角频率

With the reduction of operation frequency, the height of thepyramidal absorber in the microwave anechoic chamber will increase correspondingly.

随着使用频率的降低，微波暗室角锥吸收体的高度也相应增加。

So there need not only no failure but working in a stably good condition in the ignition system, the using condition and adjust of the use factors are the most important thing for the system performance. The paper analyses the characteristics of electronic ignition system, points out that determinant use factors are mainly the voltage of battery, the occupy-emptiness rate of the ignition signal, the clearance of spark plug, the resistance of high-voltage part, and the cam angle of spark advance.

本论文重点分析了电子点火系统故障特征，论证了决定电子点火系统性能的使用因素主要有电瓶电压、点火信号发生器发出电压信号的占空比、火花塞间隙、高压阻抗、点火提前角，这些因素在点火系使用过程中故障率占点火故障比例最大，故障出现的频率最高，而且有时常因维修调整不当导致点火系统性能变差。

According to the results of the tests, the unsteady aerodynamic was calculated at arbitrary angles of the tailplane and pitching frequency using the method of a data base model.

根据风洞实验结果，采用基于三角剖分数据库建模的方法，计算了任意平尾偏角和任意振动频率时的背景机动态气动特性，与实验结果比较表明，提出的有平尾偏角的建模方法能提供任意舵偏时的全机气动特性。

Considering the influence of fluid's viscosity and large amplitude sloshing, the 2-dimension coupling system composed of uncompressible viscous fluid and ideal elastic structure of rectangle aqueduct is studied by using ADINA to develop the models in this paper. Analyze the dynamic response of the rectangle aqueduct structure by large amplitude liquid sloshing. Under the horizontal harmonic excitations with different amplitudes, analyze the harmonic response of the rectangle aqueduct structure and fluid, include pressure on the tank wall ,free surface height and so on.

本文应用大型通用有限元软件ADINA探讨了计入流体的粘性、大幅晃动影响，不可压缩粘性流体与矩形渡槽弹性体的二维动力耦合问题，分析流体的大幅晃动对矩形渡槽结构所带来的动力影响问题；在水平谐波激励方式下，针对不同的激励振幅和激励频率，研究渡槽结构和水体的振动反应包括渡槽结构的倾覆力和倾覆力矩，水体自由液面角点的波高和水体底部角点的动水压力的反应分析。

This approach followed a novel idea: the main-lobe clutter spectrum is regular for the deviation azimuth of clutter is corresponding to its Doppler frequency, while the returns of moving targets violate this regularity, so it\'s reasonable to use the azimuth error in each Doppler channel as a detector of ground moving target.

该方法以一种新的思路，利用单脉冲雷达和波束主杂波谱区固定回波的偏角与多普勒频率相对应的规律性，将动目标回波视为对这种规律性的干扰，从而利用单脉冲测角误差在主杂波谱区进行地面极低速动目标检测。

This problem is also important and valuable in Nonlinear Optics. It will be very helpful to understand how the aberrations affect the course of three- wave mixing, such as the change of conversion efficiency, the distribution of intensity and phase.Small signal solution of aberrated second harmonic generation is deduced from three-dimension three wave coupling functions. The numerical work gives out lot of results of different aberrations. The effects of the fundamental waves aberrations, which will change the conversion efficiency, distribution of intensity and phase in the frequency conversion, is analyzed. It shows that when walk-off and diffraction effects could be ignored approximately estimation of the phase distribution of second-harmonic wave could be done. The far field divergent angle and second moment radius of harmonic wave will vary with the aberration of fundamental wave, but the far field divergent angle will be obviously smaller than that of fundamental wave. The phase distribution of both fundamental and harmonic wave is measured using Hartmann-Shack wave front sensor in the experiment with 1064nm and 790nm lasers, respectively. Results are given.

首次从三维三波相互作用方程组推导得到了位相畸变光束倍频的小信号解；通过建立国防科学技术人学研究生院学位论文三维数值模型，编写相应仿真程序，首次得到了位相畸变光束倍频过程的大量计算结果，深入细致地研究了位相畸变光束经非线性光学频率变换后谐波的转换效率、光强分布、位相分布以及影响它们的各种因素；得出谐波的远场发散角和光斑二阶矩的变化规律会因为基波像差的不同而不同，但谐波的远场发散角明显地比相应基波的小的结论；得到了在走离效应和衍射效应等影响许多因素可以忽略的情况下，位相畸变传递到二次谐波的估算式；举例分析了KDP三倍频方案中，基波位相畸变对二次谐波和三次谐波的影响；实验工作中，用哈特曼一夏克传感器分别对IO64nm倍频过程和790飞秒超短脉冲倍频过程中的基波和谐波的位相分布进行了测量，给出了相应结果。

Small signal solution of aberrated second harmonic generation is deduced from three-dimension three wave coupling functions. The numerical work gives out lot of results of different aberrations. The effects of the fundamental wave's aberrations, which will change the conversion efficiency, distribution of intensity and phase in the frequency conversion, is analyzed. It shows that when walk-off and diffraction effects could be ignored approximately estimation of the phase distribution of second-harmonic wave could be done. The far field divergent angle and second moment radius of harmonic wave will vary with the aberration of fundamental wave, but the far field divergent angle will be obviously smaller than that of fundamental wave. The phase distribution of both fundamental and harmonic wave is measured using Hartmann-Shack wave front sensor in the experiment with 1064nm and 790nm lasers, respectively. Results are given.

首次从三维三波相互作用方程组推导得到了位相畸变光束倍频的小信号解；通过建立三维数值模型，编写相应仿真程序，首次得到了位相畸变光束倍频过程的大量计算结果，深入细致地研究了位相畸变光束经非线性光学频率变换后谐波的转换效率、光强分布、位相分布以及影响它们的各种因素；得出谐波的远场发散角和光斑二阶矩的变化规律会因为基波像差的不同而不同，但谐波的远场发散角明显地比相应基波的小的结论；得到了在走离效应和衍射效应等影响许多因素可以忽略的情况下，位相畸变传递到二次谐波的估算式；举例分析了KDP三倍频方案中，基波位相畸变对二次谐波和三次谐波的影响；实验工作中，用哈特曼-夏克传感器分别对1064nm倍频过程和790飞秒超短脉冲倍频过程中的基波和谐波的位相分布进行了测量，给出了相应结果。

A new algorithm is presented to estimate the azimuths,elevations and Doppler frequencies of uncorrelated signals incident on a uniform circular array.

本文研究均匀圆形阵列的信号处理问题，提出了一种同时估计空间非相关信号源方位角、俯仰角和多普勒频率的算法。

The problem of joint estimation of the frequency, angle of arrival and polarization with crossed dipoles is investigated.

研究了利用四阶累积量方法估计信号的到达角、极化角和频率。

The torque me asurement experiment in hand tappin g shows that suitable tapping motion w ith high frequency can remarkably re duce tapping torque,and the dominating parameters in hand tapping are cutti ng angle and separating angle,which laid a foundation for the study on vib ration tapping and its popularization and a pplication.

对手动攻丝这种极限振动攻丝过程的扭矩测试结果表明，丝锥对工件的低频、低速往复切削作用也可以使攻丝扭矩显著下降。这表明影响手动攻丝扭矩的主要因素不是振动频率或冲击的大小，而是切削角和分离角的大小，这为进一步究明振动攻丝的机理及促进振动攻丝技术的推广应用奠定了基础。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。