Crystal growth, superconductivity, and charge density wave of pristine and Pd-intercalated 2H-TaS2
作者：
Ni, Shunli;Zhou, Menghu;Lin, Zefeng;Ruan, Binbin;Li, Zhifeng;...
期刊：
PHYSICAL REVIEW B ,2023年108(7):075103 ISSN：2469-9950
通讯作者：
Ni, SL
作者机构：
[Ni, Shunli; Ni, SL; Xu, Zhenghua; Zou, Zhiwei; Li, Zhifeng] Univ South China, Sch Math & Phys, Hengyang 421001, Peoples R China.;[Lin, Zefeng; Ren, Zhi-an; Zhou, Menghu; Ruan, Binbin] Chinese Acad Sci, Inst Phys, Beijing Natl Lab Condensed Matter Phys, Beijing 100190, Peoples R China.
通讯机构：
[Ni, SL ] U;Univ South China, Sch Math & Phys, Hengyang 421001, Peoples R China.
摘要：
Here, pristine and Pd-intercalated 2 H − Ta S 2 single crystals with ( 00 l ) orientation were grown by the chemical vapor transport technique. The superconductivity (SC) and charge density wave (CDW) were characterized by magnetic and electrical transport measurements. We find that SC and CDW in the pristine 2 H − Ta S 2 condense respectively at transition temperatures T c ∼ 0.8 K and T CDW ∼ 78 K . The CDW order is completely suppressed, and T c is greatly enhanced to 4.5 K in 2 H − P d 0.04 Ta S 2 , which concludes a competing relation between the two collective electronic states. The positive Hall coefficient R H for both samples above 78 K indicates that hole-type carriers dominate the transport properties, and almost the same R H reveals tiny charge transfer between the intercalant Pd and the host Ta S 2 . The difference of R H below 78 K between Ta S 2 and Pd 0.04 Ta S 2 is attributed to the reconstruction of the Fermi surface by Pd-intercalation-induced collapse of the CDW order. Therefore, the prominently improved T c in 2 H − P d 0.04 Ta S 2 is mainly caused by the change of electronic structure due to the suppression of the CDW state rather than charge injection by Pd intercalation.
语种：
英文
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Intrinsic thermoelectric properties in biphenylene nanoribbons and effect of lattice defects
作者：
Xie, Zhong-Xiang;Chen, Xue-Kun;Yu, Xia;Deng, Yuan-Xiang;Zhang, Yong;...
期刊：
计算材料学(英文) ,2023年220:112041 ISSN：2057-3960
通讯作者：
Xie, Zhong-Xiang(xiezxhu@163.com)
作者机构：
[Xie, Zhong-Xiang; Jia, Pin-Zhen; Deng, Yuan-Xiang; Yu, Xia; Zhang, Yong] Hunan Inst Technol, Sch Sci, Hengyang 421002, Peoples R China.;[Chen, Xue-Kun] Univ South China, Sch Math & Phys, Hengyang 421001, Peoples R China.;[Zhou, Wu-Xing] Hunan Univ Sci & Technol, Sch Mat Sci & Engn, Xiangtan 411201, Peoples R China.
通讯机构：
[Zhong-Xiang Xie; Xia Yu; Pin-Zhen Jia] S;School of Science, Hunan Institute of Technology, Hengyang 421002,China
关键词：
Biphenylene nanoribbons;Lattice defects;Thermoelectric properties
摘要：
Intrinsic thermoelectric properties in biphenylene nanoribbons (BNRs) and effect of lattice defects are investigated by employing the nonequilibrium Green's function. A comparative analysis on intrinsic thermoelectric properties between graphene nanoribbons (GNRs) and BNRs is performed. Results show that although the Seebeck coefficient of BNRs is lower than that of the corresponding GNRs, BNRs exhibit better thermoelectric properties than the corresponding GNRs due to the lower phonon thermal conductance of BNRs. It is also shown that the lattice defects can enhance the maximum ZT (ZTmax) in armchair BNRs (ABNRs) and zigzag BNRs (ZGNRs), where the ZTmax can be up to 1.1 and 0.4 at T = 300 K, respectively. Moreover, such the enhancement in defective ZBNRs is more remarkable than that in defective ABNRs. Theoretical analysis reveals that this enhancement of the ZTmax originates from the substantial reduction of phonon thermal conductance due to the strong backscattering by the highly localized phonon states around the lattice defects. © 2023 Elsevier B.V.
语种：
英文
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Characterizing elastic constants of anisotropic materials by spherical indentation method
作者：
Liao, Yanguo;Xie, Shuibo
期刊：
Current Applied Physics ,2023年53:9-18 ISSN：1567-1739
通讯作者：
Xie, SB
作者机构：
[Xie, Shuibo; Liao, Yanguo] Univ South China, Sch Resource Environm & Safety Engn, Hengyang 421001, Peoples R China.;[Liao, Yanguo] Univ South China, Sch Math & Phys, Hengyang 421001, Peoples R China.;[Xie, Shuibo] Univ South China, Sch Civil Engn, Hengyang 421001, Peoples R China.
通讯机构：
[Xie, SB ] U;Univ South China, Sch Civil Engn, Hengyang 421001, Peoples R China.
关键词：
Elastic parameters /constants;Finite element (FE);Indentation modulus;Spherical indentation;Three dimensional (3D);Transversely isotropic materials
摘要：
By the theoretical analysis and the finite element (FE) method, a new model for measuring the elastic constants of transversely isotropic materials has been proposed from spherical indentation. A theoretical analysis of the spherical indentation modulus for the materials is presented. Extensive spherical indentation tests were implemented by three dimensional (3D) FE simulations. By fitting the simulation results, the analytical relationship correlating the elastic parameters with the indentation moduli at three different indentation orientation angles (0°, 45°, and 90°) was set up. The effectiveness of the proposed method was examined by a series of numerical indentation experiments. It is found that the calculated values by the proposed method are well consistent with the input elastic parameters. The sensitivity of the calculated elastic parameters to the experimental data was analyzed. Simultaneously, this method was applied to carbon fiber materials. The results calculated by the method proposed in this paper were compared with results obtained by the theoretical model and experimental measurement to verify the effectiveness of this method. Thus the proposed method is practiced and could be used to identify the elastic properties of transversely isotropic materials. © 2023
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英文
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AcsiNet: Attention-Based Deep Learning Network for CSI Prediction in FDD MIMO Systems
作者：
Jiang, Ya;Lin, Wenbin;Zhao, Weikun;Wang, Chaofeng
期刊：
IEEE WIRELESS COMMUNICATIONS LETTERS ,2023年12(3):471-475 ISSN：2162-2337
通讯作者：
Lin, WB
作者机构：
[Jiang, Ya; Lin, Wenbin; Wang, Chaofeng; Zhao, Weikun; Lin, WB] Univ South China, Sch Comp Sci, Hengyang 421001, Peoples R China.;[Lin, Wenbin; Lin, WB] Univ South China, Sch Math & Phys, Hengyang 421001, Peoples R China.
通讯机构：
[Lin, WB ] U;Univ South China, Sch Comp Sci, Hengyang 421001, Peoples R China.;Univ South China, Sch Math & Phys, Hengyang 421001, Peoples R China.
关键词：
Downlink;Uplink;Deep learning;Transmission line matrix methods;Three-dimensional displays;Feature extraction;Training;CSI prediction;deep learning;attention mechanism;FDD massive MIMO;planar antenna array
摘要：
In 5G frequency division duplex (FDD) systems, the user equipment needs to feedback the measured downlink channel state information (CSI) to the base station to improve the throughput. For massive multiple-input-multiple-output (MIMO) systems, each antenna in base station needs its CSI feedback, which results in significant transmission overhead and latency. We propose an attention-based deep learning network to directly predict the downlink CSI from the corresponding uplink one, eliminating the feedback overhead completely. Specifically, the uplink CSI is first compressed based on the 3D inverse discrete Fourier transform, then is fed into an attention-based deep learning network which can focus on key CSI characteristics. The simulation results show that the proposed method achieves high prediction accuracy and low complexity, indicating prospective applications in FDD massive MIMO systems.
语种：
英文
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The ability of BC3 to remove Cs from nuclear wastewater
作者：
Zhou, Nan;Qin, Yong;Zhang, Yang;Wu, Feihong;Yu, Wantang;...
期刊：
International Journal of Quantum Chemistry ,2023年123(8):e27072- ISSN：0020-7608
通讯作者：
Wu, Xijun(wuxijunusc@163.com)
作者机构：
[Wu, Feihong; Zhang, Yang; Zhou, Nan; Yu, Wantang] Univ South China, Sch Nucl Sci & Technol, Hengyang, Peoples R China.;[Wu, Xijun; Cheng, Jinjuan; Qin, Yong; Tan, Jie] Univ South China, Sch Math & Phys, Hengyang, Peoples R China.;[Wu, Xijun] Univ South China, Sch Math & Phys, Hengyang 421001, Peoples R China.
通讯机构：
[Xijun Wu] S;School of Mathematics and Physics, University of South China, Hengyang, China
关键词：
Cesium;Density functional theory;Electronic structure;Graphene;Radioisotopes;Adsorption characteristic;Adsorption energies;Adsorption rates;Cs;Density-functional-theory;Electronic.structure;First principles;Systematic analysis;Two-dimensional materials;Two-materials;Adsorption
摘要：
Density functional theory (DFT) was used to conduct a systematic analysis of the adsorption characteristics of Cs on three two-dimensional materials: graphene, C3N, and BC3. The adsorption energies of Cs were calculated, and the electronic structure of the system was analyzed. The dependence of adsorption energies on temperatures was taken into account, and the first-principles-derived adsorption energies were used to calculate the influence of temperature on the adsorption rate. It was discovered that BC3 is more stable than the other two materials, has good adsorption characteristics, and has performance that is not significantly degraded at high temperatures. The adsorption performances of other radionuclides I and Ag (which also have radionuclides) on BC3, were also calculated to compare with that of Cs. The results show that the adsorption capacity of Cs on BC3 is much greater than that of the two lighter elements. Based on this study, BC3 is a good candidate for removing Cs from nuclear wastewater. © 2022 Wiley Periodicals LLC.
语种：
英文
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Hopf Bifurcation Analysis of a Delayed Fractional BAM Neural Network Model with Incommensurate Orders
作者：
Li, Bingbing;Liao, Maoxin;Xu, Changjin;Li, Weinan
期刊：
Neural Processing Letters ,2023年55(5):5905-5921 ISSN：1370-4621
通讯作者：
Liao, Maoxin(maoxinliao@163.com)
作者机构：
[Li, Weinan; Li, Bingbing; Liao, Maoxin] Univ South China, Sch Math & Phys, Hengyang 421001, Hunan, Peoples R China.;[Xu, Changjin] Guizhou Univ Finance & Econ, Guizhou Key Lab Econ Syst Simulat, Guiyang 550004, Guizhou, Peoples R China.
通讯机构：
[Maoxin Liao] S;School of Mathematics and Physics, University of South China, Hengyang, People’s Republic of China
关键词：
Neural networks;BAM neural network;Critical delays;Critical value;Equilibrium point;Fractional order;Fractional-order BAM neural network;Hopf bifurcation analysis;Incommensurate ordering;Multi-delays;Neural network model;Hopf bifurcation
摘要：
In this paper, a six-neuron incommensurate fractional order BAM neural network model with multi-delays is considered. We demonstrate that the equilibrium point of the system loses its stability and Hopf bifurcation emerges when the delay passes through a critical value. And the relationship between the critical delay of Hopf bifurcation and size of fractional orders is found. Finally, some numerical simulations are given to verify the validity of the theoretical results. © 2022, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.
语种：
英文
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On the equivalence between a new family of APN quadrinomials and the power APN functions
作者：
Shi, Chenmiao;Peng, Jie;Zheng, Lijing;Lu, Shihao
期刊：
Cryptography and Communications ,2023年15(2):351-363 ISSN：1936-2447
通讯作者：
Peng, Jie(jpeng@shnu.edu.cn)
作者机构：
[Peng, Jie; Shi, Chenmiao; Lu, Shihao] Shanghai Normal Univ, Math & Sci Coll, Shanghai 200234, Peoples R China.;[Zheng, Lijing] Univ South China, Sch Math & Phys, Hengyang 421001, Hunan, Peoples R China.
通讯机构：
[Jie Peng] M;Mathematics and Science College of Shanghai Normal University, Shanghai, China
关键词：
APN function;Gold function;EA-equivalence;CCZ-equivalence
摘要：
Finding new (up to CCZ-equivalence) constructions of APN functions is one of the important but difficult topics in the study of cryptographic functions. Up to now, only 6 infinite families of power APN functions and 14 infinite families of APN polynomials are known. Although the CCZ-equivalence between power APN functions has been completely characterized, a similar theoretical analysis between polynomial APN functions and power APN functions is still missing. In this paper we prove that, in dimension not multiple of 3, a recently introduced family of APN quadrinomials is CCZ-inequivalent to any power APN function. Moreover, we prove that a more general family of APN functions is EA-equivalent to this family. © 2022, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.
语种：
英文
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Cryptographic functions with interesting properties from CCZ-equivalence
作者：
Li, Yanjun;Kan, Haibin;Peng, Jie;Zheng, Lijing
期刊：
Cryptography and Communications ,2023年15(4):831-844 ISSN：1936-2447
通讯作者：
Peng, J
作者机构：
[Li, Yanjun] Anhui Univ Finance & Econ, Inst Stat & Appl Math, Bengbu 233030, Anhui, Peoples R China.;[Kan, Haibin] Fudan Univ, Sch Comp Sci, Shanghai Key Lab Intelligent Informat Proc, Shanghai 200433, Peoples R China.;[Kan, Haibin] Shanghai Engn Res Ctr Blockchain, Shanghai 200433, Peoples R China.;[Kan, Haibin] Fudan Univ, Yiwu Res Inst, Yiwu City 322000, Peoples R China.;[Peng, Jie] Shanghai Normal Univ, Math & Sci Coll, Shanghai 200234, Peoples R China.
通讯机构：
[Peng, J ] S;Shanghai Normal Univ, Math & Sci Coll, Shanghai 200234, Peoples R China.
关键词：
Bent functions;Plateaued functions;Bent component;CCZ-equivalence
摘要：
In the last decades, because of their significantly important applications, a large number of papers were devoted to constructing cryptographic functions with interesting properties by various methods. In this paper, our motivation is to construct more families of such functions up to EA-equivalence (extended affine equivalence) by using the properties of CCZ-equivalence (Carlet-Charpin-Zinoviev equivalence). To this end, we present two CCZ-equivalent forms, and show their applications on bent functions, vectorial functions having the maximum number of bent components, and vectorial plateaued functions with single amplitude, respectively. © 2023, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.
语种：
英文
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Hydrogen-promoted in-void diffusion of helium in a 3C-SiC(310) twin boundary: a first-principles study
作者：
Zhang, Yang;Tang, Xian;Cheng, Guodong;Tan, Jie;Wu, Feihong;...
期刊：
Molecular Physics ,2023年121(13) ISSN：0026-8976
通讯作者：
Tang, X;Cheng, GD
作者机构：
[Wu, Feihong; Zhang, Yang; Tang, Xian; Xie, Xiangmin; Zhou, Nan] Univ South China, Sch Nucl Sci & Technol, Hengyang, Peoples R China.;[Cheng, Guodong] Univ South China, Coll Comp Sci, Hengyang, Peoples R China.;[Tan, Jie] Univ South China, Sch Math & Phys, Hengyang, Peoples R China.;[Tang, Xian] Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.;[Cheng, Guodong] Univ South China, Coll Comp Sci, Hengyang 421001, Peoples R China.
通讯机构：
[Tang, X ; Cheng, GD ] U;Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.;Univ South China, Coll Comp Sci, Hengyang 421001, Peoples R China.
关键词：
Density functional theory;Diffusion;Grain boundaries;Helium;Hydrogen;Silicon;Density-functional-theory;Effect of H;First-principle study;Formation energies;Grain-boundaries;Grain-boundary diffusion;He atoms;He bubbles;SiC grains;Twin boundaries;Silicon carbide
摘要：
The role of H atoms in the formation of irradiation-induced He bubbles in SiC grain boundaries (GBs) is unclear. The effects of H on the formation energies (Ef s) and diffusion behaviour of He in the 3C-SiC twin boundary (TB) were studied using the density functional theory. We observed that a He atom stabilises at three typical sites in the 3C-SiC (310) TB with Ef s = 1.95, 2.05, and 1.67 eV, which are significantly lower than those in the SiC grains. The addition of the H atom shifts the stable sites of He in the TB and increases Ef s to 4.66, 3.96, and 5.13 eV. The minimum energy pathways for He diffusion in TB were changed by the addition of H atom. Moreover, the H atom reduces the barrier from 3.69 to 1.04 eV for the He diffusion in one TB void and increases it from 1.30 to 4.08 eV for the He diffusion between adjacent TB voids. We interpreted the above results through the Bader charge, density of states, and atomic force analysis. The results indicate that H promotes the in-void diffusion but suppresses the inter-void diffusion of He atoms in SiC GBs, which favours the aggregation and nucleation of He in SiC GBs. © 2023 Informa UK Limited, trading as Taylor & Francis Group.
语种：
英文
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Numerical simulation of thermal damage in atherosclerotic plaque using microwave
作者：
Liu, Yong;Hu, Ji-wen;Xie, Ya-qian
期刊：
Proceedings of SPIE - The International Society for Optical Engineering ,2023年12603:6 ISSN：0277-786X
通讯作者：
Hu, JW
作者机构：
[Liu, Yong] Univ South China, Coll Elect Engn, Hengyang 421001, Peoples R China.;[Hu, Ji-wen; Xie, Ya-qian; Liu, Yong] Univ South China, Coll Math & Phys, Hengyang 421001, Peoples R China.
通讯机构：
[Hu, JW ] U;Univ South China, Coll Math & Phys, Hengyang 421001, Peoples R China.
会议名称：
Conference on Biophysical-Society-of-GuangDong-Province-Academic-Forum - Precise Photons and Life Health (PPLH)
会议时间：
DEC 09-11, 2022
会议地点：
Guangzhou, PEOPLES R CHINA
会议主办单位：
[Liu, Yong] Univ South China, Coll Elect Engn, Hengyang 421001, Peoples R China.^[Liu, Yong;Hu, Ji-wen;Xie, Ya-qian] Univ South China, Coll Math & Phys, Hengyang 421001, Peoples R China.
会议论文集名称：
Proceedings of SPIE
关键词：
Atherosclerosis;Electromagnetic wave;Ablation of heat;Finite element method
摘要：
The purpose of this study is to explore the thermal damage of microwave to atherosclerotic plaques in order to achieve the purpose of treating atherosclerosis. In this paper, a fluid-solid-heat coupling model of thermal ablation of atherosclerotic plaque is established (The coupling model of blood-plaque-electromagnetic wave is studied in this paper, in which the thermal ablation of atherosclerotic plaque means that the electromagnetic wave is used to generate heat, and the temperature of atherosclerotic plaque tissue rises. If the cells in it reach the threshold of death temperature, they will be killed, so as to achieve the purpose of thermal ablation.). The electromagnetic field and bio-thermal equation are solved and analyzed by finite element method. By calculating the temperature and thermal damage distribution of microwave on atherosclerotic plaque, the effect of microwave on thermal ablation of atherosclerotic plaque was evaluated. The results show that the thermal damage degree of atherosclerotic plaque is positively correlated with electromagnetic wave frequency, electromagnetic wave power and heating time. The model shows that electromagnetic wave hyperthermia may provide a new therapeutic mode for thermal ablation of atherosclerotic plaques. © 2023 SPIE.
语种：
英文
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Further investigation on bifurcation and their control of fractional-order bidirectional associative memory neural networks involving four neurons and multiple delays
作者：
Xu, Changjin;Zhang, Wei;Aouiti, Chaouki;Liu, Zixin;Liao, Maoxin;...
期刊：
Mathematical Methods in the Applied Sciences ,2023年46(3):3091-3114 ISSN：0170-4214
通讯作者：
Zhang, Wei(wzha19680317@126.com)
作者机构：
[Xu, Changjin] Guizhou Univ Finance & Econ, Guizhou Key Lab Econ Syst Simulat, Guiyang, Peoples R China.;[Zhang, Wei] Guangzhou Univ, Coll Econ & Stat, Guangzhou 510006, Peoples R China.;[Aouiti, Chaouki] Univ Carthage, Res Units Math & Applicat, Fac Sci Bizerta, UR13ES47, Bizerte, Tunisia.;[Liu, Zixin] Guizhou Univ Finance & Econ, Sch Math & Stat, Guiyang, Peoples R China.;[Liao, Maoxin] Univ South China, Sch Math & Phys, Hengyang, Peoples R China.
通讯机构：
[Wei Zhang] C;College of Economics and Statistics, Guangzhou University, Guangzhou, China
关键词：
Associative processing;Associative storage;Delay control systems;Dynamical systems;Memory architecture;Neural networks;Neurons;Stability;Time delay;Bi-directional associative memory neural networks;Bifurcation diagram;Differential dynamical systems;Fractional order;Fractional-order bidirectional associative memory neural network;Multiple delays;Neural-networks;Stability theories;Sufficient criterion;Variable transformation;Hopf bifurcation
摘要：
This work principally probes into the stability, the existence, and control of Hopf bifurcation of new established fractional-order delayed bidirectional associative memory (BAM) neural networks with four neurons. Firstly, based on the earlier study, we set up a class of new fractional-order multiple delayed BAM neural networks with four neurons. Secondly, applying an appropriate variable transformation, we get a new equivalent fractional-order single delayed BAM neural networks with four neurons. With the aid of the stability theory and bifurcation knowledge of fractional-order differential dynamical systems, a novel sufficient criterion to guarantee the stability and the appearance of Hopf bifurcation of the addressed fractional-order delayed BAM neural networks is set up. Thirdly, designing a suitable time-delayed feedback controller, the stability region and the time of appearance of Hopf bifurcation for the involved neural networks have been adjusted. Finally, two simulation examples are presented to illustrate the rationality of the mathematical derivation results. The study vindicates that the time delay has great effect on the stability, bifurcation, and its control for involved network models. The obtained fruits of this work can be effectively applied to control and design neural networks. Also, some research ideas will play a key role in studying the related fractional-order dynamical models in actual world. © 2021 John Wiley & Sons, Ltd.
语种：
英文
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Bubble dynamics and cavitation damage to curved elastic boundaries
作者：
Liu, Can;Hu, Jiwen;Xie, Yaqian;Liu, Yong;Lei, Weirui
期刊：
Journal of Physics: Conference Series ,2023年2535(1):012002 ISSN：1742-6588
通讯作者：
Hu, Jiwen(hu_sanping@163.com)
作者机构：
[Liu, Can; Liu, Yong] School of Electrical Engineering, University of South China, Hengyang;421001, China;[Hu, Jiwen; Xie, Yaqian; Lei, Weirui] School of Mathematics and Physics, University of South China, Hengyang;[Liu, Can; Hu, Jiwen; Xie, Yaqian; Liu, Yong; Lei, Weirui] 421001, China
摘要：
<jats:title>Abstract</jats:title>
<jats:p>Prediction of cavitation damage to the solid boundary is crucial in the application of ultrasound. The goal of this study is to investigate the potential for a cavitation bubble to cause mechanical effects on the curved elastic boundary and contribute to the understanding of the mechanisms of bubble-structure interaction. Effects of the surface curvature of the boundary are studied using the finite volume method. In the oscillatory migration of bubbles to the bottom of the boundary, there are several shape modes at the same time. The wall stress/deformation produced by impinging jets increases with parameter α. The bubble dynamic behaviors and the wall deformation have no significant effect as Young’s modulus equals or exceeds 60 MPa. Boundary deformation generated by tensile and compressive stresses during bubble collapse may be the basic mechanism of cavitation erosion. Due to the lack of visual observation and research on the acoustic cavitation effect, the key mechanism of ultrasonic cavitation is missing. Therefore, the importance of bubble dynamics and cavitation damage in this paper is self-evident</jats:p>
语种：
英文
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More classes of permutation hexanomials and pentanomials over finite fields with even characteristic
作者：
Zhang, Tongliang;Zheng, Lijing;Hao, Xinghui
期刊：
Finite Fields and Their Applications ,2023年91:102250 ISSN：1071-5797
通讯作者：
Zheng, LJ
作者机构：
[Hao, Xinghui; Zhang, Tongliang] North China Univ Sci & Technol, Coll Sci, Tangshan 063000, Hebei, Peoples R China.;[Zheng, Lijing] Univ South China, Sch Math & Phys, Hengyang 421001, Hunan, Peoples R China.
通讯机构：
[Zheng, LJ ] U;Univ South China, Sch Math & Phys, Hengyang 421001, Hunan, Peoples R China.
关键词：
Finite field;Permutation hexanomial and pentanomial
摘要：
In this paper, we further push the studies on permutation polynomials over the finite fields Fq2 with q=2m. We find the coefficients of f(x)=x+a1xs1(q−1)+1+a2xs2(q−1)+1+a3xs3(q−1)+1+a4xs4(q−1)+1+a5xs5(q−1)+1 over Fq2 that lead f(x) to be a permutation for [Formula presented] in case of a5=0, and find more new (si) such that f(x) is a permutation hexanomial of Fq2 with coefficients in F4. Some well-known results are covered by our results. The numerical results suggest that the sufficient conditions we find in the first class of permutation pentanomials are also necessary. © 2023 Elsevier Inc.
语种：
英文
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STRAIN-INDUCED MEDIUM-TEMPERATURE THERMOELECTRIC PERFORMANCE OF CU4TISE4: THE ROLE OF FOUR-PHONON SCATTERING
作者：
Chen, Xue-Kun;Zhang, En -Ming;Wu, Dan;Chen, Ke-Qiu
期刊：
PHYSICAL REVIEW APPLIED ,2023年19(4) ISSN：2331-7019
作者机构：
[Chen, Xue-Kun; Zhang, En -Ming] Univ South China, Sch Math & Phys, Hengyang 421001, Peoples R China.;[Wu, Dan] Changsha Univ Sci & Technol, Sch Phys & Elect Sci, Changsha 410114, Peoples R China.;[Chen, Ke-Qiu] Hunan Univ, Sch Phys & Elect, Dept Appl Phys, Changsha 410082, Peoples R China.
摘要：
Motivated by the synthesized Cu4TiSe4 with ultralow room-temperature thermal conductivity [Angew. Chem., Int. Ed. 60, 9106 (2021)], we systematically investigate its thermoelectric (TE) properties via combining Boltzmann transport equations and first-principles calculations. The results show that the thermal conductivity of Cu4TiSe4 determined considering only three-phonon scattering is reduced by about 40% after including four-phonon scattering at room temperature, indicating the importance of four-phonon scattering in phonon transport. On the other hand, the coexistence of high dispersion and valley degeneracy at the top valence band in the electronic structure causes a high power factor. Consequently, the isotropic figure of merit (ZT) value of 1.5 at 500 K is captured in the p-type doped Cu4TiSe4. In addition, the value of ZT can be further enhanced to 2.2 by applying 2.25% triaxial tensile strain, which is ascribed to the remarkably enhanced four-phonon scattering processes induced by the tensile strain. Meanwhile, the significant suppression of thermal conductivity allows the optimal carrier concentration for the ZT peak to be reduced, which is of important practical significance for the experimental preparation of Cu4TiSe4-based TE devices. Our results pave a way for the design of adjustable medium-temperature TE devices. © 2023 American Physical Society.
语种：
英文
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Influence of a Mo interlayer on the oxidation behavior of a Cr coating on a Zr alloy substrate
作者：
Ma, Jiaojiao;Tan, Jie;Zhou, Yue;Meng, Chuiyi;Wang, Hui;...
期刊：
Corrosion Science ,2023年218:111192 ISSN：0010-938X
通讯作者：
He, XJ;Tan, J
作者机构：
[Yang, Weiqi; He, Xiujie; Zhou, Yue; Meng, Chuiyi; Ma, Jiaojiao] Sun Yat sen Univ, Sino French Inst Nucl Engn & Technol, Zhuhai 519082, Guangdong, Peoples R China.;[Tan, Jie] Univ South China, Sch Math & Phys, Hengyang 421001, Hunan, Peoples R China.;[Wang, Hui] Chengdu Univ, Inst Adv Study, Interdisciplinary Mat Res Ctr, Chengdu 610106, Sichuan, Peoples R China.
通讯机构：
[He, XJ ] S;[Tan, J ] U;Sun Yat sen Univ, Sino French Inst Nucl Engn & Technol, Zhuhai 519082, Guangdong, Peoples R China.;Univ South China, Sch Math & Phys, Hengyang 421001, Hunan, Peoples R China.
关键词：
Mo interlayer;Coating;Accident tolerant fuel;Oxidation;Zirconium alloys
摘要：
Cr-based coatings with or without a Mo interlayer were deposited on a Zr substrate by multi-arc ion plating, and the effect of the Mo interlayer on the oxidation behavior of the coatings at different time lengths (maximum 90 min) at 1160 °C was investigated. Atomic scale characterization confirms that, on the one hand, the Mo interlayer prevents the Cr coating from reacting with the Zr substrate to form the ZrCr2 Laves phase and, on the other hand, the solid solution structure generated due to Mo doping effectively guarantees the integrity of the Cr2O3 oxide layer and the residual Cr coating. © 2023 Elsevier Ltd
语种：
英文
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A novel monotone finite volume element scheme for diffusion equations
作者：
Nie, Cunyun;Shu, Shi;Liu, Menghuan
期刊：
Journal of Computational and Applied Mathematics ,2022年414:114458 ISSN：0377-0427
通讯作者：
Nie, Cunyun(ncy1028@163.com)
作者机构：
[Nie, Cunyun] Hunan Inst Engn, Sch Computat Sci & Elect, Xiangtan 411104, Hunan, Peoples R China.;[Shu, Shi] Xiangtan Univ, Sch Math & Comp Sci, Xiangtan 411105, Hunan, Peoples R China.;[Liu, Menghuan] Univ South China, Sch Math & Phys, Hengyang 421001, Hunan, Peoples R China.
通讯机构：
[Cunyun Nie] S;School of Computational Science and Electronics, Hunan Institute of Engineering, Xiangtan 411104, Hunan, China
关键词：
Diffusion;Nonlinear equations;Partial differential equations;Tensors;Barycenters;Control volumes;Diffusion equations;Diffusion problems;Finite volume element;Linear finite volume element;Monotonicity;Nonlinear two-point flux;Triangular elements;Two-point;Finite volume method
摘要：
We present a novel monotone finite volume element scheme for the diffusion problem on triangular grids. Firstly, one fictitious triangular element is introduced for each edge of any element, and another vertex of this fictitious element is on the outward extended straight line passing through two points: The vertex opposite to this edge and the barycenter of the element. The diffusive tensor and the solution in this element are continuously extended to its corresponding fictitious element. The fictitious element and the continuous extension not only avoid the phenomenon that the control volume segment passes through other elements, but also are helpful to the construction and theoretical analysis for our monotone scheme. Secondly, one new nonlinear two-point flux formulation is obtained for some part control volume edge whose another endpoint is the barycenter of the fictitious element, and this straight segment crosses through the common edge of the triangular element and its fictitious one. The approximation of κ∇u on this straight control volume edge is constructed by some weighted average with the gradients of two finite element functions, and the weighted coefficients are determined by the nonlinear two-point flux idea. Furthermore, we proved that the new scheme is monotone under some conditions: the diffusion tensor and exact solution functions are properly smooth, and the partition step size h is properly small, and the solutions on three nodes of any element are not nonnegative, and furthermore not simultaneously zero, and the nodes of the fictitious element are properly chosen. We also proved that the corresponding coefficient matrix is of M-matrix. Finally, we carry on some typical experiments. Numerical results verify the monotonicity of this new scheme, and confirm its accuracy and stability. © 2022 Elsevier B.V.
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英文
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Density functional theory investigation of Cs, Co and Ag separation by functionalised graphene membrane
作者：
Zhou, Nan;Qin, Yong;Liu, Wenguan;Wu, Xijun;Cheng, Jinjuan
期刊：
Molecular Physics ,2022年120(23):Article: e2137067 ISSN：0026-8976
通讯作者：
Wu, Xijun(wuxijunusc@163.com);Cheng, Jinjuan(chengjinjuan@usc.edu.cn)
作者机构：
[Zhou, Nan] Univ South China, Sch Nucl Sci & Technol, Hengyang, Peoples R China.;[Wu, Xijun; Cheng, Jinjuan; Qin, Yong] Univ South China, Sch Math & Phys, Hengyang 421001, Peoples R China.;[Liu, Wenguan] Sun Yat Sen Univ, Sino French Inst Nucl Engn & Technol, Zhuhai, Peoples R China.
通讯机构：
[Xijun Wu; Jinjuan Cheng] S;School of Mathematics and Physics, University of South China, Hengyang, People’s Republic of China<&wdkj&>School of Mathematics and Physics, University of South China, Hengyang, People’s Republic of China
关键词：
Nuclide;adsorption;membrane separation;porous graphene oxide;density functional theory
摘要：
This work simulates radionuclides enrichment and separation from radioactive wastewater through functionalised porous graphene oxide (PGO) with a six-membered ring hole structure and hydroxyl (-OH) functional groups, using density functional theory (DFT). Cs, Ag, and Co in particular are selected for theoretical simulations in order to better understand the separation mechanism from the radioactive wastewater. The results demonstrate that, except for Co, the adsorption energy of nuclides on PGO membranes is higher than on perfect graphene membranes, and that the adsorption of Ag shifts from physisorption to chemisorption. Cs has a higher energy barrier than Co or Ag. It cannot permeate the PGO membrane and only concentrates on the surface. The separation of Cs from other nuclides using a PGO membranes is attributed mainly to the strong electronic coupling between hydroxyl functional groups and Cs. It is found, in addition, that the adsorption performance of the PGO membranes for Co and Ag decreases with increasing temperature, but has relatively stable adsorption for Cs. These research results demonstrate that a PGO membrane containing six-membered ring holes can effectively screen Cs from radioactive wastewater. © 2022 Informa UK Limited, trading as Taylor & Francis Group.
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英文
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Resonant power absorption in nonuniform toroidal helicon plasma sources
作者：
Du, Dan;Qiao, Guan Jin;Pan, Guang Zu;Yang, Kai Jian;Xiang, Dong;...
期刊：
Fusion Engineering and Design ,2022年176:113046 ISSN：0920-3796
通讯作者：
Gong, XY
作者机构：
[Du, Dan] Univ South China, Dept Math & Phys, Hengyang 421001, Peoples R China.;[Yang, Kai Jian; Qiao, Guan Jin] Univ South China, Dept Elect Engn, Hengyang 421001, Peoples R China.;[Pan, Guang Zu; Gong, Xue Yu; Xiang, Dong] Univ South China, Dept Nucl Sci & Technol, Hengyang 421001, Peoples R China.;[Gong, XY] Univ South China, Hengyang, Peoples R China.
通讯机构：
[Gong, XY ] U;Univ South China, Hengyang, Peoples R China.
关键词：
Double-saddle antenna;Helicon plasma;Standing wave;Resonant power absorption
摘要：
In this paper, we present numerical simulation results that indicate that under certain conditions, a double-saddle antenna can excite helicon modes that resonate with the driving frequency in a nonuniform toroidal plasma, and m=1 and m=2 resonant standing helicon waves can separate or coexist in the toroidal plasma. The power absorption associated with the resonant standing wave is much larger than the power absorption associated with the nonresonant eigenmodes and accounts for most of the RF power deposited into the plasma. By adjusting the antenna frequency and wavenumber kz, the wave field structure, such as the standing wave pattern, the partially travelling-partially standing wave structure and the standing wave structure with amplitude modulation, can be controlled, which means that one can possibly control the resonant power absorption through careful antenna geometry and frequency design. © 2022
语种：
英文
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Constructing New APN Functions Through Relative Trace Functions
作者：
Zheng, Lijing;Kan, Haibin;Li, Yanjun;Peng, Jie;Tang, Deng
期刊：
IEEE Transactions on Information Theory ,2022年68(11):7528-7537 ISSN：0018-9448
通讯作者：
Kan, Haibin(hbkan@fudan.edu.cn)
作者机构：
[Zheng, Lijing] Univ South China, Sch Math & Phys, Hengyang 421001, Hunan, Peoples R China.;[Kan, Haibin] Fudan Univ, Shanghai Key Lab Intelligent Informat Proc, Sch Comp Sci, Shanghai 200433, Peoples R China.;[Kan, Haibin] Fudan Univ, Shanghai Engn Ctr Blockchains, Shanghai 200433, Peoples R China.;[Li, Yanjun] Anhui Univ Finance & Econ, Inst Stat & Appl Math, Bengbu 233030, Anhui, Peoples R China.;[Peng, Jie; Li, Yanjun] Shanghai Normal Univ, Math & Sci Coll, Shanghai 200234, Peoples R China.
通讯机构：
[Kan, H.] F;Fudan University, China
关键词：
APN functions;CCZ-equivalence;quadratic functions;relative trace functions
摘要：
Let n=2m. In 2020, Budaghyan, Helleseth and Kaleyski [IEEE TIT 66(11): 7081-7087, 2020] considered a family of quadrinomials over F2n of the form (equation presented). They showed that two infinite classes of almost perfect nonlinear (APN) functions belong to this family when gcd (6,m)=1. We observe that these two infinite classes of APN quadrinomials and the infinite class of APN polynomials from the Budaghyan-Carlet family belong to a more general family of polynomials over F2n with the form f(x)=a Trnm(F(x))+a2m Trnm(G(x)), where a F2n F2m, and both F and G are quadratic functions over F2n. We characterize when f(x) is APN. With the help of our characterization, letting F(x)=bx2i+1 and G(x)=cx2s+1 with b, F2n, we obtain an infinite family of APN functions of the form f(x) when cd(2,m)=1 and verify that for n=10 two APN instances from this infinite family are CCZ-inequivalent to each other, and to any APN function over F210 from the previously known infinite families. © 1963-2012 IEEE.
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英文
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Interlayer coupling-induced controllable negative differential thermal resistance in graphene/h-BN van der Waals heterostructure
作者：
Chen, Xue-Kun;Tan, Jia-Ling;Pang, Min;Xie, Zhong-Xiang;Zhou, Wu-Xing;...
期刊：
Applied Physics Letters ,2022年121(14):142203 ISSN：0003-6951
通讯作者：
Xie, Zhong-Xiang(xiezxhu@163.com);Zhou, Wu-Xing(wuxingzhou@hnu.edu.cn);Liu, Jun(lj332125065@163.com)
作者机构：
[Pang, Min; Chen, Xue-Kun; Liu, Jun; Tan, Jia-Ling] Univ South China, Sch Math & Phys, Hengyang 421001, Peoples R China.;[Xie, Zhong-Xiang] Hunan Inst Technol, Dept Math & Phys, Hengyang 421002, Peoples R China.;[Zhou, Wu-Xing] Hunan Univ Sci & Technol, Sch Mat Sci & Engn, Xiangtan 411201, Peoples R China.;[Zhou, Wu-Xing] Hunan Univ Sci & Technol, Hunan Prov Key Lab Adv Mat New Energy Storage & Co, Xiangtan 411201, Peoples R China.
通讯机构：
[Zhong-Xiang Xie] D;[Wu-Xing Zhou; Jun Liu] S;School of Materials Science and Engineering & Hunan Provincial Key Laboratory of Advanced Materials for New Energy Storage and Conversion, Hunan University of Science and Technology , Xiangtan 411201, China<&wdkj&>School of Mathematics and Physics, University of South China , Hengyang 421001, China<&wdkj&>Department of Mathematics and Physics, Hunan Institute of Technology , Hengyang 421002, China
摘要：
The van der Waals (vdW) heterostructures employing graphene and hexagonal boron nitride (h-BN) have emerged as a typical system for building emergent two-dimensional devices, such as atomically thin transistors or capacitors. Herein, we study the nonlinear thermal transport in such vdW heterostructure by non-equilibrium molecular dynamics simulations. The results show that an obvious negative differential thermal resistance (NDTR) phenomenon can be observed under small temperature bias when the interlayer coupling becomes stronger. The vibrational spectra analysis manifests that the phonon filtering mechanism induced by interlayer coupling greatly hinders the interfacial thermal transport. To obtain the optimum conditions, the dependence of NDTR on the system length, lateral width, external temperature, and defect density is taken into account. Our findings extend the phonon filtering mechanism to thermal information processing. © 2022 Author(s).
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英文
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