A Quick Color Test to Detect Lead Release From Glazed Ceramic and Enameled Metalware

Abstract

A color test is presented for the purpose of quickly identifying glazed ceramic and/or enameled metalware which releases excessive Pb. Citric acid solution on filter paper is used to extract Pb from the ware and a Pb-sensitive chromogen indicates the presence of Pb on the paper. The quick color test takes approximately 30 min and is useful for screening ware to determine the need for testing by the 24-h method of the Association of Official Analytical Chemists/American Society for Testing and Materials.     

Design,simulation, and implementation of an integrated,hybrid photocurrent-to-digital converter in CMOS technology

This article presents a design, modeling, simulation, and measurements of a hybrid photocurrent-to-digital converter integrated together with photo-diodes in a 130 nm CMOS process, without any additional process steps. Photo-currents of integrated photo-diodes with different responsivities to different wavelength of the light and light intensity are converted into 22-bits digital results in 2 ms. The results can then be converted into CIE XYZ or RGB color luminosity space using dedicated DSP algorithm. A high resolution, hybrid, ADC converts light induced photo-currents into 22-bit digital results, canceling the dark current of the photodiodes and 1/f noise and offset voltage of the input stage of the modulator. The whole converter consumes on average less than current at supply voltage at 10 conversions per second. It occupies approx. 0.8 mm² of silicon area, including the three photodiodes, a multiplexer, and the ΣΔ modulator.     

不同调光方式LED照射下的人体非视觉效应

分别采用模拟调光和PWM调光方式实现LED光调节。采用生理参数法,以在校大学生为研究对象,选择3种色温(3 000,5 600,6 500 K)LED光源,在3种照度(300,500,800 lx)水平下,对8名(5男,3女)受测者在实验前后的脉搏和瞳孔进行测量。选择同样3种色温LED光源,分别采用两种调光方式添加蓝光(464nm,20 lx)实现300 lx的照明环境,对12名(8男,4女)受测者在实验前后的脉搏和瞳孔进行测量。结果表明:两种调光方式实现的LED光环境对人体脉搏变化率和瞳孔收缩率的影响均没有显著性差异;在测试照明环境中添加蓝光,可引起人体脉搏变化率和瞳孔收缩率增大,峰值处分别增加约6%和9%。     

Flux and fluence dependence of disorder produced during implantation of 11B in silicon

The flux and fluence dependence of disorder produced in silicon during the implantation of ¹¹B has been investigated at room temperature, -50°C. and -120°C. Implantations were carried out with 200 keV ¹¹B ions using current densities in the range from 0.06μA/cm² to 15μA/cm², and the disorder monitored by measuring the energy spectra of backscattered protons which were incident on the sample at 450 keV parallel to a (110) axis. Significant differences in the dependence of the disorder on ¹¹B flux and fluence were observed between the implantations performed at room temperature and those carried out at the two lower temperatures.     

Color centers in irradiated MgF2

Abstract

Color centers in rutile-structured MgF₂ single crystals irradiated at 20K/360K by reactor neutrons are investigated spectroscopically at LNT. Four different types of the F-F vacancy bond in MgF₂ are possibly identified to the observed absorption bands as due to the F₂ centers; instead of previous assignments, the 300nm band to the F₂(D_2h), the 325nm band to the F₂(C₁), the 355nm band to the F₂(C_2v), and the 400nm band to the F₂(C_2h) centers.     

多摄像机在无重叠区域的目标匹配算法

基于颜色特征的目标匹配方法具有很好的区分性和直观性,但是特征本身受光线变化、背景复杂度等影响而对于目标识别准确率存在差异.针对这一现状,提出了一种新的基于时空局部特征和颜色特征的目标匹配方法.利用时空局部特征3-D LSK对待测视频中的运动目标进行行为识别,识别出具有相同行为目标.再结合目标的颜色特征,通过基于区域权重(Weighted Region Matching)的颜色匹配方法来识别出具有相同颜色的目标.对无重叠区域的多个测试视频进行的相关实验表明,该算法能够有效识别出普通场景下的不同目标,对于衣着颜色相近的不同目标也有很高的识别率.     

互联网网络时延特征研究

互联网宏观拓扑结构下时延特征的研究对互联网结构与性能的理解具有重要作用。择取CAIDA Ark项目下分别位于4个不同地区的探测数据,提取网络时延与通信直径,发现网络时延与通信直径关系很小且超过70%的有效路径中存在支配时延。经分析,正是支配时延的存在影响了网络时延与通信直径的关系。对支配时延链路两端进行地理映射,发现支配时延以较高概率出现在同一国家同一城市某一链路传输之间。在此基础上,得出链路两端距离小于5 000 km的支配时延主要由排队时延组成,而链路两端距离大于5 000 km的支配时延主要由传播时延组成的结论。     

可充电无线传感器网络动态拓扑问题研究

在可充电无线传感器网络中的能量补给设备兼任数据采集设备的情况下,提出了可充电无线传感器网络时变动态拓扑模型,并在此基础上根据最大化能量补给设备驻站时间比为目标提出了最优化问题。通过分析不同时刻不同传感器节点和无线能量补给/数据采集设备的工作情况及需要遵循的约束条件,得到与原问题具有等优性的多状态线性规划问题。求解该优化问题,获得可充电无线传感器网络动态拓扑下的周期动态路由和无线能量补给/数据采集设备的工作策略。与之前的研究成果相比,优化目标值均有20%以上的提升。     

应用于CMOS图像传感器的联合降噪插值算法研究

提出了一种可应用于CMOS图像传感器的联合并行图像预处理算法,其中,色彩插值算法采用双线性插值法和边缘导向插值法相结合的方式来完成色彩还原,而降噪算法采用带阈值的空间自适应滤波降噪算法,在硬件语言描述算法时,将两种算法的处理过程进行了联合处理.实验仿真结果表明,通过对算法进行ISE仿真和Matlab显示处理,得到色彩饱和度较高的彩色图像,峰值信噪比(PSNR)为30～36 dB.整个处理过程有效地简化了片上系统(SOC)的图像处理过程,提高了算法的运算速度,节省了芯片面积且降低了系统功耗,为CMOS图像传感器的片上系统集成化设计提供了技术支持.