全自动离心判读仪的研制

离心判读仪是以离心力来分离液体中悬浮颗粒或分离不同密度液体的一种医疗器械。当前此类设备大多依靠人力装夹、人工判读,耗费大量人力,判读标准化程度低。全自动离心判读仪采用PLC技术,集装夹微柱凝胶卡,判定有效性,离心和对离心结果进行判读等一系列动作于一身。减少了人力资源浪费,提高了判读准确性。判读仪控制系统主要由工控机、欧姆龙PLC及相关配套设备组成,判读的结果可在上位机中直接显示;另外还有自我学习功能,在一定程度上改变了传统微柱凝胶卡实验的过程。     

多道脉冲幅度分析器在中子活化多元素在线分析仪中的应用

介绍了基于脉冲幅度分析器的中子活化多元素在线分析仪中在有色金属领域的应用。中子活化多元素在线分析仪应用到有色金属领域,可以提高生产过程的控制指标、提高生产效率、节约生产成本,对有色金属领域的生产过程具有重要意义。     

基于PC机的虚拟逻辑分析仪的设计

逻辑分析仪的测试对象是数字系统中的数字信息，其结构复杂，成本较高。所述的是基于虚拟仪器概念的虚拟逻辑分析仪的设计思想和方法，由于部分硬件功能软化而使硬件电路大为简化，从而降低了仪器成本，提高了逻辑分析仪的可靠性和性能。重点阐述了基于PC机的虚拟逻辑分析仪的硬件电路设计和软件设计部分。     

VMA1000胶料流动性分析仪在橡胶加工中的应用

针对目前橡胶行业普遍运用门尼黏度表征胶料加工流动性的现状,阐述了门尼黏度与流动性的不同以及产生流动性差异的原因。重点运用新型VMA1000胶料流动性分析仪,对实际胶料生产进行检测与质量控制,分析了影响胶料加工流动性的因素和流动性对橡胶加工的重要意义。     

MEMS质谱仪研究综述

近年来,小体积、低功耗、价格低廉、使用方便的MEMS质谱仪成为了质谱领域的研究重点和热点。目前国外对MEMS质谱仪及其相关技术的研究已取得了一些成果,甚至研发出了较为完整MEMS质谱仪。但是整体而言,MEMS质谱仪的性能还很低,其研究主要还处于对其元件分别进行微型化的阶段。其中,MEMS离子源以对电喷雾离子源的研究为主;MEMS质量分析器以对离子阱的研究为主;MEMS离子检测器以对法拉第筒的研究为主。本文总结了MEMS质谱仪的最新成果,同时分析了可能面临的问题。     

矢量网络分析仪的校准方法

该文简单介绍矢量网络分析仪的工作原理,重点阐述误差修正原理以及与误差修正相关的校准件、校准方法和如何进行校准质量的评估。     

提高智能排气分析仪精度的研究

作者介绍了一种能够有效提高智能排放分析仪测量精度的新校准方法,并重点分析了用正交变换作最小二乘对标准气体的浓度取样点进行函数拟合,提供了一种能方便地在小型嵌入式系统中实现高精度校准的理论依据。试验结果表明,采用这一方法完全能达到±2%的精度,该方法具有一定实际推广意义。     

Sub-micrometer particulate air pollution and cardiovascular mortality in Beijing, China

Background

While the link between particulate matter and cardiovascular mortality is well established, it is not fully investigated and understood which properties of the aerosol might be responsible for the health effects, especially in polluted mega-city areas.

Objectives

Our goal was to explore the association between daily cardiovascular mortality and different particle metrics in the sub-micrometer range in Beijing, China.

Methods

We obtained daily counts of cause-specific cardiovascular deaths in the Beijing urban area for the period March 2004 to August 2005. Concurrently, continuous measurements of particle number size distributions were performed. Particle number concentrations (NC) between 0.003 μm and 0.8 μm were converted to particle mass and surface area concentrations assuming spherical particles. Semi-parametric Poisson regression models adjusting for trend, seasonality, day of the week, and meteorology were used to estimate immediate, delayed and cumulative particle effects. Additionally, effect modification by air mass origin was investigated.

Results

We observed associations between daily cardiovascular mortality and particle NC for a 2-days delay. Moreover, nearly all particle metrics showed 2-days delayed associations with ischemic heart disease mortality. The strongest association was found for particle NC in the size range 0.03-0.1 μm (7.1% increase in daily mortality with a 95%-confidence interval of 2.9%-11.5%, per an increase of 6250 particles/cm³). Results for surface and mass concentrations with a lag of two days indicated effect modification by air mass origin, whereas effects of particle NC were not modified.

Conclusions

Results show an elevated risk of cardiovascular mortality in Beijing from short-term exposure to particulate air pollution in the sub-micrometer range. Results also indicate that locally produced smaller particles and regionally transported particles may exhibit different effects in Beijing.     

Effects of Na2CO3 and NaOH on Pasting Properties of Selected Native Cereal Starches

ABSTRACT: Using a Rapid Visco Analyzer (RVA), it was revealed that 2 alkalizing agents (Na2CO3 and NaOH) had a far larger effect on pasting properties of nonwaxy starches (wheat, corn, rice) compared with their effect on waxy starches (waxy corn and waxy rice). It was hypothesized that the alkalizing agents have a greater propensity to attack the amorphous regions of the nonwaxy starch granules, thereby causing increased leaching of amylose molecules and possibly also some hydrolysis of starch chains. As a result, the RVA pasting profile of a nonwaxy starch, in the presence of alkali, was drastically altered to one that more closely resembled that of its waxy counterpart without added alkali.     

Use of Ozonation for Polymer Microstructure Characterization: Analytical Aspect of the Ozone Application

Ozonation is suggested as an effective tool for polymer microstructure characterization. It consists of the selective estimation of the carbon - carbon double bonds content (less than 0.01% mass) and their distribution within polymers. The developed technique consists of measuring the ozone absorbed by the olefin double bonds according to the ozonation reaction. The measurements were carried out by the “Double Bonds Analyzer” (DBA) device. The comparison of the proposed simple and quick method with traditional ones, like GPC, shows good correlation.