作者机构：
[Guo, Siqi; Cheng, Ningyan; Ge, Binghui; Zhang, Jialin] Anhui Univ, Inst Phys Sci & Informat Technol, Informat Mat & Intelligent Sensing Lab Anhui Prov, Key Lab Struct & Funct Regulat Hybrid Mat,Minist, Hefei 230601, Peoples R China.;[Ren, Long; Ji, Yuan] Wuhan Univ Technol, Int Sch Mat Sci & Engn, State Key Lab Adv Technol Mat Synth & Proc, Wuhan 430070, Peoples R China.;[Liu, Huating] Wuhan Polytech Univ, Sch Elect & Elect Engn, Wuhan 430023, Peoples R China.;[Yang, Ming] Beihang Univ, Sch Phys, Beijing 100191, Peoples R China.
通讯机构：
[Cheng, NY; Ge, BH ] A;[Ren, L ] W;Anhui Univ, Inst Phys Sci & Informat Technol, Informat Mat & Intelligent Sensing Lab Anhui Prov, Key Lab Struct & Funct Regulat Hybrid Mat,Minist, Hefei 230601, Peoples R China.;Wuhan Univ Technol, Int Sch Mat Sci & Engn, State Key Lab Adv Technol Mat Synth & Proc, Wuhan 430070, Peoples R China.
关键词：
carbothermal reduction;electrocatalysts;in situ;structure evolution;transmission electron microscopy
摘要：
Atomic understanding of a chemical reaction can realize the programmable design and synthesis of desired products with specific compositions and structures. Through directly monitoring the phase transition and tracking the dynamic evolution of atoms in a chemical reaction, in situ transmission electron microscopy (TEM) techniques offer the feasibility of revealing the reaction kinetics at the atomic level. Nevertheless, such investigation is quite challenging, especially for reactions involving multi-phase and complex interfaces, such as the widely adopted carbothermal reduction (CTR) reactions. Herein, in-situ TEM is applied to monitor the CTR of Co3O4 nanocubes on reduced graphene oxide nanosheets. Together with the first-principle calculation, the migration route of Co atoms during the phase transition of the CTR reaction is revealed. Meanwhile, the interfacial edge-dislocations/stress-gradient is identified as a result of the atomistic diffusion, which in turn can affect the morphology variation of the reactants. Accordingly, controllable synthesis of Co-based nanostructure with a desirable phase and structure has been achieved. This work not only provides atomic kinetic insight into CTR reactions but also offers a novel strategy for the design and synthesis of functional nanostructures for emerging energy technologies.
期刊：
Surfaces and Interfaces,2023年40:103145 ISSN：2468-0230
通讯作者：
Li, SZ;Gao, Jinwei;Wu, SJ
作者机构：
[Zhao, Xu; Li, Shaozhen] Wuhan Polytech Univ, Sch Elect & Elect Engn, Wuhan 430023, Peoples R China.;[Wu, Sujuan; Gao, Jinwei; Wu, SJ; Wu, Shengcheng; Yun, Tong; Yang, Jiajun] South China Normal Univ, Inst Adv Mat, South China Acad Adv Optoelect, Guangzhou 510006, Peoples R China.;[Wu, Sujuan; Gao, Jinwei; Wu, SJ; Wu, Shengcheng; Yun, Tong; Yang, Jiajun] South China Normal Univ, South China Acad Adv Optoelect, Guangdong Prov Key Lab Quantum Engn & Quantum Mat, Guangzhou 510006, Peoples R China.
通讯机构：
[Gao, JW; Wu, SJ ] S;[Li, SZ ] W;Wuhan Polytech Univ, Sch Elect & Elect Engn, Wuhan 430023, Peoples R China.;South China Normal Univ, Inst Adv Mat, South China Acad Adv Optoelect, Guangzhou 510006, Peoples R China.;South China Normal Univ, South China Acad Adv Optoelect, Guangdong Prov Key Lab Quantum Engn & Quantum Mat, Guangzhou 510006, Peoples R China.
关键词：
Dual-additive;Low-temperature process;Stability;Carbon-basedCsPbIBr2 Perovskite solar cells
摘要：
The internal non-radiative recombination and high trap-state density (Ntrap) in perovskite layer have severely limited the progress of low-temperature processed CsPbIBr2 perovskite solar cells (PSCs). In this work, cesium acetate (CsAc) and hydrogen lead triiodide (HPbI3) dual-additives are employed to tune the properties of CsPbIBr2 film prepared by low-temperature process. The CsAc material is used to modify CsPbIBr2 surface and optimize the CsPbIBr2/carbon electrode interface, while HPbI3 additive is employed to dope perovskite layer. The dual-additive strategy is used to optimize the microstructure and regulate the optoelectrical characteristics of carbon-based CsPbIBr2 PSCs. It is found that CsAc can passivate the vacancy defect of Br−, reduce the energy loss (Eloss) and enhance the open-circuit voltage (Voc) of PSCs. The HPbI3 additive works to optimize the crystallization process, resulting in the high-quality CsPbIBr2 films with better crystallinity and morphology. The modified films by CsAc and HPbI3 dual-additive demonstrate smaller band gap, better light absorption, reduced trap-state density (Ntrap) and suppressed carrier recombination. The optimized carbon-based PSCs modified by the dual-additive achieve a champion power conversion efficiency of 9.18% with a Voc of 1.334 V, more matched energy-level, reduced Eloss and promoted charge transfer. Moreover, the modified PSCs without encapsulation show improved long-term humid stability. Our work provides a facilitated method to prepare an efficient and stable CsPbIBr2 PSCs by low-temperature process.
关键词：
small object detection;multi-scale feature fusion;loss function;data augmentation;K-means plus plus
摘要：
The detection of traffic signs is easily affected by changes in the weather, partial occlusion, and light intensity, which increases the number of potential safety hazards in practical applications of autonomous driving. To address this issue, a new traffic sign dataset, namely the enhanced Tsinghua-Tencent 100K (TT100K) dataset, was constructed, which includes the number of difficult samples generated using various data augmentation strategies such as fog, snow, noise, occlusion, and blur. Meanwhile, a small traffic sign detection network for complex environments based on the framework of YOLOv5 (STC-YOLO) was constructed to be suitable for complex scenes. In this network, the down-sampling multiple was adjusted, and a small object detection layer was adopted to obtain and transmit richer and more discriminative small object features. Then, a feature extraction module combining a convolutional neural network (CNN) and multi-head attention was designed to break the limitations of ordinary convolution extraction to obtain a larger receptive field. Finally, the normalized Gaussian Wasserstein distance (NWD) metric was introduced to make up for the sensitivity of the intersection over union (IoU) loss to the location deviation of tiny objects in the regression loss function. A more accurate size of the anchor boxes for small objects was achieved using the K-means++ clustering algorithm. Experiments on 45 types of sign detection results on the enhanced TT100K dataset showed that the STC-YOLO algorithm outperformed YOLOv5 by 9.3% in the mean average precision (mAP), and the performance of STC-YOLO was comparable with that of the state-of-the-art methods on the public TT100K dataset and CSUST Chinese Traffic Sign Detection Benchmark (CCTSDB2021) dataset.
摘要：
The oscillatory potential well can cause the mass points in it to move chaotically, which can be considered as a physical mechanism of chaos generation. Based on this physical mechanism, the oscillatory multi-well potential with multi-concave is used to generate controllable multi-scroll chaotic attractors with multi-wing. These attractors have two kinds of topological units: scroll and wing. The topological structure of the attractor depends on the shape of the potential well, that is, the wells and the concaves correspond to the scrolls and wings of the attractor. By constructing potential wells with different shapes, we can obtain attractors with different topological structure. The number of scrolls and wings of the chaotic attractor can be controlled by the oscillation amplitude of the potential well and damping coefficient, that is, stronger oscillation or smaller damping allows the mass points to enter the higher potential wells or concaves, resulting in attractors with more scrolls or wings. As the number of scrolls or wings increases, the attractors become more complex, as expressed by Poincare & PRIME; maps and quantified by the Kaplan-Yorke dimensions. Kaplan-Yorke dimensions of attractors can be adjusted continuously from 2 to 3 by the two control parameters. Finally, the results are confirmed by Multisim simulation circuit and actual analog circuit.
通讯机构：
[Liu, HT ] W;[Liu, HT; Huang, ZY ] X;Wuhan Polytech Univ, Sch Elect & Elect Engn, Wuhan 430023, Peoples R China.;Xiangtan Univ, Sch Phys & Optoelect, Hunan Key Lab Micronano Energy Mat & Devices, Xiangtan 411105, Hunan, Peoples R China.;Hunan Univ, Hunan Key Lab Two Dimens Mat, Changsha 410082, Peoples R China.
关键词：
Janus transition metal dichalcogenides;heterostructures;electronic structure;multilayer
摘要：
The structure and electronic properties of bilayer, trilayer, and multilayer vertical Janus heterostructures are studied by first-principles calculation. By comparing the electronic structure of monolayer SMoS, monolayer SeMoS, and SMoS/SeMoS heterostructures, it has been found that, when SMoS forms heterostructures with more than two layers of Janus SeMoS, the band gap of the system changes from direct to indirect. In the Janus heterostructure system, significant charge transfer occurs between layers and a certain built-in electric field occurs. Due to the different contribution of Mo-d orbital coupling to CBM in different SeMoS layers, the band gap oscillates periodically with three layers of SeMoS. As the number of SeMoS layers in the heterostructure increases, the electrostatic potential difference and built-in electric field of the system increases continuously, resulting in the band gap value decreasing slowly. At the same time, the valence band offset value of the heterostructure constructed by SMoS and multilayer SeMoS decreases, and the conduction band offset value increases. These properties enrich the research and application of transition metal dichalcogenide-related heterostructures as optoelectronic and nanoelectronic devices.
摘要：
The state of angle cocks determines the air connectivity of freight trains, and detecting their state is helpful to improve the safety of the running trains. Although the current research for fault detection of angle cocks has achieved high accuracy, it only focuses on the detection of the closed state and non-closed state and treats them as normal and abnormal states, respectively. Since the non-closed state includes the fully open state and the misalignment state, while the latter may lead to brake abnormally, it is very necessary to further detect the misalignment state from the non-closed state. In this paper, we propose a coarse-to-fine localization method to achieve this goal. Firstly, the localization result of an angle cock is obtained by using the YOLOv4 model. Following that, the SVM model combined with the HOG feature of the localization result of an angle cock is used to further obtain its handle localization result. After that, the HOG feature of the sub-image only containing the handle localization result continues to be used in the SVM model to detect whether the angle cock is in the non-closed state or not. When the angle cock is in the non-closed state, its handle curve is fitted by binarization and window search, and the tilt angle of the handle is calculated by the minimum bounding rectangle. Finally, the misalignment state is detected when the tilt angle of the handle is less than the threshold. The effectiveness and robustness of the proposed method are verified by extensive experiments, and the accuracy of misalignment state detection for angle cocks reaches 96.49%.
关键词：
UAV;artificial potential field method;virtual target points;adaptive step size;path planning
摘要：
The obstacle avoidance system of a drone affects the quality of its flight path. The artificial potential field method can react quickly when facing obstacles; however, the traditional artificial potential field method lacks consideration of the position information between drones and obstacles during flight, issues including local minima, unreachable targets, and unreasonable obstacle avoidance techniques that lengthen flight times and consume more energy get encountered. Therefore, an improved artificial potential field method is proposed. First, a collision risk assessment mechanism was introduced to avoid unreasonable obstacle avoidance actions and reduce the length of unmanned aerial vehicle flight paths. Then, to solve the problem of local minimum values and unreachable targets, a virtual sub-target was set up and the traditional artificial potential field model was modified to enable the drone to avoid obstacles and reach the target point. At the same time, a virtual sub-target evaluation factor was set up to determine the reasonable virtual sub-target, to achieve a reasonable obstacle avoidance path compared to the traditional artificial potential field method. The proposed algorithm can plan a reasonable path, reduce energy consumption during flight, reduce drone turning angle changes in the path, make the path smoother, and can also be applied in complex environments.
通讯机构：
[Liu, XP ] W;Wuhan Polytech Univ, Sch Anim Sci & Nutr Engn, Wuhan 430023, Peoples R China.
关键词：
brown rice kernels;bonding parameters;discrete element;bonded particle model;orthogonal test
摘要：
Aiming to resolve the practical problem of brown rice kernels being easily broken due to overprocessing during processing (milling and polishing), brown rice kernels of Japonica rice, after hulling, were used as the research object in this study. Firstly, through a texture meter test, the discrete element bonding parameters (K-n is normal stiffness per unit area, K-tau is tangential stiffness per unit area, C-n is critical normal stiffness, C-tau is critical shear stiffness) were obtained. Secondly, a brown rice kernels' bonding particle model was established by EDEM, and then a second orthogonal rotational combination test was carried out to calibrate the discrete bonding parameters, K-n = 4.43 x 10(12) N/m(3), K-tau = 6.13 x 10(11) N/m(3), C-n = 2.55 x 10(7) Pa, and C-tau = 7.92 x 10(7) Pa. The error of parameter calibration was within 5%, and the results were able to reflect the actual situation more realistically. Finally, analysis of the crushing process of brown rice kernels showed that their ability to withstand shear damage was not as great as their pressure-bearing capacity. The design of the relevant mechanism and the setting of parameters should be based on the critical shear stiffness of brown rice kernels, and the actual shear force F-tau* set during the processing should be smaller than the theoretical critical shear force F-tau (F-tau* < F-tau = 9.11 N). This study can provide a theoretical basis for optimizing the key structure and operating parameters of rice milling machines and polishing machines to effectively solve the practical problem of increased crushing of brown rice kernels due to overprocessing.
通讯机构：
[Zhen Xu] S;School of Electrical and Electronic Engineering, Wuhan Polytechnic University, Wuhan 430023, China<&wdkj&>Author to whom correspondence should be addressed.
关键词：
wireless sensor networks;DV-Hop;cyclotomic method;weighted recursive least squares
摘要：
Location information is one of the crucial and essential elements for monitoring data in wireless sensor networks. The distance vector-hop (DV-Hop) localization algorithm is of practical importance in improving its localization performance. To achieve global optimization, a DV-Hop algorithm based on the cyclotomic method and weighted normalization, also known as CMWN-DV-Hop, is nominated in this paper. Therefore, the segmentation and weighting factors are introduced and normalized. The weighted recursive least-squares (WRLS) algorithm is chosen to compute the coordinates of the unknown nodes. The effects of various factors on this algorithm are tested, including the number of nodes, the anchor node ratio, and the communication radius. The simulation results show that the proposed algorithm has a super performance in reducing the localization error.
摘要：
We investigate the many-body localization (MBL) transitions in a spin-1/2 Heisenberg chain with an on-site random magnetic field by employing global quantum discord (GQD). We use the disorder-averaged GQD to estimate the MBL critical point, which is found to be around atWc=3.8by making a finite-size scaling analysis. We further compare our results of GQD with those of half-chain entanglement entropy (EE) that is promising in the study of MBL. We show that GQD can exclude the finite-size interference under the same condition, which implies that GQD is more robust than the half-chain EE in characterizing MBL.
作者机构：
[Wang, Xiaoqiang; Chen, Xuhao; Zhang, Juanjuan] Lanzhou Univ, Coll Civil Engn & Mech, Key Lab Mech Environm & Disaster Western China, Minist Educ China, Lanzhou 730000, Gansu, Peoples R China.;[Zhang, Juanjuan] Xi An Jiao Tong Univ, State Key Lab Strength & Vibrat Mech Struct, Xian 710049, Shanxi, Peoples R China.;[Fang, Chao] Wuhan Polytech Univ, Dept Elect & Elect Engn, Wuhan 430023, Hubei, Peoples R China.;[Weng, George J.] Rutgers State Univ, Dept Mech & Aerosp Engn, New Brunswick, NJ 08903 USA.
通讯机构：
[Juanjuan Zhang] K;[George J. Weng] D;Key Laboratory of Mechanics on Environment and Disaster in Western China, The Ministry of Education of China, College of Civil Engineering and Mechanics, Lanzhou University, Lanzhou, Gansu 730000, PR China<&wdkj&>State Key Laboratory for Strength and Vibration of Mechanical Structures, Xi’an Jiaotong University, Xi’an, Shanxi 710049, PR China<&wdkj&>Department of Mechanical and Aerospace Engineering, Rutgers University, New Brunswick, NJ 08903, USA
关键词：
0–3 polymer-based ME composites;Effective properties;Interphase effect;ME effect
摘要：
The advancement of Internet of Things technology has made continuous environmental monitoring a crucial re-quirement for various applications. To address the issue of the network life cycle, Wireless Rechargeable Sensor Networks (WRSNs) have emerged as a promising solution. This research is focused on WRSN applications in indoor settings such as the Industrial Internet of Things and indoor greenhouses. In such scenarios, rechargeable wireless sens-ing devices can gather the required information, reducing equipment costs and eliminating the inconvenience of wired sensors. This study proposes the utilization of a genetic al-gorithm to optimize the deployment of chargers in indoor environments. Compared to greedy algorithms, this approach can determine the best solution for charger deployment and minimize deployment expenses.
作者：
Du, Han;Zhang, Juanjuan;Fang, Chao;Weng, George J.
期刊：
Journal of Applied Polymer Science,2023年140(2):e53292- ISSN：0021-8995
通讯作者：
George J. Weng<&wdkj&>George J. Weng George J. Weng George J. Weng
作者机构：
[Weng, George J.; Du, Han] Rutgers State Univ, Dept Mech & Aerosp Engn, New Brunswick, NJ 08903 USA.;[Zhang, Juanjuan] Lanzhou Univ, Minist Educ China, Key Lab Mech Environm & Disaster Western China, Lanzhou, Peoples R China.;[Zhang, Juanjuan] Lanzhou Univ, Coll Civil Engn & Mech, Dept Mech & Engn Sci, Lanzhou, Peoples R China.;[Fang, Chao] Wuhan Polytech Univ, Dept Elect & Elect Engn, Wuhan, Peoples R China.
通讯机构：
[George J. Weng; George J. Weng George J. Weng George J. Weng] D;Department of Mechanical and Aerospace Engineering, Rutgers University, New Brunswick, New Jersey, USA
摘要：
Graphene agglomeration tends to develop with the increase of graphene loading. In this article, we present a unified model that first considers the evolution of graphene agglomeration and then incorporates it into the calculation of electrical and mechanical properties of agglomerated graphene/polymer nanocomposites. In the evolution of graphene agglomerates, a modified nanoparticle distance in terms of yield strength is introduced, while in the calculation of composite properties, a two-scale framework that consists of the graphene-rich agglomerates and the remainder as the graphene-poor region is constructed. In electrical conduction, electron tunneling is modeled through Simmons formula and its difference with the widely used Cauchy function is compared. We highlight that both Simmons and Cauchy functions could well describe the interfacial tunneling activity, but the former is physics-based while the latter is statistics-based. In the calculation of nonlinear elastoplastic response, a field-fluctuation method is adopted. We also demonstrated how the presented model gives rise to experimentally consistent electrical and mechanical properties of graphene/polypropylene nanocomposites, and how filler agglomeration hinders the performance of the materials.
通讯机构：
[Hu, K.] K;[Xiang, S.] S;Key Laboratory of Particle Physics and Particle Irradiation (MOE), Shandong, China;School of Electrical and Electronic Engineering, China
摘要：
Eutrophication is a severe worldwide concern caused by excessive phosphorus release. Thus, significant efforts have been made to develop phosphorus removal techniques, particularly by nanomaterial adsorption. However, because of the limitations associated with nanoparticles including easy agglomeration, and separation challenges, a novel nanocomposite adsorbent with great adsorption performance is urgently required. A sponge adsorbent (MS-CMC@La) was developed in this study to remove phosphorus using melamine sponge (MS), LaCl(3), and sodium carboxymethyl cellulose (CMC). The results of SEM/EDS, FTIR, and XPS demonstrated that La was well-dispersed on MS-CMC@La. Adsorption isotherm and kinetics met with the Langmuir model (R(2) = 0.981) and the pseudo-second-order kinetics (R(2) = 0.989), respectively. The maximum adsorption capacity of MS-CMC@La was found to be 15.28mg/g; the material exhibited excellent selectivity toward phosphorus in the presence of coexisting anion except of F(-); the adsorptionbehavior was greatly impacted by pH. Furthermore, the electrostatic attraction, ligand exchange and inner-sphere coordination regulate the phosphate adsorption mechanism, with inner-sphere coordination dominating. In summary, the nano-enriched materials developed in this study are capable of facilitating the application of functionalized sponges in the field of wastewater.
摘要：
Bulk Bi(0.5)Sr(0.5)Fe(0.5)Cr(0.5)O(3) (BSFCO) is a new compound comprising the R3c structure. The structural, magnetic property and exchange bias (EB) details are investigated. The material was in the super-paramagnetic (SP) state at room temperature. Exchange bias usually occurs at the boundary between different magnetic states after field cooling (H(FC)) acts on the sample. Here the result shows that changing H(FC) from 1 to 6T reduces the H(EB) value by 16% at 2K at the same time. Meanwhile, H(EB) diminishes as the ferromagnetic layer thickness increases. The variation of (the thickness of ferromagnetic layer) t(FM) with the change of H(FC) leads to the tuning of H(EB) by H(FC) in BSFCO bulk. These effects are obviously different from the phenomenon seen in other oxide types.
摘要：
Forward-looking sonar (FLS) images present various challenges in interpretation, recognition, and segmentation due to limitations like low resolution, speckle noise, and low contrast, making them more complex than optical images. Existing methods often focus solely on denoising or enhancement, neglecting the potential benefits of utilizing multi-scale features to create an integrated image processing approach. This paper introduces the Laplacian pyramid-based multi-scale denoising and enhancement (LPMsDE) method tailored for FLS images. The proposed method begins by presenting a novel multiplicative speckle noise model, grounded in the Gaussian distribution, specifically designed for FLS images. Next, the Laplacian pyramid decomposition is utilized to estimate noise variance, with an modified adaptive local filter. Lastly, a combination of the Laplacian pyramid framework, the enhanced adaptive local filter, and Contrast-Limited Histogram Equalization (CLHE) is employed to denoise and enhance images at different resolution levels. Through comprehensive experiments conducted on both simulated and real sonar images, the effectiveness of the LPMsDE method is demonstrated. It surpasses other denoising and enhancement techniques, as evidenced by superior scores in Structural Similarity Index (SSIM), Peak Signal-to-Noise Ratio (PSNR), Contrast-to-Noise Ratio (CNR), Equivalent Number of Looks (ENL), Natural Image Quality Evaluator (NIQE), and Blind/Referenceless Image Spatial Quality Evaluator (BRISQUE).
