Threonine-FX dosimeter for food irradiation

A detailed study for the spectrophotometric readout method for L-threonine powder, [CH₃CH(OH)CH(NH₂)COOH], was done. In this method, 400 mg unirradiated/irradiated L-threonine powder was dissolved in 10 ml of a solution which contains 3×10⁻⁴ mol dm⁻³ ferrous ammonium sulphate and 1.7×10⁻⁴ mol dm⁻³ xylenol orange (XO) in aerated aqueous 0.17 mol dm⁻³ sulphuric acid (FX). The peroxy radicals produced from irradiated threonine oxidize ferrous ions and XO forms a complex with ferric ions as well as controls the chain length of ferrous ion oxidation. The plot of absorbance at 556 nm against dose is linear in the dose range 20–400 Gy and doses down to about 1 Gy can be measured using 10-cm path cells. Response of the dosimeter is independent of irradiation temperature above 20. A dose of 50 Gy–10 kGy can be measured dissolving 50 mg threonine powder in 10 ml of a solution which contains 3×10⁻⁴ mol dm⁻³ ferrous ammonium sulphate and 1.3×10⁻⁴ mol dm⁻³ XO in aerated aqueous 0.06 mol dm⁻³ sulphuric acid (FX). The plot of absorbance at 552 nm against dose is non-linear. However dosimeter shows linear dose response up to 1000 Gy. Irradiated threonine powder is stable for about 3 months. The reproducibility of the method is better than ±2%. This dosimeter is very useful as transfer dosimeter for food irradiation programme.     

基于USB3.0 主模式高速接口卡设计

针对现行USB2.0接口已不能满足现代大容量数据高速度传输需求,提出一种基于USB3.0和FPGA的高速传输的解决方案。该方案通过配置可编程接口把EZ-USB FX3设置成master主模式,优化DMA数据传输通道,实现了电脑与接口卡之间数据高速传输。文章详细地介绍如何提高传输速度的方法,经实际传输测试,该接口卡能在传输速率高达350Mbyte/s依然能保持正确无误的高速传输。     

一种基于USB接口的新型激光编码器设计

介绍了一种新型激光编码器的设计方法．主要利用USB微处理器EZ—USBFX2（CY7C68013）的GPIF和固件下载等特性进行构建,分析了该编码器的硬件和USB固件、客户程序等的设计．并开发了相应软件．     

随机波动率跳-扩散模型下外汇期权本外币对称公式

外汇期权本外币对称公式表示本币看涨/看跌期权与外币看跌/看涨期权用同类定价函数表示的等价关系.通过测度变换法指出本币测度下的Bates模型和Heston模型在外币测度下保持模型类型不变,并且由此证明这两个模型下的本外币对称公式,其中的定价函数由Attari公式给出.数值分析给出了本外币对称公式的应用示范,并且详细分析了Attari公式的计算速度优势.     

非线编如何选择电脑显卡

本文主要介绍非线性编辑系统中专业显卡的选择，比较了NVIDIA与ATI显卡芯片的产品线，并针对不同的应用环境推荐了相应的显卡。     

电容式套管卷绕机的S型切割控制技术

本文介绍了电容式套管卷绕电控系统中S型切割控制技术。采用日本三菱公司的FX3U系列可编程控制器(PLC)控制步进电机实现S型切割控制。     

变频技术在煤矿通风机控制系统中的应用设计

在国内对能源需求不断加大的今天,如何高效地发挥电能作用在广大厂矿企业中受到人们越来越多的重视,此外,保护环境、减少污染也越来越多地受到人们的关注,文中利用国外流行的变频技术对传统煤矿通风机系统进行改造,做到了最大程度的节能减排,智能控制监控技术在系统中的应用,使生产过程中的电能利用和污染物的排放得到有效的管理.     

EZ-USBFX2接口在生物电信号数据采集系统中的应用

摘要：介绍EZ．USBFX2的结构和功能;给出基于EZ—USB FX2,FPGA控制A／D转换实现的生物电信号数据采集系统;重点说明了基于GPIF主控制方式的EZ—USB FX2接口设计及相应固件程序开发,并给出GPIF波形设计方案。     

用触摸屏和PLC实现四人抢答器的控制设计

用触摸屏和PLC(可编程逻辑控制器)实现控制是现代工业控制中的一种新方法。文中基于三菱F940GOT-LWD-C型触摸屏和FX0S-30MR型PLC,提出了4路抢答器控制系统。描述了触摸屏的工作原理及特点,阐述了控制系统硬件与软件设计方案,实现了对四路抢答器的监控。系统软件设计包括触摸屏端的画面运行系统的设计和基于顺序功能图的控制程序设计。实际应用表明,该系统具有运行稳定、可靠性高、实用性强等特点。     

The modified Casson＇s equation and its application to pipe flows of shear-thickening fluid

A few additional data from our previous experiments were plotted to emphasize the shear-thickening behavior of deoxy sickle erythrocyte (SS) suspension. A constitutive equation (named as FX equation) was developed and applied to a cylindrical pipe flow of a shear-thickening fluid. A blunt velocity profile and its volume flow rate were calculated. The flow was non-viscous (potential) in the central part of the pipe (i.e. the central core or the central plug-flow), and became more and more viscous towards the wall of the pipe after a specific radial distance, which was determined by a critical shear rate of (named as Fungs shear rate). Furthermore, combining the FX equation with the original Cassons equation, the author obtained a modified Cassons equation by introducing .The English text was polished by Yunming Chen.