摘要：
We investigate the hydrostatic equilibrium configurations of strange stars within the framework of Rastall-Rainbow theory of gravity. These stars are primarily composed of strange quark matter, with its distribution governed by the color-flavor-locked phase of quark matter equation of state (EoS). Using this EoS, we numerically solve the modified Tolman-Oppenheimer-Volkoff equation to obtain different quark star models. We find that the parameters from this modified gravity have specific contributions to the structure of quark stars and introduce new descriptions for massive celestial bodies. Also, the mass-radius relation strongly depends on the parameters from the considered EoS. Furthermore, we analyze the impact of these parameters on the gravitational redshift and compactness of quark stars.
摘要：
We study wave equations with various spins on the background of a general spherically symmetric spacetime. We obtain the unified expression of the Teukolsky-like master equations and the corresponding radial equations with the general spins. We also discuss the gauge dependence in the gravitational-wave equations, which have appeared in previous studies.
期刊：
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS,2024年2024(02):046 ISSN：1475-7516
作者机构：
[Nakajima, Hiroaki] School of Mathematics and Physics, University of South China, Hengyang, 421001, China;School of Physical Science and Technology, Southwest Jiaotong University, Chengdu, 610031, China;[Guo, Ya; Lin, Wenbin] School of Mathematics and Physics, University of South China, Hengyang, 421001, China<&wdkj&>School of Physical Science and Technology, Southwest Jiaotong University, Chengdu, 610031, China
摘要：
<jats:title>Abstract</jats:title>
<jats:p>We study an axisymmetric metric satisfying the Petrov type D property with some additional
ansatze, but without assuming the vacuum condition. We find that our metric in turn becomes
conformal to the Kerr metric deformed by one function of the radial coordinate. We then study the
gravitational-wave equations on this background metric in the case that the conformal factor is
unity. We find that under an appropriate gauge condition, the homogeneous wave equations admit the
separation of the variables, which is also helpful for solving the nonhomogeneous equations. The
resultant ordinary differential equation for the radial coordinate gives a natural extension of
the Teukolskyequation.</jats:p>
期刊：
Qualitative Theory of Dynamical Systems,2024年23(5):1-22 ISSN：1575-5460
通讯作者：
Zhou, M
作者机构：
[Zhou, Mi; Zhou, M] Univ South China, Sch Math & Phys, Hengyang 421001, Hunan, Peoples R China.;[Zhang, Lu] Xiangtan Univ, Fac Math & Computat Sci, Xiangtan 411105, Hunan, Peoples R China.
通讯机构：
[Zhou, M ] U;Univ South China, Sch Math & Phys, Hengyang 421001, Hunan, Peoples R China.
关键词：
Fractional Langevin equation;Existence;Uniqueness;Fixed point theorem;Stability
摘要：
In this work, we deal with a more general form of fractional Langevin equation. The equation's nonlinearity term f is relevant to fractional integral and fractional derivative. By using the fixed point theorems, we study the existence and uniqueness of solutions of initial value problem for the nonlinear fractional Langevin equation and obtain some new results. Further, by using the technique of nonlinear functional analysis, we study the stability of Ulam-Hyers, Ulam-Hyers-Rassias and semi-Ulam-Hyers-Rassias for the initial value problem of nonlinear Langevin equation. Finally, some examples are given to show the effectiveness of theoretical results.
通讯机构：
[Xu, BM ; Wang, XZ] S;[Wang, XZ ] U;Southern Univ Sci & Technol, Dept Mat Sci & Engn, Shenzhen 518055, Peoples R China.;Univ South China, Sch Elect Engn, Hengyang 421001, Peoples R China.;Southern Univ Sci & Technol, Shenzhen Engn Res & Dev Ctr Flexible Solar Cells, Shenzhen 518055, Peoples R China.
摘要：
As the most promising lead-free perovskite, tin-based perovskite has attracted much attention due to its suitable bandgap and low toxicity. However, many defects (tin vacancy defects caused by Sn2+ oxidation to Sn4+, grain boundary defects and point defects) in tin-based perovskite lead to serious losses in device efficiency. Here, a universal and effective doping strategy is delivered to improve the structure and optoelectronic properties of tin-based perovskite films through 2,8-dibromo-dibenzothiophene-S,S-dioxide (BrDS) doping. The introduction of BrDS can effectively inhibit the oxidation of Sn2+ and passivate grain boundary defects and point defects in the perovskite films. The tin-based perovskite film doped with BrDS exhibits higher carrier lifetime and crystal quality. As a result, the BrDS-doped device achieves a power conversion efficiency of 14.98% with a certified efficiency of 14.36%, which is one of the highest PCEs among all values reported to date for tin-based PSCs. In addition, the BrDS-doped PSC devices exhibit significantly improved long-term stability and improved operational stability in a N-2 atmosphere. This work represents a noteworthy step towards manufacturing efficient and stable tin-based PSCs.
摘要：
Abstract: A generalized scheme of chaos synchronization, which is called multiple function projective synchronization, is first reported in this paper. This synchronization scheme is more generalized than many existing ones. Under the scheme, the synchronous behavior between two synchronized systems is more complicated. By utilizing the proposed synchronization scheme and introducing the parameter perturbation factor, a novel algorithm of secure communication is designed. From theoretical analysis and numerical simulations, the validity and feasibility of this algorithm is proved. Finally, some discussions and comparison experiments are established to illuminate the security of this algorithm.#@#@#摘要: 本文提出了一种新的混沌同步方案——多重函数投影同步，该同步方案比许多现有同步方案更加广义，两个同步系统之间的同步行为更加复杂。基于所提的同步方案并引入参数扰动因子，设计了一种新的保密通信算法，并通过理论分析和数值模拟，证实了算法的有效性和可行性。最后，通过讨论和对比实验展示了该算法的安全性。
期刊：
Fuzzy Sets and Systems,2024年479:108856 ISSN：0165-0114
通讯作者：
Liu, HL
作者机构：
[Xiao, Qizhen; Liu, Hongliang; Liu, HL; Luo, Zhiyong] Univ South China, Sch Math & Phys, Hengyang 421001, Peoples R China.;[Xiao, Qizhen; Liu, Hongliang; Liu, HL] Univ South China, Hunan Key Lab Math Modeling & Sci Comp, Hengyang 421001, Peoples R China.
通讯机构：
[Liu, HL ] U;Univ South China, Sch Math & Phys, Hengyang 421001, Peoples R China.;Univ South China, Hunan Key Lab Math Modeling & Sci Comp, Hengyang 421001, Peoples R China.
关键词：
Aperiodic DoS attacks;Resilient synchronization;Fixed-time stability;Fuzzy neural networks;Reaction-diffusion terms
摘要：
This work focuses on the resilient fixed -time synchronization of delayed fuzzy memristive reaction -diffusion neural networks under denial -of -service (DoS) attacks. To efficaciously tolerate the aperiodic DoS attacks, a new appropriate controller is designed to ensure the fixed -time resilient synchronization of the systems. Moreover, two mild sufficient conditions are first proposed and the constrained techniques of attacking intervals are employed to overcome the challenge of estimating the upper bound of the settling time under aperiodic DoS attacks. Lastly, an example is utilized to illustrate the effectiveness and feasibility of the theoretical result.
摘要：
Recently, CdX (X = Se, Te) materials have garnered notable interest owing to their great application potential for high-efficiency solar cells, fiber optic communication systems, and nanoelectronic devices. The performance of optoelectric devices is significantly influenced by the thermal conductivity. In this study, a combination of machine-learning methods and first-principles calculations is utilized to investigate the phonon thermal transport properties of CdSe and CdTe, as well as to give deep insights into the phonon behavior in heat transfer. It is found that acoustic phonons dominate the lattice thermal conductivity (lc) in CdSe, while optical phonons contribute around 50 % to the lc value in CdTe. There are strikingly strong four-phonon scattering phenomena in both materials, which result in 55 % and 66 % reduction in lc values for CdSe and CdTe, respectively. Further analysis shows that the mid-frequency phonons play an important role in amplifying the four-phonon scattering. Its special frequency positions permit an unusually large number of four-phonon scattering processes to occur and cause large scattering of low-frequency phonons. This mechanism differs from earlier proposed features regarding large acoustic-optical gaps, bunching of acoustic branches and four-phonon Fermi resonance, which implies strong four-phonon anharmonicity. Thus, the present work opens up new prospects in the exploration and design of innovative thermoelectric material, which provides a more thorough understanding of the fourphonon scattering mechanisms in crystalline solids.
摘要：
Let q = 2(m). In this paper, we investigate permutation pentanomials over F-q(2) of the form f(x) = x(t) + x(1)(r)(q-1)+t + x(2)(r)(q-1)+t + x(3)(r)(q-1)+t + x(4)(r)(q-1)+t with gcd(x(4)(r) + x(3)(r) + x(2)(r) + x(1)(r) + 1, xt + x(1)(t-r) + x(2)(t-r)+ x(</span>)(t-r) + x(4)(t-r) ) = 1. We transform the problem concerning permutation property of f(x) into demonstrating that the corresponding fractional polynomial permutes the unit circle U of F-q(2) with order q + 1 via a well-known lemma, and then into showing that there are no certain solution in F-q for some highdegree equations over F-q associated with the fractional polynomial. According to numerical data, we have found all such permutations with 4 <= t < 100, 1 <= r(i )< t, i is an element of [1, 4]. Several permutation polynomials are also investigated from the fractional polynomials permuting the unit circle U found in this paper. (c) 2024 Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar
摘要：
In this paper, we give six classes of permutation polynomials of the form (x(pm) - x + delta)(s) + a(x) over F-2(2m) and six classes of permutation polynomials of the form (x(pm) - x + delta)(s) + ax(pm) + a(pm) x over F-p(2m) (p being an odd prime), respectively. In addition, we also investigate permutation polynomials obtained from piecewise functions. Consequently, we find some complete permutation polynomials.
摘要：
In this paper, we construct three classes of permutation quadrinomials with Niho exponents of the form
$$f(x)=\alpha _0x^r+\alpha _1x^{s_1(p^m-1)+r}+\alpha _2x^{s_2(p^m-1)+r}+\alpha _3x^{s_3(p^m-1)+r}\in \mathbb {F}_{p^{n}}[x]$$
, where p is an odd prime,
$$n=2m $$
is a positive even integer, and
$$(r,s_1,s_2,s_3)=(1,\frac{-1}{p^k-2},1,\frac{p^k-1}{p^k-2})$$
,
$$(1,\frac{p^k+1}{p^k+2},1,\frac{1}{p^k+2})$$
and (3, 1, 2, 3), respectively. The exponents of the first two classes are considered for the first time, and the third class covers all the permutation polynomials proposed by Gupta (Designs Codes and Cryptography 88, 1–17, 2020).
摘要：
The outstanding physical properties of hexagonal boron nitride (h-BN) make it highly valuable for use in nanoelectromechanical systems. We investigate the nonlinear stochastic vibration of h-BN nanowire affected by piezoelectric. The nonlinear beam model considering the impact of piezoelectric effect excited by random force is established. Molecular dynamic simulations were utilized to determine the potential energy of h-BN nanowires under varying amplitudes affected by an external electric field. The findings suggest that an increase in the intensity of the electric field can result in buckling behavior, leading to the appearance of two stable points. The cases of pre-buckling and post-buckling of nonlinear dynamic behavior of h-BN nanowire induced by piezoelectric effect is discussed in this paper. Furthermore, the impact of the intensity of random force on the nonlinear stochastic vibration characteristics of h-BN nanowire is also examined.
摘要：
<jats:title>Abstract</jats:title>
<jats:p>In the present work, taking the α particle preformation probabilities Pα from Xu et al. [Xu and Ren, Nucl. Phys. A 760,303, 2005], which were extracted by fitting the experimental half-lives of α decay, based on a phenomenological harmonic oscillator potential model (HOPM) [Bayrak, J Phys G 47:025102, 2020], refitting 178 α decay half-lives of even-even nuclei taken from the latest nuclear property table NUBASE2020, we obtain the only one adjustable parameter V0 = 162.6MeV in HOPM i.e. the depth of nuclear potential, while the corresponding root-mean-square&#xD;(rms) deviation is σ = 0.322. Furthermore, for considering the contribution of centrifugal potential to unfavored α decay half-lives, adding a new term d(l(l+ 1))^0.5 (d and l are the adjustable parameter and orbital angular momentum taken away by emitted α particle) to the logarithmic form of favored α decay half-lives under the HOPM framework, we propose an improved simple model (ISM) for calculating favored and unfavored α decay half-lives. Fitting the experimental half-lives of 205 unfavored α decay, we obtain d = 0.381. Using&#xD;the improved simple model, the unfavored α decay half-lives of 128 odd-A and 77 odd-odd nuclei are calculated, the results are improved by 54.2% and 53.6%, respectively, compared with HOPM. In addition, we extend ISM to predict the α decay half-lives of 144 nuclei with Z = 117,118,119 and 120. For comparison, the improved model with eight parameters (DUR) proposed by Deng et al. [Deng, Phys. Rev. C 101: 034307, 2020] and the modified universal decay law (MUDL) put forward by Soylu et al. [Soylu, Nucl. Phys. A 1013: 122221, 2021] are also used. The predictions of these models and/or formulas are basically consistent with each other.</jats:p>
摘要：
Theoretical investigations are conducted to examine the impact of toroidal rotation and ion collisional viscosity on low-frequency zonal flow (LFZF) in a tokamak plasma with the fluid model. The results indicate that while the frequency of LFZF remains unchanged during an isothermal process with
$$\gamma { = }1$$
, its damping rate is influenced by both toroidal rotation and ion collisional viscosity. Specifically, as the ion collisional viscosity increases, so does the damping rate of LFZF; conversely, as the toroidal rotation As its Mach number rises, its damping rate decreases. For a non-isothermal process with
$$\gamma \, > 1$$
(such as
$$\gamma = 5/3$$
), the damping rate and frequency of LFZF are influenced by both toroidal rotation and ion collisional viscosity. It has been demonstrated that when the toroidal rotation Mach number surpasses a certain threshold, the frequency transitions from zero to a finite value, while the damping rate decreases as the toroidal rotation Mach number increases for LFZF. Furthermore, it has been observed that the damping rate of LFZF increases while the frequency decreases with an increase in ion collisional viscosity. Moreover, when the ion collisional viscosity surpasses a certain threshold, the frequency of LFZF drops to zero.
摘要：
We present an atomistic simulation of thermoelectric properties in cove-edged graphene nanoribbons (CGNRs) via the nonequilibrium Green's function. Different from gapless zigzag graphene nanoribbons (ZGNRs), CGNRs exhibit a noticeable bandgap. Such a bandgap can be modulated by varying three structural parameters (namely, the width N, the distance between adjacent coves m, as well as the shortest offset n) of CGNRs, which can give rise to the transition from semiconducting to semi-metallic. Due to the less dispersive phonon bands and the decrease in the number of phonon channels of CGNRs, they are found to have the lower phonon thermal conductance than ZGNRs. Modulation of CGNRs can produce over tenfold improvement of the maximum of ZT compared to ZGNRs. This improvement is due to the promotion of the Seebeck coefficient together with the degradation of the phonon thermal conductance of CGNRs compared to ZGNRs.
期刊：
Finite Fields and Their Applications,2024年94:102354 ISSN：1071-5797
通讯作者：
Kan, HB
作者机构：
[Zheng, Lijing] Univ South China, Sch Math & Phys, Hengyang 421001, Hunan, 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.;[Zhang, Tongliang] North China Univ Sci & Technol, Coll Sci, Tangshan 063000, Hebei, Peoples R China.
通讯机构：
[Kan, HB ] F;Fudan Univ, Sch Comp Sci, Shanghai Key Lab Intelligent Informat Proc, Shanghai 200433, Peoples R China.;Shanghai Engn Res Ctr Blockchain, Shanghai 200433, Peoples R China.;Fudan Univ, Yiwu Res Inst, Yiwu City 322000, Peoples R China.
关键词：
Finite field;Permutation trinomial
摘要：
Let q = 2m and Fq3 be the finite field with q3 elements. In this paper, based on the multivariate method, resultant elimination, and transforming into dealing with some equations over finite fields, we propose two classes of permutation trinomials of Fq3. We illustrate that these two classes of permutation trinomials are QM-inequivalent to all known permutation polynomials over Fq3. Some well-known results can be covered by our theorems.(c) 2023 Elsevier Inc. All rights reserved.
摘要：
The sign of the speed of bistable traveling wave solution is an important focus in the field of population dynamics, since it can be used to predict which species will win the competition and ultimately survive. In this paper, the sign of bistable wave speed of a plankton model with cubic nonlinearity is studied. By a delicate analysis, a sufficient condition for bistable wave to be stationary is first obtained. Symmetric and multiplication properties for stationary bistable wave are established. By upper-lower solution method and comparison principle, two sufficient conditions are found so that the bistable wave speed is negative or positive. Moreover, numerical simulations are performed to illustrate our theoretic conclusions.
摘要：
Functionalized two-dimensional materials have been widely explored as possible candidates to adsorb radioactive nuclide due to their large specific surface and tunable properties. In this work, single-sided fluorinated graphene (ssFG) with different fluorinated rates have been predicted to be an effective adsorbent for uranium atoms using density functional theory (DFT) simulations. The linear response method was used to obtain a more accurate Hubbard U value (3.1 eV) of the 5f orbital of the uranium atom. Our calculated results show that uranium atoms were energetically favorable adsorbed on the C2F, C6F, C8F ssFGs, and their adsorption energies are 3.45, 1.20, and 1.12 eV, respectively. The electronic analysis, such as the density of states, charge transfer and differential charge density suggest that the uranium atom has the strongest chemisorption with the substrate C2F. C2F also exhibits excellent performance in terms of the adsorption capacity of uranium atoms. In addition, the critical temperature for the adsorption-desorption transition of uranium atoms was predicted to be 632 K by the adsorption rate equation. The results suggest that ssFG, especially C2F, was a promising material for uranium adsorption, have promising application in nuclear waste disposal, extraction of uranium from seawater, uranium detection, etc.