查询词典 approximation methods in physics

He could travel with an approximation of ease if not enjoyment in the class that disconcerted him.

他与同他步调不一致的人外出时，即使感到不快也能做到近乎坦荡。

The kernel is adding a discontinuous function for the standard approximation to account for the crack. A feasible technique is adopted for dealing with multiple cracks and intersecting cracks.

本文研究扩展有限元方法，通过改进标准有限元的单元逼近函数，使之能够表达单元内的几何不连续，从而实现切割和断裂的模拟。

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。

Periodical interference can be represented in a good approximation with a discrete Fourier series.

这类干扰信号的频率若落在有用信号的频谱范围之内，用频域处理方法则很难将其单独消除。

The mechanism of the least squares approximation that MFNN with finite nodes carried out on a given discrete point set is made, which, for the first time, results in an important theorem.

分析了有限规模多层前向网络用于离散点集上的最小二乘逼近的机理，首次给出了一个有关的定理。

Using the adiabatic approximation, the expression of the mean dissipative force are acquired.

利用绝热近似，给出了平均辐射压力的表达式。

Utilizing the linear approximation lemma, we construct one distinguisher to distinguish the weak Key-IVs for each Grain version.

虽然弱Key-Ⅳ出现的概率很低，但可以说明这两个算法的密钥初始化过程存在安全问题，有必要进行修改。

The disyllabic pitch model is obtained with the help of cubic polynomial approximation and neural network technique.

双音节音高模型是韵律调节的基础；将Kohonen自组织神经网络技术应用到音高模型的分类，并取得了较好的分类效果；（4）基于正弦模型表示的汉语语音分析与合成：将正弦模型引入到汉语的语音分析合成中来，提出了汉语的基于正弦模型表达的分析合成算法，并对在汉语普通话语音合成中的应用，包括汉语四声的变调、时长音高的调整等进行了深入的研究；对于合成音节之间的拼接问题作了探讨，并提出了自己的观点；在国内外的文献中，还没有对于该方法用于汉语语音的分析合成的应用的报道，因此是本文的主要贡献之一。

Although finding the Minimum Connected Dominating Set in an arbitrary graph is a NP-hard problem, many approximation algorithms have been proposed to construct a serviceable CDS.

由于求解最小连通支配集是一个NP难问题，许多近似算法被提出用于构建可用的最小连通支配集。

Although finding the Minimum Connected Dominating Set in an arbitrary graph is a NP-bard problem, many approximation algorithms have been proposed to construct a serviceable CDS.

由于求解最小连通支配集是一个NP难问题，许多近似算法被提出用于构建可用的最小连通支配集。

A strange and mysterious deep sea creature.

一种奇异、神秘的深海生物。

It's a yellow rectangle .

这是黄色的长方形。