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Fenlong Cultivation-the Fourth Set of Farming Methods Invented in China 被引量:17
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作者 韦本辉 《Agricultural Science & Technology》 CAS 2017年第11期2045-2048,2052,共5页
The basic theory and effect of the new farming method of "Fenlong" cultivation which has been included in the main extension technology of Ministry of Agriculture of the People's Republic of China is fully illustra... The basic theory and effect of the new farming method of "Fenlong" cultivation which has been included in the main extension technology of Ministry of Agriculture of the People's Republic of China is fully illustrated for the first time, and it is the fourth set (generation) of farming modes and methods following manpower, animal and mechanical (tractor) farming. It follows the natural law to achieve soil activation, water saving, oxygen increase, warming and desalination through the active use of natural resources like soil, rainfall and solar energy, thereby promoting a new round of natural agricultural production and quality improvement and water con- servation, which has crop yield increase by 10%-30%, quality improvement of 5%, natural precipitation retaining increase by100%. The characteristics and mechanism are the use of spiral drill for one-time completion of the land preparation by drilling vertically to 30-50 cm of soil layer through high speed peeling. After instant high temperature and many fierce impacts, mechanical frictions, it could achieve the multiplication of the number of loose soil, soil physical modification and expansion of the soil nutrients, reservoirs, oxygen, microorganisms ("Four pools"). Fenlong cultivation can give birth to new farming culture and civilization, and it can achieve the physical "desalinized" transformation and utilization of saline soil. The formation of Fenlong green farming technology system makes it possible to invent the farming tools of "serf-propelled Fenlong machinery" that has got the patent, and it is the method for farmland (dry land, paddy field) Fenlong cultivation, saline-alkali soil smash-ridging cultivation and for the abundance of grass ecology on degraded grassland. The application of Fenlong "4+1" (arable, saline-alkali soil, grasslands, Sponge City+rivers) green development in China can achieve the "double safety" of food and living space. 展开更多
关键词 Fenlong cultivation The fourth set (generation) of new farming methods Activation and utilization of natural resources Improvement of production and quality Water conservation ecology
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Heat transfer study on solid and porous convective fins with temperature-dependent heat generation using efficient analytical method 被引量:10
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作者 S.E.Ghasemi P.Valipour +1 位作者 M.Hatami D.D.Ganji 《Journal of Central South University》 SCIE EI CAS 2014年第12期4592-4598,共7页
A simple and highly accurate semi-analytical method, called the differential transformation method(DTM), was used for solving the nonlinear temperature distribution equation in solid and porous longitudinal fin with t... A simple and highly accurate semi-analytical method, called the differential transformation method(DTM), was used for solving the nonlinear temperature distribution equation in solid and porous longitudinal fin with temperature dependent internal heat generation. The problem was solved for two main cases. In the first case, heat generation was assumed variable by fin temperature for a solid fin and in second heat generation varied with temperature for a porous fin. Results are presented for the temperature distribution for a range of values of parameters appearing in the mathematical formulation(e.g. N, εG, and G). Results reveal that DTM is very effective and convenient. Also, it is found that this method can achieve more suitable results in comparison to numerical methods. 展开更多
关键词 heat transfer convective fin solid and porous fin heat generation analytical method thermal analysis
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METHOD FOR ADAPTIVE MESH GENERATION BASED ON GEOMETRICAL FEATURES OF 3D SOLID 被引量:3
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作者 HUANG Xiaodong DU Qungui YE Bangyan 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2006年第3期330-334,共5页
In order to provide a guidance to specify the element size dynamically during adaptive finite element mesh generation, adaptive criteria are firstly defined according to the relationships between the geometrical featu... In order to provide a guidance to specify the element size dynamically during adaptive finite element mesh generation, adaptive criteria are firstly defined according to the relationships between the geometrical features and the elements of 3D solid. Various modes based on different datum geometrical elements, such as vertex, curve, surface, and so on, are then designed for generating local refined mesh. With the guidance of the defmed criteria, different modes are automatically selected to apply on the appropriate datum objects to program the element size in the local special areas. As a result, the control information of element size is successfully programmed covering the entire domain based on the geometrical features of 3D solid. A new algorithm based on Delatmay triangulation is then developed for generating 3D adaptive finite element mesh, in which the element size is dynamically specified to catch the geometrical features and suitable tetrahedron facets are selected to locate interior nodes continuously. As a result, adaptive mesh with good-quality elements is generated. Examples show that the proposed method can be successfully applied to adaptive finite element mesh automatic generation based on the geometrical features of 3D solid. 展开更多
关键词 Adaptive mesh generation Geometrical features Delaunay triangulation Finite element method
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Research on a toolpath generation method of NC milling based on space-filling curve
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作者 隋秀凛 Chen Xiaoqi +1 位作者 Ge Jianghua Jiao Yan 《High Technology Letters》 EI CAS 2017年第4期418-425,共8页
Tool path generated by space-filling curve always turns frequently causing trembling to machine,reducing toollife and affecting workpiece quality. Length and generation time of tool paths are both relatively long. In ... Tool path generated by space-filling curve always turns frequently causing trembling to machine,reducing toollife and affecting workpiece quality. Length and generation time of tool paths are both relatively long. In order to solve these problems,a toolpath generation method of NC milling based on space-filling curve is proposed. First,T-spline surface is regarded as the modeling surface,the grid,which is based on the limited scallop-height,can be got in the parameter space,and the influence value of grid node is determined. Second,a box is defined and planned,and the tool paths are got preliminarily,which is based on minimal spanning tree; Finally,based on an improved chamfering algorithm,the whole tool paths are got. A simulation system is developed for computer simulation,and an experiment is carried out to verify the method. The results of simulation and experiment show that the method is effective and feasible,and length and time of the tool paths are reduced. 展开更多
关键词 space-filling curve toolpath generation method NC milling T-spline surface minimal spanning tree
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NEW METHOD FOR GENERATION OF t-BUTYL PERFLUOROALKYL NITROXIDES
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作者 Cheng Xue ZHAO Yan Ling QU Huazhong University of Science and Technology,Department of Chemistry,Wuhan 430074Yi Yuan PENG Jiangxi Institute of Chemical Industry,Hanchang 330029 《Chinese Chemical Letters》 SCIE CAS CSCD 1992年第8期611-612,共2页
Electron transfer reactions between O-benzoyl t-butylhydroxyl- amine,t-BuNHOCOPh(1)and perfluorodiacyl peroxides(RfCO_2)_2(2)may serve as a novel method for generating useful t-hutyl perfluoroalkyl nitroxldes at room ... Electron transfer reactions between O-benzoyl t-butylhydroxyl- amine,t-BuNHOCOPh(1)and perfluorodiacyl peroxides(RfCO_2)_2(2)may serve as a novel method for generating useful t-hutyl perfluoroalkyl nitroxldes at room temperature in CFCl2-CF2Cl. 展开更多
关键词 In EPR CHEN NEW method FOR GENERATION OF t-BUTYL PERFLUOROALKYL NITROXIDES
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THREE-DIMENSIONAL FINITE ELEMENT DELAUNAY MESH GENERATION BY A PERFECTED NODE CONNECTION METHOD
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作者 Du Qungui 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2000年第2期153-158,共6页
How to automatically generate three-dimensional finite element Delaunay mesh by a peifected node connection method is introduced, where nodes are generated based on existing elements, instead of independence of node c... How to automatically generate three-dimensional finite element Delaunay mesh by a peifected node connection method is introduced, where nodes are generated based on existing elements, instead of independence of node creation and elements generation in traditional node connection method. Therefore, Ihe the difficulty about how to automatically create nodes in the traditional method is overcome. 展开更多
关键词 Finite element Mesh generation Delaunay triangulation Node connection method
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Wash Waves Generated by High Speed Displacement Ships
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作者 周利兰 高高 R.H.M.Huijsmans 《China Ocean Engineering》 SCIE EI CSCD 2015年第5期757-770,共14页
It is difficult to compute far-field waves in a relative large area by using one wave generation model when a large calculation domain is needed because of large dimensions of the waterway and long distance of the req... It is difficult to compute far-field waves in a relative large area by using one wave generation model when a large calculation domain is needed because of large dimensions of the waterway and long distance of the required computing points. Variation of waterway bathymetry and nonlinearity in the far field cannot be included in a ship fixed process either. A coupled method combining a wave generation model and wave propagation model is then used in this paper to simulate the wash waves generated by the passing ship. A NURBS-based higher order panel method is adopted as the stationary wave generation model; a wave spectrum method and Boussinesq-type equation wave model are used as the wave propagation model for the constant water depth condition and variable water depth condition, respectively. The waves calculated by the NURBS-based higher order panel method in the near field are used as the input for the wave spectrum method and the Boussinesq-type equation wave model to obtain the far-field waves. With this approach it is possible to simulate the ship wash waves including the effects of water depth and waterway bathymetry. Parts of the calculated results are validated experimentally, and the agreement is demonstrated. The effects of ship wash waves on the moored ship are discussed by using a diffraction theory method. The results indicate that the prediction of the ship induced waves by coupling models is feasible. 展开更多
关键词 wash waves wave generation model wave spectrum method Boussinesq type equation wave model motions of moored ship
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Exploration of High-Harmonic Generation from the CS2 Molecule by the Lewenstein Method in Two-Color Circularly Polarized Laser Field
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作者 张宏丹 郭静 +5 位作者 史岩 杜慧 刘海风 黄旭日 刘学深 景俊 《Chinese Physics Letters》 SCIE CAS CSCD 2017年第1期65-68,共4页
The high harmonic generation (HHG) from the CS<sub>2</sub> molecule in intense laser fields is investigated using the extended Lewenstein method. The initial state is the highest-occupied molecular orbital... The high harmonic generation (HHG) from the CS<sub>2</sub> molecule in intense laser fields is investigated using the extended Lewenstein method. The initial state is the highest-occupied molecular orbital of the CS<sub>2</sub> molecule, which can be well described by Gaussian wave packet using GAMESS-UK package. Compared with the case of the elliptical laser, the HHG can be extended in two-color circularly polarized laser field. The time-frequency analysis and classical electron trajectory as well as the ionization yield curve are also presented to further explain the underlying mechanism. After adding a static electric field on the z-direction, the single quantum path control is realized and the supercontinuum spectra are obtained. Moreover, an isolated 110 as pulse can be obtained by superposing the harmonics from 130th to 180th order. 展开更多
关键词 Exploration of High-Harmonic Generation from the CS2 Molecule by the Lewenstein method in Two-Color Circularly Polarized Laser Field CS
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Generation and Evolution of Cavitation Bubbles in Volume Alternate Cavitation(VAC)
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作者 Shangshuang Chen Yun Wang +4 位作者 Fuzhu Li Shenwei Xue Zhenying Xu Chao Yu Kun Zhang 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2023年第3期241-251,共11页
Cavitation generation methods have been used in multifarious directions because of their diversity,and numerous studies and discussions have been conducted on cavitation generation methods.This study aims to explore t... Cavitation generation methods have been used in multifarious directions because of their diversity,and numerous studies and discussions have been conducted on cavitation generation methods.This study aims to explore the generating mechanism and evolution law of volume alternate cavitation(VAC).In the VAC,liquid water is placed in an airtight container with a variable volume.As the volume alternately changes,the liquid water inside the container continues to cavitate.Then,the mixture turbulence model and in-cylinder dynamic grid model are adopted to conduct computational fluid dynamics simulation of volume alternate cavitation.In the simulation,the cloud images at seven heights on the central axis are monitored,and the phenomenon and mechanism of height and eccentricity are analyzed in detail.By employing the cavitation flow visualization method,the generating mechanism and evolution law of cavitation are revealed.The synergistic effects of experiments and high-speed camera capturing confirm the correctness of the simulation results.In the experiment,the volume change stroke of the airtight container is set to 20 mm,the volume change frequency is 18 Hz,and the shooting frequency of the high-speed camera is set to 10000 FPS.The experimental results indicate that the position of the cavitation phenomenon has a reasonable law during the whole evolution cycle of the cavitation cloud.Also,the volume alternation cycle corresponds to the generation,development,and collapse stages of cavitation bubbles. 展开更多
关键词 Cavitation generation method Volume alternate cavitation(VAC) Generating mechanism Evolution law Computational fluid dynamics(CFD) Cavitation flow visualization(CFV)
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A Survey on Adversarial Examples in Deep Learning 被引量:1
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作者 Kai Chen Haoqi Zhu +1 位作者 Leiming Yan Jinwei Wang 《Journal on Big Data》 2020年第2期71-84,共14页
Adversarial examples are hot topics in the field of security in deep learning.The feature,generation methods,attack and defense methods of the adversarial examples are focuses of the current research on adversarial ex... Adversarial examples are hot topics in the field of security in deep learning.The feature,generation methods,attack and defense methods of the adversarial examples are focuses of the current research on adversarial examples.This article explains the key technologies and theories of adversarial examples from the concept of adversarial examples,the occurrences of the adversarial examples,the attacking methods of adversarial examples.This article lists the possible reasons for the adversarial examples.This article also analyzes several typical generation methods of adversarial examples in detail:Limited-memory BFGS(L-BFGS),Fast Gradient Sign Method(FGSM),Basic Iterative Method(BIM),Iterative Least-likely Class Method(LLC),etc.Furthermore,in the perspective of the attack methods and reasons of the adversarial examples,the main defense techniques for the adversarial examples are listed:preprocessing,regularization and adversarial training method,distillation method,etc.,which application scenarios and deficiencies of different defense measures are pointed out.This article further discusses the application of adversarial examples which currently is mainly used in adversarial evaluation and adversarial training.Finally,the overall research direction of the adversarial examples is prospected to completely solve the adversarial attack problem.There are still a lot of practical and theoretical problems that need to be solved.Finding out the characteristics of the adversarial examples,giving a mathematical description of its practical application prospects,exploring the universal method of adversarial example generation and the generation mechanism of the adversarial examples are the main research directions of the adversarial examples in the future. 展开更多
关键词 Adversarial examples generation methods defense methods
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Pico–nano bubble column flotation using static mixer-venturi tube for Pittsburgh No.8 coal seam 被引量:9
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作者 Peng Felicia F. Yu Xiong 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2015年第3期347-354,共8页
The flotation process is a particle-hydrophobic surface-based separation technique. To improve the essential flotation steps of collision and attachment probabilities, and reduce the step of detachment probabilities b... The flotation process is a particle-hydrophobic surface-based separation technique. To improve the essential flotation steps of collision and attachment probabilities, and reduce the step of detachment probabilities between air bubbles and hydrophobic particles, a selectively designed cavitation venturi tube combined with a static mixer can be used to generate very high numbers of pico and nano bubbles in a flotation column. Fully embraced by those high numbers of tiny bubbles, hydrophobic particles readily attract the tiny bubbles to their surfaces. The results of column flotation of Pittsburgh No. 8 seam coal are obtained in a 5.08 cm ID and 162 cm height flotation column equipped with a static mixer and cavitation venturi tube, using kerosene as collector and MIBC as frother. Design of the experimental procedure is combined with a statistical two-stepwise analysis to determine the optimal operating conditions for maximum recovery at a specified grade. The effect of independent variables on the responses has been explained. Combustible material recovery of 85–90% at clean coal product of 10–11% ash is obtained from feed of 29.6% ash, with a much-reduced amount of frother and collector than that used in conventional column flotation. The column flotation process utilizing pico and nano bubbles can also be extended to the lower limit and upper limit of particle size ranges, minus 75 lm and 300–600 lm, respectively, for better recovery. 展开更多
关键词 Pico-nano bubble generation Cavitation venturi tube Fine coal flotation Statistical analysis method
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Data signal processing via manchester coding-decoding method using chaotic signals generated by PANDA ring resonator
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作者 I. S. Amiri J. Ali 《Chinese Optics Letters》 SCIE EI CAS CSCD 2013年第4期64-67,共4页
We investigate the nonlinear behaviors of light recognized as chaos during the propagation of Gaussian laser beam inside a nonlinear polarization maintaining and absorption reducing (PANDA) ring resonator system. It... We investigate the nonlinear behaviors of light recognized as chaos during the propagation of Gaussian laser beam inside a nonlinear polarization maintaining and absorption reducing (PANDA) ring resonator system. It aims to generate the nonlinear behavior of light to obtain data in binary logic codes for transmission in fiber optics communication. Effective parameters, such as refractive indices of a silicon waveguide, coupling coefficients (~), and ring radius ring (R), can be properly selected to operate the nonlinear behavior. Therefore, the binary coded data generated by the PANDA ring resonator system can be decoded and converted to Manchester codes, where the decoding process of the transmitted codes occurs at the end of the transmission link. The simulation results show that the original codes can be recovered with a high security of signal transmission using the Manchester method. 展开更多
关键词 ring Manchester Data signal processing via manchester coding-decoding method using chaotic signals generated by PANDA ring resonator
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The Feasibility Analysis of Delayed Retirement in Northwest China --Taking Gansu Province as an Example
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作者 ZHOU Zhou 《International English Education Research》 2017年第3期87-89,共3页
Gansu Province in the northwest of China, so the research on the impact of delay retirement in Gansu province have a certain representation. This paper analyzes the current situation of human resources in Gansu provin... Gansu Province in the northwest of China, so the research on the impact of delay retirement in Gansu province have a certain representation. This paper analyzes the current situation of human resources in Gansu province the proportion of the labor force is relatively low, the age structure of aging, education, human resources quality is still not high, the use of theoretical analysis method of overlapping generations model and AHP method to verify the proposed implementation. The delay retirement policy to increase the effective adjustment of Gansu province to improve the structure of human resources, better solve the problem of human resources structure in Gansu Province, so as to enhance Gansu's core competitive advantage. 展开更多
关键词 Delayed retirement: human resource structure overlapping generations model: AHP method
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Development of two-dimensional numerical wave tank based on lattice Boltzmann method 被引量:1
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作者 Guang-wei Liu Qing-he Zhang Jin-feng Zhang 《Journal of Hydrodynamics》 SCIE EI CSCD 2020年第1期116-125,共10页
A 2-D numerical wave tank(NWT)is developed using the lattice Boltzmann method(LBM)and a multi-relaxation-time(MRT)collision model coupled with an algebraic volume of fluid(VOF)scheme for free surface tracking.An exter... A 2-D numerical wave tank(NWT)is developed using the lattice Boltzmann method(LBM)and a multi-relaxation-time(MRT)collision model coupled with an algebraic volume of fluid(VOF)scheme for free surface tracking.An external force based on the momentum source function is used to generate the waves,and a zone of porous media is used to absorb the waves.Numerical simulations of the progressive and standing waves show that the NWT can generate stable wave trains in agreement with the analytical solutions and eliminate the re-reflection waves.The NWT is used to simulate two problems encountered in practice,namely:the wave transformation over a submerged breakwater and the wave runup on a sea dike.The numerical predictions are in good agreement with the measured data. 展开更多
关键词 Numerical wave tank(NWT) wave generation method volume of fluid(VOF) lattice Boltzmann method(LBM)
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A study on the random array generation method for moving sound source identification 被引量:1
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作者 WANG Yan LIU Zhihong +1 位作者 WU Bobo YI Chuijie 《Chinese Journal of Acoustics》 CSCD 2015年第3期283-296,共14页
Based on the problem that the generating method of random array structure is inefficient, a method is proposed to generate the random target arrays by using coaxial circu- lar array in the polar coordinates in the pre... Based on the problem that the generating method of random array structure is inefficient, a method is proposed to generate the random target arrays by using coaxial circu- lar array in the polar coordinates in the premise that the array angular resolution of source identification is guaranteed. According to the principle of moving sound source identification, this work deduces the basic non-equidistance coaxial circular rings' radius, and generates target random arrays which were suitable for moving sound source identification through array partitioning, condition filtering in the polar coordinates and simulation evaluation. Finally, numerical simulation and moving car sound source identification test have been done. The analytical results show that using this method to generate random array is effective. Compared with the traditional regular arrays, the target random array has more accurate moving sound source identification performance. 展开更多
关键词 A study on the random array generation method for moving sound source identification
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An approach for approximate solution of fractional-order smoking model with relapse class 被引量:1
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作者 Anwar Zeb Vedat Suat Erturk +2 位作者 Umar Khan Gul Zaman Shaher Momani 《International Journal of Biomathematics》 SCIE 2018年第6期31-57,共27页
In this paper, we develop a fractional-order smoking model by considering relapse class. First, we formulate the model and find the unique positive solution for the proposed model. Then we apply the Griinwald-Letnikov... In this paper, we develop a fractional-order smoking model by considering relapse class. First, we formulate the model and find the unique positive solution for the proposed model. Then we apply the Griinwald-Letnikov approximation in the place of maintaining a general quadrature formula approach to the Riemann-Liouville integral definition of the fractional derivative. Building on this foundation avoids the need for domain trans-formations, contour integration or involved theory to compute accurate approximate solutions of fractional-order giving up smoking model A comparative study between Griinwald-Letnikov method and Runge-Kutta method is presented in the case of integer-order derivative. Finally, we present the obtained results graphically. 展开更多
关键词 Mathematical model reproductive number next generation matrix method stability analysis Griinwald-Letnikov method numerical simulation.
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NUMERICAL SOLUTION OF DIFFERENTIAL EQUATIONS IN IRREGULAR PLANE REGIONS USING QUALITY STRUCTURED CONVEX GRIDS
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作者 F.DOM´INGUEZ-MOTA P.FERNANDEZ-VALDEZ +2 位作者 S.MENDOZA-ARMENTA G.TINOCO-GUERRERO J.G.TINOCO-RUIZ 《International Journal of Modeling, Simulation, and Scientific Computing》 EI 2013年第2期115-129,共15页
The variational grid generation method is a powerful tool for generating structured convex grids on irregular simply connected domains whose boundary is a polygonal Jordan curve.Several examples that show the accuracy... The variational grid generation method is a powerful tool for generating structured convex grids on irregular simply connected domains whose boundary is a polygonal Jordan curve.Several examples that show the accuracy of a finite difference approximation to the solution of a Poisson equation using this kind of structured grids have been recently reported.In this paper,we compare the accuracy of the numerical solution calculated using those structured grids and finite differences against the solution obtained with Delaunay-like triangulations on irregular regions. 展开更多
关键词 Numerical grid generation direct generation method finite difference method finite element method Delaunay triangulation.
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