Wideband Digital Downconverters for Synthetic Instrumentation

In this paper, we introduce a new wideband digital downconverter (WDDC) for synthetic instruments (SIs). DDCs first tune to a signal's center frequency using a numerically controlled oscillator and mixer and then zoom-in to the bandwidth of interest using sample rate conversion (SRC). The SRC is required to produce continuously variable output sample rates from a fixed input sample rate over a large range. Current implementations accomplish this using a prefilter, an arbitrary factor resampler, and integer decimation filters. In this paper, we simplify the SRC of the WDDC, yielding a reduction in computational cost by a factor of 3 or more.     

A Low-Cost Binary Division Circuit for Digital Instrumentation

A simple low-cost "latched" division network is described which is capable of executing the "division by time" operation commonly required in many digital instrumentation applications. Typical of these are velocity and acceleration measurements. The division network which was implemented and is described here is capable of performing division with two 16-b numbers (1 b being the sign bit) and producing a 15-b answer within 4.0 ?s (worst case delay). It uses a modified version of the restoring division technique and assumes positive numbers as input, although the modification to operate with negative numbers is possible. A comparison of this technique is made with a previously published design used in a tachometer. Results indicate that significant improvement is possible in both speed and hardware.     

关于爆破震动速度和加速度等效性问题的讨论

本文提出了爆破震动效应的速度和加速度安全控制标准间的等效性原则 ;并对爆破震动速度与加速度实测数据间的互推问题进行了讨论。     

Digital Instrumentation of Slowly Moving Arcs

The slowly moving arc has been instrumented for position and velocity. A practical arc model has been used that has particular application to the needs of industry. Analog circuitry has been developed that interfaces the arc plant with a digital computer. A computer strategy has been applied for time-average filtering without losing the resolution capability of the computer's A/D converter. Through digital differentiation, arc velocity signals are obtained of a quality adequate for industrial control. The entire system is oriented towards the low-priced computer increasingly available in industry. Appendix I contains the flow chart for implementing this instrumentation on a computer. Appendix II presents a simple mathematical model of the instrumentation system.     

一种新型角加速度传感器的数学模型

本文提出了一种全新构思的角加速度传感器,给出了振动摆上所受的力矩曲线,并用理论计算的方法给出了两种数学模型。     

一种新型智能单向加速度、速度、距离传感器

本文对智能单向加速度、速度、距离传感器的工作原理、结构进行了分析和讨论,并对研制过程中的关键技术及解决方法进行了探讨。该传感器是利用压阻效应将加速度信号转换成电信号,再对此信号进行两次积分处理,得到速度、距离的电信号,通过A／D转换进入CPU。该传感器具有智能化、低功耗、多参数同时测量等特点。     

Some Design Considerations for Digital Position and Velocity Detecting Systems

Design-type information is presented for a system that uses pattern recognition principles to sense position and velocity of moving objects. Judging from the literature, little or no work has been done on this type of system. It is believed that these systems have potential industrial and military applications, e.g., an optical object finder that identifies objects in addition to locating them, or a process control sensor to detect grain size and other dimensional properties. One of the most important parts of the system is the receptor. Minimum receptor matrix size as a function of pattern shapes, orientation, position, and velocity is considered and results are presented.     

爆破振动速度与加速度的等效换算研究

针对建筑结构抗震设计采用爆破振动加速度、工程爆破安全控制标准采用振动速度的不一致问题,通过理论分析和现场测试试验对爆破振动速度峰值和加速度峰值的等效换算及影响因素进行了分析。研究表明:爆破振动速度峰值和加速度峰值可通过公式进行等效换算,换算系数与最大单段药量、爆心距、起爆方式等影响因素相关。     

Group Velocity Dispersion of Ring Cavities with Lateral and Angular Dispersive Elements

Abstract

A general formalism for the calculation of group velocity dispersion of laser cavities containing elements with angular or lateral dispersion is developed. This formalism is applied to the cavity of a ring laser with one prism and to a cavity with two antiparallel prisms. The calculated results are in agreement with experimental findings for such lasers.     

基于栅结构谐振器的X和Y轴加速度及Z轴角速度的组合测量

本文利用一由两个相互垂直的加速度计组成的栅结构谐振器来同时测量z轴和Y轴的加速度以及z轴的输入角速度．此谐振器利用变面积电容进行检测,具有良好的线性度及快速的信号响应．此谐振器的x轴及Y轴的加速度计的谐振频率分别为1．9315kHz和1．8403kHz．在初始状态下,Ⅳ轴的加速度计被驱动进入谐振状态,且Y轴的加速度随着x轴的加速度计一起振动．当=轴存在角速度输入时,Y轴的加速度计会相应地沿Y轴进行振动,而x轴及Y轴的加速度会改变相应轴上加速度计的平衡位置．测试结果表明,此器件的z轴角速度灵敏度为16mV／（（9）·s-1）,x和Y轴的加速度灵敏度分别为49mV／g和244mV／g．z轴角速度输出的噪声等效角速度为0．0138（s·／Hz-1）,x和Y轴加速度输出的噪声等效加速度为0．42X10-3g／／Hz和0．074X10-3。g／√Hz．     

Digital Instrumentation for the Time Integral of the Square of a Slowly Fluctuating Voltage

A portable digital instrument is described that provides a decimal readout of 1) the time integral of the square of a fluctuating voltage and of the measuring time on two decimal displays, and 2) the amplitude distribution of the voltage. The instrument has no low-frequency limitations. For periodic inputs, measurement may take place over one cycle. For either periodic or random inputs, measurement may be made to commence on a start signal and run for a programmed time. Readout is available immediately at the end of the measuring time, so that the instrument can be used in on-line real-time process control. The voltage under measurement is sampled systematically, and the sampled data are processed using a unique special-purpose digital computer. The paper describes the principles on which measurements are based, and the design and error characteristics of an instrument in which, for most waveforms (e. g., sine, ramp, white noise), the maximum error is in the region of 1 percent and the upper frequency limit is about 1 kHz.     

基于数字图像处理的破片速度参数测量

介绍了两种常用的测量破片速度参数的方法,研究了数字图像处理技术在终点效应研究中的实现方法,合理设计试验并利用数字图像处理技术测量了破片的速度参数,具有一定的可行性,实用性强,研究结果表明,利用此方法所得到的破片速度参数与理论计算以及其它方法所测得的结果基本吻合。     

粘滞阻尼和干摩擦对物品包装跌落冲击的最大加速度的影响

考虑了在跌落冲击时粘带阻尼和干摩擦两种阻力同时存在对物品加速度的影响,导出了包装件受冲击作用时产品的最大响应加速度,并对之进行了讨论。     

Instrumentation for chemical cytometry

Capillary electrophoresis is ideally suited to chemical analysis of individual cells. Small mammalian somatic cells (approximately 15 microns in diameter) can be analyzed by injecting the intact cell into a capillary, lysing the cell, separating and detecting the cellular components, and reconditioning the capillary prior to the next injection. In this paper, we report on technical improvements to single-cell analysis. We designed an inexpensive multipurpose single-cell injector that facilitates the following: (i) monitoring of injection, (ii) reproducible pressure- or electrokinetic-driven injection of the cell, (iii) complete cell lysis by SDS within 30 s of injection, and (iv) pressure-driven capillary reconditioning. Furthermore, we report on the analysis of glycosylation and glycolysis in single human carcinoma cells (HT29 cell line). The reliability and quality of the analysis is confirmed by comparing electropherograms from single cells and those from purified cell extracts.     

Research on Angular Output Velocity of a Drive Shaft with Double Cross Universal Joints

The study object is the angular output velocity of the drive shaft which is made up of two series-wound cross universal joints.We have deduced the function relation between the angular output velocity and initiative input angle of the drive shaft with double cross universal joints that is based on the calculation formula of the angular output velocity of a single cross universal joint,and by analyzing the relation between the two input angles.By using this function relation,the constant velocity condition o...     

Instrumentation for fringe multiplication

The paper describes commercial fringe multiplication equipment designed for rapid analysis of frozen stress slices.     

高速动能弹侵彻硬目标加速度测试技术研究

通过理论分析、计算机模拟和现场实测,研究了弹体高速侵彻硬目标时,弹体中应力波传播对弹体实测加速度的影响规律;采用不同密度、不同孔径的泡沫铝材料对电路模块进行保护。利用自主研制的弹载高g值加速度存储测试仪器,现场测取了弹体侵彻混凝土靶过程中的加速度,并分析了测试数据的有效性。     

角谱理论用于衍射光学元件数字仿真

本文采用衍射角谱理论对衍射光学元件的光场分布进行数字计算.该理论包括两种表达方式:既可用含有传递函数的等式表达,也可用含有点扩散函数的等式表达.这两种计算方法在本质上是一致的.然而,在MATLAB计算过程中,它们又具有不同的适用条件,通过分析,将它们分为近场算法和远场算法,并且展示了它们的计算实例.结果表明,在标量衍射理论成立的条件下,不改变衍射元件抽样间隔和抽样点数,利用这两种算法能够快速、准确计算不同位置处的衍射图样.该方法对衍射光学元件像面光场分布的精确计算具有重要的意义.