近似法

Any order approximate solution of the equation was presented, and its convergence was mathematically proved by the successive approximation method.

采用逐次逼近法，求得任意阶近似解，并证明解的收敛性。

Rolling force and moment are the basic technics parameter for Assel rolling mill design,but about it,s technics calculate is very poor currently.one form by dint of approximately calculate, the result unlikelihood .J·kazanecki and domestic scholar according as metal distortion superior limit,gave some formula have some worthiness,but very complexity.the author base on practicality rolling technics, gvie a simpleness calculate means.the result close to measure numerical value,supply some reference value.

轧制力、轧制力矩是设计Assel轧管机最为基本的参数，但是目前关于其工艺计算的理论还很不成熟，只能借助于近似工程计算方法求得，结果往往偏差较大。德国的J·kazanecki和国内的一些学者提出了利用金属塑性变形场的上界法求解上述参数，具有一定的参考价值，但其数学计算相当繁杂。作者从轧制工艺实际出发，遵循塑性力学的基本原理，给出了简便易行的计算方法，具有重要的实际意义。

Firstly, the developing principles of the cylindrical internal helical gear are proposed through analyzing the movement and geometry requirements, which provides continuous contact between the mating gear surfaces. The tooth surface of the internal helical gear in the new gearing can be imagined as being generated by the normal section of the conjugated surface of the ball-tooth, moving along the radial projection of helix line of the tooth-root circle. Also, the proposed surface can be approximate tangent to the conjugated surface of the ball-tooth along a spacial curve.

首先，通过分析保证行星轮作螺环运动时与内斜齿轮实现连续啮合传动的运动和几何条件，提出了圆柱内斜齿轮齿面的两种形成原理：即由球齿运动包络曲面的法截面沿其齿根圆螺旋线在径向的投影进行拓展所形成的内齿面，以及与球齿运动包络曲面呈近似相切接触的等螺距齿面构成的内齿面。

There are two kinds of models about the higher-order correlation networks. In the two-state model, the higher-order Hebbian algorithm is usually used. For this Hebbian algorithm can have better associative memory only to orthogonal or near orthogonal prototype patterns, another learning rule, higher-order projection algorithm, is proposed in tensor representation in this dissertation.

关于高阶关联网络有两种模型，即两状态离散时间模型和模拟状态连续时间模型，在两状态离散时间高阶关联网络中最常用的是高阶Hebb规则，这种规则对于正交或近似正交的原型模式才具有比较好的联想记忆性能，因而本文用张量表示法给出了另外一种学习规则—高阶投影规则。

Up-to-date, four models of the radiative transter processes have been developed: the two-stream Eddington approximation; the Eddington factor iteration; the ray tracing method and the Monte-Carlo method.

目前所见到的四种球对称系统中的尘埃辐射转移方法可被总结为：二流Eddington近似模型方法、Eddington因子迭代模型方法、射线跟踪法和Monte-Carlo模型方法。

Results Simulation study shows that parameters estimations are approximately unbiased in MCMC when large sample size.

结果 模拟研究表明大样本时MCMC法可得到近似无偏的参数估计。

In this paper, two dimensional shallow flow—pollutants coupled model, which applies uninstructed grid finite volume method and Riemann approximate solver, is used to gain the trend of hydrodynamics and water quality change under the condition of driving force. Mechanism of nitrogen and phosphorous circle of WASP5 is considered in the water quality part of the model according to nutrition actuality of shallow lake in the cities.Xuanwu Lake is object of research in this paper.

本文针对城市浅水湖泊富营养化加剧现状，结合WASP5模型中有关氮和磷的循环机理，并将该机理写入已有的二维浅水流体水量模型中加以耦合，应用在无结构网格下的有限体积法与黎曼近似解求解的方法，求解湖泊在外驱动作用下的湖泊水动力和水质因子氮和磷的变化。

Moreover, the variation method should be more simple than the other methods.

不过，变分法比其它的近似方法要简单的多。

The approximation of meshless methods, the selection of weight function, the variational form and the discrete equation, and the numerical implementation are described.

描述了无网格法的近似方案、权函数的选择、变分形式和离散方程以及数值求解的实现。

In order to make use of time-frequency characteristic of signal,a new method of variational estimation on signal frequency by using AR model power spectrum estimation,designing band-pass filter to gain approximatively source signals and underdetermined mixed matrix,and constructing completed observation signals by expanded subspace primer vector is proposed.

充分利用信号的时频特性，提出了AR模型功率谱估计法滑动估计信号频率，设计带通滤波器近似获取源信号和欠定混合矩阵，以及扩展子空间向量基构造完备观测信号的方法，将问题转化为完备情况下的盲分离，最后运用FastICA方法实现了信号盲分离。

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。