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High Sensitivity Submicron Scale Temperature Sensor Based on Perovskite Nanoplatelet Lasers

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SSRN 2024年

作者： Zhao, Ruofan Tao, Jianxun Xi, Yuying Chen, Jiangzhao Ji, Ting Wang, Wenyan Wen, Rong Cui, Yanxia Chen, Junsheng Lia, Guohui College of Physics and Optoelectronics Key Laboratory of Interface Science and Engineering in Advanced Materials Key lab of Advanced Transducers and Intelligent Control System of Ministry of Education Taiyuan University of Technology Taiyuan030024 China School of Materials Science and Engineering Kunming University of Science and Technology Kunming650093 China Shanxi-Zheda institute of advanced materials and chemical engineering China Nano-Science Center Department of Chemistry University of Copenhagen Universitetsparken 5 CopenhagenDK-2100 Denmark

Submicron scale temperature sensors are crucial for a range of applications, particularly in micro and nanoscale environments. One promising solution involves the use of active whispering gallery mode (WGM) microresonators. These resonators can be remotely excited and read out using free-space structures, simplifying the process of sensing. In this study, we present a submicron-scale temperature sensor with a remarkable sensitivity up to 190 pm/℃ based on a triangular CH3NH3PbI3 nanoplatelet (NPL) laser. Notably, as temperature changes, the peak wavelength of the laser line shifts linearly. This unique characteristic allows for precise temperature sensing by tracking the peak wavelength of the NPL laser. The optical modes are confined within the perovskite NPL, which measures just 85 nanometers in height, due to total internal reflection. Our NPL laser boasts several key features, including a high Q-factor of ~ 2610 and a low laser threshold of about 19.8 µJ cm−2. The combination of exceptional sensitivity and ultra-small size makes our WGM device an ideal candidate for integration into systems that demand compact temperature sensors. This advancement paves the way for significant progress in the development of ultrasmall temperature sensors, opening new possibilities across various fields. © 2024, The Authors. All rights reserved.

关键词： Perovskite

Sampling Path Planned Transmission Matrix for Imaging Through Scattering Media

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SSRN 2023年

作者： Zheng, Shuoning Zhao, Wenjing Zhai, Aiping Wang, Dong College of Physics and Optoelectronics Taiyuan University of Technology No. 79 West Main Street Yingze030024 China Key Laboratory of Advanced Transducers and Intelligent Control System Ministry of Education and Shanxi Province Taiyuan University of Technology No. 79 West Main Street Yingze030024 China

For measuring a transmission matrix (TM) of a scattering medium, the normal way requires a large number of measurements, resulting in significant measurement time and storage consumption. Here, we propose to do imaging through scattering media using an undersampled TM measured by following an artificial planning path. Based on the spectral characteristics of the Hadamard transform (HT) of natural images, a sampling path for the TM measurement can be artificially planned, which guarantees the method to preferentially measure components in TM in relation to the more important spectra and ignore spectra that are drowned out by noise. For a natural target scene, it is normally sparse. This means our method can reduce a lot of measurements and storage consumption, thus improving the imaging speed while only sacrificing a little imaging quality. The results of the simulations and experiments agree with each other, suggesting that the proposed method is effective. © 2023, The Authors. All rights reserved.

关键词： Hadamard transforms

Vibration absorption of parallel-coupled nonlinear energy sink under shock and harmonic excitations

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Applied Mathematics and Mechanics(English Edition) 2021年第8期42卷 1135-1154页

作者： Jian’en CHEN Wei ZHANG Jun LIU Wenhua HU Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical EngineeringTianjin University of TechnologyTianjin 300384China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of TechnologyTianjin 300384China Beijing Key Laboratory of Nonlinear Vibrations and Strength of Mechanical Structures College of Mechanical EngineeringBeijing University of TechnologyBeijing 100124China

Nonlinear energy sink(NES)can passively absorb broadband energy from primary *** multiple NESs connected in parallel exhibit superior performance to single-degree-of-freedom(SDOF)*** this work,a linear coupling spring is installed between two parallel NESs so as to expand the application scope of such vibration *** vibration absorption of the parallel and parallel-coupled NESs and the system response induced by the coupling spring are *** results show that the responses of the system exhibit a significant difference when the heavier cubic oscillators in the NESs have lower stiffness and the lighter cubic oscillators have higher ***,the efficiency of the parallel-coupled NES is higher for medium shocks but lower for small and large shocks than that of the parallel *** parallel-coupled NES also shows superior performance for medium harmonic excitations until higher response branches are *** performance of the parallel-coupled NES and the SDOF NES is *** is found that,regardless of the chosen SDOF NES parameters,the performance of the parallel-coupled NES is similar or superior to that of the SDOF NES in the entire force range.

关键词： coupling influence nonlinear energy sink(NES) vibration absorption

A Novel Frequency Estimation Strategy and Filter Based on the Gearbox Response Mechanism Model

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SSRN 2024年

作者： Li, Decai Chen, Jiwei Xie, Ruitong Luo, Zhiweng Sheng, Yanliang Hu, Mantang Wang, Guofeng Zhang, Mian Key Laboratory of Mechanism Theory and Equipment Design Ministry of Education School of Mechanical Engineering Tianjin University Tianjin300072 China Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin300384 China

In the gearbox response signal, numerous sideband components generated by different fault characteristic frequencies are interleaved. Coupled with the noise interference, this makes health monitoring based on spectral analysis highly challenging. Traditional filtering methods, such as low-pass, high-pass and band-pass filters, and mode decomposition methods, exhibit limitations in filtering out interference signals over the entire frequency spectrum. Moreover, the absence of speed information complicates the determination of appropriate passbands. Most critically, noise within the passband is entirely retained. To address these issues, this paper proposes a methodology for estimating characteristic frequencies and filtering interference signals based on a novel response mechanism model (RMM) of gearbox. The proposed RMM model takes into account the structural attributes and vibration response mechanism of the gearbox, describing the modulation phenomena of fault characteristic frequencies on the meshing frequency and its harmonics. The proposed model-based frequency estimation (MFE) strategy accurately computes characteristic frequencies even in the absence of speed information. Additionally, the proposed model-based filter (MF) can perform accurate filtering over the entire frequency spectrum or within specified gear train vibration responses. Numerical simulations and experimental data validate the viability and effectiveness of the proposed methods. © 2024, The Authors. All rights reserved.

关键词： Frequency estimation

USING DEEP LEARNING FOR AUTOMATIC DEFECT DETECTION ON A SMALL WELD X-RAY IMAGE DATASET

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UPB Scientific Bulletin, Series C: Electrical Engineering an...

UPB Scientific Bulletin, Series C: Electrical Engineering and Computer Science 2022年第2期84卷 267-278页

作者： Zheng, Qingchun Li, Xiaoyang Zhu, Peihao Ma, Wenpeng Liu, Jingna Liu, Qipei Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin300384 China China

The quality of welding is directly related to the performance and life of welded products. This paper proposes an automatic defect detection method using deep learning on a small weld X-ray image dataset. Combined with Generative Adversarial Network (GAN) and Deep Convolutional Neural Network (DCNN), this method can successfully deal with the problem of data imbalance in small image dataset and achieves a good detection effect for low-contrast defect images. Extensive experiments have proved that this approach could accurately and quickly complete the location and detection task of internal defects of welds, and it achieves the Mean Average Precision (mAP) result as 91.64%. © 2022, Politechnica University of Bucharest. All rights reserved.

关键词： Defects

Coal Flow Volume Detection Method for Conveyor Belt Based on Tof Vision

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SSRN 2023年

作者： Hou, Chengcheng Qiao, Tiezhu Dong, Huijie Wu, Hongwang College of Electronic Information and Optical Engineering Taiyuan University of Technology Taiyuan030024 China Key Laboratory of Advanced Transducers and Intelligent Control System Ministry of Education Taiyuan University of Technology Taiyuan030024 China Shanxi Xinyuan Coal Co. Ltd. Jinzhong030600 China

Coal flow volume is the essential basic data support for intelligent speed regulation and energy-saving control of coal mine transportation systems. To accurately measure the coal flow volume of conveyor belts, an innovative coal flow volume detection method for conveyor belts based on TOF vision was proposed in the paper. Both depth and grayscale images of the coal flow were collected by a TOF camera. Then an improved fast marching method based on the grayscale image was used to achieve depth image restoration. The coal flow volume of conveyor belts could be calculated by using the surface fitting method. Experimental results demonstrate that the coal flow detection accuracy of the proposed method can reach 97.35%, and the single-frame image processing time is less than 70.72ms. The proposed method is verified to meet the accuracy and real-time requirements of coal mines. © 2023, The Authors. All rights reserved.

关键词： Belt conveyors

Nonlinear vibration mechanism of elastic beam in large overall rotation with rotor eccentricity effect

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Nonlinear vibration mechanism of elastic beam in large overa...

2021 International Conference on Mechanical Engineering, intelligent Manufacturing and Automation Technology, MEMAT 2021

作者： Zhao, Lei Yan, Zhao-Fang Zhao, Xin-Hua Li, Bin Tianjin Key Laboratory of the Design and Intelligent Control of the Advanced Mechatronical System Tianjin China Tianjin China School of Mechanic Engineering Tianjin University of Technology Tianjin China

The eccentric effect of rotor has seriously affected on the stability and precision of the mechanism at high speed for light and flexible mechanism in industrial application. The analysis of nonlinear vibration mechanism must be completed to realize precision and stable control of elastic beam in a large overall rotation. Firstly, the slender flexible rod is assumed as Euler-Bernoulli beam. We apply the deformation theory of elastic beam to establish its kinematic constraint relationship. Its dynamic model is built with Galerkin method and Hamilton principle. Then the Lagrange method is used to establish the rotor dynamics model based on the Jeffcott rotor. The coupling part between the motor and the elastic beam is assumed to be rigidly connected, and the dynamic model of the motor-elastic beam system can be obtained. Lastly, we analyze the nonlinear vibration mechanism of the elastic beam with rotor eccentricity effect through applying the fourth-order Runge-Kutta method and the superposition principle of traveling wave. It provides an important theoretical basis for making an effective vibration suppression strategy for elastic beam. © Published under licence by IOP Publishing Ltd.

关键词： Dynamic models

STUDY ON THE CENTERLINE EXTRACTION METHOD OF WELD IMAGE LINE STRUCTURED LIGHT STRIPE

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UPB Scientific Bulletin, Series C: Electrical Engineering an...

UPB Scientific Bulletin, Series C: Electrical Engineering and Computer Science 2022年第1期84卷 21-32页

作者： Zheng, Qingchun Liu, Qipei Zhu, Peihao Ma, Wenpeng Liu, Jingna Li, Xiaoyang Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin300384 China China

In practice, using vision measurement technology based on structured light to reconstruct the complex weld is a feasible way for providing the essential parameters for the welding polishing robot and guiding it to grind the weld by force control. In this paper, we represent a method to extract the centerline of structured light stripe in weld image. First, obtains the high-quality light stripe image using an industrial camera outfitted with a filter and preprocessed to isolate the entire structured light stripe from the background image. Second, using the weighted gray centroid method, roughly extract the original stripe center to obtain the initial point of the stripe center. Then, using principal component analysis, find the normal direction of the light stripe and calculate the gray distribution function of the stripe using second-order Taylor expansion along the normal direction to obtain the correct position of the stripe center. Finally, use cubic spline interpolation to create a smooth centerline. The testing results suggest that this method outperforms the Steger algorithm in terms of speed and extraction accuracy when compared to the classic gray centroid method. These works set the foundation for real-time 3D reconstruction of welds. © 2022, Politechnica University of Bucharest. All rights reserved.

关键词： Principal component analysis

OPTIMISATION OF SELF-PUNCHING RIVETING PROCESS PARAMETERS FOR HIGH-SPEED RAIL TOP PLATES

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UPB Scientific Bulletin, Series D: Mechanical Engineering 2022年第4期84卷 197-210页

作者： Zheng, Qingchun Guo, Chengmin Zhu, Peihao Liu, Jiaqi Ma, Wenpeng Zhao, Shuoshuo Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin300384 China China

To improve the quality of self-pierce riveted joints, this paper uses a multi-objective optimisation method that incorporates a quadratic polynomial response surface model and the NSGA-II algorithm to optimise the parameters of the self-pierce riveting process. First, we carry out finite element simulations of the self-pierce riveted joint to determine the main factors affecting the quality of the joint forming through sensitivity analysis, and specify the optimum range of each parameter. Second, we use central composite design experiments to establish a quadratic polynomial response surface model. Third, we optimise the multi-objective model by using the NSGA-II algorithm and obtain the Pareto optimal solution. Finally, we use cross-sectional measurement and mechanical properties experiments to verify the feasibility of optimising the self-pierce riveted joint. The experimental results show that the bottom thickness increases by 24.7%, the undercut amount by 14.5%, and the tensile shear force by 27% compared to the pre-optimisation period. The quality of the riveted joints was significantly improved after optimisation, laying a good foundation for improving the safety of high-speed railway bodies. © 2022, Politechnica University of Bucharest. All rights reserved.

关键词： Multiobjective optimization