查询词典 characteristic boundary value problem

Aiming at the signal processing problems that exist in online fault diagnosis for train running gear, based on discussing the principle of characteristic spectrum analysis, a method of full period and uniform angle sampling is applied, which transfers the vibration signal from time domain into angular domain. The angular domain signal is transferred into corresponding characteristic spectrum using FFT. Through spectrum estimation and analysis, fault characteristic spectrum values of running gear components are acquired to distinguish their faults.

在讨论特征分析方法原理的基础上，针对机车走行部故障在线监测过程中存在的信号分析与处理问题，运用整周期等角度采样方法将时域振动信号转换为角域信号，采用FFT变换将角域信号变换为对应的特征频谱，通过谱估计、谱图分析得到机车走行部各零部件的故障特征谱值，再根据该特征谱值识别机车走行部各零部件的故障。

A theoretical model is built to investigate the simulation of the infrared characteristic of the metal structure with the PCM false target.Structure parameters of the PCM false target that suit for the simulation are investigated numerically.According to the results,further request on the improvement of the thermal conductivity of PCM is presented.An experimental platform is built and the numerical model is validated experimentally.Three key thermal characteristic components of the false tank(barbette,wheel and front armor plate) are manufactured and tested,and good results are obtained.A method for the thermal conductivity enhancing of PCM by using aluminum fins is studied,the influence of the structure parameters of PCM plates to the simulation effects are investigated numerically,and the reasonable configuration parameters of the PCM plates used to simulate the steel plates of different thickness are obtained.In the study of the application of heat convection method in IR false target,a passive infrared simulation system is designed to simulate the infrared characteristic of metal constructions.The system is made up of pipe-plate,pump,receiver,and working fluid.

在相变材料应用于红外示假的研究中，通过数值模拟，研究确定了适用于制作假目标的相变材料各物性参数的范围，分析了相变材料制作假目标的可行性，并根据所得结果，选取石蜡为研究对象，建立了相变材料模拟金属构件红外特征的理论模型，研究了适用于模拟各金属构件红外特征的相变材料假目标的相关结构参数，得出了相变材料假目标模拟各金属构件红外特征的理论结果，并对相变材料的导热系数这一物性提出了进一步的改进要求；搭建了假目标实验平台，验证了所建理论模型的准确性；以坦克假目标为研究对象，制作了炮塔、负重轮和前上装甲板三个坦克假目标的关键红外热特征部件，并进行了野外实验，取得了较好的结果；以添加铝肋片作为改进相变材料导热能力的手段，理论研究了此类导热增强型相变材料的相关结构参数对模拟效果的影响，得出了模拟不同厚度钢板红外特征的导热增强型相变材料的结构参数及模拟效果。

According to the geology and well test data of Neopaleozoic tight reservoir in Tabamiao region, we begin with the conventional log response characteristic analysis and extract the classification ratio parameters to visual identify and evaluate reservoir characteristic. That is the lithologic, electric and physical ratio parameters and gas synthetical characteristic exponent.

依据塔巴庙区块上古生界致密储层各种地质、试井成果等的资料，从常规测井响应特征分析入手，提取建立了一套直观识别评价储层特征的分类比值参数，即"四性"测井特征参数：岩性比值参数、电性比值参数、物性比值参数和含气综合特征指数。

Firstly, this paper describes the history and state of the research to the minimal polynomial and the characteristic polynomial and then gives the main methods and its computational complexities for computing the characteristic polynomial and of a constant matrix, the characteristic polynomial of a polynomial matrix and the minimal polynomial of a polynomial.

本文先叙述了对最小多项式和特征多项式的国内外的研究历史和现状，然后给出了已有的计算常数矩阵特征多项式、多项式矩阵的特征多项式和常数矩阵最小多项式的主要算法及其复杂性。

The characteristic of electrohydraulic servo valve includes two respects of the stable state characteristic and dynamic characteristic.

电液伺服阀的特性包括静态特性和动态特性两方面。

Finally these characteristic point calculation a characteristic vector, person face characteristic in the database the vector proceeds to match.

最后把这些特征点计算成一组特征向量，同数据库中的人脸特征向量进行匹配。

In the fluvial deposit environment, the quartz superficial characteristic is primarily by the inferior circle, the conchoidal breakage fracture and the submarine hit pit, revealing the transformation of current to the quartz; In lake-deposit environment, quartz sand superficial characteristic is by primarily abraded edges and parallel cleavage, the quartz maintained the primitive characteristic, indicating the quartz received few transformation of fluent, different quartz grain has their different curve character.

在河流沉积环境，石英砂的表面特征以次圆、贝壳状断口和水下撞击坑为主，显示了水流对石英砂颗粒表面的改造；在湖泊沉积环境中，石英砂的表面特征以多棱角和平行解理面为主，石英砂颗粒保持了原始的特征，表明了石英砂颗粒受到水流的改造比较少。不同沉积环境中石英砂颗粒表面结构特征都具有自己的曲线特征。

Based on modeling and simulation of the steady characteristic of five-phase hybrid stepping motor driver system with fixed-chopping frequency, constant total current driving and new pentagon winding connection pattern, the paper studies the dynamic characteristic of the system, especially single step response characteristic.

本文在建立绕组接法采用新五边形接法，驱动方式采用恒频斩波恒总流驱动时的五相混合式步进电动机系统的稳态仿真模型的基础上，分析研究了其动态特性，并重点对单步响应特性进行了研究与分析。

Based on the characteristic of multi resolution of wavelets analysis, a effective method for displaying any cross section from coarse to fine resolution is presented; Based on OpenGL, the paper improved Ray-Casting arithmetic and footprint arithmetic considering the characteristic of seismic data; After introducing the characteristic of geology data and the process of seismic interpretation, the paper presents a theory frame of 3D geological interpretation software and partly realize the frame.

本文首次利用小波变换实现了三维地震数据体的快速多分辨率显示；针对地震数据体的特点，提出了基于OpenGL的改进光线投影法的快速算法及改进的脚印算法；实现了地震数据体的切割、面状地质体的构造及面状构造与地震数据体的联合显示，动画效果的形成等三维地震数据体显示效果；分析了三维地质体的特点及常规地质解释过程的特点，提出了三维地学可视化软件的体系结构，并实现了其中主要功能，取得了良好的效果。

The main contents of this report include:(1) I nvestigation and analysis of the current status and characteristics of economic development, electric power consume and electric load in North China, Northeast China, Northwest China, East China, and Central China from 2000 to 2004;(2) Indexes and contrast analysis of major power networks load characteristic in China;(3) Analysis of Major effect factors for load characteristics, including development level and structure of economic, structure of electric power consumption, geographical and climatic environment, DSM, electrovalence, load shedding and so on;(4) Change trend analysis of major power networks load characteristic in China;(5) Target forecast of major power networks load characteristic in China in the tenth five-year plan;(6) Main conclusions and suggestions.

主要内容包括：(1) 2000 ～ 2004 年华北、东北、西北、华东、华中五大电网经营区域经济发展现状及特点、用电现状及特点、电力负荷特性现状调研分析；(2)我国主要电网负荷特性指标对比分析；(3)影响我国负荷特性的主要因素分析，包括经济发展水平及经济结构、用电结构、地理环境及气候因素、需求侧管理、电价拉闸限电等对电网负荷特性的影响分析；(4)我国主要电网负荷特性变化趋势分析；(5)"十一五"期间我国主要电网负荷特性指标预测；(6)主要结论及建议。

Aquatic or marsh-growing fern allies; known to have existed since the Cenozoic; sometimes included in Lycopodiales.

生活于水中或湿地的蕨类；从新生代生存至今；有时归于石松目之中。

The engine was uprated from a 90hp Franklin to a 125hp Lycoming.

改良过的引擎是从90hp到125hp莱康明富兰克林。