查询词典 mathematical expectation

To further enhance the autoleveling technology of drawing frame, a new type of dual open-loop control system was issued based on the analysis of the quality of the current autoleveling control system of drawing frame. This paper presented a mathematical model of the new control system, analyzed its mathematical theory, and elucidated the theoretical basis of dual open-loop autoleveling control system.

为进一步提高并条机自调匀整技术，在分析纺织并条机自调匀整控制系统优劣的基础上，提出一种新的双开环控制系统，给出了新型控制系统的数学模型，详细分析了其数学原理，阐述了双开环自调匀整控制系统的理论基础。

The article shows the importance of mathematics and has probed some reform for the mathematics teaching in high profession, and also elaborated the principle of "necessity and ede- quncy" for the teaching in education, which is to join up with the professional courses;paying at- tention to the ability of students for mathematical accomplishement and enduring study; empha- sizing the adaptability of fundament, interesting, ability and major with students; and also em- phasizing to merge the mathematical mod...

本文揭示了数学的重要性，对高职高专数学教学改革做了一些探讨，阐述了高职教育中，数学教学应以"必需、够用"为原则，与专业课紧密衔接；要注重培养学生的数学素养和可持续学习的能力；要注重学生的类比推理能力的培养；强调教学要与学生的基础相应，与学生的兴趣、能力、专业相适应；强调把数学建模的思想融入到教学中，以提高学生运用数学工具解决实际问题的能力。

Introduce the elementary knowledge related to dimension chain; Propose mathematical model of dimension chain, and analyze the process to build mathematical model; Analyze the search process to generate dimension chain using deep first search method.

介绍尺寸链的相关基础知识；提出尺寸链数学模型，分析了以图论为基础的数学模型的建立；分析了以深度优先搜索法进行尺寸链自动生成的搜索过程。

In inequality in the equivalent transformation process requires a lot of mathematical ideas, discuss issues such as classification, the overall for-yuan,数形结合, transformation and so on as appropriate to the infiltration of these thinking, to improve the mathematical abilities of students have great help.

在不等式的等价转化过程中需要用到诸多的数学思想，如分类讨论问题、整体换元、数形结合、转化化归等等适当地渗透这些思想方法，对提高学生的数学能力有极大的帮助。

With the investigation of the domestic and foreign literature systematically, the bases on the domestic and foreign present research and the comprehensive utilizations of the various knowledge of fluid mechanics in porous medium, reservoir engineering, mathematical physics, perforation completion, numerical simulation and so on, this article takes numerical simulation of gas reservoir of water solubility as the research aim which has completed following research works and obtained the corresponding research results: it analyzes the nature of the Water-soluble gas and formation water as well as the influent factors of the solubility through the study of massive materials; It establishes mathematical models three-dimension, the dual medium, the gas-water phase through the way of finite difference in the migration of water-soluble gas, which describes the entire process of release, migration and production in formation, where it considered the problems of variable bubble point; According to the numerical models of gas reservoir of water solubility it provides solution procedure that based on black oil model; It discovers that there will obtain the good effects in the lowly speed of development through simulation; the reinjection of formation water may largely enhance the produce degree of water-soluble gas when we consider reinjection in simulator; It considered the influence of perforated completion on development so as to increase the simulator"s versatility, It discovers that the simulator may reflect the conditions of development when we exanimate he simulator"s reliability with the empirical datum.

本文以水溶性气藏数值模拟研究为研究目标，在系统调研国内外文献、深入分析国内外研究现状的基础上，综合利用渗流力学、油气藏工程、数学物理方法、射孔完井以及数值模拟理论等多方面的知识，完成了以下研究工作并取得相应的研究成果；①通过对大量的资料调研，分析了水溶气、地层水性质、储层地质性质以及影响气体在水中溶解度的因素。②考虑到由于高压产生的大量水力裂缝，采用有限差分方法建立水溶气运移的三维、双重介质、气-水两相全隐式数学模型，该模型描述了水溶气在地层中的释放、运移和采出的整个过程。③在原有黑油模型的基础上，根据水溶性气藏数值模型编制了该数值模型的求解程序，该程序可以求解单重、双重介质两种情况。④通过模拟不同开采速度对水溶气开发效果的影响，发现开采速度较慢的时候可以取得较好的开采效果。⑤在模拟器中考虑了注水对水溶性气藏开发的影响，地层水回注可以大幅度提高水溶气的采出程度。⑥为增加模拟器的通用性，在模拟器中考虑了射孔完井方式对开采的影响。⑦检验模拟器计算的可靠性，发现在使用实验数据对水溶性气藏进行模拟时，模拟器可以很好的反映气藏开发的状态。

The mathematical programming formulation and related solution procedure are established by the traditional BEM. Through the discretization of space and time, the elastoplastic stress simulation method and reduce-basis technique are adopted to construct the self-equilibrium stress field. The numbers of variables and constraint equations in the resulting mathematical programming formulation are reduced greatly and then the dimension obstacle of computation in 3-D limit and shakedown analysis is overcome.

采用常规边界元方法建立了三维结构极限与安定分析的数学规划格式，通过对时间和空间的离散化，并采用弹塑性模拟法构造自平衡应力场和引入减缩基技术，大大减少了所形成的数学规划格式中的未知变量和约束方程的数目，有效地克服了三维结构极限与安定分析中的维数障碍问题。

Studied present measuring methods" advantages and disadvantages, and presented the necessity and importance of researching propellant transient heat transfer.2.according to 130 and aeronautic 90 rocket projectiles" structure, analysed and acquired physical and mathematical models for propellant transient heat transfer, also designed propellant temperature field simulation units for test.3.acquired discrete transient heat balance equation and temperature calculation program, and gave contrasting curves between experimental temperature values and program calculating temperature values as well as maximum errors and average square root errors between them.4.by programs based on the first class boundary condition, worked out temperature distribution in propellant temperature field simulation units at different time, analysed temperature field distribution law and main elements affecting heat transfer, acquired propellant mass weighted average temperature and one at the half position of propellant maximum thickness as well as maximum errors and average square root errors between them.5.established transient heat transfer mathematical model and temperature calculation program for the third class boundary condition, drew contrasting curves between temperature experimental values and calculation values and gave maximum errors and average square root errors between them, got temperature distribution in the simulation unit at different time and main elements affecting heat conduction, figured out propellant mass weighted average temperature and one at the half position of propellant maximum thickness as well as maximum errors and average square root errors between them.

分析了现有测试方法的优缺点，提出了研究推进剂瞬态导热的必要性和重要性。 2。根据130和航90两种火箭弹的结构，分析得到了推进剂传热的物理模型和数学模型，设计了推进剂温度场模拟实验装置。 3。得到了离散形式的瞬态热平衡方程和温度场计算程序，给出了实验温度与程序计算温度值的对比曲线及其最大偏差与均方差。 4。利用程序求出了第一类边界条件下、不同时刻推进剂温度场模拟装置中的温度分布，分析了温度场的分布规律和影响传热的主要因素，求出了推进剂质量加权平均温度和最大肉厚1／2处的温度时间曲线并给出了两者之间的最大偏差与均方差。 5。建立了第三类边界条件下的瞬态导热数学模型和温度计算程序，求出了温度实测值与计算值的对比曲线并给出了两者之间的最大偏差与均方差，得到了不同时刻温度场模拟装置的温度分布与影响导热的主要因素，求出了推进剂质量加权平均温度和最大肉厚1／2处温度及两者之间的最大偏差与均方差，讨论并确定了能代表130和航90推进剂温度的特征点的位置。

To meet the need of developing the simulator of the whole flow sheet of the mathematical Plant, mathematical model and simulation software of the plant is developed.

本论文根据催化压缩机仿真的需要，建立了催化装置压缩机数学模型，开发出催化压缩机的仿真软件。

They are :(1) The generalization of mathematical methods;(2) The mathematical method of formulization;(3) The proof of construction;(4) The introduction of algebraic symbols.

在宋元数学中，出现一些新的思想、方法和理论，主要有：(1)数学方法的一般化；(2)程序化的数学方法；(3)构造性的证明；(4)代数符号的引入。

In Introduction to Mathematical Philosophy, the later view as Russel refer to is about mathematical philosophy and foundations of mathematics.

罗素在《数学哲学导论》中所说的后一方向既数学哲学或数学基础。

A carrier gas such as nitrogen is directed through line 20 and valve 22 to connect with line 26 and mix with the gas sample.

如氮气之类的载体通过管线20和阀22引入，与管线26相通，与气体样品混合。

But for the most part, knaves and parasites had the command of his fortune

然而支配他的家产的大多是恶棍和寄生虫。