近似公式

The approximate formula of circumferential stress and the absolute error is accepted, which is easy for the application.

周向应力的近似公式及其绝对误差的公式简单易行，便於临床应用。

For a system with time delay, a approximate formula for calculating the residual servo variance is derived.

对于存在时间延迟的自适应光学系统，推导了计算大气湍流控制残余方差的近似公式，并给出了有探测噪声情况下确定系统最优控制带宽的公式。

The result shows that frequency calculated using the finite element modeling is closed with those calculated by formula, which has proved approximate formula has very high accuracy.

研究结果表明：采用有限元建模计算基频，其结果与公式计算结果接近，证明近似公式计算精度高。

Under the assumption that the channel state information was available only at the receiver,the capacity of MIMO systems in Rayleigh fading channel was investigated on the basis of information theory. Three special expressions for the MIMO capacity over ergodic flat fading channel were derived.An asymptotic formula for MIMO systems with equal number of transmit and receive antennas in small SNR was also given. Simulation results show that this approximation is relatively accurate.

以信息论的观点为基础，在假设信道状态信息仅收端已知的情况下，采用等功率发射方案，研究了瑞利衰落信道下MIMO系统各态历经信道容量，推导了三种特殊MIMO信道的各态历经信道容量表达式，以及在小信噪比下等收发天线MIMO系统的容量近似公式，并通过仿真进行了验证，仿真结果表明该近似公式比较精确。

By academic analyzing, it is concluded that two order discrete paraxial approximation formula of the paper, multiple transmitting formula and polynomial extrapolation formula are the different forms of continuous paraxial approximation formula, so they are with nearly equivalent precision and stability and with equivalent applicability and limitation.

据此文献[3]将傍轴近似公式归结为一类从特定的无限域模型导出的人工边界条件，并且提出了新的从一般无限域模型导出的具有普适性的、称为"多次透射公式"的局部人工边界条件。那么，是否也可以从一般无限域模型导出具有普适性的傍轴近似公式呢？

Both continuous paraxial approximation formula and two order discrete paraxial approximation formula are developed for one way wave motion transmitting apparently along normal direction based on kinematics model and local polynomial interpolation function.

引言 Clayton和Engquist在1977年和1980年提出的傍轴近似公式[1，2]是迄今为止最具代表性的局部人工边界条件之一。但是上述傍轴近似公式是从特定的波动微分方程出发推导建立的，因此其普适性受到限制。

The average and maximum relative errors of the approximation do not exceed 1.0% and 2.0% respectively, compared with theoretical results, which explains its accuracy.

对此，提出了一种简单而实用的近似式，该式与理论值的平均和最大相对误差分别不超过1.0%和2.0%，说明了该近似公式的准确性。

Using mechanical energy conservation law,the simple pendulum period is analyzed and its exact formula is given.

利用三角函数作为一种近似方法，对单摆的动力学方程进行了简化，给出了大角度条件下单摆运动的周期的近似公式。

As an approximate method,with the trigonometric function,the simple pendulum dynamical equation is simplified,and the approximate formula for the period of simple pendulum movement is presented.Comparison is made between approximate formula and exac...

对近似公式和精确公式进行了对比，最后进行了数值计算，结果表明，所得到的单摆运动周期的近似公式在大多数情况下都与精确公式符合的很好。

Based on the experimental results and analysis, new contributions given in this paper is as follows:(1) the new approximate formula developed in ref [7] for △ε of continuous and noncontinuous strain hardening materials from tensile properties under various R.

实验与计算结果及分析讨论表明：用新提出的Δε模型和近似公式，可以估算不同应力比条件下连续应变硬化和非连续应变硬化材料切口根部的Δε，但是，超载作用后，Δε应近似按弹性应力循环计算；首次给出了铝合金板材和低合金高强度钢FCI超载效应的定量表达式。

The absorption and distribution of chromium were studied in ryeusing nutrient culture technique and pot experiment.

采用不同浓度K2CrO4(0，0.4，0.8和1.2 mmol/L)的Hoagland营养液处理黑麦幼苗，测定铬在黑麦体内的亚细胞分布、铬化学形态及不同部位的积累。

By analyzing theory foundation of mathematical morphology in the digital image processing, researching morphology arithmetic of the binary Image, discussing two basic forms for the least structure element: dilation and erosion.

通过分析数学形态学在图像中的理论基础，研究二值图像的形态分析算法，探讨最小结构元素的两种基本形态：膨胀和腐蚀；分析了数学形态学复杂算法的基本原理，把数学形态学的部分并行处理理念引入到家实际应用中。