采样单元

Make the use of AD7730 and dsPIC30f6010A to compose the sampling and arithmetic unit of the electron belt weigher.

利用 AD7730和 dsPIC30f6010A 构成电子皮带称的采样和运算单元。

Error analysis of digital instruments on their characteristic parts including sample/holder circuit error and analogue/digital convector error was reviewed in this paper. With the help of some examples and data tables, error origins and the synthetic method were discussed.

评价了数显仪特征部分误差分析方法，包括：采样／保持电路、模数转换单元的误差，并通过典型例子和列表数据分析了多种误差源及其综合计算方法。

This high voltage electrostatic precipitation controller has 7 channels of analog input,2 channels of analog output, 12 digital inputs and 16 digital outputs. The analog input includes primary current, secondary current, primary voltage, secondary voltage, etc. Controller uses MAX 187 as the A/D converter, which ensure the sampling speed and the conversion precision in the same time. The processor unit is RCM2250 module. Rabit 2000 processor, a 128K SRAM and a 256K Flash Rom are integrated in RCM2250, which improves the performance of pricipitation controller. MAX504 is used to produce the 4~20mA current output.

模拟量输入采集的信号有升压变压器一次电流、一次电压、二次电流、二次电压等，采用12位逐次比较式A/D转换器MAX187，兼顾采样速率和转换精度；中央处理单元采用以8位嵌入式处理器Rabbit2000为基础的RCM2250模块，外扩128KSRAM和256K Flash ROM，内部资源丰富，提高了控制器的整体性能；模拟量输出采用内带基准源的10位电压输出数模转换器MAX504，实现了标准4～20mA电流信号输出；控制器通过控制算法在相应开关量点上输出可控硅的触发脉冲。

The optimal density of sampling points can be determined by the sampling grid cell size and the field area.

合理的采样密度可以根据允许的采样误差及要求的属性地图输出栅格单元尺寸而定。

We choose the TMS320VC5402, digital signal processor, as the computing unit, filtering the sampled signal, truncating the harmonic whose frequence greater than 2500hz, then we use the window-interpolation FFT algorithm to get the refined frequence, amplitude, phase of harmonic in sampled voltage and current, other parameter such as harmonic ratio, active power, reactive power, power factor, three-phase unbalance can be also computed base one the result of window-interpolation FFT.

选用TMS320VC5402高速数字信号处理器作为运算单元，先对采样信号进行数字滤波，去除50次以上谐波分量，然后应用加窗双峰插值FFT算法计算电压电流的各次谐波频率、幅值和相位，以及谐波含有率、有功功率、无功功率、三相不平衡度等各项电能指标，同时利用锁相环电路硬件跟踪电网频率以减小采样失步度。

The analysis of the samples collected from the wastewater treatment plant showed that the recycled supernatant had a pH of 7.16~8.21, a conductivity of 371.1~769.1 μmho/cm, a total dissolved solid of 193.3~399.9 mg/L, and a turbidity of 0.901~54.3 NTU. The suspended solids of the recycled supernatant was found to be 0.4~45.6 mg/L, lower than the standard value in the Effluent Standards (50 mg/L). The ammonia nitrogen (NH3-N) and the Total Organic Carbon of the recycled supernatant were found to be 0.06~1.5 mg/L and 1.533~17.437 mg/L, respectively. The analysis of the Chemical Oxygen Demand of the wastewater treatment plant showed a concentration of 12.1~128.5 mg/L in the sample of the recycled supernatant.

在废水处理单元采样分析结果方面，回收之上澄液之pH范围为7.168.21间、导电度值范围在371.1769.1 μmho/cm间、总溶解固体量范围在193.3399.9 mg/L间、浊度范围则在0.90154.3 NTU间；在悬浮固体方面，其回收上澄液之范围在0.445.6 mg/L间，且回收水之悬浮固体均小於放流水水质法规标准值50 mg/L；在氨氮（NH3-N）方面，回收上澄液之范围在0.061.5 mg/L间；在总有机碳部份，回收上澄液之浓度范围在1.53317.437 mg/L间；而在净水场废水处理单元化学需氧量分析结果上，可发现净水场在回收上澄液之样本部份其浓度在12.1128.5 mg/L间。

First designed to ensure that the access of the timing there is no problem with convergence, The control unit can be controlled signal is the work of the functional unit of sampling, Second, we must ensure that the results of the implementation of directive is correct.

首先要保证所设计的通路在时序衔接上没有问题，控制单元发出的控制信号能够被正在工作的各功能单元采样到，其次要保证指令的执行结果是正确的。

The crosstalk reducing unit (14) has a sample rate converter (19) coupled to a synchronous clock for converting the output of the subtractor to the data signal (8) at a synchronous sample rate.

所述串扰降低单元(14)具有与同步时钟耦合的采样率转换器(19)，用于以同步采样率把所述减法器的输出转换为数据信号(8)。

The simulation of the bandgap reference using ideal resistents shows that It's precision is 16.6 ppm.The dynamic range of the sensor is increased by 2~N using multi-sample. The FPN is cancelled using CDS. The pipeline ADC has the good tradeoffs of resolution, sample rate and area.

像素阵列的扫描方式使用多采样技术可以提高传感器动态范围2~N倍，相关二次采样技术消除了像素单元之间的固定模式噪声，使用流水线式的模数转换器可以实现好的分辨率、速度和面积等的折衷。

To solve the exsisting problems in the realization of the LFM/CW radar, the thesis presents a technique for dynamically measuring the LFM/CW signals, which can accomplish the dynamic measurements of FM linearity, FM bandwidth and FM slop of the transmitted signals of LFM/CW radars. This technique creates an effective and accurate means of judging the performance of LFMCW radars. The linearity-correction techniques presented in the thesis successfully make the linearity of the transmitted signals of an actual LFM/CW radar reduce from approximately 25% to 0. 1%(or r. m. s linearity of 0.04%), better than the best results (0.22%) obtained by foreign researchers with complex linearization closed-loop in the same kind of LFM/CW radars, according to the published literatures during the last decade. In order to improve the capability of the real-time processing and range-cells management of LFM/CW radars, the principle of equivalent mixing by lacking-sampling process of band-pass real signals is proposed based on the well-proved improvedversion of sampling theorem of band-pass real signals. This principle is used to configure the range-segments processing of the beat signals of an actual LFM/CW radar. The techniques of system-background interference suppression and the beat signal's dynamic range suppression are proposed, and are realized in an actual LFM/CW radar to demonstrate their effectiveness.

针对线性调频连续波雷达实现中急待解决的技术问题，文中提出并验证了线性调频连续波信号的综合动态测试技术，可以完成对线性调频连续波雷达发射信号的扫频线性度、扫频带宽和扫频斜率的综合动态测试，为衡量实际线性调频连续波雷达的系统性能创立了精确有效的测试手段；文中建立的非实时闭环动态校正技术使一部实际的线性调频连续波雷达的发射信号（时带积3×10〓）的扫频线性度从25%改善为0.1%（方均根线性度0.04%），优于国外已公布的80年代同类雷达中采用复杂的实时闭环动态校正环路所获得的实际结果（0.22%）；为了改善线性调频连续波雷达的实时性和分辨单元数处理能力，文中发展完善了实带通信号的采样定理并给予了严格证明，并在此基础上提出了欠采样等效混频原理，将其应用于实际线性调频连续波雷达的距离分段处理中；针对线性调频连续波雷达中系统背景干扰和回波动态范围问题，创立了系统背景综合抑制技术和频域动态范围压缩技术，并将它应用于实孔线性调频连续波雷达系统中，显示出它们的有效性。

By the time of its fall, most of the prisoners were writers who had written against the corruptions of the government.

到它被攻陷的时候，里面多数的犯人是写了反对政府贪污文章的作家。

The most obvious variation to ovum morphological character was that the color was changed from light green to sepiaceous in embryonic development, and all the ovums were almost hatched after 96h.

在胚胎发育过程中卵的形态特征最明显的变化是颜色从淡绿到深褐色，卵在发育96h后卵基本全部孵化。