宽频带

Level of serum total cholesterol and triacylglycerol of patients in the plaque group was in a normal range (4.45±0.98),(1.36±0.60) mmol/L superior limit of mon carotid artery of patients with or without plaque in thyroid: Frequent zone was 10 cm/s or so in the wider ones and all with sound window.

有斑块组患者的血清总胆固醇、三酰甘油水平均处于正常范围内[(4.45±0.98)，(1.36±0.60)mmol/L(正常值上限：5.2 mmol/L；2.25 mmol/L)]。③甲状腺段颈总动脉有无斑块患者的频谱参数：频带较宽为10 cm/s左右，都有声窗。

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。

Making use of field matching method,combining with the variational method,the dispersion equation of the ridge loaded ring plane slow wave structure and small signal gain of this type of TWT are presented in this paper.

脊加载环板行波管是一种频带相对较宽的大功率行波管，本文用场匹配和变分原理相结合的方法，研究了脊加载环板慢波结构的导波特性及这种行波管的小信号、大信号特性，讨论了结构的几何尺寸及电子注参量对慢波的传播特性、小信号增益及注波互作用非线性效应的影响。

Doesn't be processed and direct is adopted analog-to-convert,the dyn amic range of analog-to-digital converterin data acquisition circuit can't match the need of GPR system and the problem will affect the exploration depth and resolution of GPR.

探地雷达回波信号具有动态范围大、频带宽等特点，如果不对回波信号进行处理直接进行A／D转换，则会出现动态范围不匹配的问题，严重影响雷达的探测深度和分辨率。

Research and analysis were carried on frequency spectrum characteristics of loaded coal 's EME during deformation and fracture process.

对受载煤体变形破裂时电磁辐射的频谱特征进行了研究分析，研究结果表明，在受载煤体变形破裂过程中电磁辐射的频带很宽，其主频段随载荷的变化而发生变化，在受载初期，电磁辐射的主频带较低，电磁辐射主频带有时呈现先增高而后降低的趋势；在受载后期，电磁辐射的主频带较高，基本上表现为载荷越大，电磁辐射的主频段越高。

By using the lightning current's expression recommended by IEC1312-1, we calculate and analyze the electromagnetic field near the lightning channel, and discuss the influence of the electromagnetic field distribution due to the finitely conductive ground.

对IEC1312—1中推荐的雷电流表达式进行了频谱分析，发现其代表的雷电流的频带很宽，但雷击释放的能量主要集中在低频部分。

With the development and application of three-terminal devices, a millimeter-wave three-terminal device oscillator has some advantages over a two-terminal oscillator, for instance, operation frequency band, efficiency, stability and integrity. Especially, for PHEMT (pseudomorphic high electron-mobility transistors) oscillator and HBT (heterojunction biplor transistors) oscillator, there is lower noise and better integrity, operate in wider dynamic range and higher frequency band.

随着三端器件的发展，相对于毫米波二端器件振荡器而言，毫米波三端器件振荡器具有工作频带宽、效率高、工作稳定和集成度好等优点，特别是用PHEMT和HBT器件制作的振荡器，具有更低的噪声，更大的动态范围，更好的集成度，可以工作在更高的频段，所以固态器件毫米波振荡器已逐步向三端器件振荡器发展。

The production can use as realia and scientific research instrument. DDS ; FPGA ; AVR MCU ; signal modulate

其特点是频带宽、精度高、性能稳定、成本低，可作为电子设计培训课程中的教具，也

It possesses the advantages such as small volume , wide transmission belt of frequency , no saturation problem and without harmonic vibration point etc.

采用电阻分压器来替代电磁式电压互感器，可将初级电压直接转化为10 V 以内的微信号，具有体积小、传输频带宽、不存在饱和问题、无谐振点等优点。

Being characteristics of the broad transmission bands an...

由于传输线变压器具有通频带宽、易于制作的特点，在功率超声领域将有可能得到广泛的应用。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。