频率转换

The dynamical characteristics of a low voltage MicroGrid from grid-connected mode to islanded mode with different distributed generation configuration schemes are analyzed by using simulation method,and the corresponding changing laws of each DG's power,voltage and frequency of MicroGrid are obtained.

通过算例仿真研究了不同分布式电源配置方案下低压微网从并网模式向孤网模式转换的动态运行特性，获得了分布式电源的功率、微网电压和频率的变化规律。如果选择微型燃气轮机作为微网的功率支撑手段，在微网从并网向孤网过渡过程中，系统频率波动较大，且部分分布式电源有可能在低频保护动作下与电网隔离，不利于微网的稳定运行；增加储能设备后，储能设备对于微网的稳定运行可发挥重要的作用。

A design and implementation method of the high speed modulation system, which adopted the new techniques of the FPGA and DAC based communication system,is presented in this paper. The effect of the key techniques of this system, such as the high speed digital signal processing for modulation, high speed based-band signal conversion, wide-band modulation, carrier suppression, high frequency and high precision system clock generation, is analyzed, and the solutions and performance analysis is also given. Finally, a high speed modulation system for space applications is implemented, can be used for high speed data transmission with QPSK, 8PSK, QAM or other kinds of digital modulation.

本论文依据正交调制原理，采用基于FPGA和DAC的设计技术，提出了一种高速、灵活的调制系统的设计方法，重点分析了系统组成的调制编码映射、基带脉冲信号转换、信号滤波、调制、系统时钟产生等关键技术环节的影响，解决了高速调制信号处理、高速数据转换、宽带调制、载波抑制、高频率高精度系统时钟的产生等关键技术问题，完成了一种适用于空间应用的高传输速率、多进制数字调制方式和调制体制灵活的数据传输调制系统的设计与实现，可在硬件设计不变的情况下，实现QPSK、8PSK和16QAM等多种调制方式的高速数据传输，QPSK调制速率达到500Mbps。

The one little quirk is the Channel Switch is above the Volume/Squelch and when changing frequencies, you cover the display with your hand.

一个小毛病就是：就在音量/静噪旋钮上面的频道转换旋钮，当你改变频率的时候，你就用手挡住了频率的显示。

This paper simulates how the additional flutter signal impacts on oil pressure and actuator output when the dead zone is kept. The proper principle of flutter signal for jam diagnosis is given. Based on the given flutter signal, different jams caused by jam of the EH servo valve under different operating condition are simulated and the output of the oil pressure and actuator are presented. Meanwhile, waving threshold of the oil pressure for jam diagnosis is given. The simulations and analysis prove that the jam fault identification of the EH servo valve based on flutter signal is feasible.

在应用附加振颤信号防止和识别卡涩故障的前提下，确定了振颤信号的选取原则，并采用仿真的方法深入探讨了3种变工况条件下不同卡涩程度对电液转换器油压和油动机输出的影响，提出了油压阈值的卡涩判断标准，论证了基于振颤信号幅值与频率响应监测电液转换器卡涩故障诊断方法的可行性。

For full-speed USB devices the operating frequency was low enough to allow data recovery to be handled in a vendors VHDL code, with the ASIC vendor providing only a simple level translator to meet the USB signaling requirements.

对于全速USB设备的工作频率低，足以允许数据复原转换，从而给供应商的VHDL代码处理的，通过ASIC的供应商只提供一个简单的电平转换器，以满足所需的USB信号。

Furthermore, we shall prove that a minimum theoretical sampling frequency of order 6.8 kilohertz is required to convey a voice channel occupying the range 300 HZ to 3.4 Khz.

而且，我们将证明，为了转换频率范围为300HZ—3.4KHZ的话路信号，理论上最小采样频率须为6.8khz。

Since the distance between these two points is 182 units, the fundamental frequency is fs/(182/5)= 16000/(182/5)= 439.56 Hz, which is equal to 68.9827 semitones.

在上述范例中，上图红线的位置代表音框的位置，下图即是 256 点的音框，其中红线部分包含了 5 个基本周期，总共占掉了 182 单位点，因此对应的基本频率是 fs/(182/5)= 16000/(182/5)= 439.56 Hz，相当於 68.9827 半音，其中由基本频率至半音的转换公式如下

The frequency synthesizer includes a completely on-chip LC VCO and a 90 degrees phase splitter for generating the I and Q LO signals to the down-conversion mixers in receive mode and up-conversion mixers in transmit mode.

频率综合者在-芯片LC VCO上-完全包含a和一产生我和 Q北美印第安人90度分相器为向挫折-转换混合者发信号示意在朝派收到方式和沿着-转换混合者在朝派传送方式。

The frequency synthesizer includes a completely on-chip LC VCO and a 90 degrees phase splitter for generating the I and Q LO signals to the down-conversion mixers in receive mode and up-conversion mixers in transmit mode.

频率合成器完全地包括一块在芯片LC VCO 并且90 程度逐步采用分离机为引起I 并且Q 低信号对下来转换搅拌器接受方式并且转换搅拌器传送方式。

Then the time-temperature shift principle is used to translate the relationships from three dimensions to two dimensions, so master curves are obtained regarding dynamic modules changing along with the frequency over 15 amount levels.

利用时温等效原理，将频率扫描试验得到的三维关系进行温－频转换，获得了跨越15个数量级的动态模量随频率变化的二维全频主曲线。

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。