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Time Decay Rates of the Isotropic Non-Newtonian Flows in R^n

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Acta Mathematicae Applicatae Sinica 2007年第1期23卷 99-106页

作者： bo-qing Dong School of Mathematical Sciences Nankai University Tianjin 300071 China

This paper is concerned with time decay rates for weak solutions to a class system of isotropic incompressible non-Newtonian fluid motion in R^n. With the use of the spectral decomposition methods of Stokes operator, the optimal decay estimates of weak solutions in L^2 norm are derived under the different conditions on the initial velocity. Moreover, the error estimates of the difference between non-Newtonian flow and Navier-Stokes flow are also investigated.

关键词： L^2 decay spectral decomposition non-Newtonian flows

On a Certain Sum-product Estimate in Fields of Prime Order

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Acta Mathematica Sinica,English Series 2014年第11期30卷 1861-1866页

作者： bo qing XUE Academy of Mathematics and Systems Science Chinese Academy of Sciences

Let Fp be the finite field of p elements with p *** A is a subset of Fp and g is an element of F＊p with order ν,then max{｜A ＋ g·A｜,｜A·A｜} （ν/（ν ＋｜A｜2））1/12｜A｜13/12.

关键词： Sum-product estimate different sets fields of prime order

On the rate of convergence of two generalized Bernstein type operators

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Applied Mathematics(A Journal of Chinese Universities) 2020年第3期35卷 321-331页

作者： LIAN bo-yong CAI qing-bo Department of Mathematics Yang-En UniversityQuanzhou 362014China School of Mathematics and Computer Science Quanzhou Normal UniversityQuanzhou 362000China

In this paper,we introduce the Bézier variant of two new families of generalized Bernstein type *** establish a direct approximation by means of the Ditzian-Totik modulus of smoothness and a global approximation theorem in terms of second order modulus of *** means of construction of suitable functions and the method of bojanic and Cheng,we give the rate of convergence for absolutely continuous functions having a derivative equivalent to a bounded variation function.

关键词： Bernstein operators modulus of smoothness rate of convergence bounded variation

Load-carrying capacity and practical calculation method for hollow cylinder joints connected with H-shaped beams

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2012年第3期13卷 174-181页

作者： Hui WU bo-qing GAO Qiang CHEN Finance and Economics of Zhejiang College Hangzhou 310018 China College of Civil Engineering and Architecture Zhejiang University Hangzhou 310058 China

A type of hollow cylinder joints connected with H-shaped beams is proposed for spatial structures. Based on von Mises yield criterion and perfect elasto-plasticity model, a series of finite element models of the joints is established, in which the effect of geometric nonlinearity is taken into account. Then mechanical behavior and load-carrying capacity of the joints were investigated, which were subjected to axial load, in- and out-plane bending moments, and their combinations. The results show that the ultimate loads of the joints are determined by the maximum displacement. Furthermore, the case of one joint connected with multiple beams was discussed. Experiments on a set of typical full-scale joints were conducted to understand the structural behavior and the failure mechanism of joint, and also to validate the finite element models. Finally, the practical calculation method was established through finite elements analysis (FEA) results and numerical fitting. The results show that the joints are more ductile and materially economical than welded hollow spherical joints, and the practical calculation method can provide a reference for direct design and the revision of relevant design codes.

关键词： Hollow cylinder joints H-shaped beams Load-carrying capacity Finite elements analysis (FEA) Practical calcu-lation method

The Effective AC Response of Nonlinear Composites

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Communications in Theoretical Physics 2001年第4期35卷 501-504页

作者： WEIEn－bo GUGuo－qing CollegeofPowerEngineering UniversityofshanghaiScienceandTechnologyShanghai200093China

A perturbative approach is used to study the AC response of nonlinear composite media, which obey a current-field relation of the form with components having nonlinear response at finite frequencies. For a sinusoidal applied field, we extend the local potential in terms of sinusoidal components at fundamental frequency and high-order harmonic frequencies to treat the nonlinear composites. For nonlinear composite media with a low concentrations of spherical inclusions, we give the formulae of the nonlinear effective AC susceptibility at the third harmonic frequency.

关键词： nonlinear composite effective nonlinear susceptibility

A milestone in methane conversion

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National Science Review 2014年第3期1卷 325-326页

作者： bo-qing Xu Department of Chemistry Tsinghua University

Direct conversion of methane,the dominating component of natural and shale gases,into key chemical feedstock and liquid fuels has long been a big challenge in chemistry and chemical engineering[1,2].he industrial processes for methane-resourced higher hydrocarbons(*** and gasoline)are based on indirect methane conversion integrating several catalytic reaction *** production of syngas(a mix-

关键词： high A milestone in methane conversion

On Sums of Sparse Prime Subsets

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Acta Mathematica Sinica,English Series 2013年第8期29卷 1535-1542页

作者： Zhen CUI Hong Ze LI bo qing XUE Department of Mathematics Shanghai Jiao Tong University

For arbitrary c00, if A is a subset of the primes less than x with cardinality δx（logx）-1, δ≥（logx）-c0, then there exists a positive constant c such that the cardinality of A＋A is larger than cδx（loglogx）-1.

关键词： Density subsets subsets of the primes circle method sifted numbers

Parameter Estimation for the Discretely Observed Vasicek Model with Small Fractional Lévy Noise

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Acta Mathematica Sinica,English Series 2020年第4期36卷 443-461页

作者： Guang Jun SHEN qing bo WANG Xiu Wei YIN Department of Mathematics Anhui Normal UniversityWuhu 241000P.R.China

The statistical inference of the Vasicek model driven by small Levy process has a long *** this paper,we consider the problem of parameter estimation for Vasicek model dX_t=(μ-θX_t)dt+εdL_t^d,t∈[0,1],X_0=x_0,driven by small fractional Lévy noise with the known parameter d less than one half,based on discrete high-frequency observations at regularly spaced time points{t_i=i/n,i=1,2,...,n}.For the general case and the null recurrent case,the consistency as well as the asymptotic behavior of least squares estimation of unknown parametersμandθhave been established as small dispersion coefficientε→0 and large sample size n→∞simultaneously.

关键词： Ornstein–Uhlenbeck process fraction Lévy processes least squares estimator consistency asymptotic distribution

Calculating Method for Influence of Material Flow on Energy Consumption in Steel Manufacturing Process

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Journal of Iron and Steel Research International 2007年第2期14卷 46-51页

作者： YU qing-bo LU Zhong-wu CAI Jiu-ju School of Materials and Metallurgy Northeastern University Shenyang 110004 Liaoning China

From the viewpoint of systems energy conservation, the influences of material flow on its energy consumption in a steel manufacturing process is an important subject. The quantitative analysis of the relationship between material flow and the energy intensity is useful to save energy in steel industry. Based on the concept of standard material flow diagram, all possible situations of ferric material flow in steel manufacturing process are analyzed. The expressions of the influence of material flow deviated from standard material flow diagram on energy consumption are put forward.

关键词： steel manufacturing process material flow energy consumption calculating method