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The Role of Permanent and Induced Electrostatic Dipole Moments for Schottky Barriersin Janus MXY/Graphene Heterostructures: A First Principles Study

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arXiv 2022年

作者： Chen, Yu-Qi Zhang, Huan-Huan Wen, Bo Li, Xi-Bo Chai, Yi-Feng Xu, Ying Wei, Xiao-Lin Yin, Wen-Jin Teobaldi, Gilberto School of Physics and Electronic Science Hunan University of Science and Technology Xiangtan411201 China Key Laboratory of Intelligent Sensors and Advanced Sensing Materials of Hunan Province Hunan University of Science and Technology Xiangtan411201 China School of Physics and Electronics Henan University Kaifeng475001 China Department of Physics Jinan University Guangzhou510632 China Department of Physics Laboratory for Quantum Engineering and Micro-Nano Energy Technology Xiangtan University Hunan Xiangtan411105 China Scientific Computing Department STFC UKRI Rutherford Appleton Laboratory Harwell Campus DidcotOX11 0QX United Kingdom School of Chemistry University of Southampton High Field Southampton SO17 1BJ United Kingdom

The Schottky barrier height (ESBH) is a crucialfactorin determining the transport properties of semiconductor materials as it directly regulatesthe carrier mobility in opto-electronics *** principle, van der Waals (vdW)Janusheterostructures offer an appealing avenue to controlling the ***, the underlying atomistic mechanismsare far from understood conclusively, which prompts for further research in the topic. To this end,here, we carryout an extensive first principles study of the electronic properties and ESHBof several vdW Janus MXY/Graphene(M=Mo, W;X, Y=S, Se, Te) *** results of the simulations show that by changing the composition and geometry of the heterostructure's interface, it is possible to controlitselectrical contact, thence electron transport properties, from Ohmicto Schottky with nearly one order of magnitude variationsin the *** analysis of the simulations enables rationalization of this highly attractive propertyon the basis of theinterplaybetween the permanent dipole moment of the Janus MXYsheet and the induced one due to interfacial charge redistribution at the MXY/Grinterface. Such an interplayis shown to be highly effectivein alteringthe electrostatic potential difference acrossthe vdW Janus heterostructure, determining its ESBH, thence Schottky (Ohmic) contact type. These computational findings contribute guidelines to control electrical contactsinJanus heterostructurestowardsrationaldesign of electrical contacts in nanoscale devices. © 2022, CC BY.

关键词： Van der Waals forces

Formation of singularity for the rotating shallow water system

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arXiv 2020年

作者： Huang, Yupei Chunjing, X.I.E. Department of mathematics Duke University United States School of mathematical Sciences Institute of Natural Sciences Ministry of Education Key Laboratory of Scientific and Engineering Computing SHL-MAC Shanghai Jiao Tong Vniversity 800 Dongchuan Road Shanghai China

In this paper, we investigate the formation of singularity for general two dimensional and radially symmetric solutions for rotating shallow water system from different aspects. First, the formation of singularity is proved via the study for the associated moments for two dimensional solutions. For the radial symmetric solutions, the formation of singularity is established for the initial data with compact support. Finally, the global existence or formation of singularity for the radial symmetric solutions of the rotating shallow water system are analyzed in detail when the solutions are of the form with separated variables. Copyright © 2020, The Authors. All rights reserved.

关键词： Waterworks

Magnetization of Co-Fe-Ta-B-O Amorphous Thin Films

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Chinese Physics Letters 2019年第7期36卷 103-106页

作者： Chengyue Xiong Cheng Chen Wen Sun Ziyao Lu Hongming Mou Xiaozhong Zhang Key Laboratory of Advanced Materials (MOE) School of Materials Science and Engineering Tsinghua University Beijing 100084 Beijing National Center for Electron Microscopy Tsinghua University Beijing 100084 Centre for Brain-Inspired Computing Researchy Tsinghua University Beijing 100084 Research Institute for Magnetoelectronics & Weak Magnetic-field Detection College of Science China Three Gorges of University Yichang 443002 Institute of Microelectronics Tsinghua University Beijing 100084

An amorphous magnetic material system(Co20Fe47Ta20B13)1-xOx is fabricated by magneto sputtering. Three stages of magnetization behavior exist when oxygen content changes in the system. As the oxygen increases, the absence of percolation effect of magnetic nano-particles makes the multi-domain structure broken so that high coercivity appears in the samples with proper oxygen content. A temperature-dependent Stoner–Wohlfarth model is used to explain the magnetization properties at relatively high temperature. Magnetizations with magnetic field in and out of the sample plane are also investigated to prove the mechanisms. This work provides a systematic study of a new kind ofv amorphous magnetic system and is helpful for us to know more about this type of material.

关键词： An amorphous magnetic fabricated by magneto this type of material

Selective excitation of a three-dimensionally oriented single plasmonic dipole

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Photonics Research 2019年第6期7卷 693-698页

作者： FAJUN XIAO GUANGLIN WANG XUETAO GAN WUYUN SHANG SHIYIN CAO WEIREN ZHU TING MEI MALIN PREMARATNE JIANLIN ZHAO MOE Key Laboratory of Material Physics and Chemistry under Extraordinary Conditions and Shaanxi Key Laboratory of Optical Information Technology School of Science Northwestern Polytechnical University Xi'an 710129 China Department of Electronic Engineering Shanghai Jiao Tong University Shanghai 200240 China Advanced Computing and Simulation Laboratory (AXL) Department of Electrical and Computer Systems Engineering Monash University Clayton VIC 3800 Australia

We experimentally demonstrate a scheme to deterministically excite a three-dimensionally oriented electric dipole in a single Au nanosphere by using a tightly focused radially polarized beam whose focal field possesses polarization states along three-dimensional(3D) orientations owing to the spatial overlap between longitudinal and radial electric field components. Experiment observations indicate that the orientation of an excited dipole moment gradually changes from out-of-plane to in-plane when the nanosphere is moved away from the beam center, which is reconfirmed by full-wave simulations. Moreover, rigorous calculation based on Mie theory reveals that a reduced effective ambient permittivity accompanies the rotation of the dipole moment, leading to a blue-shifted and narrowed resonance peak. We envision that our results could find applications in detecting the 3D orientation of isolated molecules and benefit the fine manipulation of light–matter interactions at the single-molecule level.

关键词： Selective excitation plasmonic dipole

Unconditionally optimal convergence of an energy-conserving and linearly implicit scheme for nonlinear wave equations

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arXiv 2021年

作者： Cao, Waixiang Li, Dongfang Zhang, Zhimin School of Mathematical Sciences Beijing Normal University Beijing100875 China School of Mathematics and Statistics Huazhong University of Science and Technology Wuhan430074 China Hubei Key Laboratory of Engineering Modeling and Scientific Computing Huazhong University of Science and Technology Wuhan430074 China Beijing Computational Science Research Center Beijing100193 China Department of Mathematics Wayne State University DetroitMI48202 United States

In this paper, we present and analyze an energy-conserving and linearly implicit scheme for solving the nonlinear wave equations. Optimal error estimates in time and superconvergent error estimates in space are established without time-step dependent on the spatial mesh size. The key is to estimate directly the solution bounds in the H2-norm for both the nonlinear wave equation and the corresponding fully discrete scheme, while the previous investigations rely on the temporal-spatial error splitting approach. Numerical examples are presented to confirm energy-conserving properties, unconditional convergence, and optimal error estimates, respectively, of the proposed fully discrete *** Codes 65M60, 65M12, 65N12 © 2021, CC0.

关键词： Wave equations

A logical approach for the schedulability analysis of CCSL 13

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A logical approach for the schedulability analysis of CCSL

13th International Symposium on Theoretical Aspects of Software engineering, TASE 2019

作者： Zhang, Yuanrui Mallet, Frederic Zhu, Huibiao Chen, Yixiang MoE Engineering Research Center for Software/Hardware Co-design East China Normal University China I3S Laboratory UMR 7271 CNRS INRIA Université Nice Sophia Antipolis France Shanghai Key Laboratory of Trustworthy Computing East China Normal University China

ISBN: (纸本)9781728133423

The Clock Constraint Specification Language (CCSL) is a clock-based formalism for formal specification and analysis of real-time embedded systems. Previous approaches for the schedulability analysis of CCSL specifications are mainly based on model checking or SMT-checking. In this paper we propose a logical approach mainly based on theorem proving. We build a dynamic logic called 'clock-based dynamic logic' (cDL) to capture the CCSL specifications and build a proof calculus to analyze the schedule problem of the specifications. Comparing with previous approaches, our method benefits from the dynamic logic that provides a natural way of capturing the dynamic behaviour of CCSL and a divide-and-conquer way for 'decomposing' a complex formula into simple ones for an SMT-checking procedure. Based on cDL, we outline a method for the schedulability analysis of CCSL. We illustrate our theory through one example. © 2019 IEEE.

关键词： Clocks

High order asymptotic preserving Hermite WENO fast sweeping method for the steady-state SN transport equation

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arXiv 2021年

作者： Ren, Yupeng Xing, Yulong Wang, Dean Qiu, Jianxian School of Mathematical Sciences Xiamen University XiamenFujian361005 China Department of Mathematics Ohio State University ColumbusOH43210 United States Department of Mechanical and Aerospace Engineering Ohio State University ColumbusOH43210 United States School of Mathematical Sciences Fujian Provincial Key Laboratory of Mathematical Modeling and High-Performance Scientific Computing Xiamen University XiamenFujian361005 China

In this paper, we propose to combine the fifth order Hermite weighted essentially non-oscillatory (HWENO) scheme and fast sweeping method (FSM) for the solution of the steady-state SN transport equation in the finite volume framework. It is well-known that the SN transport equation asymptotically converges to a macroscopic diffusion equation in the limit of optically thick systems with small absorption and sources. Numerical methods which can preserve the asymptotic limit are referred to as asymptotic preserving methods. In the one-dimensional case, we provide the analysis to demonstrate the asymptotic preserving property of the high order finite volume HWENO method, by showing that its cell-edge and cell-average fluxes possess the thick diffusion limit. Numerical results in both one- and two- dimensions are presented to validate its asymptotic preserving property. A hybrid strategy to compute the nonlinear weights in the HWENO reconstruction is introduced to save computational cost. Extensive one- and two-dimensional numerical experiments are performed to verify the accuracy, asymptotic preserving property and positivity of the proposed HWENO FSM. Copyright © 2021, The Authors. All rights reserved.

关键词： Diffusion

The role of slow manifolds in parameter estimation for a multiscale stochastic system with α-stable Lévy noise

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arXiv 2020年

作者： Chao, Ying Wei, Pingyuan Duan, Jinqiao School of Mathematics and Statistics Center for Mathematical Sciences Hubei Key Laboratory for Engineering Modeling and Scientific Computing Huazhong University of Science and Technology Wuhan430074 China Department of Applied Mathematics Illinois Institute of Technology ChicagoIL60616 United States

This work is about parameter estimation for a fast-slow stochastic system with non-Gaussian α-stable Lévy noise. When the observations are only available for slow components, a system parameter is estimated and the accuracy for this estimation is quantified by p-moment with p ∈ (1, α), with the help of a reduced system through random slow manifold approximation. This method provides an advantage in computational complexity and cost, due to the dimension reduction in stochastic systems. To numerically illustrate this method, and to corroborate that the parameter estimator based on the reduced slow system is a good approximation for the true parameter value of the original system, a prototypical example is present. Copyright © 2020, The Authors. All rights reserved.

关键词： Parameter estimation

Non-invasive biopsy diagnosis of diabetic kidney disease via deep learning applied to retinal images: a population-based study

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The Lancet Digital Health 2025年第5期7卷 100868页

作者： Meng, Ziyao Guan, Zhouyu Yu, Shujie Wu, Yilan Zhao, Yaoning Shen, Jie Lim, Cynthia Ciwei Chen, Tingli Yang, Dawei Ran, An Ran He, Feng Hamzah, Haslina Singh, Sarkaaj Abd Raof, Anis Syazwani Lee-Boey, Jian Wen Samuel Lim, Soo-Kun Sun, Xufang Ge, Shuwang Xu, Gang Su, Hua Cheng, Yang Lu, Feng Liao, Xiaofei Jin, Hai Deng, Chenxin Ruan, Lei Zhang, Cuntai Wu, Chan Dai, Rongping Jin, Yixiao Wang, Wenxiao Li, Tingyao Liu, Ruhan Li, Jiajia Shu, Jia Lu, Yuwei Wang, Xiangning Wu, Qiang Qin, Yiming Tang, Jin Sheng, Xiaohua Jiao, Qiong Yang, Xiaokang Guo, Minyi McKay, Gareth J Hogg, Ruth E Liew, Gerald Chee, Evelyn Yi Lyn Hsu, Wynne Lee, Mong Li Szeto, Simon Luk, Andrea O Y Chan, Juliana C N Cheung, Carol Y Tan, Gavin Siew Wei Tham, Yih-Chung Cheng, Ching-Yu Sabanayagam, Charumathi Lim, Lee-Ling Jia, Weiping Li, Huating Sheng, Bin Wong, Tien Yin Shanghai Belt and Road International Joint Laboratory of Intelligent Prevention and Treatment for Metabolic Diseases Department of Computer Science and Engineering School of Electronic Information and Electrical Engineering Institute for Proactive Healthcare Shanghai Jiao Tong University Department of Endocrinology and Metabolism Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine Shanghai Diabetes Institute Shanghai Clinical Centre for Diabetes Shanghai Key Laboratory of Diabetes Mellitus Shanghai China MOE Key Laboratory of AI School of Electronic Information and Electrical Engineering Shanghai Jiao Tong University Shanghai China Beijing Tsinghua Changgung Hospital Eye Center School of Clinical Medicine Tsinghua Medicine Tsinghua University Beijing China Medical Records and Statistics Office Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine Shanghai China Department of Renal Medicine Singapore General Hospital SingHealth-Duke Academic Medical Centre Singapore Singapore Department of Ophthalmology Shanghai Health and Medical Center Wuxi China Department of Ophthalmology and Visual Sciences The Chinese University of Hong Kong Hong Kong Special Administrative Region China Singapore Eye Research Institute Singapore National Eye Centre Singapore Department of Medicine Faculty of Medicine Universiti Malaya Kuala Lumpur Malaysia Department of Ophthalmology Tongji Hospital Tongji Medical College Huazhong University of Science and Technology Hubei Wuhan China Department of Nephrology Tongji Hospital Tongji Medical College Huazhong University of Science and Technology Wuhan China Department of Nephrology Union Hospital Tongji Medical College Huazhong University of Science and Technology Wuhan China Department of Ophthalmology Union Hospital Tongji Medical College Huazhong University of Science and Technology Wuhan China National Engineering Research Centre for Big Dat

Background: Improving the accessibility of screening diabetic kidney disease (DKD) and differentiating isolated diabetic nephropathy from non-diabetic kidney disease (NDKD) are two major challenges in the field of diabetes care. We aimed to develop and validate an artificial intelligence (AI) deep learning system to detect DKD and isolated diabetic nephropathy from retinal fundus images. Methods: In this population-based study, we developed a retinal image-based AI-deep learning system, DeepDKD, pretrained using 734 084 retinal fundus images. First, for DKD detection, we used 486 312 retinal images from 121 578 participants in the Shanghai Integrated Diabetes Prevention and Care System for development and internal validation, and ten multi-ethnic datasets from China, Singapore, Malaysia, Australia, and the UK (65 406 participants) for external validation. Second, to differentiate isolated diabetic nephropathy from NDKD, we used 1068 retinal images from 267 participants for development and internal validation, and three multi-ethnic datasets from China, Malaysia, and the UK (244 participants) for external validation. Finally, we conducted two proof-of-concept studies: a prospective real-world study with 3 months' follow-up to evaluate the effectiveness of DeepDKD in screening DKD;and a longitudinal analysis of the effectiveness of DeepDKD in differentiating isolated diabetic nephropathy from NDKD on renal function changes with 4·6 years' follow-up. Findings: For detecting DKD, DeepDKD achieved an area under the receiver operating characteristic curve (AUC) of 0·842 (95% CI 0·838–0·846) on the internal validation dataset and AUCs of 0·791–0·826 across external validation datasets. For differentiating isolated diabetic nephropathy from NDKD, DeepDKD achieved an AUC of 0·906 (0·825–0·966) on the internal validation dataset and AUCs of 0·733–0·844 across external validation datasets. In the prospective study, compared with the metadata model, DeepDKD could detect DKD wit

关键词： Deep learning