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New Result on Delay-dependent Stability for Markovian Jump Time-delay Systems With Partial Information on Transition Probabilities

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IEEE/CAA Journal of Automatica Sinica 2019年第6期6卷 1499-1505页

作者： Yan Zhang Ke Lou Yuan Ge the College of Electrical Engineering Anhui Key Laboratory of Detection Technology and Energy Saving Devices Anhui Polytechnic University

This paper focuses on the delay-dependent stability for a kind of Markovian jump time-delay systems(MJTDSs),whose transition rates are incompletely known. In order to reduce the computational complexity and achieve better performance,auxiliary function-based double integral inequality is combined with extended Wirtinger's inequality and Jensen inequality to deal with the double integral and the triple integral in augmented Lyapunov-Krasovskii function(ALKF) and their weak infinitesimal generator respectively, the more accurate approximation bounds with a fewer variables are derived. As a result, less conservative stability criteria are proposed in this paper. Finally,numerical examples are given to show the effectiveness and the merits of the proposed method.

关键词： Auxiliary function-based double integral inequality delay-dependent stability Markovian jump time-delay systems(MJTDSs) unknown transition rates

Supercooled liquids analogous fractional Stokes–Einstein relation in NaCl solution above room temperature

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Chinese Physics B 2019年第7期28卷 381-388页

作者： Gan Ren Shikai Tian Departments of Physics & Key laboratory of Photonic and Optical detection in Civil Aviation Civil Aviation Flight University of China

The Stokes–Einstein relation D^T/η and its two variants D~τ-1 and D^T/τ follow a fractional form in supercooled liquids, where D is the diffusion constant, T the temperature,η the shear viscosity, and τ the structural relaxation *** fractional Stokes–Einstein relation is proposed to result from the dynamic heterogeneity of supercooled *** this work, by performing molecular dynamics simulations, we show that the analogous fractional form also exists in sodium chloride(NaCl) solutions above room temperature.D~τ-1 takes a fractional form within 300–800 K;a crossover is observed in both D^T/τ and D^T/η.Both D^T/τ and D^T/η are valid below the crossover temperature Tx,but take a fractional form for T > *** results indicate that the fractional Stokes–Einstein relation not only exists in supercooled liquids but also exists in NaCl solutions at high enough temperatures far away from the glass transition *** propose that D^T/η and its two variants should be critically evaluated to test the validity of the Stokes–Einstein relation.

关键词： sodium chloride solutions supercooled liquids molecular dynamics Stokes–Einstein relation

Terahertz-dependent identification of simulated hole shapes in oil gas reservoirs

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Chinese Physics B 2016年第10期25卷 30-34页

作者：宝日玛詹洪磊苗昕扬赵昆冯程静董晨李羿璋肖立志 State Key laboratory of Petroleum Resources and Prospecting China University of Petroleum Beijing Key laboratory of Optical detection Technology for Oil and Gas China University of Petroleum Key laboratory of Oil and Gas Terahertz Spectroscopy and Photoelectric detection China Petroleum and Chemical Industry Federation (CPCIF)

Detecting holes in oil–gas reservoirs is vital to the evaluation of reservoir potential. The main objective of this study is to demonstrate the feasibility of identifying general micro-hole shapes, including triangular, circular, and square shapes, in oil–gas reservoirs by adopting terahertz time-domain spectroscopy(THz-TDS). We evaluate the THz absorption responses of punched silicon(Si) wafers having micro-holes with sizes of 20 μm–500 μm. Principal component analysis(PCA) is used to establish a model between THz absorbance and hole shapes. The positions of samples in three-dimensional spaces for three principal components are used to determine the differences among diverse hole shapes and the homogeneity of similar shapes. In addition, a new Si wafer with the unknown hole shapes, including triangular, circular, and square, can be qualitatively identified by combining THz-TDS and PCA. Therefore, the combination of THz-TDS with mathematical statistical methods can serve as an effective approach to the rapid identification of micro-hole shapes in oil–gas reservoirs.

关键词： hole shapes oil–gas reservoirs THz-TDS PCA

Terahertz time-domain spectroscopy of a simulated pore structure to probe particle size and porosity of porous rock

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Chinese Physics B 2014年第12期23卷 476-480页

作者：董晨宝日玛赵昆许长虹金武军钟寿仙 State Key laboratory of Petroleum Resources and Prospecting China University of Petroleum Beijing Key laboratory of Optical detection Technology for Oil and Gas China University of Petroleum Key laboratory of Oil and Gas Terahertz Spectroscopy and Photoelectric detection China Petroleum and Chemical Industry Federation (CPCIF)

The particle sizes and porosities of simulated pore structures are probed by terahertz time-domain spectroscopy.A double-peak time-domain spectrum phenomenon is observed when the terahertz（THz） pulses illuminated a pore and a particle. The amplitudes of the two peaks depend strongly and monotonically on the particle size and porosity. A model is used to study the phenomenon, and the computational results agreed with the experimental measurements. These measurements indicate the terahertz spectroscopic behaviors of pores and particles, suggesting that terahertz spectroscopy can be used as a noncontact probe of porosity.

关键词： reservoir simulation physical optics terahertz spectroscopy polymer

F-μbond length andμSR depolarization spectrum calculation for fluoride using two-component density functional theory

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Chinese Physics B 2023年第8期32卷 120-123页

作者：潘智康邓力潘子文原钺张宏俊叶邦角 State Key laboratory of Particle detection and Electronics University of Science and Technology of ChinaHefei 230026China

First-principles calculation of muons in ionic fluorides has been proposed ***,there is a considerable difference between the obtained F-μbond length and the experimental data obtained by muon spin relaxation(μSR).Considering that the difference may be caused by ignoring the quantum effect of muons,we use two-component density functional theory(TCDFT)to consider the quantized muon and recalculate the bond length and theμSR depolarization *** testing several muon-electron correlation,we show that TCDFT can give better results than the commonly used“DFT+μ”.

关键词： muon spin relaxation/rotation fluoride density-functional theory

Integrating artificial intelligence into radiological cancer imaging: from diagnosis and treatment response to prognosis

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Cancer Biology & Medicine 2025年第1期22卷 6-13页

作者： Sunyi Zheng Xiaonan Cui Zhaoxiang Ye Tianjin Medical University Cancer Institute and Hospital National Clinical Research Center for Cancer Tianjin's Clinical Research Center for Cancer State Key Laboratory of Druggability Evaluation and Systematic Translational Medicine Tianjin Key Laboratory of Digestive Cancer Key Laboratory of Cancer Prevention and Therapy Department of Radiology

Cancer poses a serious threat to human health worldwide and is a leading cause of death1. The analysis of radiological imaging is crucial in early detection, accurate diagnosis, effective treatment planning, and ongoing monitoring of patients with cancer. However, several challenges impede the effectiveness of cancer imaging analysis in clinical practice.

关键词： intelligence prognosis imaging cancer from artificial diagnosis integrating into radiological

An Inverse Electromagnetic Scattering Method for One-Dimensional Inhomogeneous Media

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Chinese Physics Letters 2011年第1期28卷 82-85页

作者： LIN Zhi-Wei XU Xin ZHANG Xiao-Juan FANG Guang-You Key laboratory for Electromagnetic Radiation and detection Technology Institute of Electronics Chinese Academy of Sciences Beijing 100190

A frequency-domain inversion scheme for reconstructing the permittivity profile of one-dimensional inhomoge- neous media is proposed. The generalized reflection coefficients and the generalized transmission coefficients of the inhomogeneous media are used as the input data of the inverse model. A Newton-like iterative algorithm known as the generalized pulse-spectrum technique with the Tikhonov regularization is applied to solve the in- verse problem. Novel boundary conditions are proposed for the inverse problem and therefore the permittivity at the boundary of the inhomogeneous media is not required as prior knowledge. The choice of frequency points of the frequency-domain method is also investigated. Numerical examples are carried out to validate the inversion technique. Good agreements between the reconstructed profiles and the true profiles are shown.

关键词： Mathematical physics Accelerators beams and electromagnetism

Resolution-enhanced single-pixel imaging using the Hadamard transform matrix

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Chinese Physics B 2023年第12期32卷 652-656页

作者：别书航王晨晖吕瑞兵鲍倩倩付强孟少英陈希浩 Key laboratory of Optoelectronic Devices and detection Technology College of PhysicsLiaoning UniversityShenyang 110036China

We propose a single-pixel imaging(SPI)method to achieve a higher-resolution image via the Hadamard transform *** traditional SPI schemes,this new method recovers images by correlating single-pixel signals with synchronized transformed patterns of Hadamard bases that are actually projected onto the digital micromirror *** transform pattern is obtained through the inverse Fourier transform of the pattern acquired by Gaussian filtering of each Hadamard basis in the frequency *** proposed scheme is based on a typical SPI experimental setup and does not add any hardware complexity,enabling the transformation of Hadamard matrices and image reconstruction through data processing ***,this approach could be considered as an alternative option for achieving fast SPI in a diffraction-limited imaging system,without the need for additional hardware.

关键词： single-pixel imaging Gaussian filtering resolution enhancement

Non-contacting characterization of oil-gas interface with terahertz wave

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Science China(Physics,Mechanics & Astronomy) 2016年第7期59卷 84-85页

作者： DanDan Wang XinYang Miao HongLei Zhan Jin Wang Kun Zhao Beijing Key laboratory of Optical detection Technology for Oil and Gas China University of Petroleum

Dear Editors, The interface ofoil and gas has been a key issue in the process of oil and gas storage and transportation, which is a preparatory work to improve the transport efficiency and prevent oil and gas leaks. There are many methods to characterize the in- terface of oil and gas, such as the ultrasonic transducers and multi-electrode capacitance level sensors. Recently, the application of terahertz （THz） technique has attracted much at- tention in the characterization and evaluation of oil and gas [1-7], such as a magnetic-field-induced disaggregation of the size of suspended colloidal particles in crude oil and pattern transitions of oil-water two-phase flow [6,7]. THz time-do- main spectroscopy （THz-TDS） was expected to detect the interface of oil and gas since oil and gas can be characterized with THz wave. In this letter, a drop of crude oil with its volatile gas from an oilfield, which is inserted in the middle of a resin craft, was selected to probe the interface between oil and gas.

关键词：油气界面太赫兹波接触特性 THz-TDS 液位传感器超声换能器油水两相流挥发性气体