been promoted, which puts forward higher requirements for the security and reliability of networks. Coverage Holes (CHs) pose great challenges to the network coverage reliability, and it is essential to repair CHs quickly and effectively. In this paper, we focus on the problem of CHs recovery of 6G IoT based on Mobile Edge Computing (MEC) and Artificial Intelligence (AI) to ensure reliable coverage. A Confident Information Coverage Hole Recovery Algorithm (CICHRA) is proposed based on the fusion model of the disc model and the confident information model, which takes advantage of the spatial correlation. The mobile edge node uses the utility to guide its movement, and the CHs are recovered by repeated games based on Q-learning. Furthermore, an Improved Confident Information Coverage Hole Recovery Algorithm (I-CICHRA) is proposed to enhance recovery performance and reduce time complexity. The I-CICHRA makes edge nodes’ movement more directional and accurate, thus improving repair efficiency. A series of simulation comparisons with the Distributed Payoff-based Q-learning Algorithm (DPQA) indicate that the proposed algorithms have better performance in overall coverage, iteration times, energy consumption, and energy efficiency. © 2022 IEEE.
语种：
英文
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Design and construction of core-shelled Co3O4-CoFe2O4 heterojunction for highly sensitive and selective detection of ammonia
作者：
Hu, Jie;Xiong, Xueqing;Guan, Wangwang;Chen, Yong;Long, Haizhu
期刊：
Chemical Engineering Journal ,2023年452:139346 ISSN：1385-8947
通讯作者：
Hu, Jie(hujie_gtq@163.com)
作者机构：
[Guan, Wangwang; Xiong, Xueqing; Hu, Jie; Chen, Yong] Univ South China, Sch Mech Engn, Hengyang 421001, Peoples R China.;[Long, Haizhu] Xiangtan Univ, Sch Mat Sci & Engn, Xiangtan 411105, Peoples R China.
通讯机构：
[Jie Hu] S;School of Mechanical Engineering, University of South China, Hengyang 421001, China
关键词：
Ammonia sensor;Core-shell structure;Gas sensing;Long-term stability
摘要：
In this study, the fabrication process and the gas sensing performance toward ammonia of core-shelled Co3O4-CoFe2O4 heterojunction composites with the abundant mesoporous structures were presented detailedly. The hierarchical Co3O4-CoFe2O4 was prepared by using Fe-Co glycerate as a precursor combined with a subsequent thermolysis method. The well-designed core-shelled heterojunction architecture was investigated through SEM and TEM. Apparently, the internal and external structure of the glycerate-derived sensing materials can be efficiently regulated by adjusting the molar ratio of the Fe and Co in the precursor. It was worth pointing out that the core-shelled heterojunction structure possessed a large specific surface area (198.6 m2/g), which not only can provide more active sites in both interior and exterior of the composites sphere, but also accelerate absorption-penetration efficiency of gas molecules. Compared with other prepared nanoparticles and hollow spheres, the sensor fabricated by Co3O4-CoFe2O4 with a core–shell structure revealed the best sensing characteristics, and the response toward 100 ppm ammonia at 220 °C was as high as 35. Moreover, it also showed excellent selectivity and long-term stability. These admirable advancements can be ascribed to the synergistic effect of unique core–shell architecture and p-p heterojunction. This work may offer a promising strategy to realize the practical application of Co3O4-CoFe2O4 p-p heterojunction in ammonia detection. © 2022 Elsevier B.V.
语种：
英文
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Modeling and Optimization Methods for Charging Route Planning and Sensor Battery Capacity Minimization for Wireless Rechargeable Sensor Networks
作者：
Zhao, Wenhao;Xiang, Suji;Shu, Ziqing;Chen, Zeliang;Zhang, Jing
期刊：
Proceedings of SPIE - The International Society for Optical Engineering ,2023年12759:69 ISSN：0277-786X
通讯作者：
Zhao, Wenhao(z1823101074@163.com)
作者机构：
[Zhao, Wenhao; Chen, Zeliang] College of Mechanical Engineering, University of South China, Hunan, Hengyang;421001, China;[Xiang, Suji; Shu, Ziqing] School of Economics, Management and Law, University of South China, Hunan, Hengyang;[Zhang, Jing] College of Chemistry and Chemical Engineering, University of South China, Hunan, Hengyang;[Zhao, Wenhao; Xiang, Suji; Shu, Ziqing; Chen, Zeliang; Zhang, Jing] 421001, China
摘要：
The wireless rechargeable sensor network mainly consists of a data processing unit, a sensor (data acquisition unit), and a mobile charger (energy supply unit). For the wireless rechargeable sensor network to work properly, the mobile charger needs to charge the sensors periodically through the route given by the data processing unit, but the mobile charger incurs unnecessary energy loss on the charging journey. This paper discusses the problem of route planning and the minimum capacity of sensor batteries for single versus multiple mobile chargers. First, the TSP and MTSP problems of minimum energy consumption of mobile chargers over the distance are solved by modeling them with Monte Carlo optimization simulated annealing algorithm, and improved genetic algorithm, respectively. Then, the problem is further transformed into a linear programming and multi-objective optimization model to solve for the minimum capacity of the battery. In addition, computational experiments using the LKH algorithm and CA learning methods are conducted in this paper to propose optimization scenarios for the route planning model. © 2023 SPIE.
语种：
英文
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Study on Microstructure and Mechanical Properties of TC4/AZ31 Magnesium Matrix Nanocomposites
作者：
Chen, Yong;Yao, Yuan;Han, Shengli;Feng, Xiaowei;Luo, Tiegang;...
期刊：
Materials ,2023年16(3):1139- ISSN：1996-1944
通讯作者：
Luo, Tiegang(luotiegang@126.com);Zheng, Kaihong(13602721690@163.com)
作者机构：
[Yao, Yuan; Chen, Yong] Univ South China, Coll Mech Engn, Hengyang 421101, Peoples R China.;[Feng, Xiaowei; Luo, Tiegang; Han, Shengli; Zheng, Kaihong] Guangdong Acad Sci, Inst New Mat, Natl Engn Res Ctr Powder Met Titanium & Rare Met, Guangdong Prov Key Lab Met Toughening Technol & Ap, Guangzhou 510650, Peoples R China.
通讯机构：
[Tiegang Luo; Kaihong Zheng] A;Authors to whom correspondence should be addressed.<&wdkj&>Guangdong Provincial Key Laboratory of Metal Toughening Technology and Application, Institute of New Materials, Guangdong Academy of Sciences, National Engineering Research Center of Powder Metallurgy of Titanium & Rare Metals, Guangzhou 510650, China
关键词：
Aluminum alloys;Grain size and shape;Magnesium alloys;Metallic matrix composites;Scanning electron microscopy;Spark plasma sintering;Tensile strength;Textures;Titanium compounds;AZ31;AZ31 magnesium;Grains refinement;Magnesium matrix composite;Magnesium matrix nanocomposites;matrix;Metal matrix;Microstructures and mechanical properties;Nano powders;TC4 particle;Grain refinement
摘要：
In the field of metal matrix composites, it is a great challenge to improve the strength and elongation of magnesium matrix composites simultaneously. In this work, xTC4/AZ31 (x = 0.5, 1, 1.5 wt.%) composites were fabricated by spark plasma sintering (SPS) followed by hot extrusion. Scanning electron microscopy (SEM) showed that nano-TC4 (Ti-6Al-4V) was well dispersed in the AZ31 matrix. We studied the microstructure evolution and tensile properties of the composites, and analyzed the strengthening mechanism of nano-TC4 on magnesium matrix composites. The results showed that magnesium matrix composites with 1 wt.%TC4 had good comprehensive properties; compared with the AZ31 matrix, the yield strength (YS) was increased by 20.4%, from 162 MPa to 195 MPa; the ultimate tensile strength (UTS) was increased by 11.7%, from 274 MPa to 306 MPa, and the failure strain (FS) was increased by 21.1%, from 7.6% to 9.2%. The improvement in strength was mainly due to grain refinement and good interfacial bonding between nano-TC4 and the Mg matrix. The increase in elongation was the result of grain refinement and a weakened texture. © 2023 by the authors.
语种：
英文
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Frequency-selective valley edge routing of elastic wave in topological phononic crystals with different symmetries
作者：
Yao, Long-chao;Hsieh, Kuan-Hong;Chiu, Shih-Chia;Li, Hong-kang;Huo, Shao-yong;...
期刊：
JOURNAL OF PHYSICS-CONDENSED MATTER ,2023年35(20):205701 ISSN：0953-8984
通讯作者：
Chiu, Shih-Chia(gary.sc.chiu@tiinlab.com);Huo, Shao-Yong(shaoyhuo@hnu.edu.cn);Fu, Chun-Ming(fuchunming@hnu.edu.cn)
作者机构：
[Li, Hong-kang; Yao, Long-chao; Huo, Shao-yong; Fu, Chun-ming] Univ South China, Coll Mech Engn, Hengyang 421001, Peoples R China.;[Hsieh, Kuan-Hong; Chiu, Shih-Chia] 1MORE INC, Shenzhen 518000, Peoples R China.
通讯机构：
[Shih-Chia Chiu] 1;[Shao-yong Huo; Chun-ming Fu] C;College of Mechanical Engineering, University of South China, Hengyang 421001, People's Republic of China<&wdkj&>1MORE INC, Shenzhen 518000, People's Republic of China
关键词：
Crystals;Energy gap;Interface states;Landforms;Phonons;Topology;Wave propagation;Boundary structure;Edge state;Excitation sources;Frequency selective routing;Frequency-selective;Phononic Crystal;Propagation direction;Propagation paths;Routings;Valley edge state;Elastic waves;article;excitation;simulation;ultrasound
摘要：
The control of propagation direction or path of edge states is difficult when the chirality of the excitation source and the boundary structures are determined. Here, we studied a frequency-selective routing for elastic wave based on two types of topological phononic crystals (PnCs) with different symmetries. By constructing multiple types of interfaces between different PnCs structures with distinct valley topological phases, the valley edge states of elastic wave could be realized at different frequencies in the band gap. Meanwhile, based on the simulation of topological transport, it is found that the routing path of elastic waves valley edge states highly depends on the operating frequency and the inputting port of the excitation source. By varying the excitation frequency, the transport path can be switched. The results provide a paradigm for the control of elastic wave propagation paths that could be employed for designing the frequency-dependent ultrasonic division devices. © 2023 IOP Publishing Ltd.
语种：
英文
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Advances in crack formation mechanism and inhibition strategy for ceramic additive manufacturing
作者：
Liu, Zhiwen;Ma, Changbao;Chang, Zhengxu;Yan, Ping;Li, Fazhi
期刊：
Journal of the European Ceramic Society ,2023年43(12):5078-5098 ISSN：0955-2219
通讯作者：
Li, FZ
作者机构：
[Liu, Zhiwen; Yan, Ping; Li, Fazhi; Ma, Changbao; Chang, Zhengxu] Univ South China, Coll Mech Engn, Hengyang 421001, Peoples R China.
通讯机构：
[Li, FZ ] U;Univ South China, Coll Mech Engn, Hengyang 421001, Peoples R China.
关键词：
Additives;Cams;Ceramic materials;Cracks;Sintering;Additive manufacturing process;Ceramic additives;Crack formation mechanisms;Distribution characteristics;Formation mechanism;Inhibition strategy;Macrocrack;Manufacturing IS;Micro and macro;Micro cracks;3D printing
摘要：
Crack formation is a common problem in ceramic additive manufacturing (CAM) process. In this paper, the forming characteristics of indirect ceramic additive manufacturing (DCAM) and direct ceramic additive manufacturing (IDCAM) technologies are comprehensively compared. The morphology and spatial distribution characteristics of micro and macro cracks in CAM are summarized. The crack formation mechanisms in different process stages of IDCAM, such as forming, sintering and cooling are analyzed and in DCAM are mainly discussed from the perspectives of stress distribution and energy release. The crack inhibition methods, including process parameters, auxiliary energy fields and material components are summarized comprehensively. The challenges and possible future trends of crack research in CAM are proposed. © 2023
语种：
英文
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Wire arc additive manufacturing of network microstructure (TiB+TiC)/ Ti6Al4V composites using flux-cored wires
作者：
Wang, Zhuorui;Bai, Xingwang;Que, Mingxin;Zhou, Xiangman
期刊：
Ceramics International ,2023年49(3):4168-4176 ISSN：0272-8842
通讯作者：
Bai, Xingwang(pancard@126.com)
作者机构：
[Bai, Xingwang; Wang, Zhuorui; Que, Mingxin] Univ South China, Sch Mech Engn, Hengyang 421001, Hunan, Peoples R China.;[Zhou, Xiangman] China Three Gorges Univ, Coll Mech & Power Engn, Yichang 443002, Hubei, Peoples R China.
关键词：
Wire arc additive manufacturing;Titanium matrix composite;Network microstructure;Flux-cored wires;Wear resistance
摘要：
Titanium matrix composites (TMCs) with ceramic particles exhibit higher hardness, strength, and wear resistance than those of titanium alloys. Wire arc additive manufacturing (WAAM) is a promising method for fabricating large TMC components owing to its high deposition rate and low production cost. In this study, a WAAM process using a flux-cored wire was developed to fabricate components of TiB plus TiC reinforced Ti6Al4V matrix composites. The network microstructure of the reinforcement was obtained through in-situ reactions induced by the B4C and C powders in the flux core. The formation mechanism of the network microstructure was discussed. The effect of the reinforcement fraction (5 and 10 wt%, hereinafter called 5 and 10 wt% samples) on the microstructure and wear resistance of the samples along the deposition direction were investigated. The results showed that the refined net-basket-dominated (αβ)-Ti matrix and stable network microstructure were formed in middle region owing to the introduction of the reinforcement. The microhardness increased by 23% and 35% when the reinforcement fractions were 5 and 10 wt%, respectively. The 10 wt% sample showed reduced wear performance because more cracks appeared as the result of the decreased ductility. © 2022 Elsevier Ltd and Techna Group S.r.l.
语种：
英文
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Formation mechanism and quantitative analysis of pores in Al2O3–ZrO2 ceramic different structures by laser additive manufacturing
作者：
Liu, Zhiwen;Ma, Changbao;Chang, Zhengxu;Zhao, Penghui;Zhang, Yi;...
期刊：
Ceramics International ,2023年49(10):16099-16109 ISSN：0272-8842
通讯作者：
Li, FZ
作者机构：
[Liu, Zhiwen; Li, Fazhi; Ma, Changbao; Chang, Zhengxu] Univ South China, Coll Mech Engn, Hengyang 421001, Peoples R China.;[Zhao, Penghui; Zhang, Yi] Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Peoples R China.;[Wu, Qiang] Qingdao Womens & Childrens Hosp, Dept Pediat Surg, Qingdao, Shandong, Peoples R China.
通讯机构：
[Li, FZ ] U;Univ South China, Coll Mech Engn, Hengyang 421001, Peoples R China.
关键词：
Laser additive manufacturing;Ceramic structure type;Pores
摘要：
Pores is one of the most defects during laser additive manufacturing of ceramic material. In this paper, different structures of Al2O3–ZrO2 ceramics are deposited by using powder-feeding laser additive manufacturing. The ceramic structures can be simplified into three typical structures: linear-type, face-type and body-type structure. The formation mechanism and quantitative analysis of pores in different ceramic structures are studied. The pores of ceramic structure is mainly divided into four types: intercrystalline pore, interlayer pore, intralayer pore and shrinkage pore. In the linear-type structure, the number of pores with the interval 0–1000 μm2 accounts for 98.8%, while the area of pores with the interval above 104 μm2 accounts for 58.33%. The remelting rate of deposition layer has great influence on the pores. The Marangoni convection changed from inflow mode to outflow mode, which leads to that bubbles have easily escape from molten pool. In the face-type structure, the number and area of pores at the interval 0–1000 μm2 account for 98.96% and 51.62%, respectively. Overlap ratio is the key factor affecting pore. Under the effects of the Marangoni convection and the overlap of deposition layer, the irregular pores are easily formed in the bottom of overlap region of deposition layer. The pores characteristic in the body-type structure is similar to that in linear-type structure. Due to the laser remelting and overlap phenomenon, the thermal accumulation effect is more obvious in the short time interval and continuous deposition process of body-type structure. Thus, the gas of molten pool can be easily escaped. This study can provide the theoretical basis for the suppression of pores in ceramic laser additive manufacturing. © 2023 Elsevier Ltd and Techna Group S.r.l.
语种：
英文
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Theoretical study on the hydrogenation of furfural for furfuryl alcohol production over low Ni modified Cu catalysts
作者：
Chen, Hao-Ze;Liu, Ji;Mi, Teng-Ge;Wu, Yang-Wen;Hu, Bin;...
期刊：
Applied Surface Science ,2023年613:156106 ISSN：0169-4332
通讯作者：
Liu, Ji(liujipower@126.com)
作者机构：
[Liu, Ji; Zhou, Xin-Yue; Hu, Bin; Zhang, Bing; Wu, Yang-Wen; Lu, Qiang; Chen, Hao-Ze] North China Elect Power Univ, Natl Engn Res Ctr New Energy Power Generat, Beijing 102206, Peoples R China.;[Mi, Teng-Ge] Univ South China, Sch Mech Engn, Hengyang 421001, Peoples R China.
通讯机构：
[Ji Liu; Qiang Lu] N;National Engineering Research Center of New Energy Power Generation, North China Electric Power University, Beijing 102206, PR China
关键词：
Cu catalyst;Furfural;Furfuryl alcohol;Hydrogenation;Ni doping
摘要：
Cu-based catalysts are efficient for the upgrading of biomass-derived furfural (FF) to produce furfuryl alcohol (FOL), and a low amount of Ni doping is promising to improve the catalytic performance. Herein, Cu (111), Cu7Ni (111), and Cu3Ni (111) catalyst models were constructed. Density functional theory (DFT) calculations were applied to explore the effects of Ni on the FF hydrogenation mechanism by analyzing the FF adsorption configurations, adsorption energies, electronic structures of the adsorbed FF and the catalyst surfaces, as well as reaction pathways and energy barriers of FF hydrogenation. Ni doping promotes the charge transfer between the catalyst surface and FF, thus enhancing the adsorption capacity of the catalyst. The H2 dissociation ability can also be enhanced by the Ni modification. In the initial hydrogenation process, the aldehyde group of the adsorbed FF is easy to hydrogenate and thus contributing to the selective production of FOL. With the increase of the Ni amount, the competitiveness of the hydroxyalkyl intermediate (F–CHOH) involved pathway increases according to the gradually widened energy barrier gaps among the competing pathways. All in all, the Cu3Ni (111) catalyst has the best hydrogenation activity with an energy barrier of 8.99 kJ/mol. © 2022 Elsevier B.V.
语种：
英文
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面向HY-1C卫星CZI陆地遥感图像的云检测方法研究
作者：
杨彬;郭金源;何鹏;叶小敏;刘建强
期刊：
遥感学报 ,2023年27(1):55-67 ISSN：1007-4619
通讯作者：
Liu, Jianqiang(jqliu@mail.nsoas.org.cn)
作者机构：
[杨彬; 郭金源] College of Electrical and Information Engineering, Hunan University, Changsha;410082, China;[何鹏] School of Mechanical Engineering, University of South China, Hengyang;421000, China;[叶小敏; 刘建强] National Satellite Ocean Application Service, Beijing
关键词：
海岸带成像仪;云检测;白度指数;非监督
摘要：
搭载在中国首颗海洋水色业务卫星HY-1C上的海岸带成像仪CZI （Coast Zone Imager）于2019年6月开始业务化运行,其获取的大量海岸带、陆地和海洋数据对于海洋灾害与环境监测研究具有重要意义。CZI对地观测受云干扰,影响数据的后续应用。现有的云检测算法大都基于RGB图像或者包含热红外的多光谱展开,对于HY-1C CZI这类RGB-近红外4个波段遥感图像研究较少。为此,本文提出了一种针对HY-1C CZI遥感图像的非监督遥感图像云检测方法。该方法包含训练样本选择、特征提取、支持向量机SVM （Support Vector Machine）分类和后处理这4个过程。在训练样本选择中,结合暗通道反射率、归一化植被指数和白度指数,提出了一种训练样本自动提取算法。该算法使用白度指数作为遥感图像细节信息提取数据源,并通过逐步细化过程精确提取样本。针对特征提取,选取图像的空—谱特征信息,包含反射率、光谱指数、纹理和结构特征,使云与非云区域的差异最大化。基于自动提取的训练样本及其特征描述,采用SVM对CZI遥感数据进行初分类,并在此基础上进行导向滤波、孔洞填充和几何判断后处理,以获取云检测结果。该算法的优势在于:（1）无需人工标注即可自动获取训练样本;（2）能够充分利用近红外波段信息。本文将该算法运用于植被、土壤、湿地和冰雪场景这4种典型场景中,并与目前流行的非监督云检测算法对比分析。相较于其他云检测算法,定性分析结果表明本文云检测结果与人工标注的云分布真实图具有较好的一致性;定量结果表明本文提出的算法在各个场景上都具有最低的错误率。通过以上对比分析,表明本文提出的云检测算法在不同的场景下识别结果都更加准确,证明了本文算法对于HY-1C CZI陆地遥感图像云检测的有效性。
语种：
中文
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