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Physical parameter estimation with MCMC from observations of Vela X-1

High Power Laser Science and Engineering 2018年第2期6卷 202-212页

作者： Lan Zhang feilu wang Xiangxiang Xue Dawei Yuan Huigang Wei Gang Zhao Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100012China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 101408China Graduate School of China Academy of Engineering Physics Beijing 100196China

We present a parameter estimate for continua, and He-like triplets of the high resolution X-ray spectra with a Bayesian inference and a Markov Chain Monte Carlo(MCMC) tool. The method is applied for Vela X-1 with three different orbital phases(φ), Eclipse, φ = 0.25, and φ = 0.5, which are adopted from the Chandra High-Energy Transmission Grating Spectrometer(HETGS). A parameterized two-component power-law model [Sako et al., Astrophys. J. 525, 921(1999)] and a multi-Gaussian model are applied to model these continua and He-like triplets, respectively. A uniform distribution over each parameter is used as the prior belief. Posterior probability distribution functions of parameters and the covariances among them are explored by using the MCMC method. The main advantages are(i) all model-based parameters are set to be free instead of artificially fixing some of the parameters during the data-model fitting;(ii) the contributions from satellite lines are considered;(iii) backgrounds are treated as a correction to the observation errors;and(iv) the confidence interval of each parameter is given. The fitted results show that the column density of scatter component(N_H^(scat)) varies from phase to phase, which imply a non-spherical structure of the stellar wind in Vela ***, the wind velocities derived from main lines of each set of He-like triplets show better self-consistency than those in previous publications, which could provide a reliable approach for the diagnostics of photoionized plasma in astrophysical objects and the laboratory.

关键词： data analysis satellite lines X-ray spectra

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Preliminary Exploration of Areal Density of Angular Momentum for Spiral Galaxies

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Research in Astronomy and Astrophysics 2023年第8期23卷 1-4页

作者： Lan Zhang feilu wang Xiangxiang Xue David Salzmann Baifei Shen Zehao Zhong Gang Zhao CAS Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 101408China Institute for Frontiers in Astronomy and Astrophysics Beijing Normal UniversityBeijing 102206China Department of Physics Shanghai Normal UniversityShanghai 200234China

The specific angular momenta(j_(t))of stars,baryons as a whole and dark matter halos contain clues of vital importance about how galaxies form and *** a sample of 70 spiral galaxies,we perform a preliminary analysis of j_t,and introduce a new quantity,e.g.,areal density of angular momentum(ADAM)(j_(t)M_(*)/(2R_(d))^(2))as an indication for the existence of jet(s)in spiral *** percentage of spiral galaxies having jet(s)shows a strong correlation with ADAM,although the present sample is incomplete.

关键词： galaxies jets-galaxies spiral-galaxies statistics

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Emission mechanism for the silicon He-α lines in a photoionization experiment

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High Power Laser Science and Engineering 2021年第1期9卷 86-93页

作者： Bo Han feilu wang David Salzmann Jiayong Zhong Gang Zhao Department of Astronomy Beijing Normal UniversityBeijing 100875China College of Physics and Electronic Engineering Qilu Normal UniversityJinan 250200China CAS Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 101408China Graduate School of China Academy of Engineering Physics Beijing 100196China Collaborative Innovation Center of IFSA(CICIFSA) Shanghai Jiao Tong UniversityShanghai 200240China

In this paper, we present a reanalysis of the silicon He-α X-ray spectrum emission in Fujioka et al.’s 2009 photoionization experiment. The computations were performed with our radiative-collisional code, RCF. The central ingredients of our computations are accurate atomic data, inclusion of satellite lines from doubly excited states and accounting for the reabsorption of the emitted photons on their way to the spectrometer. With all these elements included, the simulated spectrum turns out to be in good agreement with the experimental spectrum.

关键词： high-energy-density physics laboratory astrophysics laser–plasma interaction

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Generation of strong magnetic fields with a laser-driven coil

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High Power Laser Science and Engineering 2018年第3期6卷 1-8页

作者： Zhe Zhang Baojun Zhu Yutong Li Weiman Jiang Dawei Yuan Huigang Wei Guiyun Liang feilu wang Gang Zhao Jiayong Zhong Bo Han Neng Hua Baoqiang Zhu Jianqiang Zhu Chen wang Zhiheng Fang Jie Zhang Beijing National Laboratory of Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing 100190 China School of Physical Sciences University of Chinese Academy of Sciences Beijing 100049 China Collaborative Innovation Center oflFSA (CICIFSA) Shanghai Jiao Tong University Shanghai 200240 China Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China Department of Astronomy Beijing Normal University Beijing 100875 China National Laboratory on High Power Laser and Physics Chinese Academy of Sciences Shanghai 201800 China Shanghai Institute of Laser Plasma Shanghai 201800 China Key Laboratory for Laser Plasmas (MoE) and Department of Physics and Astronomy Shanghai Jiao Tong University Shanghai 200240 China

As a promising new way to generate a controllable strong magnetic field, laser-driven magnetic coils have attracted interest in many research fields. In 2013, a kilotesla level magnetic field was achieved at the Gekko XII laser facility with a capacitor-coil target. A similar approach has been adopted in a number of laboratories, with a variety of targets of different shapes. The peak strength of the magnetic field varies from a few tesla to kilotesla, with different spatio- temporal ranges. The differences are determined by the target geometry and the parameters of the incident laser. Here we present a review of the results of recent experimental studies of laser-driven magnetic field generation, as well as a discussion of the diagnostic techniques required for such rapidly changing magnetic fields. As an extension of the magnetic field generation, some applications are discussed.

关键词： lab astrophysics laser-plasma interaction magnetic field plasma astrophysics

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Measurement and analysis of K-shell lines of silicon ions in laser plasmas

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High Power Laser Science and Engineering 2018年第2期6卷 133-140页

作者： Bo Han feilu wang Jiayong Zhong Guiyun Liang Huigang Wei Dawei Yuan Baojun Zhu Fang Li Chang Liu Yanfei Li Jiarui Zhao Zhe Zhang Chen wang Jun Xiong Guo Jia Neng Hua Jianqiang Zhu Yutong Li Gang Zhao Jie Zhang Department of Astronomy Beijing Normal University Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences IFSA Collaborative Innovation Center Shanghai Jiao Tong University National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Research Center for Laser Fusion China Academy of Engineering Physics National Laboratory on High Power Laser and Physics Chinese Academy of Sciences Key Laboratory for Laser Plasmas (MoE) and Department of Physics and Astronomy Shanghai Jiao Tong University

We present laboratory measurement and theoretical analysis of silicon K-shell lines in plasmas produced by Shenguang II laser facility, and discuss the application of line ratios to diagnose the electron density and temperature of laser *** types of shots were carried out to interpret silicon plasma spectra under two conditions, and the spectra from 6.6 ?A to6.85 ?A were measured. The radiative-collisional code based on the flexible atomic code(RCF) is used to identify the lines, and it also well simulates the experimental spectra. Satellite lines, which are populated by dielectron capture and large radiative decay rate, influence the spectrum profile significantly. Because of the blending of lines, the traditional G value and R value are not applicable in diagnosing electron temperature and density of plasma. We take the contribution of satellite lines into the calculation of line ratios of He-α lines, and discuss their relations with the electron temperature and density.

关键词： high energy density physics laser plasmas interaction plasmas astrophysics

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基于径向基神经网络的蛋白质二级结构预测

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计算机工程与应用 2011年第20期47卷 17-19,23页

作者：王菲露宋杨安徽建筑工业学院电子与信息工程学院合肥230601 中国科学技术大学自动化系合肥230026 中国科学院合肥智能机械研究所合肥230031 安徽大学电子信息工程学院合肥230039

为提高蛋白质二级结构预测的精确度,提出并构建精确的径向基神经网络、广义回归神经网络,并基于5位编码和Profile编码,采用不同大小的滑动窗口,利用交叉检证法构建多个径向基网络预测器,分别对蛋白质二级结构进行预测,得到了较好的实验... 详细信息

为提高蛋白质二级结构预测的精确度,提出并构建精确的径向基神经网络、广义回归神经网络,并基于5位编码和Profile编码,采用不同大小的滑动窗口,利用交叉检证法构建多个径向基网络预测器,分别对蛋白质二级结构进行预测,得到了较好的实验结果,其中aveQ3提高到70.96%。结果表明,径向基神经网络模型能有效提高预测精确度,也证明了实验方法的有效性和可行性。

关键词：径向基神经网络蛋白质二级结构预测器

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RBF神经网络在柔性触觉传感器解耦中的应用

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计算机工程与应用 2015年第10期51卷 20-25页

作者：王菲露宋杨安徽建筑大学电子与信息工程学院合肥230601

针对柔性触觉传感器模型高度非线性、解耦难度大等问题,提出一种有效的方法来模拟柔性触觉传感器在实际应用中含噪声的情形。首先在理想条件下的传感器模型上添加不同幅度的高斯白噪声并建立其数学模型,之后通过K-均值和递归最小二乘法... 详细信息

针对柔性触觉传感器模型高度非线性、解耦难度大等问题,提出一种有效的方法来模拟柔性触觉传感器在实际应用中含噪声的情形。首先在理想条件下的传感器模型上添加不同幅度的高斯白噪声并建立其数学模型,之后通过K-均值和递归最小二乘法优化RBF神经网络,并利用优化后的RBF神经网络算法逼近受噪声干扰的传感器阻值与形变之间的高维非线性映射关系,最后基于不同的展开幅度通过行列阻值解耦出传感器三维形变信息,获得了较好的解耦精度。解耦结果表明,RBF神经网络算法具有较强的鲁棒性和抗噪声能力,能够很好地逼近含噪声的传感器高维非线性数据之间的映射关系。

关键词：柔性触觉传感器解耦 RBF神经网络高斯白噪声

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An investigation of the L-shell x-ray conversion efficiency for laser-irradiated tin foils

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Plasma Science and Technology 2020年第4期22卷 48-54页

作者： David BAILIE Cormac HYLAND Raj L SINGH Steven WHITE Gianluca SARRI Francis P KEENAN David RILEY Steven J ROSE Edward G HILL feilu wang Dawei YUAN Gang ZHAO Huigang WEI Bo HAN Baoqiang ZHU Jianqiang ZHU Pengqian YANG Centre for Plasma Physics School of Mathematics and PhysicsQueen's University BelfastBelfastBT7 INNUnited Kingdom Astrophysics Research Centre School of Mathematics and PhysicsQueen's University BelfastBelfastBT7 INNUnited Kingdom Plasma Physics Group Blackett LaboratoryPrince Consort RoadLondonSW72AZUnited Kingdom Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100012People's Republic of China Department of Astronomy Beijing Normal UniversityBeijing 100875People's Republic of China Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences.Shanghai 201800People's Republic of China

We have used the ShenguangⅡlaser in third harmonic(351 nm)to investigate the emission of L-shell radiation in the 3.3–4.4 ke V range generated using thin foils of Sn coated onto a parylene substrate with irradiation of order 1015 W cm-2 and nanosecond pulse *** our experiment,we have concentrated on assessing the emission on the non-laser irradiated side as this allows an experimental geometry relevant to experiments on photo-ionised plasmas where a secondary target must be placed close to the source,to achieve x-ray fluxes appropriate to astrophysical *** L-shell conversion efficiencies are estimated to be of order 1%,with little dependence on Sn thickness between 400 and 800 nm.

关键词： conversion efficiency laser plasma x-ray sources laboratory astrophysics

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基于新型柔性触觉传感器的摩尔斯电码分类识别研究

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传感技术学报 2024年第4期37卷 569-580页

作者：王菲露孙牛平宋杨蒋秀丽章王勇章英安徽建筑大学电子与信息工程学院安徽合肥230601

触觉是人类与外界联系的重要方式,在人机交互系统中赋予机器人触觉感知能力具有重要意义。基于聚偏氟乙烯(Polyvinylidene fluoride,PVDF)的压电特性、利用3D打印技术、设计并制备了一种具有高灵敏度(15.02 mV/N)的新型压电式柔性触觉... 详细信息

触觉是人类与外界联系的重要方式,在人机交互系统中赋予机器人触觉感知能力具有重要意义。基于聚偏氟乙烯(Polyvinylidene fluoride,PVDF)的压电特性、利用3D打印技术、设计并制备了一种具有高灵敏度(15.02 mV/N)的新型压电式柔性触觉传感器。通过在传感器表面轻敲“0~9”数字的摩尔斯电码,采集3000组传感器输出的4000维电压时序信号作为实验样本集。在此基础上构建具有强大特征提取能力的卷积神经网络(Convolutional Neural Network,CNN)与门控循环单元(Gated Recurrent Unit,GRU)的融合网络模型CNN-GRU,用以实现对数字“0~9”摩尔斯电码的识别,其平均识别准确率为98.17%。实验结果表明,所研究的新型柔性触觉传感器能够准确感知并区分不同摩尔斯电码的敲击模式,具有优良时序记忆能力的CNN-GRU模型能够很好地应用于柔性触觉传感器不同接触模式的分类识别。

关键词：压电式柔性触觉传感器分类识别 CNN-GRU模型摩尔斯电码接触模式

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Laboratory study of astrophysical collisionless shock at SG-Ⅱ laser facility

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High Power Laser Science and Engineering 2018年第3期6卷 65-72页

作者： Dawei Yuan Huigang Wei Guiyun Liang feilu wang Yutong Li Zhe Zhang Baojun Zhu Jiarui Zhao Weiman Jiang Bo Han Xiaoxia Yuan Jiayong Zhong Xiaohui Yuan Changbo Fu Xiaopeng Zhang Chen wang Guo Jia Jun Xiong Zhiheng Fang Shaoen Jiang Kai Du Yongkun Ding Neng Hua Zhanfeng Qiao Shenlei Zhou Baoqiang Zhu Jianqiang Zhu Gang Zhao Jie Zhang Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing 100190 China Department of Astronomy Beijing Normal University Beijing 100875 China Key Laboratory for Laser Plasmas (MoE) and Department of Physics and Astronomy Shanghai Jiao Tong University Shanghai 200240 China Collaborative Innovation Center oflFSA (CICIFSA) Shanghai Jiao Tong University Shanghai 200240 China INPAC and School of Physics and Astronomy Shanghai Jiao Tong University Shanghai Key Laboratory for Particle Physics and Cosmology Shanghai 200240 China Shanghai Institute of Laser Plasma Shanghai 201800 China Research Center for Laser Fusion China Academy of Engineering Physics Mianyang 621900 China National Laboratory on High Power Laser and Physics Chinese Academy of Sciences Shanghai 201800 China School of Astronomy and Space Science University of Chinese Academy of Sciences Beijing 101408 China School of Physical Sciences University of Chinese Academy of Sciences Beijing 100049 China

Astrophysical collisionless shocks are amazing phenomena in space and astrophysical plasmas, where supersonic flows generate electromagnetic fields through instabilities and particles can be accelerated to high energy cosmic rays. Until now, understanding these micro-processes is still a challenge despite rich astrophysical observation data have been obtained. Laboratory astrophysics, a new route to study the astrophysics, allows us to investigate them at similar extreme physical conditions in laboratory. Here we will review the recent progress of the collisionless shock experiments performed at SG-II laser facility in China. The evolution of the electrostatic shocks and Weibel-type/filamentation instabilities are observed. Inspired by the configurations of the counter-streaming plasma flows, we also carry out a novel plasma collider to generate energetic neutrons relevant to the astrophysical nuclear reactions.

关键词： collisionless shock electromagnetic field high power lasers laboratory astrophysics

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