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Applied Mathematics and Mechanics(English Edition) 2022年第4期43卷 603-614页

作者： si yuan Quan yuan Department of Civil Engineering Key Laboratory of Civil Engineering Safety and Durability of China Education MinistryTsinghua UniversityBeijing 100084China

A new type of Galerkin finite element for first-order initial-value problems(IVPs)is *** the trial and test functions employ the same m-degreed *** adjoint equation is used to eliminate one degree of freedom(DOF)from the test function,and then the so-called condensed test function and its consequent condensed Galerkin element are *** is mathematically proved and numerically verified that the condensed element produces the super-convergent nodal solutions of O(h^(2m+2)),which is equivalent to the order of accuracy by the conventional element of degree m+*** related properties are addressed,and typical numerical examples of both linear and nonlinear IVPs of both a single equation and a system of equations are presented to show the validity and effectiveness of the proposed element.

关键词： Galerkin method finite element method(FEM) condensed element superconvergence adjoint operator initial-value problem(IVP)

P-FEMOL ANALYsiS OF PLATE BENDING PROBLEMS

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Acta Mechanica Solida sinica 1994年第1期7卷 39-45页

作者： si, yuan Tsinghua Univ Beijing China

In this paper, the p- version of the finite element method of lines (FEMOL) for the analysis of the Mindlin-Reissner plate bending problems is presented and a class of p-FEMOL elements with polynomial degrees as high as nine is developed. Numerical examples given in this paper show tremendous performance of the present method: namely, rapid convergence rate, high accuracy for both displacements and stress resultants, removal of shear-locking trouble, capability of dealing with difficult problems such as the boundary layer behavior near a free edge and stress concentration around a hole.

关键词： Bending (deformation) Boundary layers Convergence of numerical methods Differential equations Finite element method Geometry Mathematical models Performance Plates (structural components) Polynomials Stresses

Recursive super-convergence computation for multi-dimensional problems via one-dimensional element energy pro jection technique

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Applied Mathematics and Mechanics(English Edition) 2018年第7期39卷 1031-1044页

作者： si yuan Yue WU Qinyan XING Key Laboratory of Civil Engineering Safety and Durability of China Education Ministry Department of Civil Engineering Tsinghua University

This paper presents a strategy for computation of super-convergent solutions of multi-dimensional problems in the finite element method （FEM） by recursive application of the one-dimensional （1D） element energy projection （EEP） technique. The main idea is to conceptually treat multi-dimensional problems as generalized 1D problems, based on which the concepts of generalized 1D FEM and its consequent EEP formulae have been developed in a unified manner. Equipped with these concepts, multi-dimensional problems can be recursively discretized in one dimension at each step, until a fully discretized standard finite element （FE） model is reached. This conceptual dimension-by- dimension （D-by-D） discretization procedure is entirely equivalent to a full FE discretization. As a reverse D-by-D recovery procedure, by using the unified EEP formulae together with proper extraction of the generalized nodal solutions, super-convergent displacements and first derivatives for two-dimensional （2D） and three-dimensional （3D） problems can be obtained over the domain. Numerical examples of 3D Poisson＇s equation and elasticity problem are given to verify the feasibility and effectiveness of the proposed strategy.

关键词： three-dimensional(3D)problem generalized one-dimensional(1D)finiteelement method (FEM) dimension-by-dimension(D-by-D) super-convergence elementenergy projection(EEP)

Biological Eagle-eye Inspired Target Detection for Unmanned Aerial Vehicles Equipped with a Manipulator

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Machine Intelligence Research 2023年第5期20卷 741-752页

作者： Yi-Min Deng si-yuan Wang School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China

Inspired by eagle eye mechanisms,the structure and information processing characteristics of the eagle′s visual system are used for the target capture task of an unmanned aerial vehicle(UAV)with a mechanical *** this paper,a novel eagle-eye inspired multi-camera sensor and a saliency detection method are proposed.A combined camera system is built by simulating the double fovea structure on the eagle retina.A saliency target detection method based on the eagle midbrain inhibition mechanism is proposed by measuring the static saliency information and dynamic ***,salient targets can be accurately detected through the collaborative work between different cameras of the proposed multi-camera *** results show that the eagle-eye inspired visual system is able to continuously detect targets in outdoor scenes and that the proposed algorithm has a strong inhibitory effect on moving background interference.

关键词： Unmanned aerial vehicle(UAV) eagle eye multi-camera sensor target detection saliency detection

Increased Preoperative Glucose Variability Is Associated with Adverse Perioperative Outcomes Following Orthopedic Surgery in Patients with Type 2 Diabetes Mellitus

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Current Medical Science 2020年第3期40卷 523-529页

作者： si-jie yuan Jie SHEN Department of Endocrinology and Metabolic Diseases The Third Affiliated HospitalSouthern Medical UniversityGuangzhou510630China

The association between glucose variability(GV)and adverse perioperative outcomes in type 2 diabetes mellitus(T2DM)patients undergoing orthopedic surgery was investigated.A retrospective cohort study was performed by analyzing data on T2DM patients receiving continuous blood glucose(BG)monitoring and continuous subcutaneous insulin infusion treatment due to poorly controlled preoperative BG prior to orthopedic *** was assessed with coefficient of variation(CV).Postoperative and perioperative CV,hypoglycemia cases,and other perioperative outcomes(diabetes preparation time[DPT],length of stay[LOS],and perioperative and infective complication cases)were *** showed that a total of 168 patients were grouped into preoperative CV tertiles:1st(n=56):0–0.2921,2nd(n=58):0.2922–0.3779,and 3rd(n=54):0.3780–*** blood glucose(FBG),perioperative CV,rate of hypoglycemia cases(OR:5.53,95%CI:2.43–12.59)(all Psion analysis indicated that the 3rd tertile was associated with increased perioperative CV(adjusted coefficient=0.515,Psion,preoperative GV is associated with increased perioperative GV and adverse perioperative outcomes including longer DPT and higher rates of hypoglycemia and perioperative complications.

关键词： glycemic variability orthopedics perioperative period type 2 diabetes mellitus

The Stability of Banach Frames in Banach Spaces

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Acta Mathematica sinica,English Series 2010年第12期26卷 2369-2376页

作者： Yu Can ZHU si yuan WANG Department of Mathematics Fuzhou University Fuzhou 350108 P. R. China Department of Mathematics Shangrao Normal School Shangrao 334000 P. R. China

In this paper, we give some equivalent conditions on a Banach frame for a Banach space by using the pseudoinverse operator. We also consider the stability of a Banach frame for a Banach space X with respect to Xd or an Xd-frame for a Banach space X under perturbation. These results generalize and improve the related works of Balan, Casazza, Christensen, Stoeva and Jian et al.

关键词： Frame Banach frame Xd-frame pseudoinverse operator

The Anion Binding Affinity Determines the Strength of Anion Specificities of Thermosensitive Polymers

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Chinese Journal of Polymer Science 2021年第11期39卷 1351-1356页

作者： Lei-Lei Lian si-yuan Xu Hai-Yang yuan Guang-Ming Liu Hefei National Laboratory for Physical Sciences at the Microscale Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education InstitutesDepartment of Chemical PhysicsUniversity of Science and Technology of ChinaHefei 230026China

In this work,we demonstrate that the strength of anion specificities of thermosensitive polymers is determined by the affinity of direct anion binding to the *** have prepared a series of thermosensitive statistical copolymers with distinct thermoresponsive *** anions can specifically interact with the different types of thermosensitive polymers in very different strengths.A similar strength of specific anion effects on thermoresponsive behaviors can be observed at very different salt concentrations for the different types of thermosensitive polymers.A stronger anion binding to the thermosensitive polymers gives rise to a more obvious anion specificity and vice *** work presented here opens up opportunities for the application of ion binding affinity to modulate the strength of ion specificities of thermosensitive polymers.

关键词： Specific ion effect Polyzwitterion Ion-polymer interaction Thermosensitivity Ion-pairing

Valence of elements in HgBa_2Ca_(n-1)Cu_nO_(2n+2+δ)(n=1, 2, 3, 4)

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Chinese Chemical Letters 2000年第12期11卷 1111-1112页

作者： Zhi Jian WU si yuan ZHANG Laboratory of Rare Earth Chemistry and Physics Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022

Valence of elements in HgBa_2Ca_(n-1)Cu_nO_(2n+2+δ)(n=1, 2, 3, 4) (both argon and oxygen annealed samples) were calculated. The result indicated for both argon and oxygen annealed samples, Hg had the lowest valence for the highest Tc sample. For fixed n, the valence of Cu in oxygen annealed samples was larger than that in argon annealed samples, indicating that oxygen annealed samples produce more carriers than argon annealed samples.

关键词： Valence HgBa_2Ca_(n-1)Cu_nO_(2n+2+δ)(n=1, 2, 3, 4).

COMPUTATION OF STRESS INTENsiTY FACTORS BY THE SUB-REGION MIXED FINITE ELEMENT METHOD OF LINES

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Acta Mechanica Solida sinica 2007年第2期20卷 149-162页

作者： yuan si Xu Yongjun WILLIAMS F W Department of Civil Engineering Tsinghua University Beijing 100084 China Institute of Mechanics Chinese Academy of Sciences Beijing 100080 China Structural Engineering Division Cardiff University Cardiff CF2 3TB UK

Based on the sub-region generalized variationM principle, a sub-region mixed version of the newly-developed semi-analytical ＇finite element method of lines＇（FEMOL） is proposed in this paper for accurate and efficient computation of stress intensity factors （siFs） of two-dimensional notches/cracks. The circular regions surrounding notch/crack tips are taken as the complementary energy region in which a number of leading terms of singular solutions for stresses are used, with the sought siFs being among the unknown coefficients. The rest of the arbitrary domain is taken as the potential energy region in which FEMOL is applied to obtain approximate displacements. A mixed system of ordinary differential equations （ODEs） and algebraic equations is derived via the sub-region generalized variational principle. A singularity removal technique that eliminates the stress parameters from the mixed equation system eventually yields a standard FEMOL ODE system, the solution of which is no longer singular and is simply and efficiently obtained using a standard general-purpose ODE solver. A number of numerical examples, including bi-material notches/cracks in anti-plane and plane elasticity, are given to show the generally excellent performance of the proposed method.

关键词： stress intensity factors finite element method of lines sub-region generalized variational principle ordinary differential equation solver

Hydrogen-rich surface of MoC catalysts for efficient CO_(2) hydrogenation induced by a coupled hydrogen donator

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Nano Research 2024年第8期17卷 7762-7767页

作者： Dong Xu si-yuan Xia Qi-yuan Li Jie-Sheng Chen Xin-Hao Li School of Chemistry and Chemical Engineering Frontiers Science Center for Transformative MoleculesShanghai Jiao Tong UniversityShanghai 200240China

Direct CO_(2) hydrogenation offers an important strategy for promoting the global carbon balance,but high thermodynamic and kinetic stability of CO_(2) has restricted its applicability to only a handful of industrial ***,we introduce a proof-of-concept application of the electron-rich Pt surface to promote hydrogen donation for electron-rich MoC particles acting as hydrogen acceptors,thereby constructing hydrogen-rich surface of MoC active ***,the formed hydrogen-rich and electronrich surface could greatly decrease reaction activation energy to boost the efficient CO_(2) hydrogenation into formic acid over the MoC *** optimized MoC@NC/Pt-0.1(NC:nitrogen-doped carbon)catalyst exhibits a high turnover frequency(TOF)value of 1.2 h^(−1) at a lower temperature of 60℃and a TOF of 24.2 h^(−1) under standard reaction conditions widely used in the literature,exceeding 7 times of MoC@NC catalyst and surpassing the benchmark classical non-noble metal active center-based heterogeneous catalyst.

关键词： electron-rich Pt nanoparticles hydrogen donation hydrogen-rich MoC nanoparticles CO_(2) hydrogenation formic acid