查询词典 circular

A new frequency estimation algorithm for Time Domain Synchronization OEDM system is proposed, which utilizes the time domain circular characteristic of PN sequences to adjust frequency offset and then uses a variable step frequency scan scheme to estimate large frequency offset.

提出一种新的适用于TDS-OFDM系统的频偏估计算法，利用PN序列的时域循环特性进行预频偏调整，然后用变步长扫频进行大频偏的估计，定时同步之后再利用PN的时域循环特性进行细偏估计。

The phase of optical wave can be recovered by the intensity transport equation under the paraxial approximation For the optical system with diffraction limit, it is difficult to get the boundary radical slope of phase and sample in the circular domain boundary when using the intensity transport equation to recover the phase, consequently, we reviewed an algorithm mentioned in the reference ［4］, namely, the equation, computation domain and boundary condition are changed, then the phase is reconstructed by the multigrid method and corrected at last Moreover, the experiment system is set to testify the algorithm, and the recovered phase from the intensity data detected by CCD is compared with the result from phase retrieval algorithm, it is found that the phase reconstruction error can reach 017 λ in the case of non-uniform intensity distribution, as a result, the method is suitable for the phase recovery with low wavefront sensing accuracy.

在傍轴近似条件下，可以利用光强传播方程对畸变波前进行相位恢复。对于衍射受限的光学系统，很难获得相位的边界径向斜率值作为边界条件，此外，要获得精确的圆域边界采样值也并非易事。为了克服上述困难，进一步研究了相位恢复改进方法，即改变了方程的表示形式、计算区域和边界条件，并用多重网格法进行求解获得重构相位，最后再将其修正。为了验证算法的精确性，搭建了实验系统对算法进行实验验证，将由CCD探测的光强分布进行计算得到的相位分布与相位恢复算法的结果进行比较，证明在光强分布非均匀的情况下，该方法恢复的相位均方根误差能够达到017 λ，可以适用于波前传感精度要求不是很高的相位恢复。标签自适应光学相位恢复相位修正光强传播方程 adaptive optics phase retrieval phase correction intensity transport equation

Special solutions for the ring circular domain with crack surfaces acted on uniform compressive force, linear compressive force and linear shearing force are deduced in polar coordinate employed the eigenfunction expansion technique in the Hamiltonian system of elastic mechanics. Combined with the general solution for the above problems, the analytical solutions for crack tip fields with surfaces acted on the above three kinds of loads are obtained. These solutions offer theoretical basis to construct analytical elements for plastic analysis of crack.

从弹性力学哈密顿体系理论出发，利用平面弹性力学极坐标系下的本征向量展开求解，推导了环形圆形域裂纹边作用有均布压力、线性压力和均布剪切力情况下的特解，从而得到了裂纹表面作用有以上三种荷载情况下的裂纹尖端场的解析解，为进一步构造进行弹塑性裂纹分析的奇异解析元奠定了理论基础。

The concept of a single circular frequency breaks down in certain instances.

在某些情况下，单一的圆周频率的概念就行不通了。

Finally, by means of analysing and analogizing the tendency of dynamic impedence of soil against the circular frequency, a simplified model of soilstructure system is proposed.

最后，本文通过对大量地基动力刚度和阻尼的计算结果的分析，引入了等效刚度质量和等效阻尼质量的概念，从而简化了土—结构体系的运动方程，建立了一个简化的等效模型。在此模型的基础上，使得原本在领域内很难求解的方程可以在时域内进行求解。

Two-dimensional finite difference time domain simulation results show that, in a wide angle range (about 20 degrees), in a normalized circular frequency range of , the transmission intensity can reach over 98% for both TE and TM polarization.

二维有限时域差分模拟结果显示，在较宽的角度范围内（约20度），约化圆频率处在范围内，分束器对TE和TM偏振光的透射强度都能达到95%以上。

The paper introduces a kind of acoustics principle,and a new method which measuring resonance frequency of the circular saw blades by means of a sound level meter,inorder to provide the reference of testing resonance frequency parameter for all kinds of woodworking cutting tools.

介绍了一种利用声学原理，采用声级计为传感器的木工圆锯片固有频率测量的新方法，以期为各类木工刀具的固有频率参数测试提供借鉴。

A new method for solving the grounding resistance of two or three dimensions grounding facilities in the case of high frequency is found and the grounding resistance at high frequency of circular -shaped and rectangular-shaped grounding plates are computed.

给出了一种在高频条件下求解二维及三维接地体接地电阻的新方法，并利用这种方法具体求解了圆板及矩形板接地体的高频接地电阻。

The paper introduces a kind of acoustics principle,and a new method which measuring resonance frequency of the circular saw blade s by means of a sound level meter,inorder to provide the reference of testing resonance frequency parameter for all kinds of woodworking cutting tools.

介绍了一种利用声学原理，采用声级计为传感器的木工圆锯片固有频率测量的新方法，以期为各类木工刀具的固有频率参数测试提供借鉴。

The structural parameters of this photonic crystal terahertz waveguide with circular structure and the frequency guided in the waveguide have been obtained.

分析结果表明，增大空气填充率，可得到多条带隙和较大的带隙宽度，更易于实现纤芯导光。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。