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Model Order Reduction for Coupled Dynamic Characterization of Torsional Micromirrors

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Chinese Journal of Mechanical Engineering 2011年第5期24卷 829-835页

作者： shi Jian zhang Shuyou Department of Mechanical Engineering Zhejiang University Hangzhou 310027 China

Numerical solutions could not perform rapid system-level simulation of the behavior of micro-electro-mechanical systems（MEMS） and analytic solutions for the describing partial differential equations are only available for simple *** order reduction（MOR） can extract approximate low-order model from the original large scale *** model order reduction algorithm is based on first-order system model,however,most structure mechanical MEMS systems are naturally second-order in *** the purpose of solving the above problem,a direct second-order system model order reduction approach based on Krylov subspace projection for the coupled dynamic study of electrostatic torsional micromirrors is *** block Arnoldi process is applied to create the orthonormal vectors to construct the projection matrix,which enables the extraction of the low order model from the discretized system assembled through finite element *** transfer functions of the reduced order model and the original model are expanded to demonstrate the moment-matching property of the second-order model reduction *** torsion and bending effect are included in the finite element model,and the squeeze film damping effect is considered as *** empirical method considering relative error convergence is adopted to obtain the optimal choice of the order for the reduced model.A comparison research between the full model and the reduced model is carried *** modeling accuracy and computation efficiency of the presented second-order model reduction method are confirmed by the comparison research *** research provides references for MOR of MEMS.

关键词： model order reduction torsional micromirror moment-matching

A Simple Empirical Formula for Predicting the Ultimate Strength of ship Plates with Elastically Restrained Edges in Axial Compression

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China Ocean Engineering 2020年第4期34卷 571-580页

作者： LIU Cong zhang shi-lian State Key Laboratory of Ocean Engineering Shanghai Jiao Tong UniversityShanghai 200240China Collaborative Innovation Center for Advanced ship and Deep-Sea Exploration Shanghai 200240China

An investigation is conducted on the static ultimate limit state assessment of ship hull plates with elastically restrained edges subjected to axial *** material and geometric non-linearities were considered in finite element(FE)*** initial geometric imperfection of the plate was considered,while the residual stress introduced by welding was not *** ultimate strength of simply supported ship hull plates compared well with the existing empirical formula to validate the correctness of the applied boundary conditions,initial imperfection and mesh *** extensive FE calculations on the ultimate strength of ship hull plates with elastically restrained edges are *** a new simple empirical formula for plate ultimate strength is developed,which includes the effect of the rotational restraint stiffness,rotational restraint stiffness,and aspect *** applying the new formula and FE method to ship hull plates in real ships,a good coincidence of the results between these two methods is obtained,which indicates that the new formula can accurately predict the ultimate strength of ship hull plates with elastically restrained edges.

关键词： ship hull plate ultimate strength axial compression elastically restrained edges empirical formula

Metabolic and transcriptomic analyses elucidate a novel insight into the network for biosynthesis of carbohydrate and secondary metabolites in the stems of a medicinal orchid Dendrobium nobile

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Plant Diversity 2023年第3期45卷 326-336页

作者： Yu-Wen zhang Yu-Cen shi shi-Bao zhang Key Laboratory of Economic Plants and Biotechnology Kunming Institute of BotanyChinese Academy of SciencesKunming 650201YunnanChina Yunnan Key Laboratory for Wild Plant Resources Kunming 650201YunnanChina University of Chinese Academy of Sciences Beijing 100049China Lijiang Forest Biodiversity National Observation and Research Station Kunming Institute of BotanyChinese Academy of SciencesLijiang 674100YunnanChina

Dendrobium nobile is an important medicinal and nutraceutical *** the ingredients of *** have been identified as polysaccharides,alkaloids,amino acids,flavonoids and bibenzyls,our understanding of the metabolic pathways that regulate the synthesis of these compounds is ***,we used transcriptomic and metabolic analyses to elucidate the genes and metabolites involved in the biosynthesis of carbohydrate and several secondary metabolites in the stems of ***.A total of 1005 metabolites and 31,745 genes were detected in the stems of *** majority of these metabolites and genes were involved in the metabolism of carbohydrates(fructose,mannose,glucose,xylulose and starch),while some were involved in the metabolism of secondary metabolites(alkaloids,β-tyrosine,ferulic acid,4-hydroxybenzoate and chrysin).Our predicted regulatory network indicated that five genes(AROG,PYK,DXS,ACEE and HMGCR) might play vital roles in the transition from carbohydrate to alkaloid *** analysis identified that six genes(ALDO,PMM,BGLX,EGLC,XYLB and GLGA) were involved in carbohydrate metabolism,and two genes(ADT and CYP73A) were involved in secondary metabolite *** analyses also indicated that phosphoenol-pyruvate(PEP) was a crucial bridge that connected carbohydrate to alkaloid *** regulatory network between carbohydrate and secondary metabolite biosynthesis established will provide important insights into the regulation of metabolites and biological systems in Dendrobium species.

关键词： Dendrobium nobile Transcriptome Metabolome Polysaccharides Alkaloids Secondary metabolite biosynthesis

Strong Convergence Theorems for Strictly Asymptotically Pseudocontractive Mappings in Hilbert Spaces

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Acta Mathematica Sinica,English Series 2011年第7期27卷 1367-1378页

作者： shi Sheng zhang Department of Mathematics Yibin University Yibin 644007 P. R. China

The purpose of this paper is by using CSQ method to study the strong convergence problem of iterative sequences for a pair of strictly asymptotically pseudocontractive mappings to approximate a common fixed point in a Hilbert space. Under suitable conditions some strong convergence theorems are proved. The results presented in the paper are new which extend and improve some recent results of Acedo and Xu [Iterative methods for strict pseudo-contractions in Hilbert spaces. Nonlinear Anal., 67（7）, 2258-2271 （2007）], Kim and Xu [Strong convergence of modified Mann iterations for asymptoti- cally nonexpansive mappings and semigroups. Nonlinear Anal., 64, 1140-1152 （2006）], Martinez-Yanes and Xu [Strong convergence of the CQ method for fixed point iteration processes. Nonlinear Anal., 64, 2400-2411 （2006）], Nakajo and Takahashi pings and nonexpansive semigroups. J. Math [Strong convergence theorems for nonexpansive map- Anal. Appl., 279, 372-379 （2003）], Marino and Xu [Weak and strong convergence theorems for strict pseudocontractions in Hilbert spaces. J. Math. Anal. Appl., 329（1）, 336-346 （2007）], Osilike et al. [Demiclosedness principle and convergence theorems for k-strictly asymptotically pseudocontractive maps. J. Math. Anal. Appl., 326, 1334-1345 （2007）], Liu [Convergence theorems of the sequence of iterates for asymptotically demicontractive and hemicontractive mappings. Nonlinear Anal., 26（11）, 1835-1842 （1996）], Osilike et al. [Fixed points of demi-contractive mappings in arbitrary Banach spaces. Panamer Math. J., 12（2）, 77-88 （2002）], Gu [The new composite implicit iteration process strictly pseudocontractive mappings. J. Math with errors for common fixed points of a finite family of Anal. Appl., 329, 766-776 （2007）].

关键词： Strictly asymptotically pseudocontractive mapping strictly pseudocontractive mapping of Browder Petryshyn type CSQ methods common fixed point

On a Sharp Volume Estimate for Gradient Ricci Solitons with Scalar Curvature Bounded Below

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Acta Mathematica Sinica,English Series 2011年第5期27卷 871-882页

作者： shi Jin zhang Beijing International Center for Mathematical Research Peking University Beijing 100871 P. R. China

In this note, we obtain a sharp volume estimate for complete gradient Ricci solitons with scalar curvature bounded below by a positive constant. Using Chen-Yokota＇s argument we obtain a local lower bound estimate of the scalar curvature for the Ricci flow on complete manifolds. Consequently, one has a sharp estimate of the scalar curvature for expanding Ricci solitons; we also provide a direct （elliptic） proof of this sharp estimate. Moreover, if the scalar curvature attains its minimum value at some point, then the manifold is Einstein.

关键词： Ricci solitons Einstein manifold scalar curvature

Weak Convergence Theorem for Lipschizian Pseudocontraction Semigroups in Banach Spaces

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Acta Mathematica Sinica,English Series 2010年第2期26卷 337-344页

作者： shi Sheng zhang Department of Mathematics Yibin University Yibin 644007 Sichuan P. R. China

The purpose of this paper is to study the weak convergence problems of the irnplicity iteration process for Lipschitzian pseudocontraction semigroups in general Banach spaces. The results presented in this paper extend and improve the corresponding results of Zhou [Nonlinear Anal., 68, 2977-2983 （2008）], Chen, et ah [J. Math. Anal. Appl., 314, 701 709 （2006）], Xu and Ori [Numer. Funct. Anal. Optim, 22, 767-773 （2001）] and Osilike [J. Math. Anal. Appl., 294, 73-81 （2004）]. Keywords

关键词： Lipschitzian pseudocontraction semigroup demi-closed principle common fixed point Opial condition strongly pseudocontractive mapping implicit iteration process

Performance Analysis of Anti-Interference UWB-OFDM System

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The Journal of China Universities of Posts and Telecommunications 2006年第2期13卷 6-9,38页

作者： zhang shi-bing CAO shi-ke zhang Li-jun Communication and Information Engineering Institute Nanjing University of Posts and Telecommunications Nanjing 210003 P.R. China School of Electronics and Information Nantong University Nantong 226007 P.R. China

This paper examines the robustness of anti-interference Ultra-Wide-Band UWB-OFDM （AI-UWB） systems in presence of narrow-band interference. It analyzes the bit error rate performance of the systems in both the single-user and multi-user modes, and compares its robustness in different code matrixes. By encoding transmitted symbols and spreading their power over all sub-bands, AI-UWB systems can make full use of the frequency diversity across the sub-bands and have more robustness to the narrowband interference. Simulating results show that different codes have almost the same robustness to the narrowband interference. The encoding and spreading could suppress the narrowband interference effectively. Compared with the IS-UWB systems, our approach has more than 5 dB interference margin.

关键词： UWB anti-interference bit error rate coding spreading

High-voltage aqueous zinc-ion batteries with conversion-type anode and modified electrolyte

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National Science Review 2024年第8期11卷 50-51页

作者： Junnan Hao shi-zhang Qiao School of Chemical Engineering The University of Adelaide

Aqueous zinc-ion batteries (AZIBs) with near-neutral electrolytes have attracted wide attention for their high safety, low cost and environmental friendliness,making them a promising candidate for sustainable energy storage. However, the development of high-voltage AZIBs has been hindered by the limited choice of anode materials and the interfacial incompatibility between the electrode and the electrolyte [1].

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Metal-organic framework assisted synthesis of single-atom catalysts for energy applications

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National Science Review 2018年第5期5卷 626-627页

作者： Yao Zheng shi-zhang Qiao School of Chemical Engineering The University of Adelaide School of Materials Science and Engineering Tianjin University

Metal single-atom catalysts (M-SACs)are emerging as a new research frontier because of their low-coordination metal atoms and uniform structures. As a representation of maximum atom utilization efficiency, M-SACs demonstrate unique properties in a wide variety of heterogeneous catalysis and electrocatalytic processes [1,2]. Metal-organic frameworks (MOFs) are composed of metal-

关键词： Co Metal-organic framework assisted synthesis of single-atom catalysts for energy applications ZIF Ni