查询词典 coherent order

In order to study the grating diffractive field's characteristics of the partially polarized and coherent beams, an analytic expression of polarization degree and angular correlation of partially ploarized and coherent beams through polarized gratings is derived based on the beam coherentce-polarization matrix approach of partially coherent beams.

为了研究部分偏振部分相干光光栅衍射场的衍射特性，利用部分偏振部分相干光的光束相干-偏振矩阵，推导出了部分偏振部分相干光通过任意偏振光栅后，衍射场的偏振度及场中衍射级次角相关的一般解析表达式。

The results suggest that the electron density of the interface between GP zone and the matrix is coherent under the first order approximation, thus particles of GP zone are prone to growing, while β phase is not coherent, which will restrain recrystalization particles of β phase from growing, however β phase is coherent to enhance resistance to deformation of the alloy under high stress.

结果表明：Al-Mg-Si合金GP区与基体界面电子密度在一级近似下连续，GP区粒子易于长大，而β相不连续，抑制了β相再结晶晶粒的长大，但它在高应力下呈现连续，从而提高合金变形抗力。

The dynamic course of multi-scale coherent eddystructures'bursting is researched. A periodic blowing/suction forcing, issued from a thin latitudinal slot onthe wall, is introduced to alter multi-scale ingredients of coherent eddystructure and their energy distribution in turbulent boundary layer, what ismore, to perturb and control the coherent eddy structures in order toaccomplish drag reduction of skin friction.

在平板湍流边界层的固壁表面沿展向开一条窄缝，用以施加局部周期性抽吸扰动，改变平板湍流边界层中不同尺度相干结构的能量分布、条件相位平均波形、平坦因子和猝发频率，从而对平板湍流边界层中原有的多尺度相干结构进行干扰和控制，以达到壁面减阻的目的。

The dynamic course of multi-scale coherent eddystructuresbursting is researched.A periodic blowing/suction forcing, issued from a thin latitudinal slot onthe wall, is introduced to alter multi-scale ingredients of coherent eddystructure and their energy distribution in turbulent boundary layer, what ismore, to perturb and control the coherent eddy structures in order toaccomplish drag reduction of skin friction.

在平板湍流边界层的固壁表面沿展向开一条窄缝，用以施加局部周期性抽吸扰动，改变平板湍流边界层中不同尺度相干结构的能量分布、条件相位平均波形、平坦因子和猝发频率，从而对平板湍流边界层中原有的多尺度相干结构进行干扰和控制，以达到壁面减阻的目的。

Secondly, 4 methods of azimuth estimation based on vector hydrophone according to forms of nosie and signal are brought forward. The principles of these 4methods are set forth, simulating them by computer. Acoustic intensity averager can effectively suppress isotropic non-coherent interference; DOA based on line-spectra can effectively detect the target radiating line-spectra and estimate its azimuth angle; Bar graph approach can suppress line-spectra coherent interference and distinguish different targets radiating line-spectrum. Weighted bargraph approach can detect target in broadband coherent interference and estimate its azimuth angle.

其次，根据背景干扰和信号样式的不同，提出了单矢量水听器方位估计的4种方法；阐述了这4种方法的原理，并进行了计算机仿真，指出平均声强器方位估计适用于各向同性噪声场背景干扰，讨论了平均声强器的处理增益；目标辐射噪声中有线谱时，线谱方位估计有很好的性能，其中的LOFAR线谱和高频解调得到的DEMON线谱都是目标的特征谱线，可以利用它们进行方位估计，详细讨论了利用特征线谱单个矢量水听器分辨多目标的性能；直方图方位估计能抗强线谱相干干扰；加权直方图方位估计可以抗宽带相干干扰。

It was found that the residual pulsant Reynolds stress term of coherent structures has the same order of magnitude with the Reynolds stress contribution term of random fluctuation and can not be ignored in the dynamic model of coherent structures. This is not as that estimated before.

研究发现，相干结构剩余脉动雷诺应力项在数值上具有和随机脉动对相干结构贡献的雷诺应力相同的数量级，表明在相干结构动力学模型方程中，相干结构剩余脉动雷诺应力项并不像以前佑计的那样可以忽略不计。

By time-varying filtering, we realize the signal selectivity and interference suppression, especially for the signals with time-varying power spectrum. It is shown herein that conventional eigenstructure based methods are lower dimensional special case of the time-frequency subspace fitting method. The closed-form array response estimation algorithms for blind source separation in wireless communication is also developed in the dissertation by exploiting the data structure of second-order statistics of the array output in the presence of multipath. The proposed method achieves array response estimation with little constraint on signal property and propagation environment such as scatters or angular spread. Moreover, the array utilized here can be of arbitrary geometry and even uncalibrated. Since the closed-form solution is obtained, no misconvergency may occur and large amount of computation can be saved. The equivalent feed model and corresponding optimization designation are proposed to realize the downlink multi-user selective transmission. By coherent and non-coherent superposition of the electromagnetical field, multiple beams can be formed using a single array, so that each co-channel user signal is transmitted in each beam and will not interfered with each other. The proposed system scheme implements the digital beamforming and the channel allocation in the base band, therefore is suitable for the utilization of the radio software technology. The feasibility and effectiveness of the proposed model are proved by the RF experiment.

在窄带条件下，GSC－SSF方法还可以提高阵列的虚拟孔径，从而提高估计的性能；可以证明，Cyclic DOA 和SC-SSF方法可看作该方法的特例或近似； 3、提出了二维GSC－SSF方法和宽带谱相关DOA矩阵方法，利用信号的循环平稳特性解决了宽带条件下二维 DOA 估计问题，并具有阵元数少、计算量较小的特点； 4、提出了时频子空间拟合和宽带时频DOA估计算法，将联合时频分析的理论和方法引入到阵列信号的空间谱估计研究中，利用时变滤波实现信号选择性测向和干扰抑制，特别适合于谱时变信号；可以证明传统特征结构法可看作是时频子空间拟合方法的特例； 5、提出了多用户环境下阵列响应的估计方法——CARE方法，该方法对信号结构和传播参数（主要是散射源分布与角度散布）的约束较少，适用于各种几何结构的阵列甚至未校准的阵列，能够直接得到阵列响应的闭式解，因此计算量小、稳健性好，不存在收敛问题； 6、提出了针对多用户下行选择性发送的阵列等效激励模型、优化设计方法及其系统实现方案，通过空间场的相干叠加与非相干叠加使得单一阵列能够形成多个波束，并保证各波束内的用户信号各不相同且相互干扰最小；其系统方案具有在基带实现数字波束成形、信道分配并便于软件无线电实现的特点，其有效性已得到外场实测数据的证实。

In this paper a new method is proposed in order to suppress the coherent interference. First, utilizing the interpolate method, the real array can be virtually shifted under coherent interference, several covariance matrice are gererated after the virtual shifting. By averaging the previous results, a new covariance matrix is obtained. It is a full rank matrix.

提出一种新的相干波束形成方法，利用内插变换对相干背景下的真实阵列进行虚拟平移，得到多个虚拟平移后的信号协方差矩阵；对其进行平均后，所得到的相干信号协方差矩阵具有满秩性。

In addition to the-coherent Stokes Raman scattering and CARS radiations, the second order coherent Stokes R...

除了观测到相干斯托克斯和CARS辐射，还观测到二级相干斯托克斯和相干反斯托克斯辐射。

However , on the other hand, quantum information processing and quantum computing need stable coherent superposed state, then decoherence is a difficulty of realizing them, it is, therefore, an important issue to find methods for slowing down decoherence in order to stabilize the coherent superpositions in the field of quantum study.

然而，另一方面，量子信息与量子计算需要稳定的相干叠加态，而退相干是实现它们的障碍，因此，为了获得稳定的相干叠加态，寻找减小退相干的方法成为量子研究领域的重要议题。

In contrast to the ubiquitous rising-sun-with-rays military flag of the Japanese, Chinese banners and ensigns feature a range of designs.

与遍地都是的太阳军旗不同，中国人的旗帜和徽章设计得各式各样。

From their small corner of Feng's Guangzhou headquarters -- a jumble of pink leashes, squeezable rubber steaks, and plastic doggy Santas for Fido's stocking -- Soleil's designers come up with at least five new products a month.

从Feng 设在广州总部的产品展示柜台上可以看到，Soleil的设计师每月至少设计出5件新产品。