High-SpeedReal-TimeDataAcquisitionSystem Realized by Interleaving/Multiplexing Technique

The interleaving/multiplexing technique was used to realize a 200?MHz real time data acquisition system. Two 100?MHz ADC modules worked parallelly and every ADC plays out data in ping pang fashion. The design improved the system conversion rata to 200?MHz and reduced the speed of data transporting and storing to 50?MHz. The high speed HDPLD and ECL logic parts were used to control system timing and the memory address. The multi layer print board and the shield were used to decrease interference produced by the high speed circuit. The system timing was designed carefully. The interleaving/multiplexing technique could improve the system conversion rata greatly while reducing the speed of external digital interfaces greatly. The design resolved the difficulties in high speed system effectively. The experiment proved the data acquisition system is stable and accurate.

A 12bit 300MHz Current-Steering CMOS D/A Converter

The proposed DAC consists of a unit current-cell matrix for 8MSBs and a binary-weighted array for 4LSBs,trading-off between the precision,speed,and size of the chip.In order to ensure the linearity of the DAC,a double Centro symmetric current matrix is designed by the Q2 random walk strategy.To achieve better dynamic performance,a latch is added in front of the current switch to change the input signal,such as its optimal cross-point and voltage level.For a 12bit resolution,the converter reaches an update rate of 300MHz.

A 16 bit Stereo Audio ΣΔ A/D Converter

A 16 bit stereo audio novel stability fifth-order ∑△ A/D converter that consists of switched capacitor ∑△ modulators, a decimation filter, and a bandgap circuit is proposed. A method for the stabilization of a high order single stage ∑△ modulator is also proposed. A new multistage comb filter is used for the front end decimation filter. The ∑△ A/D converter achieves a peak SNR of 96dB and a dynamic range of 96dB. The ADC was implemented in 0. 5μm 5V CMOS technology. The chip die area occupies only 4. 1mm × 2.4mm and dissipates 90mW.

基于D-分割法的直流变换器遗传自抗扰控制器设计

针对光伏发电系统中DC-DC变换器由于负载和工作环境条件变化等扰动引起的输出波动问题,提出一种基于D-分割法的直流变换器遗传自抗扰控制器(ADRC)设计方法。该方法适用于设计光伏发电领域中的双向DC-DC变换器,采用D-分割法获得满足闭环系统鲁棒稳定的ADRC控制器参数范围;利用具有全局寻优能力的遗传算法,按综合性能指标在该范围内进行参数寻优。实验结果表明,所提基于D-分割法的直流变换器遗传自抗扰控制器设计方法能有效抑制微网母线侧的电压波动和负载突变,提高控制器的鲁棒性,增强光伏发电系统的动态响应性能和抗干扰能力。

一种高速A/D转换器时域重构技术研究

A/D转换器在航空航天系统中的重要元器件,随着器件转换时钟频率不断提高而其工作环境不断恶化,如何准确测试其时间参数对于全面评价A/D转换器性能特别重要。目前对于高速A/D转换器时间参数测试,主流方法是通过示波器直接测试其输出,该方法对于示波器采样速度要求比较高。文章提出一种高速A/D转换器时域重构技术,可以通过计算机数字信号处理方法来实现高速A/D转换器时间参数测试,同时避免对示波器采样速度的依赖。同时,在研究高速A/D转换器时域重构技术方法及其应用的基础上,通过了相关试验验证。

S.D. Krashen's Language Acquisition Theory and the Teaching of Business English Reading

This paper first illustrates S.D. Krashen's language acquisition theory, especially two of his five hypotheses as well as the guidance of these theories towards the teaching of business English reading for students majored in business English.

Design and implementation of 1 GHz high speed data acquisition system

With the development of current electronic technology, numerous high-speed data acquisition systems provide a variety of potential benefits. This article describes a high-speed data acquisition system which consists of ECL logic and TTL logic devices, samples and stores data with a 1 GHz clock. This system is accomplished easily and works stably. A performance test of this system has been undertaken and the results show that the effective number of bits （ENOB） is more than 6.5 bits.

Numeric Simulation of Single Passage Ternary Turbulence Model in Hydraulic Torque Converter

Based on the renormalization group theory, a hydraulic torque converter 3 D turbulent single flow passage model is constructed and boundary condition is determined for analyzing the influence of the fluid field characteristic and parameters on the macroscopic model. Numerical simulation of the single fluid path is processed by computational fluid dynamics and the calculated results approach to experimental data well, and especially in low transmission ratio the torque and head results are more close to experimental data than the calculated results of beam theory. This shows that the appropriate ternary analysis method and reasonable assumption of boundary condition may analyze the flow field more precisely and predict the performance of torque converter more accurately.

Data Acquisition System for Electron Energy Loss Coincident Spectrometers

A Data Acquisition System （DAQ） for electron energy loss coincident spectrometers （EELCS） has been developed. The system is composed of a Multiplex Time-Digital Converter （TDC） that measures the flying time of positive and negative ions and a one-dimension positionsensitive detector that records the energy loss of scattering electrons. The experimental data are buffered in a first-in-first-out（FIFO） memory module, then transferred from the FIFO memory to PC by the USB interface. The DAQ system can record the flying time of several ions in one collision, and allows of different data collection modes. The system has been demonstrated at the Electron Energy Loss Coincident Spectrometers at the Laboratory of Atomic and Molecular Physics, USTC. A detail description of the whole system is given and experimental results shown.

A 10bit 2GHz CMOS D/A Converter for High-Speed System Applications

This paper presents a 2GS/s 10bit CMOS digital-to-analog converter （DAC） that consists of two unit current-cell matrixes for 6MSBs and 4LSBs, respectively, trading off between the precision and size of the chip. Current mode logic （CML） is used to ensure high speed,and a double centro-symmetric current matrix is designed by the Q^2 random walk strategy in order to ensure the linearity of the DAC. The DAC occupies 2.2mm × 2.2mm of die area and consumes 790mW with a single 3.3V power supply.

A 128×128 SPAD LiDAR sensor with column-parallel 25 ps resolution TA-ADCs

This paper presents a design of single photon avalanche diode(SPAD)light detection and ranging(LiDAR)sensor with 128×128 pixels and 128 column-parallel time-to-analog-merged-analog-to-digital converts(TA-ADCs).Unlike the conventional TAC-based SPAD LiDAR sensor,in which the TAC and ADC are separately implemented,we propose to merge the TAC and ADC by sharing their capacitors,thus avoiding the analog readout noise of TAC’s output buffer,improving the conversion rate,and reducing chip area.The reverse start-stop logic is employed to reduce the power of the TA-ADC.Fabricated in a 180 nm CMOS process,our prototype sensor exhibits a timing resolution of 25 ps,a DNL of+0.30/−0.77 LSB,an INL of+1.41/−2.20 LSB,and a total power consumption of 190 mW.A flash LiDAR system based on this sensor demonstrates the function of 2D/3D imaging with 128×128 resolution,25 kHz inter-frame rate,and sub-centimeter ranging precision.

Seismic Data Acquisition Techniques on Loess Hills in the Ordos Basin

High-resolution exploration for lithologic targets confronted with difficulties due to the original brought out from geophysical and geologic characteristics of the loess hills and the very thick deserts in Ordos. Scientific research since mid 1990s has conducted three acquisition techniques including the high-resolution crooked line survey in valleys, high-resolution multiple straight line survey and 3D survey, under different surface conditions and for different geological targets.

Performance Optimization of Torque Converters Based on Modified 1D Flow Model

A methodology for performance optimization of torque converters is put forward based on the one-dimensional (1D) flow model. It is found that the inaccuracy of 1D flow model for predicting hydraulic performance at the low speed ratio is mainly caused by the separation phenomenon at the stator cascade which is induced by large flow impinging at the pressure side of the stator blades. A semi-empirical separation model is presented and incorporated to the original 1D flow model. It is illustrated that the improved model is able to predict the circumferential velocity components accurately, which can be applied to performance optimization. Then, the Pareto front is obtained by using the genetic algorithm (GA) in order to inspect the coupled relationship among stalling impeller torque capacity, stalling torque ratio and efficiency. The efficiency is maximized on the premise that a target stalling impeller torque capacity and torque ratio are achieved. Finally, the optimized result is verified by the computational fluid dynamics(CFD) simulation, which indicates that the maximal efficiency is increased by 0.96%.

Numerical simulation of the flow field of a flat torque converter

A flexible flat torque converter was proposed to fulfill the requirement of miniaturization and power density maximization for automobiles.Constructed by two arcs joined by lines,the torus was designed directly from design path.The influence of flatness on the performance of the torque converter was evaluated.The software CFX and standard k-ε model were adopted to simulate the internal flow fields of the torque converter under different flatness ratios.The results indicated that the performance of the torque converter got worse as the flatness declined,but the capacity of pump increased.The efficiency and the torque ratio dropped slightly as the flatness ratio decreased.So the torque converter could be squashed appropriately to get high power density without too much efficiency sacrifice.But when the flatness ratio was below 0.2,there was a significant drop in the efficiency.

Analytical Modelling and Experiment of Novel Rotary Electro-Mechanical Converter with Negative Feedback Mechanism for 2D Valve

The manufacturing of spiral groove structure of two-dimensional valve(2D valve)feedback mechanism has shortcomings of both high cost and time-consuming.This paper presents a novel configuration of rotary electro-mechanical converter with negative feedback mechanism(REMC-NFM)in order to replace the feedback mechanism of spiral groove and thus reduce cost of valve manufacturing.In order to rapidly and quantitative evaluate the driving and feedback performance of the REMC-NFM,an analytical model taking leakage flux,edge effect and permeability nonlinearity into account is formulated based on the equivalent magnetic circuit approach.Then the model is properly simplified in order to obtain the optimal pitch angle.FEM simulation is used to study the influence of crucial parameters on the performance of REMC-NFM.A prototype of REMC-NFM is designed and machined,and an exclusive experimental platform is built.The torque-angle characteristics,torque-displacement characteristics,and magnetic flux density in the working air gap with different excitation currents are measured.The experimental results are in good agreement with the analytical and FEM simulated results,which verifies the correctness of the analytical model.For torque-angle characteristics,the overall torque increases with both current and rotation angle,which reaches about 0.48 N·m with 1.5 A and 1.5°.While for torque-displacement characteristics,the overall torque increases with current yet decrease with armature displacement due to the negative feedback mechanism,which is about 0.16 N·m with 1.5 A and 0.8 mm.Besides,experimental results of conventional torque motor are compared with counterparts of REMC-NFM in order to validate the simplified model.The research indicates that the REMC-NFM can be potentially used as the electro-mechanical converter for 2D valves in civil servo areas.

一种14位80 MS/s流水线型A/D转换器设计

基于SMIC 0.18μm CMOS工艺,设计了一种14位80 MS/s的流水线型A/D转换器(ADC)。为了降低ADC整体功耗,首级电路采用2.5 bit无采样保持(SHA-less)结构。进一步,基于套筒式共源-共栅结构提出了一种改进型运放,通过复制尾电流反馈技术和增益提高技术的应用提升了运放的速度和增益,且功耗较低。比较器仅采用动态锁存器以减小级间延迟。还采用了栅压自举开关降低开关导通电阻,提高采样网络带宽和线性度。芯片测试结果表明,在1.8 V电源电压、采样频率为80 MHz的条件下,输入信号频率分别为10 MHz和70 MHz时,ADC的动态参数性能相差不大。其中,输入信号频率为70 MHz时,信噪失真比(SNDR)为72.2 dB,无杂散动态范围(SFDR)为85.82 dB,有效位数(ENOB)为11.7 bit,品质因数(FoM)为0.38 pJ/(conv·step)。

血清GSDMD、ACE2在小儿川崎病中的表达水平及临床意义研究

目的 探索血清焦孔素蛋白D(GSDMD)、血管紧张素转化酶2(ACE2)在小儿川崎病(KD)患儿中的表达水平及临床意义。方法 收集2020年1月至2022年1月该院诊治的90例KD患儿为KD组,根据KD患儿是否发生冠状动脉损伤(CAL),将KD组分为CAL组(32例)和非CAL组(58例),选取同期因急性呼吸道感染发热住该院的患儿50例为发热对照组,另选取同期该院儿外科行择期手术的腹股沟斜疝患儿50例为对照组。采用酶联免疫吸附试验检测血清GSDMD、ACE2水平。Pearson相关分析血清GSDMD、ACE2与临床指标的相关性。多因素Logisitic回归分析KD患者发生CAL的影响因素。受试者工作特征(ROC)曲线分析血清GSDMD、ACE2对KD患儿发生CAL的诊断价值。结果 KD组血清GSDMD、ACE2水平高于发热对照组和对照组,差异有统计学意义(均P<0.05)。相比于非CAL组,CAL组KD患儿发热持续时间、丙种球蛋白治疗时间、红细胞沉降率、血小板计数、C反应蛋白、GSDMD、ACE2水平均明显较高,而血钠、白蛋白明显较低,差异有统计学意义(均P<0.05)。Pearson相关分析结果,KD组患儿血清GSDMD、ACE2水平与发热持续时间、丙种球蛋白治疗时间、红细胞沉降率、血小板计数、C反应蛋白呈正相关(均P<0.05),与血钠、白蛋白呈负相关(均P<0.05)。多因素Logistic回归分析结果显示,血清GSDMD、ACE2升高是影响KD患儿发生CAL的独立危险因素。ROC曲线分析结果显示,血清GSDMD、ACE2两项联合检测KD患儿发生CAL的曲线下面积(AUC)及其95%CI为0.918(0.868~0.949),明显大于血清GSDMD、ACE2单项检测的AUC及其95%CI[依次为0.838(0.789~0.887)、0.865(0.811~0.912)],差异有统计学意义(Z=5.116、4.217,均P<0.05)。结论 血清GSDMD、ACE2两项联合检测对于KD患儿发生CAL具有较高的诊断价值。

针对高转速A/D采集的自适应平滑处理方法

船舶领域常用瞬间转速测量对各类大型机械设备进行运行状态监测及信号控制,为了提高瞬时转速测量的精度,从而提高船舶设备运行控制的准确性以及设备健康状态评估的有效性,基于传统模数转换(A/D)采集的采集转速方法——测频率法和测周期法,通过对A/D转速测量点数进行多周期平滑处理,并加入转速分段测量的自适应机制,提高A/D采集瞬时高转速的精度。在进行模拟仿真与理论结果比较验证后,进一步开展在实际测量中自适应平滑处理方法对转速测量精度影响的研究。仿真及试验结果表明,采用的转速测量方法针对不同的转频均可有效降低转速测量误差,研究成果可为船舶机械设备转速测量提供一定参考。

Development of Data Acquisition Card Driver for ICRH System on EAST

Presented in this paper is the development of the driver for the data acquisition card with a peripheral component interconnection （PCI） local bus on the ion cyclotron range of frequency heating （1CRH） system. The driver is mainly aimed at the embedded VxWorks system （real-time operating system） which is widely used in various fields of real-time systems. An efficient way is employed to develop this driver, which will advance the real-time control of the ICRH system on the experimental advanced superconductor tokamak （EAST）. The driver is designed using the TORNADO integrated development environment （IDE）, and implemented in C plus language. The details include the hardware configuration, analogue/digital （A/D） and digital/analogue （D/A） conversion, input and output （I/O） operation of the driver to support over five cards. The data acquisition card can be manipulated in a low-level program and meet the requirements of A/D conversion and D/A outputs.

Optimization on the High Precision 3D Seismic Acquisition Parameters in Leijia Tight Sandstone Oil Area

The main targets of seismic exploration research in Leijia carbonatite tight sandstone oil area of Liaohe depression are thin reservoirs prediction and minor faults identification, which is one of the important representatives of complex exploration objects in Liaohe depression. High precision 3D seismic exploration has significantly improved the ability of thin reservoirs prediction and minor faults identification of this area. Reducing the cost of high precision 3D seismic exploration through optimizing the acquisition parameters is very important for the next step exploration and development of Liaohe depression and similar areas. Based on high precision 3D seismic acquisition data in Leijia tight sandstone oil area, multiple sub-geometries are obtained with different bin sizes, different folds, different aspect ratio, different line intervals by extracting receiver points and shot points, and PSTM processing is performed respectively, obtained PSTM datasets of the sub-geometries, extract time slices, amplitude slices along the layer, coherent slices and so on. We evaluate the data results of the sub-geometries from the aspects of signal-to-noise ratio, thin reservoirs resolution, acquisition footprint and so on. Considering the exploration cost and data effect of each sub-geometry, the optimal direction of the main parameters of high precision seismic exploration in Liaohe depression is put forward, and the acquisition effect of adjacent area by the optimized parameters is given.