Matlab-Simulink在浆水平衡中的仿真应用

以两级三段低浓除渣器为例介绍了Matlab-Simulink在浆水平衡中的应用.Simulink仿真步骤主要包括设备模块需求与分类、建立设备模块以及绘制仿真流程图.通过Excel计算和Simulink仿真计算对比,发现Simulink仿真可以降低设计的复杂性,提高计算的准确性,方便对计算过程和结果进行检验.     

智能粮仓的采集终端的设计与应用

设计基于ZigBee和LabVIEW的智能粮仓温湿度监控系统,由温、湿度采集节点、无线传输模块zigBee、主控模块,以及具有数据显示、分析、记录功能的LabVIEW上位机组成。用温度和湿度传感器对现场数据进行采集,再利用ZigBee无线传输模块将温湿度数据发送给ZigBee协调器模块,协调器再通过串口传给LabVIEW上位机,由上位机对各监测点的温湿度值进行显示、分析与处理,主控机根据接收到的指令对降温除湿设备进行自动控制,使粮仓内达到适温适湿的目的。通过开发功能齐全的粮仓监测软、硬件系统,为大型粮仓设施提供现代化、智能化的科学、高效的管理手段。     

搅拌设备的计算机辅助设计

本文建立了搅拌设备的计算机辅助设计的基本流程和步骤,介绍了搅拌器预选型模块、化学工程设计计算模块、部件的标准化模块、机械设计模块和经济分析与评价模块的基本结构和基本内容。为搅拌设备的设计提供了智能化的方法。     

网络计算机联锁仿真系统联锁功能的设计与实现

新型网络计算机联锁仿真系统采用网络技术、Web3D技术,实现对现场计算机联锁操作及各类信号设备的模拟仿真,具有广阔的应用前景。其联锁功能设计采用C#技术,依据计算机联锁程序执行原理,对计算机联锁操作命令形成模块、操作命令执行模块及进路处理模块进行设计,并部署在Web应用服务器及数据库服务器端,实现在客户端浏览器进行操作与仿真的功能。     

基于LabVIEW的烟支圆周检测系统软件设计

基于LabVIEW图形化编程语言和IMAQ Vision模块的图像处理功能,设计了烟支圆周检测软件系统,通过图像的对比度增强、中值滤波、图像分割、形态学运算、周长计算等算法编程,实现了烟支圆周的自动检测和数值显示。试验结果表明,系统的检测准确率在94%以上。检测系统具有智能化、检测精度高、功能可扩展等优点。     

升温型吸收式热泵在纸机干燥部的应用探讨

为解决纸机干燥部冷凝水系统末段存在冷凝水排出温度较高、吨纸蒸汽消耗大等问题,本课题提出应用升温型吸收式热泵（adsorption heat transformer, AHT）作为冷凝水系统余热回收设备。该设备可利用中间品位的余热与低温热源的热势差作为驱动,制取品位高于中间余热的热量,从而提高余热的利用率。本文在分析纸机干燥部蒸汽冷凝水系统热力系统现状及升温型吸收式热泵工作原理的基础上,给出了一种基于升温型吸收式热泵的多段供汽热力系统流程。通过LabVIEW仿真计算结果表明,应用升温型吸收式热泵的纸机干燥部蒸汽冷凝水系统具有更好的节能效果。     

基于LabVIEW的机械振动实验教学平台

针对机械振动这个实验教学项目目前存在的问题,结合LabVIEW和虚拟仪器在机械振动教学中的优点,利用虚拟仪器软件LabVIEW开发了机械振动实验教学平台中的部分仪器,构建基于LabVIEW的机械振动实验平台,实现软件代替硬件的功能。通过仿真运行,证明通过LabVIEW虚拟仪器技术和传统实验教学相结合,不仅很大程度上超出了传统仪器所能实现的功能,而且降低实验成本,提高实验效率,使实验教学更加生动形象,改善教学质量。     

基于智能化虚拟仪器的篮球鞋热湿舒适性测试系统研究

篮球鞋的热湿舒适性衡量篮球整体质量的重要指标。本文以LabVIEW等技术为基础开发了一种基于智能化虚拟仪器的篮球鞋热舒适性测试系统。该系统主要包含了仿真脚模、虚拟仪器等硬件模块，还包含了热湿舒适性测试软件等。测试结果表明：该系统可以很好地对篮球鞋热湿参数进行获取，极大地提升了篮球鞋热湿舒适性测试效率。     

基于虚拟仪器与PLC的食品仓储监控系统

针对我国食品储藏过程中人工逐点测量效率低、准确性差、人为误判断误操作等弊端,提出了一种基于虚拟仪器技术与PLC通讯的开发平台。该系统采用主从式工作方式,上位机采用PC机及LabVIEW软件,下位机采用PLC+EM231/2扩展模块,对温度、湿度、设备状态的数据采集、记录、存储和实时显示,并对超限量的参数进行自动调节和预警。     

以Labview为基础的轴承——转子状态监测软件系统的设计与实现

LabVIEW作为虚拟仪器的开发工具,功能强大的数据采集产品软件支持是其特色之一,因此使用LabVIEW进行数据采集十分简单、方便。本文详细介绍了利用LabVIEW提供NI-DAQmx数据采集驱动程序,结合数据采集设备NIUSB6008设计采集状态机。最终实现既定功能,并能实现在线数据分析和处理,还能扩展系统的功能。     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.     

低温带皮菜籽粕微粉的不同粒级部分的功能特性

为研究低温带皮菜籽粕微粉的不同粒级部分的功能特性,以经低温脱脂的带皮菜籽粕为原料,经微粉碎后筛分成212~425μm、150~212μm和106~150μm的3个不同粒级的微粉样品,检测这些样品的吸水性、吸油性、乳化性和乳化稳定性、蛋白质体外消化率。结果表明:1 3个不同粒级的微粉样品之间的粗纤维含量存在显著差异,表明三者的结构组成成分有一定差异。23个微粉样品的乳化活性和乳化稳定性随粒度级别的减小而显著增加(P0.01)。33个微粉样品的蛋白质体外消化率随粒度级别的减小而显著增加(P0.01)。4不同粒级带皮菜籽粕微粉样品的吸水性与吸油性受其结构组成物质不同和粒度的双重影响,与粒度的相关性不明显。     

Microbiology of food taints

Fresh and processed foods are often spoilt by the presence of undesirable flavours and odours caused by microbial action. The aim of this paper is to review the current knowledge of microbiologically induced taints that occur in a wide range of foodstuffs, including meats, poultry, fish, crustaceans, milk, dairy products, fruits, vegetables, cereals and cereal products. Examples have been chosen where the compounds responsible for the taint have been identified and sufficient data obtained to demonstrate the involvement of microorganisms. However, in some cases the full identity of the causative organism may not have been elucidated. The types of microorganisms covered by this review include bacteria, fungi, yeasts, actinomycetes and cyanobacteria. Although cyanobacteria do not in general infect foods, their presence in aqueous systems and water supplies can lead to off-flavours in aquatic organisms and processed foodstuffs. Several examples of each of these processes are discussed. Wherever possible, the likely biosynthetic pathway used by the microorganism to produce the offending compound in a foodstuff is indicated.