查询词典 difference equation

In this paper, an iterative algorithm is proposed to find the generalized centrosymmetric solution pair of matrix equation AXA~T+BYB~T=C. The solvability of the matrix equation can be determined automatically in the iterative process. When the matrix equation is consistent, the solution pair can be obtained within finite steps in the absence of round-off errors.

该论文运用迭代方法研究了矩阵方程的一般中心对称解解，特别地，当矩阵方程是相容的时，经过有限步就能求出该方程的一般中心对称解解，然后以此为主要依据进一步研究了矩阵方程的最优近似解，最后举例验证了该论文的主要结论。

Effective dielectric constants of diphase composite are simulated by Monte Carlo - finite element method on square lattice in two - dimension. Logarithmic mixing rule, Wakino's equation, Maxwell - Wagner's equation and general effective medium equation are used to fit the computed data.

采用蒙特卡洛有限元法，在二维正方形格子上模拟计算了两相复合介质的等效介电常数，并用对数混合方程、Wakino方程、Maxwell-wagner方程和通用有效介质方程对模拟数据进行了拟合。

The saturation equals 1 in saturated region.The piezometric tube waterhead equals position head by neglecting the effect of capillarity in unsaturated region.So the nonlinear parabolic equation of seepage flow will degenerate to Laplace equation about piezometric tube waterhead in saturated region and convective equation about saturation in unsaturated region respectively.

将渗流域分为饱和区与非饱和区，为避免研究复杂的多相流问题，可以认为非饱和区是与大气相通的，则测压管水头中的压力与大气压相等，使测压管水头等于位置水头，从而渗流控制方程在两个区域中分别退化为关于测压管水头的拉普拉斯方程和关于饱和度的对流方程。

A set of apparatus for determining solid-liquid equilibrium data at atmospheric pressure has been established. The solubility of sebacic acid in water, 20% ethanol aqueous solution, 50% ethanol aqueous solution, 80% ethanol aqueous solution and ethanol were determined. Wilson equation, ideal thermodynamics equation and λh equation were applied to describe solid liquid equilibria data.

建立了一套常压固液平衡测定装置，测定了癸二酸在水、20％乙醇-水溶液、50％乙醇-水溶液、80％乙醇-水溶液、无水乙醇体系中的溶解度，并用Wilson方程、热力学简化方程和λh方程模型对实验数据进行关联。

Herschell-Buckley model have another name called H-B model, equation form as follows:〓 Rheology equation of broad sense:〓 The equation is to sheat rate:〓 In the flow of the annular interspace of the pipeline:〓 thereinto n'=〓 All of the experiment of this thesis utilize the rheology test-bed, it can test the pressure losses relevant datum, and imitate the hole and carry on the test related to rock bits movement.

Wise通过对消防泡沫流经普通铁管的流动阻力的研究发现，泡沫并没有宾汉模型的屈服值，认为泡沫纯粹属于假塑性流体，其流变模式为： Logμ=logτ〓+alog〓+b Mitchell使用毛细管研究泡沫流动，Mitchell用下式计算τ〓和μ〓：〓而Buckingham-Reiners对泡沫修正了用于管内流动的宾汉塑性模型，形式如下：〓 Herschell-Buckley模型—又称H—B模型，方程形式为：〓广义流变方程：〓剪切速率方程为：〓在环空中的流动时〓其中〓完成本论文的所有工作都是在试验台上进行，在该试验台上可进行与压力损失相关的数据测试，可模拟钻孔进行与岩屑运动有关的测试研究。

In the study of the water oxygen resume, start off the mechanism of the atmosphere oxygen resume, the paper first poses the atmosphere oxygen resume equation and oxygen resume coefficent calculation formulation of the static state water. The number of the progressing of the Blak-phelps equation is made certain, and the atmosphere oxygen resume equation and coefficent are ensured in both conditions of considering the floor reflection and unconsidering the floor reflection.

在对湖库水体复氧研究中，从大气复氧的机理出发，首先提出静态水体的大气复氧方程和大气复氧系数计算公式，其中对Blak-phelps方程级数项项数的确定，不考虑底部反射的大气复氧方程和考虑底部反射的大气复氧这三个问题进行了深入分析，得出相应的结果。

Based on the theories of rheology, Non-Newtonian Fluid Mechanics, petroleum chemistry, crystallography and pipeline technology etc. and sampling Huabei crudes, experimental indexes and programmes are drew out, integrating the oil properties and parameter analysis; in terms of the macro analysis of continuum mechanics, substantial experiments are conducted with HAAKE RS600 rotational rheometer and the rheological equation as well as the viscosity-temperature equation are further developed with tested rhrogramme and viscosity-temperature curve, respectively. Beased on the researches on thixotropic mechanism and thixotropy fluid property, hysteresis loop curve, structure failure and viscosity build-up curve as well as shear stress decrement curve for one type oil are first present in this paper. According to the theoretical researches and testing results, a novel thixotropy equation with τ=τ_∞e~ pattern, which is of hi-accuracy, few parameter and simplicity, is developed. Considering the influence of various parameters on rheological behaviour, depressant adding condition is optimized and experimental evaluation on BEM-5P is conducted, which further unrip its mechanism on the Huabei crude. A corresponding viable pipe transportion programmel is also recommended.

本文基于原油流变学、非牛顿流体力学、石油化学、结晶学、原油管输工艺学等理论，以华北原油为研究对象，结合原油物性及实验影响因素分析，制定出实验研究的评价指标及实验方案；从连续介质力学宏观分析的角度，利用HAAKE RS600高端旋转流变仪开展了大量的室内实验，并运用微观研究方法，测定了油样的流变曲线和粘温曲线，建立了流变方程和粘温方程；通过对触变性机理和触变性流体特征的研究，首次对华北原油测定出滞回环曲线、结构破坏与恢复粘时曲线、剪切应力裂降过程曲线，并在理论研究和实验结果的基础之上，建立了能定量描述含蜡原油剪切应力裂降过程的新型三参数触变模式τ=τ_∞e~b/(t+c，该模型具有精度高、参数少、实验简便且适用性强的特点；通过对含蜡原油流变性的影响因素理论研究，开展了加剂条件优选及BEM-5P降凝剂室内评价实验，进一步揭示了降凝剂对华北原油作用机理，在此基础之上，提出了华北原油管输的可行性方案。

The ammonia volatilizing of fertilizer is suit to the dynamic equation as Y=a+bt, the coefficients in the equation are related to the kind of fertilizer, temperature and water content of soil, and the dynamic equation about ammonia volatilization including water and temperature and the is developed.

肥料氨累积挥发量符合零级反应动力学方程Y=a+bt，方程中系数与肥料种类、温度和土壤含水量有关，碳铵a、b值均比硫酸铵高，土壤含水量增大，a、b值降低，温度升高，a、b值增大，并由此得到含温度或土壤湿度因子的肥料氨挥发动力学方程，并建立了含水、热因子的肥料氨挥发水热耦合效应动力学方程。

In this paper, we study nonlinear perturbation analysis of mesoscale verticalcirculation and evolution equation by means of f plane, non-hydrostatic balance andfilter model. Outstanding nonlinear characteristic of mesoscale disturbance invertical direction, we obtain nonlinear symmetric disturbance equation anddisturbance amplitude s evolution equation by use of multi-scale and singularperturbation technique.

中文摘要：本文采用f平面、非静力平衡、滤声波模式，讨论了大气中尺度非线性动力学方程，通过尺度分析重点突出了扰动在垂直方向上的非线性特征，从而得到了对称扰动非线性方程，运用多重尺度方法和摄动分析讨论了对称扰动非线性重力惯性波的演化过程，得到非线性重力惯性波振幅演化服从广义的非线性Schrdinger方程。

In this dissertation, first, based on theory of cutting tooth about the gleason spiral bevel gear, the equation of meshing in the process of cutting tooth, the surface equation of generating gear as well as the general tooth surface equation of the double circular arc spiral bevel gear, using GB12759-1991 type of double circular arc gear as a basic gear profile, a three-dimension solid model of double circular arc spiral bevel gear which has the good adaptability was carried out by used of Unigraphics software;Second, by researching of the algorithm about contact and collision as well as various contact types based upon Contacting Finite Element Method, a foundation was laid for selecting the contact type in analyzing contact stress of double circular arc spiral bevel gearing;Finally, through the connection port of PARASOLID between UG software and ANSYS/LS-DYNA software, the three-dimension solid model of double circular arc spiral bevel gearing obtained above in UG was imported into ANSYS/LS-DYNA, a finite element analyzing about contact stress of double circular arc spiral bevel gearing was carried out by applying new loading method.

本文首先基于格利森弧齿锥齿轮加工原理及切齿啮合过程中的啮合方程、产形轮齿面方程以及双圆弧弧齿锥齿轮的齿面方程，选用GB12759-1991型双圆弧齿轮基本齿廓为基准齿形，利用Unigraphics软件的建模功能，绘制了有较好适应性的双圆弧弧齿锥齿轮传动三维实体模型。其次，描述了应用有限单元法进行实体接触与碰撞问题算法的公式，研究了有限元分析中的各种接触类型以及双圆弧弧齿锥齿轮接触应力分析中所选择接触类型的依据。最后，通过UG软件和ANSYS/LS-DYNA之间的PARASOLID接口工具包，将UG软件中得到的啮合齿轮模型导入ANSYS/LS-DYNA有限元分析软件，给出一种新的加载方法，进行了双圆弧弧齿锥齿轮传动的接触应力的有限元分析。

Liapunov—Schmidt method is one of the most important method in the bifurcation theory.

Liapunov—Schmidt方法是分叉理论的最重要方法之一。

Be courteous -- even when people are most discourteous to you .

要有礼貌──即使当別人对你最不礼貌的时候。