GC/MS/MS和LC/MS/MS在现代农产品分析中的应用

介绍了食品安全的影响及食品中有害物质分析的特点，着重介绍了GC／MS／MS和LC／MS／MS法在食品中的农药残留和兽药残留的分析应用。     

环境介质中有机污染物分析前处理方法概述

概述了环境介质中有机污染物样品前处理常用技术和新型技术。针对不同沸点的有机污染物采用的分析方法不同,将其分为挥发性有机污染物和半挥发性有机污染物分别讨论。介绍了固体和液体样品中挥发性有机物的顶空法,大气中挥发性有机物二次热解析GC／MS联用测定技术,大气中半挥发性有机污染物被动采样技术,水样中半挥发性有机物的固相革取手段,土壤沉积物和固体废弃物中半挥发性有机污染物各种常用提取手段的优劣,柱色谱净化和凝胶渗透色谱净化的应用原理以及常用浓缩手段的特点。     

联用分析技术的现状

联用分析技术是当前仪器分析和分析仪器发展的主要方向之一。联用以后既能提高分析的灵敏度和准确性以及完成复杂混合物分析的能力,还能导出一些新的功能。目前已经有了GC/MS、LC/MS、GC/FT-IR、LC/NMR、GC/ES、LC/ES、LC/AA、MS/MS等多种方式的在线联用技术,其中以GC/MS最成熟;而LC/MS、GC/FT-IR、GC/ES和MS/MS等也都有了商品仪器。GC/MS正沿着三高(高效色谱柱、高分辨质谱仪和高沸点试样)的方向发展。数百个组分的分析,10~(-9)克含量的鉴定,及高达50个碳以上蜡类测定皆可用GC/MS进行。LC及MS在性能和要求上有矛盾,是否宜于在线联用尚有争议。但愈来愈多的人认为,在线联用方案较为可取。为此,不少人正在努力改进离子源,使加入接口,以便实现直接连接。但迄今Lc/Ms联用尚有许多问题需要解决。载气对IR无干扰是Gc/FT-IR的一大优点。由于光管的改进,并采用了毛细管色谱柱,鉴定极限可达10~(-9)克,使灵敏度和速度等方面都满足了联用的要求。ES中的MIP与GC联用在1973年已有商品仪器,它可同时测定数十种金属和非金属元素,对有机物也能提供实验式。MS/MS对分析的化合物有较高的选择性和鉴别能力。在试样蒸汽压,瞬时分离和分离效能等方面,MS/MS较GC/MS有一定的优越性。     

现场质谱及气相色谱/质谱联用在环境有机污染监测中的应用

近几年,国外现场质谱(MS)及气相色谱/质谱联用(GC/MS)分析技术发展得很快.实验室的台式分析仪小型化、引入集采样与分析于一体的直接质谱法均有利于对环境中挥发及半挥发性有机物进行实时、原位的测定.固相萃取及快速色谱等技术的应用使现场分析的准确度、精密度有很大提高,扩展了现场分析技术的应用范围.本文介绍了国外现场MS和GC/MS用于有机污染物监测的最新发展动态,并阐述了我国相关领域的现状和存在的问题,同时提出了解决方案,为有关部门进行环境有机物的现场监测提供了技术依据.     

国产微流量LC/TOF-MS联用仪在食品安全检测中的应用

上海精科-复旦分析仪器研发实验室开发的微流量LC／TOF—MS联用仪是国内首创的通用液质联用系统。它的NanoLC部分采用了新型热膨胀高压泵体,实现了无活动部件的微流高压梯度HPLC;质谱部分使用先进的TOFMS技术,能够完成多数的LC—MS检测工作,并保持较低的拥有成本。在食品安全领域,该仪器可以检测苏丹红等有害物质。     

流动注射分析（FIA）及其在环境监测中的应用

由于ＦＩＡ具有快速,省时,省力,测量精度度胶便于实现自动化等特点,倍受国内,外环境监测工作者重视。本文介绍了ＦＩＡ技术的特点及其在环境监测中的应用。在应用技术中介绍了典型的ＦＩＡ系统和以ＦＩＡ为基础的自动在线监测体系。引用文献４８篇。     

红外线法与紫外线法测定大气中CO浓度可比性研究

QGS—08型红外线气体分析器属于不分光式红外线法,由北京分析仪器厂从西德麦哈克(MAIHAK)公司引进,这种仪器具有国际先进水平。现已应用于大气自动监测系统连续监测大气环境中一氧化碳(下称CO)浓度。 CO-2型一氧化碳测定仪属于原子吸收型紫外线法,由卫生部指定江苏省金坛分析仪器厂定点生产,灵敏度较高,已广泛用于环境监测。     

长光程差分吸收光谱仪简介

长光程差分吸收光谱仪是一种新型在线式大气自动监测系统,可同时对多种气体进行连续监测,并具有远程监测能力。获得的数据则计算机进行处理,可实时记录空气中各种污染物的含量。本文对仪器结构和工作原理作了简单介绍。     

可立快(CliquidTM)食品安全分析新技术

介绍了美国应用生物系统公司针对食品安全开发的最新技术可立快（Cliquid^TM），极大地简化了LC／MS／MS对食品中各种残留污染物进行常规分析的操作。为食品安全提供了简单、快速准确地解决方案。     

GC-MS3100型气相色谱(四极)质谱联用仪荣获BCEIA 2007金奖

GC—MS具有强有力的定性、定量能力及功能强大的数据处理系统，越来越受到实验室分析工作者的青睐。以前采用GC建立的检测标准逐渐被气相色谱质谱联用技术所取代，其在环境监测领域、食品安全领域、科学研究领域和工业等领域占有很大的比重，需求量呈逐年上升之势。     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

ANGULAR DISTORTION ALLOWABLE VALUE AND ASSESS METHOD OF WELD ON COKE TOWER

A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mm×28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.