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The evolution of male mate choice and female ornamentation: a review of mathematical models 认领 引用 被引量：3
1
作者 Courtney L. FITZPATRICK Maria R. SERVEDIO 《Current Zoology》 SCIE CAS CSCD 2018年第3期323-333,共11页
The evolution of male preferences and of female ornaments in species with traditional sex roles （i.e., polygyny） have been highlighted as areas in need of more active research by an accumulation of recent findings. ... The evolution of male preferences and of female ornaments in species with traditional sex roles （i.e., polygyny） have been highlighted as areas in need of more active research by an accumulation of recent findings. The theoretical literature on these topics is relatively small and has centered on the evolution of male choice. Mathematical models have emphasized that, under polygyny, the evolution of male preferences faces much greater competition costs than does the evolution of female preferences. We discuss ways in which costly male choice can nonetheless evolve, via （1） direct selection that favors preferences, primarily through mating with highly fecund females, （2） mechanisms that rely on indirect selection, which weakly counters competitive costs of male preferences, and （3） genetic constraints, primarily in the form of pleiotropy of male and female preferences and traits. We also review a variety of mathematical models that have elucidated how costs to male preferences can be avoided. Finally, we turn our attention to the relatively scant theoretical literature on the effects of male mate choice on the evolution of female traits. We emphasize the finding that the presence of male preferences cannot be assumed to lead to the evolution of female ornaments during polygyny, and point out situations where models have elucidated ways in which female ornaments can nevertheless evolve. 展开更多
关键词 female ornaments male mate preferences mathematical models
Flow field simulation and establishment for mathematical models of flow area of spool valve with sloping U-shape notch machined by different methods 认领 引用 被引量：11
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作者 王兆强 顾临怡 +2 位作者 冀宏 陈家旺 李林 《Journal of Central South University》 SCIE EI CAS 2014年第1期140-150,共11页
Precise function expression of the flow area for the sloping U-shape notch orifice versus the spool stroke was derived. The computational fluid dynamics was used to analyze the flow features of the sloping U-shape not... Precise function expression of the flow area for the sloping U-shape notch orifice versus the spool stroke was derived. The computational fluid dynamics was used to analyze the flow features of the sloping U-shape notch on the spool, such as mass flow rates, flow coefficients, effiux angles and steady state flow forces under different operating conditions. At last, the reliability of the mathematical model of the flow area for the sloping U-shape notch orifice on the spool was demonstrated by the comparison between the orifice area curve derived and the corresponding experimental data provided by the test. It is presented that the bottom arc of sloping U-shape notch （ABU） should not be omitted when it is required to accurately calculate the orifice area of ABU. Although the theoretical flow area of plain bottom sloping U-shape notch （PBU） is larger than that of ABU at the same opening, the simulated mass flow and experimental flow area of ABU are both larger than these of PBU at the same opening, while the simulated flow force of PBU is larger than that of ABU at the same opening. Therefore, it should be prior to adapt the ABU when designing the spool with proportional character. 展开更多
关键词 spool valve flow field simulation flow area steady state flow force mathematical model sloping U-shape notch
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Mathematical models and expert system for grate-kiln process of iron ore oxide pellet production.Part Ⅱ:Rotary kiln process control 认领 引用 被引量：10
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作者 范晓慧 王祎 陈许玲 《Journal of Central South University》 SCIE EI CAS 2012年第6期1724-1727,共4页
Rotary kiln process for iron ore oxide pellet production is hard to detect and control.Construction of one-dimensional model of temperature field in rotary kiln was described.And the results lay a solid foundation for... Rotary kiln process for iron ore oxide pellet production is hard to detect and control.Construction of one-dimensional model of temperature field in rotary kiln was described.And the results lay a solid foundation for online control.Establishment of kiln process control expert system was presented,with maximum temperature of pellet and gas temperature at the feed end as control cores,and interval estimate as control strategy.Software was developed and put into application in a pellet plant.The results show that control guidance of this system is accurate and effective.After production application for nearly one year,the compressive strength and first grade rate of pellet are increased by 86 N and 2.54%,respectively,while FeO content is 0.05% lowered.This system can reveal detailed information of real time kiln process,and provide a powerful tool for online control of pellet production. 展开更多
关键词 mathematical model expert system one-dimensional temperature field rotary kiln iron ore oxide pellet
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Mathematical models and expert system for grate-kiln process of iron ore oxide pellet production(Part Ⅰ):Mathematical models of grate process 认领 引用 被引量：6
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作者 王祎 范晓慧 陈许玲 《Journal of Central South University》 SCIE EI CAS 2012年第4期1092-1097,共6页
Grate process is an important step in grate-kiln pellet production.However,as a relatively closed system,the process on grate is inaccessible to direct detection,therefore,it is hard to control.As a result,mathematica... Grate process is an important step in grate-kiln pellet production.However,as a relatively closed system,the process on grate is inaccessible to direct detection,therefore,it is hard to control.As a result,mathematical models of temperature distribution,moisture distribution and oxidation degree distribution in pellet bed,with good universality,computation speed and calculation accuracy,are presented based on analysis of heat transfer and physical-chemical reactions during grate process.And real-time visualization of temperature,moisture and oxidation degree distribution in pellet bed during grate process is realized.Model validation is displayed,and the similarity of 91% is proved.The results can reveal real time status on grate,and provide a solid foundation for the subsequent study of artificial intelligence control system of pellet production. 展开更多
关键词 mathematical model temperature distribution moisture distribution oxidation degree distribution iron ore oxide pellet
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Mathematical models for foam-diverted acidizing and their applications 认领 引用 被引量：3
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作者 Li Songyan Li Zhaomin Lin Riyi 《Petroleum Science》 SCIE CAS 2008年第2期145-152,共8页
Foam diversion can effectively solve the problem of uneven distribution of acid in layers of different permeabilities during matrix acidizing. Based on gas trapping theory and the mass conservation equation, mathemati... Foam diversion can effectively solve the problem of uneven distribution of acid in layers of different permeabilities during matrix acidizing. Based on gas trapping theory and the mass conservation equation, mathematical models were developed for foam-diverted acidizing, which can be achieved by a foam slug followed by acid injection or by continuous injection of foamed acid. The design method for foam-diverted acidizing was also given. The mathematical models were solved by a computer program. Computed results show that the total formation skin factor, wellhead pressure and bottomhole pressure increase with foam injection, but decrease with acid injection. Volume flow rate in a highpermeability layer decreases, while that in a low-permeability layer increases, thus diverting acid to the low-permeability layer from the high-permeability layer. Under the same formation conditions, for foamed acid treatment the operation was longer, and wellhead and bottomhole pressures are higher. Field application shows that foam slug can effectively block high permeability layers, and improve intake profile noticeably. 展开更多
关键词 Foam slug foamed acid diversion acidizing nonhomogenous mathematical model
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Thermodynamic Consistency of Plate and Shell Mathematical Models in the Context of Classical and Non-Classical Continuum Mechanics and a Thermodynamically Consistent New Thermoelastic Formulation 认领 引用 被引量：3
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作者 Karan S. Surana Sri Sai Charan Mathi 《American Journal of Computational Mathematics》 2020年第2期167-220,共54页
Inclusion of dissipation and memory mechanisms, non-classical elasticity and thermal effects in the currently used plate/shell mathematical models require that we establish if these mathematical models can be derived ... Inclusion of dissipation and memory mechanisms, non-classical elasticity and thermal effects in the currently used plate/shell mathematical models require that we establish if these mathematical models can be derived using the conservation and balance laws of continuum mechanics in conjunction with the corresponding kinematic assumptions. This is referred to as thermodynamic consistency of the mathematical models. Thermodynamic consistency ensures thermodynamic equilibrium during the evolution of the deformation. When the mathematical models are thermodynamically consistent, the second law of thermodynamics facilitates consistent derivations of constitutive theories in the presence of dissipation and memory mechanisms. This is the main motivation for the work presented in this paper. In the currently used mathematical models for plates/shells based on the assumed kinematic relations, energy functional is constructed over the volume consisting of kinetic energy, strain energy and the potential energy of the loads. The Euler’s equations derived from the first variation of the energy functional for arbitrary length when set to zero yield the mathematical model(s) for the deforming plates/shells. Alternatively, principle of virtual work can also be used to derive the same mathematical model(s). For linear elastic reversible deformation physics with small deformation and small strain, these two approaches, based on energy functional and the principle of virtual work, yield the same mathematical models. These mathematical models hold for reversible mechanical deformation. In this paper, we examine whether the currently used plate/shell mathematical models with the corresponding kinematic assumptions can be derived using the conservation and balance laws of classical or non-classical continuum mechanics. The mathematical models based on Kirchhoff hypothesis (classical plate theory, CPT) and first order shear deformation theory (FSDT) that are representative of most mathematical models for plates/shells are investigated in this paper for their thermodynamic consistency. This is followed by the details of a general and higher order thermodynamically consistent plate/shell thermoelastic mathematical model that is free of a priori consideration of kinematic assumptions and remains valid for very thin as well as thick plates/shells with comprehensive nonlinear constitutive theories based on integrity. Model problem studies are presented for small deformation behavior of linear elastic plates in the absence of thermal effects and the results are compared with CPT and FSDT mathematical models. 展开更多
关键词 Plate and Shell Mathematical Models Energy Functional Thermodynamic Consistency Classical Continuum Mechanics Non-Classical Continuum Mechanics Internal Rotations Cosserat Rotations Principle of Virtual Work
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Mathematical models for properties of mortars with admixtures and recycled fine aggregates from demolished concretes 认领 引用 被引量：2
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作者 Mi Renjie Pan Ganghua +1 位作者 Li Yang Lu Xiaojun 《Journal of Southeast University(English Edition)》 EI CAS 2018年第3期371-376,共6页
In order to expand the engineering application of recycle aggregate mortars （RAM） with aggregates from demolished concretes, the models for the properties of RAM and the replacement rate of these recycled fine aggre... In order to expand the engineering application of recycle aggregate mortars （RAM） with aggregates from demolished concretes, the models for the properties of RAM and the replacement rate of these recycled fine aggregates were proposed. First, different kinds of mathematical models for the basic properties （compressive strength, water retention rate, and consistency loss） of RAM with two kinds of admixtures, thickening powders （TP） and self-made powdery admixtures （SSCT） designed for RAM, and the replacement rates were established, while the average relative errors and relative standard errors of these models were calculated. Additionally, the models and their error analyses for the curves of drying shrinkage and curing time of RAM ＋ SSCT at different replacement rates were put forward. The results show that polynomial functions should be used to calculate the basic properties of RAM ＋ TP and RAM ＋ SSCT at different replacement rates. In addition, polynonfial functions are the most optimal models for the sharp shrinkage sections in the curves of drying shrinkage-curing time of RAM ＋ SSCT, while exponential functions should be used as the models for the slow shrinkage sections and steady shrinkage sections. 展开更多
关键词 demolished concrete recycled fine aggregates admixtures recycled aggregate mortars mathematical model
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Mechanical and mathematical models of multi-stage horizontal fracturing strings and their application 认领 引用 被引量：1
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作者 Lian Zhanghua Zhang Ying +2 位作者 Zhao Xu Ding Shidong Lin Tiejun 《Natural Gas Industry B》 2015年第2期185-191,共7页
Multi-stage SRV fracturing in horizontal wells is a new technology developed at home and abroad in recent years to effectively develop shale gas or low-permeability reservoirs,but on the other hand makes the mechanica... Multi-stage SRV fracturing in horizontal wells is a new technology developed at home and abroad in recent years to effectively develop shale gas or low-permeability reservoirs,but on the other hand makes the mechanical environment of fracturing strings more complicated at the same time.In view of this,based on the loading features of tubing strings during the multi-stage fracturing of a horizontal well,mechanical models were established for three working cases of multiple packer setting,open differential-pressure sliding sleeve,and open ball-injection sliding sleeve under a hold-down packer.Moreover,mathematical models were respectively built for the above three cases.According to the Lame formula and Von Mises stress calculation formula for the thick-walled cylinder in the theory of elastic mechanics,a mathematical model was also established to calculate the equivalent stress for tubing string safety evaluation when the fracturing string was under the combined action of inner pressure,external squeezing force and axial stress,and another mathematical model was built for the mechanical strength and safety evaluation of multi-stage fracturing strings.In addition,a practical software was developed for the mechanical safety evaluation of horizontal well multi-stage fracturing strings according to the mathematical model developed for the mechanical calculation of the multi-packer string in horizontal wells.The research results were applied and verified in a gas well of Tahe Oilfield in the Tarim Basin with excellent effects,providing a theoretical basis and a simple and reliable technical means for optimal design and safety evaluation of safe operational parameters of multistage fracturing strings in horizontal wells. 展开更多
关键词 Multi-stage fracturing Fracturing string Horizontal well Mechanical model Mathematical model Hold-down packer Sliding sleeve Tarim Basin Tahe oilfield
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PHYSICAL AND MATHEMATICAL MODELS OF POLLUTION DISPERSION IN THE YANGTZE ESTUARY 认领 引用
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作者 Yi, Jiahao Gu, Peiyu Yan, Lu 《China Ocean Engineering》 SCIE EI 1989年第1期95-106,共12页
The method of combining a physical model with a mathematical model is described to study the concentration profile of pollutant dispersion in the Yangtze Estuary. the Experiments are described regarding a jet in a tid... The method of combining a physical model with a mathematical model is described to study the concentration profile of pollutant dispersion in the Yangtze Estuary. the Experiments are described regarding a jet in a tidal physical model and two-dimensional calculations of diffusion using momentum and mass conservation equations of unsteady flow. The feature of dispersion in the tidal flow, which is different from that in the steady flow such as rivers, is explained. Dilution and dispersion mainly depend on the volume of runoff and tidal range. The results of the measurement and calculation are presented, and it can be seen that they are in good agreement. 展开更多
关键词 Hydrodynamics Water Pollution Mathematical Models
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New approach to assess sperm DNA fragmentation dynamics: Fine-tuning mathematical models 认领 引用
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作者 Isabel Ortiz Jesus Dorado +4 位作者 Jane Morrell Jaime Gosalvez Francisco Crespo Juan M.Jimenez Manuel Hidalgo 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2017年第3期592-600,共9页
Background： Sperm DNA fragmentation（sDF） has been proved to be an important parameter in order to predict in vitro the potential fertility of a semen sample. Colloid centrifugation could be a suitable technique to ... Background： Sperm DNA fragmentation（sDF） has been proved to be an important parameter in order to predict in vitro the potential fertility of a semen sample. Colloid centrifugation could be a suitable technique to select those donkey sperm more resistant to DNA fragmentation after thawing. Previous studies have shown that to elucidate the latent damage of the DNA molecule, sDF should be assessed dynamically, where the rate of fragmentation between treatments indicates how resistant the DNA is to iatrogenic damage. The rate of fragmentation is calculated using the slope of a linear regression equation. However, it has not been studied if s DF dynamics fit this model. The objectives of this study were to evaluate the effect of different after-thawing centrifugation protocols on sperm DNA fragmentation and elucidate the most accurate mathematical model（linear regression, exponential or polynomial） for DNA fragmentation over time in frozen-thawed donkey semen.Results： After submitting post-thaw semen samples to no centrifugation（UDC）, sperm washing（SW） or single layer centrifugation（SLC） protocols, sD F values after 6 h of incubation were significantly lower in SLC samples than in SW or UDC.Coefficient of determination（R-2） values were significantly higher for a second order polynomial model than for linear or exponential. The highest values for acceleration of fragmentation（aSDF） were obtained for SW, fol owed by SLC and UDC.Conclusion： SLC after thawing seems to preserve longer DNA longevity in comparison to UDC and SW. Moreover,the fine-tuning of models has shown that sDF dynamics in frozen-thawed donkey semen fit a second order polynomial model, which implies that fragmentation rate is not constant and fragmentation acceleration must be taken into account to elucidate hidden damage in the DNA molecule. 展开更多
关键词 Colloid centrifugation Dynamics Fine-tuning Mathematical models Sperm DNA fragmentation
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Mathematical Models of Tire-Lateral Road Adhesion for Use in Road Vehicle Dynamics Studies 认领 引用 被引量：2
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作者 刘昭度 《Journal of Beijing Institute of Technology》 EI CAS 1997年第1期92-99,共8页
Mathematical models of tire-lateral mad adhesion for use in mad vehicle dynamics studies are set up to express the relations of adhesion coefficients with slip ratio in lateral direction.The models of tire-lateral mad... Mathematical models of tire-lateral mad adhesion for use in mad vehicle dynamics studies are set up to express the relations of adhesion coefficients with slip ratio in lateral direction.The models of tire-lateral mad adhesion revolutionize the Pacejka's model in concept and therefore make it possible for applications in vehicle dynamics studies by the expression of lateral adhesion coefficient as a function of wheel slip ratio,instead of the wheel slip angle,taking into account in the mean time the influences of mad surface condition, vehicle velocity,vertical load,tire slip angle,and wheel camber angle. 展开更多
关键词 mathematical model tire-lateral road adhesion coefficient vehicle dynamics
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Foundation of three—dimensional mathematical models for glass furnace regenerator 认领 引用 被引量：1
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作者 沈锦林 宋晨路 《Journal of Zhejiang University Science》 2002年第5期570-573,共4页
This paper presents a practical three dimensional mathematical model of circulation and heat transfer in generator of glass melting furnaces. The model was based on the heat transfer between the smoke flow and the lat... This paper presents a practical three dimensional mathematical model of circulation and heat transfer in generator of glass melting furnaces. The model was based on the heat transfer between the smoke flow and the lattice units, and between the air flow and the lattice units. This model not only bypassed the difficulty of complicated computation of the heat transfer process in the regenerator of glass furnaces, but also avoided the irrationality of fixing the temperature distribution on the surfaces. Use of the model yielded very important data and also the method for the design of the regenerator of glass furnaces in practical production. 展开更多
关键词 Regenerator Mathematical model Gas flow Temperature field
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Mathematical models of canine right and left atria cardiomyocytes 认领 引用
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作者 Ling XIA Ying-lan GONG +3 位作者 Xiu-wei ZHU Yu ZHANG Qi SUN Heng-gui ZHANG 《Journal of Zhejiang University-SCIENCE B》 SCIE CAS 2010年第6期402-416,共15页
The aim of this study is to build two mathematical models of canine ionic currents specific to right atria and left atria.The canine left atria mathematical model was firstly modified from the Ramirez-Nattel-Courteman... The aim of this study is to build two mathematical models of canine ionic currents specific to right atria and left atria.The canine left atria mathematical model was firstly modified from the Ramirez-Nattel-Courtemanche(RNC) model using the recently available experimental data of ionic currents and was further developed based on our own experimental data.A model of right atria was then built by considering the differences between right atria and left atria.The two developed models well reproduced the experimental data on action potential morphology,the rate dependence,and action potential duration restitution.They are useful for investigating the mechanisms underlying the het-erogeneity of canine regional action potentials and would help the simulation of whole heart excitation propagation and cardiac arrhythmia in the near future. 展开更多
关键词 Atrial fibrillation Canine atria Mathematical model Action potential duration restitution
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Mathematical Models for a Social Partitioning Problem 认领 引用 被引量：1
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作者 Vardges Melkonian 《American Journal of Computational Mathematics》 2021年第1期1-22,共22页
In this paper we develop modeling techniques for a social partitioning problem. Different social interaction regulations are imposed during pandemics to prevent the spread of diseases. We suggest partitioning a set of... In this paper we develop modeling techniques for a social partitioning problem. Different social interaction regulations are imposed during pandemics to prevent the spread of diseases. We suggest partitioning a set of company employees as an effective way to curb the spread, and use integer programming techniques to model it. The goal of the model is to maximize the number of direct interactions between employees who are essential for company’s work subject to the constraint that all employees should be partitioned into components of no more than a certain size implied by the regulations. Then we further develop the basic model to take into account different restrictions and provisions. We also give heuristics for solving the problem. Our computational results include sensitivity analysis on some of the models and analysis of the heuristic performance. 展开更多
关键词 Health Care Operations Research Mathematical Models for Pandemics Graph Partitioning Integer Linear Programming Heuristic Algorithms
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Mathematical Models for Vacuum Drying Characteristics of Pomegranate Aril 认领 引用 被引量：1
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作者 K. Pongtong R. Assawarachan A. Noomhorm 《Journal of Food Science and Engineering》 2011年第1期11-19,共9页
The aim of this study was to investigate and determine the best mathematical models in describing vacuum drying characteristic of pomegranate arils in the range of 55-75 ℃. The vacuum batch dryer used in the evaluati... The aim of this study was to investigate and determine the best mathematical models in describing vacuum drying characteristic of pomegranate arils in the range of 55-75 ℃. The vacuum batch dryer used in the evaluation was successful in drying a thin layer of pomegranate arils from the initial moisture content of 464.02% （d.b.） to 6.18% （d.b.） within 6.5 to 13.5 hr of continuous drying at the above mentioned temperature range. The drying rates increased with an increase in temperature and drying time. Five of the well known semi-theoretical and empirical models were fitted to the vacuum drying of pomegranate arils. The semi-empirical Midilli model has shown an excellent fit to predict drying behavior of the pomegranate arils because this model gave the highest coefficient of determination （RE）, the least chi-square （X2）, and the lowest root mean square error （RMSE）. The total drying occurs during falling period, signifying the influence of moisture diffusion during the drying. The effective diffusivity varied from 1.25× 10^10 to 2.91 × 10^10 m^2/s over the temperature range. Temperature dependence of the diffusivity was well documented by Arrhenius models. The activation energy of moisture diffusion during drying was found to be 40.46 kJ/mol. 展开更多
关键词 Mathematical models vacuum drying pomegranate
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THE MATHEMATICAL MODELS AND GENERALIZED VARIATIONAL PRINCIPLES OF NONLINEAR ANALYSIS FOR PERFORATED THIN PLATES 认领 引用
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作者 程昌钧 杨骁 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1996年第2期109-118,共10页
On foe basis of the Kirchoff-Karman hypothses for the nonlinear bending of thin plates, the three kinds of boundary value problems of nonlinear analysis for perforated fhin plates are presented under the differenr in-... On foe basis of the Kirchoff-Karman hypothses for the nonlinear bending of thin plates, the three kinds of boundary value problems of nonlinear analysis for perforated fhin plates are presented under the differenr in-plane boundary conditions and the corresponding generalized varialional principles are established. One can see that all mathematical models presented in this paper are completely new ones and differ from the ordinary von Karman theory. These mathematical models can be applied to the nonlinear analysis and the Stability analysis of perforaled thin plates in arbitraryplane boundary conditions. 展开更多
关键词 perforated thin plate non-linear analysis mathematical model generalized variational principle
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Comparison on Mathematical Models for Description of Flow Curves of Stable Austenitic Steels 认领 引用
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作者 Xing TIAN and Rujin TIANDepartment of Materials Science & Engineering, Dalian Railway Institute, Dalian 116028, China 《Journal of Materials Science & Technology》 SCIE EI CAS 2003年第1期84-86,共3页
The flow curves were measured for the stable austenitic steels 304L and 304LN by means of tensile test at room temperature,which are described by the models σ=K1εn1 + exp(K2 + n2ε), σ=Kεn1+n2lnε and σ=σ0+Kεn ... The flow curves were measured for the stable austenitic steels 304L and 304LN by means of tensile test at room temperature,which are described by the models σ=K1εn1 + exp(K2 + n2ε), σ=Kεn1+n2lnε and σ=σ0+Kεn (where, K1, K2, n1 andn2; K, n1 and n2; σ0, K and n are constant). The comparison of the maximum deviations and the consideration of thevariation of the work hardening rate with true strain show that the flow curves for the austenitic steels 304L and 304LN canbe described by the model σ=Kεn1+n2 lnε at higher precision.The derivatives of the models σ=K1εn1 + exp(K2 + n2ε) and σ=Kεn1+n2lnε with respect to true strain, exhibit theextreme at low true strain. This inherent character indicates that both models are unsuitable to describe the part of the workhardening rate curve at low true strain. 展开更多
关键词 Flow curve Mathematical model Work hardening rate
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SCALE AND TIME EFFECTS ON MATHEMATICAL MODELS FOR TRANSPORT IN THE ENVIRONMENT 认领 引用
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作者 Su Ninghu 《Applied Mathematics(A Journal of Chinese Universities)》 2007年第3期267-276,共10页
The purpose of this paper is to analyse mathematical models used in environmental modelling.Following a brief survey of the development in modelling scale-and time-dependent dispersion processes in the environment,thi... The purpose of this paper is to analyse mathematical models used in environmental modelling.Following a brief survey of the development in modelling scale-and time-dependent dispersion processes in the environment,this paper compares three similarity solutions,one of which is a solution of the generalized Feller equation(GF)with fractal parameters,and the other two for the newly-developed generalized Fokker-Planck equation(GFP).The three solutions are derived with parameters having physical significance.Data from field experiments are used to verify the solutions.The analyses indicate that the solutions of both GF and GFP represent the physically meaningful natural processes,and simulate the realistic shapes of tracer breakthrough curves. 展开更多
关键词 mathematical model environmental modelling generalized Feller equation generalized Fokker-Planck equation.
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Comparison of Mathematical Models for Describing CropResponses to N Fertilizer 认领 引用
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作者 YANSHAOHUA GUOJUNYAO 《Pedosphere》 SCIE CAS 1999年第4期351-356,共6页
Four mathematical models were systematically evaluated in describing responses of four different cropsat 7 rates of nitrogen application. Residual sum of squares and a total point ranking method were used toassess the... Four mathematical models were systematically evaluated in describing responses of four different cropsat 7 rates of nitrogen application. Residual sum of squares and a total point ranking method were used toassess the model fitting for crop responses to nitrogen application. Sparrow’s inverse quadratic polynomialmodel performed the best. 展开更多
关键词 crop responset mathematical model N fertilizer
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Application of Polynomial Mathematical Models for the Extraction of Bioactive Compounds from Plant Sources 认领 引用
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作者 Mariana Rusu Aliona Ghendov-Mosanu Rodica Sturza 《Applied Mathematics》 2021年第11期1126-1144,共19页
This article focuses on the mathematical modelling of the extraction process of bioactive compounds from grape marc and berries (Aronia, rosehip, rowan, and hawthorn). The composition of the extraction medium (the con... This article focuses on the mathematical modelling of the extraction process of bioactive compounds from grape marc and berries (Aronia, rosehip, rowan, and hawthorn). The composition of the extraction medium (the concentration of the ethyl alcohol) served as a factor of influence. Furthermore, 8 experimental measured parameters were used as variables. The experimental results were processed using Hermite polynomials. In order to adapt the degree of the polynomial, the following conditions were imposed: high precision of the mathematical model by appealing to models on interval;obtaining a nominal model and two uncertain models (upper and lower);deduction of two predictive models, one superior and one inferior. It was found that the mathematical models based on Hermite polynomials do not provide explicit analytical expressions, although they allow the establishment of parameter values for any concentration of the extraction medium. In some cases, only high-grade polynomial models ensure the modelling error below 2%. Uncertain models (upper and lower 95%) include all experimental data. Predictive mathematical models (upper and lower) were established for a high prediction. The analytical expressions of the mathematical models on intervals are non-gaps, the coefficients having non-zero values. Dependencies between the measured parameters and the composition of the extraction solvent were analyzed, the results being presented through the calculation of a surface, with all the experimental values and their average values. Thus, it was found that polynomial mathematical models provide complete information for modelling the extraction processes of bioactive compounds of plant origin. 展开更多
关键词 Polynomial Mathematical Models Error Upper and Lower Uncertainty Model Ethyl Alcohol Concentration Parameter Plant Sources
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