YG191XH型智能条干毛羽仪的波谱图曲线图分析

为了分析纺纱过程中纱疵产生的原因,采用YG191XH型智能条干毛羽仪对纱线毛羽进行波谱检测,根据条干、毛羽波谱图和曲线图可以观察纱线品质,查找产生疵病的根源。文章进一步从机械、工艺和操作实例入手,结合毛羽波谱图和曲线图进行分析,为纺纱提供较好的检测方法,以制定最佳工艺条件。     

几种纱线长片段不匀跟踪分析

探讨纱线长片段不匀的跟踪分析方法。以脉冲式、波浪形长片段不匀以及并条机前胶辊表面割伤为例,阐述了纱线规律性长片段不匀跟踪分析的过程;以混并二道并条机部件缺陷、抗静电剂使用不当为例,阐述了纱线无规律性长片段不匀跟踪分析的过程,分析了各案例中曲线图和波谱特征以及相互间的联系、产生疵病的原因、消除方法和效果,说明了实际生产中如何利用条干仪分析追踪和解决纱线长片段不匀问题的方法。认为,充分利用条干测试提供的信息,可以比较迅速准确地找到长片段不匀形成的原因,及时消除质量疵病,保证成纱质量的稳定。     

配棉及落棉对常发性纱疵的影响

常发性纱疵是一种纱条截面积变化较小、长度较短的疵点。常发性纱疵的细节、粗节和棉结可在乌斯特条干均匀度仪上测得,这些疵点直接影响纱条的短片段条干不匀及布面质量,是目前我国棉纱质量与国际水平的主要差距所在。常发性纱疵的产生涉及的因素很多,贯穿于纺纱生产全过程,诸如纺纱原料、工艺设计、机械设备、温湿度、操作以及运转管理等等。我     

棉纺规律性条干不匀的检测

棉纺规律性条干不匀是成纱主要疵点之一,对织物外观和内在质量影响很大.规律性条干不匀具有波的特性,可用条干仪、布面分拆称重等方法测试其波长,再根据推导出的规律性条干不匀波长和缺陷部件转速的计算公式,可诊断产生纱疵的工序及机件.介绍了诊断的方法及步骤,并列举了实例;总结了常见规律性条干不匀的形成原因及波长范围,介绍了规律性条干不匀的有关计算公式在开发计算机纱疵分析软件中的应用.     

Y311条干仪智能化研究

利用Ｙ３１１条子、粗纱条干均匀仪的机械式检测装置，接电涡流位移传感器及单板机构成纱条不匀信号的数字处理系统，对纱条进行测试，给出了表明纱条不匀的变异系数ＣＶ％值、方差、纱条经压缩后的平均厚度、离散率以及波谱图。试验结果表明：以数字信号处理技术为基础，应用计算机业分析纱条不匀，成本低、效率高，功能强，结果准确、可靠，便于进一步开发。进行这项工作，不仅为分析纱条不匀提供了新的手段，为研究纱条不匀测试仪     

并条工序的质量检测与控制

并条工序中棉条波谱图机械波、牵伸波、山形机械波和不匀曲线图周期波会直接影响后道工序的纱线质量。通过经验分析及使用专家分析软件,找到产生纱疵的设备隐患,及时反馈,以减少降等降级疵布。     

POY条干不匀图型分析

POY的片段不匀,即通常所谓的条干不匀,Uster不匀曲线图与波谱图,能比较准确清楚地反映出这些不匀片段以及分布情况。各种影响条干不匀的因素有不同的不匀图型反映,本文从图型研究的角度出发,分析几种主要的影响因素,从而指导生产,提高质量。     

并条12cm～14cm机械波的实例分析

分析并条波谱图12 cm～14 cm处机械波产生的原因。利用电容式条干均匀度仪检测纱条条干不匀,通过延长其测试时间,使检测波长达到或超过25个,以保证波谱图的可信度;同时根据不匀曲线图计算对应在并条波谱图上的机械波波长值,经分析及试验验证后认为:并条机一罗拉或传动一罗拉的齿轮或轴承出现了问题,都会造成并条12 cm～14 cm的机械波。     

毛精纺纱条不匀的波谱分析

随着纱条不匀理论研究和乌斯特条干波谱仪的发展，目前已能迅速、有效、简易地测试和判析各种纱条不匀率CV值的不匀结构，从而对纺纱生产过程进行质量监控，确保生产过程平衡有序地进行。在生产实践上，具有相近但不同短、中、长片段不匀率数值的纱条，其不匀直观冈邰呈现各不相同的形念，织入布后其布面可能显示差异极为显著的不同形念，说明不匀率数值本身并不能全部表达纱条不匀的性能；     

再论气流纱条干不匀的成因

文章叙述了作者在长期生产实践中,发现和解决气流纱条干不匀的经验,文中列出的各种有代表性的波谱图和具体的分析方法可供有关各厂分析气流纱条干不匀时参考。     

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