通讯机构：
[Zhang, C ] W;Wuhan Polytech Univ, Sch Elect & Elect Engn, Wuhan 430048, Peoples R China.
关键词：
personal audio system;sound field control;acoustic contrast;reconstruction error;array effort
摘要：
A personal audio system has a wide application prospect in people’s lives, which can be implemented by sound field control technology. However, the current sound field control technology is mainly based on sound pressure or its improvement, ignoring another physical property of sound: particle velocity, which is not conducive to the stability of the entire reconstruction system. To address the problem, a sound field method is constructed in this paper, which minimizes the reconstruction error in the bright zone, minimizes the loudspeaker array effort in the reconstruction system, and at the same time controls the particle velocity and sound pressure of the dark zone. Five unevenly placed loudspeakers were used as the initial setup for the computer simulation experiment. Simulation results suggest that the proposed method is better than the PM (pressure matching) and EDPM (eigen decomposition pseudoinverse method) methods in the bright zone in an acoustic contrast index, the ACC (acoustic contrast control) method in a reconstruction error index, and the ACC, PM, and EDPM methods in the bright zone in a loudspeaker array effort index. The average array effort of the proposed method is the smallest, which is about 9.4790, 8.0712, and 4.8176 dB less than that of the ACC method, the PM method in the bright zone, and the EDPM method in the bright zone, respectively, so the proposed method can produce the most stable reconstruction system when the loudspeaker system is not evenly placed. The results of computer experiments demonstrate the performance of the proposed method, and suggest that compared with traditional methods, the proposed method can achieve more balanced results in the three indexes of acoustic contrast, reconstruction error, and loudspeaker array effort on the whole.
通讯机构：
[Bin Guo] D;Department of Physics, Wuhan University of Technology, Wuhan 430070, China
关键词：
Many -body localization;Two-qubit nonlocality;Multipartite nonlocality;Energy level statistics;Entanglement entropy
摘要：
Characterizing the many-body localization (MBL) transition and revealing its inherent mechanisms from the ergodic phase to the localized phase is an increasing interest issue. In this paper, we use quantum nonlocality, the hierarchy of multipartite correlations, to identify the MBL transition in an XXZ spin chain with random on-site magnetic fields. We use the shift-invert exact diagonalization method to explore the properties of two-qubit nonlocality and multipartite nonlocality in the many-body localized system. We then use their first derivatives to estimate the critical disorder strength, which is found to be range in hc/J is an element of [3, 4]. Correspondingly, two quantities and their first derivatives, the energy level statistics and the half-chain entanglement entropy that are promising for the study of the MBL transition, are also investigated and as comparisons to quantum nonlocality.(c) 2023 Elsevier B.V. All rights reserved.
通讯机构：
[Bin Guo] D;Department of Physics, Wuhan University of Technology, Wuhan 430070, People's Republic of China
关键词：
energy spectra;extended Ising model;nonlocality;topological quantum phase transitions;winding number
摘要：
We use two-site quantum nonlocality to identify the topological quantum phase transitions (TQPTs) of the extended Ising model driven by varying system parameters. We investigate how the system parameters, including the anisotropies of the nearest-neighbor and the next-nearest-neighbor spin pairs, the transverse magnetic field, and the three-spin interaction, affect the quantum nonlocality. We show that the nonlocality cannot mark any TQPTs while its first derivative can perfectly characterize the TQPTs. By making the influences of the thermal fluctuations and the site distance of spin pairs on the critical behavior of the TQPTs analysis, we show that the sufficiently low temperature has a slight impact on the features of nonlocality and its first derivative while the site distance of spin pairs can significantly alter the properties of nonlocality and its first derivative. We further present the energy spectra and the trajectories of the winding vectors of the model to demonstrate that the quantum nonlocality can be employed to successfully signalize the TQPTs.
摘要：
Pompon-like WS2 nanostructure-based gas sensor was fabricated, and the sensing performance with micromechanism to SF6 decompositions was discussed. At optimal working temperature, the sensor experiences resistance increasing for all four SF6 decompositions (SO2, SOF2, SO2F2, and H2S). At low concentration (0-50 ppm), the sensor shows high linearity (R-2 > 0.99), and the rank of the sensitivity is: H2S>SO2>SO2F2>SOF2. Furthermore, the first-principles results indicate that the different sensitivity is derived from the chemical interactions and electron transfer between the adsorbed molecule and the edge structures of WS2. This work gives experimental and theoretical support of transition metal dichalcogenide (TMDC)-based gas sensor to detect SF6 decompositions and provides insights to design high-performance TMDC-based gas sensor from theoretical aspect.
通讯机构：
[Zhao-Yu Sun] S;School of Electrical and Electronic Engineering, Wuhan Polytechnic University, Wuhan, China
关键词：
The European Physical Journal B;Condensed Matter;Complex Systems;journal;EPJ
摘要：
Multipartite nonlocality is a measure of multipartite quantum correlations. In this paper, we investigate multipartite nonlocality in a spin-
$$\frac{1}{2}$$
XXZ model on a one-dimensional (1D) infinite-size zigzag lattice. In the ground states, the model can undergo topological-type quantum phase transitions (QPTs) between a singlet dimer (SD) phase and an even-parity dimer (ED) phase. Two nonlocality measures
$${\mathcal {S}}_o$$
(defined on the odd-bond subchains) and
$${\mathcal {S}}_e$$
(defined on the even-bond subchains) are used to characterize these topological-type QPTs. Both measures show some kinds of singularity (i.e., a discontinuity of the measure or the divergence of its derivative) in the QPTs. Furthermore, in the SD phase and in the vicinity of critical regions,
$${\mathcal {S}}_o$$
is relatively large, and in most regions of the ED phase,
$${\mathcal {S}}_o$$
is nearly zero. Thus, similar to order parameters in traditional phase transitions,
$${\mathcal {S}}_o$$
is an effective physical quantity to characterize these topological-type QPTs. Scaling behavior of the nonlocality measure is also discussed.
关键词：
Flexible electronics;Transparent conducting oxide;Mica;Strain tuning;Complex oxide;Tunable transport behaviors;SrVO3
摘要：
Strongly correlated metal strontium vanadate (SrVO3) was recently proposed to be used as a promising transparent conductor. Control of the optical and electrical properties of SrVO3 thin films using external stimuli is highly desired for most practical applications. Herein, flexible heteroepitaxial SrVO3 films on mica substrates were synthesized in a simple process using a pulsed laser deposition (PLD) method, showing high optical transparency and excellent electrical conductivity. The experiments demonstrate that the resistivity of flexible SrVO3 films depends strongly on the applied mechanical strain whereas the optical transmittance is retained during the bending tests. It is shown that two distinctly different resistivity values are switched back and forth repeatedly upon applying or removing a mechanical bending strain. The measured resistivity increases with increasing mechanical strain, which is attributed to the enhanced residual resistivity present in flexible SrVO3/mica membranes upon the application of a mechanical strain. We demonstrate that mechanical strain allows effective tuning of electrical conductivity in epitaxial SrVO3/ mica membranes. The transparent conducting oxide SrVO3/mica membranes with highly tunable electrical conductivity show great potential for future flexible electronics and photovoltaics. (c) 2021 Elsevier B.V. All rights reserved.
通讯机构：
[Dachang Chen] S;School of Electrical and Electronic Engineering, Wuhan Polytechnic University, Wuhan, 430023, China
关键词：
Density functional theory;Janus HfSeTe;Single vacancy;Gas adsorption
摘要：
Janus transitional metal dichalcogenides (TMDCs) have raised wide attraction because of its unique physical and chemical properties. This work focuses on the effect of single surface vacancy (Se and Te vacancy) on adsorption and sensing properties of Janus HfSeTe monolayer to several hazardous gases (CO, H2S, NH3, NO, NO2, and SO2). The adsorption structures, adsorption energy, charge transfer, electronic properties and work function are calculated using density functional theory. It is found that different surface vacancy (Se or Te vacancy) brings different adsorption behavior, and the introduction of vacancy significantly enhances the chemical interactions between Janus HfSeTe monolayer and adsorbed gases. The adsorption energy and charge transfer obviously increase for all these molecules compared to the adsorption on pristine HfSeTe monolayer. More notably, the adsorption of CO, NO, NO2 and SO2 brings new chemical bond formation, and the atomic density of states (DOS) suggests that there exist states overlapping between dangling Hf atom and atom in molecule. In addition, H2S and NH3 adsorptions make the work function decrease while other adsorptions lead to the risen of work function. Based on the distinguished adsorption properties and different degree of work function variation, Janus HfSeTe is a potential candidate in hazardous gas scavenger and sensing material.
期刊：
Journal of Materials Science,2022年57(35):16820-16829 ISSN：0022-2461
通讯作者：
Li Shaozhen<&wdkj&>Liu Bin
作者机构：
[Zhao Xu; Chen Luocheng; Li Shaozhen] Wuhan Polytech Univ, Sch Elect & Elect Engn, Wuhan 430023, Hubei, Peoples R China.;[Mei Yunjun] Wuhan Polytech Univ, Sch Chem & Environm Engn, Wuhan 430023, Hubei, Peoples R China.;[Chen Luocheng] Hubei Sino Australian Nano Mat Technol Co Ltd, Guangshui 432700, Peoples R China.;[Guo Hongxuan] Southeast Univ, Key Lab MEMS, Minist Educ, Sch Elect Sci & Engn,SEU FEI Nano Pico Ctr, Nanjing 210096, Peoples R China.;[Liu Bin] Jiangsu Ocean Univ, Coll Pharm, Jiangsu Key Lab Marine Pharmaceut Compound Screen, Lianyungang 222005, Peoples R China.
通讯机构：
[Li Shaozhen] S;[Liu Bin] J;School of Electrical and Electronic Engineering, Wuhan Polytechnic University, Wuhan, China<&wdkj&>Jiangsu Key Laboratory of Marine Pharmaceutical Compound Screening, College of Pharmacy, Jiangsu Ocean University, Lianyungang, China
摘要：
ZnMoO4 nanoparticles with two different morphologies were successfully synthesized by the industrial dry method. Both nano-ZnMoO4 belong to alpha crystalline phase, and the valence state of Mo was verified to be + 6. The polyhedral-shaped particles and a mixture of polyhedral and rod-shaped particles exists, respectively. The average size of ZnMoO4 nanoparticles with polyhedral structure was 50 nm in diameter, while the diameter of the cross-section of ZnMoO4 nanoparticles (NPs) with rod-like structure was less than 50 nm. To evaluate the antibacterial properties of two materials, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of two kinds of nano-ZnMoO4 against staphylococcus aureus were determined using an agar medium. The results showed that the MIC and MBC values of polyhedral nano-ZnMoO4 were 20 ppm and 40 ppm; the MIC and MBC values of rod-shaped and polyhedral hybrid nano-ZnMoO4 were 10 ppm and 20 ppm, respectively. The antibacterial effect of both nanoparticles was better than that of conventional ZnMoO4 with the size above 1 mu m at the concentration of 200 ppm. This confirms the crystalline structure in relation to the crystal size/morphology and the concentration of powder in suspension can influence on the antibacterial efficiency. Furthermore, these two shaped nano-ZnMoO4 samples had different atomic percentages, so different spatial hinge structures were the important reason for the unequal antibacterial performance of these shaped nano-ZnMoO4 powder.
摘要：
We propose a transfer-matrix theory to reveal the hidden structure in the multipartite nonlocality operators in one-dimensional (1D) quantum chains. The theory offers a unified description for the scaling behaviors of multipartite quantum nonlocality in general 1D quantum lattices. Furthermore, in order to figure out the hierarchy of multipartite nonlocality for infinite-size chains, powerful transfer-matrix-based algorithms are proposed. In quantum critical regions, the algorithms converge much faster than the traditional approach.
期刊：
Journal of Colloid and Interface Science,2022年613:435-446 ISSN：0021-9797
通讯作者：
Zhang, C;Singh, CV
作者机构：
[Zhang, Cong; Zhang, C; Chen, Dachang] Wuhan Polytech Univ, Sch Elect & Elect Engn, Wuhan 430023, Peoples R China.;[Mukherjee, Sankha] Indian Inst Technol Kharagpur, Dept Met & Mat Engn, Kharagpur 721302, W Bengal, India.;[Mukherjee, Sankha; Singh, Chandra Veer] Univ Toronto, Dept Mat Sci & Engn, Toronto, ON M5S 3E4, Canada.;[Singh, Chandra Veer] Univ Toronto, Dept Mech & Ind Engn, Toronto, ON M5S 3G8, Canada.;[Li, Yi] Wuhan Univ, Sch Elect Engn & Automat, Wuhan 430072, Peoples R China.
通讯机构：
[Zhang, C ] W;[Singh, CV ] U;Wuhan Polytech Univ, Sch Elect & Elect Engn, Wuhan 430023, Peoples R China.;Univ Toronto, Dept Mat Sci & Engn, Toronto, ON M5S 3E4, Canada.;Univ Toronto, Dept Mech & Ind Engn, Toronto, ON M5S 3G8, Canada.
关键词：
Cathode material;First principles;Lithium-sulfur battery;Two-dimensional metal organic framework
摘要：
Lithium-sulfur (Li-S) batteries are considered as new generation of energy storage which offer costeffectiveness and high energy density. However, their commercialization is restricted due to a host of challenges associated with the cathode material which usually contains sulfur with several drawbacks, including a low electronic conductivity of sulfur, the 'shuttle effect', and a large volume expansion during discharge. Herein, a novel two-dimensional porphyrin-like square metal organic framework (MOF) was explored as a promising cathode material using first principles density function theory (DFT) assisted by genetic global search. The DFT results show that, among 7 kinds of transition-metal organic framework (TM-MOF), only V-MOF and Ru-MOF is found to possess considerable chemical interactions with S8 and lithium polysulfides (LiPSs) in both vacuum and in electrolytic solvents, demonstrating distinguishable anchoring performance. The genetic global search and further DFT calculations indicate that the lithiation process on V-MOF exhibited a nearly constant open-circuit voltage of about 1.92 V to 1.95 V, and the theoretical energy density could reach up to 1469 Wh kg(-1) when lithiation of S8 is considered on both sides of the substrate. The volume expansion of V-MOF during discharge is found to be about 34%, much smaller than 80% for solid sulfur. The band structure and density of states of V-MOF suggest metallic properties or a small band gap for bare surface or during the lithiation process. These results indicate that two-dimensional (2D) V-MOFs can serve as high-performance cathode material with distinguished anchoring performance to block polysulfide dissolution and thereby reduce the 'shuttle effect', and help attain ultra-high energy density. Our work points the way for designing and providing experimental realization of 2D layered materials applied in cathode with high energy density and stability. (C) 2021 Elsevier Inc. All rights reserved.
摘要：
Urban sound event detection can automatically preload relevant information for a robot to ensure that it can be applied to various scene-activity tasks. To address the limitations of timbre similarity and scene recognition by audio collection devices, a fusion model based on the self-attention mechanism is proposed in this paper. The model consists of scattering transform and self-attention model. The scattering transform computes modulation spectrum coefficients of multiple orders through cascades of wavelet convolutions and modulus operators. It is learnable compared with Mel-scale Frequency Cepstral Coefficients (MFCC), and can be used to better restore the semantic features of some sound scenes with similar timbres. The transformer has an outstanding effect on Natural Language Processing (NLP) owing to its self-attention mechanism. In this paper, the self-attention mechanism in its encoder was used in the model, mainly to make the feature granularity consistent to refine the features. In addition, Focal Loss function was adopted in the model to curb the sample distribution imbalance. The Google Command and ESC-50 were used to supplement the scene categories of dataset UrbanSound8K. The model parameters of the learnable filters that performed well on the dataset UrbanSound8K were preserved to fine-tune the other two datasets with insufficient data volume and more target categories. The length of slice duration was further explored the in the model. The experimental results show that the model can achieve better performance in a large range of scene models.
摘要：
Exploring high-performance sensing materials aimed at dissolved gases in transformer oil is of crucial importance to guarantee the safe and stable operation of power transformer. This study investigates the adsorption and sensing of five kinds of dissolved gas molecules (H2, CO, CH4, C2H2, and C2H4) on single Pd atom doped Janus HfSeTe monolayer (Pd-HfSeTe). The adsorption structure, adsorption energy, electron transfers, density of states (DOS), band structure, and work function are calculated. The results demonstrate that single Pd atom has much larger binding energy on HfSeTe surface compared to bulk Pd, and shows high thermal stability at 500 K. In addition, the doping of Pd significantly enhances the adsorption strength of CO, C2H2, and C2H4. The electronic properties illustrate that the band gap experiences apparent increase for CO adsorption on Pd site for both Se and Te surface, and there shows obvious overlapping of Pd 4d and C 2p orbitals in atomic DOS for CO, C2H2, and C2H4 adsorption. Furthermore, taking electronic properties, work function, and occupation function into consideration, Pd-HfSeTe can detect C2H4 with higher selectivity as both resistance-type and work-function type gas sensor. This theoretical study allows novel opinions of Janus transitional-metal dichalcogenides (TMDCs) doped with single transition-metal atom as sensing materials for gas detection in numerous application area.
摘要：
Epitaxially orthorhombic DyMnO3 films were deposited on Nb:SrTiO3 (100) substrates by pulsed laser deposition. DyMnO3 film with weakly ferromagnetic at low temperatures, probably resulting from the strained Mn-spin configuration in the ab plane, is observed. The dielectric change under the magnetic field from 0 to 9 T at around 16 K indicates the magnet-dielectric effect, which should be related with Mn3+ spin reorientation and magneto-elastically inducing lattice modulation under DM (Dzyaloshinsky-Moriya) interaction in perovskite rare-earth manganites RMnO3.
摘要：
To search for stable structural units of low dimensional dilute magnetic semiconductor materials, Cr-doped and C/N co-doped Zn12Se12 clusters were investigated with first principle all electron calculations. In geometry-optimized Cr2Zn10Se12 nanoclusters, two Cr atoms substituted the nearest Zn atom sites in the rhombus part. Energy analysis indicated that the ground state of Cr2Zn10Se12 nanoclusters tends to be a weak ferromagnetic coupling state originating from the electron hybridization of the Cr-3d, Cr-4s and Se-4p orbitals. In C/N co-doped Cr2Zn10CSe11/Cr2Zn10NSe11 nanoclusters, the C/N atoms prefer to occupy the Se atom sites to form Cr-C-Cr/Cr-N-Cr bonding. The ground state tends to be a slightly stronger ferromagnetic coupling state, with Cr-3d and C/N-2p orbitals being the main contributors to the magnetism of the nanoclusters. With the introduction of C/N co -doped atoms, the strong electron hybridization among C/N-2p, Cr-3d and Cr-4s orbitals contributed to the enhanced stability of ferromagnetic ground state. For all the Cr2Zn10Se12 and C/N co-doped Cr2Zn10CSe11/Cr2Zn10NSe11 nanoclusters, hole-mediated ferromagnetic coupling between Cr atoms was found to improve the ferromagnetic stability, which may provide some guidance for the exploration of new materials.
摘要：
A new theoretical scheme for two-dimensional (2D) electromagnetically induced grating (EIG) is proposed in a three-level $\Xi$-type atomic system. The system is driven by a weak probe field and two position-dependent coupling fields--a 2D standing-wave field and a vortex field. Due to lopsided spatial modulation of the vortex Laguerre-Gaussian field, the weak probe light could be diffracted into different domains and asymmetric 2D EIG is formed. The result shows that the diffraction patterns and efficiency could be effectively modulated by the azimuthal parameter of the vortex field. Also, the system parameters such as the probe field detuning, the intensity of the vortex field, and the interaction length could be used to regulate the diffraction properties of the 2D EIG effectively. The scheme of asymmetric 2D EIG may have some potential application in all-optical information processing and the design of quantum devices.
