纳米金刚石复合镀钢领的制备与工艺优化

为探讨纳米复合镀层钢领的表面粗糙度、显微硬度、磨损率和成纱毛羽及断头率的影响,制备了纳米金刚石复合镀钢领。运用纳米金刚石复合镀技术制备四层纳米复合镀钢领,选择制备过程中纳米金刚石含量、施镀温度和PH值等3项主要工艺参数,进行了3因素3水平正交试验。结果表明：较优的制备工艺为纳米金刚石含量20g/L、温度85℃、pH值5.0。认为,镀前预处理工艺对钢领电镀质量有着重要影响,通过正交试验可获得较优的制备工艺参数,制备出表面光洁度好、硬度高、磨损量小,成纱质量较优、使用寿命明显延长的的纳米复合镀钢领。     

纳米金刚石复合镀钢领的制备及工艺优化

为探讨纳米复合镀钢领的表面粗糙度、显微硬度、磨损率和对成纱毛羽及断头率的影响,制备了纳米金刚石复合镀钢领。运用复合镀技术对普通钢领表面进行处理,选择制备过程中纳米金刚石含量、施镀温度和pH值3个主要工艺参数,进行了正交试验。结果表明:较优的制备工艺为:纳米金刚石含量20 g/L、温度85℃、pH值5.0;制备的钢领表面粗糙度为0.18μm,显微硬度为635.8 HV,磨损量为1.4%,成纱毛羽指数为2.18,断头率为3根/(千锭·h)。     

镍-磷-纳米碳化硅-聚四氟乙烯化学复合镀对纺纱钢丝圈寿命的影响

为研究分析不同表面处理工艺对钢丝圈纺纱性能的影响,进一步提高钢丝圈使用寿命,采用化学镀的方法向镀液中添加纳米碳化硅(SiC)和聚四氟乙烯(PTFE),制备Ni-P-SiC-PTFE化学复合镀层的钢丝圈。借助扫描电子显微镜、X射线能谱仪和环锭纺纱机等对钢丝圈及镀层的微观结构和性能进行表征。结果表明:相对于Ni-P 化学镀钢丝圈,Ni-P-SiC-PTFE化学复合镀钢丝圈的镀层晶粒细化,厚度均匀,镀层与基体之间结合良好,镀层厚度增加1倍,镀层硬度提高24.5%;采用Ni-P-SiC-PTFE化学复合镀钢丝圈试纺后,纱线的细节、粗节和棉结分别降低40%、18.8%、10.3%,且钢丝圈挂花引起的断头率降低50%,纺纱性能优于Ni-P化学镀钢丝圈;Ni-P-SiC-PTFE化学复合镀钢丝圈上机后的磨损量减少了31.6%,耐磨性得到明显提升。     

超洁平面钢领的性能特点及纺纱实践

钢领是环锭纺设备的关键部件,其质量的优劣决定着纺纱能否顺利进行,影响着成纱毛羽,同时也决定着生产费用的高低.平面钢领是目前使用最为普遍的一种,表面硬度和光洁度是其优劣的关键因素.表面硬度高而光洁度差的钢领,纺纱张力大而且不稳定,钢丝圈也易磨损;硬度低的钢领虽然表面光洁,但使用中易被钢丝圈磨成沟痕,经纱张力不稳定,成纱毛羽增加,钢领衰退期快,使用周期短,不利于降低成本.     

陶瓷复合材料钢领的使用效果

为了解陶瓷复合材料钢领的性能及使用效果,对其表面硬度、粗糙度及金相组织图进行了测试,并与进口钢领、国产普通钢领进行了纺纱对比试验.结果表明:陶瓷复合材料钢领表面硬度高,表面光洁,耐磨性和自润滑性能好,细纱千锭时断头达到企业内控标准,成纱毛羽少.     

钢领表面化学镀镍磷合金工艺的研究

为了提高钢领性能,延长使用寿命,针对纺纱钢领酸性化学镀镍磷的工艺进行了研究;着重研究了温度、pH值及络合剂对镀层沉积速率和表面形貌的影响,以及不同加热温度对钢领表面硬度的影响;以试验的方法得出最佳镀覆工艺为:化学镀温度应控制在80℃,pH控制为5.0时可获得最佳镀速和含磷量镀层;采用柠檬酸、乳酸、硼酸三种络合剂配合使用,可提高镀液的稳定性和钢领表面性能;镀镍磷合金钢钢领热处理温度最佳为350℃,不能超过400℃.     

钢丝圈磨损机理及等离子体渗硫钢丝圈

为了解决纺纱钢丝圈磨损问题,分析钢丝圈热磨损和热粘着撕裂磨损的机理,探讨钢丝圈—钢领摩擦因数及等离子体渗硫技术在钢丝圈表面处理上的应用效果.指出:钢丝圈磨损的机理是先氧化磨损、粘着撕裂磨损,以及退火后硬度下降、圈形改变、开口变大甚至烧毁失效;钢丝圈—钢领摩擦因数宜控制为0.3左右;利用硫化亚铁(FeS)的无油润滑性能及摩擦因数小的特性,在钢丝圈表面渗FeS润滑层,可使钢丝圈具有优良的抗热粘着磨损性能、稳定且较小的摩擦因数、运行平稳,达到纺纱气圈稳定,有利于纱线质量的提高并延长钢丝圈使用寿命.     

布雷克钢领钢丝圈的使用体会

分析布雷克钢领钢丝圈在使用过程遇到的问题和注意事项。简述了钢领钢丝圈对纺纱的影响。在对钢领直径和钢丝圈质量、弓形进行优选的基础上,做好钢领钢丝圈的上机准备和磨合工作,并对钢丝圈磨损通道和纱线磨损通道进行科学分析与调整,保证了成纱质量。认为:布雷克钢领钢丝圈的合理选型和科学磨合可以有效提高成纱指标。     

纺纱钢领研发现状及陶瓷合金钢领

为促进钢领的技术研究,根据当前国内外钢领、钢丝圈研究现状,分析了我国在钢领、钢丝圈研究方面存在的差距.重点介绍了纳米陶瓷合金钢领的研究状况、加工工艺及试用性能.指出:提高钢领表面硬度、延长钢领使用寿命、提高纺纱质量是今后钢领、钢丝圈研究发展的方向.应加强钢领、钢丝圈配套研究才能达到持久耐用的效果.纳米陶瓷合金钢领可提高钢领表面硬度,降低表面粗糙度,增加钢领的耐磨性能,延长钢领使用寿命.具有性价比高、走熟期短、使用周期长等优点.     

钢领与钢丝圈的应用及发展

为了提高纺纱质量、减少千锭时断头,介绍了钢领、钢丝圈的型号规格、要求及选配方法;从上机前管理、使用管理、周期管理及日常使用注意事项等方面详述钢领与钢丝圈的精细化管理要求及其对纺纱生产的影响;从适应性、配合状态及表面处理等方面探讨提出二者的发展趋势。指出:纺织企业应依据原料、纺纱品种、纺纱号数以及生产实际等合理选配钢领、钢丝圈,并对二者进行精细化管理;制造企业应配套研发钢领与钢丝圈,提高二者的匹配性能,注重提升表面处理技术,以更好地发挥其配套性能,稳定纺纱质量;满足纺纱断头少、成纱质量好的要求,产品适应性强、适用高速纺纱、寿命长等是钢领与钢丝圈的发展方向。     

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