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Design of a high sensitivity and wide range angular rate sensor based on exceptional surface

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Chinese Physics B 2024年第8期33卷 277-286页

作者：丁鑫圣刘文耀王师贤陶煜周彦汝白禹刘来邢恩博唐军刘俊 state key laboratory of dynamic measurement technology North University of ChinaTaiyuan 030051China Shanxi Province key laboratory of Quantum Sensing and Precision measurement North University of ChinaTaiyuan 030051China

It is found that when the parity–time symmetry phenomenon is introduced into the resonant optical gyro system and it works near the exceptional point,the sensitivity can in theory be significantly amplified at low angular ***,in fact,the exceptional point is easily disturbed by external environmental variables,which means that it depends on harsh experimental environment and strong control ability,so it is difficult to move towards practical ***,we propose a new angular rate sensor structure based on exceptional surface,which has the advantages of high sensitivity and high *** system consists of two fiber-optic ring resonators and two optical loop mirrors,and one of the resonators contains a variable ratio coupler and a variable optical *** theoretically analyze the system response,and the effects of phase and coupling ratio on the system ***,compared with the conventional resonant gyro,the sensitivity of this exceptional surface angular rate sensor can be improved by about 300 times at low *** addition,by changing the loss coefficient in the ring resonator,we can achieve a wide range of 600 rad/*** scheme provides a new approach for the development of ultra-high sensitivity and wide range angular rate sensors in the future.

关键词： exceptional surface exceptional points ring resonator angular rate sensing rotational direction recognition wide operating range PACS:42.81.Pa 42.81.Qb D0I:10.1088/1674-1056/ad4324

Langasite-based SAW high-temperature vibration sensor with temperature decoupling

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Science China(Technological Sciences) 2024年第6期67卷 1946-1956页

作者： ZHANG Juan CHENG WenHua WANG Hao ZHANG Lei LI XiangRong MA HongShuai PANG JunQi TAN QiuLin state key laboratory of dynamic measurement technology North University of ChinaTaiyuan030051China Department of Mechanical Engineering Taiyuan Institute of TechnologyTaiyuan030008China

Monitoring high-temperature vibrations is critical in aerospace engineering,industrial manufacturing,and energy production,where harsh conditions necessitate robust vibration sensors for detecting anomalous ***,the accuracy of such sensors is often compromised by crosstalk between temperature and vibration *** study introduces a high-temperature vibration sensor based on langasite(LGS)surface acoustic wave(SAW)technology,designed to withstand temperatures up to 500℃.The sensor demonstrates high sensitivity,ranging from 12.54 kHz/g at 25℃ to 15.63 k Hz/g at 500℃.A comprehensive mechanical and electrical coupling model for the SAW vibration sensor was developed by integrating theoretical equations with numerical simulations to optimize the sensor's ***,a novel decoupling algorithm for temperature and vibration was established,achieving thermomechanical decoupling with precise vibration *** results indicated a maximum relative deviation of 4.67%for the *** conclusion,the proposed LGS SAW vibration sensor emerges as a promising solution for the accurate detection of multiple parameters in high-temperature vibration monitoring.

关键词： high temperature langasite(LGS) surface acoustic wave(SAW) piezoelectric vibration sensor temperature decoupling

A highoutput PDMS-MXene/gelatin triboelectric nanogenerator with the petal surface-microstructure

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Nano Research 2024年第5期17卷 4151-4162页

作者： Zekun Wang Congcong Hao Mingzhe Cai Juan Cui Yongqiu Zheng Chenyang Xue key laboratory of Instrumentation Science&dynamic measurement Ministry of Education North University of ChinaTaiyuan 030051China state key laboratory of Electronic Thin Films and Integrated Devices University of Electronic Science and Technology of ChinaChengdu 611731China

Triboelectric nanogenerator(TENG)has a promising future in the field of energy harvesting and self-powered sensing due to their simplicity in structure,low cost,and efficient energy harvesting from the surrounding *** output electrical performance of TENG can be improved by doping the friction material with functional materials and modifying the surface of the friction ***,the current method of adding functional materials to friction materials is costly and wasteful,and the method of modifying the surface structure of friction materials is cumbersome and not easy to *** this work,we present a polydimethylsiloxane(PDMS)-MXene/gelatin triboelectric nanogenerator(PMMG-TENG)based on petal surface-microstructures,which has the advantages of low cost,simple preparation,high output performance,and ecological *** doping 0.03 wt.%of MXene in PDMS,the output electrical performance of TENG can be significantly improved,with an output current increase of up to 139.7%.Four different petals are used as natural molds to prepare *** results show that PMMG-TENG with peony petal surface microstructure has the best electrical performance,and the output current increase of up to 228.17%compared with PMMG-TENG without *** PMMG-TENG with peony petal surface-microstructure exhibits excellent electrical performance,demonstrating a maximum open-circuit voltage of 417.39 V and a maximum short-circuit current of 12.01μA at a size of 3 cm×3 cm,and a maximum power density of 170μW/cm^(2) at a load resistance of 107Ω.The PMMG-TENG’s output performance after 10,000 cycles is consistent with the initial state,highlighting excellent output *** PMMG-TENG can easily light up at least 100 light emitting diodes(LEDs).(operating voltage 3V.)Gelatin film exhibits excellent degradation performance,with complete degradation time of only 150 s in water at a constant temperature of 75℃.PMMG-TENG not only shows excellent performance in

关键词： triboelectric nanogenerator(TENG) petal surface-microstructure gelatin MXene energy harvesting

Wearable Leg Movement Monitoring System for High-Precision Real-Time Metabolic Energy Estimation and Motion Recognition

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Research 2024年第2期2023卷 417-429页

作者： Jinfeng Yuan Yuzhong Zhang Shiqiang Liu Rong Zhu state key laboratory of Precision measurement technology and Instruments Department of Precision InstrumentTsinghua UniversityBeijing 100084China

Comprehensive and quantitative assessment of human physical activity in daily life is valuable for healthcare,especially for those who suffer from obesity and neurological disorders or are at high risk of *** wearable devices,e.g.,smartwatches,are insufficient and inaccurate for monitoring highly dynamic limb movements and assessing human ***,we report a new wearable leg movement monitoring system incorporating a custom-made motion sensor with machine learning algorithm to perceive human motion accurately and comprehensively during diverse walking and running *** system enables real-time multimodal perceptions of personal identity,motion state,locomotion speed,and energy expenditure for wearers.A general law of extracting real-time metabolic energy from leg movements is verified although individual gaits show *** addition,we propose a novel sensing configuration combining unilateral lower leg movement velocity with its angular rate to achieve high accuracy and good generalizability while simplifying the wearable *** performances in personal identification(accuracy of 98.7%)and motion-state recognition(accuracy of 93.7%)are *** wearable system also exhibites high-precision real-time estimations of locomotion speed(error of 3.04%to 9.68%)and metabolic energy(error of 4.18%to 14.71%)for new subjects across various time-varying *** wearable system allows reliable leg movement monitoring and quantitative assessment of bodily kinematic and kinetic behaviors during daily activities,as well as safe identity authentication by gait parameters,which would greatly facilitate smart life,personal healthcare,and rehabilitation training.

关键词： smart enable monitoring

Electrostatic generator enhancements for powering IoT nodes via efficient energy management

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Microsystems & Nanoengineering 2024年第2期10卷 143-152页

作者： Zibo Wu Zeyuan Cao Junchi Teng Rong Ding Jiani Xu Xiongying Ye state key laboratory of Precision measurement technology and Instruments Department of Precision InstrumentTsinghua University100084BeijingChina

Electrostatic generators show great potential for powering widely distributed electronic devices in Internet of Things(IoT)***,a critical issue limiting such generators is their high impedance mismatch when coupled to electronics,which results in very low energy utilization ***,we present a high-performance energy management unit(EMU)based on a spark-switch tube and a buck converter with an RF *** optimizing the elements and parameters of the EMU,a maximum direct current output power of 79.2 mW m^(-2)rps^(-1)was reached for a rotary electret generator with the EMU,achieving 1.2 times greater power output than without the ***,the maximum power of the contact-separated triboelectric nanogenerator with an EMU is 1.5 times that without the *** excellent performance is attributed to the various optimizations,including utilizing an ultralow-loss spark-switch tube with a proper breakdown voltage,adding a matched input capacitor to enhance available charge,and incorporating an RF inductor to facilitate the high-speed energy transfer *** on this extremely efficient EMU,a compact self-powered wireless temperature sensor node was demonstrated to acquire and transmit data every 3.5 s under a slight wind speed of 0.5 m/*** work greatly promotes the utilization of electrostatic nanogenerators in practical applications,particularly in IoT nodes.

关键词： IoT power generator

Metasurface array for single-shot spectroscopic ellipsometry

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Light(Science & Applications) 2024年第5期13卷 835-842页

作者： Shun Wen Xinyuan Xue Shuai Wang Yibo Ni Liqun Sun Yuanmu Yang Department of Precision Instrument State Key Laboratory of Precision Measurement Technology and InstrumentsTsinghua UniversityBeijing 100084China

Spectroscopic ellipsometry is a potent method that is widely adopted for the measurement of thin film thickness and refractive *** conventional ellipsometers utilize mechanically rotating polarizers and grating-based spectrometers for spectropolarimetric ***,we demonstrated a compact metasurface array-based spectroscopic ellipsometry system that allows single-shot spectropolarimetric detection and accurate determination of thin film properties without any mechanical *** silicon-based metasurface array with a highly anisotropic and diverse spectral response is combined with iterative optimization to reconstruct the full Stokes polarization spectrum of the light reflected by the thin film with high ***,the film thickness and refractive index can be determined by fitting the measurement results to a proper material model with high *** approach opens up a new pathway towards a compact and robust spectroscopic ellipsometry system for the high throughput measurement of thin film properties.

关键词： properties. spectroscopic film

Multi-circular formation control with reinforced transient profiles for nonholonomic vehicles:A path-following framework

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Defence technology（防务技术） 2024年第1期31卷 278-287页

作者： Jintao Zhang Xingling Shao Wendong Zhang Zongyu Zuo School of Instrument and Electronics North University of ChinaTaiyuan 030051China state key laboratory of dynamic measurement technology North University of ChinaTaiyuan 030051China Seventh Research Division School of Automation Science and Electrical EngineeringBeihang UniversityBeijing 100191China

This article investigates a multi-circular path-following formation control with reinforced transient profiles for nonholonomic vehicles connected by a digraph.A multi-circular formation controller endowed with the feature of spatial-temporal decoupling is devised for a group of vehicles guided by a virtual leader evolving along an implicit path,which allows for a circumnavigation on multiple circles with an anticipant angular *** addition,notice that it typically imposes a stringent time constraint on time-sensitive enclosing scenarios,hence an improved prescribed performance control(IPPC)using novel tighter behavior boundaries is presented to enhance transient capabilities with an ensured appointed-time convergence free from any *** significant merits are that coordinated circumnavigation along different circles can be realized via executing geometric and dynamic assignments independently with modified transient ***,all variables existing in the entire system are analyzed to be *** and experimental results are provided to validate the utility of suggested solution.

关键词： Multi-circular formation Reinforced transient profiles Nonholonomic vehicles Path following

Ultrafast optical investigation of carrier and spin dynamics in low-dimensional perovskites

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Science China(Technological Sciences) 2024年第1期67卷 2-18页

作者： FU JinYue JIANG Ying FANG HongHua key laboratory for Micro-Nano Physics and technology of Hunan Province School of Physics and ElectronicsHunan UniversityChangsha 410012China state key laboratory of Precision measurement technology and Instruments Department of Precision InstrumentTsinghua UniversityBeijing 100084China

Low-dimensional perovskite(PVK)materials have attracted significant research interest,because of their quantum-confined effect,tunable band gap structures,and higher stability than that of three-dimensional(3D)*** semiconductor optoelectronic devices,high speed and small size are closely *** development of high-speed devices requires researchers to fully understand the properties of materials,especially the dynamic processes such as carrier recombination,separation,and transport,which often play a crucial role in the performance of *** an indispensable part of dynamic research,spin relaxation is also of great significance in studying the properties of materials and explore possible *** halide PVK materials have strong spin-orbit coupling(SOC),which provides a basis for information storage and processing by using spin degrees of ***,studying the carrier and spin dynamics of low-dimensional PVKs is an effective way to understand the internal properties of low-dimensional PVKs *** paper summarizes the latest research progress on the ultrafast carrier and spin dynamics in low-dimensional PVKs,to comprehensively understand their carrier and spin behaviors and present an outlook for relevant studies in this area.

关键词： low-dimensional perovskites carrier dynamics spin dynamics optoelectronic devices

Laser manufacturing of spatial resolution approaching quantum limit

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Light(Science & Applications) 2024年第3期13卷 421-428页

作者： Xiao-Jie Wang Hong-Hua Fang Zhen-Ze Li Dan Wang Hong-Bo Sun state key laboratory of Precision measurement technology and Instruments Department of Precision InstrumentTsinghua UniversityBeijing 100084China state key laboratory of Integrated Optoelectronics College of Electronic Science and EngineeringJilin University2699 Qianjin StreetChangchun 130012China

Atomic and close-to-atom scale manufacturing is a promising avenue toward single-photon emitters,single-electron transistors,single-atom memory,and quantum-bit devices for future communication,computation,and sensing *** manufacturing is outstanding to this end for ease of beam manipulation,batch production,and no requirement for *** is,however,suffering from optical diffraction ***,we report a spatial resolution improved to the quantum limit by exploiting a threshold tracing and lock-in method,whereby the two-order gap between atomic point defect complexes and optical diffraction limit is surpassed,and a feature size of<5 nm is *** underlying physics is that the uncertainty of local atom thermal motion dominates electron excitation,rather than the power density slope of the incident *** show that the colour centre yield in hexagonal boron nitride is transformed from stochastic to deterministic,and the emission from individual sites becomes polychromatic to *** a result,single colour centres in the regular array are deterministically created with a unity yield and high positional accuracy,serving as a step forward for integrated quantum technological applications.

关键词： quantum limit resolution