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Chinese Annals of Mathematics,Series B 2021年第5期42卷 643-676页

作者： xing lu Tatsien LI School of Mathematics Southeast UniversityNanjing 211189China School of Mathematical Sciences Fudan UniversityShanghai 200433China Shanghai Key Laboratory for Contemporary Applied Mathematic Nonlinear Mathematical Modeling and Methods Laboratory

In this paper the authors first present the definition and some properties of weak solutions to 1-D first order linear hyperbolic systems. Then they show that the constructive method with modular structure originally given in the framework of classical solutions is still very powerful and effective in the framework of weak solutions to prove the exact boundary(null) controllability and the exact boundary observability for first order hyperbolic systems.

关键词： First order linear hyperbolic system Exact boundary controllability Exact boundary observability Constructive method

Exact Boundary Controllability of Weak Solutions for a Kind of First Order Hyperbolic System——the HUM Method

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Chinese Annals of Mathematics,Series B 2022年第1期43卷 1-16页

作者： xing lu Tatsien LI School of Mathematics Southeast UniversityNanjing 211189China School of Mathematical Sciences Fudan UniversityShanghai 200433China Shanghai Key Laboratory for Contemporary Applied Mathematics Fudan University Nonlinear Mathematical Modeling and Methods Laboratory Fudan University

The exact boundary controllability and the exact boundary observability for the 1-D first order linear hyperbolic system were studied by the constructive method in the framework of weak solutions in the work[lu,*** Li,T.T.,Exact boundary con-trollability of weak solutions for a kind of first order hyperbolic system—the constructive method,***.B,42(5),2021,643-676].In this paper,in order to study these problems from the viewpoint of duality,the authors establish a complete the-ory on the HUM method and give its applications to first order hyperbolic ***,a deeper relationship between the controllability and the observability can be ***,at the end of the paper,a comparison will be made between these two methods.

关键词： First order linear hyperbolic system Exact boundary controllability The HUM method

Laser additive manufacturing of laminated bulk metallic glass composite with desired strength-ductility combination

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Journal of Materials Science & Technology 2023年第16期147卷 68-76页

作者： Xiangcheng Cui Weihua Hu xing lu Yunzhuo lu School of Materials Science and Engineering Dalian Jiaotong UniversityDalian 116028China

Introducing ductile crystalline dendrites into a glassy matrix to produce bulk metallic glass composites(BMGCs)is an effective way to improve the poor ductility of bulk metallic glasses(BMGs).However,the presence of soft crystalline phases tends to decrease the strength and causes the strength-ductility ***,relying on the flexible laser additive manufacturing(LAM)technique that allows the composition tailoring of each layer,we successfully fabricate a lamellated Zr-based BMGC constructed by the alternating superimposition of soft and hard *** lamellated BMGC shows an exceptional combination of yield strength(∼1.2 GPa)and ductility(∼5%).Such enhanced strength-ductility synergy is attributed to the asynchronous deformation at two scales,i.e.,inter-laminar and intra-laminar,and the unique dual-scale Ta particles that uniformly distribute on the amorphous *** lamellated structure design motif,enabled by the flexible LAM technology,provides a new window for the development of high-performance *** is also applicable to the synergistic enhancement of strength and plasticity of other brittle metallic materials.

关键词： Bulk metallic glass composite Additive manufacturing Mechanical property Lamellated Strength-ductility synergy

Synthesis and electromagnetic wave absorption properties of Gd-Co ferrite@carbon core-shell structure composites

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Rare Metals 2023年第1期42卷 254-262页

作者： Jing Gao Zhi-Jun Ma Fu-Li Liu xing-Yuan weng School of Mining Liaoning Technical UniversityFuxin123000China

Developing high-performance electromagnetic absorbing materials remains a *** this work,Gd-Co ferrite@carbon core-shell structure composites were synthesized by a two-step hydrothermal *** effects of rare earth Gd doping amount on the microstructure and electromagnetic wave absorption properties of cobalt ferrite@carbon composites were mainly *** results show that an appropriate amount of Gd doping can refine the crystal grain size of cobalt ferrite@carbon ***,when the doping amount of Gd exceeds the solid solubility threshold,the secondary phase GdFeO_(3)will be generated and the grain size will *** the doping amount of Gd is x=0.04,the reflection loss(RL) of the CoFe_(1.96)Gd_(0.04)O_(4)@C composites reaches the minimum value of -9.26 dB at the absorption layer thickness of 2.0 mm and a frequency of 13.67 GHz,and the effective absorption band(EAB) is 5.01 GHz(10.95-15.96 GHz).Compared with the CoFe_(2)O_(4)@C composites,the RL of the CoFe_(1.96)Gd_(0.04)O_(4)@C composites is increased by 79.35%,and the EAB is broadened by 3.51%.Gd ions enhance the dielectric loss through the grain size effect,and the increase of magnetocrystalline anisotropy enhances the magnetic *** CoFe_(1.96)Gd_(0.04)O_(4)@C composites have excellent impedance matching,which relies on the strong magnetic loss of ferrite,the interface polarization,and dipole polarization formed by the carbon shell to attenuate electromagnetic waves.

关键词： Rare earth Gd Cobalt ferrite Core-shell structure composites Electromagnetic wave absorption

QoS Guaranteed Pre-Pushing Scheme in Peer-Assisted Streaming Network

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China Communications 2014年第A2期11卷 111-117页

作者： LIN Fuhong lu xing School of Computer and Communication Engineering University of Science and Technology Beijing Beijing 100083 P. R. China School of Science Beijing Jiaotong University Beijing 100044 P. R. China

In peer-assisted streaming network, service provider needs to pre-pushing resources to some users for caching. This scheme can increase the resource availability. In traditional strategy, in order to guarantee the user＇s quality of service （QoS）, the pre-pushing action can only start at the time point that the certain user has not used the computer for more than 20 minutes. If the user comes back, the pre-pushing action will be stopped. We claim that this is not an efficient scheme. In this paper, we propose a novel pre-pushing scheme to improve the pre-pushing efficiency, while meeting the user＇s QoS requirements. The basic idea is using the user＇s available bandwidth as much as possible in the condition of meeting the user＇s QoS requirements. Then we design an available bandwidth calculating strategy. The numerical simulation demonstrates that our proposed scheme outperforms the traditional one.

关键词： peer-assisted streaming network downlink bandwidth pre-pushing available bandwidth

A porous high-entropy alloy for high-efficient oxygen evolution reaction

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Rare Metals 2023年第7期42卷 2174-2181页

作者： Wei Wang Yun-Zhuo lu xing lu School of Materials Science and Engineering Dalian Jiaotong UniversityDalian116028China

Oxygen evolution reaction(OER)plays a crucial role in regulating the process of hydrogen production from water splitting where an expeditious,stable and low-cost electrocatalyst is urgently *** employing a facile strategy of selective phase dissolution,this dissertation attempts to illuminate the successful preparation of a porous AlCoCrFeNi high-entropy alloy(SPD-48 h).

关键词： alloy entropy evolution

Numerical Modeling of the Compression Process of Elastic Open-cell Foams

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Chinese Journal of Aeronautics 2007年第3期20卷 215-222页

作者： ZHANG Jia-lei lu Zi-xing Institute of Solid Mechanics Beijing University of Aeronautics and Astronautics Beijing 100083 China

The random models of open-cell foams that can reflect the actual cell geometrical properties are constructed with the Voronoi technique. The compression process of elastic open-cell foams is simulated with the nonlinear calculation module of finite element analysis program. In order to get the general results applicable to this kind of materials, the dimensionless compressive stress is used and the stress-strain curves of foam models with different geometrical properties are obtained. Then, the influences of open-cell geometrical properties, including the shape of strut cross section, relative density and cell shape irregularity, on the compressive nonlinear mechani- cal performance are analyzed. In addition, the numerical results are compared with the predicted results of cubic staggering model. Nu- merical results indicate that the simulated results reflect the compressive process of foams quite well and the geometrical properties of cell have significant influences on the nonlinear mechanical behavior of foams.

关键词： Voronoi technique open-cell foam nonlinear compressive stress

The heading-date gene Ghd7 inhibits seed germination by modulating the balance between abscisic acid and gibberellins

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The Crop Journal 2021年第2期9卷 297-304页

作者： Yong Hu Song Song Xiaoyu weng Aiqing You Yongzhong xing Hubei Key Laboratory of Food Crop Germplasm and Genetic Improvement Food Crops Research InstituteHubei Academy of Agricultural SciencesWuhan 430064HubeiChina National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research(Wuhan) Huazhong Agricultural UniversityWuhan 430070HubeiChina

Seed dormancy of cultivated rice was largely weakened during the progress of *** timing and uniformity of seed germination are important for rapid seedling establishment and highyield *** the present study,we found that the heading-date gene Ghd7 acted as a negative regulator of germination.A mutant of ghd7 showed low sensitivity to exogenous ABA treatment during seed *** investigation revealed reduced accumulation of ABA in mature ghd7 seeds as a consequence of dampened expression of OsNCED ***,elevated GA_(3) level was detected in seeds of ghd7 mutant during imbibition course,which was attributed to the induction of genes responsible for the synthesis pathways of bioactive ***,Ghd7 inhibits seed germination by increasing the ABA/GA_(3) *** revealing pleiotropic effects of Ghd7,our results indicate its role in linking seed germination to growth-phase transition in rice,which would enrich the theoretical basis for future breeding practices.

关键词： Ghd7 Seed germination Abscisic acid Gibberellins ABA/GA_(3)ratio

General construction of revocable identity-based fully homomorphic signature

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Science China(Information Sciences) 2020年第3期63卷 266-271页

作者： Congge XIE Jian weng Wei lu Lin HOU College of Information Science and Technology Jinan University School of Data and Computer Science Sun Yat-sen University

Dear editor,Fully homomorphic signature (FHS) is a cryptographic primitive and allows anyone to conduct any computations over signatures and generate a signature which, when verified, matches the calculated value of the computational run on the messages. An identity-based fully homomorphic signature (IBFHS) extended from an FHS can avoid

关键词： General construction of revocable identity-based fully homomorphic signature

Current development in quantitative phase-field modeling of solidification

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Journal of Iron and Steel Research International 2017年第9期24卷 865-878页

作者： Xiang-lei Dong Hui xing Kang-rong weng Hong-liang Zhao College of Materials Science and Engineering Zhengzhou UniversityZhengzhou 450001HenanChina Shaanxi Key Laboratory for Condensed Matter Structure and Properties Northwestern Polytechnical UniversityXi'an 710129ShaanxiChina State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi'an 710072ShaanxiChina

The quantitative phase-field simulations were reviewed on the processes of solidification of pure metals and *** quantitative phase-field equations were treated in a diffuse thin-interface limit,which enabled the quantitative links between interface dynamics and model parameters in the quasi-equilibrium *** a result,the quantitative modeling is more effective in dealing with microstructural pattern formation in the large scale simulations without any spurious kinetic *** development of the quantitative phase-field models in modeling the formation of microstructures such as dendritic structures,eutectic lamellas,seaweed morphologies,and grain boundaries in different solidified conditions was also reviewed with the purpose of guiding to find the new prospect of applications in the quantitative phase-field simulations.

关键词： Phase-field modeling Liquid-solid interface Solidification Dendritic growth Microstructural formation