近似法

The result verifies that the discrete model with power series direct discretization method requires 100 memory length to obtain the better approximation, while one with continued fraction direct discretization method requires only 10 order. Thus the continued fraction direct discretization method is preferable to digital realization of fractional order control algorithms in engineering applications.

研究结果表明，幂级数直接离散法得到近似离散模型需要记忆长度为100方可获得较好的近似，而连分式直接离散法近似离散模型为10阶时就可以获得较好的近似，因此连分式直接离散法比较适合于分数阶控制算法的实际工程应用。

More than 30 kinds of meshfree methods are reviewed in this paper in the light of weighted residual method, and different meshfree methods can be viewed as different forms of weighted residual method and/or with different approximation functions. Various kinds of meshfree approximate schemes are presented in detail, including moving least square approximation, kernel and reproducing kernel approximation, partition of unity approximation, radial basis approximation, radial point interpolation and natural neighbor interpolation.

详尽介绍了各种无网格近似方案(包括移动最小二乘近似、核近似和重构核近似、单位分解近似、径向基函数近似、点插值近似、自然邻接点插值近似等)和无网格法中常用的各类加权余量法(伽辽金格式、配点格式、局部弱形式、加权最小二乘格式和边界积分格式等)，并讨论了数值积分方法和边界条件的处理等问题。

For lensless magnification mode, the subtraction method was presented to eliminate the system total aberration to get the 3D phase information of the phase gating by using Fresnel approximation approach and the convolution approach, respectively.

在无透镜放大数字显微全息系统中，分别利用菲涅耳近似法和卷积方法再现原始物波前，并提出相减法消除系统主要球面误差，获得相位光栅的深度信息。

In a 1997 interview, Plass told me,"all sorts of things came together" that placed him at the scientific forefront: new detailed laboratory measurements of the absorption bands of water vapor, carbon dioxide and ozone; theoretical developments involving the influence of temperature and pressure on infrared absorption; new information about the carbon cycle and industrial emissions; and access to a new high-speed electronic computer to facilitate complex calculations of radiative transfer that replaced the older, graphical approximations.

在1997年的一次采访中，普拉斯告诉我：&所有的事情都赶在一块儿&，把他推到了研究的最前沿：测量水蒸气、二氧化碳和臭氧的吸收光谱带有了新的实验方法；温度和压强对红外吸收的影响理论有了新的发展；碳循环和工业废气排放有了新的资料；新的高速电子计算机代替了老式的图解近似法，让辐射传热的复杂计算变得简单了。

The Fourier approximation method is applied to solving wave height and wavelength problems of waves shoaling、for providing a normalization concept. We normalize the waves scope of depth and deep water to breaking depth into the range of 2~1. Finally、we check the experience formula computations.

中文摘要本文利用富立叶近似法解析波浪浅化过程中波高及波长的变化，并提出正规化水深之概念，将波浪存在之水深范围，深水至碎波水深正规化为2~1后，进行经验公式的推求。

Consecutive first-order reaction ; the ratio of the rate coefficient ; steady-state approximation ; computer simulation

一级连续反应；速率系数比值；稳态近似法；计算机模拟

During the process of consecutive first-order reaction, the trend of the intermediate is largely determined by the ratio of the rate coefficient; therefore this case leads to an important method:steady-state approximation.

在连续反应中，速率系数的比值很大程度上决定了中间产物浓度的走向，并由此引出了一个重要的方法：稳态近似法。

In the part of isoline filling, Firstly isoline character is deeply researched in this paper ,then two methods which one is based on border points-tracing algorithm for region filling of isograms, the other is based on equivalence region with same attribute tracing for

两种算法都较好地解决了基于栅格的填充算法所出现的问题，并改进了某些矢量算法的不足。在等值线的标注部分，文章采用多边形近似法来确定标注的位置，很好地实现了标注放在曲线的旁侧和标注放在曲线上这两种不同的标注方式。

In this s cheme, when model integration proceeds to the period of analogue updating, multiple reference states are reselected and optimal forecast vectors are est i mated from multiforecasts produced by the analoguedynamical model using the hy perplane approximation method. Such a "selectionestimation" procedure is peri od ically repeated until the entire forecast is completed.

这一方法通过引入相似更新周期的新概念，在预报进行到相似更新周期时重新选取多个参考态，并采用超平面近似法将相似动力模式产生的多个预报估计成最佳预报向量，这样的&选取-估计&过程循环往复，从而完成整个时段的预报。

The interaction of electromagnetic wave with fractal surface is computed. Statistic Kirchhoff solution is found analytically and experimentally.

研究了粗糙表面的电磁散射特性，用基尔霍夫近似法计算了散射系数，得到了散射能量的角分布。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。