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Test analysis of detection of damage to a complicated spatial model structure

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Acta Mechanica Sinica 2011年第3期27卷 399-405页

作者： Long-He xu zhong-Xian Li Jia-Ru Qian School of Civil Engineering Beijing Jiaotong University 100044 Beijing China School of Civil Engineering Tianjin University 300072 Tianjin China Department of Civil Engineering Tsinghua University 100084 Beijing China

A two-stage damage detection approach is proposed and experimentally demonstrated on a complicated spatial model structure with a limited number of measurements. In the experiment,five known damage patterns,including 3 brace damage cases and 2 joint damage cases,were simulated by removing braces and weakening beam鈥揷olumn connections in the structure. The limited acceleration response data generated by hammer impact were used for system identification,and modal parameters were extracted by using the eigensystem realization algorithm. In the first stage,the possible damaged locations are determined by using the damage index and the characteristics of the analytical model itself,and the extent of damage for those substructures identified at stage I is estimated in the second stage by using a second-order eigen-sensitivity approximation method. The main contribution of this paper is to test the two-stage method by using the real dynamic data of a complicated spatial model structure with limited sensors. The analysis results indicate that the two-stage approach is ableto detect the location of both damage cases,only the severity of brace damage cases can be assessed,and the reasonable analytical model is critical for successful damage detection.

关键词： Damage detection. Complicated structure. Two-stage approach - Eigen-sensitivity analysis. Joint dam- age

Immobilizing palladium nanoparticles on boron-oxygen-functionalized carbon nanospheres towards efficient hydrogen generation from formic acid

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Nano Research 2019年第12期12卷 2966-2970页

作者： Shan zhong Nobuko Tsumori Mitsunori Kitta Qiang xu Research Institute of Electrochemical Energy National Institute of Advanced Industrial Science and Technology(AIST)IkedaOsaka 563-8577Japan Graduate School of Engineering Kobe UniversityKobeHyogo 657-8501Japan Department of Applied Chemistry and Chemical Engineering Toyama National College of Technology13 Hongo-machiToyama 939-8630Japan AIST-Kyoto University Chemical Energy Materials Open Innovation Laboratory(ChEM-OIL) National Institute of Advanced Industrial Science and Technology(AIST)Kyoto 606-8501Japan

Carb on nanospheres(XC-72R)were functionalized by boron-oxygen(B-O)through coannealing with boric acid,to which highly dispersed palladium nanoparticles(Pd NPs)(-1.7 nm)were immobilized by a wet chemical reduction for the first *** resultant Pd/OB-C catalystexhibits significantly improved activity for the dehydrogenation from formic acid(FA)compared to pristine XC-72R supported Pd NPs(Pd/C).Impressively,by adding melamine precursor,the B-0 and nitrogen(N)-functionalized product OB-C-N displays an extremely high B content,ca.34 times higher than *** Pd/OB-C-N catalyst with an ultrafine Pd particle size of-1.4 nm shows a superb activity,with a turnoverfrequency(TOF)as high as 5,354 h^-1 at 323 K,owing to the uniform ultrafine Pd NPs and the effect from B-0 and N functionalities.

关键词： boron-oxygen function alization palladium formic acid heterogeneous catalysis hydrogen generation carbon nanosphere

Dynamic self-assembly of block copolymers regulated by time-varying building block composition via reversible chemical reaction

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Science China Chemistry 2019年第12期62卷 1666-1674页

作者： Duo xu Li Zhao Kuo Zhang zhong-Yuan Lu State Key Laboratory of Supramolecular Structure and Materials Institute of Theoretical ChemistryJilin UniversityChangchun 130023China College of Life Sciences Jilin UniversityChangchun 130012China

Dynamic self-assembly processes occurring out of thermodynamic equilibrium underlie many forms of adaptive and intelligent behaviors in natural *** of the continuous input of energy,the dynamic self-assembly provides the opportunity for creating structures that are unattainable in equilibrium *** this paper,we propose a strategy in the dynamic self-assembly of amphiphilic block copolymers regulated by reversible chemical *** time-dependently tuning the reaction direction in the simulations,the amphiphilicity of building block keeps changing *** on this dynamic process,we can obtain exotic self-assembled vesicle with surface pores which is otherwise metastable in an equilibrium *** effects induced by the type of chemical reaction and the reaction period are *** at short reaction period in suitable reversible reaction,novel self-assembly structure *** is attributed to the competition of reaction and diffusion in the dynamic process,by which the local component of building blocks alters a lot,leading to large local surface tension resulting in the formation of perforated *** order to predict the assembled structure in a dynamic process,we build up the relationship between component ratio P,the diffusion effect parameter Pdiff and assembled *** dynamic self-assembly regulated by chemical reaction holds great promise as a rational strategy to realize exotic functional materials that are not easily obtained in equilibrium.

关键词： dynamic self-assembly block copolymer reversible reaction computer simulation

Bounds for the Rainbow Disconnection Numbers of Graphs

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Acta Mathematica Sinica,English Series 2022年第2期38卷 384-396页

作者： xu Qing BAI zhong HUANG xue Liang LI Center for Combinatorics and LPMC Nankai UniversityTianjin 300071P.R.China

An edge-cut of an edge-colored connected graph is called a rainbow cut if no two edges in the edge-cut are colored the *** edge-colored graph is rainbow disconnected if for any two distinct vertices u and v of the graph,there exists a rainbow cut separating u and *** a connected graph G,the rainbow disconnection number of G,denoted by rd(G),is defined as the smallest number of colors required to make G rainbow *** this paper,we first give some upper bounds for rd(G),and moreover,we completely characterize the graphs which meet the upper bounds of the NordhausGaddum type result obtained early by ***,we propose a conjecture that for any connected graph G,either rd(G)=λ^(+)(G)or rd(G)=λ^(+)(G)+1,whereλ^(+)(G)is the upper edge-connectivity,and prove that the conjecture holds for many classes of graphs,which supports this ***,we prove that for an odd integer k,if G is a k-edge-connected k-regular graph,thenχ’(G)=k if and only if rd(G)=*** implies that there are infinitely many k-edge-connected k-regular graphs G for which rd(G)=λ^(+)(G)for odd k,and also there are infinitely many k-edge-connected k-regular graphs G for which rd(G)=λ^(+)(G)+1 for odd *** k=3,the result gives rise to an interesting result,which is equivalent to the famous Four-Color ***,we give the relationship between rd(G)of a graph G and the rainbow vertex-disconnection number rvd(L(G))of the line graph L(G)of G.

关键词： Edge-coloring edge-connectivity rainbow disconnection coloring(number) line graph

Existence and Properties of Solutions for a Class of Fractional Differential Equations

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Acta Mathematicae Applicatae Sinica 2021年第3期37卷 477-484页

作者： Yong-qiang xu Shu-hong CHEN zhong TAN School of Mathematics and Statistics Minnan Normal UniversityZhangzhou 363000China School of Mathematical Sciences Xiamen UniversityXiamen 361005China

In this paper,we consider the initial value problem of a class of fractional differential ***,we obtain the existence and uniqueness of the solutions by using Picard’s method of successive *** we discuss the dependen... 详细信息

关键词： existence uniqueness fractional derivative equations

Precipitate Phases in an 11% Cr Ferritic/Martensitic Steel with Tempering and Creep Conditions

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Acta Metallurgica Sinica(English Letters) 2015年第1期28卷 48-57页

作者： Xiao-Ling Zhou Yin-zhong Shen Zhi-Qiang xu School of Mechanical Engineering Shanghai Jiao Tong University

Precipitates in an 11% Cr ferritic/martensitic steel containing Nd with tempering and creep conditions were investigated using transmission electron microscope with energy-dispersive X-ray spectroscopy. The precipitates in the steel with a tempering condition were identified to be Cr-rich M23C6 carbide, Nb-rich/V-rich/Ta–Nb-rich MX carbides, Nbrich MX carbonitride, and Fe-rich M5C2 carbide. Nd-rich carbonitride, which is not known to have been reported previously in steels, was also detected in the steel after tempering. Most of the Nb-rich MX precipitates were dissolved, whereas the amount of Ta-rich MX precipitates was increased significantly in the steel after a creep test at 600 °C at an applied stress of180 MPa for 1,100 h. No Fe2 W Laves phase has been detected in the steel after tempering.（Fe, Cr）2W Laves phase with a relatively large size was observed in the steel after the creep test.

关键词： Precipitate phase High-Cr ferritic/martensitic steel High temperature creep Transmission electron microscope

The Crystallization Behavior of Biodegradable Poly(butylene succinate) in the Presence of Organically Modified Clay with a Wide Range of Loadings

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Chinese Journal of Polymer Science 2015年第4期33卷 576-586页

作者： Jing-bin Chen Jia-zhuang xu Huan xu zhong-ming Li 钟淦基雷军 College of Polymer Science and Engineering and State Key Laboratory of Polymer Materials Engineering Sichuan University

The crystallization behavior of poly（butylene succinate）（PBS） nanocomposites with a wide range of contents of clays was revealed. It was of interest to find that the crystallization rate of PBS was accelerated obviously at relatively low contents of clays; while a retarded crystallization kinetics and a decreased crystallinity of PBS were found in the nanocomposites with higher clay contents. Two interplaying effects existed in the nanocomposites, i.e., a suppression effect of clays on nucleation and a templating effect of clays on crystal growth, were clarified to contribute to this intriguing crystallization behavior.

关键词： Poly(butylene succinate) Clay Crystallization kinetics Biodegradable.

Extended Object Model for Product Configuration Design

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International Journal of Automation and computing 2010年第3期7卷 289-294页

作者： Zhi-Wei xu Ze-zhong Liang zhong-Qi Sheng School of Mechanical Engineering and Automation Northeastern University Shenyang 110004 PRC

This paper presents an extended object model for case-based reasoning （CBR） in product configuration design. In the extended object model, a few methods of knowledge expression are adopted, such as constraints, rules, objects, etc. On the basis of extended object model, case representation model for CBR is applied to product configuration design system. The product configuration knowledge can be represented by the extended object. The model can support all the processes of CBR in product configuration design, such as case representation, indexing, retrieving, and case revising. The presented model is an extension of the traditional object-oriented model by including the relationship class used to express the relation between the cases, constraints class used in the product configuration knowledge representation, index class used in ease retrieving, and solution class used in case revising. Therefore, the product configuration knowledge used in the product configuration design can be represented by using this model. In the end, a metering pump product configuration design system is developed on the basis of the proposed product configuration model to support customized products.

关键词： Mass customization product configuration case-based reasoning (CBR) object-oriented modeling case representation.

The immunophilin CYCLOPHILIN28 affects PSII-LHCII supercomplex assembly and accumulation in Arabidopsis thaliana

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Journal of Integrative Plant Biology 2022年第4期64卷 915-929页

作者： Weining Zhu Linqing xu Xiaoxia Yu Ying zhong Chinese Education Ministry's Key Laboratory of Western Resources and Modern Biotechnology Key Laboratory of Biotechnology Shaanxi ProvinceCollege of Life SciencesNorthwest UniversityXi'an 710069China

In plant chloroplasts,photosystem II(PSII)complexes,together with light-harvesting complex II(LHCII),form various PSII-LHCII supercomplexes(SCs).This process likely involves immunophilins,but the underlying regulatory mechanisms are ***,by comparing Arabidopsis thaliana mutants lacking the chloroplast lumen-localized immunophilin CYCLOPHILIN28(CYP28)to wildtype and transgenic complemented lines,we determined that CYP28 regulates the assembly and accumulation of PSII-LHCII *** to the wild type,cyp28 plants showed accelerated leaf growth,earlier flowering time,and enhanced accumulation of high molecular weight PSII-LHCII SCs under normal light *** lack of CYP28 also significantly affected the electron transport *** native-polyacrylamide gel electrophoresis analysis revealed more Lhcb6 and less Lhcb4 in M-LHCII-Lhcb4-Lhcb6 complexes in cyp28 versus wild-type ***-prolyl cis/trans isomerase(PPIase)activity assays revealed that CYP28 exhibits weak PPIase activity and that its K113 and E187 residues are critical for this *** analysis suggested that CYP28 may regulate PSIILHCII SC accumulation by altering the configuration of Lhcb6 via its PPIase ***,the Lhcb6-P139 residue is critical for PSII-LHCII SC assembly and ***,our findings suggest that CYP28 likely regulates PSII-LHCII SC assembly and accumulation by altering the configuration of P139 of Lhcb6 via its PPIase activity.

关键词： cyclophilin28 immunophilin peptidyl-prolyl cis/trans isomerase activity photosynthesis PSII-LHCII supercomplexes thylakoid lumen