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Science China Mathematics 2008年第12期51卷 2205-2216页

作者： jia ZhongXiao WANG zhen Department of Mathematical Sciences Tsinghua UniversityBeijing 100084China

The inexact Rayleigh quotient iteration (RQI) is used for computing the smallest eigenpair of a large Hermitian matrix. Under certain condition, the method was proved to converge quadratically in literature. However, it is shown in this paper that under the original given condition the inexact RQI may not quadratically converge to the desired eigenpair and even may misconverge to some other undesired eigenpair. A new condition, called the uniform positiveness condition, is given that can fix misconvergence problem and ensure the quadratic convergence of the inexact RQI. An alternative to the inexact RQI is the Jacobi-Davidson (JD) method without subspace acceleration. A new proof of its linear convergence is presented and a sharper bound is established in the paper. All the results are verified and analyzed by numerical experiments.

关键词： eigenvalue eigenvector large Hermite matrix inexact RQI simplified JD convergence misconvergence the uniform positiveness condition 65F15

Electrocatalytic oxygen reduction performances of surface Ag granular packs electrodeposited from dual-phase Ag_(35.5)Zn_(64.5) precursor alloys by triangle wave potential cycling

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Rare Metals 2021年第12期40卷 3531-3542页

作者： jia-Yu Luo Piao-Piao Han zhen-Hua Dan Tao Tang Feng-Xiang Qin Hui Chang Lian zhou College of Materials Science and Engineering and Tech Institute for Advanced Materials Nanjing Tech UniversityNanjing 210009China State Key Laboratory of Advanced Metals and Materials University of Science and Technology BeijingBeijing 110083China School of Materials Science and Engineering Nanjing University of Science and TechnologyNanjing 210094China

Surface Ag granular packs(SAgPs) have been fabricated from dual-phase Ag_(35.5)Zn_(64.5) precursor alloy consisting of both e and c phases by using a facile one-step triangle wave potential cycling in 0.5 mol·L^(-1) *** the continuous potential cyclic sweeping, the c phases preferentially dissolve during the anodic scan and dominant reduction reactions of Ag cations lead to redeposition and accumulation of Ag atoms together to form SAg Ps during cathodic scan. The e phases stay inactive to form a continuous skeleton in the inner regions. SAg Ps with an average particle size of 94-129 nm can be obtained at scan rates of 25, 50 and 100 mV·s^(-1) for 100 triangle wave potential cycles. SAgPs formed at a scan rate of 50 mV·s^(-1) exhibit superior oxygen reduction reaction performances with the onset potential of 0.93 V, half-wave potential of 0.72 V and an electron transfer number of *** above-mentioned SAgPs have superior stabilities as ORR catalysts.

关键词： Surface Ag granular packs Dual-phase Ag_(35.5)Zn_(64.5)precursor alloy Triangle wave potential cycling Oxygen reduction reaction catalysts Selective dissolution Intermetallic phases

Deaggregation Behavior of the Phenol Derivatives

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Chinese Journal of Chemistry 2005年第11期23卷 1552-1560页

作者： CHEN, jian YANG, Hui SHEN, zheng-Wu zhou, Xiu-jia YANG, Fan JI, Guo-zhen Shanghai Institute of Organic Chemistry Chinese Academy of Sciences Shanghai 200032 China Shanghai University of Traditional Chinese Medicine Shanghai 201203 China

Aggregation and deaggregation behaviors of the phenol derivatives with a branched hydrocarbon chain have been studied in the CH3OH and buffer solution. Combination with the aggregation number measurement and the cell adhesion experiment, the structure effect on the deaggregating abilities of the target molecules are discussed. The results indicate that 2-phytyl-4-methoxylphenol （11） is the most effective deaggregator in the system studied.

关键词： phenol derivative aggregation deaggregation aggregation number cell adhesion

Reversibly photochromic wood constructed by depositing microencapsulated/polydimethylsiloxane composite coating

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Journal of Forestry Research 2022年第4期33卷 1409-1418页

作者： zhen jia Wenhui Bao Chengyun Tao Wenlong Song School of Mechanical and Electrical Engineering Northeast Forestry UniversityHarbin 150040People’s Republic of China School of Civil Engineering Harbin UniversityHarbin 150086People’s Republic of China

Photochromic wood was fabricated by coating microencapsulated photochromic material(MP)/polydimethylsiloxane composites onto wood using a simple drop-coating ***-melamine–formaldehyde resin was used to microencapsulate the photochromic material(PM)via in situ *** concentration of the MP affected the photochromic property of the wood *** total color change(ΔE*)reached 82.2 when the concentration of the composite coating is 8%.Adhesion tests confirmed that the composite coating adhered firmly to the *** method is potentially useful for the production of functional wooden products,such as anti-counterfeiting materials and aesthetic wood.

关键词： Wood Photochromism Microencapsulation Urea-melamine–formaldehyde resin Drop-coating method

A TVD SCHEME FOR INCOMPRESSIBLE FLOW COUPLED WITH DIFFERENT TURBULENCE MODLES ON A GROUND-MOUNTED SQUARE-RIB FLOW

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Journal of Hydrodynamics 2007年第6期19卷 743-750页

作者： WANG jia-song HUANG zhen School of Mechanical Engineering Shanghai Jiaotong University Shanghai 200240 China

A finite-difference Total Variation Diminishing （TVD） numerical simulation model for coupling the Reynolds Averaged Navier-Stokes （RANS） equations, pressure-relative continuity equation and various k-εturbulence models was developed to solve the incompressible flow based on the pseudo-compressibility method. The hyperbolicity of all these equations was studied and the discretization of the fully coupling equations with all the primal variables and source terms were made in this article. Numerical simulation for modeling the flow around a ground-mounted square rib was implemented and validated by comparing with the published wind tunnel experimental data. It is shown that such a numerical simulation method with a proper turbulence model has a very good accuracy to simulate the flow around a surface-mounted rib. It is concluded that the Renormalization Group （RNG） and Chen-Kim k-εturbulence models have much better ability to predict the characteristics of the vortex structure and flow separation than the standard k-εmodel.

关键词： Total Variation Diminishing (TVD) scheme Reynolds Averaged Navier-Stokes (RANS) turbulence models,square rib pseudo-compressibility method

Blind adaptive identification and equalization using bias-compensated NLMS methods

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Science China(Information Sciences) 2022年第5期65卷 184-195页

作者： zhen ZHANG Lijuan jia Ran TAO Yue WANG School of Information and Electronics Beijing Institute of Technology

In this paper, two new blind adaptive identification and equalization algorithms based on second-order statistics are proposed. We consider a practical case where the noise statistics of each transmission channel is unknown. Resorting to the technique of antennas array, a single-input double-output channel can be obtained. We further convert the problem of blind identification into an errors-in-variables(EIV)parameter estimation problem, then we apply the normalized least-mean squares(NLMS) algorithms to tackle the problem. To improve the performance of the NLMS algorithms, we also develop a variable stepsize NLMS(VSS-NLMS) algorithm that ensures the stability of the algorithm and faster convergence speed at the beginning of the iterations process. Under various practical scenarios, noise affects transmission channels;it is necessary to estimate the variance and remove the bias. By modifying the cost function, we present a bias-compensated NLMS(BC-NLMS) algorithm and a bias-compensated NLMS algorithm with variable step-size(BC-VSS-NLMS) to eliminate the bias. The proposed algorithms estimate the variances of the noise online, and therefore, the noise-induced bias can be removed. The estimate of the channel characteristics is available for equalization. Simulation results are presented to demonstrate the performance of the proposed algorithms.

关键词： blind adaptive identification equalization normalized least mean squares algorithm bias compensation errors-in-variables

Fatty liver diseases, mechanisms, and potential therapeutic plant medicines

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Chinese Journal of Natural Medicines 2020年第3期18卷 161-168页

作者： ZHU jia-zhen YI Hong-Wei HUANG Wei PANG Tao zhou Hui-Ping WU Xu-Dong State Key Laboratory of Pharmaceutical Biotechnology School of Life SciencesNanjing UniversityNanjing 210023China Department of Pharmacology School of MedicineSoutheast UniversityNanjing 210009China State Key Laboratory of Natural Medicines China Pharmaceutical UniversityNanjing 210009China Department of Microbiology and Immunology and Mc Guire Veterans Affairs Medical Center Virginia Commonwealth UniversityRichmond 23218USA

The liver is an important metabolic organ and controls lipid, glucose and energy metabolism. Dysruption of hepatic lipid metabolism is often associated with fatty liver diseases, including nonalcoholic fatty liver disease(NAFLD), alcoholic fatty liver diseases(AFLD) and hyperlipidemia. Recent studies have uncovered the contribution of hormones, transcription factors, and inflammatory cytokines to the pathogenesis of dyslipidemia and fatty liver diseases. Moreover, a significant amount of effort has been put to examine the mechanisms underlying the potential therapeutic effects of many natural plant products on fatty liver diseases and metabolic diseases. We review the current understanding of insulin, thyroid hormone and inflammatory cytokines in regulating hepatic lipid metabolism, focusing on several essential transcription regulators, such as Sirtuins(SIRTs), Forkhead box O(FoxO), Sterol-regulatory element-binding proteins(SREBPs). We also discuss a few representative natural products with promising thereapeutic effects on fatty liver disease and dyslipidemia.

关键词： Fatty liver disease Lipid metabolism Hormones Transcription factors Inflammatory cytokines Natural products

Microcarriers promote the through interface movement of mouse trophoblast stem cells by regulating stiffness

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Bioactive Materials 2023年第10期28卷 196-205页

作者： Zili Gao jia Guo Bo Gou zhen Gu Tan jia Sinan Ma Liyuan jiang Wenli Liu Lixun zhou Qi Gu State Key Laboratory of Membrane Biology The State Key Laboratory of Stem Cell and Reproductive BiologyInstitute of ZoologyChinese Academy of SciencesBeijing100101PR China Beijing Institute for Stem Cell and Regenerative Medicine Beijing100101PR China University of Chinese Academy of Sciences Beijing100049PR China Department of Chemistry and Biological Engineering University of Science and TechnologyBeijing100083PR China School of Life Sciences Northeast Agricultural UniversityHarbin150030PR China

Mechanical force is crucial in the whole process of embryonic ***,the role of trophoblast mechanics during embryo implantation has rarely been *** this study,we constructed a model to explore the effect of stiffness changes in mouse trophoblast stem cells(mTSCs)on implantation:microcarrier was prepared by sodium alginate using a droplet microfluidics system,and mTSCs were attached to the microcarrier surface with laminin modifications,called T(micro).Compared with the spheroid,formed by the self-assembly of mTSCs(T(sph)),we could regulate the stiffness of the microcarrier,making the Young’s modulus of mTSCs(367.70±79.81 Pa)similar to that of the blastocyst trophoblast ectoderm(432.49±151.90 Pa).Moreover,T(micro)contributes to improve the adhesion rate,expansion area and invasion depth of ***,T(micro)was highly expressed in tissue migration-related genes due to the activation of the Rho-associated coiled-coil containing protein kinase(ROCK)pathway at relatively similar modulus of ***,our study explores the embryo implantation process with a new perspective,and provides theoretical support for understanding the effect of mechanics on embryo implantation.

关键词： Biomechanics Microcarriers Embryo implantation Cell migration

Anonymous-address-resolution model

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Frontiers of Information Technology & Electronic Engineering 2016年第10期17卷 1044-1055页

作者： Guang-jia SONG zhen-zhou JI School of Computer Science and Technology Harbin Institute of Technology Harbin 150001 China

Address-resolution protocol （ARP） is an important protocol of data link layers that aims to obtain the corresponding relationship between Internet Protocol （IP） and Media Access Control （MAC） addresses. Traditional ARPs （address-resolution and neighbor-discovery protocols） do not consider the existence of malicious nodes, which reveals destination addresses in the resolution process. Thus, these traditional protocols allow malicious nodes to easily carry out attacks, such as man-in-the-middle attack and denial-of-service attack. To overcome these weaknesses, we propose an anonymous-address-resolution （AS-AR） protocol. AS-AR does not publicize the destination address in the address-resolution process and hides the IP and MAC addresses of the source node, The malicious node cannot obtain the addresses of the destination and the node which initiates the address resolution; thus, it cannot attack. Analyses and experiments show that AS-AR has a higher security level than existing security methods, such as secure-neighbor discovery.

关键词： Network security Address resolution Neighbor discovery Anonymous

Hopping Parameter Expansion Technique in Noise Method for Disconnected Quark Loops

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Chinese Physics Letters 2018年第4期35卷 16-19页

作者： jia-Liang zhou zhen Cheng Guang-Yi Xiong jian-Bo Zhang Department of Physics Zhejiang University

We investigate the effectiveness of the hopping parameter expansion（HPE） combined with the Z（2） noise method in the calculation of the trace of the inverse of Wilson＇s Dirac operator and some other disconnected contributions.A numerical comparison of the standard deviation for the Z（2） noise method and HPE with the Z（2） noise method is carried out. It is found that there are noise reductions in all the quantities we calculated using the HPE with the Z（2） noise method. For the trace of the inverse of Wilson＇s Dirac operator, the HPE can reduce the statistical error by about 60%.

关键词： HPE Hopping Parameter Expansion Technique in Noise Method for Disconnected Quark Loops