查询词典 vision frequency

It Composes 40 PLC control section. It adopts a module of DVP02DA-S (2 group simulation quantity output module) to control main frequency conversion and fluctuation frequency conversion actuation. The machine also adopts a delta TP04-AS2 Text display monitor carrying on the system external input with to reel thread the data monitoring. Use plate alternating current machine driver VFD-B-P series frequency changer control master drive electrical machinery and ring board electrical machinery.

该机型整个控制系统采用了一套台达DVP14SS11R控制单元，配DVP16SP11R扩展模块（16点I/O扩展），来组成40点PLC控制部分，采用一块DVP02DA-S（2路模拟量输出模块）分别控制主变频和升降变频驱动，同时采用台达TP04-AS2文本显示屏进行系统外部输入与纺纱数据的监控，使用台达VFD-B-P系列变频器控制主传动电机和钢领板电机。

According to the importance of frequen-cy in power system operation,the authors tested andcalculated the frequency attenuation time constant Tfand the static load frequency coefficient KL,whichcharacterinze the frequency variation of power system.

根据电网频率运行的要求，对表征电网频率特性的频率衰减时间常数Tf、静态负荷频率调节系数KL进行了试验研究和理论分析计算。

The receiver's high-current capability enables it to effortlessly drive even difficult loudspeaker loads, while ultrawide bandwidth provides far superior phase linearity, lower distortion, greater high-frequency headroom, and more accurate frequency response in the audible frequency range.

接收器的高电流能力，使它能够毫不费力地驱动扬声器甚至难以负荷，同时提供超带宽远远优于阶段线性度，低失真，更多的高频率余量，以及更准确的频率响应的发声频率范围。

The transmit part adopts the phase-locked loop pattern of frequency synthesizing technology and uses the MC145152 and MC12022 chips to compose the phase-locked loop.It locks the frequency of the carrier-wave at 35MHz.The stabilization of the carrier-wave can be 4×10-5,the accuracy can be 3×10-5.The frequency modulation and the confection of the carrier-wave are realized by the capacity-changing diode V149 and the integration voltage-control oscillator MC1648 chip.The end power amplifier uses the audion 2SC1970 to make it work in the third magnifying state,it improves the efficiency of the magnifier and the power of the output reaches the design demand.

发射部分采用锁相环式频率合成器技术， MC145152和MC12022芯片组成锁相环，将载波频率精确锁定在35MHz，输出载波的稳定度达到4×10-5，准确度达到3×10-5，由变容二极管V149和集成压控振荡器芯片MC1648实现对载波的调频调制；末级功放选用三极管2SC1970，使其工作在丙类放大状态，提高了放大器的效率，输出功率达到设计要求。

Fast Fourier transformation and autoregressive model estimation, are the most common methods used in the frequency domain analysis. The fluctuation in the highfrequency bands are mediated by parasympathetic control, whereas the fluctuation in the low frequency bands are mediated by both sympathetic and parasympathetic nervous systems. The origin of the fluctuation in the very low and ultra low frequency ranges are less obvious.

频域分析法一般是利用快速傅位叶转换或自动回规模型估计法，高频处的变异是由副交感神经系统调控，低频处的变异则是由副交感神经系统共同调控，至於极低频处与超低频处的变异，其原因尚待厘清。

This frequency stabilization system is a self-adaptive thermal compensated frequency stabilization system, which is based on 80C196 single-chip-processor and uses the beat frequency lock as the criterion.

通过该系统的稳频，激光器的拍频稳定度达到1.05%，由于进一步的测试设备正在采购中，光频的稳定度和复现性尚未测量。

The performance of EFT is investigated, which indicates that time-frequency distributions using single-sided window could not accurately trace the variation of the instantaneous frequency, since their performance depend only on the history of the signal, so they are biased frequency estimator.

提出了基于对称阵元互Wigner分布平均的瞬时频率估计算法，这种方法利用多通道数据对时频分布的瞬时频率估计方法的性能进行了有效的改善，并且能够在低信噪比的条件下获得良好的估计效果， 6。

Aiming at the project request, the paper firstly introduces the theory of Frequency Hopping Communication, the theory of sampling and the principle of spectrum analysis using discrete Fourier transform, then combined with the characteristic and superiority of FPGA designs a channelizing detection method for the carrier frequency in Ultrashort Frequency Hopping signal based on FPGA.

然后结合现代可编程器件FPGA的特点与优势，设计了一种基于FPGA技术的信道化电子侦察方案。

This article first antenna, microstrip theory, the circular polarization technology, the theoretical discussion, in this based on the microstrip antenna of circular polarization method - corner square microstrip antenna, and has done a design simulation , and then do the design and further research to improve and eventually get a resonant frequency (S11 reflection coefficient corresponding to the minimum frequency) for the 1.5GHz and 1.43GHz, the frequency of circular polarization for the 1.46GHz, S11 is less than -10dB relative bandwidth, the VSWR is less than 2 is about 8.8% relative bandwidth, axial ratio less than 3dB relative bandwidth of about 2.2% of the right circular polarization microstrip antenna design case, which proved very good the circular polarization microstrip antenna theory, also fully confirmed by a square corner design is a practical program, and select the appropriate regulation of sticks is indeed able to improve the performance of the antenna.

本文先对天线、微带理论、圆极化技术等进行了理论论述，在此基础上，提出圆极化微带天线的实现方法——切角方形微带天线，并对此做了设计仿真，后又对这一设计方案做了改进及进一步研究，最终得到一个谐振频率（反射系数S11 的最小值所对应的频率）为1.5GHz和1.43GHz，圆极化频率为1.46GHz，S11 小于-10dB 的相对带宽、驻波比小于2 的相对带宽约为8.8%，轴比小于3dB 的相对带宽约为2.2%的右旋圆极化微带天线的设计案例，从而很好的印证了圆极化微带天线理论，也充分证实了切角方形是一种切实可行的设计方案，而选取合适的调节枝则确能提高天线的性能。

Researched influence of frequency on characteristic of electromagnetic wave transmission in tunnels, and analyzed characteristic of electromagnetic wave transmission in circular, arches and curved tunnels by method of metal wave guide, and gives approximate formulas of attenuation rate. Main conclusions we obtain are as follows: in circular,rches tunnels, if frequency is higher, attenuation rate is smaller, it is beneficial for EM waves to transmit, in curved tunnel, higher frequency, more attenuation rate ...

研究了频率对井下电磁波传输特性的影响，采用金属波导法分析了圆形、拱形及弯曲隧道中电磁波的传输特性并给出衰减率近似公式，得出主要结论：在圆形和拱形隧道中，频率越高，衰减率越小，越有利于电磁波的传播；在弯曲隧道中，频率越高，衰减率越大，不利于电磁波的传播；通过特性曲线与井下实验数据相比较得出在900MHz左右为井下无线通信系统传输信号最佳频段。

Article 144 The Government of the Hong Kong Special Administrative Region shall maintain the policy previously practised in Hong Kong in respect of subventions for non-governmental organizations in fields such as education, medicine and health, culture, art, recreation, sports, social welfare and social

第一百四十四条香港特别行政区政府保持原在香港实行的对教育、医疗卫生、文化、艺术、康乐、体育、社会福利、社会工作等方面的民间团体机构的资助政策。原在香港各资助机构任职的人员均可根据原有制度继续受聘。

Small wonder, then, that the Chinese spend more in the shop than any other group of foreign visitors do .

这样的小惊喜，使中国顾客比任何国家的人消费得更多。