具有Hardy-Sobolev临界指数的p-Laplacian方程解的存在性和多重性

通过变分方法和分析技巧,得到了一类具有Hardy-Sobolev临界指数和超线性的非线性项p-Laplacian方程解的存在与多重性结果.     

Prediction of the energy value of ewe milk at early lactation

Abstract

This study was conducted in order to develop equations for the prediction of ewe's milk energy content via milk composition. Twenty-four multiparous Chios breed ewes were examined in a eight-week study that started at parturition. Animals were fed in groups (12 ewes), with two, highly concentrated (forage to concentrate ratio 30:70 DM), rations differing in undegradable protein (UP) content. The following equations are proposed: (i) when fat content (F; g/kg) is the only variable: EV_L(kJ/kg)=39×F+2090 (SE 0.30 kJ/g), (ii) when total solids (TS; g/kg) is the only variable: EV_L(kJ/kg)=33×TS–1222 (SE 0.26 kJ/g) whilst the following equation is proposed when solids non fat content (SNF; g/kg) is an additional known variable: EV_L (kJ/kg)=39×F+36×SNF–1990 (SE 0.27 kJ/g). Fat corrected milk (FCM) yield can be calculated by the following equation: Y (FCM 6%; kg/d)=L (kg/d)×[0.472+0.0088×F (g/kg)], where L is milk yield.     

Deformation Analysis of Thermo Elastic Plastic on ReinforcedConcrete Structure Subjected to Fire

To investigate the mechanical behavior of reinforced concrete structure subjected to fire, the incremental thermo elastic plastic creep constitutive equations of steel and concrete in consideration of temperature and creep deformation were obtained based on different yield rules and the elastic plastic theories. The nonlinear analysis for reinforced concrete simply supported slab was carried out with consideration the variation of the mechanical properties of steel and concrete with temperature. The effectiveness and applicability of the constitutive equations were verified with the test results from relevant literature. The nonlinear analysis was employed for one bay one storey reinforced concrete frame under fire and the variation of displacement at partial nodes was analysed. It was found that the reinforced concrete structure at a high temperature would have a significant deformation. And the displacement change curves of beam column joints of reinforced concrete frame were not monotonous trend and there were inflexion points. The vertical displacement values of beam column joints were less than those at midspan of cross beam.     

Another Method of Deducing Maxwell Equations

It is well-known that the theoretical basis of macroscopic electrodynamics is Maxwell equations,include which Coulomb law, Biot-Savant law, Faraday law of electromagnetic induction and the hypothesis of induced electric field and displacement current. When the distribution of electric charge and electric current varies with time, if given Coulomb law, Biot-Savant law, Faraday law of electromagnetic,and the hypothesis of induced electric field, through the vector analysis, Maxwell Equations are given without the hypothesis of displacement current.     

Synchronization of Chaotic Systems Employing the Theory of Application of Linear Time-varying Impulsive Differential Equations

Employing the stability theory of linear non-autonomous impulsive differential equations, some sufficient conditions for the synchronization of unified chaotic systems and Lorenz chaotic systems are derived. This method can be applied to most of chaotic systems. The numerical simulations also demonstrate the efficiency of impulsive control.     

An optimization algorithm for calculating the critical parametersof multicomponent mixture refrigerants

Aiming to calculate the true critical parameters of refrigerant mixtures, the Helmholtz free energy stability criterion for thermal systems is adopted to establish a calculation thermodynamic model of the true critical parameters. A novel optimization alg     

钵苗在鸭嘴式栽植机构中的运动微分方程及应用试验

随着机械化栽植速度的提高,为避免在栽植过程中,钵苗在栽植机构的栽植嘴内运动时间过长而无法及时落入苗沟或穴坑造成栽植失败,并对下一循环的栽植产生不利影响,该文将钵苗相对栽植嘴的运动分为与栽植嘴壁面碰撞、平面运动和沿栽植嘴壁面下滑3个阶段,分别建立了各阶段钵苗的运动微分方程。选择穴盘规格为128孔、苗龄为2~3片真叶、土钵含水率63%左右的西兰花钵苗,利用所建立的钵苗运动微分方程计算得到了变形椭圆齿轮行星轮系栽植机构作业时钵苗与栽植嘴之间的相对运动、相互作用力和钵苗从进入到离开栽植嘴的时间。利用高速摄影及其视频处理技术对钵苗在变形椭圆齿轮行星轮系栽植机构栽植嘴中的运动进行了试验研究,得到的钵苗从进入到离开栽植嘴时间与理论分析基本吻合,可见模型的建立及其计算是正确的。同时分析得到当投苗时钵苗轴线与水平面夹角为55°、质心速度为1.5 m/s、质心速度与水平面夹角为68°时,此栽植机构在速度小于147 r/min时钵苗能顺利落入穴坑,为栽植机构的最高转速设计提供了依据。     

注水驱油过程中地层流体渗透各向同性时的压力分布

通过把渗流的偏微分方程变成其弱解积分形式,针对油田的某一井排油水井的分布情况,用有限元法计算了注水驱油过程中储层渗透各向同性时的油、水井稳态压力分布和瞬态压力分布。结果表明,在注水加压驱油时,压力有一个逐渐变化的过程,最后达到新的稳定压力平衡状态,并揭示了地层流体的非稳态渗流是稳态渗流的特例。     

用加边矩阵求解非齐次线性方程组的尝试

笔者在文（１）中用加边矩阵求出了齐次线性方程组的基础解系，在此基础上，本文进一步考虑求解非齐次线方程组的问题。文末也给出了一种用加边矩阵求解逆矩阵的方法。