查询词典 spectrum analysis

Based on the analysis of the excitation spectrum, we obtain the superfluid-Mott-insulator phase transition condition, and superfluid velocity of ultracold dilute gas of bosonic atoms in an optical lattice, and point out that the velocity of superfluid can be experimentally adjusted by controlling the parameters of optical lattice.

在长波极限下，色散关系是线性的，这与无外场时的色散关系相同。从激发谱分析可得到superfluid-Mott绝缘相变条件，给出了光格子中超流速度，并指出在实验上可以通过控制光格子参数来改变超流速度。

Propagation of power spectrum density:theory and numerical analysis.

功率谱密度传输性质的理论分析与数值模拟。

The power spectrum exponent analysis indicates that there are three differ- ent intervals where the static water heights have the effect on vibration energy.

信号的功率谱指数分析表明，静态液位对振动能量的影响存在于3个区间，分别为0。

The new method for identifying trabecular patterns based on power spectrum and fractal analysis is proposed in this thesis.

本文针对这些问题通过对骨X线图象的功率谱分析和分形分析，提出了更为有效的识别方法。

Based on the analysis on primary wave frequency characteristics, some conclusions can be obtained: there were variations obviously for the characteristics of primary wave frequency spectrum in fracture zones, such as the dominant frequency shifted towards the low frequency, at this location the amplitude increased rapidly, and there were significant differences from the surrounding unbroken rocks.

通过对纵波频谱特征的分析得到这样的认识：对于断裂构造，纵波的频谱特征有着明显的变化，如纵波的主频位置向低频偏移，在低频位置上其幅度急剧地增大，与上下未破碎的岩层有着非常明显的差别。

The analysis by XRD spectrum discriminate that the magnetite, Haematite, pyrrhotite and quartz from samples are found at site6 of adjacent to steel-making furnace, supporting the conclusions from magnetic measurements.

与石英相比，磁铁矿、赤铁矿和磁黄铁矿含量的强度较弱，这与前文中提及的气溶胶浓度与主要反映亚铁磁性矿物的磁性参数呈弱负相关的结论是相符的。

According to the birefringence dispersion character of a quartz crystal,the theoretical analysis and numerical simulation about the polarization interference spectrum are given,and then a systematic way of measuring the phase retardation and thickness of the quartz wave plate ,which is based on the principle of polarization interferometry,is put forward.

根据石英晶体双折射率的色散特性，对石英波片的偏光干涉谱进行了理论分析和数值模拟，提出了一种石英波片延迟量和厚度的偏光干涉标定法。

This thesis presents detailed analysis and computer simulation of the influence of the operator's body on the performance of the portable radiophone in urban mobile environments. An approach called modified Doppler power spectrum method is proposed to study this problem.

论文提出改良式都卜勒功率频谱法、及直接分离式多重路径法来分析并模拟计算，通讯性能评估系架构在错误向量量度及位元错误率，电脑模拟使用之调变系统为数位调频及π/4-DQPSK。

The composite scattering between dielectric sea surface and a conducting plate above it is calculated by using Physical Optical method and reciprocity theorem. Meanwhile, the dependence of the plate size on the composite scattering field is considered. The Doppler spectrum and the chaotic characteristic for the time series of composite scattering field are analyzed. Finally, artificial neural networks and wavelet analysis are introduced into the study of the sea clutter to realize the purpose of target detection, the factors which affect the detection of the target are discussed and the solutions to these problems are given.

同时利用物理光学近似结合互异性原理计算了介质粗糙海面与其上方导体运动平板的复合散射，考虑了平板尺寸对复合散射场的影响，并对复合散射场时间序列进行了多普勒谱分析和混沌分析，最后将人工神经网络和小波分析引入到海杂波的分析当中，实现了海杂波中目标探测的功能并讨论了影响目标探测功能的因素以及解决这类问题的方法。

The conventional numerical simulation of a reverberant field as a launch acoustic environment was introduced. Following the reciprocity theorem used in the coupled FE-BE model, the structural response due to reverberant acoustic excitation was substituted by the sound pressure caused by force excitation on the structure, then the output response power spectrum density of the coupled model subjected to reverberant environment was evaluated based on the stochastic analysis principle.

首先介绍了传统的构建混响声场的数值模拟方法；其后利用声振耦合中的互易定理，将混响声场的激励问题转化为结构模型上力激励引起的场点声压响应问题，并采用随机分析原理，用谱分析方法推导了结构在混响声场激励下的响应计算公式；最后建立了航天器典型结构的声振耦合模型，并分别用传统方法和利用互易定理的方法进行了数值模拟。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。