10 research outputs found

    Minimum Norm Partial Quadratic Eigenvalue Assignment Using Receptances and System Matrices

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    振动控制广泛用于许多振动结构体的设计、维护和评估.这主要包括大型挠性空间结构控制、多体动力学系统控制、地震工程控制、阻尼陀螺系统稳定性控制、机器人控制设计以及结构动力学中的振动控制等工程领域. 在实际工程应用中,振动结构体往往通过有限元方法等离散技巧被离散为一个二阶常微分控制系统,其中系数矩阵代表分配物理参数矩阵,如质量矩阵、阻尼矩阵和刚度矩阵等.但是,通过该二阶模型计算得到的自然频率和模态(即特征值和特征向量)与通过对实际振动结构体测量得到的自然频率和模态往往不一致.一个有效的办法就是采用主动反馈控制,即利用反馈控制外力使得结构体满足测量或指定的自然频率而且剩余的地自然频率和模态保持不变,...Vibration control is widely used in the design, maintenance, and evaluation of many vibrating structures in engineering, which includes the control of large flexible space structures, the control of mechanical multibody systems, earthquake engineering,stabilization of damped gyroscopic systems, robotics, and vibration control in structural dynamics, etc. In practical engineering applica...学位:理学硕士院系专业:数学科学学院_计算数学学号:1902014115260

    Measurement of integrated luminosity of data collected at 3.773 GeV by BESIII from 2021 to 2024*

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    Determination of the number of ψ(3686) events taken at BESIII

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    The number of ψ(3686) events collected by the BESIII detector during the 2021 run period is determined to be (2259.3±11.1)×106 by counting inclusive ψ(3686) hadronic events. The uncertainty is systematic and the statistical uncertainty is negligible. Meanwhile, the numbers of ψ(3686) events collected during the 2009 and 2012 run periods are updated to be (107.7±0.6)×106 and (345.4±2.6)×106, respectively. Both numbers are consistent with the previous measurements within one standard deviation. The total number of ψ(3686) events in the three data samples is (2712.4±14.3)×10^

    Amplitude analysis of the decays D0π+ππ+πD^0\rightarrow\pi^+\pi^-\pi^+\pi^- and D0π+ππ0π0D^0\rightarrow\pi^+\pi^-\pi^0\pi0

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    Measurement of integrated luminosity of data collected at 3.773 GeV by BESIII from 2021 to 2024

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    We present a measurement of the integrated luminosity e+e- of collision data collected by the BESIII detector at the BEPCII collider at a center-of-mass energy of Ecm = 3.773 GeV. The integrated luminosities of the datasets taken from December 2021 to June 2022, from November 2022 to June 2023, and from October 2023 to February 2024 were determined to be 4.995±0.019 fb-1, 8.157±0.031 fb-1, and 4.191±0.016 fb-1, respectively, by analyzing large angle Bhabha scattering events. The uncertainties are dominated by systematic effects, and the statistical uncertainties are negligible. Our results provide essential input for future analyses and precision measurements

    Prediction of Energy Resolution in the JUNO Experiment

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    International audienceThis paper presents the energy resolution study in the JUNO experiment, incorporating the latest knowledge acquired during the detector construction phase. The determination of neutrino mass ordering in JUNO requires an exceptional energy resolution better than 3% at 1 MeV. To achieve this ambitious goal, significant efforts have been undertaken in the design and production of the key components of the JUNO detector. Various factors affecting the detection of inverse beta decay signals have an impact on the energy resolution, extending beyond the statistical fluctuations of the detected number of photons, such as the properties of liquid scintillator, performance of photomultiplier tubes, and the energy reconstruction algorithm. To account for these effects, a full JUNO simulation and reconstruction approach is employed. This enables the modeling of all relevant effects and the evaluation of associated inputs to accurately estimate the energy resolution. The study reveals an energy resolution of 2.95% at 1 MeV. Furthermore, the study assesses the contribution of major effects to the overall energy resolution budget. This analysis serves as a reference for interpreting future measurements of energy resolution during JUNO data taking. Moreover, it provides a guideline in comprehending the energy resolution characteristics of liquid scintillator-based detectors

    JUNO Sensitivity on Proton Decay pνˉK+p\to \bar\nu K^+ Searches

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    The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in pνˉK+p\to \bar\nu K^+ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via pνˉK+p\to \bar\nu K^+ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is 9.6×10339.6 \times 10^{33} years, competitive with the current best limits on the proton lifetime in this channel

    JUNO sensitivity on proton decay p → ν K + searches*

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    The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this study, the potential of searching for proton decay in the pνˉK+ p\to \bar{\nu} K^+ mode with JUNO is investigated. The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via pνˉK+ p\to \bar{\nu} K^+ is 36.9% ± 4.9% with a background level of 0.2±0.05(syst)±0.2\pm 0.05({\rm syst})\pm 0.2(stat) 0.2({\rm stat}) events after 10 years of data collection. The estimated sensitivity based on 200 kton-years of exposure is 9.6×1033 9.6 \times 10^{33} years, which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies

    JUNO sensitivity on proton decay pνK+p → νK^{+} searches

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