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Microstructure and Magnetic Anisotropy of FeCoNbB Films

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Chinese Journal of Aeronautics 2011年第6期24卷 823-828页

作者： YANG Youran WANG yanyan LI Ying BI Xiaofang Key Laboratory of Aerospace Materials and Performance （Ministry of Education） School of Materials Science and Engineering Beihang University Beijing 100191 China

Effect of Nb contents on microstructure and magnetic properties of FeCoNbB films has been studied. X-ray diffraction （XRD） analysis reveals that Nb plays a role in refining grain and in facilitating formation of amorphous structure. When Nb content is more than 8 at%, the films transform from crystalline to amorphous structure, accompanied by variations in magnetic properties. An unusual out-of-plane anisotropy component is consequently observed. It can be suggested that the anisotropy induced by increasing Nb contents be attributed to stress-related magnetoelastic anisotropy. The undesirable anisotropy is greatly reduced by thermal annealing, reducing film thicknesses or applying an external magnetic field together with si addition.

关键词： FeCoNbB films magnetic anisotropy Nb contents annealing film thickness

Cohomology of Moduli Space of Cubic Fourfolds Ⅰ

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Acta Mathematica sinica,English Series 2023年第5期39卷 773-798页

作者： Fei si Shanghai Research Center For Mathematical Science Shanghai 200433P.R.China

In this paper we compute the cohomology of moduli space of cubic fourfolds with ADE type singularities relying on Kirwan’s blowup and Laza’s GIT construction. More precisely, we obtain the Betti numbers of Kirwan’s resolution of the moduli space. Furthermore, by applying decomposition theorem we obtain the Betti numbers of the intersection cohomology of Baily-Borel compactification of the moduli space.

关键词： Cubic fourfold Moduli space Cohomology

基于SBAS-InSAR和光学遥感的天津市北部山区潜在滑坡识别研究

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灾害学 2025年第1期40卷 30-35页

作者：王勇邢振涛李锁闫勇司甜天津城建大学地质与测绘学院天津300384 天津市地质工程勘测设计院有限公司天津300191

以天津市北部山区为研究对象,开展潜在滑坡识别研究,利用差分干涉测量短基线集时序分析技术(SBAS-InSAR)处理2018-01—2022-08的56景Sentinel-1A数据,并结合2018—2022年的Landsat8光学遥感影像,分析形变与光学遥感影像特征以及NDVI,筛... 详细信息

以天津市北部山区为研究对象,开展潜在滑坡识别研究,利用差分干涉测量短基线集时序分析技术(SBAS-InSAR)处理2018-01—2022-08的56景Sentinel-1A数据,并结合2018—2022年的Landsat8光学遥感影像,分析形变与光学遥感影像特征以及NDVI,筛选出潜在滑坡区域。研究结果表明:基于SBAS-InSAR技术识别的天津北部山区的形变较大区域有20处,使用光学遥感影像结合各发育环境要素进行处理确定的区域有19处,其中5处经两种技术确认为滑坡隐患,通过对该5处沉降信息进行识别分析,该5处区域最大年形变速率可达-12 mm/a,需要进行重点监测预警,使用两种技术结合对滑坡隐患区域进行识别可以有效地提高识别准确度,为天津北部山区灾害监测提供新的方式。

关键词：潜在滑坡 SBAS-InSAR 光学遥感影像天津市北部山区

机器学习在智能反射面辅助的通信系统中的应用综述

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北京工业大学学报 2025年第1期51卷 87-99页

作者：司鹏搏李双缘刘畅李萌北京工业大学信息学部北京100124 先进信息网络北京实验室北京100124

智能反射面(intelligent reflecting surfaces,IRS)可以通过大量低成本的无源反射元件巧妙地调整信号反射,从而动态改变无线信道,提高通信性能,目前已成为无线通信研究的焦点。然而,由于IRS的加入,整个通信系统变得更加复杂,系统的动态... 详细信息

智能反射面(intelligent reflecting surfaces,IRS)可以通过大量低成本的无源反射元件巧妙地调整信号反射,从而动态改变无线信道,提高通信性能,目前已成为无线通信研究的焦点。然而,由于IRS的加入,整个通信系统变得更加复杂,系统的动态性也更高,使通信系统面临着许多新的挑战。机器学习(machine learning,ML)具有很强的数据处理与自适应能力,能够不断适应变化的环境和需求,可以很好地应对通信系统中的许多挑战。因此,使用ML解决IRS辅助的通信系统中的问题,已经成为当前研究的重点。基于此,对ML在IRS系统中的应用进行了系统性的概述,从IRS辅助的通信系统中存在的问题入手,分别从反射因子的设计与优化、信道处理与建模、资源分配和管理、安全性增强4个方面对ML在IRS系统中的应用进行阐述和分析,并讨论了将ML应用在IRS系统中的优势及未来的发展趋势与挑战。

关键词：智能反射面(intelligent reflecting surfaces,IRS) 无线通信反射因子信道资源分配通信安全机器学习(machine learning,ML)

Teaching of pharmacology in Universiti Malaya and the other medical schools in Malaysia - a historical perspective

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Acta Pharmacologica sinica 2004年第9期25卷 107-117页

作者： si Mui siM 50603 Kuala Lumpur Department of Pharmacology Faculty of Medicine Malaysia University of Malaya

Traditional pharmacology teaching has focused more on drug instead of therapeutics, such that although pharmacological knowledge is acquired, practical skills in prescribing remain weak. In Malaysia many new medical schools (both public and private) have been set up in the last 12 years due to a change in government policy, resulting in a wide spectrum of medical curricula. Universiti Malaya (UM) being the oldest medical school in

关键词： pharmacology teaching basic sciences Malaysian medical schools integrated curriculum problem-based learning

Efects of diferent casting mould cooling rates on microstructure and properties of sand-cast Al-7.5si-4Cu alloy

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China Foundry 2013年第6期10卷 396-400页

作者： Liu Guanglei si Naichao Sun Shaochun Wu Qinfang School of Materials Science and Engineering Jiangsu University Suzhou Mingzhi Technology Ltd.

In this work, AI-7.5si-4Cu alloy melt modified by AI-10Sr, RE and AI-5-13-B master alloys was poured into multi-step moulds made from three moulding sands, including quartz, alumina and chromite, to investigate comparatively the effects of different cooling rates of the casting mould on the alloy＇s microstructures and mechanical properties. The results show that with an increase in wall thickness, the cooling rate decreases, the dendrite arm spacing （DAS） increases significantly and the mechanical properties decrease steadily. The elongation is more sensitive to the cooling rate than the tensile strength. No obvious trend of the effect of wall thickness on hardness of the alloy was found. When the cooling rate is at its greatest, the microstructures and mechanical properties are the best when using chromite sand. The improvement of the properties is mainly attributed to the decrease of the DAS, the grain refinement and the metamorphic effect. Each of the three has a strong impact on the microstructures. Furthermore, a series of fitting models was established based on the data of the DAS to predict the mechanical properties of the multivariate sand-cast AI-7.5si-4Cu alloy,

关键词： Al-7.5si-4Cu alloy cooling rate properties and microstructure fitting analysis

L2, 1-Norm Regularized Matrix Completion for Attack Detection in Collaborative Filtering Recommender Systems

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Chinese Journal of Electronics 2019年第5期28卷 906-915页

作者： si Mingdan LI Qingshan School of Computer Science and Technology Xidian University

Collaborative filtering recommender systems(CFRSs) are known to be highly vulnerable to profile injection attacks, in which malicious users insert fake profiles into the rating database in order to bias the systems' output, since their openness, and attack detection is still a challenging problem in CFRSs. In order to provide more accurate recommendations, many schemas have been proposed to detect such shilling ***, almost all of them are proposed to detect one or several specific attack types, and few of them can handle hybrid attack types, which usually happen in practice. With this problem in mind, we propose a novel L2, 1-norm regularized matrix completion incorporating prior information(LRMCPI) model to detect shilling attacks by combining matrix completion and L2, *** proposed LRMCPI formalizes the attack detection problem as a missing value estimation problem, and it is appropriate because the user-item rating matrix is approximately low-rank and attack profiles could be considered as structural noise. The proposed LRMCPI model not only can better recover the rating matrix using correct rating value but also can detect the positions where the attackers are injected. We evaluate our model on three well-known data sets with different density and the experimental results show that our model outperforms baseline algorithms in both single and hybrid attack types.

关键词： Profile injection attacks Shilling attacks Attack detection L2,1-norm Matrix completion

Epigenetic regulation of plant immunity:from chromatin codes to plant disease resistance

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aBIOTECH 2023年第2期4卷 124-139页

作者： si-si Xie Cheng-Guo Duan Shanghai Center for Plant Stress Biology and CAS Center for Excellence in Molecular Plant Sciences Chinese Academy of SciencesShanghai 200032China University of the Chinese Academy of Sciences Beijing 100049China

Facing a deteriorating natural environment and an increasing serious food crisis,bioengineering-based breeding is increasing in *** defend against pathogen infection,plants have evolved multiple defense mechanisms,including pathogen-associated molecular pattern(PAMP)-triggered immunity(PTI)and effector-triggered immunity(ETI).A complex regulatory network acts downstream of these PTI and ETI pathways,including hormone signal transduction and transcriptional *** recent years,increasing lines of evidence show that epigenetic factors act,as key regulators involved in the transcriptional reprogramming,to modulate plant immune ***,we summarize current progress on the regulatory mechanism of DNA methylation and histone modifications in plant defense *** addition,we also discuss the application of epigenetic mechanism-based resistance strategies in plant disease breeding.

关键词： Histone modification DNA methylation Transcriptional reprogramming Plant immunity Disease resistance

Condensed Galerkin element of degree m for first-order initial-value problem with O(h^(2m+2))super-convergent nodal solutions

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Applied Mathematics and Mechanics(English Edition) 2022年第4期43卷 603-614页

作者： si YUAN Quan YUAN Department of Civil Engineering Key Laboratory of Civil Engineering Safety and Durability of China Education MinistryTsinghua UniversityBeijing 100084China

A new type of Galerkin finite element for first-order initial-value problems(IVPs)is *** the trial and test functions employ the same m-degreed *** adjoint equation is used to eliminate one degree of freedom(DOF)from the test function,and then the so-called condensed test function and its consequent condensed Galerkin element are *** is mathematically proved and numerically verified that the condensed element produces the super-convergent nodal solutions of O(h^(2m+2)),which is equivalent to the order of accuracy by the conventional element of degree m+*** related properties are addressed,and typical numerical examples of both linear and nonlinear IVPs of both a single equation and a system of equations are presented to show the validity and effectiveness of the proposed element.

关键词： Galerkin method finite element method(FEM) condensed element superconvergence adjoint operator initial-value problem(IVP)