摘要：
Many multi-objective optimization problems in reality are dynamic, requiring the optimization algorithm to quickly track the moving optima after the environment changes. Therefore, response strategies are often used in dynamic multi-objective algorithms to find Pareto optimal. In this paper, we propose a hybrid prediction strategy based on the classification of decision variables, which consists of three steps. After detecting the environment change, the first step is to analyze the influence of each decision variable on individual convergence and distribution in the new environment. The second step is to adopt different prediction methods for different decision variables. Finally, adaptive selection is applied to the solution set generated in the first and second steps, and solutions with good convergence and diversity are selected to make the initial population more adaptable to the new environment. The prediction strategy can help the solution set converge while maintaining its diversity. The experimental results and performance show that the proposed algorithm is capable of significantly improving the dynamic optimization performance compared with five state-of-the-art evolutionary algorithms.
期刊：
BULLETIN DES SCIENCES MATHEMATIQUES,2021年173:103054 ISSN：0007-4497
通讯作者：
Saminathan Ponnusamy
作者机构：
[Liu, Gang] Hengyang Normal Univ, Hunan Prov Key Lab Intelligent Informat Proc & Ap, Coll Math & Stat, Hengyang 421002, Hunan, Peoples R China.;[Liu, Zhihong] Guilin Univ Technol, Coll Sci, Guilin 541004, Guangxi, Peoples R China.;[Ponnusamy, Saminathan] Indian Inst Technol Madras, Dept Math, Chennai 600036, Tamil Nadu, India.
通讯机构：
[Saminathan Ponnusamy] D;Department of Mathematics, Indian Institute of Technology Madras, Chennai-600 036, India
关键词：
Bohr inequality;Bohr radius;Bohr-Rogosinski inequality;Bounded analytic function;Symmetric function
摘要：
In this article, by combining appropriate refined Bohr's inequalities with some techniques concerning bounded analytic functions defined in the unit disk, we generalize and improve several Bohr-type inequalities for such functions. (C) 2021 Elsevier Masson SAS. All rights reserved.
摘要：
Several works on optical higher-order differential operations have recently attracted attention, particularly in image processing for edge detection. However, the inefficient differential operation leads to barriers to practical applications. Here, we report an anisotropic epsilon-near-zero slab to significantly enhance the transmission efficiency of second-order differentiators and discuss the Berry phase mechanism of this optical calculation process. Through a rigorous full-wave analysis of the process, we find that the conversion efficiency of differential operation depends on the spin-orbit interactions. Our scheme can strengthen the spin-orbit interaction by introducing anisotropy, which significantly enhances the transmission efficiency. We finally give transfer functions to reveal how to improve the efficiency and compare the quadratic coefficient among different systems. This highly efficient differentiation operation may develop significant applications in fast, compatible, and power-efficient ultrathin devices for data processing and biological imaging.
摘要：
Optical spin-Hall effect (SHE) exhibits many intriguing features as a linearly polarized (LP) light beam strikes an interface at incident angles around the Brewster angle, but the underlying physics remains obscure. Here, we elucidate the physics through reanalyzing this problem employing rigorous calculations and the Berry phase concept. As a circularly polarized (CP) light beam strikes an optical interface, the reflected light beam contains two components, a spin-flipped abnormal mode acquiring geometric phases (thus exhibiting a spin-Hall shift) and a spin-maintained normal mode without such phases. Strengths of these two modes are determined by the incident angle and the optical properties of the interface. Under the LP incidence, however, a spin component inside the reflected light beam must be the sum of normal and abnormal components of reflected light beams corresponding to CP incidences with different helicity, which thus sensitively depends on the incident angle. In particular, at incident angles near the Brewster one, reflection coefficients for two CP components exhibit opposite signs, leading to significant destructive interferences between normal and abnormal modes, finally generating highly deformed reflected light patterns with anomalously enhanced spin-Hall shifts. These findings can be extended to both reflected and transmitted cases with Brewster-like behaviors. Our analyses reinterpret previously discovered effects, providing an alternative understanding on the SHE of light.
作者：
Xie, Y. X.;Yan, Y. J.;Li, X.;Ding, T. S.;Ma, C.
期刊：
Journal of Instrumentation,2021年16(7):T07006 ISSN：1748-0221
作者机构：
[Ma, C.; Yan, Y. J.; Xie, Y. X.; Li, X.; Ding, T. S.] Univ South China, Coll Nucl Sci & Technol, Hengyang 421001, Hunan, Peoples R China.;[Xie, Y. X.] Hengyang Normal Univ, Coll Phys & Elect Engn, Hengyang 421008, Hunan, Peoples R China.
关键词：
Analysis and statistical methods;Models and simulations;Radiation monitoring;Gamma detectors (scintillators, CZT, HPGe, HgI etc.)
摘要：
This article gives a scintillation detector fault diagnosis method based on BP neural network. From the aspect of output signals of scintillation detectors, the wavelet packet transform is used to extract the energy characteristic vectors which are treated as the input of BP neural network, and a training database is established as well as BP neural network parameters are optimized. Then the method is employed to establish a fault recognition model and fault types can be concluded. Finally, the simulation data are compared with those of two other methods (the statistical diagnosis method and an method based on multi-classification support vector machine). The experimental results illustrate that the application of proposed method can improve the fault diagnosis accuracy of scintillation detectors effectively.
摘要：
Protection of entanglement from disturbance of the environment is an essential task in quantum information processing. We study the dynamic behaviours of quantum entanglement between two uncoupled qubits, which are immersed in a common phase decoherence environment. We examine the validity of the local non-Hermitian operation in the amplification of qubit–qubit entanglement. In particular, using analytical and numerical investigations, we show explicitly that the quantum entanglement of the two qubits can be greatly amplified by means of non-Hermitian operation.
作者机构：
[Xu, Qiang; Yu, Fu-Xing; Chen, Ping; Wang, Run; Zhang, Yue; He, Xiao-Li; Ma, Xing-Juan; Xiong, Zu-Hong; Jia, Ya-Lan; Zhang, Yong; Gao, Chun-Hong] Southwest Univ, Sch Phys Sci & Technol, MOE Key Lab Luminescence & Real Time Anal, Chongqing 400715, Peoples R China.;[Deng, Yan-Hong; Gao, Chun-Hong] Hengyang Normal Univ, Coll Phys & Elect Engn, Hunan Prov Appl Basic Res Base Optoelect Informat, Hengyang 421002, Peoples R China.
通讯机构：
[Chun-Hong Gao] S;School of Physical Science and Technology, MOE Key Laboratory on Luminescence and Real Time Analysis, Southwest University, Chongqing, 400715, China<&wdkj&>Hunan Provincial Applied Basic Research Base of Optoelectronic Information Technology, College of Physics and Electronics Engineering, Hengyang Normal University, Hengyang, 421002, China
摘要：
Tetraphenylphosphonium chloride (TPPCl) is used as an additive in the antisolvent for preparing the quasi-two Dimensional (quasi-2D) perovskite film. This strategy is not only beneficial for the morphology formation but also the phase tuning of the quasi-2D perovskite film. Highly efficient and stable perovskite light-emitting diodes (PeLEDs) were achieved with the maximum luminance of 35,000 cd/m2, the maximum current efficiency of 48.0 cd/A and the maximum external quantum efficiency (EQE) of 12.42%. Due to the reduced exciton quenching rate, improved charge carrier injection and transport ability, the electroluminescent performance of the TPPCl-based PeLEDs has been enhanced.
通讯机构：
[Xiaolin Wei] D;Department of Physics & Hunan Institute of Advanced Sensing and Information Technology, Xiangtan University, Xiangtan, Hunan 411105 China<&wdkj&>College of Physics and Electronic Engineering, Hengyang Normal Univerisity, Hengyang 421002, China
关键词：
First-principle calculation;NRR;Single atom catalysts
摘要：
Single atom electrocatalysts show great potential to nitrogen reduction reaction (NRR). Here, we studied transition metals (V, Cr, Nb, Mo, Ta, W) doped on MoSe2 as single atom electrocatalysts by first-principles theory. We investigated different NRR pathways and its corresponding Gibbs free energy. It is found that W/MoSe2 has a better NRR catalytic activity than others due to the larger charge composition with N2 molecule. Furthermore, the limiting potential has a quasi-linear relationship with the N2 adsorption energy, which is also related to the changes of charge composition. The result highlights a new family of efficient TM/MoSe2 catalysts for NRR.
期刊：
Journal of Instrumentation,2021年16(12):T12011 ISSN：1748-0221
作者机构：
[Fan, Z.; Mo, Y.; Lin, F.; Hu, T.; Yuan, H.; Tan, Y.] College of Physics and Electronic Engineering, Hengyang Normal University, Hengyang, Hunan Province 421008, China;[Xie, L.] College of mathematics and statistics, Hengyang Normal University, Hengyang, Hunan Province 421008, China
摘要：
The collection efficiency of the hemispherical internal cell of radon monitors depends on many factors, with the distribution of the electric field and the relative humidity of the air being particularly important. COMSOL is used to simulate an internal cell with a plastic upper surface. Simulation results show a relatively uniform gradient of the electric field. Assuming that the electric field felt by the positively charged Po-218 ions in the internal cell is a linear function of its radial coordinate, a mathematical model of the collection efficiency is proposed. From this model, we obtained the following: 1) under the same neutralization rate and potential, the electric field gradient has little effect on the collection efficiency; 2) under the same neutralization rate, the collection efficiency increases with the potential on the cell wall. If the neutralization rate is small, then the potential value for the maximum collection efficiency is also small. At a relative humidity of 6%–10%, the collection efficiency saturates for values of the electric potential on the cell wall larger than 5 kV; 3) under the same potential, a large neutralization rate corresponds to reduced collection efficiency. At high potential, the collection efficiency is relatively less affected by the neutralization rate. Higher collection efficiency can be achieved under high potential and low humidity conditions. This study provides a theoretical foundation to design the internal cell of radon monitor for improving the collection efficiency of Po-218.
作者机构：
[Wang, Haibin; He, Xiongying; Shi, Yimin; Zhou, Zheng] Hunan Inst Technol, Dept Phys, Hengyang 421002, Peoples R China.;[Tang, Shiqing] Hengyang Normal Univ, Coll Phys & Elect Engn, Hengyang 421002, Peoples R China.;[Deng, Haiming] Xiangnan Univ, Sch Elect Informat & Elect Engn, Chenzhou 423000, Peoples R China.;[Zhong, Honghua] Cent South Univ Forestry & Technol, Inst Math & Phys, Changsha 410004, Peoples R China.
通讯机构：
[Honghua Zhong] I;Institute of Mathematics and Physics, Central South University of Forestry and Technology, Changsha 410004, China
关键词：
Bose-Einstein condensates;Quantum droplets;Three-body recombination loss
摘要：
We investigate the dynamics of dissipative quantum droplets (QDs) forming in one-dimensional binary Bose gases subjected to three-body recombination loss and linear gain in perturbed optical lattices. We demonstrate by a perturbation procedure that an alimentation of atoms from an external feeding source to the QDs may lead to the formation of dynamically-stabilized dissipation-controlled QDs. It is worth noting that such dissipation-controlled QDs are independent of the initial condensation norm and are solely determined by the gain and loss parameters. We further study the dynamics of the dissipation controlled QDs with varying norm due to the gain and loss mechanisms in relatively weak optical lattices. It is found that the stationary dissipative QDs can be accelerated and either continuously travel across the potential barriers or eventually perform trapped oscillations in different lattice sites by selecting the appropriate gain and loss parameters. Finally, we deal with the collision between the dissipative QDs. It is revealed that two slowly moving dissipative QDs with varying norm may merge or collide quasi-elastically depending on their initial separation, which is quite different from QDs in the conservative systems. Specially, we explore the collision dynamics of the dissipative QDs in a single lattice site provided that the spatial period of optical lattices is large enough. The in-phase interaction between the dissipative QDs tends to merge, while the out-of-phase interaction displays quasi-elastic collision. (c) 2021 Elsevier Ltd. All rights reserved.
通讯机构：
[Jinhua Zheng; Juan Zou] K;[Shouyong Jiang; Shengxiang Yang] S;Key Laboratory of Intelligent Computing and Information Processing (Ministry of Education), Xiangtan University, Xiangtan, Hunan 411105, China<&wdkj&>Hunan Provincial Key Laboratory of Intelligent Information Processing and Application, Hengyang Normal University, Hengyang 421002, China<&wdkj&>Key Laboratory of Intelligent Computing and Information Processing (Ministry of Education), Xiangtan University, Xiangtan, Hunan 411105, China<&wdkj&>School of Computer Science and Informatics, De Montfort University, Leicester LE1 9BH, UK<&wdkj&>School of Computer Science, University of Lincoln, Lincoln LN6 7TS, UK
关键词：
Changing preference point;Dynamic multi-objective evolutionary algorithms (DMOEAs);Reference points;The region of interest (ROI)
摘要：
Most of the existing dynamic multi-objective evolutionary algorithms (DMOEAs) are effective, which focuses on searching for the approximation of Pareto-optimal front (POF) with well-distributed in handling dynamic multi-objective optimization problems (DMOPs). Nevertheless, in real-world scenarios, the decision maker (DM) may be only interested in a portion of the corresponding POF (i.e., the region of interest) for different instances, rather than the whole POF. Consequently, a novel DMOEA based decomposition and preference (DACP) is proposed, which incorporates the preference of DM into the dynamic search process and tracks a subset of Pareto-optimal set (POS) approximation with respect to the region of interest (ROI). Due to the presence of dynamics, the ROI, which is defined in which DM gives both the preference point and the neighborhood size, may be changing with time-varying DMOPs. Consequently, our algorithm moves the well-distributed reference points, which are located in the neighborhood range, to around the preference point to lead the evolution of the whole population. When a change occurs, a novel strategy is performed for responding to the current change. Particularly, the population will be reinitialized according to a promising direction obtained by letting a few solutions evolve independently for a short time. Comprehensive experiments show that this approach is very competitive compared with state-of-the-art methods. (c) 2021 Elsevier Inc. All rights reserved.
摘要：
Dynamically controlling terahertz (THz) wavefronts in a designable fashion is highly desired in practice. However, available methods working at microwave frequencies do not work well in the THz regime due to lacking suitable tunable elements with submicrometer sizes. Here, instead of locally controlling individual meta-atoms in a THz metasurface, we show that rotating different layers (each exhibiting a particular phase profile) in a cascaded metadevice at different speeds can dynamically change the effective Jones-matrix property of the whole device, thus enabling extraordinary manipulations on the wavefront and polarization characteristics of a THz beam impinging on the device. After illustrating our strategy based on model calculations, we experimentally demonstrate two proof-of-concept metadevices, each consisting of two carefully designed all-silicon transmissive metasurfaces exhibiting different phase profiles. Rotating two metasurfaces inside the fabricated devices at different speeds, we experimentally demonstrate that the first metadevice can efficiently redirect a normally incident THz beam to scan over a wide solid-angle range, while the second one can dynamically manipulate both the wavefront and polarization of a THz beam. Our results pave the way to achieving dynamic control of THz beams, which is useful in many applications, such as THz radar, and bio- and chemical sensing and imaging.
摘要：
How to explore the physical effect and characterize physical parameters in atomic scale crystals is still a challenging issue in modern optics. We detect the photonic spin Hall effect in monolayer MoS2 to study the atomic light-matter interaction. Due to the sensitive dependence of the spin-Hall shifts on the optical constants of MoS2, we propose this fundamental effect as a metrological tool for the parameter characterization. Combined with the weak-value technique, the experimental results show that the complex refractive index can be extracted by treating the atomically thin MoS2 as a homogeneous slab with an effective thickness. However, modeling the thin crystal as a surface current can determine the optical conductivity with a high measurement resolution. We believe this fast and precise measurement of optical parameters can provide a reliable approach to investigate optical properties for transition metal dichalcogenides.
通讯机构：
[Luo, X.-J.] S;[Tang, S.-L.] N;Nanjing National Laboratory of Microstructures, China;Shanghai Key Laboratory of Materials Protection and Advanced Materials in Electric PowerChina
关键词：
transport properties;molecular electronic devices;nonequilibrium Green's functions
摘要：
We study the entanglement dynamics of two atoms coupled to their own Jaynes–Cummings cavities in single-excitation space. Here, we use concurrence to measure atomic entanglement, and consider the Bell-like states to be initial states. Our analysis suggests that collapse and revival take place in entanglement dynamics. The physical mechanism behind entanglement dynamics is periodic information and energy exchange between atoms and light fields. For the initial Bell-like states,evolutionary periodicity of the atomic entanglement can only be found if the ratio of the two atom–cavity coupling strengths is a rational number. Also, whether there is a time translation between two kinds of initial Bell-like state depends on odd versus even numbers of the coupling-strength ratio.
通讯机构：
[Xiaohui Deng; Jiayu Dai] C;College of Physics and Electronic Engineering, Hengyang Normal University, Hengyang, Hunan, 421002, China<&wdkj&>Department of Physics, National University of Defense Technology, Changsha, Hunan, 410073, China<&wdkj&>College of Physics and Electronic Engineering, Hengyang Normal University, Hengyang, Hunan, 421002, China<&wdkj&>Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui, 230026, China
关键词：
Magnetic semiconductor;Curie temperature;Hole doping
摘要：
It is urgently needed to explore new high temperature magnetic semiconductor or improve its Curie temperature through various physical or chemical methods. Here, we report a new two-dimensional (2D) CrOCl monolayer that has a relatively high Curie temperature. More importantly, it can be further enhanced to over room temperature through hole doping. The structure and the modulation method to improve spin order temperature in this paper thus may be applied in spintronics.
