期刊：
Fractal and Fractional,2023年7(2):142- ISSN：2504-3110
通讯作者：
Maoxin Liao
作者机构：
[Li, Weinan; Li, Bingbing; Liao, Maoxin; Chen, Huiwen] Univ South China, Sch Math & Phys, Hengyang 421001, Peoples R China.;[Xu, Changjin] Guizhou Univ Finance & Econ, Guizhou Key Lab Econ Syst Simulat, Guiyang 550004, Peoples R China.
通讯机构：
[Maoxin Liao] S;School of Mathematics and Physics, University of South China, Hengyang 421001, China<&wdkj&>Author to whom correspondence should be addressed.
摘要：
In this paper, we study the stability and Hopf bifurcation of a class of six-neuron fractional BAM neural networks with multiple delays. Firstly, the model is transformed into a fractional neural network model with two nonidentical delays by using variable substitution. Then, by assigning a value to one of the time delays and selecting the remaining time delays as parameters, the critical value of Hopf bifurcation for different time delays is calculated. The study shows that when the time lag exceeds its critical value, the equilibrium point of the system will lose its stability and generate Hopf bifurcation. Finally, the correctness of theoretical analysis is verified by simulation.
期刊：
Communications in Nonlinear Science and Numerical Simulation,2023年118:107043 ISSN：1007-5704
通讯作者：
Changjin Xu
作者机构：
[Xu, Changjin] Guizhou Univ Finance & Econ, Guizhou Key Lab Econ Syst Simulat, Guiyang 550004, Peoples R China.;[Mu, Dan; Liu, Zixin; Pang, Yicheng] Guizhou Univ Finance & Econ, Sch Math & Stat, Guiyang 550004, Peoples R China.;[Liao, Maoxin] Univ South China, Sch Math & Phys, Hengyang 421001, Peoples R China.;[Aouiti, Chaouki] Univ Carthage, Fac Sci Bizerta, UR13ES47 Res Units Math & Applicat, Bizerte 7021, Tunisia.
通讯机构：
[Changjin Xu] G;Guizhou Key Laboratory of Economics System Simulation, Guizhou University of Finance and Economics, Guiyang 550004, PR China
关键词：
Boundedness;Delay;Existence and uniqueness;Fractional-order 4D neural networks;Hopf bifurcation;Stability
摘要：
Delay has a vital influence on the dynamics of neural networks. Exploring the effect of time delay on the dynamics of neural networks has become a hot issue in mathematics and engineering fields. In this current manuscript, on the basis of the earlier publications, we put forward a new fractional-order 4D neural networks incorporating two different time delays. First of all, the existence and uniqueness, boundedness of the solution of the fractional-order 4D neural networks incorporating two different time delays. are analyzed by applying contraction mapping principle, construct of an adaptive function, respectively. Next, the stability and the emergence of Hopf bifurcation are explored by making use of the stability and bifurcation theory of fractional-order dynamical system. A series of novel stability criteria and bifurcation conditions guaranteeing the stability and the emergence of Hopf bifurcation of the considered fractional-order 4D neural networks under the different delay cases are built. What,s more, the impact of delay on stabilizing neural networks and controlling the emergence of Hopf bifurcation of neural networks is adequately uncovered. At last, Matlab simulation figures are presented to confirm scientificness of the derived prime conclusions. The derived prime conclusions of this manuscript are perfectly innovative and own momentous theoretical reference value in the control issue and design aspect of neural networks.(c) 2022 Published by Elsevier B.V.
期刊：
JOURNAL OF PHYSICS-CONDENSED MATTER,2023年35(7) ISSN：0953-8984
作者机构：
[Jia, Pin-Zhen; Xie, Zhong-Xiang; Deng, Yuan-Xiang; Yu, Xia; Xie, Jia-Ping; Zhang, Yong] Hunan Inst Technol, Dept Math & Phys, Hengyang 421002, Peoples R China.;[Chen, Xue-Kun] Univ South China, Sch Math & Phys, Hengyang 421001, Peoples R China.;[Zhou, Wu-Xing; Zeng, Yu-Jia] Hunan Univ Sci & Technol, Sch Mat Sci & Engn, Xiangtan 411201, Peoples R China.;[Zhou, Wu-Xing; Zeng, Yu-Jia] Hunan Univ Sci & Technol, Hunan Prov Key Lab Adv Mat New Energy Storage & Co, Xiangtan 411201, Peoples R China.
关键词：
in-plane heterostructures;thermal conductivity;thermoelectric transport;two-dimensional materials;van der Waals heterostructures
摘要：
The rapid development of synthesis and fabrication techniques has opened up a research upsurge in two-dimensional material heterostructures, which have received extensive attention due to their superior physical and chemical properties. Currently, thermoelectric energy conversion is an effective means to deal with the energy crisis and increasingly serious environmental pollution. Therefore, an in-depth understanding of thermoelectric transport properties in two-dimensional heterostructures is crucial for the development of micro-nano energy devices. In this review, the recent progress of two-dimensional heterostructures for thermoelectric applications is summarized in detail. Firstly, we systematically introduce diverse theoretical simulations and experimental measurements of the thermoelectric properties of two-dimensional heterostructures. Then, the thermoelectric applications and performance regulation of several common two-dimensional materials, as well as in-plane heterostructures and van der Waals heterostructures, are also discussed. Finally, the challenges of improving the thermoelectric performance of two-dimensional heterostructures materials are summarized, and related prospects are described.
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.
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.
作者机构：
[Zhu, De-Xing; Li, Xiao-Hua; Xu, Yang-Yang; Li, XH] Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.;[Chu, Li-Jia] Anhui Univ Sci & Technol, Dept Chem Engn, Huainan 232001, Peoples R China.;[Wu, Xi-Jun; Wu, XJ] Univ South China, Sch Math & Phys, Hengyang 421001, Peoples R China.;[He, Biao] Cent South Univ, Coll Phys & Elect, Changsha 410083, Peoples R China.;[Li, Xiao-Hua; Li, XH] Univ South China, Natl Exemplary Base Int Sci & Tech, Collaborat Nucl Energy & Nucl Safety, Hengyang 421001, Peoples R China.
通讯机构：
[Li, XH ; Wu, XJ ] U;Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.;Univ South China, Sch Math & Phys, Hengyang 421001, Peoples R China.;Univ South China, Natl Exemplary Base Int Sci & Tech, Collaborat Nucl Energy & Nucl Safety, Hengyang 421001, Peoples R China.;Univ South China, Cooperat Innovat Ctr Nucl Fuel Cycle Technol & Equ, Hengyang 421001, Peoples R China.
关键词：
2p radioactivity;CPPM;Half-lives;Excited state
摘要：
In the present work, we extend the Coulomb and Proximity Potential Model (CPPM) to study two-proton (2p) radioactivity from excited states while the proximity potential is chosen as AW95 proposed by Aage Withner in 1995. Demonstration reveals that the theoretical results acquired by CPPM exhibit a high level of consistency with prior theoretical models such as the unified fission model (UFM), generalized liquid-drop model (GLDM) and effective liquid-drop model (ELDM). Furthermore, within the CPPM, we predicted the half-lives of potential 2p radioactive nuclei for which experimental data are currently unavailable. The predicted results were then assessed, compared with UFM, ELDM and GLDM models, and examined in detail.
摘要：
In this paper, the stability and Hopf bifurcation of a six-neuron fractional BAM neural network model with multiple delays are considered. By transforming the multiple-delays model into a fractional-order neural network model with a delay through the variable substitution, we prove the conditions for the existence of Hopf bifurcation at the equilibrium point. Finally, our results are verified by numerical simulations.
作者机构：
[Zhang, Yu-Peng; Li, Xiao-Hua; Chen, Xun; Chen, X] Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.;[Watanabe, Akira] Univ South China, Sch Math & Phys, Hengyang 421001, Peoples R China.
通讯机构：
[Chen, X ] U;Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.
摘要：
The differential cross sections of elastic proton-proton (pp) and proton-antiproton (pp<overline> ) scattering are studied in a holographic QCD model, considering the strong and Coulomb interaction in the Regge regime. Based on previous studies of strong interactions described in terms of Pomeron and Reggeon exchange, we add the contribution of Coulomb interaction described by photon exchange. We present the momentum transfer dependence of the contribution rates for each component, especially for the Coulomb-nuclear interference, which refers to the cross term between both interactions. For the adjustable parameters for the strong interaction, we can adopt the values determined in previous studies, and there are no extra adjustable parameters that need to be determined for the Coulomb interaction. It is presented that the resulting differential cross sections are consistent with the data for pp and pp<overline> scattering.
作者机构：
[Pan, Chaohong; Hu, Shulin] Univ South China, Sch Math & Phys, Hengyang 421001, Peoples R China.;[Wang, Lin] Hunan Inst Traff Engn, Basic Dept, Hengyang 421001, Peoples R China.
通讯机构：
[Wang, L ] H;Hunan Inst Traff Engn, Basic Dept, Hengyang 421001, Peoples R China.
关键词：
asymptotic behavior;Lotka–Volterra model;three species;global stability;weighted functional space
摘要：
The stability of traveling waves for the Lotka-Volterra competition system with three species is investigated in this paper. Specifically, we first show the asymptotic behavior of traveling wave solutions and then establish the local stability and the global stability under the weighted functional space. For local stability, the spectrum approach is used, while for global stability, the comparison principle and squeezing theorem are combined.
期刊：
Journal of Radioanalytical and Nuclear Chemistry,2023年332(2):243-250 ISSN：0236-5731
通讯作者：
Zhenghua Xu<&wdkj&>Yong Liu
作者机构：
[Lin, Dongying; Chen, Yifan; Dai, Xingwang; Yan, Chengyan; Song, Juan; Li, Xiangyang] Univ South China, Sch Resource Environm & Safety Engn, Hengyang 421001, Hunan, Peoples R China.;[Xu, Zhenghua] Univ South China, Sch Math & Sci, Hengyang 421001, Hunan, Peoples R China.;[Liu, Yong; Li, Xiangyang] Hunan Prov Engn Technol Res Ctr Uranium Tailings T, Hengyang 421001, Hunan, Peoples R China.;[Liu, Yong; Li, Xiangyang] Hunan Prov Engn Res Ctr Radioact Control Technol U, Hengyang 421001, Hunan, Peoples R China.;[Liu, Yong] Shenzhen Univ, Coll Phys & Optoelect Engn, Shenzhen 518060, Guangdong, Peoples R China.
通讯机构：
[Zhenghua Xu] S;[Yong Liu] H;School of Mathematics and Science, University of South China, Hengyang, China<&wdkj&>Hunan Province Engineering Technology Research Centre of Uranium Tailings Treatment Technology, Hengyang, China<&wdkj&>Hunan Province Engineering Research Centre of Radioactive Control Technology in Uranium Mining and Metallurgy, Hengyang, China<&wdkj&>College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, China
摘要：
Soil cohesion can be improved with reinforcement treatment. Glass fiber, polypropylene fiber, jute, and other commonly used organic and inorganic fiber materials were used as experimental materials to investigate the effect of reinforcement fiber type and dosage on radon exhalation in uranium tailings overlying soil under high temperature environment, and soil samples with different fiber types and dosages were prepared for radon exhalation test. The correlation analysis method was used to investigate the relationship between the radon exhalation law and the type and amount of reinforcing fibers in the overburden, and a linear function was constructed between the radon exhalation rate and the type and amount of reinforcing fibers. The results show that the radon exhalation rate of the jute reinforcement treatment is the lowest under the same dosage, followed by the polypropylene reinforcement treatment, and the effect of the glass fiber reinforcement treatment is the worst, but the radon exhalation rate of all treatments is high. In plain soil, increasing the fiber reinforcement reduces the degree of soil cracking and the rate of radon exhalation. When the material source and cost are taken into account, the jute reinforcement treatment can achieve a lower radon exhalation rate.
期刊：
BRIEFINGS IN BIOINFORMATICS,2023年24(6) ISSN：1467-5463
通讯作者：
Chen, YP;Lin, WB
作者机构：
[Li, Zhe; Tu, Xinyi] Univ South China, Sch Comp, Hengyang, Peoples R China.;[Chen, Yuping; Chen, YP] Univ South China, Sch Pharm, 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 ; Chen, YP ] U;Univ South China, Sch Pharm, Hengyang 421001, Peoples R China.;Univ South China, Sch Math & Phys, Hengyang 421001, Peoples R China.
关键词：
drug–drug interaction;pre-taining;heterogeneous graph neural network;multi-source information
摘要：
The simultaneous use of two or more drugs due to multi-disease comorbidity continues to increase, which may cause adverse reactions between drugs that seriously threaten public health. Therefore, the prediction of drug-drug interaction (DDI) has become a hot topic not only in clinics but also in bioinformatics. In this study, we propose a novel pre-trained heterogeneous graph neural network (HGNN) model named HetDDI, which aggregates the structural information in drug molecule graphs and rich semantic information in biomedical knowledge graph to predict DDIs. In HetDDI, we first initialize the parameters of the model with different pre-training methods. Then we apply the pre-trained HGNN to learn the feature representation of drugs from multi-source heterogeneous information, which can more effectively utilize drugs' internal structure and abundant external biomedical knowledge, thus leading to better DDI prediction. We evaluate our model on three DDI prediction tasks (binary-class, multi-class and multi-label) with three datasets and further assess its performance on three scenarios (S1, S2 and S3). The results show that the accuracy of HetDDI can achieve 98.82% in the binary-class task, 98.13% in the multi-class task and 96.66% in the multi-label one on S1, which outperforms the state-of-the-art methods by at least 2%. On S2 and S3, our method also achieves exciting performance. Furthermore, the case studies confirm that our model performs well in predicting unknown DDIs. Source codes are available at https://github.com/LinsLab/HetDDI.
摘要：
The effective one-body method provides a framework to apply the black hole perturbation theory to the binary system where two masses can be comparable. We study the gravitational-wave equation in the background of the effective one-body system for the spinless binary, which is in general available with the spherically symmetric background as well. We obtain the gauge conditions for the decoupled wave equation, and also give the solutions to the gauge conditions in terms of the metric perturbation for a special case, which extends the result by Jing et al. (Sci. China-Phys. Mech. Astron. 65, 260411 (2022)). Finally we obtain the gravitational-wave equation which is the generalization of the Teukolsky equation.
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 & UKappa; backward difference 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.(C) 2022 Elsevier B.V. All rights reserved.
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.
摘要：
In the present study, we deal with the stability and the onset of Hopf bifurcation of two type delayed BAM neural networks (integer-order case and fractional-order case). By virtue of the characteristic equation of the integer-order delayed BAM neural networks and regarding time delay as critical parameter, a novel delay-independent condition ensuring the stability and the onset of Hopf bifurcation for the involved integer-order delayed BAM neural networks is built. Taking advantage of Laplace transform, stability theory and Hopf bifurcation knowledge of fractional-order differential equations, a novel delay-independent criterion to maintain the stability and the appearance of Hopf bifurcation for the addressed fractional-order BAM neural networks is established. The investigation indicates the important role of time delay in controlling the stability and Hopf bifurcation of the both type delayed BAM neural networks. By adjusting the value of time delay, we can effectively amplify the stability region and postpone the time of onset of Hopf bifurcation for the fractional-order BAM neural networks. Matlab simulation results are clearly presented to sustain the correctness of analytical results. The derived fruits of this study provide an important theoretical basis in regulating networks.
