查询词典 numerical system

The symplectic schemes have the ability to preserve the global symplectic structure of the phase space for a Hamiltonian system. They have substantial benefits in numerical computation for Hamiltonian system, especially in long-term simulations.

辛算法正是保持Hamilton系统内在性质的一种新型数值方法，该算法在长时间的数值计算中，具有常见数值方法无可比拟的计算优势。

By the help of numerical analysis and graphic recognition, Duffing-van der Pol non-linear vibration system with 9 parameters has been researched, the Graphic User Interface contains initial conditions, 9 parameters, power spectrums, trochoid chart of phase portraits, Poincaré mapping, analogous dynamic graph of displacements and the analogous vibration graph of mass blocks, the various dynamic characteristics of the non-linear vibration can be attained, which makes it possible to fully implement the visualized computer experiments and study of Duffing-van der Pol non-linear vibration system.

因为混沌运动十分复杂，在研究和模拟混沌运动的过程中，不但要进行大量的数值计算，而且要将计算结果直观地展示出来以便观察混沌现象，完成这一任务非计算机不可。自从洛伦茨利用计算机发现了第一个混沌吸引子以后，30多年来正是有赖于计算机技术的发展，促使混沌的研究取得迅速的发展。另一方面，混沌运动是确定性系统中出现的一种貌似随机的现象，走向混沌有其独特的过程，只有展示出它的演化过程，才能很好地了解混沌运动。也就是说，混沌是一门关于过程、演化的科学而不是一门关于状态、存在的科学。因此，只有利用计算机才能将混沌的动态过程和演化的方式真正地体现出来。

The CAD/CAM system includes (1) a main computer,(2) DSC numerical control unit,(3) TRS—I radio digital communication system,(4) Other external devices.

这个CAD／CAM系统包括：(1)主计算机，(2)DSC数控系统，(3)TRS—I无线数字通信系统，(4)其它一些外部设备。

A high2efficiency coupling system was designed by using t heo ry of optical fiber coupling for t he high2power laser and t he beam t ransform , and in t he system numerical values of lens′apert ure and focus were optimized.

本文针对工业用大功率固体激光的特点，对光纤耦合系统的光束变换，大功率激光聚焦耦合的束宽等影响光纤耦合效率的问题进行了分析。

In theory, firstly, the numerical simulation methods, such as the boundary element method, the finite difference method and the finite element method, were utilized to calculate the distribution of electric field intensity and potential of the electron-gun system, the focusing system and the whole equipment, respectively. Then, the trajectories of the electron-beam were traced by using of the Runge-Kutta method and the Monte-Carlo method associatively. The point spread function was also calculated.

在理论分析中，先后采用边界元方法、差分方法、有限元方法等科学数值计算方法，编制程序，对X射线源的电子枪发射系统、聚焦系统以及发射系统与聚焦系统的组合系统等的电场分布进行了严格的计算，在准确求得各系统电场内各个剖分点的电场场强、偏导数等参量的基础上，采用蒙特-卡罗模拟方法和不等距龙格-库塔方法相结合，追踪由LaB_6单晶阴极表面发射出的大量电子束在电场内的运动轨迹，求出点扩展函数，并根据点扩展函数的优劣，反复调节、大量计算对比，挑选出X射线源最佳的电极结构及其组合。

Discussion on membrane formation mechanismBased on the Flory-Huggins theory, Phase equilibrium equations of PVDF/DMAc/water ternary system were wrote out, and the binodal and spinodal lines in the phase diagrams of the system were obtained via numerical calculation. Combined the kinetic description and the thermodynamic phase diagram, membrane formation process were analyzed, which prepared the theoretical foundation for the further membrane formation mechanism research.

论文主要从如下四个方面展开：(1)PVDF疏水膜成膜分相机理探讨基于Flory-Huggins理论推导了三元制膜体系凝胶分相组成的线性表达式，并通过&浊点法&测定了PVDF／N，N-二甲基乙酰胺／水／成膜体系的凝胶边界线组成，通过对实验数据的拟合，得到了简捷直观的线性表达式，ln(φ_1)/(φ_3)=bln(φ_2)/(φ_3)+a，误差小于3％。

In this paper, taking one 1900t/h supercritical pressure once—through boiler installed in East boiler company as subject investigated, analyzing the structure and characteristic of unit, from the mechanism of units, based on the law of quality conservation, energy conservation and momentum conservation, having Lagrange fluid particle tracing idea in hydrodynamics field application in analyzing of unit operational characteristic, author build up the nonlinear distributed parameter general dynamic mathematical model of single-phase heating surface or diphase heating surface in the steam-water system for supercritical pressure once—through boiler, which is suitable numerical calculation and simulation for large scale disturbance and full working conditions change, and enough materializing distributed characteristic of thermodynamic parameter in process and time lag characteristic of energy transportation in tache. The transient responses curve of the system main variables under several disturbance are computed by Computer Simulation for the model, and theoretical analysis shows that the simulation results are reasonable.

本文以东方锅炉集团公司的一台1900 t /h超临界压力直流锅炉为研究对象，在分析机组结构和特性的基础上，从机组的工作机理出发，以质量、能量、动量守恒定律为依据，将流体力学领域中的Lagrange流体质点追踪思想用于机组运行特性的分析上，建立了适用于超临界压力直流锅炉汽水系统单相、双相受热面的非线性分布参数通用动态数学模型，该模型适合于大扰动全工况变化的数值仿真计算，充分体现了过程热力参数的分布特性和环节中能量输送过程的时滞特性，并对模型通过计算机仿真得出各种扰动下系统主要变量的响应曲线，从理论上分析了仿真结果的合理性。

This paper brings forward an embedded, opening and latticing numerical control structure based on the research of the theory of Embedded System and Flexible Embedded Digital Control System and describes the structure design in hardware and software.

本文在研究嵌入式系统理论和柔性嵌入式数控系统理论的基础上，提出了基于嵌入式、开放性、网络化的数控体系结构，并给出了软硬件体系结构的设计。

The third chapter talked about two different treatments of quantum decoherence in V〓 system. For one the decoherence factor is been expressed in the form of a random external field. And the mean density matrix is calculated to signal the decoherence by showing its nondiagonal elements to approach to zero. In another numerical work done by us, random interaction between system and environment is imposed to mimic the decoherence factor.

第三章讨论了V〓体系中量子相干性研究的两个工作，一个用随机外场来代表消相干因素，采用对系统的密度矩阵进行随机平均的解析方法得到一些结果，一个是我们用数值计算方法的处理，其中消相干因素考虑成系统和环境的相互作用。

The bifurcation and chaos behavior of impact and rubbing fault rotor system caused by the parameters of nonlinear rigidity, rotor rotating speed, eccentric mass is analyzed, in the numerical value analysis method. The bifurcation diagrams, maximum Lyapunov exponent diagrams, Poincaré maps, phase plane portraits, trajectories of journal center, time-history curve, amplitude spectra diagrams of the rotor motion are used. The convert and evolution course of periodical response, quasi-periodical response, double-periodical bifurcation, chaos of the system response is analyzed.(3). It is deduced that the general differential equation of bending-torsional-pendular coupling vibration about rotor with the gyroscopic moment. On the basis of this equation, the general differential equations of coupled bending, torsional and pendular nonlinear vibration about rotor with unbalance character and rubbing character are deduced.

2建立了具有非线性刚度的转子系统在非稳态非线性油膜力作用下的径向碰摩动力学微分方程，并应用含高阶余项的非线性动力方程的线性化数值法研究了此类系统响应的复杂动力学行为，利用转子响应的分岔图、最大Lyapunov指数曲线、Poincaré截面映射、时域波形、相轨线、轴心轨迹、幅值谱等图形分析了系统响应的周期运动、拟周期运动、倍周期分岔、混沌等运动形式的转化与演变过程，重点研究了非线性刚度、转子转速、偏心质量等系统参数对碰摩故障转子系统的分岔和混沌行为的影响。

We have no common name for a mime of Sophron or Xenarchus and a Socratic Conversation; and we should still be without one even if the imitation in the two instances were in trimeters or elegiacs or some other kind of verse--though it is the way with people to tack on 'poet' to the name of a metre, and talk of elegiac-poets and epic-poets, thinking that they call them poets not by reason of the imitative nature of their work, but indiscriminately by reason of the metre they write in.

索夫农 、森那库斯和苏格拉底式的对话采用的模仿没有一个公共的名称；三音步诗、挽歌体或其他类型的诗的模仿也没有——人们把&诗人&这一名词和格律名称结合到一起，称之为挽歌体诗人或者史诗诗人，他们被称为诗人，似乎只是因为遵守格律写作，而非他们作品的模仿本质。

The relationship between communicative competence and grammar teaching should be that of the ends and the means.

交际能力和语法的关系应该是目标与途径的关系。