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Trifunctional strategy for the design and synthesis of a Ni-CeO_(2)@SiO_(2)catalyst with remarkable low-temperature sintering and coking resistance for methane dry reforming 被引量:6
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作者 Sixue Lin Jing Wang +5 位作者 Yangyang Mi Senyou Yang Zheng Wang Wenming Liu Daishe Wu Honggen Peng 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2021年第10期1808-1820,共13页
In this study,a trifunctional strategy was developed to prepare a confined Ni-based catalyst(Ni-CeO_(2)@SiO_(2))for dry reforming of methane(DRM)of two main greenhouse gases-CO_(2)and CH_(4).The Ni-CeO_(2)@SiO_(2)cata... In this study,a trifunctional strategy was developed to prepare a confined Ni-based catalyst(Ni-CeO_(2)@SiO_(2))for dry reforming of methane(DRM)of two main greenhouse gases-CO_(2)and CH_(4).The Ni-CeO_(2)@SiO_(2)catalyst was fabricated by utilizing the confinement effect of the SiO_(2)shell and the synergistic interaction between Ni-Ce and the decoking effect of CeO_(2).The catalysts were systematically characterized via X-ray diffraction,N_(2 )adsorption/desorption,transmission electron microscopy,energy dispersive X-ray spectroscopy,hydrogen temperature reduction and desorption set by program,oxygen temperature program desorption,Raman spectroscopy,thermogravimetric analysis,and in situ diffuse reflectance infrared Fourier transform spectroscopy measurements to reveal their physicochemical properties and reaction mechanism.The Ni-CeO_(2)@SiO_(2)catalyst exhibited higher activity and stability than the catalyst synthesized via the traditional impregnation method.In addition,no carbon deposition was detected over Ni-CeO_(2)@SiO_(2)after a 100 h durability test at 800℃,and the average particle size of Ni nanoparticles(NPs)in the catalyst increased from 5.01 to 5.77 nm.Remarkably,Ni-CeO_(2)@SiO_(2)also exhibited superior low-temperature stability;no coke deposition was observed when the catalyst was reacted at 600℃ for 20 h.The high coking and sintering resistance of this confined Ni-based DRM catalyst can be attributed to its trifunctional effect.The trifunctional strategy developed in this study could be used as a guideline to design other high-performance catalysts for CO_(2)and CH4 dry forming and accelerate their industrialization. 展开更多
关键词 Methane dry forming Low-temperature stability Coke resistance Tri functional strategy CO_(2)utilization
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Plasma spray forming of functionally graded materials mould
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作者 赵紫玉 方建成 李洪友 《中国有色金属学会会刊:英文版》 CSCD 2005年第2期427-431,共5页
A new technology of functionally graded materials(FGM) mould fabricated by plasma spraying and arc spraying was developed. According to applied characteristic of plastic mould, the reasonable coatings of FGM were desi... A new technology of functionally graded materials(FGM) mould fabricated by plasma spraying and arc spraying was developed. According to applied characteristic of plastic mould, the reasonable coatings of FGM were designed and their microstructures were analyzed. At the same time, some key problems were solved including spray mould fabricating, FGM forming and demoulding, etc. The results show that the service performance of the FGM mould is much more excellent than the one composed of the traditional materials, and the life span can also be greatly increased. The technology will have a significant influence on materials development in mould industry. 展开更多
关键词 溅射成型 功能分级材料 塑料模具 等离子体
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A two-grid algorithm based on Newton iteration for the stream function form of the Navier-Stokes equations 被引量:1
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作者 SHAO Xin-ping HAN Dan-fu 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2011年第3期368-378,共11页
In this paper, we propose a two-grid algorithm for solving the stream function formulation of the stationary Navies-Stokes equations. The algorithm is constructed by reducing the original system to one small, nonlinea... In this paper, we propose a two-grid algorithm for solving the stream function formulation of the stationary Navies-Stokes equations. The algorithm is constructed by reducing the original system to one small, nonlinear system on the coarse mesh space and two similar linear systems (with same stiffness matrix but different right-hand side) on the fine mesh space. The convergence analysis and error estimation of the algorithm are given for the case of conforming elements. Furthermore, the Mgorithm produces a numerical solution with the optimal asymptotic H^2-error. Finally, we give a numerical illustration to demonstrate the effectiveness of the two-grid algorithm for solving the Navier-Stokes equations. 展开更多
关键词 Two-grid algorithm Navier-Stokes equations Stream function form Reynolds number Newton iteration.
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Prediction of Forming Limit Diagrams for Materials with HCP Structure 被引量:1
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作者 Sheng-Hua Wu Nan-Nan Song +1 位作者 Francisco M.Andrade Pires Abel D.Santos 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2015年第12期1442-1451,共10页
The forming limit diagram(FLD) is an important tool to be used when characterizing the formability of metallic sheets used in metal forming processes. Experimental measurement and determination of the FLD is timecon... The forming limit diagram(FLD) is an important tool to be used when characterizing the formability of metallic sheets used in metal forming processes. Experimental measurement and determination of the FLD is timeconsuming and therefore the analytical prediction based on theory of plasticity and instability criteria allows a direct and efficient methodology to obtain critical values at different loading paths, thus carrying significant practical importance.However, the accuracy of the plastic instability prediction is strongly dependent on the choice of the material constitutive model [1–3]. Particularly for materials with hexagonal close packed(HCP) crystallographic structure, they have a very limited number of active slip systems at room temperature and demonstrate a strong asymmetry between yielding in tension and compression [4, 5]. Not only the magnitude of the yield locus changes, but also the shape of the yield surface is evolving during the plastic deformation [4]. Conventional phenomenological constitutive models of plasticity fail to capture this unconventional mechanical behavior [4, 6]. Cazacu and Plunkett [6] have proposed generic yield criteria, by using the transformed principal stress, to account for the initial plastic anisotropy and strength differential(SD) effect simultaneously. In this contribution, a generic FLD MATLAB script was developed based on Marciniak–Kuczynski analytical theory and applied to predict the localized necking. The influence of asymmetrical effect on the FLD was evaluated. Several yield functions such as von Mises, Hill, Barlat89, and Cazacu06 were incorporated into analysis. The paper also presents and discusses the influence of different hardening laws on the formability of materials with HCP crystal structures. The findings indicate that the plastic instability theory coupled with Cazacu model can adequately predict the onset of localized necking for HCP materials under different strain paths. 展开更多
关键词 forming limit diagram(FLD) Marciniak–Kuczynski analysis Plastic instability Yield function Hardening law
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Form and Function——An Overview
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作者 李艳 《海外英语》 2012年第18期228-229,共2页
Long before,the research of form has already entered its heyday,but the study of function is a somewhat new branch of language study.This essay is an attempt to take a brief look at the most significant distinction be... Long before,the research of form has already entered its heyday,but the study of function is a somewhat new branch of language study.This essay is an attempt to take a brief look at the most significant distinction between"form and function",and then aims at making clear the definition of"form and function"in discourse analysis. 展开更多
关键词 form function DISCOURSE ANALYSIS
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Application in metal rheological forming of element-free Galerkin method
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作者 罗迎社 殷水平 余敏 《Journal of Central South University》 SCIE EI CAS 2008年第S1期187-191,共5页
The element-free method is a new numerical technique presented in recent years.It uses the moving least square(MLS) approximation as its shape function,and it is determined by the basic function and weight function.Th... The element-free method is a new numerical technique presented in recent years.It uses the moving least square(MLS) approximation as its shape function,and it is determined by the basic function and weight function.The weight function is the mainly determining factor,so it greatly affects the accuracy of the computational results.The element-free Galerkin method(EFGM) was applied for the solution to plastic large deformation.The simulation of metal rheological forming was successfully done by programming and its results were visualized by using the plotting and data analyses software Tecplot.Then plastic strain under different stages during rheological forming and the three principal stresses at the last deformation were obtained.The example shows the feasibility of EFGM used for metal rheological forming and provides a new method for numerical simulation of rheological forming of complex parts. 展开更多
关键词 element-free GALERKIN method WEIGHT function RHEOLOGICAL forming NUMERICAL simulation
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A FORM FUNCTION METHOD FOR FORM FINDING OF TENSION STRUCTURE
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作者 孙宗光 赵俭斌 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2000年第11期1277-1281,共5页
A new form function involving parameters Pi is presented. On the basis of the form function, an initial form of tension structure was Sound by interpolating through the control points on boundary of the structure. The... A new form function involving parameters Pi is presented. On the basis of the form function, an initial form of tension structure was Sound by interpolating through the control points on boundary of the structure. The form function can be controlled by changing beta (1) according to the pre-tension and the boundary of the structure. The final form of a tension structure should be an equilibrium system under the pretension. To examine the nature of the initial form, the FEM was used. Many examples show that the initial form gives a very ideal result for equal or unequal pre-tension in two directions of the structure. In general cases, there is little difference between the initial form and the final one. 展开更多
关键词 tension structure form finding form function
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Multi-group pin power reconstruction method based on colorset form functions 被引量:1
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作者 HUANG Hao 《Nuclear Science and Techniques》 SCIE CAS CSCD 2009年第1期60-64,共5页
A multi-group pin power reconstruction method that fully exploits nodal information obtained from global coarse mesh solution has been developed.It expands the intra-nodal flux distributions into nonseparable semi-ana... A multi-group pin power reconstruction method that fully exploits nodal information obtained from global coarse mesh solution has been developed.It expands the intra-nodal flux distributions into nonseparable semi-analytic basis functions,and a colorset based form function generating method is proposed,which can accurately model the spectral interaction occurring at assembly interface.To demonstrate its accuracy and applicability to realistic problems, the new method is tested against two benchmark problems,including a mixed-oxide fuel problem.The results show that the new method is comparable in accuracy to fine-mesh methods. 展开更多
关键词 群组管理 LWR 二维多群辐射 输运过程 原子核
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TRANSFORMATION OF SYMMETRIC MULTIPLICATIVE FUNCTIONALS
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作者 AnHong YingJiangang 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2002年第4期451-457,共7页
In the present paper the transformation of symmetric Markov processes by symmetric martingale multiplicative functionals is studied and the corresponding Dirichlet form is formulated.
关键词 Markov processes Dirichlet forms multiplicative functional.
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A NON-INCREMENTAL TIME-SPACE ALGORITHM FOR NUMERICAL SIMULATION OF FORMING PROCESS
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作者 柳葆生 陈大鹏 刘渝 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1996年第11期1021-1029,共9页
A non-incremental time-space algorithm is proposed for numerical. analysis of forming process with the inclusion of geometrical, material, contact-frictional nonlinearities. Unlike the widely used Newton-Raphso... A non-incremental time-space algorithm is proposed for numerical. analysis of forming process with the inclusion of geometrical, material, contact-frictional nonlinearities. Unlike the widely used Newton-Raphson counterpart, the present scheme features an iterative solution procedure on entire time and space domain. Validity and feasibility of foe present scheme are further justiced by the numerical investigation herewith presented. 展开更多
关键词 forming process numerical simulation non-incremental algorithm time-space function
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A modeling approach for fuzzy programming with echelon form membership functions
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作者 WEN Bo LI HongGuang CHEN XiaoChun 《北京化工大学学报(自然科学版)》 CAS CSCD 北大核心 2018年第1期78-83,共6页
In order to solve fuzzy mathematical programming with soft constraints,the initial models must first be converted into crisp models.Membership functions are employed to describe the fuzzy right-hand side parameters ne... In order to solve fuzzy mathematical programming with soft constraints,the initial models must first be converted into crisp models.Membership functions are employed to describe the fuzzy right-hand side parameters needed to achieve this conversion.In some cases,echelon form membership functions(EFMFs)are required to depict the actual fuzzy situation.However,due to their discrete properties,fuzzy programming problems with such membership functions cannot be modeled by traditional methods.Motivated by these challenges,this paper introduces a novel absolute value representation modeling approach to formulate fuzzy programming using EFMFs.This approach can translate a discrete model to a continuous one which can then be easily solved.Finally,by means of a numerical example,the effectiveness of our new approach is demonstrated. 展开更多
关键词 echelon form membership function fuzzy right-hand side absolute value representation
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A NEW METHOD FOR ESTABLISHING PSEUDO ORTHOGONAL PROPERTIES OF EIGENFUNCTION EXPANSION FORM IN FRACTURE MECHANICS
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作者 OuZhuocheng ChenYiheng 《Acta Mechanica Solida Sinica》 SCIE EI 2004年第4期283-289,共7页
A new and simple method is developed to establish the pseudo orthogonal properties (POP) of the eigenfunction expansion form (EEF) of crack-tip stress complex potential functions for cracked anisotropic an... A new and simple method is developed to establish the pseudo orthogonal properties (POP) of the eigenfunction expansion form (EEF) of crack-tip stress complex potential functions for cracked anisotropic and piezoelectric materials, respectively. Di?erent from previous research, the complex argument separation technique is not required so that cumbersome manipulations are avoided. Moreover, it is shown, di?erent from the previous research too, that the orthogonal properties of the material characteristic matrices A and B are no longer necessary in obtaining the POP of EEF in cracked piezoelectric materials. Of the greatest signi?cance is that the method presented in this paper can be widely extended to treat many kinds of problems concerning path- independent integrals with multi-variables. 展开更多
关键词 eigenfunction expansion form pseudo orthogonal properties Bueckner integral weight function piezoelectric material anisotropic material
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RESIDUAL A POSTERIORI ERROR ESTIMATE TWO-GRID METHODS FOR THE STEADY (NAVIER-STOKES) EQUATION WITH STREAM FUNCTION FORM
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作者 任春风 马逸尘 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2004年第5期546-559,共14页
Residual based on a posteriori error estimates for conforming finite element solutions of incompressible Navier-Stokes equations with stream function form which were computed with seven recently proposed two-level met... Residual based on a posteriori error estimates for conforming finite element solutions of incompressible Navier-Stokes equations with stream function form which were computed with seven recently proposed two-level method were derived. The posteriori error estimates contained additional terms in comparison to the error estimates for the solution obtained by the standard finite element method. The importance of these additional terms in the error estimates was investigated by studying their asymptotic behavior. For optimal scaled meshes, these bounds are not of higher order than of convergence of discrete solution. 展开更多
关键词 two-level method Navier-Stokes equation residual a posteriori error estimate finite element method stream function form
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FORM AND FUNCTION OF EGYPTIAN BREAD MOLDS
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作者 Sheldon Lee Gosline 《Journal of Ancient Civilizations》 1999年第0期27-44,共18页
关键词 VI IV OK form AND function OF EGYPTIAN BREAD MOLDS
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Grand Zero Density Estimates of L-functions Associated with Cusp Forms
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作者 LI Ying-jie 《Chinese Quarterly Journal of Mathematics》 CSCD 2012年第1期79-86,共8页
In this paper a zero-density estimate of the large sieve type is given for the automorphic L-function L f (s,χ),where f is a holomorphic cusp form and χ a Dirichlet character of mod q.
关键词 zero density L-function cusp form
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A Sociolinguistic Study of Husband-to-Wife Address Forms and Functions in Rural Jordanian Community
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作者 Awni Shati M. Etaywe 《宏观语言学》 2017年第2期84-117,共34页
关键词 语言学 民族文化 文化传统 语用学
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Functional Enrichment of Utopian Distribution of Plant Life-Forms
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作者 James N. Furze Quanmin Zhu +1 位作者 Feng Qiao Jennifer Hill 《American Journal of Plant Sciences》 2013年第12期37-48,共12页
Adaptive fuzzy neural inference systems are used to illustrate the primary nodal number of plant life-forms. Categorization of two candidate areas is carried out using the water-energy dynamic (for Ecuador, South Amer... Adaptive fuzzy neural inference systems are used to illustrate the primary nodal number of plant life-forms. Categorization of two candidate areas is carried out using the water-energy dynamic (for Ecuador, South America) and Macedonia, Southern Europe), within which the life-form spectra are distributed. Genetic optimization methods are used to expand the primary nodal number to the complete number of life-form categories. The distribution of the elements exhibits a stochastic, binomial distribution and the utopia line and curve are summarized which enhance accuracy of the climatic data and of the consequent numbers of plant species occurrences. Expansion of the distribution of each life-form category is approximated within the Z utopia hyperplane with use of the functional approximation algorithm. This process gives additional structure and informative value to the Z plane, enhancing our ability to make informed policy decisions concerning species and ecosystem conservation. 展开更多
关键词 Adaptive Neural Fuzzy Inference System PLANT LIFE-form Genetic Optimization Stochastic UTOPIA functionAL Approximation Algorithm
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Systematic Benchmarking of Topology Optimization Methods Using Both Binary and Relaxed Forms of the Zhou-Rozvany Problem
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作者 Jiye Zhou Yun-Fei Fu Kazem Ghabraie 《Computer Modeling in Engineering & Sciences》 2025年第6期3233-3251,共19页
Most material distribution-based topology optimization methods work on a relaxed form of the optimization problem and then push the solution toward the binary limits.However,when benchmarking these methods,researchers... Most material distribution-based topology optimization methods work on a relaxed form of the optimization problem and then push the solution toward the binary limits.However,when benchmarking these methods,researchers use known solutions to only a single form of benchmark problem.This paper proposes a comparison platform for systematic benchmarking of topology optimization methods using both binary and relaxed forms.A greyness measure is implemented to evaluate how far a solution is from the desired binary form.The well-known ZhouRozvany(ZR)problem is selected as the benchmarking problem here,making use of available global solutions for both its relaxed and binary forms.The recently developed non-penalization Smooth-edged Material Distribution for Optimizing Topology(SEMDOT),well-established Solid Isotropic Material with Penalization(SIMP),and continuation methods are studied on this platform.Interestingly,in most cases,the grayscale solutions obtained by SEMDOT demonstrate better performance in dealing with the ZR problem than SIMP.The reasons are investigated and attributed to the usage of two different regularization techniques,namely,the Heaviside smooth function in SEMDOT and the power-law penalty in SIMP.More importantly,a simple-to-use benchmarking graph is proposed for evaluating newly developed topology optimization methods. 展开更多
关键词 Topology optimization Zhou-Rozvany problem BENCHMARKING binary forms relaxed forms power-law penalty heaviside smooth function
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同步发电机和非同步发电机电源接入强弱电网系统小扰动稳定特性比较与统一分析
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作者 刘琦 占萌 +1 位作者 李威 朱玲 《电工技术学报》 北大核心 2026年第1期182-200,共19页
同步发电机(SG)和跟网型变流器并网系统在弱电网下会存在稳定性问题,而构网型变流器并网系统在强电网下会存在稳定性问题,但对这三种电源接入电网后强弱电网失稳的特性缺少统一认识。为此,该文对SG和非SG电源并网系统的强弱电网小扰动... 同步发电机(SG)和跟网型变流器并网系统在弱电网下会存在稳定性问题,而构网型变流器并网系统在强电网下会存在稳定性问题,但对这三种电源接入电网后强弱电网失稳的特性缺少统一认识。为此,该文对SG和非SG电源并网系统的强弱电网小扰动失稳机理进行比较分析。首先,用特征值分析法对三种电源并网系统的同步环二阶模型和考虑外环(分别对应励磁调节和暂态电势、直流电压控制、端电压控制)的四阶模型的小扰动稳定性进行比较,确定了三种电源并网系统强弱电网失稳现象均与外环控制有关;其次,分别构建三种电源并网系统的类Heffron-Phillips模型,通过以同步环为主导环路、外环控制为附加支路的统一视角进行分析,基于反馈支路传递函数分解法,将三种电源并网系统不同结构的反馈传递函数G(s)分解为统一结构的二阶振荡环节H_(1)(s)和剩余环节H_(2)(s),统一分析系统强弱电网失稳的附加负阻尼转矩机理;最后,通过Matlab/Simulink仿真和硬件在环实验验证上述理论分析结果的有效性,并对SG和非SG电源接入强弱电网系统小扰动稳定的更加一般化统一认识加以讨论。 展开更多
关键词 同步发电机 构网型变流器 跟网型变流器 类Heffron-Phillips模型 反馈支路传递函数分解法
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New Formulation for Arbitrary Cracks Problem and Its Stress Intensity Factor of Plane Elasticity 被引量:4
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作者 杨晓春 范天佑 刘士强 《Journal of Beijing Institute of Technology》 EI CAS 1999年第4期364-369,共6页
Aim The general arbitrary cracked problem in an elastic plane was discussed. Methods For the purpose of acquiring the solution of the problem, a new formulation on the problem was proposed. Compared with the classic... Aim The general arbitrary cracked problem in an elastic plane was discussed. Methods For the purpose of acquiring the solution of the problem, a new formulation on the problem was proposed. Compared with the classical plane elastic crack model, only the known conditions were revised in the new formulation, which are greatly convenient to solve the problem, and no other new condition was given. Results and Conclusion The general exact analytic solution is given here based on the formulation though the problem is very complicated. Furthermore, the stress intensity factors K Ⅰ, K Ⅱ of the problem are also given. 展开更多
关键词 complex variable function method general curve cracks Riemann Hilbert boundary value problem closed form solution stress intensity factors
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