作者机构：
[Tang, Shiqing] Hengyang Normal Univ, Coll Phys & Elect Engn, Hengyang 421002, Peoples R China.;[Li, Dongxiao; Yang, Chong] Shenyang Normal Univ, Coll Phys Sci & Technol, Shenyang 110034, Peoples R China.;[Shao, Xiaoqiang] Northeast Normal Univ, Ctr Quantum Sci & Sch Phys, Changchun 130024, Peoples R China.;[Shao, Xiaoqiang] Northeast Normal Univ, Ctr Adv Optoelect Funct Mat Res, Minist Educ, Changchun 130024, Peoples R China.;[Shao, Xiaoqiang] Northeast Normal Univ, Minist Educ, Key Lab UV Light Emitting Mat & Technol, Changchun 130024, Peoples R China.
通讯机构：
[Dongxiao Li; Xiaoqiang Shao] A;Authors to whom correspondence should be addressed.<&wdkj&>College of Physics Science and Technology, Shenyang Normal University, Shenyang 110034, China<&wdkj&>Authors to whom correspondence should be addressed.<&wdkj&>Center for Quantum Sciences and School of Physics, Northeast Normal University, Changchun 130024, China<&wdkj&>Center for Advanced Optoelectronic Functional Materials Research, and Key Laboratory for UV Light-Emitting Materials and Technology of Ministry of Education, Northeast Normal University, Changchun 130024, China
摘要：
We investigate the impact of Raman scattering on pure quartic solitons (PQSs) in an optical fiber with quartic dispersion. An analytical expression of the Raman-induced frequency shift (RWS) of a PQS is obtained by using the variational approach with the Gaussian function ansatz. We find the RIFS of a PQS is inversely proportional to the sixth power of pulse width, when the fiber is short enough. The RWS of a PQS is more sensitive to the pulse width, compared with that of a conventional soliton which is inversely proportional to the fourth power of pulse width. The theoretical predictions show good agreement with numerical results. In addition, we also discuss the RIFS of the other three typical pulses with the same peak power and pulse width as the PQS. These results provide a thorough understanding of the role of higher-order nonlinear effects on the propagation dynamics of PQSs. (C) 2022 Optica Publishing Group
摘要：
Achieving highly directive radiation with broadband operation, low scattering, and thin profile for a circularly polarized (CP) antenna is particularly challenging and yet rarely reported. Here, we propose a strategy of a CP Cassegrain meta-antenna by combining a planar helical antenna, a metasurface main reflector, and a metamaterial subreflector. The main reflector is designed to achieve focusing for CP waves at 13 GHz. The subreflector is chessboard-configured chiral metamaterial slab composed of two different types of chiral meta-atoms, aiming to achieve spin- and direction-selective CP transmissions and reflections. The distance between two reflectors is half of focal length, which enables our antenna to be dubbed as a folded reflectarray. The low radar cross section (RCS) is achieved based on scattering cancellation technique by realizing near 180 degrees reflection phase difference between two neighboring chessboard submeta-atoms. Thanks to the architecture of the two reflectors, the proposed antenna exhibits high gain and low profile simultaneously according to image theory. For verification, a planar CP Cassegrain antenna, excited by a left-handed CP (LCP) planar helical antenna, is numerically studied, fabricated, and experimentally measured. Numerical results are in good agreement with the experimental ones, showing a peak right-handed CP (RCP) gain of 26.6 dBi at 12.6 GHz. Furthermore, the backward monostatic RCS of the antenna is dramatically reduced over -10 dB in a broad bandwidth from 8.4 to 15.7 GHz when it is illuminated by an LCP planar wave. Our proposed Cassegrain antenna features simultaneously broadband, high gain, low profile, and low RCS, providing a new avenue to low-profile CP reflectarrays with invisibility.
摘要：
FeP2 and P are promising anode material for lithium and sodium ion storage, due to the high theoretical capacity. However, poor electric conductivity and severe volume expansion limit its actual performance. Herein, we prepared a flexible self-supporting anode material which is consist of FeP2, P and C heterostructure nanofibers with diameter of 150.0-200.0 nm named FeP2 & nbsp;@CNs-700. Here, well-dispersed FeP2 & nbsp;nanoparticles and amorphous phosphorus are confined in carbon nanofiber skeleton, which enhance the material's electron/ion transport and structure stability. As a result, The FeP2 & nbsp;@CNs-70 0 exhibits a high capacity (1132.2 mAh g & nbsp;(- 1) at 0.1 A g & nbsp;(- 1)& nbsp;for lithium ion batteries, 680.8 mAh g & nbsp;(- 1 & nbsp;)at 0.1 A g & nbsp;(- 1)& nbsp;for sodium ion batteries), excellent cycle stability (a capacity retention of 84.6% at 0.5 A g & nbsp;(- 1)& nbsp;after 500 cycles for LIBs, 300.1 mAh g & nbsp;(- 1)& nbsp;at 1.0 A g & nbsp;(- 1)& nbsp;after 400 cycles for SIBs), outstanding rate performance (461.2/227.9 mAh g & nbsp;(- 1)& nbsp;at high current density of 10.0 A g & nbsp;(- 1)& nbsp;for Li/Na-ion battery, respectively) and high initial coulombic efficiency (87.3% for LIBs and 74.5% for SIBs), indicating a promising candidate for high capacity anodes.& nbsp;(c) 2021 Elsevier Ltd. All rights reserved.
期刊：
Fuzzy Sets and Systems,2022年426:27-45 ISSN：0165-0114
通讯作者：
Li, Long
作者机构：
[Li, Long] Hengyang Normal Univ, Coll Math & Stat, Hengyang, Hunan, Peoples R China.;[Long, Zuqiang] Hengyang Normal Univ, Coll Phys & Elect Engn, Hengyang, Hunan, Peoples R China.;[Ying, Hao] Wayne State Univ, Dept Elect & Comp Engn, Detroit, MI 48202 USA.;[Qiao, Zhijun] Univ Texas Rio Grande Valley, Dept Math, Edinburg, TX 78539 USA.
通讯机构：
[Li, Long] H;Hengyang Normal Univ, Coll Math & Stat, Hengyang, Hunan, Peoples R China.
通讯机构：
[Yanliang Tan] C;College of Physics and Electronic Engineering, Hengyang Normal University, China
关键词：
Radon concentration in water;RAD7;H2O accessory;Bubbling method;Conversion coefficient;Drying tube
摘要：
Durridge Company offers RAD7 and H2O accessory to measure the radon concentration in water based on bubbling method. There are two types of small sample bottles: 40 mL and 250 mL. The company also provided a big bottle with the volume of 2500 mL to measure the radon concentration in water. For the 40 mL and 250 mL sample bottles, the conversion coefficients are 25 and 4, respectively. The small drying tube of water accessory contains only 30 g desiccant, which makes it inconvenient to measure for a long time and needs to be replaced frequently. Besides, the 2500 mL sample bottle with big drying tube needs longer response time. In this paper, a big drying tube with long lifetime is utilized to measure the radon concentration in water. Generally, the response time and the sensitivity depend on the volume of the sample bottles and the gas circuit, so it is important to obtain the conversion coefficients under different conditions to meet different measurement demands. A novel model is proposed for describing the radon concentration in the gas circuit to obtain the con -version coefficients for any volume of sample bottle and drying tube. By choosing the appropriate time of bubbling and measuring, this model can be utilized to obtain the radon concentration in water.
摘要：
A uranium tailing pond in southern China is the largest in Asia. For historical reasons, uranium tailings stored in the pond have been in an acidic environment for a long time, which has caused great difficulties for decommissioning treatment of the pond. In this study, uranium tailings were taken from the beach surface of the pond as the research object. Then, 11 kinds of solidified samples of uranium tailings with different compositional ratios were prepared using water glass and sodium hydroxide, as alkali activators, and mixed with metakaolin, fly ash, and PVA or basalt fibers. The resulting solidified samples were examined in terms of microscopic characterization, compressive strength, tensile strength, resistivity, and U(VI) leaching. The results showed that, with increased fiber content, the compressive strength of samples first increased and then decreased, while the tensile strength increased continuously. The body volume resistivities first increased and then decreased and, with increased time, the leaching rate decreased continuously and finally tended to stabilize. The compressive strength and volume resistivity of samples were negatively correlated with the U(VI) leaching rate and cumulative leaching fraction. Considering the physical mechanics and U(VI) leaching resistance properties of these bodies, the best fiber proportion was concluded to be the addition of 0.2-wt% PVA fiber and 0.6-wt% basalt fiber.
作者机构：
[Jiang, Xi; Wang, Xinwen; Tang, Shiqing] Hengyang Normal Univ, Coll Phys & Elect Engn, Hengyang 421002, Peoples R China.;[Wang, Xinwen] Hunan Normal Univ, Key Lab Low Dimens Quantum Struct & Quantum Contr, Changsha 410081, Peoples R China.;[Zhao, Xingdong] Henan Normal Univ, Sch Phys, Xinxiang 453000, Henan, Peoples R China.
通讯机构：
[Xinwen Wang] K;Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education, Hunan Normal University, Changsha 410081, China<&wdkj&>College of Physics and Electronic Engineering, Hengyang Normal University, Hengyang 421002, China<&wdkj&>Author to whom correspondence should be addressed.
摘要：
We propose a theoretical model for realizing a photonic two-qubit phase gate in cavity QED using a one-step process. The fidelity and probability of success of the conditional quantum phase gate is very high in the presence of cavity decay. Our scheme only employs one two-level atom, and thus is much simpler than other schemes involving multi-level atoms. This proposal can also be applied to generate two-mode squeezed states; therefore, we give three examples, i.e., the two-mode squeezed vacuum state, two-mode squeezed odd coherent state, and two-mode squeezed even coherent state, to estimate the variance of Duan’s criterion when taking into account cavity decay. It is shown that the variance is smaller than 2 for the three squeezed states in most cases. Furthermore, we utilize logarithmic negativity to measure the entanglement, and find that these squeezed states have very high degrees of entanglement.
作者机构：
[Tang, Zhenkun; Deng, Xiaohui] Hengyang Normal Univ, Coll Phys & Elect Engn, Hengyang 421002, Hunan, Peoples R China.
通讯机构：
[Deng, X.] C;College of Physics and Electronic Engineering, China
摘要：
The ultra-wide single spin states are of importance for ideal magnetic storage materials and spin injection sources. Here, a new type of CrOX (X= Cr, Br, I) monolayer has been revealed. We find that the basic constructive units for such new monolayers are four-coordinated, almost never being reported until now. More interestingly, they are half-metals and have an ultra-wide single spin channel in their electronic band structures. Monte Carlo simulations show that the Curie temperatures of three monolayers are relatively low, however they can be enhanced to exceed the liquid nitrogen temperature under strain or hole doping. The four-coordinated Cr compounds predicted here may open a new windows for exploring high spin-polarized half-metals. Copyright (C) 2022 EPLA
通讯机构：
[Li, L ] H;Hengyang Normal Univ, Coll Comp Sci & Technol, Hengyang 421002, Peoples R China.;Hengyang Normal Univ, Hunan Prov Key Lab Intelligent Informat Proc & Ap, Hengyang 421002, Peoples R China.
关键词：
Differential power analysis;Hamming weight;Ghost peaks;AES
摘要：
Differential power analysis (DPA) is disturbed by ghost peaks. There is a phenomenon that the mean absolute difference (MAD) value of the wrong key is higher than the correct key. We propose a compressed key guessing space (CKGS) scheme to solve this problem and analyze the AES algorithm. The DPA based on this scheme is named CKGS-DPA. Unlike traditional DPA, the CKGS-DPA uses two power leakage points for a combined attack. The first power leakage point is used to determine the key candidate interval, and the second is used for the final attack. First, we study the law of MAD values distribution when the attack point is AddRoundKey and explain why this point is not suitable for DPA. According to this law, we modify the selection function to change the distribution of MAD values. Then a key-related value screening algorithm is proposed to obtain key information. Finally, we construct two key candidate intervals of size 16 and reduce the key guessing space of the SubBytes attack from 256 to 32. Simulation experimental results show that CKGS-DPA reduces the power traces demand by 25% compared with DPA. Experiments performed on the ASCAD dataset show that CKGS-DPA reduces the power traces demand by at least 41% compared with DPA.
通讯机构：
[Javed Rehman; Kamel Eid] A;Authors to whom correspondence should be addressed.<&wdkj&>Gas Processing Center (G.P.C.), College of Engineering, Qatar University, Doha 2713, Qatar<&wdkj&>Authors to whom correspondence should be addressed.<&wdkj&>Department of Physics, Balochistan University of Information Technology, Engineering and Management Sciences (BUITEMS), Quetta 87300, Baluchistan, Pakistan
关键词：
V4C3;MXene;Li-ion battery;Na-ion battery;electrochemical energy storage;DFT
摘要：
Li-ion batteries (LIBs) and Na-ion batteries (SIBs) are deemed green and efficient electrochemical energy storage and generation devices; meanwhile, acquiring a competent anode remains a serious challenge. Herein, the density-functional theory (DFT) was employed to investigate the performance of V4C3 MXene as an anode for LIBs and SIBs. The results predict the outstanding electrical conductivity when Li/Na is loaded on V4C3. Both Li2xV4C3 and Na2xV4C3 (x = 0.125, 0.5, 1, 1.5, and 2) showed expected low-average open-circuit voltages of 0.38 V and 0.14 V, respectively, along with a good Li/Na storage capacity of (223 mAhg(-1)) and a good cycling performance. Furthermore, there was a low diffusion barrier of 0.048 eV for Li0.0625V4C3 and 0.023 eV for Na0.0625V4C3, implying the prompt intercalation/extraction of Li/Na. Based on the findings of the current study, V4C3-based materials may be utilized as an anode for Li/Na-ion batteries in future applications.
期刊：
Physica E-Low-Dimensional Systems & Nanostructures,2022年135:114978 ISSN：1386-9477
通讯作者：
Liu, Zhaosen
作者机构：
[Liu, Zhaosen] Hengyang Normal Univ, Coll Phys & Elect Engn, Hengyang 421002, Peoples R China.;[Yang, Hongxin] Chinese Acad Sci, Ningbo Inst Mat Technol & Engn, Div Magnet Mat & Devices, Ningbo 315201, Peoples R China.;[Yang, Hongxin] Univ Chinese Acad Sci, Ctr Mat Sci & Optoelect Engn, Beijing 100049, Peoples R China.
通讯机构：
[Liu, Zhaosen] H;Hengyang Normal Univ, Coll Phys & Elect Engn, Hengyang 421002, Peoples R China.
关键词：
Optimized quantum Monte Carlo method;Antiferromagnetic skyrmion crystal;Two-dimensional square magnet
摘要：
The formations of individual antiferromagnetic (AF) skyrmions and AF skyrmionic lattices on two-dimensional (2D) magnets with square crystal structure are debatable in recent years, for only an isolated skyrmion can be generated in such systems if classical Monte Carlo (CMC) method is employed. For the sake, we apply here an optimized quantum Monte Carlo approach to a 2D square magnet where the AF Heisenberg exchange (HE) and Dzyaloshinskii-Moriya (DM) interactions co-exist. Consequently, the computing program converges to the equilibrium states with appreciable computational speed, and the results obtained in the last one iteration are able to accurately produce well symmetric and periodic AF skyrmionic lattices (SLs) at elevated temperatures when a considerably strong external magnetic field is exerted perpendicular to the 2D monolayer. Moreover, each of these AF SLs can be decomposed into two almost identical ferromagnetic (FM) SLs, and the distribution of topological charge density also forms symmetric lattice with the same periodicity as the AF SL, dividing the AF SL into several areas of distinct spin configurations. The reasons why the OQMC approach can work beyond CMC method are explained in the Discussion Section.
