高频率的

Objective To study the power spectrum density of blood flow ultrasonic Doppler signal using wavelet analysis. Method Doppler signal of blood flow in human common carotid artery was studied with wavelet scalogram analysis, an affine smoothing Wigner Ville transform with a constant "Q" character. Result Wavelet scalogram of blood flow ultrasonic signal had a higher distinguishability than STFT spectrogram in the low frequency portion, but had poorer decussation terms than spectrogram.

对于平稳信号的处理工具仍然是Fourier变换，但是，在实际应用中的绝大多数信号是非平稳的，现在看来处理非平稳信号的主要工具将是小波变换，这主要是因为传统的Fourier变换分析信号时，时间和频率分辨率精度是固定不变的，而利用小波变换分析信号，在信号高频段时间分辨率精度也较高，在信号低频段频率分辨率精度较高，这很符合非平稳信号的特点。

Results: Primary glaucoma invasive age from 60-70 was crest-time, it was 41.60% of sum; female patients were majority, it was 62.18% of sum; spring is high incidence time, it was 36.13% of sum; primary glaucoma was chronic disease, averaged course was two years-two months; usual symptom are hyperpyrexia of liver (34.03%), stagnation of QI due to depression of the liver (17.23%), hepatic and renal yin deficiency (13.45%), asthenic yin causing excessive pyrexia (11.76%), upward invading of wind-fire disturbing eye (11.76%), asthenic yin causing predominant yang (9.24%); inpairment of vision, eyes pain, shallow of anterior chamber were usual complaint and physical sign; using frequency usual prescription from hing to low were: hoelen, isapgol, anemarrhenae, glycyrrhiza uralensis, alisma rhizoma, cortex moutan, etc.

结果：原发性青光眼发病年龄以60~70岁最多见，占总例数41.60%；性别中女性患者居多，占62.18%；发病时间以春季最多，占总病例数36.13%；本病以慢性发病为主，病程平均为2年2个月；常见证候为肝火上炎证(34.03%)、肝郁气滞证(17.23%)、肝肾阴虚证(13.45%)、阴虚火旺证(11.76%)、风火上扰证(11.76%)、阴虚阳亢证(9.24%)；视力下降、旅胀痛、前房浅等较为常见的症状与体征；常用方使用频率由高到低依次为绿风羚羊饮、六味地黄汤、逍遥散等；常用药物使用频率由高到低依次为：茯苓、车前子、知母、甘草、泽泻、丹皮等。

Use of Chinese young learners is in the medium range;(2) among the six strategy categories metacognitive strategies are the most frequently used whereas compensation strategies are theleast frequently used;(3) there exists statistically significant difference between female and male young learners in language learning strategy use; and (4) there is a positive correlation between young learners' language learning strategy use and their language proficiency.

其中，元认知策略的使用频率最高，补偿策略的使用频率最低；(2)男、女生在学习策略的使用上存在显著差异，无论是在总体上还是六种策略的使用上，女生都比男生的使用频率高；(3)成功的英语学习者学习策略的使用频率最高，其次是水平一般的学习者，不成功的学习者学习策略的使用频率最低。

However, please be noted that high sensitivity will allow the interfusion with exterior noise irrelevant to the quantity to be measured, which will be also amplified by the system.

传感器的频率响应高，可测的信号频率范围就宽，而由于受到结构特性的影响，机械系统的惯性较大，因有频率低的传感器可测信号的频率较低。

Also, the aborigines suffering from general chronic diseases (diabetes, hypertension, and hyper lipemia) tend to make more frequent clinic visits than the Han people do.

在一般慢性病（糖尿病、高血压、高血脂）之就医频率上，原住民显著高於汉民族；而就医频率偏高的主要原因之一乃为疾病控制不好，需有较频繁的门诊医疗照护。

In recent years, SiC FET power transistor and GaN high electron movability power transistor represent the third generation semiconductor-wide bandgap semiconductor power devices, have advantages of high breakdown voltage, high power density, as well as high output power, high operation efficiency, high operation frequency, wide instant aneous bandwidth, operation in high temperature environment and strong ability of resisting radiation.

近年来以SiC场效应功率晶体管和GaN高电子迁移率功率晶体管为代表的第三代半导体－宽禁带半导体功率器件具有击穿电压高、功率密度高、输出功率高、工作效率高、工作频率高、瞬时带宽宽、适合在高温环境下工作和抗辐射能力强等优点。

The frequency of a sound is the number of cycles per second of a sound wave.

所谓频率，就是一个声浪每秒种的周率，声音频率越高，音节就越高。

The main content of this dissertation includes: 1. Research on the theory of ultrasonic power supply, introduce its development process. On the basis of these, fix on the scheme of medical ultrasonic low-power supply. 2. According to the principle of modularized design, divide medical ultrasonic low-power supply into four parts. They are power amplify circuit, power control circuit, frequency automatic tracking circuit and matching circuit. Separately research on their theories and design their circuits and necessary programs, especially, effectively resolve the problem tracking the supersonic vibration system with a narrow syntony frequency bandwidth and a high swing. 3. The matching experiments gain good result, and prove that medical ultrasonic low-power supply is entirely up to the mustard on intellectualization, wide band of working frequency, steady output and high efficiency.

本文工作的主要内容包括： 1、研究了超声功率电源的原理，并回顾了它的发展过程，在此基础之上确定本文医用小功率超声电源的设计方案； 2、按照模块化的设计原则，将医用小功率超声电源的设计分解为功率放大电路、功率控制电路、频率自动跟踪电路和匹配电路等四个部分，分别研究了各部分的原理，在此基础之上进行了具体的电路设计和程序设计，尤其是有效地解决了对谐振频率带宽窄振幅高的超声振动系统的频率跟踪问题； 3、通过与超声振动系统的各项配合实验，取得了很好的实验结果，验证了医用小功率超声电源完全满足智能化、工作频带宽、输出功率稳定、输出效率高的设计要求。

The minimum fluidization velocity has a minimum value when the frequency of sound waves is 120Hz and it will decrease as the sound pressure level increases. The degree of sound attenuation will increase while bed material is higher and the fluidization quality of fine particles will become poor and the minimum fluidization velocity will increase. Compared with TiO2, the SiO2 fine particles have a better quality of fluidization at the same fluidized conditions.The cluster/subcluster model and oscillators model are used to describe the fluidization characteristics of fine particles in a sound-assisted fluidized bed. The theoretical calculations show that the minimum fluidization velocity umf is decreased with the SPL increased at the same frequency of sound and the quality of fluidization is better.

论文还系统的考察了声压和频率对纳米SiO2和TiO2颗粒流化特性的影响，结果表明：在频率一定的情况下，声压越高，流化床中形成的聚团尺寸越小，最小流化速度越低，流化质量越好；当声压低于120dB时，声场对超细颗粒流化特性的影响减小，当声压大于130dB时，则能显著改善流化效果，使流化床内的颗粒聚团明显减小，最小流化速度明显降低，粉体带出减小；声压一定，频率为120Hz左右时，最小流化速度最低，此时流化床中形成的聚团尺寸最小，流化效果最好；超细颗粒达到较好的流化状态存在一个最佳频率范围，随着声压增高，这个频率范围将增大。

Due to existing signal processing technology's shortage such aslow measurement, narrow measurement range precision and other poor performance, we introduced a high-precise signal processing technology:firstly,to get power spectrum with Hanning windowed Welch modified periodogram, search its peak value frequency;secondly, to apply zooming analysis via Goertzel algorithm;at last,to get a highly precise doppler frequency with energy centrobaric rectifying algorithm.

针对存在的缺点，本文提出了一种应用于激光多普勒测速的高精度信号处理技术，即首先利用加Hanning窗的Welch修正周期图算法得到信号功率谱，搜索其谱峰值频率，接着利用Goertzel频谱细化算法对搜索的谱峰进行细化分析，再引入能量重心频谱校正算法对细化后的谱峰进行校正分析，从而将离散频谱分析算法、频谱细化算法和频谱校正算法三者有机结合起来，充分发挥各自的优点：通过加Hanning窗的Welch修正周期图算法快速得到功率谱及峰值频率，通过Goertzel算法获得分析频带的高分辨率频谱，然后通过能量重心校正算法对细化后的频谱进行高精度校正，这样不仅保证了算法的高效性，而且大大提高了分析的精度。

She gently rebuff ed him, but agreed that they could be friends

她婉言拒绝了，但同意作为朋友相处。

If in the penal farm, you were sure to be criticized.

要是在劳改农场，你等着挨绳子吧！