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浅谈多线螺纹(或多头蜗杆)的分线方法
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作者 杨宏寅 《科技风》 2008年第20期39-39,41,共2页
沿两条或两条以上的在轴向等距分布的螺旋线所形成的螺纹或蜗杆称为多线螺纹或多头蜗杆。机械加工中常会遇到多线螺纹(或多头蜗杆),对于车削多线螺纹(蜗杆)时存在的分线问题,应从实际出发,找准齿轮卡尺测量的方法,找到精车时需要车削的... 沿两条或两条以上的在轴向等距分布的螺旋线所形成的螺纹或蜗杆称为多线螺纹或多头蜗杆。机械加工中常会遇到多线螺纹(或多头蜗杆),对于车削多线螺纹(蜗杆)时存在的分线问题,应从实际出发,找准齿轮卡尺测量的方法,找到精车时需要车削的侧面。 展开更多
关键词 多线螺纹 多头蜗杆 分线方法
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多线蜗杆车削方法分析和应用
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作者 孙丽霞 《教育教学论坛》 2013年第13期211-212,227,共3页
蜗杆的齿形与梯形螺纹相似,但蜗杆为普通传动零件,与蜗轮啮合传动,它的各部分尺寸计算有其特殊的要求,通过对多线蜗杆加工中的分线方法和分线精度分析,克服加工过程中碰到的困难,弄清注意事项,提高分线技巧和加工精度,从而提高车削水平... 蜗杆的齿形与梯形螺纹相似,但蜗杆为普通传动零件,与蜗轮啮合传动,它的各部分尺寸计算有其特殊的要求,通过对多线蜗杆加工中的分线方法和分线精度分析,克服加工过程中碰到的困难,弄清注意事项,提高分线技巧和加工精度,从而提高车削水平和加工精度。 展开更多
关键词 多线蜗杆车削 分线方法 分线精度
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特殊多线螺纹的快速轴向分线法
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作者 岳云斌 《河南科技》 2014年第7期110-111,共2页
本文通过对特殊多线螺纹的快速轴向分线法的教学分析、例题进行验证,采用快速轴向分线法进行操作帮助学生克服加工过程中碰到的困难,弄清注意事项,提高分线技巧和加工精度,从而降低劳动强度,节约时间并能保证零件的分线精度、简化操作,... 本文通过对特殊多线螺纹的快速轴向分线法的教学分析、例题进行验证,采用快速轴向分线法进行操作帮助学生克服加工过程中碰到的困难,弄清注意事项,提高分线技巧和加工精度,从而降低劳动强度,节约时间并能保证零件的分线精度、简化操作,在实践中具有很好的实用意义。 展开更多
关键词 多线螺纹 丝杆的螺距精度 特殊分线方法 快速轴向分线
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特殊多线螺纹的快速轴向分线法
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作者 陆为贞 《中国现代教育装备》 2011年第16期27-27,共1页
多线螺纹(蜗杆)的各螺旋槽在轴向是等距分布的,在端面上螺旋的起点是等角分布的,在车削过程中,解决等距分布的方法叫分线。如果分线出现误差,就会使所车出的多线螺纹螺距不等,从而严重影响内外螺纹的配合精度、降低使用寿命,甚至造成... 多线螺纹(蜗杆)的各螺旋槽在轴向是等距分布的,在端面上螺旋的起点是等角分布的,在车削过程中,解决等距分布的方法叫分线。如果分线出现误差,就会使所车出的多线螺纹螺距不等,从而严重影响内外螺纹的配合精度、降低使用寿命,甚至造成无法安装使用。由此可以看出,车削多线螺纹(蜗杆)时,采取正确的分线方法、 展开更多
关键词 多线螺纹 轴向 车削 分线方法
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数控机床多线螺纹加工技术探析 被引量:2
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作者 杨小英 《数字技术与应用》 2012年第4期268-268,共1页
系统地介绍了车刀的选择、车刀角度的计算,车刀的安装技巧和多线螺纹中螺距以及主轴转速的计算方法;对多线螺纹加工中分线问题,做了详细的介绍,提供了了圆周分线法以及轴向分线法的实际操作技巧。同时,给出了直线式切削法和斜进式切削... 系统地介绍了车刀的选择、车刀角度的计算,车刀的安装技巧和多线螺纹中螺距以及主轴转速的计算方法;对多线螺纹加工中分线问题,做了详细的介绍,提供了了圆周分线法以及轴向分线法的实际操作技巧。同时,给出了直线式切削法和斜进式切削法两个加工进给方法的操作要领,并对其优缺点做了对比。此外,还介绍了多线螺纹分线误差的修正方法。为生产加工多线螺纹提供参考,为减少错误操作、提高产品质量及生产效率提供切实可行的借鉴。 展开更多
关键词 多线螺纹 参数设置 分线方法 进给方式 分线误差修正
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三线梯形螺纹的切削加工 被引量:1
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作者 郑绍芸 《机电工程技术》 2007年第12期39-40,96,共3页
加工多线螺纹的难点在于如何提高粗车速度,精车精度。本文通过三线梯形螺纹加工实例,介绍了车削三线梯形螺纹时,采用宽刃刀进行快速分头,强力双刀进行粗车;采用百分表配合小滑板精确分线后进行精车,从而保证梯形螺纹牙形精度的方法。
关键词 三线梯牙 分线方法 宽刃刀 牙形精度
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SOLVABILITY RESULTS OF A CONDITIONAL INPUT-OUTPUT EQUATION BASED ON A TYPE OF NONLINEAR LEONTIEF MODEL
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作者 胡问鸣 刘颖范 沙春林 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2003年第2期224-229,共6页
A class of nonlinear and continuous type Leontief model and its corresponding conditional input-output equation are introduced, and two basic problems under the so called positive or negative boundary assumption are p... A class of nonlinear and continuous type Leontief model and its corresponding conditional input-output equation are introduced, and two basic problems under the so called positive or negative boundary assumption are presented. By approaches of nonlinear analysis some solvability results of this equation and continuous perturbation properties of the relative solution sets are obtained, and some economic significance are illustrated by the remark. 展开更多
关键词 conditional Leontief model input-output equation positive (negative) boundary assumption nonlinear analysis SOLVABILITY continuous disturbance
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Calculation and Analysis of Near Field of Airborne Short Wave Antenna
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作者 薛正辉 高本庆 +2 位作者 刘瑞祥 吕昕 杨力 《Journal of Beijing Institute of Technology》 EI CAS 1998年第3期286-292,共7页
Aim To calculate and analyze the near field distribution of ariborne short wave antenna. Methods B-spline method was used to get the mathermatital model of a Boeing 707320Baircraft and simulate its short wave antenna ... Aim To calculate and analyze the near field distribution of ariborne short wave antenna. Methods B-spline method was used to get the mathermatital model of a Boeing 707320Baircraft and simulate its short wave antenna . FDTD (finite-difference time-domain) method are ed tO complete the calculation and analysis. Results The near field distributions on aircraft's surface were obtained, the curve and gray figures of the normalized near field value were shown. Conclusion These modeling and calculating methods can provide data foraircraft's EMC analysis and design. 展开更多
关键词 airborne short antenna near field distribution FDTD method B-SPLINE
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外三线梯形螺纹的车削加工 被引量:1
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作者 陈杏 《机械工程师》 2017年第6期145-146,共2页
在普通车床上加工外三线梯形螺纹,如何保证既高效又高质量是一个难点。文中综合具体实例介绍了一种先采用焊接硬质合金车刀进行高速粗加工,再用高速钢精车刀进行低速精加工的方法,可保证多线螺纹的加工效率及精度,对生产实践具有较好的... 在普通车床上加工外三线梯形螺纹,如何保证既高效又高质量是一个难点。文中综合具体实例介绍了一种先采用焊接硬质合金车刀进行高速粗加工,再用高速钢精车刀进行低速精加工的方法,可保证多线螺纹的加工效率及精度,对生产实践具有较好的指导作用。 展开更多
关键词 外三线梯形螺纹 高速粗车 低速精车 分线方法及精度
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Multi-scale Chaotic Analysis of the Characteristics of Gas-Liquid Two-phase Flow Patterns 被引量:5
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作者 李洪伟 周云龙 +1 位作者 孙斌 杨悦 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2010年第5期880-888,共9页
Using the high-speed camera the time sequences of the classical flow patterns of horizontal gas-liquid pipe flow are recorded, from which the average gray-scale values of single-frame images are extracted. Thus obtain... Using the high-speed camera the time sequences of the classical flow patterns of horizontal gas-liquid pipe flow are recorded, from which the average gray-scale values of single-frame images are extracted. Thus obtained gray-scale time series is decomposed by the Empirical Mode Decomposition (EMD) method, the various scales of the signals are processed by Hurst exponent method, and then the dual-fractal characteristics are obtained. The scattered bubble and the bubble cluster theories are applied to the evolution analysis of two-phase flow patterns. At the same time the various signals are checked in the chaotic recursion chart by which the two typical characteristics (diagonal average length and Shannon entropy) are obtained. Resulting term of these properties, the dynamic characteristics of gas-liquid two-phase flow patterns are quantitatively analyzed. The results show that the evolution paths of gas-liquid two-phase flow patterns can be well characterized by the integrated analysis on the basis of the gray-scale time series of flowing images from EMD, Hurst exponents and Recurrence Plot (RP). In the middle frequency section (2nd, 3rd, 4th scales), three flow patterns decomposed by the EMD exhibit dual fractal characteristics which represent the dynamic features of bubble cluster, single bubble, slug bubble and scattered bubble. According to the change of diagonal average lengths and recursive Shannon entropy characteristic value, the structure deterministic of the slug flow is better than the other two patterns. After the decomposition by EMD the slug flow and the mist flow in the high frequency section have obvious peaks. Anyway, it is an effective way to understand and characterize the dynamic characteristics of two-phase flow patterns using the multi-scale non-linear analysis method based on image gray-scale fluctuation signals. 展开更多
关键词 gas-liquid two-phase flow gray-scale time series empirical mode decomposition Hurst exponent chaotic recurrence plot
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Linearity optimization of edge filter demodulators in FBG_s 被引量:2
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作者 LI Dong-sheng SUI Qing-mei CAO Yu-qiang 《Optoelectronics Letters》 EI 2008年第3期193-195,共3页
A kind of electric circuit is improved to optimize the linearity of edge filter demodulators in FBG .By using a logarithm amplifier and an extraction operation, the linear range of optimized edge filter demodulators h... A kind of electric circuit is improved to optimize the linearity of edge filter demodulators in FBG .By using a logarithm amplifier and an extraction operation, the linear range of optimized edge filter demodulators has been broadened effectively, and the requirement of optical filter's linear range has been reduced. Theoretical analyses and the simulation results indi-cated that the linear range of optimized edge fdter demodulator's covers the whole transition region of the edge filter, while a strict linearity of the optical filter is not necessary. 展开更多
关键词 光纤 解调器 线性分析 分析方法
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Exact Solutions Expressible in Rational Formal Hyperbolic and Elliptic Functions for Nonlinear Differential-Difference Equation 被引量:3
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作者 BAI Cheng-Jie ZHAO Hong HAN Ji-Guang 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第8期303-308,共6页
A new approach is presented by means of a new general ansitz and some relations among Jacobian elliptic functions, which enables one to construct more new exact solutions of nonlinear differential-difference equations... A new approach is presented by means of a new general ansitz and some relations among Jacobian elliptic functions, which enables one to construct more new exact solutions of nonlinear differential-difference equations. As an example, we apply this new method to Hybrid lattice, diseretized mKdV lattice, and modified Volterra lattice. As a result, many exact solutions expressible in rational formal hyperbolic and elliptic functions are conveniently obtained with the help of Maple. 展开更多
关键词 nonlinear differential-difference equations new approach exact solutions
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Modelling of ultrasonic motor with dead-zone based on Hammerstein model structure 被引量:9
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作者 Xin-liang ZHANG Yong-hong TAN 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2008年第1期58-64,共7页
The ultrasonic motor (USM) possesses heavy nonlinearities which vary with driving conditions and load-dependent characteristics such as the dead-zone. In this paper, an identification method for the rotary travelling-... The ultrasonic motor (USM) possesses heavy nonlinearities which vary with driving conditions and load-dependent characteristics such as the dead-zone. In this paper, an identification method for the rotary travelling-wave type ultrasonic motor (RTWUSM) with dead-zone is proposed based on a modified Hammerstein model structure. The driving voltage contributing effect on the nonlinearities of the RTWUSM was transformed to the change of dynamic parameters against the driving voltage. The dead-zone of the RTWUSM is identified based upon the above transformation. Experiment results showed good agreement be- tween the output of the proposed model and actual measured output. 展开更多
关键词 Ultrasonic motor (USM) Hammerstein model DEAD-ZONE NONLINEARITY IDENTIFICATION
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Interaction Between Line Soliton and Algebraic Soliton for Asymmetric Nizhnik-Novikov-Veselov Equation 被引量:1
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作者 RUAN Hang-Yu LI Zhi-Fang 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第6期1547-1552,共6页
Starting from the variable separation approach, the algebraic soliton solution and the solution describing the interaction between line soliton and algebraic soliton are obtained by selecting appropriate seed solution... Starting from the variable separation approach, the algebraic soliton solution and the solution describing the interaction between line soliton and algebraic soliton are obtained by selecting appropriate seed solution for (2+1)-dimensional ANNV equation. The behaviors of interactions are discussed in detail both analytically and graphically. It is shown that there are two kinds of singular interactions between line soliton and algebraic soliton: 1) the resonant interaction where the algebraic soliton propagates together with the line soliton and persists infinitely; 2) the extremely repulsive interaction where the algebraic soliton affects the motion of the line soliton infinitely apart. 展开更多
关键词 variable separation approach the interaction between line soliton and algebraic soliton (2+1)-dimensional ANNV equation
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Quasi-Classical Trajectory Study on O++DH(v=0,j=0)→OD++H Reaction at Different Collision Energy
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作者 孙海竹 刘新国 +1 位作者 吕娟娟 刘会荣 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2010年第5期521-526,621,共7页
The quasi-classical trajectory calculations O++DH(v=0,j=0)→OD++H reactions on the RODRIGO potential energy surface have been carried out to study the isotope effect on stereo-dynamics at the collision energies ... The quasi-classical trajectory calculations O++DH(v=0,j=0)→OD++H reactions on the RODRIGO potential energy surface have been carried out to study the isotope effect on stereo-dynamics at the collision energies of 1.0, 1.5, 2.0, and 2.5 eV. The distributions of dihedral angle P(~r) and the distributions of P(Or) are discussed. Furthermore, the angular distributions of the product rotational vectors in the form of polar plot in θr and φr are calculated. The differential cross section shows interesting phenomenon that the reaction is dominated by the direct reaction mechanism. Reaction probability and reaction cross section are also calculated. The calculations indicate that the stereo-dynamics properties of the title reactions are sensitive to the collision energy. 展开更多
关键词 Stereo-dynamics Quasi-classical trajectory method Polarization-dependentdifferential cross-section
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Ground states for asymptotically periodic quasilinear Schrdinger equations with critical growth
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作者 张慧 张福保 《Journal of Southeast University(English Edition)》 EI CAS 2013年第3期352-354,共3页
For a class of asymptotically periodic quasilinear Schr?dinger equations with critical growth the existence of ground states is proved.First applying a change of variables the quasilinear Schr?dinger equations are r... For a class of asymptotically periodic quasilinear Schr?dinger equations with critical growth the existence of ground states is proved.First applying a change of variables the quasilinear Schr?dinger equations are reduced to semilinear Schr?dinger equations in which the corresponding functional is well defined in H1 RN .Moreover there is a one-to-one correspondence between ground states of the semilinear Schr?dinger equations and the quasilinear Schr?dinger equations.Then the mountain-pass theorem is used to find nontrivial solutions for the semilinear Schr?dinger equations. Finally under certain monotonicity conditions using the Nehari manifold method and the concentration compactness principle the nontrivial solutions are found to be exactly the same as the ground states of the semilinear Schr?dinger equations. 展开更多
关键词 quasilinear Schrodinger equation variationalmethod ground state critical growth
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Separation of chalcopyrite and pyrite from a copper tailing by ammonium humate 被引量:8
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作者 Cuicui Lü Yongliang Wang +5 位作者 Peng Qian Ya Liu Guoyan Fu Jian Ding Shufeng Ye Yuanfa Chen 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2018年第9期1814-1821,共8页
Copper tailings constitute a large proportion of mine wastes. Some of the copper tailings can be recycled to recover valuable minerals. In this paper, a copper tailing was studied through the chemical analysis method,... Copper tailings constitute a large proportion of mine wastes. Some of the copper tailings can be recycled to recover valuable minerals. In this paper, a copper tailing was studied through the chemical analysis method, Xray diffraction and scanning electron microscope-energy dispersive spectrum. It turned out that chalcopyrite(Cu) and pyrite(S) were the main recoverable minerals in the tailing. In order to separate chalcopyrite from pyrite in low pulp pH, ammonium humate(AH) was singled out as the effective regulator. The depression mechanism of AH on the flotation of pyrite was proved by FTIR spectrum and XPS spectrum, demonstrating that there was a chemical adsorption between AH and pyrite. By Response Surface Methodology(RSM), the interaction between AH, pulp pH and iso-butyl ethionine(Z200) was discussed. It was illustrated that the optimal dosage of AH was 1678 g·t^(-1) involving both the recovery of Cu and S. The point prediction by RSM and the closed-circuit flotation displayed that the qualified Cu concentrate and S concentrate could be obtained from the copper tailing.The study indicated that AH was a promising pyrite depressor in the low pulp pH from copper tailings. 展开更多
关键词 Copper tailings Ammonium humate DEPRESSION Response Surface Methodology
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Special Conditional Similarity Reduction Solutions for Two Nonlinear Partial Differential Equations 被引量:1
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作者 MA Zheng-Yi 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第2X期199-204,共6页
We present a method of special conditional similarity reduction solutions for nonlinear partial differential equations, As concrete examples of its application, we apply this method to the (2+1)-dimensional modifie... We present a method of special conditional similarity reduction solutions for nonlinear partial differential equations, As concrete examples of its application, we apply this method to the (2+1)-dimensional modified Broer- Kaup equations and the variable coefficient KdV-mKdV equation, which have extensive physics backgrounds, and obtain abundant exact solutions derived from some reduction equations. 展开更多
关键词 conditional similarity reduction (2+1)-dimensional modified Broer-Kaup equations
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Determination of the intrinsic kinetics of iron oxide reduced by carbon monoxide in an isothermal differential micro-packed bed 被引量:1
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作者 侯宝林 张海英 +1 位作者 李洪钟 朱庆山 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2015年第6期974-980,共7页
The intrinsic kinetics of iron oxide reduced by carbon monoxide is evaluated by a method of online measuring concentration of off-gas in an isothermal differential micro-packed bed. Under the condition of getting away... The intrinsic kinetics of iron oxide reduced by carbon monoxide is evaluated by a method of online measuring concentration of off-gas in an isothermal differential micro-packed bed. Under the condition of getting away from the influence of gas diffusion and gas–solid heat transfer and mass transfer, the reaction of Fe2O3 to Fe3O4, Fe3O4 to Fe O and Fe O to Fe in the process of single reaction can be clearly distinguished from each other, and the relevant activation energy is characterized to be 75.4, 74.4, and 84.0 k J·mol-1, respectively. Therefore, the change of surface area in the reaction process due to losing oxygen could be easily calculated by combining it with pre-exponential parameters of Arrhenius equations. In conclusion, these kinetic parameters are verified by the experimental data for the process of ore reduced by carbon monoxide in a packed bed. 展开更多
关键词 Activation energy Carbon Carbon monoxide Heat transfer Isotherms KINETICS Mass transfer Packed beds Surface reactions
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Decomposition method for solving parabolic equations in finite domains 被引量:2
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作者 INC Mustafa 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2005年第10期1058-1064,共7页
This paper presents a comparison among Adomian decomposition method (ADM), Wavelet-Galerkin method (WGM), the fully explicit (1,7) finite difference technique (FTCS), the fully implicit (7,1) finite difference method ... This paper presents a comparison among Adomian decomposition method (ADM), Wavelet-Galerkin method (WGM), the fully explicit (1,7) finite difference technique (FTCS), the fully implicit (7,1) finite difference method (BTCS), (7,7) Crank-Nicholson type finite difference formula (C-N), the fully explicit method (1,13) and 9-point finite difference method, for solving parabolic differential equations with arbitrary boundary conditions and based on weak form functionals in finite domains. The problem is solved rapidly, easily and elegantly by ADM. The numerical results on a 2D transient heat conducting problem and 3D diffusion problem are used to validate the proposed ADM as an effective numerical method for solving finite domain parabolic equations. The numerical results showed that our present method is less time consuming and is easier to use than other methods. In addition, we prove the convergence of this method when it is applied to the nonlinear parabolic equation. 展开更多
关键词 Adomian decomposition method (ADM) Adomian polynomials Parabolic differential equations
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