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Damping properties of fly ash/epoxy composites

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Journal of University of Science and Technology Beijing 2008年第4期15卷 509-513页

作者： jian gu Gaohui Wu Xiao Zhao School of Materials Science and Engineering Harbin Institute of Technology Harbin 150001 China

An inexpensive fly ash （FA）, which is from a waste product, was employed to prepare fly ash/epoxy composites. The purpose of this study is to characterize the contributions of matrix viscoelasticity, hollow structure characteristic （porosity）, and filler/matrix interface friction to the high vibration damping capacity of such composites. The damping properties of the composites were investigated in the temperature range of-40 to 150℃ and in the frequency range of 10 to 800 Hz by using a tension-compression mode. The results indicate that the peak value of damping loss factor （tan3） for the fly ash/epoxy composites can reach 0.70-0.90 in test specification, and the attenuation of damping loss factor is inconspicuous with increasing frequency. In addition, scanning electron microscope （SEM） was used to observe the morphology of the fly ash as well as its distribution in the matrix, which will help to analyze the effect of fly ash on the damping properties of the fly ash/epoxy composites.

关键词： composites epoxy fly ash damping property loss factor

The Origin of The Soft X-Ray Excess in the Seyfert 1.5 Galaxy ESO 362-G18

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Research in Astronomy and Astrophysics 2022年第3期22卷 10-32页

作者： Xiao-gu Zhong jian-Cheng Wang Yunnan Observatories Chinese Academy of SciencesKunming 650216China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of SciencesKunming 650216China University of Chinese Academy of Sciences Beijing 100049China

We review the Seyfert 1.5 Galaxy ESO 362-G18 for exploring the origin of the soft X-ray *** Warm Corona and Relativistic Reflection models are two main scenarios to interpret the soft X-ray excess in active galactic nuclei at *** use the simultaneous X-ray observation data of XMM-Newton and Nu STAR on2016 September 24 to perform spectral analysis in two ***,we analyze the time-average spectra by using Warm Corona and Relativistic Reflection ***,we also explore the Hybrid model,Double Reflection model and Double Warm Corona *** find that both the Warm Corona and Relativistic Reflection models can interpret the time-average spectra well but cannot be distinguished easily based on the time-averaged spectra fit ***,we add the rms and covariance spectra to perform the spectral analysis with time-average *** result shows that the warm corona could reproduce all of these spectra *** hot,optical thin corona and neutral distant reflection will increase their contribution with the temporal frequency,meaning that the corona responsible for X-ray continuum comes from the inner compact X-ray region and the neutral distant reflection is made of some moderate scale neutral clumps.

关键词： galaxies:active galaxies:individual(ESO 362-G18) galaxies:Seyfert

Truncated sparse approximation property and truncated q-norm minimization

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Applied Mathematics(A Journal of Chinese Universities) 2019年第3期34卷 261-283页

作者： CHEN wen-gu LI Peng Institute of Applied Physics and Computational Mathematics Beijing100088China Graduate School China Academy of Engineering PhysicsBeijing 100088China

This paper considers approximately sparse signal and low-rank matrix’s recovery via truncated norm minimization minx∥xT∥q and minX∥XT∥Sq from noisy *** first introduce truncated sparse approximation property,a more general robust null space property,and establish the stable recovery of signals and matrices under the truncated sparse approximation *** also explore the relationship between the restricted isometry property and truncated sparse approximation *** we also prove that if a measurement matrix A or linear map A satisfies truncated sparse approximation property of order k,then the first inequality in restricted isometry property of order k and of order 2k can hold for certain different constantsδk andδ2k,***,we show that ifδs(k+|T^c|)<√(s-1)/s for some s≥4/3,then measurement matrix A and linear map A satisfy truncated sparse approximation property of order *** should be pointed out that when Tc=Ф,our conclusion implies that sparse approximation property of order k is weaker than restricted isometry property of order sk.

关键词： truncated norm minimization truncated sparse approximation property restricted isometry property sparse signal recovery low-rank matrix recovery Dantzig selector

Adversarial data splitting for domain generalization

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Science China(Information Sciences) 2024年第5期67卷 28-42页

作者： Xiang gu jian SUN Zongben XU School of Mathematics and Statistics Xi'an Jiaotong University

Domain generalization aims to learn a model that is generalizable to an unseen target domain,which is a fundamental and challenging task in machine learning for out-of-distribution generalization. This paper proposes a novel domain generalization approach that enforces the learned model to be able to generalize well over the train/val subset splitting of the training dataset. This idea is modeled herein as an adversarial data splitting framework, formulated as a min-max optimization problem inspired by the metalearning approach. The min-max optimization problem is solved by iteratively splitting the training dataset into the training and val subsets to maximize the domain shift measured by the objective function and updating the model parameters to enable the model to generalize well from the training subset to the val subset by minimizing the objective function. This adversarial training approach does not assume the known domain labels of the training data; instead, it automatically investigates the “hard” splitting of the train/val subsets to learn the generalizable model. Extensive experimental results using three benchmark datasets demonstrate the superiority of this approach. In addition, we derive a generalization error bound for the theoretical understanding of our proposed approach.

关键词： domain generalization adversarial learning data splitting meta-learning out of distribution

创新意识和创新能力培养中高校考试改革的探索

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山西医科大学学报（基础医学教育版） 2011年第4期13卷 397-400页

作者：李红枝毛建文古宏标黄榕波邢德刚广东药学院基础学院广州510006

当前高校现有考试制度与考试方式严重制约了学生创新意识和创新能力培养和发展,较难为新时期创新型社会的发展输送适应性人才,改革高校考试方式与考试制度势在必行。根据创新意识和创新能力培养的要求,就基础医学学科课程中实施的考核... 详细信息

当前高校现有考试制度与考试方式严重制约了学生创新意识和创新能力培养和发展,较难为新时期创新型社会的发展输送适应性人才,改革高校考试方式与考试制度势在必行。根据创新意识和创新能力培养的要求,就基础医学学科课程中实施的考核目的、考试内容、考试形式以及激励教师从事考试改革等方面进行了总结,探索出一套有利于创新人才培养的考核制度,有效提高了教育教学质量,较好地为经济社会发展提供具有创新能力的人才。

关键词：考试改革创新能力人才培养

THE EIGENVALUE PERTURBATION BOUND FOR ARBITRARY MATRICES

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Journal of Computational Mathematics 2006年第2期24卷 141-148页

作者： wen Li jian-xin Chen School of Mathematical Sciences South China Normal University Guangzhou 510631 China College of Applied Mathematics Guangdong University of Technology Guangzhou 510090 China

In this paper we present some new absolute and relative perturbation bounds for the eigenvalue for arbitrary matrices, which improves some recent results. The eigenvalue inclusion region is also discussed.

关键词： Eigenvalue perturbation bound Jordan canonical form Frobenius norm Spectral norm Inclusion region.

The potential of using blood circular RNA as liquid biopsy biomarker for human diseases

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Protein & Cell 2021年第12期12卷 911-946页

作者： guoxia wen Tong Zhou Wanjun gu State Key Laboratory of Bioelectronics School of Biological Sciences and Medical EngineeringSoutheast UniversityNanjing210096China Department of Physiology and Cell Biology Reno School of MedicineUniversity of NevadaRenoNV89557USA

Circular RNA(circRNA)is a novel class of single-stranded RNAs with a closed loop *** majority of circRNAs are formed by a back-splicing process in pre-mRNA *** expression is dynamically regulated and shows spatiotemporal patterns among cell types,tissues and developmental *** have important biological functions in many physiological processes,and their aberrant expression is implicated in many human *** to their high stability,circRNAs are becoming promising biomarkers in many human diseases,such as cardiovascular diseases,autoimmune diseases and human *** this review,we focus on the translational potential of using human blood circRNAs as liquid biopsy biomarkers for human *** highlight their abundant expression,essential biological functions and significant correlations to human diseases in various components of peripheral blood,including whole blood,blood cells and extracellular *** addition,we summarize the current knowledge of blood circRNA biomarkers for disease diagnosis or prognosis.

关键词： peripheral blood circular RNA liquid biopsy human diseases translational biomarkers

Higher order asymptotic behaviour of partial maxima of random sample from generalized Maxwell distribution under power normalization

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Applied Mathematics(A Journal of Chinese Universities) 2018年第2期33卷 177-187页

作者： HUANG jian-wen WANG jian-jun School of Mathematics and Statistics Southwest University Research Center for Artificial Intelligence & Education Big Data Southwest University

In this article, the higher order asymptotic expansions of cumulative distribution function and probability density function of extremes for generalized Maxwell distribution are established under nonlinear normalization. As corollaries, the convergence rates of the distribu- tion and density of maximum are obtained under nonlinear normalization.

关键词： higher order expansion extreme generalized Maxwell distribution nonlinear normalization

Product Specification Analysis for Modular Product Design Using Big Sales Data

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Chinese Journal of Mechanical Engineering 2023年第1期36卷 19-33页

作者： jian Zhang Bingbing Li Qingjin Peng Peihua gu Department of Mechanical Engineering Shantou UniversityShantou515063China Department of Mechanical Engineering University of ManitobaManitobaR3T 5V6Canada International Institute for Innovative Design and Intelligent Manufacturing of Tianjin University Shaoxing312000China School of Mechanical Engineering Tianjin UniversityTianjin300350China

Big data on product sales are an emerging resource for supporting modular product design to meet diversified customers’requirements of product specification *** better facilitate decision-making of modular product design,correlations among specifications and components originated from customers’conscious and subconscious preferences can be investigated by using big data on product *** study proposes a framework and the associated methods for supporting modular product design decisions based on correlation analysis of product specifications and components using big sales *** correlations of the product specifications are determined by analyzing the collected product sales *** building the relations between the product components and specifications,a matrix for measuring the correlation among product components is formed for component *** rules for supporting the decision making of modular product design are proposed based on the frequency analysis of the specification values per component cluster.A case study of electric vehicles illustrates the application of the proposed method.

关键词： Modular product design Customer preference Product specifications Correlation analysis Big sales data Electric vehicle