Investigation of precipitation selectivity and particle size concentration dependences in supercritical antisolvent method via online supercritical fluid chromatography

Supercritical antisolvent (SAS) precipitation technique, although being versatile and ecologically friendly, suffers from the lack of convenient methods for necessary thermodynamic parameters measurement. Recently we have proposed a method for solubility measurement in binary fluids based on an online hyphenation of supercritical antisolvent method and supercritical fluid chromatography (SAS-SFC). In this paper, we demonstrate the applicability of this method to the investigation of both selective precipitation from solution and particle size tuning in SAS using lower dicarboxylic acids as model objects. Measured solubility values adequately reflect selective crystallization from solution. SAS precipitation was observed only for those components, which concentration was above solubility in CO₂-solvent mixture as predicted by SAS-SFC method. Also, concentration dependences of particle size plotted in supersaturation coordinates instead of direct concentration in initial solution give additional insight into crystallization behaviour in SAS.     

基于电化学原理的飞机燃油箱氧浓度机载测量技术

飞机燃油箱惰化系统属飞机燃油系统设计中重要的分系统，为了准确评估燃油箱惰化系统的功能与性能，需要根据飞机实际使用剖面和惰化系统设计特点确定适用的飞行测试方法。提出了一种基于电化学原理的飞机燃油箱氧浓度机载测量方法，用于飞行实时测量运输类飞机油箱内无油空间或惰化管路的气体氧浓度，并对飞行中的实际影响因素进行模拟分析。经过分析飞行实际环境影响因素、关键传感器匹配性以及原理样机的试验验证等工作，将燃油箱氧浓度机载测量技术转化为专用的飞机燃油箱氧浓度机载测量系统，并通过了飞行实测考验。试飞结果表明，该项技术能够实时准确测量运输类飞机各种状态下的燃油箱氧浓度，满足飞机燃油箱惰化系统的效能评估要求。     

In-situ deflectometic measurement of transparent optics in precision robotic polishing

In the ultra-precision manufacturing of large optics, industrial robots have the potential to become an intelligent and economical choice of surface polishing. However, the transport of the workpieces between the polishing platform and the measurement instrument seriously limits the manufacturing efficiency. Therefore, an in-situ measurement system based on the monoscopic deflectometry is developed to determine the form quality of the optical lenses during rough polishing. Stray light reflected from the lower surface of transparent lenses may degrade the measuring quality, thus an effective absolute phase retrieval algorithm is developed to decouple the superposed fringes associated with the upper and lower surfaces. Then, the form of the upper surface under polishing can be reconstructed to guide the subsequent polishing. Experimental results demonstrate that the accuracy of the method is comparable to that of the coordinate measuring machine, consequently the manufacturing efficiency and reliability of large optical workpieces can be greatly improved.     

并联机器人末端轨迹测量系统设计

针对机器人末端轨迹检测问题，提出了一种基于拉线传感器的并联机器人末端轨迹追踪系统。该方案采用拉线式位移传感器与角度传感器作为数据采集端，经数据采集卡传递给计算机进行数据处理，实现末端轨迹测量。最后，设计试验样机并基于 Ｃ＃ ＷｉｎＦｏｒｍ 模块编写数据处理模块，从而实现仿真结果与实际相互印证的目标。     

Contamination of some foodstuffs marketed in Italy by fatty acid esters of monochloropropanediols and glycidol

ABSTRACT

Fatty acid esters of 3-monochloropropanediol (3-MCPD), 2-MCPD and glycidol (Gly) are food-processing contaminants that cause concerns about possible adverse health effects. The present study evaluates the contamination levels of the three ester classes in 130 samples of foodstuffs marketed in Italy covering 10 food categories, namely margarines, oils, roasted coffee, breakfast cereals, salted crackers, cookies, infant biscuits, rusks, breads and potato crisps. The analytical method employed is a so-called indirect method that entails MCPD/glycidol cleavage from their esterified forms, cleanup, derivatisation and GC-MS analysis. The MCPDs and glycidol concentrations (from esters) were found to be equal or a little higher than the levels reported in previous studies conducted in other European countries and described in the literature. 3-MCPD was the predominant compound in all foodstuffs analysed with the exception for rusks where Gly levels were slightly higher. Considering the sum of MCPD and Gly esters, the most contaminated foodstuffs were seed oils, followed by margarines and cookies, whereas roasted coffee, bread, rusks, cornflakes and infant biscuits were less contaminated with MCPDs and Gly concentrations often below LOQ or LOD values. Refined olive oil, potato chips and salted crackers showed contamination levels intermediate between the two above groups. The results of this study also confirm that the use of palm oil as an ingredient or frying medium is an important cause of increase of the levels of MCPD and Gly esters, especially in salted crackers, rusks and potato crisps. Finally, the Italian intake of 3-MCPD due to the various foods analysed has been calculated and related to TDI. The MoE for Gly was also estimated.     

云冈矿8602工作面进回风巷贯通测量的研究

综合机械化掘进工艺工作面走向越长,贯通距离越长,误差积累越大。以云冈矿8602工作面进回风巷道为例,提出了降低贯通测量误差的技术措施,实践结果表明贯通巷道偏差符合要求,贯通闭合实测误差符合设计要求。     

An indirect testing approach for characterizing pressure profiles of compression bandages and hosiery

As outlined in compression therapy literature, the performance of a compression textile can be characterized by its stiffness and interface pressure. In this study, an indirect approach for measuring pressure from a set of compression bandages and hosiery was developed, from which rigidity (EI) values were determined, and tension–elongation curves and pressure-elongation data were calculated. The calculated pressure values were compared against PicoPress sensor readings measured on 10 participants. Results showed that the correlation between both approaches varied among bandage and hosiery samples.     

基于约瑟夫森量子电压的交流功率测量系统及方法研究

基于约瑟夫森量子电压标准设计了交流功率差分测量系统。通过分析差分采样系统的误差分布及误差传递函数,提出换向差分测量方法,减小了差分采样系统的增益误差,提高了电压幅值测量准确度;通过分析衰减系数η,证明了采用换向差分测量较容易实现10-7量级电压幅值测量。通过评估差分采样系统零相位,结果证明了差分采样系统具有较好的相位测量稳定性。分析了交流功率差分测量系统的不确定度分量,评估了功率因数为1.0,0.5 L和0.5 C时的功率测量不确定度,通过与国家交流功率基准装置进行实验比对,证明了基于约瑟夫森量子电压交流功率测量系统不确定度评估的合理性。     

基于内隐测量的APP交互流程可用性评估方法

目的 研究内隐测量用于交互流程评估的普遍方法，选取适合的参考指标建立评估标准，旨在提出一套完整且通用的评估策略。方法 以带有拍摄功能的宠物社交类APP为载体，提出两种不同的交互流程，建立交互原型，并提取两套原型中差异较大的流程进行对比实验，采用眼动仪收集被测的无意识行为，依据首次注视时间、兴趣区域注视率，注视点图等指标分析实验数据，并与外显测量结果相结合，衡量用户操作情况以及APP的交互性能。结果 根据实验和数据分析，得出以拍摄界面为主页是更适合宠物社交APP的交互方式。结论 内隐测量评估作为一种新兴的产品可用性评估方式，不仅在交互界面设计评估上得到了广泛的应用，还可作为产品交互流程的评估方法，并具有深度挖掘的意义。     

基于量子线路逻辑运算的单光子量子态测量方案

在量子探测领域,关键任务之一就是要对未知量子态进行测量以获取量子态信息。通过将量子计算中的量子门所组成的量子线路应用于量子探测领域,提出实现单光子未知量子态的测量方案。利用量子计算的叠加性、纠缠性、可纠错性以及量子线路的可集成性,可以使得探测更具高效性并简化探测的实验系统。利用本文提出的探测新方案,通过仿真计算对该方案进行了模拟。在该方案的理论计算与仿真模拟结果的基础上,得到了以下的结论:通过在不同信噪比等参数的条件下选择适当的测量次数,基于量子线路的方案可以得到较为精确的测量结果。