查询词典 mathematical expectation

By putting forward a research method on the history of mathematical economics through the synthesis of the intrinsic and extrinsic historical factors , the author examines some issues in the early devel-opment of mathematical economics in the light of arithmetization of analysis.

提出研究数理经济学史的内、外史相结合的方法，并以十九世纪分析算术化为背景，用该方法探讨了数理经济学早期发展的若干问题，指出数学基础尚未完善的问题是1870年前在经济研究中应用数学方法的主要障碍，而以分析算术化为代表的数学基础重建则是此后数理经济学迅猛兴起的重要原因。

Experiments of flow conductivity closure stress of typical propping agent are done, propping agent short-term flow conductivity alteration index is defined, by this, the relation between fissure short-term flow conductivity and closure stress, it is close to exponential relation. 4. Establishing the mathematical simulator of hydraulic fractured well's production in a steady state, finding the relation curve between dimensionless flow conductivity and fracture penetration coefficient by means of calculation and analyses, it is the basis of hydraulic fracture. 5. Expatiating the importance of optimized hydraulic fracturing design in reservoir engineering, advancing the optimizing design method, fracture dimension can be calculated easily when the physical parameters are known. 6. Production rate decline standard curve of vertical fractured wells is achieved by mathematical simulation, when the flow pressure is certain , by asymptotic analyze, this decline curve is close to exponential relation.

完成了国内外典型支撑剂的导流能力闭合应力影响实验，在数据分析中定义了支撑剂短期导流能力变异系数，并由此发现裂缝短期导流能力随闭合应力变化的近似符合指数关系式； 4 建立了一种水力压裂井稳态产能的数学模拟器，计算分析找到了最优无量纲导流能力与裂缝穿透比之间的新型关系曲线，它是水力压裂优化设计的基础； 5 阐述了水力压裂油藏工程优化设计的重要性，提出了优化设计方法，在已知支撑剂物性参数条件下可简洁计算最优裂缝尺寸； 6 数学模拟给出了垂直裂缝井产量递减标准曲线，在井底定压条件下通过渐近分析表明，该递减曲线满足指数关系式。

His main contribution is the first in mathematical logic, his departure from mathematical logic, the logic of established Atomism and a new realism, he became the founder of modern philosophy of one.

他的主要贡献首先是在数理逻辑方面，他由数理逻辑出发，建立起来的逻辑原子论和新实在论，使他成为现代分析哲学的创始人之一。

Through the use of a coordinate axis and function tools, it tries to create a mathematical model and integration of the choice funnel and the counter-fact inference, and to make a functional analysis of the funnel model and find the mathematical relationship between the choice funnel and the counter-fact inference, and finally to definite the demarcation of the range of its usage and the limit of its effectiveness.

通过使用坐标轴和函数工具，对"选择的漏斗"和"反事实推理"进行数学建模与整合，对漏斗模型进行函数分析，从而推导出"选择的漏斗"与"反事实推理"之间的数学关系，界定两者的使用范围和效力限度。

The first elucidates the meaning and content of the research of mathematical culture, which can be depicted as a powerful dynamic system, the core of which is the mathematics science, and parts are composed of correlated cultural fields which are interfered by mathematical idea, spirit, method, technology and theory such as.

数学文化可以表述为以数学科学为核心，以数学的思想、精神、方法、技术、理论等所辐射的相关文化领域为有机组成部分的一个具有强大功能的动态系统。数学文化涉及的基本领域包括哲学、艺术、历史、经济、教育、思维科学、政治及各门自然科学。

Correlation of drillability anisotropy index of the roller cone bit and PDC bit, the difference between drillability of the roller cone bit in perpendicular and horizontal directions of the bedding plane with the P-wave velocity anisotropy coefficient are studied respectively by means of mathematical statistics. A mathematical model is established for predicting drillability anisotropy index by using P-wave velocity anisotropy coefficient.

用数理统计方法研究分析了牙轮钻头岩石可钻性各向异性指数、牙轮钻头垂直于和平行于地层层面方向岩石可钻性差值和PDC钻头岩石可钻性各向异性指数与纵波波速各向异性系数的相关关系，建立了用纵波波速各向异性系数评价地层可钻性各向异性的模型。

The mathematical model of gas carburization is mathematical description of all kinds of physical and chemical phenomena in the process of carburization.

气体渗碳数学模型是渗碳过程中各种物理、化学现象的数学描述。

To define that the mathematical methods and mathematical cerebration are permeated and confined with each other, and there's always no difference between them.

本文共分五章，每章主要内容如下：第一章介绍了数学方法、数学思想的含义及二者之间的关系，明确了数学方法与数学思想之间是互相渗透、互相制约的。

For this reason, I gathered, analyzed and summed the conduct of the students in solving mathematical problems in my teaching. At the same time I also studied the reflection of the mathematical cerebration in their teaching.

尤其在当今教育教学改革的大潮中，把数学思想方法的渗透作为改革重点之一，已是摆在我们面前及待解决的课题。

I tried to discover that when student's solving problems, the developing level of students adapt the dialysis of the mathematical cerebration and methods. Then I try to give some advices of my teaching on how to permeate the basic mathematical cerebration.

鉴于此，我在教学实践中，对学生解决数学问题的表现进行了收集、分析、总结；同时也对教师在授课中数学思想方法的体现进行了分析研究。

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。