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Fracture Analysis in Orthotropic Thermoelasticity Using Extended Finite Element Method

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Advances in Applied Mathematics and Mechanics 2015年第6期7卷 780-795页

作者： Honggang jia Yufeng nie Junlin Li Department of Applied Mathematics School of ScienceNorthwestern Polytechnical UniversityXi’an 710129China Taiyuan University of Science and Technology School of Applied ScienceTaiyuan 030024China

In this paper,a method for extracting stress intensity factors(SIFs)in orthotropic thermoelasticity fracture by the extended finite element method(XFEM)and interaction integral method is *** proposed method is utilized in linear elastic crack *** numerical results of the SIFs are presented and compared with those obtained using boundary element method(BEM).The good accordance among these two methods proves the applicability of the proposed approach and conforms its capability of efficiently extracting thermoelasticity fracture parameters in orthotropic material.

关键词： Fracture orthotropic thermoelasticity interaction integral method XFEM

Cross-Domain Authentication Scheme Based on Blockchain and Consistent Hash Algorithm for System-Wide Information Management

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Computers, Materials & Continua 2023年第11期77卷 1467-1488页

作者： Lizhe Zhang Yongqiang Huang jia nie Kenian Wang Key Laboratory of Civil Aircraft Airworthiness Technology Civil Aviation University of ChinaTianjin300000China School of Safety Science and Engineering Civil Aviation University of ChinaTianjin300000China

System-wide information management(SWIM)is a complex distributed information transfer and sharing system for the next generation of Air Transportation System(ATS).In response to the growing volume of civil aviation air operations,users accessing different authentication domains in the SWIM system have problems with the validity,security,and privacy of SWIM-shared *** order to solve these problems,this paper proposes a SWIM crossdomain authentication scheme based on a consistent hashing algorithm on consortium blockchain and designs a blockchain certificate format for SWIM cross-domain *** scheme uses a consistent hash algorithm with virtual nodes in combination with a cluster of authentication centers in the SWIM consortium blockchain architecture to synchronize the user’s authentication mapping relationships between authentication *** virtual authentication nodes are mapped separately using different services provided by SWIM to guarantee the partitioning of the consistent hash ring on the consortium *** to the dynamic change of user’s authentication requests,the nodes of virtual service authentication can be added and deleted to realize the dynamic load balancing of cross-domain authentication of different *** analysis shows that this protocol can resist network attacks such as man-in-the-middle attacks,replay attacks,and Sybil *** show that this scheme can reduce the redundant authentication operations of identity information and solve the problems of traditional cross-domain authentication with single-point collapse,difficulty in expansion,and uneven *** the same time,it has better security of information storage and can realize the cross-domain authentication requirements of SWIM users with low communication costs and system *** System-wide information management(SWIM);consortium blockchain;consistent hash;cross-domain authentication;load balancing.

关键词： System-wide information management(SWIM) consortium blockchain consistent hash cross-domain authentication load balancing

Low loss Z-type Hexaferrites with Bi2O3 Additives for Ultra-high Frequency Antenna Applications

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Journal of Wuhan University of Technology(Materials Science) 2019年第5期34卷 1037-1042页

作者： GUO Yongqiang nie yan School of Optical and Electronic Information Huazhong University of Science and Technology

The Z-type ferrites of nominal composition Ba3Co2 Fe24O41+x wt% Bi2O3, where x=0.25, 0.5, 1.0, 1.5, 2.0, were prepared by conventional ceramic processes. The influence of Bi2O3 content on the bulk densities, microstructures, magnetic and dielectric properties of Z-type ferrite samples were systematically examined so as to obtain materials with low magnetic and dielectric loss tangent over a frequency ranging from 600 to 800 MHz. The experimental results showed that addition of Bi2O3 lowered the sintering temperature(1 020 ℃) and then reduced the average grain size(2.68×10^8 Ω·cm) dramatically, which consequently decreased the magnetic and dielectric loss. Additionally, the low loss factors were observed at the Bi2O3 content x = 1.0, i e, tan δμ/μ’=0.013 and tan δε/ε’= 0.001 at 800 MHz, and such materials could be used for antennas miniaturization from 600 to 800 MHz.

关键词： low loss Z-type ferrites grain size antennas

A Finite-Difference Approximation for the Oneand Two-Dimensional Tempered Fractional Laplacian

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Communications on Applied Mathematics and Computation 2020年第1期2卷 129-145页

作者： Yaoqiang yan Weihua Deng Daxin nie School of Mathematics and Statistics Gansu Key Laboratory of Applied Mathematics and Complex SystemsLanzhou UniversityLanzhou 730000China

This paper provides a finite-difference discretization for the one-and two-dimensional tempered fractional Laplacian and solves the tempered fractional Poisson equation with homogeneous Dirichlet boundary *** main ideas are to,respectively,use linear and quadratic interpolations to approximate the singularity and non-singularity of the one-dimensional tempered fractional Laplacian and bilinear and biquadratic interpolations to the two-dimensional tempered fractional ***,we give the truncation errors and prove the *** experiments verify the convergence rates of the order O(h^2−2s).

关键词： Tempered fractional Laplacian Finite-diff erence scheme Linear and quadratic interpolations Bilinear and biquadratic interpolations Convergence rates

野生二粒小麦AP2家族基因鉴定与表达模式分析

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麦类作物学报 2025年第1期45卷 24-36页

作者：刘涛曹启彬卫科旭张艳聂小军童维西北农林科技大学农学院陕西杨凌712100

AP2转录因子在植物信号转导、生长发育和胁迫响应方面发挥着重要作用。为探索AP2转录因子在野生二粒小麦中的分子特征,基于野生二粒小麦基因组信息,采用Blast和Hmmer进行AP2家族成员鉴定,对鉴定到的成员进行蛋白质理化性质、亚细胞定位... 详细信息

AP2转录因子在植物信号转导、生长发育和胁迫响应方面发挥着重要作用。为探索AP2转录因子在野生二粒小麦中的分子特征,基于野生二粒小麦基因组信息,采用Blast和Hmmer进行AP2家族成员鉴定,对鉴定到的成员进行蛋白质理化性质、亚细胞定位、系统进化树、保守结构域、基因扩增、顺式作用元件、密码子偏好性、表达模式和遗传多样性分析。结果表明,在野生二粒小麦中共鉴定到265个AP2基因,主要定位在细胞核和叶绿体中。根据系统进化树将其分为3个亚族,各亚族之间的保守结构域和基因结构存在保守性与多样性。AP2含有多个与生长发育和非生物胁迫相关的顺式作用元件。AP2基因的密码子偏好性可能受到压力选择作用。从AP2基因的表达模式看,该家族成员可能发生了亚功能化,且对盐胁迫响应有重要作用。通过对不同小麦群体中核酸多样性和分化指数分析,AP2基因部分成员在野生二粒小麦中具有较高的遗传多样性。

关键词：野生二粒小麦 AP2基因进化分析表达模式遗传多样性

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Superplastic behavior of a powder metallurgy superalloy during isothermal compression

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Journal of Materials Science & Technology 2019年第11期35卷 2591-2599页

作者： Liming Tan Yunping Li Feng Liu yan nie Liangjiang State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China Powder Metallurgy Research Institute Central South UniversityChangsha 410083China High Temperature Materials Research Institute Central South UniversityChangsha 410083China Yuanmeng Precision Technology(Shenzhen)Institute Shenzhen 518000China

In this work,the flow behaviors and microstructure evolution of a powder metallurgy nickel-based superalloy during superplastic compression is *** on the strain rate sensitivity m determined by flow data,superplastic region is estimated at relatively low temperature and strain rate domains,specifically around 1000℃/10^-3s^-***,the cylinder specimens are isothermally compressed at 1000℃/10^-3s^-1 and 1025℃/10^-3s^-1 with different strains,to exam the superplasticity and related *** experimental results indicate that the accumulated dislocations are mainly annihilated by dynamic recovery and dynamic recrystallization(DRX),and the grain boundary sliding(GBS)contributes to the total strain during superplastic compression as *** addition,the cavities and cracks at triple junctions or interfaces between matrix and second phase particle have not been detected,which is different from superplastic tensile deformation.

关键词： Nickel-based superalloy Superplastic deformation Dynamic recrystallization Grain boundary sliding Hot compression

Cyclic Beam Direction of Arrival Estimation Method for Ship Propeller Noise

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Journal of Ocean University of China 2024年第4期23卷 883-896页

作者： ZHANG Xiaowei nie Weihang XU Ji yan Yonghong The Key Laboratory of Speech Acoustics and Content Understanding Institute of AcousticsChinese Academy of SciencesBeijing 100190China The Key Laboratory of Speech Acoustics and Content Understanding Institute of AcousticsUniversity of Chinese Academy of SciencesBeijing 100049China The State Key Laboratory of Acoustics Institute of AcousticsChinese Academy of SciencesBeijing 100190China

In underwater acoustic applications,the conventional cyclic direction of arrival algorithm faces challenges,including a low signal-to-noise ratio and high bandwidth when compared with modulated *** response to these issues,this paper introduces a novel,robust,and broadband cyclic beamforming *** proposed method substitutes the conventional cyclic covariance matrix with the variance of the cyclic covariance matrix as its primary *** that the same frequency band shares a common steering vector,the new algorithm achieves superior detection performance for targets with specific modulation frequencies while suppressing interference signals and background *** results demonstrate a significant enhancement in the directibity index by 81%and 181%when compared with the traditional Capon beamforming algorithm and the traditional extended wideband spectral cyclic MUSIC(EWSCM)algorithm,***,the proposed algorithm substantially reduces computational complexity to 1/40th of that of the EWSCM algorithm,employing frequency band statistical averaging and covariance matrix variance.

关键词： cyclostationarity direction of arrival extended wideband spectral cyclic music cyclic covariance matrix

A Test of U-type for Goodness-of-fit in Regression Models Through Martingale Difference Divergence

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Acta Mathematicae Applicatae Sinica 2024年第4期40卷 979-1000页

作者： Kai XU yan-qin nie Dao-jiang HE School of Mathematics and Statistics Anhui Normal UniversityWuhu 241002China

Based on the martingale difference divergence,a recently proposed metric for quantifying conditional mean dependence,we introduce a consistent test of U-type for the goodness-of-fit of linear models under conditional mean ***,our test allows heteroscedastic regression models without imposing any condition on the distribution of the error,utilizes effectively important information contained in the distance of the vector of covariates,has a simple form,is easy to implement,and is free of the subjective choice of ***,our mathematical analysis is of own interest since it does not take advantage of the empirical process theory and provides some insights on the asymptotic behavior of U-statistic in the framework of model *** asymptotic null distribution of the proposed test statistic is derived and its asymptotic power behavior against fixed alternatives and local alternatives converging to the null at the parametric rate is also *** particular,we show that its asymptotic null distribution is very different from that obtained for the true error and their differences are interestingly related to the form expression for the estimated parameter vector embodied in regression function and a martingale difference divergence *** the asymptotic null distribution of the test statistic depends on data generating process,we propose a wild bootstrap scheme to approximate its null *** consistency of the bootstrap scheme is *** studies are undertaken to show the good performance of the new test.

关键词： bootstrap goodness-of-fit test linear mean regression martingale difference divergence martingale difference divergence matrix

Cryptomining Malware Detection Based on Edge Computing-Oriented Multi-Modal Features Deep Learning

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China Communications 2022年第2期19卷 174-185页

作者： Wenjuan Lian Guoqing nie yanyan Kang Bin jia yang Zhang College of Computer Science&Engineering Shandong University of Science and TechnologyQingdaoShandong 266590China College of Foreign Languages Shandong University of Science and TechnologyQingdaoShandong 266590China

In recent years,with the increase in the price of cryptocurrencies,the number of malicious cryptomining software has increased *** their powerful spreading ability,cryptomining malware can unknowingly occupy our resources,harm our interests,and damage more legitimate ***,although current traditional rule-based malware detection methods have a low false alarm rate,they have a relatively low detection rate when faced with a large volume of emerging *** though common machine learning-based or deep learning-based methods have certain ability to learn and detect unknown malware,the characteristics they learn are single and independent,and cannot be learned *** at the above problems,we propose a deep learning model with multi-input of multi-modal features,which can simultaneously accept digital features and image features on different *** model in turn includes parallel learning of three sub-models and ensemble learning of another specific *** four sub-models can be processed in parallel on different devices and can be further applied to edge computing *** model can adaptively learn multi-modal features and output prediction *** detection rate of our model is as high as 97.01%and the false alarm rate is only 0.63%.The experimental results prove the advantage and effectiveness of the proposed method.

关键词： cryptomining malware multi-modal ensemble learning deep learning edge computing