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NORMAL STRUCTURE AND SOME GEOMETRIC PARAMETERS RELATED TO THE MODULUS OF U-CONVEXITY IN BANACH SPACES 被引量:2
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作者 Ji Gao Satit Saejung 《Acta Mathematica Scientia》 SCIE CSCD 2011年第3期1035-1040,共6页
We present a short and simple proof of the recent result of Yang and Wang [12]. Stimulated by their idea, two geometric parameters Uax(ε) and βx (ε), both related to Gao's modulus of U-convexity of a Banach sp... We present a short and simple proof of the recent result of Yang and Wang [12]. Stimulated by their idea, two geometric parameters Uax(ε) and βx (ε), both related to Gao's modulus of U-convexity of a Banach space X, are introduced. Their properties and the relationships with normal structure are studied. Some existing results involving normal structure and fixed points for non-expansive mappings in Banach spaces are improved. 展开更多
关键词 uniform normal structure modulus of convexity ULTRAPOWER
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Computer Aided Design Technology for Convex Faceted Gem Cuts Based on the Half-Edge Data Structure 被引量:1
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作者 Linhong Xu Xiangnan Li +3 位作者 Jianhua Rao Yuan Han Zhipeng Li Jichun Li 《Journal of Beijing Institute of Technology》 EI CAS 2019年第3期585-597,共13页
Aiming to increase the efficiency of gem design and manufacturing, a new method in computer-aided-design (CAD) of convex faceted gem cuts (CFGC) based on Half-edge data structure (HDS), including the algorithms for th... Aiming to increase the efficiency of gem design and manufacturing, a new method in computer-aided-design (CAD) of convex faceted gem cuts (CFGC) based on Half-edge data structure (HDS), including the algorithms for the implementation is presented in this work. By using object-oriented methods, geometrical elements of CFGC are classified and responding geometrical feature classes are established. Each class is implemented and embedded based on the gem process. Matrix arithmetic and analytical geometry are used to derive the affine transformation and the cutting algorithm. Based on the demand for a diversity of gem cuts, CAD functions both for free-style faceted cuts and parametric designs of typical cuts and visualization and human-computer interactions of the CAD system including two-dimensional and three-dimensional interactions have been realized which enhances the flexibility and universality of the CAD system. Furthermore, data in this CAD system can also be used directly by the gem CAM module, which will promote the gem CAD/CAM integration. 展开更多
关键词 Half-edge data structure convex faceted GEM CUTS (CFGC) COMPUTER aided design (CAD)
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EXISTENCE OF MULTIPLE SOLUTIONS FOR SINGULAR QUASILINEAR ELLIPTIC SYSTEM WITH CRITICAL SOBOLEV-HARDY EXPONENTS AND CONCAVE-CONVEX TERMS 被引量:6
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作者 李圆晓 高文杰 《Acta Mathematica Scientia》 SCIE CSCD 2013年第1期107-121,共15页
The main purpose of this paper is to establish the existence of multiple solutions for singular elliptic system involving the critical Sobolev-Hardy exponents and concave-convex nonlinearities. It is shown, by means o... The main purpose of this paper is to establish the existence of multiple solutions for singular elliptic system involving the critical Sobolev-Hardy exponents and concave-convex nonlinearities. It is shown, by means of variational methods, that under certain conditions, the system has at least two positive solutions. 展开更多
关键词 singular elliptic system concave-convex nonlinearities positive solution Nehari manifold critical Sobolev-Hardy exponent
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MULTIPLE POSITIVE SOLUTIONS FOR QUASILINEAR ELLIPTIC PROBLEMS INVOLVING CONCAVE-CONVEX NONLINEARITIES AND MULTIPLE HARDY-TYPE TERMS 被引量:3
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作者 Tsing-San HSU 《Acta Mathematica Scientia》 SCIE CSCD 2013年第5期1314-1328,共15页
In this paper, we deal with the existence and multiplicity of positive solutions for the quasilinear elliptic problem -△pu-∑i=1^kμi|u|^p-2/|x-ai|p^u=|u|^p^*-2u+λ|u|^q-2u,x∈Ω,where Ω belong to R^N(N ... In this paper, we deal with the existence and multiplicity of positive solutions for the quasilinear elliptic problem -△pu-∑i=1^kμi|u|^p-2/|x-ai|p^u=|u|^p^*-2u+λ|u|^q-2u,x∈Ω,where Ω belong to R^N(N ≥ 3) is a smooth bounded domain such that the different points ai∈Ω,i= 1,2,...,k,0≤μi〈μ^-=(N-p/p)^p,λ〉0,1≤q〈p,and p^*=p^N/N-p.The results depend crucially cn the parameters λ,q and μi for i=1,2,...,k. 展开更多
关键词 multiple positive solutions concave-convex nonlinearities multiple Hardy- type terms
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ON SEMILINEAR ELLIPTIC EQUATIONS WITH CONCAVE AND CONVEX NONLINEARITIES IN R^N
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作者 杨海涛 陈祖墀 《Acta Mathematica Scientia》 SCIE CSCD 2000年第2期181-188,共8页
In this paper, a class of semilinear elliptic equations with sublinear and superlinear nonlinearities in R-N is studied. By making use of variational method and L-infinity estimation, the authors obtain some results a... In this paper, a class of semilinear elliptic equations with sublinear and superlinear nonlinearities in R-N is studied. By making use of variational method and L-infinity estimation, the authors obtain some results about existence of multiple positive solutions and asymptotic behavior of the solutions. 展开更多
关键词 concave convex critical point asymptotic behavior
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ON A GENERALIZED MODULUS OF CONVEXITY AND UNIFORM NORMAL STRUCTURE
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作者 杨长森 王丰辉 《Acta Mathematica Scientia》 SCIE CSCD 2007年第4期838-844,共7页
In this article, the authors study a generalized modulus of convexity, δ(α) (ε). Certain related geometrical properties of this modulus are analyzed. Their main result is that Banach space X has uniform normal ... In this article, the authors study a generalized modulus of convexity, δ(α) (ε). Certain related geometrical properties of this modulus are analyzed. Their main result is that Banach space X has uniform normal structure if there exists ε, 0 ≤e≤ 1, such that δ^(α)(1+ε ) 〉 (1- α)ε. 展开更多
关键词 Generalized modulus of convexity uniform normal structure ULTRAPRODUCT
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COINCIDENCE POINT THEOREMS iN PROBABILISTIC METRIC SPACES WITH A CONVEX STRUCTURES
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作者 朴渭汰 朴根生 +1 位作者 赵烈济 金钟圭 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1994年第8期721-733,共13页
In lhis paper we draw some coincidence and common fixed point theorems fornonlinear hybrid contraction mappings on probabilistic metric spaces with a convexstructure.
关键词 probabilistic metric spaces a convex structure commuting mappings coincidence and common fixed points
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Simulation and Experimental Study on Improving Electrochemical Machining Stability of Highly Convex Structures on Casing Surfaces Using Backwater Pressure
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作者 Zhenghui Ge Wangwang Chen Yongwei Zhu 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2022年第4期152-158,共7页
Casing parts are regarded as key components of aero-engines.Most casing parts are attached to convex structures of diferent shapes,whose heights range from hundreds of microns to tens of millimeters.Using profling blo... Casing parts are regarded as key components of aero-engines.Most casing parts are attached to convex structures of diferent shapes,whose heights range from hundreds of microns to tens of millimeters.Using profling blocky electrodes for electrochemical machining(ECM)of casing parts is a commonly adopted method,especially when highly convex structures.However,with an increase in the convex structure height,the fow felds of the machining areas become more complex,and short circuits may occur at any time.In this study,a method to improve the fow feld characteristics within a machining area by adjusting the backwater pressure is proposed and validated through simulation and experiment analyses.The simulation results demonstrated that the back-pressure method can signifcantly improve the uniformity of the fow feld around the convex structure compared with the extraction and open outlet modes.Subsequently,the back-pressure value was optimized at 0.5 MPa according to the simulation results.The experimental results showed that using the optimized back-pressure parameters,the cathode feed-rate increased from 0.6 to 0.7 mm/min,and a 16.1 mm tall convex structure was successfully machined.This indicates that the back-pressure method is suitable and efective for electrochemical machining of highly convex structures with blocky electrodes.In this study,we propose a method to improve the electrochemical machining stability of a convex structure on a casing surface using backwater pressure,which has achieved remarkable results. 展开更多
关键词 Casing parts Electrochemical machining convex structures Back-pressure method Blocky electrode
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Existence of Positive Solutions to Semilinear Elliptic Systems Involving Concave and Convex Nonlinearities
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作者 Mohamed E1 Mokhtar ould El Mokhtar 《Journal of Physical Science and Application》 2015年第1期71-81,共11页
In this paper, we studied the combined effect of concave and convex nonlinearities on the number of positive solutions for a semilinear elliptic system. We prove the existence of at least four positive solutions for a... In this paper, we studied the combined effect of concave and convex nonlinearities on the number of positive solutions for a semilinear elliptic system. We prove the existence of at least four positive solutions for a semilinear elliptic system involving concave and convex nonlinearities by using the Nehari manifold and the center mass function. 展开更多
关键词 Elliptic systems concave and convex nonlinearities Nehari manifold maximum principle.
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Research on Optimizing Computer Network Structure based on Genetic Algorithm and Modified Convex Optimization Theory
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作者 Jinyu WANG 《International Journal of Technology Management》 2015年第7期95-97,共3页
In this paper, we report in-depth analysis and research on the optimizing computer network structure based on genetic algorithm and modified convex optimization theory. Machine learning method has been widely used in ... In this paper, we report in-depth analysis and research on the optimizing computer network structure based on genetic algorithm and modified convex optimization theory. Machine learning method has been widely used in the background and one of its core problems is to solve the optimization problem. Unlike traditional batch algorithm, stochastic gradient descent algorithm in each iteration calculation, the optimization of a single sample point only losses could greatly reduce the memory overhead. The experiment illustrates the feasibility of our proposed approach. 展开更多
关键词 Computer Network Genetic Algorithm convex Optimization structure Feature.
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Deployment Characteristics of Braid Coated Bi-Convex Tape and Bi-SMA Convex Tape Booms for Deployable Membrane Structures
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《Journal of Mechanics Engineering and Automation》 2014年第1期52-62,共11页
The purpose of this paper is to demonstrate and investigate the concepts of new deployable boom systems, which consist of the BCON (braid coated bi-convex tape) boom and the SMA-BCON (braid coated bi-shape memory a... The purpose of this paper is to demonstrate and investigate the concepts of new deployable boom systems, which consist of the BCON (braid coated bi-convex tape) boom and the SMA-BCON (braid coated bi-shape memory alloy convex tape) boom. Both booms are developed for the deployable membrane structures such as solar sails, thin membrane solar array panels, deorbit mechanisms for small satellites and reflectors of space solar power satellite, etc. BCON booms can store around polygonal or cylindrical center hub, and the booms can deploy by the stepwise manner by releasing a constraint mechanism which pins the boons into two or three points for the total length. SMA-BCON booms are mainly developed for a square center body systems, and SMA is adapted on the bent po^nts of the booms where stored around each edge of the center hub. Through the deployment experiments of both booms, the stepwise deployment behavior and its tendency are obtained. The design concept of BCON boom and SMA-BCON hnnm i~ demonstrated through this study. 展开更多
关键词 Braid coated bi-convex tape boom braid coated bi-SMA convex tape boom membrane structures.
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Multiple Solutions for a Class of Variable-Order Fractional Laplacian Equations with Concave-Convex Nonlinearity
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作者 Canlin Gan Ting Xiao Qiongfen Zhang 《Journal of Applied Mathematics and Physics》 2022年第3期837-849,共13页
This paper is concerned with the following variable-order fractional Laplacian equations , where N ≥ 1 and N > 2s(x,y) for (x,y) ∈ Ω × Ω, Ω is a bounded domain in R<sup>N</sup>, s(&#8901;)... This paper is concerned with the following variable-order fractional Laplacian equations , where N ≥ 1 and N > 2s(x,y) for (x,y) ∈ Ω × Ω, Ω is a bounded domain in R<sup>N</sup>, s(&#8901;) ∈ C (R<sup>N</sup> × R<sup>N</sup>, (0,1)), (-Δ)<sup>s(&#8901;)</sup> is the variable-order fractional Laplacian operator, λ, μ > 0 are two parameters, V: Ω → [0, ∞) is a continuous function, f ∈ C(Ω × R) and q ∈ C(Ω). Under some suitable conditions on f, we obtain two solutions for this problem by employing the mountain pass theorem and Ekeland’s variational principle. Our result generalizes the related ones in the literature. 展开更多
关键词 concave-convex Nonlinearity Variable-Order Fractional Laplacian Variational Methods Fractional Elliptic Equation
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A New Class of Banach Spaces with Uniform Normal Structure 被引量:6
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作者 高继 《Northeastern Mathematical Journal》 CSCD 2001年第1期103-110,共8页
Let X be a Banach space, S(X) be the unit sphere of X, φ be a function: S(X)→ S(X *) such that φ(x)∈ x, and v φ(ε) =inf 1-12x+y: x,y∈S(X), and 〈φ(x), x-y 〉≥ε, 0≤ε≤2, whe... Let X be a Banach space, S(X) be the unit sphere of X, φ be a function: S(X)→ S(X *) such that φ(x)∈ x, and v φ(ε) =inf 1-12x+y: x,y∈S(X), and 〈φ(x), x-y 〉≥ε, 0≤ε≤2, where x is the set of norm 1 supporting functionals of S(X) at x. A geometric concept, modulus of V convexity V(ε)= sup {V φ(ε), for all φ: S(X)→S(X *)}, is introduced; the properties of V(ε) and the relationship between V(ε) and other geometric concepts are discussed. The main result is that V12>0 implies normal structure. 展开更多
关键词 normal structure modulus of convexity modulus of V convexity uniformly nonsquare uniformly convex uniformly smooth V space
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Structural eigenvalue analysis under the constraint of a fuzzy convex set model 被引量:1
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作者 Wencai Sun Zichun Yang Guobing Chen 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2018年第4期653-666,共14页
In small-sample problems, determining and controlling the errors of ordinary rigid convex set models are difficult. Therefore, a new uncertainty model called the fuzzy convex set(FCS) model is built and investigated... In small-sample problems, determining and controlling the errors of ordinary rigid convex set models are difficult. Therefore, a new uncertainty model called the fuzzy convex set(FCS) model is built and investigated in detail. An approach was developed to analyze the fuzzy properties of the structural eigenvalues with FCS constraints. Through this method, the approximate possibility distribution of the structural eigenvalue can be obtained. Furthermore, based on the symmetric F-programming theory, the conditional maximum and minimum values for the structural eigenvalue are presented, which can serve as nonfuzzy quantitative indicators for fuzzy problems. A practical application is provided to demonstrate the practicability and effectiveness of the proposed methods. 展开更多
关键词 structural eigenvalue FUZZY convex set Conditional extreme Symmetric F-programming
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3D stability analysis method of concave slope based on the Bishop method 被引量:6
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作者 Zhang Tianwen Cai Qingxiang +2 位作者 Han Liu Shu Jisen Zhou Wei 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2017年第2期365-370,共6页
In order to study the stability control mechanism of a concave slope with circular landslide, and remove the influence of differences in shape on slope stability, the limit analysis method of a simplified Bishop metho... In order to study the stability control mechanism of a concave slope with circular landslide, and remove the influence of differences in shape on slope stability, the limit analysis method of a simplified Bishop method was employed. The sliding body was divided into strips in a three-dimensional model, and the lateral earth pressure was put into mechanical analysis and the three-dimensional stability analysis methods applicable for circular sliding in concave slope were deduced. Based on geometric structure and the geological parameters of a concave slope, the influence rule of curvature radius and the top and bottom arch height on the concave slope stability were analyzed. The results show that the stability coefficient decreases after growth, first in the transition stage of slope shape from flat to concave, and it has been confirmed that there is a best size to make the slope stability factor reach a maximum. By contrast with average slope, the stability of a concave slope features a smaller range of ascension with slope height increase, which indicates that the enhancing effect of a concave slope is apparent only with lower slope heights. 展开更多
关键词 Bishop method concave slope Three-dimensional structure Stability analysis
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A NEW METHOD FOR THE UNCERTAIN RESPONSE ANALYSIS OF STRUCTURES WITH UNCERTAIN PARAMETERS 被引量:1
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作者 Xie Jun Sun Yan Guan Gang 《Acta Mechanica Solida Sinica》 SCIE EI 2003年第1期47-51,共5页
A computing method for estimating the upper and lower bounds of the response of structures with uncertainties is presented. The uncertain parameters are described by the convex model. A numerical example of the frame ... A computing method for estimating the upper and lower bounds of the response of structures with uncertainties is presented. The uncertain parameters are described by the convex model. A numerical example of the frame structure is given to illustrate the effectiveness of this method. 展开更多
关键词 convex model structures with uncertainties upper and lower bounds of response
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Structured Sparse Coding With the Group Log-regularizer for Key Frame Extraction 被引量:1
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作者 Zhenni Li Yujie Li +2 位作者 Benying Tan Shuxue Ding Shengli Xie 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2022年第10期1818-1830,共13页
Key frame extraction based on sparse coding can reduce the redundancy of continuous frames and concisely express the entire video.However,how to develop a key frame extraction algorithm that can automatically extract ... Key frame extraction based on sparse coding can reduce the redundancy of continuous frames and concisely express the entire video.However,how to develop a key frame extraction algorithm that can automatically extract a few frames with a low reconstruction error remains a challenge.In this paper,we propose a novel model of structured sparse-codingbased key frame extraction,wherein a nonconvex group log-regularizer is used with strong sparsity and a low reconstruction error.To automatically extract key frames,a decomposition scheme is designed to separate the sparse coefficient matrix by rows.The rows enforced by the nonconvex group log-regularizer become zero or nonzero,leading to the learning of the structured sparse coefficient matrix.To solve the nonconvex problems due to the log-regularizer,the difference of convex algorithm(DCA)is employed to decompose the log-regularizer into the difference of two convex functions related to the l1 norm,which can be directly obtained through the proximal operator.Therefore,an efficient structured sparse coding algorithm with the group log-regularizer for key frame extraction is developed,which can automatically extract a few frames directly from the video to represent the entire video with a low reconstruction error.Experimental results demonstrate that the proposed algorithm can extract more accurate key frames from most Sum Me videos compared to the stateof-the-art methods.Furthermore,the proposed algorithm can obtain a higher compression with a nearly 18% increase compared to sparse modeling representation selection(SMRS)and an 8% increase compared to SC-det on the VSUMM dataset. 展开更多
关键词 Difference of convex algorithm(DCA) group logregularizer key frame extraction structured sparse coding
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Filtering algorithm of line structured light for long-distance obstacle detection
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作者 邵海燕 张振海 李科杰 《Journal of Beijing Institute of Technology》 EI CAS 2016年第4期521-525,共5页
Since unmanned ground vehicles often encounter concave and convex obstacles in wild ground, a filtering algorithm using line structured light to detect these long distance obstacles is proposed. For the line structure... Since unmanned ground vehicles often encounter concave and convex obstacles in wild ground, a filtering algorithm using line structured light to detect these long distance obstacles is proposed. For the line structured light image, a ranked-order based adaptively extremum median (RAEM) filter algorithm on salt and pepper noise is presented. In the algorithm, firstly effective points and noise points in a filtering window are differentiated; then the gray values of noise points are replaced by the medium of gray values of the effective pixels, with the efficient points' gray values unchanged; in the end this algorithm is proved to be efficient by experiments. Experimental resuits demonstrate that the image blur, resulting into proposed algorithm can remove noise points effectively and minimize the protecting the edge information as much as possible. 展开更多
关键词 unmanned ground vehicles line structured light concave and convex obstacles detec-tion ranked-order based adaptively extremum median (RAEM) filter filter algorithm
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Flame Structure of Methane and Kerosene Combustion with a Compact Concave Flame-Holder using the LES-pdf Method 被引量:1
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作者 WANG Fang WANG Yunfan +3 位作者 WEI Guanyi LIU Denghuan JIN Jie JONES P.William 《Journal of Thermal Science》 SCIE EI CSCD 2024年第1期222-234,共13页
Compact flame-holders for afterburners are an increasing requirement for modern aero engines.However,flame-holder design is non-trivial since high inlet temperatures,velocities,and elaborate structures induce complex ... Compact flame-holders for afterburners are an increasing requirement for modern aero engines.However,flame-holder design is non-trivial since high inlet temperatures,velocities,and elaborate structures induce complex turbulence,combustion,and spray coupling in modern afterburners.In this work,the LES-pdf and stochastic fields-Lagrangian particle spray methods are used to investigate methane and aviation kerosene combustion structures formed by new-type concave flame-holders.The flow pattern,combustion mode,and flame structure of gaseous and liquid fuel around a concave flame-holder are analyzed,discussed,and compared with experimental results.Results reveal that the flame stability of a concave flame-holder is better than that of the non-concave one.Furthermore,when using liquid fuel,the concave flame-holder forms a stable and compact flame.These results suggest concave flame-holders are a promising design for compact afterburners. 展开更多
关键词 concave structure flame-holder LES-pdf spray combustion flame structure AECSC
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ON A CLASS OF KTHE SEQUENCE SPACES WITH NORMAL STRUCTURE
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作者 B. Zlatanov 《Acta Mathematica Scientia》 SCIE CSCD 2011年第2期576-590,共15页
In this note, we investigate the generalized modulus of convexity δ(λ) and the generalized modulus smoothness p(λ). We obtain some estimates of these moduli for X=lp. We obtain inequalities between WCS coeffici... In this note, we investigate the generalized modulus of convexity δ(λ) and the generalized modulus smoothness p(λ). We obtain some estimates of these moduli for X=lp. We obtain inequalities between WCS coefficient of a KSthe sequence space X and δX(λ). We show that, for a wide class of class the sequence spaces X, if for some ε∈(0, 9/10] holds δx(e) 〉 1/3(1- √3/2)ε, then X has normal structure. 展开更多
关键词 Weakly convergent sequence coefficient modulus of convexity generalizedmodulus of convexity normal structure
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