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商品材积变型估测系统的研究 被引量:24
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作者 严若海 吴富桢 《南京林业大学学报(自然科学版)》 CAS CSCD 1992年第3期31-37,共7页
为了统一立木和伐倒木的求积方法,克服立木材积表与材种出材量表互不衔接的问题,本项研究选用浙江省实生杉木为试验材料,研究了描述立木干形的数学方法;提出变型形数的概念;导出了新的变型削度模型。通过削度模型的比较,采用最优变型削... 为了统一立木和伐倒木的求积方法,克服立木材积表与材种出材量表互不衔接的问题,本项研究选用浙江省实生杉木为试验材料,研究了描述立木干形的数学方法;提出变型形数的概念;导出了新的变型削度模型。通过削度模型的比较,采用最优变型削度模型编制了二元变形商品材积表。若将单木的胸径和树高的实测值直接输入微机,可以同时获得精确的全材积和各商品材的材积值。这可为科学经营森林、合理开发利用、落实限额采伐措施等提供森林资源的数量和质量指标的依据。 展开更多
关键词 变型形数 削度方程 商品材积
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Case study on the mechanics of NPR anchor cable compensation for large deformation tunnel in soft rock in the Transverse Mountain area,China
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作者 LI Yong ZHENG Jing +3 位作者 HUO Shu-sen WANG Feng-nian HE Man-chao TAO Zhi-gang 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第6期2054-2069,共16页
A study was conducted to analyze the deformation mechanism of strongly weathered quartz schist in the Daliangshan Tunnel,located in the western Transverse Mountain area.A large deformation problem was experienced duri... A study was conducted to analyze the deformation mechanism of strongly weathered quartz schist in the Daliangshan Tunnel,located in the western Transverse Mountain area.A large deformation problem was experienced during the tunnel construction.To mitigate this problem,a support system was designed incorporating negative Poisson ratio(NPR)anchor cables with negative Poisson ratio effect.Physical model experiments,field experiments,and numerical simulation experiments were conducted to investigate the compensation mechanical behavior of NPR anchor cables.The large deformations of soft rocks in the Daliangshan Tunnel are caused by a high ground stress,a high degree of joint fracture development,and a high degree of surrounding rock fragmentation.A compensation mechanics support system combining long and short NPR anchor cables was suggested to provide sufficient counter-support force(approximately 350 kN)for the surrounding rock inside the tunnel.Comparing the NPR anchor cable support system with the original support system used in the Daliangshan tunnel showed that an NPR anchor cable support system,combining cables of 6.3 m and 10.3 m in length,effectively prevented convergence of surrounding rock deformation,and the integrated settlement convergence value remained below 300 mm.This study provides an effective scientific basis for resolving large deformation problems in deeply buried soft rocks in western transverse mountain areas. 展开更多
关键词 soft rock large deformation NPR anchor cable physical model numerical simulation compensation mechanics
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Modeling effects of constituents and dispersoids on tensile ductility of aluminum alloy 被引量:2
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作者 宋旼 陈康华 齐雄伟 《Journal of Central South University of Technology》 EI 2007年第4期456-459,共4页
The modeling effects of constituents and dispersoids on the tensile ductility of aluminum alloy were studied.The results show that the tensile ductility decreases with the increase of the volume fraction and size of c... The modeling effects of constituents and dispersoids on the tensile ductility of aluminum alloy were studied.The results show that the tensile ductility decreases with the increase of the volume fraction and size of constituents.Thus,purification can improve the tensile ductility by decreasing the volume fraction of constituents(normally compositions of Fe and Si)and the first-class microcracks.The model also indicates that the tensile ductility decreases with the increase in the volume fraction of dispersoids.Decreasing the volume fraction of dispersoids along the grain boundaries by proper heat-treatment and improving the cohesion strength between dispersoids and matrix can also improve the tensile ductility by decreasing the volume fraction of the second-class microcracks. 展开更多
关键词 aluminum alloy tensile ductility MODELING DEFORMATION FRACTURE
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Similar Single-Difference Model and Its Algorithm for Solving GPS Monitoring Deformation Directly at Single Epoch 被引量:4
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作者 YUXuexiang XUShaoquan +1 位作者 GAOWei LüWeicai 《Geo-Spatial Information Science》 2003年第4期51-56,共6页
A new similar single-difference mathematical model (SS-DM) and its corresponding algorithmare advanced to solve the deformationof monitoring point directly in singleepoch. The method for building theSSDM is introduced... A new similar single-difference mathematical model (SS-DM) and its corresponding algorithmare advanced to solve the deformationof monitoring point directly in singleepoch. The method for building theSSDM is introduced in detail, and themain error sources affecting the accu-racy of deformation measurement areanalyzed briefly, and the basic algo-rithm and steps of solving the deform-ation are discussed.In order to validate the correctnessand the accuracy of the similar single-difference model, the test with fivedual frequency receivers is carried outon a slideway which moved in plane inFeb. 2001. In the test,five sessions areobserved. The numerical results oftest data show that the advanced mod-el is correct. 展开更多
关键词 GPS single epoch deformation information similar single-difference method model error
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A new mathematical model for predicting flow stress of X70HD under hot deformation 被引量:2
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作者 王健 王小巩 +2 位作者 杨海涛 余超 肖宏 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第6期2052-2059,共8页
To realize numerical simulation of rolling and obtain the hot forming process parameters for X70 HD steel, the flow stress behaviors of X70 HD steel were investigated under different temperatures(820-1100 ℃ and stra... To realize numerical simulation of rolling and obtain the hot forming process parameters for X70 HD steel, the flow stress behaviors of X70 HD steel were investigated under different temperatures(820-1100 ℃ and strain rates(0.01-10 s-1) on a Gleeble-3500 thermo-simulation machine. A new flow stress model was established. The linear and exponential relationship methods were applied to the parameters with respect to temperature and deformation rates. The rise of curve ends under certain conditions was analyzed. The flow stress of X70 HD steel predicted by the proposed model agrees well with the experimental results. So, it greatly improves the precision of the metal thermoplastic processing through finite element method and practical application of engineering. 展开更多
关键词 flow stress dynamic recovery dynamic reerystallization Z parameter
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Novel modeling on numerical computing the geo-deformation information in coalmine based on the GIS-Excel 被引量:1
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作者 杨可明 Wang Libo +3 位作者 Zhang Tao Qian Xiaoli Wang Linwei Liu Shiwen 《High Technology Letters》 EI CAS 2013年第2期156-161,共6页
Numerical simulation modeling is a hotspot in the geological engineering computing field. Tak- ing a fast Langrangian analysis of continua in 3 dimensions (FLAC3D) numerical modeling on com- puting the geo-deformati... Numerical simulation modeling is a hotspot in the geological engineering computing field. Tak- ing a fast Langrangian analysis of continua in 3 dimensions (FLAC3D) numerical modeling on com- puting the geo-deformation information caused by the mining subsidence in a coalmine for example, a new GIS-Excel modeling method is proposed to build geologic strata within the simulation range combined with the coal-seam dip angle of the underground mining working-planes. First of all, the coal-seam model of the numerical computing is built by using the geographic information system (GIS) according to the stripe-through principle and the calculating formula on the size of the model blocks in the paper defined, then the FLAC3D numerical computing model of all geologic strata with- in the simulation range is also built based on the calculating formula of thickness of each stratum and the Excel fast computing advantages. The GIS-Excel method is good at the higher modeling accuracy, seldom making mistakes and consuming less time. The reliability and validity of the method is veri- fied well by its practical applications in the coalmine area. 展开更多
关键词 numerical simulation mining subsidence fast Langrangian analysis of continua in 3dimensions FLAC3D) modeling geo-deformation information geographic information system (GIS)
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Gound State Properties of Nuclei in ^(295)118 α-Decay Chain 被引量:1
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作者 DONG Jian-Min ZHANG Hong-Fei +2 位作者 ZUO Wei WANG Yan-Zhao LI Jun-Qing 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第12期1055-1061,共7页
The properties of nuclei belonging to the α-decay chain of superheavy element ^295118 have been studied in the framework of axially deformed relativistic mean field (RMF) theory with the parameter set of NL-Z2 in t... The properties of nuclei belonging to the α-decay chain of superheavy element ^295118 have been studied in the framework of axially deformed relativistic mean field (RMF) theory with the parameter set of NL-Z2 in the blocked BCS approximation. Some ground state properties such as binding energies, deformations, and α-decay energies Qα have been obtained and agree well with those from finite-range droplet model (FRDM). The single-particle spectra of nuclei in ^295118 α-decay chain show that the shell gaps present obviously nucleon number dependence. The root-mean-square (rms) radii of proton, neutron and matter distributions change slowly from ^283112 to ^295118 but dramatically from ^279110 to ^283112, which may be due to the subshell closure at Z = 110 in ^279110. The α-decay half-lives in 295118 decay chain are evaluated by employing the cluster model and the generalized liquid drop model (GLDM), and the overall agreement is found when they are compared with the known experimental data. The α-decay lifetimes obtained from the cluster model are slightly larger than those of GLDM ones. Finally, we predict the α-decay half-lives of Z=118, 116, 114, 112 isotopes using the cluster model and GLDM, which also indicate these two models can corroborate each other in studies on superheavy nuclei. The results from GLDM are always lower than those obtained from the cluster model. 展开更多
关键词 superheavy nuclei relativistic mean field HALF-LIVES cluster model generalized liquid drop model
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Parameter Variations of Identified Model for Static Deformation Analysis of Arch Dam
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作者 Jiann-Shiun Lew 《Journal of Civil Engineering and Architecture》 2016年第8期894-900,共7页
The structural health monitoring of a dam is important for maintaining the safe operation and longevity of the dam system. The structural health of a large dam can be monitored from the measured static deformation. Th... The structural health monitoring of a dam is important for maintaining the safe operation and longevity of the dam system. The structural health of a large dam can be monitored from the measured static deformation. This paper presents an investigation of the parameter variations of the identified model of the measured long-term static deformation for the structural health monitoring of Fui-Tsui Dam, which is located in a very active seismic zone of Taiwan. The measured static deformation is characterized as a function of the measured physical parameters, including the effects of hydrostatic pressure and temperature variation. The identified parameters, associated with the effects of hydrostatic pressure and temperature variation, change with environmental factors, such as flooding, earthquake and foundation change. 展开更多
关键词 Static deformation large dam MODELING parameter variation structural health monitoring.
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ELASTIC DEFORMATION ANALYSIS OF MULTILA YERED STRANDS
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作者 王世文 冯继玲 +1 位作者 杨兆建 连香姣 《Journal of Coal Science & Engineering(China)》 1999年第1期44-49,共6页
This paper describes a general model for the mechanical behavior studying of general wire rope strand. An exact solution of the deformation characteristics was given when the strands is under tensile and torsional loa... This paper describes a general model for the mechanical behavior studying of general wire rope strand. An exact solution of the deformation characteristics was given when the strands is under tensile and torsional loads. The theoretical results are useful in evaluating the extensional and torsional moduli of rigidity for the strands. Finally, a simple design criterion is establised for the nonrotating ropes. 展开更多
关键词 wire ropes STRAND mechanical behavior
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Parametric modeling on spatial effect of excavation-damaged zone of underground cavern 被引量:1
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作者 刘会波 肖明 陈俊涛 《Journal of Central South University》 SCIE EI CAS 2013年第4期1085-1093,共9页
Regarding excavation-damaged zone (EDZ) around underground opening as non-homogeneous rockmass with spatial deterioration effect on stuffiness and strength, a parametric model of EDZ using radius-displacement-depend... Regarding excavation-damaged zone (EDZ) around underground opening as non-homogeneous rockmass with spatial deterioration effect on stuffiness and strength, a parametric model of EDZ using radius-displacement-dependent deformation modulus (RDDM) was proposed. Considering the nonlinearity characteristic of deformation and locality otherness of surrounding rock, deterioration parameter field of deformation modulus of rockmass around opening was quantitatively calculated through a given function. Applicability for multi-cavern condition and parameter sensibility of the model was analyzed by numerical experiments using synthetic data. Furthermore, the model was applied to identify EDZ of underground caverns of Pubugou hydropower station by calculating deterioration parameter field. Based on the parametric analysis of spatial effect and geological investigation, it is recognized that large radial deformation of deep fractured rock at the spandrel position and insufficient supporting bolts mainly result in great deformation pressure to act on the shotcrete and cause partial crack and spalling. It is shown that deterioration parameter field along the longitudinal axis of main powerhouse is evidently non-homogeneous in space and distributes exponentially along the radius from the opening. The model provides a simple and convenient way to identify the EDZ in the working state for rapid construction feedback analysis and support optimization of underground cavem from quantitative point of view and also aids in interpreting monitoring displacements and estimating support requirements. 展开更多
关键词 underground cavern excavation-damaged zone spatial effect parametric modeling deformation modulus
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Deformation Patterns and Shortening Rates in the East Part of the Kalpin Thrust System in the Southwest Tianshan Mountains During the Late Quaternary
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作者 Ran Yongkang Yang Xiaoping Xu Xiwei Cheng Jianwu Chen Lichun 《Earthquake Research in China》 2007年第2期163-178,共16页
Deformation patterns, shortening amounts and rates in the late Quaternary across the Kalpin thrust system have received tittle attention in the past. This paper attempts to discuss them, mainly in the eastern part of ... Deformation patterns, shortening amounts and rates in the late Quaternary across the Kalpin thrust system have received tittle attention in the past. This paper attempts to discuss them, mainly in the eastern part of the thrust system by doing field investigation along the faults and folds, measuring geomorphic deformation, excavating trenches in several important sites where young alluvial fans were obviously displaced and dating young deposits of alluvial terraces. There are two types of deformation in the surface and near surface for the Kalpin thrust system in the late Quaternary. They are movement of thrust faults on lower angles and bending of young folds. Both kinds of deformation are shown by shortening and uplifting of young geomorphic surfaces. The surface ages of 3 stages are calculated by dating 20 examples using the TL method in the study area and comparing the results of our predecessors on the deposition and incision times of alluvial terraces in the Tianshan mountain which are 100ka B. P., 33 - 18ka B.P. and 6.6 - 8.2ka B.P. respectively for the large-scale deformed alluvial surfaces: T3, T2 and T1 in the Kalpin region. Then, 19 sets of shortening amounts and rates are obtained in 13 sites along 4 rows of anticlines in front of the Kalpin thrust system and Piqiang fold. The shortening amounts and rates show that there are two sections where deformation is stronger than others. The two sections consist of two arcs that are towards the south. The shortening rates near the top of arcs are 1.32mm/a in the west and 1.39mm/a in the east across the thrust system, respectively. In addition, deformation is stronger in the front rows than the rear ones for bifurcate folds. 展开更多
关键词 Kalpin thrust system Deformation pattern Shortening rates Late Quaternary
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Effective grouting area of jointed slope and stress deformation responses by numerical analysis with FLAC^(3D) 被引量:3
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作者 ZHU Zi-qiang LIU Qun-yi +1 位作者 ZENG Fan-he QING Du-gan 《Journal of Coal Science & Engineering(China)》 2009年第4期404-408,共5页
To study the grouting reinforcement mechanism in jointed rock slope, first, the theoretical deduction was done to calculate the critical length of slipping if the slope angle is larger than that of joint inclination; ... To study the grouting reinforcement mechanism in jointed rock slope, first, the theoretical deduction was done to calculate the critical length of slipping if the slope angle is larger than that of joint inclination; Second, the numerical calculation model was founded by FLAG^3D, so as to find the stress and deformation responses of rock mass in the state before and after grouting, the analysis results show that the range between the boundary of critical slipping block and the joint plane that passes the slope toe is the effective grouting area (EGA). After excavation, large deformation occurs along the joint plane. After grouting, the displacements of rock particles become uniform and continuous, and large deformations along the joint plane are controlled; the dynamic displacement can re- flect the deformation response of slope during excavation in the state before and after grouting, as well as the shear location of potential slip plane. After grouting, the dynamic displacement of each monitoring point reaches the peak value with very few time steps, which indicate that the parameters of the joint plane, such as strength and stiffness, are improved; the stress field becomes uniform. Tensile area reduces gradually; whole stability of the slope and its ability to resist tensile and shear stress are improved greatly. 展开更多
关键词 SLOPE STRESS DEFORMATION cranny FLAC^3D
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Analysis of Hydrological Simulation Models Using the Parameter Combinatorial Diagram
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作者 Mikel Goni Garatea Faustino N. Gimena Ramos Jose Javier Lopez Rodriguez 《Journal of Civil Engineering and Architecture》 2015年第1期104-113,共10页
The aim of this paper is to present graphically the behaviour of a simulation model to the varying parameters and to establish the suitability of this representation as a valid tool for the analysis of the same parame... The aim of this paper is to present graphically the behaviour of a simulation model to the varying parameters and to establish the suitability of this representation as a valid tool for the analysis of the same parameters. In this paper, we define parameter combinatorial diagram as the joint graphical representation of all box plots related to the adjustment between real and simulated data, by setting and/or changing the parameters of the simulation model. To do this, we start with a box plot representing the values of an objective adjustment function, achieving these results when varying all the parameters of the simulation model, Then we draw the box plot when setting all the parameters of the model, for example, using the median or average. Later, we get all the box plots when carrying out simulations combining fixed or variable values of the model parameters. Finally, all box plots obtained are represented neatly in a single graph. It is intended that the new parameter combinatorial diagram is used to examine and analyze simulation models useful in practice. This paper presents combinatorial diagrams of different examples of application as in the case of hydrologic models of one, two, three, and five parameters. 展开更多
关键词 Parameter calibration OPTIMIZATION combinatorial diagram hydrological simulation models.
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A new constitutive law for the nonlinear normal deformation of rock joints under normal load 被引量:5
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作者 RONG Guan HUANG Kai +2 位作者 ZHOU ChuangBing WANG XiaoJiang PENG Jun 《Science China(Technological Sciences)》 SCIE EI CAS 2012年第2期555-567,共13页
In view of the deviation of the fitting results of the classical exponential model and the hyperbolic model (the BB model) from several experiment data during intermediate stress period, a new constitutive model for... In view of the deviation of the fitting results of the classical exponential model and the hyperbolic model (the BB model) from several experiment data during intermediate stress period, a new constitutive model for the nonlinear normal deformation of rock joints under normal monotonous load is established with flexibility-deformation method. First of all, basic laws of the deformation of joints under normal monotonous load are discussed, based on which three basic conditions which the complete constitutive equation for rock joints under normal load should meet are put forward. The analysis of the modified normal con- stitutive model on stress-deformation curve shows that the general exponential model and the improved hyperbolic model are not complete in math theory. Flexibility-deformation monotone decreasing curve lying between flexibility-deformation curve of the classical exponential model and the BB model is chosen, which meets basic conditions of normal deformation mentioned before, then a new normal deformation constitutive model of rock joints containing three parameters is established. Two main forms of flexibility-deformation curve are analyzed and specific math formulas of the two forms are deduced. Then the range of the parameters in the g-δ model and the g-2 model and the correlative influence factor in geology are preliminarily discussed. Referring to different experiment data, the validating analysis of the g-δ model and the g-γ model shows that the g-2 model can be applied to both the mated joints and unmated joints. Besides, experiment data can be better fit with the g-2 model with respect to the BB model, the classical exponential model and the logarithm model. 展开更多
关键词 rock joints normal deformation constitutive model FLEXIBILITY
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An improved three-dimensional spherical DDA model for simulating rock failure 被引量:13
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作者 JIAO YuYong HUANG GangHai +2 位作者 ZHAO ZhiYe ZHENG Fei WANG Long 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2015年第9期1533-1541,共9页
In this paper, a discontinuous numerical model, namely SDDARF3D(three-dimensional spherical discontinuous deformation analysis for rock failure), is proposed for simulating the whole process of rock failure. Firstly, ... In this paper, a discontinuous numerical model, namely SDDARF3D(three-dimensional spherical discontinuous deformation analysis for rock failure), is proposed for simulating the whole process of rock failure. Firstly, within the framework of the classical discontinuous deformation analysis(DDA) method, the formulation of three-dimensional spherical DDA(3D SDDA) is deduced; secondly, a bonding and cracking algorithm is constructed and the SDDARF3 D model is proposed; thirdly, corresponding VC++ calculation code is developed and some verification examples are calculated. The simulated results can intuitively reproduce the failure phenomena of rock mass, indicating that the proposed SDDARF3 D numerical model is correct and effective. 展开更多
关键词 rock failure three-dimensional spherical discontinuous deformation analysis crack propagation bonding and cracking algorithm
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Rotational Property of^(249)Cm in Particle-Triaxial-Rotor Model 被引量:1
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作者 庄凯 李则博 刘玉鑫 《Communications in Theoretical Physics》 SCIE CAS CSCD 2012年第2期271-275,共5页
We study the particle-triaxial-rotor model rotational energy spectrum and with variable moment of inertia deformation feature of very heavy nucleus 249Cm in the band structure and high spin states and locating very ne... We study the particle-triaxial-rotor model rotational energy spectrum and with variable moment of inertia deformation feature of very heavy nucleus 249Cm in the band structure and high spin states and locating very near the we determine the configurations and quadrupole and triaxial calculated results indicate that the high spin band of 249Cm is Such a nucleus is the unique one involving both multisuperheavy region. By calculating the energy spectrum, deformation parameters β and γ of the nucleus. The built upon the v[620]1/2+ configuration with deformation 1- configuration respectively parameters β= 0.296 and γ = 7.5° and the bands based on the v[622]3/2+,v[613]7/2+, v[750]1/2- are also the ones with quite large axial deformation but small triaxial deformation. 展开更多
关键词 near superheavy nucleus energy spectrum deformation parameters particle-triaxial-rotor model
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On biological population model of fractional order 被引量:1
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作者 Syed Tauseef Mohyud-Din Ayyaz Ali Bandar Bin-Mohsin 《International Journal of Biomathematics》 2016年第5期107-119,共13页
In this paper, we extensively studied a mathematical model of biology. It helps us to understand the dynamical procedure of population changes in biological population model and provides valuable predictions. In this ... In this paper, we extensively studied a mathematical model of biology. It helps us to understand the dynamical procedure of population changes in biological population model and provides valuable predictions. In this model, we establish a variety of exact solutions. To study the exact solutions, we used a fractional complex transform to convert the particular partial differential equation of fractional order into corresponding partial differential equation and modified exp-function method is implemented to investigate the nonlinear equation. Graphical demonstrations along with the numerical data reinforce the efficacy of the used procedure. The specified idea is very effective, unfailing, well-organized and pragmatic for fractional PDEs and could be protracted to further physical happenings. 展开更多
关键词 Modified exp-function method biological population model fractional calculus Caputo's fractional derivative.
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