查询词典 frequency band

The consistency of the results from the present method and the scatter center model method are derived from the stationary phase method in high frequency region, whereas the present method is general and suitable for the analysis of angular glint in the entire frequency band.

利用驻相法说明所提方法和散射中心建模方法在高频区的结果是一致的，而所提方法适合在全频带上分析目标角闪烁。更具一般性。

The output tuning range was 1810MHz~1930MHz, and the LCVCO used cross-coupled complementary full differential topology with switching capacitor array to cover frequency band, which could lower the VCO gain in each single band and further lower the whole PLL's phase noise performance.

LCVCO的输出频率范围满足1810MHz~1930MHz，采用交叉耦合互补全差分结构和开关电容阵列，实现多带覆盖所需频率范围，降低了单带VCO增益，进而降低了整体相位噪声。

Time-Frequency parameter estimation and direction finding for nonstationary signals impinging on an antenna array over a wide frequency band (2~18GHz) is under in-vestigation, and a new method for parameter and 2-D Angle-Of-Arrival estimation of spatio-temporal undersampled LFM sources is proposed in this paper.

摘要针对宽频段(2-18GHz)内非平稳来波信号的参数估计和测向问题，提出一种时空欠采样线性调频信号参数与二维到达角联合估计方法。

The simulation results indicate that H_∞mixed sensitivity controller with PI current loop can improve the capability of low frequency noise enhancement and high frequency enervation in wide frequency band, and attenuate noise of torque sensor. The designed control system for EPS system exhibits good robust performances in assist tracking and anti-disturbance, greatly enhances the returnability, driver\'s steering feel, handling characteristic.

通过仿真结果分析表明基于PI电流环的混合灵敏度鲁棒H_∞控制器能在较宽频带范围内增强地面低频信号、削弱高频信号和抑制转矩传感器的噪声，所设计的控制器有较强鲁棒性，助力跟踪能力和抗干扰能力，能有效改善车辆的转向回正特性，提供给驾驶员较为满意的路感，提高车辆的转向操纵性能。

HIGH FREQUENCY, The frequency band between 3 and 30 MHz.

高频， 频率带在3至30兆赫之间。

In chapter 4, the Newlands harmonic wavelet is improved and a new type of wavelet with better time-frequency characteristic is constructed. Frequency band of signal can be divided arbitrary with the improved harmonic wavelet so that the phenomena of aliasing are reduced. Several typical fault signals in Electromechanical System are analyzed with it. In addition to the improved harmonic wavelet in chapter 4, a new half-complex wavelet is presented to improve the complex wavelet, which is given by Chaari.O. A unilateral recursive algorithm is derived to improve the real-time characteristic. A parameter n is imported to make the time-frequency and filtering characteristics of it better and its ability of extracting fault feature is enhanced.

第四章通过对Newland谐波小波的改进构造频域紧支撑、时域性能良好的新型小波函数，可实现信号频带的任意划分，从而减少频带混叠现象，采用改进的谐波小波对多种典型的机电系统故障信号进行了分析；以Chaari.O复小波为基础构造了一个半复小波，从提高复小波算法的实时性出发，推导了半复小波单向递推算法，通过给原小波设置可调参数的方法，实现了一种能满足小波基本条件的复值小波，可以通过参数的调整调节小波滤波器在Hilbert空间的时频特性和相应的滤波性能，以加强半复小波对故障特征的提取能力。

It is found that the change of the frequency characteristics of chaotic system occurs mainly at the frequency band of the chaotic system, in which the input signal exists. The amplitude of the input signal doesn't influence the distortion of the output signal when masking signal is extracted by Oppenheim's chaotic masking.

研究发现，混沌系统频率特性的变化主要发生在输入信号的频率位於混沌系统频带内的情况下；输入信号幅度的大小，不影响输出信号的失真。

The working load of engin e in plowing can be taken for stable and normal random load whose power spectrum peak value is below 2 Hz. The working load of engine in rototilling contains bo th periodic element whose fundamental frequency is rotating speed of the blade s haft and normal random load of which the parts of energy centers in fundamental frequency and others are distributed over wider frequency band.

证实了犁耕作业发动机的载荷可以认为是平稳的正态分布的随机载荷，其功率谱曲线的谱峰在低于2 Hz处；旋耕作业发动机的载荷是兼有随机成分和周期成分的动态载荷，其中周期谐波的基频为刀轴转速，随机成分一部分能量集中于基频以内，部分分布于较宽频率范围。

The main peaks of the EEG power spectra were in delta and theta frequency range. In the stage of ethanol exposure, the rats exhibited much more act of attack than the control, the alpha waves of EEG decreased, while the delta waves increased. The EEG power spectra analysis showed the delta power increased and the theta power decreased. In the stage of ethanol withdrawal, the rats showed some withdrawal behaviors such as wet dog shakes, sniffing, groomingand tonic-clonic seizures for audiogenic stimulus. Spikes and spike-slow waves were found in the EEG. In power spectra analysis, the delta power decreased while the alpha and the theta power increased, the EEG frequency band moved to the high-frequency rang. These changes were found obviously on the sixth day and disappeared on the 1 Oth day after the ethanol was removed.

本研究发现：1、对照组大鼠行为无异常，伏核EEG以α节律为主，散在出现δ和θ节律；功率主峰在δ和θ频段范围，整个过程中未发现手术对伏核EEG及脑电功率谱有影响。2、在慢性饮酒过程中，大鼠攻击性行为增加，伏核 EEG的α节律明显减少，散在出现的高幅慢活动δ波逐渐增多，功率谱分析表明δ频段功率百分比明显增加，而θ频段功率百分比明显减少，总功率减少。3、停饮后，大鼠出现湿狗样抖动、打喷嚏等撤药综合症，并且高频声音刺激能引发惊厥；伏核EEG出现棘波和棘慢综合波，并持续增多，功率谱分析显示δ频段功率百分比 5 南京医科大学硕士学位论文逐渐减少，而0和以频段功率百分比逐渐增加，总功率增加。

DG1000 operates direct figure to synthesize science and technology, the random that can output an user to be defined oneself is undee, have rich input output, and frequency meter of high accuracy, broad frequency band, frequency limits 100MHz arrives 200MHz, frequency resolution achieves 6 / second.

DG1000操作间接数字分解科技，可输出用户自界说的任意波形，领有丰硕的输入输出，以及高精度、宽频带频率计，频率规模100MHz到200MHz，频率分辨率达到6位/秒。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。