机电设备安装调试技巧研究

在现代社会生产中,机电设备应用十分广泛,决定着生产的效率与安全,所以,做好机电设备安装调试有着重要现实意义。文章在分析机电设备安装调试问题基础上,探讨相应的安装调试技巧,为机电设备实际安装调试工作提供借鉴和帮助。     

论电气设备安装和调试的重要性

随着我国工业发展进程的不断加快,生产制造类的工厂的机械设备也在不断增多,这对于提高生产企业的生产效率,提高生产产量具有重要的的影响,而在诸多电气设备安装使用过程中应做好安装的准备调试工作,以防止安装或调试电气设备出现问题导致的安全事故隐患或影响日常的生产工作。本文则根据我国工厂中电气设备现状,对电气设备的安装及调试情况进行分析,做出电气设备的质量控制,从而说明电气设备的安装及调试的重要性,以供参考。     

Oslo型蒸发结晶器在Na_2SO_4型卤水中的应用

本文介绍了Oslo型蒸发结晶器应用于Na2SO4 型卤水生产大粒盐的设计、生产原理、生产调试等 ,同时介绍了调试过程中遇到的问题及处理方法。     

热工调试自动化系统的可靠性探讨和分析

为了防止电力生产过程中发生重大事故,保证电厂的安全,必须提高热工调试自动化系统的可靠性。鉴于热工调试自动化系统是一个复杂的系统,目前的设计和维护工作中还存在诸多困难。文章主要分析热工调试自动化系统可靠性研究的背景,对影响其可靠性的因素进行探讨,从热工调试自动化系统的设计、安装调试、维护管理等方面来保证其可靠性,以维护电厂的安全,防止电力生产事故的发生。     

Oslo型蒸发结晶器在NaSO4型卤水中的应用

本文介绍了Oslo型蒸发结晶器应用于Ns2SO4型卤水生产大粒盐的设计、生产原理、生产调试等，同时介绍了调试过程中遇到的问题及处理方法。     

张力分段在无碳复写纸生产中的应用及张力传感器的选型

在无碳复写纸生产过程中张力调整及张力传感器的选型十分重要。若调式、选型不当会影响正常生产,延长调试周期,造成一些不必要的浪费,尤其是新机调试因张力设定或张力传感器的选型不当,会导致长时间不能正常生产。笔者根据多年参加不同类型的无碳纸设备的设计、安装、调试、选型总结了一些经验,以期为无碳复写设备在张力控制及其选型方面提供一点借鉴。     

电气仪表自动化安装与调试

电气设备在企业生产中普及应用的同时,电气仪表自动化安装与调试工作备受人们关注。电气自动化仪表的安装与调试工作较为复杂,文章针对电气仪表在安装与调试中需要遵守的基本要求和注意事项做了具体介绍,以某水泥厂为例,针对电气仪表在安装和调试中易出现的问题和应对方法做详细阐述。     

基于PC-DMIS系统试制阶段白车身测量程序运用于正式造车测量的方法

大中型汽车企业都有试制车身车间和一定数量的生产基地,如果试制车间和基地的三坐标测量设备相同,试制阶段的测量程序经过少量的修改和调试就可以直接用在生产基地的量产车测量中。文章介绍了在PC-DMIS系统下,试制车间经过脱机编程及在线调试,将程序输出给基地,基地经过少量调试后,该程序直接用在了量产车的测量中,节省了基地约60个小时的时间。     

浅析电子电路设计常用调试方法与步骤

在电子电路的设计过程中,电路的调试占有重要地位,这是理论联系实际的重要环节。电路只有通过调试,各项性能都达到预期要求,才是一个合格的设计,因此我们应该重视电路的调试工作,使之更为完善,这样才能设计出更符合实际生产要求的电子装置。     

浅析火电厂DCS控制系统现场调试

DCS系统也称为分散控制系统,其在生产过程中对多个回路进行分别控制,但其数据又可集中进行获取,集中管理和集中控制,所以在火电厂生产,DCS系统作为重要的设备之一,实现对电厂的控制和监视职能,对火电厂的正常运行具有非常重要的意义。因此,加强DCS控制系统的调试工作是火电厂非常重要的工作。文章从DCS系统调试前的检查入手,分析了DCS系统调试的主要方法,并进一步对DCS控制系统现场调试中的故障诊断和处理进行了具体的阐述。     

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.     

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.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H₂O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.     

European priorities for research to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the