查询词典 frequency bandwidth

Linear frequency-modulated pulse is one of the most important large time-bandwidth product signals, but it demands large amount of calculations for digital processing.

针对TMS320C6201的特点，提出了在VLIW体系结构下，提高FFT并行运算效率的方法，从而使系统完成512点数字脉冲压缩的时间仅为124us，基本达到TMS320C6201的性能极限。

Pseudo-random multi-frequency signal is invented and named by academician He Jishan. The bandwidth of PRMF signal is controllable, it's energy concentrates on several frequencies, which are equally spaced on log scale coordinates.

何继善院士发明和命名的伪随机多频信号，由于其带宽可控，能量主要集中在数个在对数坐标上呈等间距分布的频率上，是电法勘探的理想场源。

Pseudo-random multi-frequency signal is invented and named by academician He Jishan. The bandwidth of PRMF signal is controllable, it's energy concentrates on several frequencies, which are equally spaced on log scale coordinates. It is ideal excitation source for electrical exploration.

中文题名伪随机多频电磁法观测系统研究副题名外文题名 The study on pseudo-random multi-frequency electromagnetic prospecting system 论文作者陈儒军导师何继善学科专业地球探测与信息技术研究领域\研究方向学位级别博士学位授予单位中南大学学位授予日期2003 论文页码总数165页关键词电法勘探电磁法伪随机多频信号馆藏号BSLW /2003 /P631.3 /4 伪随机多频信号由何继善院士发明和命名，该信号带宽可控，其能量集中在数个在对数坐标上呈等间距分布的频率上，是电法勘探的理想场源。

But its frequency bandwidth is in the middle (5) Metal nanotubes were prepared by heating metal-coated carbon nanofibers inthe air to remove carbon nanofiber templates.

5将镀层纳米碳纤维在空气中热处理，可以去除纳米碳纤维，获得纳米金属管。

The objective of design optimization for the current loop is to maximize the cross-over frequency. The results show the stability is improved and the capability of suppressing the switching noise is far better than the original. The objective of design optimization for the voltage loop is to minimize the gain of the line ripple voltage.As a result the bandwidth minishes obviously and optimization design excelles in restraining the ripple.

主电路以总体积最小为优化目标，优化结果表明电路的体积减少了0.5%；电流环以开环穿越频率最大为目标，优化结果表明电流环的稳定性能得到了改善，开关噪声抑制能力明显优于优化前的；电压环以线纹波电压增益最小为目标，优化结果表明电压环的带宽明显减小，纹波抑制能力远远优于优化前的。

Objective: To observe the treatment effect on port-wine stains with double frequency 532nm wavelength Nd:YAG Laser with variable bandwidth.

目的：观察倍频Nd：YAG532nm波长激光治疗鲜红斑痣效果。

The results show that:(1)the low-noise source-follower circuit can be effectively used to measure the output of PVDF thin film;(2)the piezoelectric coefficient D33 of the PVDF is very sensitive on temperatures;(3)the value of D33 intensively fluctuate in initial loading stage,this means that a pre-load is needed in practice application to keep a constant piezoelectric coefficient D33 of the PVDF;(4)when the compressive load is imposed on the surface of the PVDF along a incline direction,D33 value is obvious changed with changing incline angle,and(5)the frequency bandwidth of the PVDF thin film is very wide,it is more suitable to measure strike or impact loading at various loading conditions.

结果表明：(1)低噪声源跟随电路可有效测量PVDF 薄膜输出；(2)PVDF压电薄膜的压电系数D33对温度很敏感；(3)D33值在加载初始阶段波动很大，所以实际应用中应给PVDF提供一个预压载荷，以确保有一恒定的压电系数D33；(4)当压载荷沿倾斜方向作用在PVDF 表面时，由于有剪切力作用，D33 值会随着倾斜角的变化发生显著改变；(5)PVDF 薄膜具有很宽的频响，更适用于测定不同载荷条件下的侵彻或冲击等动态载荷。

This paper aims at the design, implementation and evaluation of an industrial brushless servomotor drive. The proportional-plus-integral speed control with gains tuned by an extension of the frequency-zone method and anti-windup PI speed control based on self-conditioning techniques are studied. The parameters of speed performance criteria, control loop bandwidth, per normal inertia, and noise sensitivity are employed to evaluate the performance of the drive.

本文针对工业用无刷伺服马达驱动器进行设计与制作，延伸频率区域法分别设计比例积分控制之增益值，以自我条件技术完成比例积分速度控制之反卷起设计，并依据速度性能准则之参数，如控制回路频宽、惯量标么值、杂讯灵敏度等，进行驱动器之性能评估。

It is indicated that only a single resonance peak appears in the amplitude versus frequency curve without spurious resonance peaks during the procedure. The direct actuation enables to improve the tuning accuracy, weaken the possible sample damage by the tip, and enhance the atomic force microscope bandwidth and imaging rate.

研究表明，采用压电探针的直接激振方法在探针振动的幅频曲线中仅有单一谐振峰，可以避免在压电陶瓷管激振方法下由液体振动造成的寄生谐振峰，因此使用压电探针不仅提高了探针振动频率的控制精度，而且减小了针尖对样品的损坏，还提高了仪器的带宽和成像速度。

Using its 3 Hz resolution bandwidth, power line sidebands below -95 dBc can typically be measured at frequency offsets of only 50 or 60 Hz.

利用其第3赫兹的带宽，电力线边低于-95 dBc的通常可以测量频率偏移只有50或60赫兹。

The quality of both red and white wine depends very much on the wine maker talent and on the quality of the grapes.

他的红酒和白酒的品质，根据酿造者的能力和葡萄的质量，各有差异。

No, I don't want to get drunk before my next match.

" "不，我不想让我的下一场比赛前喝醉了。