拉伸对光纤侧发光性能的影响

为探明轴向拉伸对光纤侧发光性能的影响,在不同温度下采用不同的伸长率拉伸光纤,利用BM-5A亮度色度计测量拉伸后光纤侧面的亮度,通过扫描电镜( SEM)观察光纤表面形貌,分析拉伸对光纤侧发光亮度的影响.结果表明,轴向拉伸可以提高光纤的侧发光亮度,拉伸伸长率越大,侧发光亮度越高.同时也发现温度对光纤侧发光亮度也有一定的影响...     

一种处理聚合物光纤侧发光的系统

开发了一种标准可重复的机械摩擦处理系统,能定量处理聚合物光纤,并且处理之后可直接检测光纤发光强度。以规格为D500的聚合物光纤为例,探讨了此平台处理光纤发光原理,并且从聚合物光纤的侧发光效果、物理形态和侧面发光强度的变化来检验系统的处理效果。试验结果表明:该系统可以有效且可控地处理聚合物光纤;处理次数不同,发光效果也不同。处理的光纤表面有明显的划痕和凹槽,且摩擦次数和聚合物光纤截面面积呈线性函数关系,相关系数达到0.998 19。在相同的条件下,随着处理的次数增多,光纤发光越强且发光位置距离光源越近,聚合物光纤侧发光强度越大。     

织造对不同结构光纤织物侧发光性能的影响

利用织造对光纤的损伤,制备结构简单、手感柔软的发光面料。通过探讨织造过程中光纤的损伤机理,比较不同组织结构光纤织物的侧发光强度,结果表明：织造对光纤的损伤主要发生在卷取过程中,光纤的侧发光主要是由于卷取轴的挤压和摩擦产生的破坏;不同组织织物的侧发光强度存在明显差异,其中平纹织物侧发光强度最小,纬缎织物最大;随着缎纹组织循环的增大,侧发光强度有增大趋势,但当增大到16枚纬缎时,与卷轴接触的光纤增加不明显,对发光的影响较小,这时光纤的弯曲起主导作用,因此从发光效果来看,16枚纬缎是较佳的选择。     

图案色彩可变换的光纤织物

为获得一种新颖的发光织物,将光纤与普通纱线交织提花,通过重纬组织设计使处于织物表面的光纤形成图案,并利用织物中屈曲的光纤产生侧发光,配合电路设计和控制单元设计,使发光织物中绿色宋体“福”字和红色草书“福”字交替出现,从而研制出可变换图案与色彩的发光织物“百福图”。光源由发光二极管提供,利用BM-5A亮度色度计测量发光织物的亮度,其亮度值为0.7～4.5 cd/m2,远远高于肉眼所能观察到的最低亮度。这种织物可用于各类装饰,并可开发为柔性织物显示器。     

蓄光膜面料发光性能的研究

为了探讨蓄光膜面料的发光性能,以D65光源为激发光源,研究蓄光膜面料在不同照度下、不同照射时间下的初始发光亮度及其发光亮度衰减规律。该试验结果表明,蓄光膜面料在D65的照射下,初始发光亮度随着激发照度(1000lx~2000lx,步长为500lx)增强而提高;而初始发光亮度及发光亮度衰减规律不随照射时间(5min~20min,步长为5min)改变而变化,表明在固定的照度下照射5min后其发光亮度已达到饱和。     

一种新型织物——发光织物的研制

设计并制作了-种柔性发光织物,将光纤按-定组织与普通纺织纤维交织织入织物.光纤表面组织形成部分织物图案,对所需发光处光纤进行表面处理,用发光二极管(LED)连接于光纤两端作为光源,通过电路设计、连接达到织物的发光.其中光纤表面采用化学试剂进行侧发光处理.对制成织物的发光亮度进行测试,结果表明发光效果明显,可用于舞台装饰、家纺、安全警示、柔性织物显示器等领域.     

可控发光织物的研制及其亮度表征

为开发一种制作简便,具有较好发光效果的织物,将PMMA芯端发光光导纤维按一定组织与普通纺织纤维交织,使光纤织物表面组织形成图案,对所需发光部分的光纤进行表面处理,通过电路设计,利用发光二极管提供不同颜色的光源,获得可控发光织物。其中光纤表面采用侧发光处理效果较好的正己烷与丙酮混合试剂处理。对所制成的发光织物的发光亮度进行测量,结果表明发光效果明显。该织物可用于舞台装饰、家纺、安全警示等领域,可进一步开发为柔性织物显示器。     

溶剂法制备侧面发光聚合物光纤的性能

选用丙酮与正己烷的混合溶液对端发光聚合物光纤进行处理,研究不同体积配比和不同处理时间对侧面发光聚合物光纤性能的影响。对处理后光纤的发光强度和断裂强力进行测试,并使用扫描电镜(SEM)对光纤表面形貌以及拉伸断裂后的断口形貌进行观察。结果表明:随着V丙:V正值的增大,光纤皮层组织先发生溶胀,后发生溶解反应,发光强度衰减程度先剧烈后平缓,光纤断裂强力依次递减;随着处理时间的延长,光纤皮层组织受损程度加剧,发光强度增大,光纤强力减小;当处理时间相同,溶剂体积比增大时,光纤静态拉伸加载的断口形态由粗糙变平整,倾斜角度减小。     

蓝色荧光对钻石颜色分级的影响

采用USB4000光纤光谱仪,在D65参照光源的条件下,测量各个色级不同荧光强度钻石样品的CIE1931色品坐标和主波长,根据色度学原理计算钻石样品的兴奋纯度和亮度纯度。结果表明,对于不同色级而相同荧光强度的钻石,随着色级的降低,钻石的主波长递减,兴奋纯度和亮度纯度递增,即钻石的颜色饱和度增加;对于同一色级的钻石,随着荧光程度的增加,钻石的主波长递增,兴奋纯度和亮度纯度呈减小趋势,强荧光至弱荧光可使钻石的兴奋纯度和亮度纯度上升1到2个色级,即不同程度的钻石荧光可使钻石颜色提升1～2个色级。     

夜光涂层织物发光性能

夜光涂层织物是一种新型功能性织物,采用余辉亮度测试仪测试涂层的余辉性能,分析不同发光材料的添加量及不同激发时间对涂层发光性能的影响,比较了涂层摩擦及水洗前后发光性能的变化.结果表明,随发光材料添加量的增加,涂层受光激发后的初始发光亮度增大,余辉时间达到10 h以上;当发光材料添加量增加到30%时,涂层余辉初始发光亮度达到1.298 cd/m2;涂层织物耐水洗性能优于耐摩擦性能.     

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.     

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