单光子探测器量子效率的绝对自身标定方法

提出一种单光子探测器量子效率的绝对自身标定方案，利用光参量下转换过程中产生的光子对在时间上的相关性，先将参量光束分为两路，然后引入相对延时，使同时产生的孪生光子先后进入单光子探测器，然后将探测器之后的电路分为三路，其中一路直接进入计数器得到探测器所探测到的光子的总计数率，另两路用电路方法引入和光路相当的相对延时，经符合电路后进入计数器，得到前后到达探测器的光子对之间的符合计数率.这样，从符合计数率与总光子计数率之比即可在不需要任何其他探测器或者参照标准的情况下获得探测器的量子效率.文中给出两种方案，分别适     

四路激光跟踪测量系统最佳测量区域和系统自标定

研究了系统最佳布局下的最佳测量区域问题,给出了几何精度衰减因子PDOP在三维空间内的变化规律。通过计算机仿真研究了最佳测量布局对系统自标定的影响规律,指出最佳测量布局中的标称配置对系统自标定精度的影响最小,同时这种布局有着最小的几何精度衰减因子。     

A Water-Stable Lanthanide Coordination Polymer as Multicenter Platform for Ratiometric Luminescent Sensing Antibiotics

As a hot topic of global concern, the distinguishing and detecting of antibiotic pollution is crucial owing to its adverse effect on ecosystems and human health stemming from excessive use and poor management. Herein, a water-stable lanthanide coordination polymer sensor (Dy-TCPB) with multiple emitting centers is prepared. The versatile Dy-TCPB can conveniently differentiate various antibiotics, and displays a self-calibration luminescent response to nitrofurazone (NFZ) and furazolidone (FZD). Each antibiotic exhibits notable correlation to a unique combination of the two ligand-to-Dy ion emission intensity ratios, enabling two-dimensional fingerprint recognition. Furthermore, the novel self-calibration sensor demonstrates effective recognition of NFZ and FZD with excellent sensitivity and selectivity, and detection limits as low as 0.0476 and 0.0482 μm for NFZ and FZD, respectively. The synthetic approach for the fabrication of a singular coordination polymer exhibiting multiple emissions provides a promising strategy for the development of facile and effective ratiometric sensors.     

彩虹自标定方法对混合喷雾比例的原位测量

传统彩虹测量技术标定复杂、精度可重复性差且难以适应密闭空间。一种基于多彩虹谱线自标定方法,可省去原有的标定系统装置,将标定过程内化于对彩虹信号的处理,以水为例的测量偏差仅为0.13%。将该技术应用于混合喷雾液滴组分浓度测量中,探究并优化了参与混合的两种液体组分的方案。实验采用60%乙醇-水混合喷雾,原位测量了混合喷雾场多点组分浓度,测量结果差别可以控制在0.5%以内,表明该方法技术在相关领域的应用潜力。     

无线传感器网络RSSI自校正定位

无线传感器网络的许多应用都和节点的位置紧密相关,节点自定位成为当前研究的一个热点。针对信号强度受环境影响较大,提出了接收信号强度自校正定位算法。该算法利用信标节点实际测量信号确定无线信号传播损耗模型,采用组合3边测量获得节点坐标估计值集合,再用加权质心方法确定节点的最终坐标。仿真结果表明,该算法较传统的基于接收信号强度定位方法定位精度有了明显的改进。     

A Self-Calibrated Pipeline ADC with 200 MHz IF-Sampling Frontend

A 13-bit, 50-MS/s pipeline ADC with IF-sampling capability is presented. A high sampling linearity is obtained through the use of bootstrapped switches. A digital self-calibration algorithm with modified capacitor measurement scheme is employed to improve the accuracy of the first two pipeline stages. The prototype, implemented with a 0.35-m BiCMOS (SiGe) technology, shows a 76.5-dB SFDR at a 194.2-MHz signal frequency and dissipates 715 mW power from a 2.9-V supply.     

摄像机标定方法综述

首先介绍了摄像机标定的基本原理以及对摄像机标定方法的分类。通过对最优化标定法、双平面标定法、两步法等传统摄像机方法的具体分析，给出了各种方法的优劣对比；同时对多种自标定方法的研究现状、发展情况以及存在问题进行了探讨。最后给出了发展传统摄像机标定方向、提高摄像机自标定精度的二些参考建议。     

A Fractional-N CMOS DPLL with Self-Calibration

A digital phase-locked loop (DPLL) based on a new digital phase-frequency detector is presented.The self-calibration technique is employed to acquire wide lock range,low jitter,and fast acquisition.The DPLL works from 60 to 600MHz at a supply voltage of 1.8V.It also features a fractional-N synthesizer with digital 2nd-order sigma-delta noise shaping,which can achieve a short lock time,a high frequency resolution,and an improved phase-noise spectrum.The DPLL has been implemented in SMIC 0.18μm 1.8V 1P6M CMOS technology.The peak-to-peak jitter is less than 0.8% of the output clock period and the lock time is less than 150 times of the reference clock period after the pre-divider.     

基于激光多边法的坐标测量系统布局优化

基于激光多边法的坐标测量系统可实现无目标点自标定,其测量精度受到自标定精度的影响。而系统的布局方式是自标定精度主要影响因素之一。通过对无目标点自标定模型误差传递规律的理论分析,对系统的布局方式进行优化,优化结果为直角三棱锥布局。仿真结果表明,直角三棱锥布局提高了自标定精度,从而保证了系统的测量精度。     

一种16位高速数模转换器(DAC)的设计与实现

基于Mixed-Signal CMOS工艺,设计了一种采用分段式电流舵结构的高速高精度DAC.电路设计中同时在该DAC的内部电路中采用了一种新的电流校准技术,既保证了DAC电路的高精度,又减小了梯度误差的影响.电路流片后的实际测试结果表明,该16位DAC在400MSPS转换速率下仍具有良好的性能.