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Design of tightly linked dual ring antenna and imaging of magnetic field distribution using a diamond fiber probe

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Chinese Physics B 2024年第2期33卷 347-352页

作者：叶青云薛雅文何飞越赵旭彤卞雨辰卢文韬王金旭陈鸿浩夏圣开曾明菁杜关祥 College of Telecommunications and Information Engineering Nanjing University of Posts and TelecommunicationsNanjing 210003China College of Science Nanjing University of Posts and TelecommunicationsNanjing 210003China school of Computer Science Nanjing University of Posts and TelecommunicationsNanjing 210023China Bell honors school Nanjing University of Posts and TelecommunicationsNanjing 210023China

A tightly linked dual ring antenna is designed,and it is specifically tailored for uniformly coupling the microwave magnetic field to the nitrogen-vacancy(NV)center.The designed antenna operates at a center frequency of about 2.87 GHz,with a bandwidth of around 200 MHz,allowing it to address multiple resonance peaks in the optically detected magnetic resonance(ODMR)spectrum in an external magnetic field.Moreover,the antenna generates a fairly uniform magnetic field in a range with a radius of 0.75 mm.High resolution imaging of the magnetic field distribution on the surface of the antenna is conducted by using a fiber diamond probe.We also investigate the effect of magnetic field uniformity on the linewidth of ODMR,so as to provide insights into reducing the inhomogeneous broadening of ODMR.

关键词： nitrogen vacancy(NV) microwave(MW)imaging inhomogeneous broadening

High-resolution imaging of magnetic fields of banknote anti-counterfeiting strip using fiber diamond probe

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Chinese Physics B 2024年第4期33卷 720-727页

作者：赵旭彤何飞越薛雅文马文豪殷筱晗夏圣开曾明菁杜关祥 College of Telecommunications and Information Engineering Nanjing University of Posts and TelecommunicationsNanjing 210003China College of Science Nanjing University of Posts and TelecommunicationsNanjing 210003China school of Computer Science Nanjing University of Posts and TelecommunicationsNanjing 210023China Bell honors school Nanjing University of Posts and TelecommunicationsNanjing 210023China

Counterfeiting of modern banknotes poses a significant challenge,prompting the use of various preventive measures.One such measure is the magnetic anti-counterfeiting strip.However,due to its inherent weak magnetic properties,visualizing its magnetic distribution has been a longstanding challenge.In this work,we introduce an innovative method by using a fiber optic diamond probe,a highly sensitive quantum sensor designed specifically for detecting extremely weak magnetic fields.We employ this probe to achieve high-resolution imaging of the magnetic fields associated with the RMB 50denomination anti-counterfeiting strip.Additionally,we conduct computer simulations by using COMSOL Multiphysics software to deduce the potential geometric characteristics and material composition of the magnetic region within the anti-counterfeiting strip.The findings and method presented in this study hold broader significance,extending the RMB 50 denomination to various denominations of the Chinese currency and other items that employ magnetic anti-counterfeiting strips.These advances have the potential to significantly improve and promote security measures in order to prevent the banknotes from being counterfeited.

关键词： banknote anti-counterfeiting strip nitrogen-vacancy(NV)centers magnetic field imaging numerical simulation

Electrical uniformity analyses on 12-inch Si-based Hf0.5Zr0.5O2 ferroelectric capacitor devices by atomic layer deposition

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Progress in Natural Science:Materials International 2024年第3期34卷 598-605页

作者： Wen-Juan Ding Yu Liu Zhi-Qiang Xiao Li Gao Yu-Chen Li Lin Zhu Xiang Li Wei-Min Li Shuang Chen Ai-Dong Li National Laboratory of Solid State Microstructures College of Engineering and Applied Sciences and Collaborative Innovation Center of Advanced MicrostructuresNanjing University Jiangsu Leadmicro Nano-Technology Co. Ltd. Semiconductor Manufacturing North China Corp. Kuang Yaming honors school Nanjing University

The study on the uniformity of electrical performance of large wafer-scale Hf0.5Zr0.5O2（HZO） ferroelectric capacitors is still lacking yet now. In this work, TiN/HZO/TiN metal-ferroelectric-metal（MFM） devices on 12-inch silicon wafers have been fabricated by thermal atomic layer deposition. The correlation of thickness uniformity with device-to-device variation of electrical properties and yield of the 12-inch MFM system was investigated. It was found that the uniformity of ferroelectric properties is closely related to the variation of HZO thickness of the MFM system, the concentration of oxygen vacancies in the micro-region of the HZO film, and the ferroelectric phase micro-distribution on 12-inch Si wafer. This work provides some important information for the performance optimization of HfO2-based ferroelectric random access memories.

关键词： 12-Inch Si wafer Atomic layer deposition Electrical uniformity Ferroelectric random access memory Hf0.5Zr0.5O2 ferroelectric thin film

Monocular Distance Estimated Based on PTZ Camera

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Computers, Materials & Continua 2024年第5期79卷 3417-3433页

作者： Qirui Zhong Xiaogang Cheng Yuxin Song Han Wang Bell honors school Nanjing University of Posts and Telecommunications Nanjing210003China College of Telecommunications and Information Engineering Nanjing University of Posts and TelecommunicationsNanjing210003China College of Automation and College of Artificial Intelligence Nanjing University of Posts and TelecommunicationsNanjing210003China

This paper introduces an intelligent computational approach for extracting salient objects fromimages and estimatingtheir distance information with PTZ (Pan-Tilt-Zoom) cameras. PTZ cameras have found wide applications innumerous public places, serving various purposes such as public securitymanagement, natural disastermonitoring,and crisis alarms, particularly with the rapid development of Artificial Intelligence and global infrastructuralprojects. In this paper, we combine Gauss optical principles with the PTZ camera’s capabilities of horizontal andpitch rotation, as well as optical zoom, to estimate the distance of the object.We present a novel monocular objectdistance estimation model based on the Focal Length-Target Pixel Size (FLTPS) relationship, achieving an accuracyrate of over 95% for objects within a 5 km range. The salient object extraction is achieved through a simplifiedconvolution kernel and the utilization of the object’s RGB features, which offer significantly faster computingspeeds compared to Convolutional Neural Networks (CNNs). Additionally, we introduce the dark channel beforethe fog removal algorithm, resulting in a 20 dB increase in image definition, which significantly benefits distanceestimation. Our system offers the advantages of stability and low device load, making it an asset for public securityaffairs and providing a reference point for future developments in surveillance hardware.

关键词： Public security location information PTZ camera image processing

Trusted detection for Parkinson’s disease based on uncertainty estimation

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The Journal of China Universities of Posts and Telecommunications 2024年

作者： Zhou Lin Li Yun Ji Wei Liu Yuxuan Zheng Huifen school of Computer Science Nanjing University of Posts and Telecommunications school of Communications and Information Engineering Nanjing University of Posts and Telecommunications Bell honors school Nanjing University of Posts and Telecommunications Affiliated Geriatric Hospital of Nanjing Medical University

Currently， most deep learning methods used for Parkinson’s disease (PD) detection lack reliability assessment. This characteristic makes erroneous results difficult to be identified in practice， leading to potentially serious consequences. To address this issue， prior network with the distance measure layer (PNDM) was proposed in this paper. PNDM consists of two modules: prior network (PN) and the distance measure (DM) layer. The prior network is employed to estimate data uncertainty， and the DM layer is utilized to estimate model uncertainty. The goal of this work is to provide accurate and reliable PD detection through uncertainty estimation. Experiments show that PNDM can effectively estimate both model uncertainty and data uncertainty， rendering it more suitable for uncertainty estimation in PD detection compared to existing methods.

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Individual dynamics and local heterogeneity provide a microscopic view of the epidemic spreading

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Chinese Physics B 2024年第5期33卷 656-663页

作者：朱友源沈瑞哲董昊王炜 Kuang Yaming honors school Nanjing UniversityNanjing 210023China Collaborative Innovation Center of Advanced Microstructures National Laboratory of Solid State MicrostructureSchool of PhysicsNanjing UniversityNanjing 210093China Institute for Brain Sciences Nanjing UniversityNanjing 210023China State Key Laboratory of Analytical Chemistry for Life Science Nanjing UniversityNanjing 210023China

The COVID-19 pandemic has caused severe global disasters,highlighting the importance of understanding the details and trends of epidemic transmission in order to introduce efficient intervention measures.While the widely used deterministic compartmental models have qualitatively presented continuous “analytical” insight and captured some transmission features,their treatment usually lacks spatiotemporal variation.Here,we propose a stochastic individual dynamical(SID)model to mimic the random and heterogeneous nature of epidemic propagation.The SID model provides a unifying framework for representing the spatiotemporal variations of epidemic development by tracking the movements of each individual.Using this model,we reproduce the infection curves for COVID-19 cases in different areas globally and find the local dynamics and heterogeneity at the individual level that affect the disease outbreak.The macroscopic trend of virus spreading is clearly illustrated from the microscopic perspective,enabling a quantitative assessment of different interventions.Seemingly,this model is also applicable to studying stochastic processes at the “meter scale”,e.g.,human society’s collective dynamics.

关键词： Brownian motion epidemic spreading heterogeneity

Collision off-axis position dependence of relativistic nonlinear Thomson inverse scattering of an excited electron in a tightly focused circular polarized laser pulse

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Chinese Physics B 2024年第1期33卷 344-354页

作者：王禹博杨青屿常一凡林宗熠田友伟 Bell honors school Nanjing University of Posts and TelecommunicationsNanjing 210023China College of Science Nanjing University of Posts and TelecommunicationsNanjing 210023China

This paper presents a novel view of the impact of electron collision off-axis positions on the dynamic properties and relativistic nonlinear Thomson inverse scattering of excited electrons within tightly focused, circularly polarized laser pulses of varying intensities. We examine the effects of the transverse ponderomotive force, specifically how the deviation angle and speed of electron motion are affected by the initial off-axis position of the electron and the peak amplitude of the laser pulse. When the laser pulse intensity is low, an increase in the electron's initial off-axis distance results in reduced spatial radiation power, improved collimation, super-continuum phenomena generation, red-shifting of the spectrum's harmonic peak, and significant symmetry in the radiation radial direction. However, in contradiction to conventional understandings,when the laser pulse intensity is relatively high, the properties of the relativistic nonlinear Thomson inverse scattering of the electron deviate from the central axis, changing direction in opposition to the aforementioned effects. After reaching a peak, these properties then shift again, aligning with the previous direction. The complex interplay of these effects suggests a greater nuance and intricacy in the relationship between laser pulse intensity, electron position, and scattering properties than previously thought.

关键词： relativistic nonlinear Thomson inverse scattering off-axis collision radiation angle distribution tightly focused laser pulse

Tunable dispersion relations manipulated by strain in skyrmion-based magnonic crystals

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Chinese Physics B 2024年第1期33卷 692-696页

作者：金兆年何宣霖于超方贺男陈琳陶志阔 Bell honors school Nanjing University of Posts and TelecommunicationsNanjing 210003China College of Electronic and Optical Engineering&College of Flexible Electronics Nanjing University of Posts and TelecommunicationsNanjing 210003China

We theoretically investigate the propagation characteristics of spin waves in skyrmion-based magnonic crystals. It is found that the dispersion relation can be manipulated by strains through magneto-elastic coupling. Especially, the allowed bands and forbidden bands in dispersion relations shift to higher frequency with strain changing from compressive to tensile,while shifting to lower frequency with strain changing from tensile to compressive. We also confirm that the spin wave with specific frequency can pass the magnonic crystal or be blocked by tuning the strains. The result provides an advanced platform for studying the tunable skyrmion-based spin wave devices.

关键词： skyrmion magnonic crystal spin wave dispersion relation

A General Framework for Intelligent IoT Data Acquisition and Sharing in an Untrusted Environment Based on Blockchain

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China Communications 2024年第3期21卷 137-148页

作者： Lu Yin Xue Yongtao Li Qingyuan Wu Luocheng Li Taosen Yang Peipei Zhu Hongbo College of Internet of Things Nanjing University of Posts and TelecommunicationsNanjing 210003China Key Lab of Broadband Wireless Communication and Sensor Network Technology(Nanjing University of Posts and Telecommunications) Ministry of EducationNanjing 210003China Jiangsu Key Laboratory of Wireless Communications Nanjing University of Posts and TelecommunicationsNanjing 210003China Research Institute of Internet of Things Nanjing University of Posts and TelecommunicationsNanjing 210003China Bell honors school Nanjing University of Posts and TelecommunicationsNanjing 210023China school of Automation Nanjing University of Posts and TelecommunicationsNanjing 210023China

Traditional Io T systems suffer from high equipment management costs and difficulty in trustworthy data sharing caused by centralization.Blockchain provides a feasible research direction to solve these problems. The main challenge at this stage is to integrate the blockchain from the resourceconstrained Io T devices and ensure the data of Io T system is credible. We provide a general framework for intelligent Io T data acquisition and sharing in an untrusted environment based on the blockchain, where gateways become Oracles. A distributed Oracle network based on Byzantine Fault Tolerant algorithm is used to provide trusted data for the blockchain to make intelligent Io T data trustworthy. An aggregation contract is deployed to collect data from various Oracle and share the credible data to all on-chain users. We also propose a gateway data aggregation scheme based on the REST API event publishing/subscribing mechanism which uses SQL to achieve flexible data aggregation. The experimental results show that the proposed scheme can alleviate the problem of limited performance of Io T equipment, make data reliable, and meet the diverse data needs on the chain.

关键词： blockchain data sharing Internet of Things Oracle