查询词典 radio frequency

MD-12 is a solid high-power frequency of the two systems, there is a strong 12-inch low frequency driver and a 1-inch high frequency compression driver mounted on a continuous point of 80 degrees on X50 degree horn.

MD-12是一个高功率的坚固的二分频系统，有一个强劲的12英寸低频驱动器和一个1英寸高频压缩驱动器安装在一个持续指向性80度X50度号角上。

This paper presents a low-voltage excitation with feedback method. By pre-excitations, the vibration frequency of the sensor can be got to used as the output of the driver. The feedback signal frequency is very close to the real frequency of the sensor, so the wire can reach resonance state quickly.

本文提出一种反馈式低压激振方法，降低拨弦激振电压对传感器进行预激振，将反馈的振动频率信号作为输出，对传感器进行复振，可以在很短时间内使振弦达到共振状态。

Experiment shows that any liquid has its own especial electrical resonance frequency, and electrical resonance frequency is related with the characters of the liquid itself. As soon as any of the characteristics of the liquid changed such as component,thickness,density and viscidity,the frequency of the liquid electrical resonance will changed.

利用液体的这种电谐振特性，我们来测量血浆凝固过程中谐振频率的变化；当血浆任何性质发生变化，那么这时的血浆已经不是原来的血浆了，其谐振频率一定会发生变化。

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。

The results of the study are as follows: 1 Wigner′s time-frequency analysis of the geoacoustic signal is of a clear physical meaning, which can be described as the energy distribution in time and frequency domain, and can reveal the frequency spectrum essential features of non-stationary geoacoustic signal.

研究表明：1。地声信号的Wigner时-频分析具有明确的物理意义，它可表述为信号在时间和频率域上的能量分布，揭示了非稳态地声信号频谱的本质特征。

Therefore the dispersion curves obtained in the field are primarily consisted of the first mode. For a heterogeneous elastic solid consisting of three homogeneous layers whose interlayer has low velocity, the phase velocity V〓 of the first mode will also close up to the Rayleigh wave velocity of the bottom layer when frequency f→OHz, but V〓 of the first mode will close up to the shear wave velocity of the interlayer when f→∞, and there is a cut-off frequency at high frequency region for the first mode and V〓 close up to the compressional velocity of interlayer when interlayer is liquid.

当三层固体介质中存在软夹层时，若f→OHz，则其基阶模式的相速度V〓→V〓（V〓为最底层介质的瑞利波速度）；若f→∞，其基阶模式V〓→V〓（V〓为中间层介质的横波速度）；若三层介质中存在液体夹层，当f→OHz时，基阶模式V〓→V〓，而基阶模式在高频段存在一个截止频率，截止频率处的瑞利波速度V〓→V〓；由此可判定，野外实测的相速度频散曲线不仅有基阶导波模式，同时还应有高阶导波模式波的存在，接收信号中存在模式间的跳跃，因此频散曲线会产生"之"字形现象。

Holding the input energy and actuator volume fixedness, the active frequency has no effect on jet velocity. But the recovery stage time shorten with the increase of active frequency. So, the choice of active frequency is under consider of the temperature resistance for actuator.

在输入能量和腔体体积不变时，激发频率的提高对合成射流的最大速度没有明显的影响，但缩短了腔体内气体的冷却时间，实验时对激发频率的控制首要考虑腔体的耐温能力。

Characterization of the nature of the forced vibration amplitude of the forced vibration frequency and phase frequency characteristics (amplitude and phase frequency characteristics).

表征受迫振动的性质是受迫振动的振幅频率特性和相位频率特性。

A set of complex Morlet wavelet are applied on projection slice of each direction to decompose each projection into several frequency channels,the average and variance extracted are computed in each frequency channel,and then linear regression model is employed to computer realationship feature between frequency channels.1-D DFT is applied to features and the amplitudes of Fourier coefficient are selected as features,then the extracted features are rotation invariant.

该算法是将一定大小的图像进行二维傅里叶变换；其次在变换后的图像中央选择一个圆盘区域，并在方向［0°，180°］内进行等间隔角度频率抽样，实现方向分解，使用一组复Morlet小波对每个方向上的映射切片进行小波变换，从而实现多通道频率分解；在各个频率通道中计算均值和方差作为特征，并利用线性回归模型计算频率通道之间的关系特征；将特征沿方向进行一维傅里叶变换并取其幅值，从而得到旋转不变性特征。

The high efficiency transistor development causes the frequency changer the construction cost more and more to be also low, from the cost and the performance considered selects PLC to the frequency changer control realization frequency conversion velocity modulation.

大功率晶体管的开发使变频器的造价也越来越低，从成本和性能考虑选用PLC对变频器控制实现变频调速。

Listen,point and check your answers.

听，指出并且检查你的答案。

Warming needle is one of effective treatment methods for knee arthralgia aggravated by cold,and it is simple,safety,so it should be developed in clinical acupuncture and moxibustion extensively.

但以本院科针灸门诊在2005年1月—2006年6月期间共收治膝痛患者100余例，经过临床的诊断后，其中施以温针治疗的48例，疗效显著，报道如下。1临床资料本组病例48