模数的

Equipped with AT89C51,the temperature sensor and the modulus convertor and coordinated by soft and hard wares,the system can fufil the instantaneous gathering of multichannel temperature signal,then,by meaus of asynchronous string communication,send the digital signal to PC which can separately display the instantaneous value and the average value of each channel temperature in bar diagram and weblike form,and print the temperature curve graph through data scale transferring,analyzing,and collating.

该系统运用单片机AT89C51、温度传感器保温器及模数转换器，通过软硬件的配合，实现了多路温度信号的实时采集，用异步串行通信发送数字信号到PC机，PC机经过数据的标度转换、分析、整理，分别用棒状图和网状表格显示各路温度瞬时值和平均值，打印出静态降温调温曲线图。

The laser unit, because of its monochromaticity and small divergency, is used as sensor's light source. Devices and chips provided with high-speed responsing and processing capabilities are employed.

该方案采用光电传感、模数转换的方法，通过信号处理把被摄对象的高速时空信息以最简单最直观的方式展现出来。

In the data acquisition system, CD4051 and AD574- the A/D transform, are used as hard core to receive the signal from the infra-red ray temperature sensor; the data acquisition depend on CPU; in the keyboard/ display system, a 74LS48 as the driver to drive LED works; in the warning circuit, I used two color LED and a buzzer as one unit to work; DAC0832 converter is the center of the D/A transform; execution unit, I used DDZIII type electromotive unit; the auto-man, it is a disabling of the other control circuit, this can secure production all the time.

在数据采集部分，以多路开关CD4051和AD574模/数转换器为核心接收来自红外线传感器的信号；数据处理依赖CPU；键盘/显示部分，以74LS48驱动LED数码管工作；报警单元，采用了双色LED加蜂鸣器的组合；D/A转换采用了DAC0832转换器；执行器采用DDZIII型电动执行器；手/自动切换装置则屏蔽了之前的电器部分，安全可靠。

The study inchcates that the best error pulse width and the competition pulse width are proportional to the sampling period to us and the modulation degree of SPWM; the number of competition pulse are dependent on the slop of us.

均与模数转换的采样周期和调制深度成正比，与载波比成反比；竞争脉冲的个数由us的斜率决定。

Digital circuit implementation possibly induces pseudomorph because of the data conversion precision.

由于数字时滞电路存在模数转换精度的问题，所以采用数字时滞电路的时滞反馈Lorenz系统容易产生不真实的电路现象。

Sample and hold circuit is an indispensable important circuit block, which almost determines the performance of the whole A/D converter.

采样保持电路作为模数转换器的必不可少的关键单元，很大程度上决定了ADC的性能。

Form the result of this study, it is found that the threshold shearing strain increases with admixed od cement.

现地土壤和水泥改良土的动态剪力模数随著剪应变的增加而减少，阻尼比随著剪应变的增加而增加。

It explains abstraitively the working principle of A/D converter of full-parallel, seriesparallel and successive approximation type.

本文简介了瞬态记录仪的产生及发展，并介绍了它的核心部件模数转换器在瞬态记录仪中的应用。

Nonuniform sampling can acquire signal of which the frequency exceeds the threshold in Nyquist theorem when the sample rate of analogue-to-digital device is lower than usual.

非均匀采样可以在对模数转化器件的采样频率要求较低的情况下，提取超出Nyquist采样定理限制的频率。

This paper in vestigates the history of China's machine design methods 'it discussed machine design ideas in ancient China.① The system idea in machine design.②The idea of machine design.③The idea of standardization in machine design.④The idea of automa...

以此为题，探讨了中国古代机械设计思想的科学成就：其一，机械设计中的系统思想；其二，模数设计思想；其三，机械设计中的自动思想；其四，机械设计中标准思想。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。