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Improved RIP-based performance guarantees for multipath matching pursuit

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Science China(Information Sciences) 2018年第10期61卷 173-186页

作者： Juan ZHAO xia bai Ran TAO School of Information and Electronics Beijing Institute of Technology Beijing Key Laboratory of Fractional Signals and Systems Beijing Institute of Technology

The multipath matching pursuit(MMP) is a generalization of the orthogonal matching pursuit(OMP), which generates multiple child paths for every candidate in each iteration and selects the candidate having the minimal residual as the final support set when iteration ends. In this paper we analyze its performance in both noiseless and noisy cases. The restricted isometry property(RIP)-based condition of MMP that ensures accurate recovery of sparse signals in the noiseless case is derived by using a simple technique. The performance guarantees of the MMP for support recovery in noisy cases are also *** is shown that under certain conditions on the RIP and minimum magnitude of nonzero components of the sparse signal, the MMP will exactly recover the true support of the sparse signal in cases of bounded noises and recover the true support with a high probability in the case of Gaussian noise. Our bounds on the RIP improve the existing results.

关键词： compressed sensing(CS) sparse signal reconstruction multipath matching pursuit(MMP) support recovery restricted isometry property(RIP)

基于OBE的问题式教学在师范生课程教学中的实践探索——以“中国地理”为例

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西华师范大学学报（自然科学版） 2025年第1期46卷 104-110页

作者：黄齐珍张白峡绵阳师范学院资源环境工程学院四川绵阳621006 四川省教育科学研究院成都610000

师范生既是学生又是职前教师,因此师范生培养既要提升其学科素养,又要训练其教学技能。文章以“中国地理”课程教学为例,基于OBE理念,以学生为中心,通过树立主动学习理念、构建课程内容框架、实践探索逐级训练、开展多元综合评价等策略... 详细信息

师范生既是学生又是职前教师,因此师范生培养既要提升其学科素养,又要训练其教学技能。文章以“中国地理”课程教学为例,基于OBE理念,以学生为中心,通过树立主动学习理念、构建课程内容框架、实践探索逐级训练、开展多元综合评价等策略,探索问题式教学在师范生课程教学中的实践应用,既让师范生掌握“为什么学”“学什么”“怎么学”和“学得怎样”,培养了师范生的地理核心素养,又让师范生把握“为什么教”“教什么”“怎么教”和“教得怎样”,提升了师范生的地理教学技能,有效提高了地理师范生的培养效果。

关键词：问题式教学 OBE 师范生课程教学实践

Voltage control of magnetization switching and dynamics

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Chinese Physics B 2018年第6期27卷 443-447页

作者： Hong-Yu Wen Jian-bai xia The State Key Laboratory of Superlattices and Microstructures Institute of Semiconductors Chinese Academy of Sciences Beijing 100083 China

The voltage controlled magnetic switching effect is verified experimentally. The Landau–Lifshitz–Gilbert（LLG）equation is used to study the voltage controlled magnetic switching. It is found that the initial values of magnetic moment components are critical for the switching effect, which should satisfy a definite condition. The external magnetic field which affects only the oscillation period should be comparable to the internal magnetic field. If the external magnetic field is too small, the switching effect will disappear. The precessions of mx and my are the best for the tilt angle of the external magnetic field θt = 0？, i.e., the field is perpendicular to the sample plane.

关键词： magnetic switching voltage control spin transfer torque Landau-Lifshitz-Gilbert (LLG) equa- tion

Spin flip in single quantum ring with Rashba spin–orbit interation

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Chinese Physics B 2018年第3期27卷 397-400页

作者： Duan-Yang Liu Jian-bai xia College of Science Beijing University of Chemical Technology Beijing 100029 China State Key Laboratory for Superlattice and Microstructures Institute of Semiconductors Chinese Academy of Sciences Beijing 100083 China

We theoretically investigate spin transport in the elliptical ring and the circular ring with Rashba spin-orbit interaction. It is shown that when Rashba spin-orbit interaction is relatively weak, a single circular ring can not realize spin flip, however an elliptical ring may work as a spin-inverter at this time, and the influence of the defect of the geometry is not obvious. Howerver if a giant Rashba spin-orbit interaction strength has been obtained, a circular ring can work as a spin-inverter with a high stability.

关键词： Rashba spin-orbit interaction quantum waveguide Aharonov-Bohm ring spin flip spin device

Block Compressed Sensing Image Reconstruction Based on SL0 Algorithm

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Journal of Beijing Institute of Technology 2017年第3期26卷 357-366页

作者： Juan Zhao xia bai Jieqiong xiao School of Information and Electronics Beijing Institute of TechnologyBeijing 100081China Beijing Key Laboratory of Fractional Signals and Systems Beijing 100081China)

By applying smoothed l0norm（SL0）algorithm,a block compressive sensing（BCS）algorithm called BCS-SL0 is proposed,which deploys SL0 and smoothing filter for image ***,BCS-ReSL0 algorithm is developed to use regularized SL0（ReSL0）in a reconstruction process to deal with noisy *** study shows that the proposed BCS-SL0 takes less execution time than the classical BCS with smoothed projected Landweber（BCS-SPL）algorithm in low measurement ratio,while achieving comparable reconstruction quality,and improving the blocking artifacts *** experiment results also verify that the reconstruction performance of BCS-ReSL0 is better than that of the BCSSPL in terms of noise tolerance at low measurement ratio.

关键词： compressed sensing (CS) block smoothed l0 norm (SLO)

A Novel Long-Time Coherent Integration Method for Moving Target Detection

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Journal of Beijing Institute of Technology 2021年第4期30卷 340-351页

作者： xia bai Yan Wang Juan Zhao Ran Tao School of Information and Electronics Beijing Institute of TechnologyBeijing 100081China

Long-time coherent integration(LTCI)can remarkably improve the detection ability of radar for moving *** increase the processing efficiency,this paper proposes a novel LTCI method based on segment time reversing transform(STRT)and chirp z-transform(CZT).In this method,STRT operation is first presented to estimate the Doppler ambiguity factor,and keystone transform(KT)is used to correct the whole range migration(RM).Then,CZT and non-uniform fast Fourier transform(NUFFT)are used to estimate the parameters as well as correct the second and third order Doppler frequency migration(DFM).Compared with the existing methods,the proposed method can achieve RM correction and DFM correction without repetitive *** effectiveness of the proposed method is validated by both simulated and real data.

关键词： long-time coherent integration range migration Doppler frequency migration

Frequency-,radiation pattern-and polarization-reconfigurable antenna for wireless applications

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The Journal of China Universities of Posts and Telecommunications 2023年第1期30卷 87-92页

作者： bai xia Su Ming Wang Qingmin Liu Yang Gao Zhiwei School of Information Science and Technology Shijiazhuang Tiedao UniversityShijiazhuang 050043China School of Electronic Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China

In this communication,a frequency-,radiation pattern-and polarization-reconfigurable antenna employing liquid metal is *** crossed dipole antennas are surrounded by four independent reflectors and directors to realize multi-beam *** length of dipole arms can be adjusted by extracting the liquid metal from the needle tube to achieve frequency *** polarization can be switched by injecting liquid metal into different dipole microfluidic *** is simple in design and has multiple reconfigurable *** antenna with a relative frequency tuning range of 35.8%extending from 2.43 GHz to 3.49 GHz is *** also can perform 6 kinds of beam steering over a 360°coverage and switch between two different *** antenna has potential to employ cognitive radio(CR)and base station in wireless systems.

关键词： reconfigurable antenna liquid metal crossed dipoles reflectors compound reconfiguration

Experimental investigation of wall-bounded turbulence drag reduction by active control of double piezoelectric vibrator

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Journal of Hydrodynamics 2020年第4期32卷 747-757页

作者： Jian-xia bai Yong-xiang Huang Nan Jiang Xing-yu Ma Zhan-qi Tang Department of Mechanics School of Mechanical EngineeringTianjin UniversityTianjin 300354China Department of Mathematics Tianjin University Renai CollegeTianjin 301636China State Key Laboratory of Marine Environmental Science College of Ocean and Earth SciencesXiamen UniversityXiamen 361102China Tianjin Key Laboratory of Modern Engineering Mechanics Tianjin 300354China

In order to manipulate the large-scale coherent structures in the wall-bounded turbulence and reduce the skin-friction,an active-control experimental investigation is performed by using the synchronous and asynchronous vibrations of double piezoelectric vibrators embedded spanwisely on a smooth flat plate surface.A TSI-IFA300 hot-wire anemometer and a TSI-1621 A-Tl.5 hot-wire probe are used to measure the time series of the instantaneous velocity at different *** influences of the vibrations on the wall-bounded turbulence are compared in a multi-scale point of view.A disturbance Reynolds Number Red=pd2 f/μis introduced to represent the disturbance.A probability density functions(PDFs)of the multi-scale components of the turbulence velocity and the multi-scale conditional phase-averaged waveform are studied in detail using the wavelet *** results show that the maximum drag reduction rate 18.54%is obtained at 100 V/160 Hz and Red=0.54 in the asynchronous vibration *** disturbances generated by the vibrators have a significant influence on the sweep events of the *** asynchronous vibration model is more effective than the synchronous vibration one.A possible physical mechanism is suggested to explain why the disturbance frequency of 160 Hz leads to an optimal parameter set for the drag reduction.

关键词： Wall-bounded turbulence active control drag reduction piezoelectric vibrator multi-scale analysis conditional phase-averaged wavefonns coherent structure

MiRNA-145-5p inhibits gastric cancer progression via the serpin family E member 1-extracellular signal-regulated kinase-1/2 axis

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World Journal of Gastrointestinal Oncology 2024年第5期16卷 2123-2140页

作者： Hong-xia bai Xue-Mei Qiu Chun-Hong Xu Jian-Qiang Guo Department of Gastroenterology The Second Hospital of Shandong UniversityJinan 250000Shandong ProvinceChina Department of Gastroenterology Liaocheng People’s HospitalLiaocheng 252000Shandong ProvinceChina Department of Reproductive Center Zaozhuang Maternal and Child Health Care HospitalZaozhuang 277000Shandong ProvinceChina

BACKGROUND MicroRNAs(miRNAs)regulate gene expression and play a critical role in cancer ***,there is still a limited understanding of the function and regulatory mechanism of miRNAs in gastric cancer(GC).AIM To investigate the role and molecular mechanism of miRNA-145-5p(miR145-5p)in the progression of *** Real-time polymerase chain reaction(RT-PCR)was used to detect miRNA expression in human GC tissues and *** ability of cancer cells to migrate and invade was assessed using wound-healing and transwell assays,*** proliferation was measured using cell counting kit-8 and colony formation assays,and apoptosis was evaluated using flow *** of the epithelial-mesenchymal transition(EMT)-associated protein was determined by Western *** of miR-145-5p were predicated using bioinformatics analysis and verified using a dual-luciferase reporter *** family E member 1(SERPINE1)expression in GC tissues and cells was evaluated using RT-PCR and immunohistochemical *** correlation between SERPINE1 expression and overall patient survival was determined using Kaplan-Meier plot *** association between SERPINE1 and GC progression was also tested.A rescue experiment of SERPINE1 overexpression was conducted to verify the relationship between this protein and *** mechanism by which miR-145-5p influences GC progression was further explored by assessing tumor formation in nude *** GC tissues and cells had reduced miR-145-5p expression and SERPINE1 was identified as a direct target of this *** of miR-145-5p was associated with decreased GC cell proliferation,invasion,migration,and EMT,and these effects were reversed by forcing SERPINE1 ***-Meier plot analysis revealed that patients with higher SERPINE1 expression had a shorter survival rate than those with lower SERPINE1 *** mouse tumorigenesis experiments confirmed that miR-145-5p target

关键词： Gastric cancer MicroRNA-145-5p Serpin family E member 1 Epithelial-mesenchymal transition Proliferation Extracellular signal-regulated kinase-1/2