数学公式

This makes more and more people pay more attention to studies and applications of numerical simulation in thermal recovery. In this research, we have developed a reliable mathematical model for thermal recovery, which takes a full consideration of the effect of viscos, gravitical and capillary forces on the three-phase flow of gas, water and oil, the effect of the temperature on the medium characteristics of liquid and solid, the phase equilibrium of gas-liquid in each component, heat transportation including connection, conduction and radiation as well as heat losses in both the overburn and underlying strata. In the space discreation of the mathematical model, we have proposed a new method based on the improvement of the conventional nine-points difference approximation, which has a higher difference accurancy.

本项研究以热力采油的主要机理为基础，充分考虑在粘性力、重力和毛管力作用下油水气三相流动，考虑温度对各种流体和固体介质物性的影响，考虑每一组分中汽液两相的相平衡，考虑热在地层中的传导、对流和辐射以及上下盖层的热损失，利用热力学第一定律、质量守恒定律和流体迁移定律，建立了正确可靠的注蒸汽数学模型；在对数学模型进行空间离散时，利用控制有限体积积分法，对以往的九点差分近似作了合理的改进，使其具有较高的差分近似精度：结果表明，该公式的近似精度要比以往文献中所给的九点差分近似精度高，可以认为，在油藏数值模拟中，如果遇到非均质情况，使用这种九点差分近似更合理。

The basic spirit of Pythagoreanism is the pursuit of the mathematical harmoniousness of the universe, and it can guide scientists to characterize the internal mystery of the physical world in terms of mathematical language and mathematical formula successfully and it fit to the current computationalism.

毕达哥拉斯主义的基本精神，正是追求宇宙的数学和谐性的思想，它能成功地引导科学家使用数学语言、公式来刻画物理世界的内在奥秘，这是与当今流行的"计算主义"相互呼应的。

This paper proves strictly the soundness of a formula of the logarithm function of a complex variable and points out the wrong conclusion concerning it in《Engineering Mathematics-Functions of a Complex Variable》compiled by the Mathematics Teaching and Research Section of Xi an Jiaotong University.

本文严格证明了关于复变量对数函数的一个公式的正确性，同时指出了西安交通大学数学教研室编写的《工程数学———复变函数》一书中有关结论的错误。

We present a strict derivation by applying Green′s theorem for a linear integral expression of the gravity anomaly produced by a 2D homogeneous source. The result thus acquired coincides with a documented formula, but our method is simpler and mathematically compact.

本文基于格林公式，给出了均匀二度体重力异常线积分表达式的严格数学推导过程，其结果与前人推导出的结果完全相同，但我们的方法在数学上更简单，也更严谨。

Leastsquare method and Lagrange's interpolation formula see their applicationsfor fitting fore-and-aft lines-whose aim is to calculate the intersection point ofequivalent inclined waterline-and differences. In order to replace theinconvenient alternate conduct of drawing and calculating, improvement hasbeen introduced into the paper which means all work can be done bycomputer. Capacity calculation cannot be done without boundary layer build-up. Fit every area curve and area moment curve is necessary because ofinterpolation.

在第二章中，给出了B样条函数的数学表达形式，推导了B样条曲线下所围面积、面积矩公式；讨论了最小二乘法和拉格朗日插值法的数学形式，并在拟合船体型线上给出首、尾轮廓线的具体实例，对比不同方法进行拟合的差异，其目的是为了求得与等体积倾斜水线的交点；而水线的确定改变了以往人工作图与计算交替进行的不足，尝试用计算机完全代替人工作图，以求有所改进；在舱容计算中，在至少包括舱室前、后壁的范围内拟合横剖面积、面积矩曲线，插值求得任一纵向位置处的剖面，以解决舱室边界条件。

In this paper, the propagation and focus properties for several modes describing hollow beam are analyzed, and the focus properties for hollow gaussian mode are particularly discussed. Furthermore, a new mode, high-order Bessel-Gauss mode, is put forward to describe hollow beams. The results for high order Bessel-Gauss beams propagating through lens focusing system and free space are derived by terms of Collins integral formula.

本文分析了几种描述空心光束数学模型的传输特性和聚焦特性，着重讨论了描述非中空光束的数学模型的聚焦特性；同时提出了一种描述完全中空的空心光束的新模型――高阶贝赛耳高斯模型，并且运用Collins积分公式，分析了这种新模型的空心光束的传输特性和聚焦特性。

Mathematical symbol is nonsensical, for only entities can be added; But numbers can also be added.

从形式上看，数学本身是由一些无意义的公式组成，只有把实体的东西加进去，数学才有意义。

Throughout his life Euler was much absorbed by problems dealing with the theory of numbers , which treats of the properties and relationships of integers, or whole numbers 0,±1,±2, etc.

没有一个人能像他那样多产和那样高超地掌握数学的技巧，在数学的许多分支中都有以他命名的公式、常数等等。

This paper introduced the appliance of probability and statistics in reality,including classical model,formula of total probability, normal distribute,mathematics expectation and the central limit theorem.While it also discusses the widely uses of probability and statistics and the close relationship with the real life.Therefore,it lays the theoretical foundation for the practical uses with probability and statistics,and the basis of mathematics model.

本文介绍了概率统计的某些知识在实际问题中的应用，主要围绕古典概型，全概率公式，正态分布，数学期望，极限定理等有关知识，探讨概率统计知识在实际生活中的广泛应用，进一步揭示概率统计与实际生活的密切联系，为应用概率知识解决实际问题，数学模型的建立，学科知识的迁移奠定一定的理论基础。

Content abstract: Mathematics is hermeticness, the logic requests oneof higher disciplines, in mathematics some concepts, the formula,principle itself quite are arid, if in the teaching still weremonotonously rigid theorizing, mechanically teaches, surely causes theknowledge to change tastelessly, student's study interest graduallydrops.

内容摘要：数学是一门严密性、逻辑性要求较高的学科之一，数学中的一些概念、公式、法则本身比较枯燥，如果在教学中仍是单调地说教，机械地传授，必定使知识变得乏味，学生的学习兴趣逐渐减退。

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。