查询词典 direct numerical method

To make use of finite element method, the field of electromagnetic wave propagating in trapezium tunnel was studied. The attenuation rate and its numerical analysis were deduced on the foundation of tiny-intervene method and the calculating program was also compiled.

应用有限元方法研究了梯形隧道中的波导场问题，并以微扰法为基础推导了波模衰减率的计算公式，编制了计算程序。

In order to calculate the integral of the Planck's blackbody formula within a limited region, trapezoid method and Simpson's method two kinds of numerical integral methods were used, and the analysis and comparison were carried on.

对普朗克黑体公式有界域内的积分，利用梯形法和辛普森法两种数值积分方法进行了分析和比较。

In this paper, the maximum likelihood algorithm with process and measurement noise for nonlinear continuous-discrete system given by Jategaonkar and Plaetschke is improved in two aspects: 1 to avoid the disadvantages of sensitivities computation by common finite-difference method, in which the perturbation sizes should be selected optionally, an improved finite-difference method with best perturbations, is presented. 2 to improve the numerical stability of Jategaonkar's algorithm, maximum likelihood algorithm with fast triangular square-root decomposition filter is given.

摘要对Jategaonkar等人给出的同时计及过程及观测噪声的非线性连续-离散系统的极大似然算法从两个方面进行了改进：1给出了计算灵敏度的最佳摄动有限差分算法，避免了普通有限差分法计算灵敏度矩阵时需人为选择参数摄动量大小而带来的缺点；2给出了具有快速三角化平方根滤波的极大似然算法，提高了原算法的数值稳定性。

A numerical method is presented to analyze the discharge process of REB accelerator with Blumlein forming line. This method can deal with the conducting delay of the gas switch and the impedance variation of the vacuum diode during the discharge process. We calculated the voltage waveform on the diode.

提出的分析强流电子束加速器放电过程的方法可对具有导通时延的气体开关、Blumlein脉冲形成线、阻抗非恒定的真空二极管负载组成的放电系统进行数值计算，所得负载上电压波形能较好地与实验符合

The numerical method of the variational principle combined with finite element method is presented in the paper.

文中介绍了运用该变分原理并结合有限元方法进行数值计算的方法。

The discrete equation was deduced by control volume integral method, and realized by numerical method.

用控制容积积分法导出了离散方程，并用数值方法进行了求解。

The geology research of carbonate reservoirs in Ordovician of Tahe oilfield showed that many large dissolved vugs and fractures were developed. The spread of the reservoir take on a very heterogeneous state. And the typical fractured-vuggy reservoirs was formed. According to the combination of the various spaces, the formation was divided into vuggy formation, fractured-vuggy formation and fractured formation. The research showed that development of the vug is relevant to the its position on the structure, the fractures, the water surface and the weathering surface. Multi-phase charge and recharge of the oil in the reservoirs resulted in the complexity of the fluid distribution. So the"Bottle Model"was brought forward to explain the movement of the water-oil contact. The special storage space and the complex fluid distribution lead to the unstability of the production and the complexity of the water cut. In order to explain the characteristic of the fracture-vug unit was brought forward and the basic principle and method of the partition of the fracture-vug unit was formed. The classification and evaluation of the units were performed according the reserve and energy. Based on the research of geology characteristic and the fluid flow in the reservoir the comprehensive numerical simulation plan of the fractured-vuggy reservoirs were established. Through the selection of the simulation unit, fluid flow type and parameter equivalent the triple media reservoir simulation model was established. Considering the practical application the model was resolved by the DKR decomposition conjugate grads method. Based on the fine reservoir description of Dsitrict IV of the Tahe oilfield the various space type were classified and combined together. The geology model of Unit S48 was constructed. Two typical single well model was established according to the geology and the dynamic phenomena. Finally the single well model and the Unit S48 were simulated by the triple media reservoir simulator. Via the local grid refinement and coarsening in the simulation good matchs were gained. Based on the results of the simulation the reserve distribution, percent of reserve produced in various space and the natural energy were analyzed. The fluid was storaged in the fractures and vugs mostly and more than 90% the produced oil came from the systems. The energy belonged to the active one. The results of simulation accorded with the fact and showed the validity and practicability the research and the simulator.

塔河油田奥陶系碳酸盐岩油藏的地质研究表明，其储层中发育着很多大型的溶蚀洞、缝，储层的平面展布呈现出极度的非均质性，形成了典型的缝洞型碳酸盐岩油藏，根据各种孔隙介质在储层中的组合，将储层分为了溶洞型、裂缝-溶洞型和裂缝型三类；研究表明溶洞储层的发育和构造位置、裂缝的发育、潜水面和风化面的位置等因素有关；多期充注的油气成藏模式导致了流体复杂的赋存状态，由此提出了所谓的"瓶子模型"，解释生产过程中油水界面的变化；特殊的储集空间类型和流体分布特征导致油田在开发过程中表现出很大的不确定性和含水变化的复杂性，为了合理的解释油气田开发过程中的动态特征，提出了"缝洞单元"的概念，并制定了"缝洞单元"纵横向划分的基本原则和依据及划分方法，并对"缝洞单元"进行了分类和评价；基于地质特征和流体在其中流动规律的研究，提出了缝洞型碳酸盐岩油藏的数值模拟综合解决方案，通过模拟单元的选择、流动类型和参数的等效，建立了三重介质油藏三维三相数值模拟模型，采用不完全LU分解预处理共轭梯度法进行了求解；在塔河油田4区精细油藏描述的基础上，将各种类型的孔隙空间进行了归类组合，建立了S48单元的地质模型；通过对油井生产动态进行分析研究，建立了两类和油井地质、生产动态相对应的单井模型；最后应用三重介质油藏数值模拟软件对单井模型和S48单元进行了数值模拟，通过局部加密和粗化等技术模拟流体流动规律，取得了很好的拟合效果；结合数值模拟结果，分析了各种介质中的储量分布、储量产出的百分比以及地层的能量，认为塔河油田缝洞型油藏中流体绝大多数储集于缝洞系统之中，所产出流体90%以上也来自于缝洞系统，其底水能量属于较充足的类型；模拟结果和油田实际情况符合较好，说明了地质研究和油藏数值模拟研究的正确性。

In view of product quality of cross wedge rolling semifinished product of automotive power-shift box middle shaft which has heavy sectional shrinkage,numerical simulation and experimental method were adopted to analyze single wedge rolling and second wedge rolling method.

针对用楔横轧工艺生产具有大断面收缩率特点的汽车变速箱中间轴毛坯所存在的产品质量问题，利用数值模拟与实轧试验对汽车变速箱中间轴毛坯一次楔成形和二次楔成形进行了分析研究，发现采用一次楔成形方法加工汽车变速箱中间轴毛坯，轧件不易发生弯曲，中间断面收缩率最大处没有发生缩颈现象，心部质量也较二次楔成形好。

In view of product quality of cross wedge rolling semifinished product of automotive power-shift box middle shaft which has heavy sectional shrinkage, numerical simulation and experimental method were adopted to analyze single wedge rolling and second wedge rolling method. It is found out that contrast second wedge rolling, single wedge rolling will not make workpiece bend easily, and after rolling the workpiece has no neck shrinkage.

针对用楔横轧工艺生产具有大断面收缩率特点的汽车变速箱中间轴毛坯所存在的产品质量问题，利用数值模拟与实轧试验对汽车变速箱中间轴毛坯一次楔成形和二次楔成形进行了分析研究，发现采用一次楔成形方法加工汽车变速箱中间轴毛坯，轧件不易发生弯曲，中间断面收缩率最大处没有发生缩颈现象，心部质量也较二次楔成形好。

This research hope uses the information of "bond yield spread" and "the market value of equity" which is available in the market to do the calibration by "Nelder-Mead Simplex Method" numerical method, and obtain the theoretical default probabilities which calculates in the most suitable property market value and the volatility of property market value.

由於资产市值与资产市值波动度的难以评估，所以无法以正向带入变数预测公司违约机率，本研究主要希望利用市场上所能获得的资讯『公司债殖利率差』、『股东权益市值』对模型以Nelder-Mead Simplex Method的数值方法做回推求得在最适资产市值与资产市值波动组合下计算出的理论违约机率。

The dissecting of samples in group2 were difficult. The root of pulmonary artery and ascending aorta failed to be unfolded because fibrous tissue was tough, right and left fibrous trigone were too firm to be solved by hand. Cardiac muscle fibers couldn't be stripped along myofibrillar trajectory since they were prone to break because of their friability.

组2的心脏解剖困难，表现为纤维组织坚韧，游离肺动脉非常困难；徒手无法松解左、右纤维三角，肺动脉和主动脉根部的游离非常困难；心肌纤维坚硬、质脆，解剖时容易断离成碎块，无法沿纤维走行方向剥离。

We have battled against the odds in a province that has become increasingly violent.

我们对在一个争夺日益激烈省的可能性。