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为研究紫外线吸收剂对改善涤纶织物吸收紫外线性能的影响,将5只苯并三唑类紫外线吸收剂经分散后用高温高压浸染法使其上染到涤纶织物上,以残液法测试紫外线吸收剂对涤纶的上染率,用紫外线透过率表征织物的紫外线吸收性能。结果表明:选用的紫外线吸收剂可以在130℃下保温40~60min上染涤纶织物,紫外线吸收剂结构、分子质量、上染温度和用量都会影响其对涤纶的上染率,分子质量适中、芳环较多、疏水性基团比例较高的紫外线吸收剂对涤纶的上染率较高;上染率较高的紫外线吸收剂能更明显地改善涤纶织物的紫外线吸收性能,上染率不够高但分子中含有2个分子内氢键螯合环的紫外线吸收剂也能明显提高涤纶织物的紫外吸收能力。 相似文献
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提高低共熔溶剂(DES)分离木质素效率是实现木质纤维资源高值化利用的前提。本研究基于酸性、中性及碱性二元DES分离毛竹木质素的方法,设计三元DES以提高木质素分离效率,优化三元DES分离木质素的工艺条件,采用Kamlet-Taft溶剂化显色参数,定量分析DES的氢键性能,并对DES分离所得木质素进行结构表征。结果表明,二元DES分离木质素时,木质素溶出率由高到低依次为:酸性DES>中性DES>碱性DES,由FeCl3-聚乙二醇400-氯化胆碱构成的三元DES,其木质素溶出率较高,分离毛竹木质素的最佳工艺条件为:温度130 ℃、时间3 h、质量比1∶15、加水质量比10%(相对于聚乙二醇400质量);在此工艺条件下,木质素溶出率可达96.36%。FeCl3的引入增加了三元DES的氢键碱性,使其具有更强的氢键接受能力。拉曼光谱和傅里叶变换红外光谱分析表明,DES分离所得毛竹木质素的主要基本结构单元为愈创木基型和紫丁香基型,且结构完整性优于碱木质素。本研究结果可为DES高效清洁分离毛竹木质素提供参考。 相似文献
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为研究紫外线吸收剂对涤纶织物吸收紫外线性能的影响,将5只苯并三唑类紫外线吸收剂经分散后用高温高压浸染法使其上染到涤纶织物上,以残液法测试紫外线吸收剂对涤纶的上染率,用紫外线透过率表征织物的紫外线吸收性能.结果表明:选用的紫外线吸收剂可以在130℃下保温40~60 ming上染涤纶织物,紫外线吸收剂结构、分子质量、上染温度和用量都会影响其对涤纶的上染率,分子质量适中、芳环较多、疏水性基团比例较高的紫外线吸收剂对涤纶的上染率较高;上染率较高的紫外线吸收剂能更明显地改善涤纶织物的紫外线吸收性能,上染率不高但分子中含有2个分子内氢键螫合环的紫外线吸收剂也能明显提高涤纶织物的紫外线吸收能力. 相似文献
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本研究利用碱木质素作为生物模板诱导剂,通过水热法成功合成了一种具有良好紫外屏蔽性能的木质素/TiO_2复合纳米颗粒。结果表明,木质素/TiO_2复合纳米颗粒具有锐钛矿晶型、良好的纳米粒径和热稳定性。同时,证实了木质素的含氧官能团和TiO_2表面羟基发生类酯化反应,从而使木质素与TiO_2形成包覆嵌顿式结构的复合材料。在此基础上,研究了木质素/TiO_2复合纳米颗粒与纳米纤维素水凝胶制备薄膜材料的抗紫外性能。结果表明,添加质量分数10%的木质素/TiO_2复合纳米颗粒的纳米纤维素薄膜在全紫外线波段(200~400 nm)吸收了约90%的紫外线,表明木质素/TiO_2复合纳米颗粒具有良好的紫外屏蔽能力。 相似文献
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为获取完整的木质素化学结构,全面深刻解析木质素的结构特性,以球磨2 h的杨木为原料,通过LiCl/DMSO溶解体系溶解、再生处理,纤维素酶解,再经分离、纯化得到杨木溶解再生酶解木质素(DEL),得率和纯度分别为42.1%、39 g/kg,均高于单纯纤维素酶解木质素(CEL)。DEL分子质量较低,分散性更均一,分离过程中低分子质量的木质素更易溶出。通过碱性硝基苯氧化反应,表征了DEL的缩合程度,进一步证明了DEL为GS型木质素,且分离过程中,木质素的未缩合结构单元比例、缩合程度未发生变化。 相似文献
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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. 相似文献
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John Gilbert Catherine Simoneau David Cote Achim Boenke 《Food Additives & Contaminants》2000,17(10):889-893
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. 相似文献
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Sophie Guillot Laurence Peytavi Sylvie Bureau Renaud Boulanger Jean-Paul Lepoutre Jean Crouzet Sabine Schorr-Galindo 《Food chemistry》2006
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. 相似文献
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Jesus Simal-Gandara Miguel Sarria-Vidal Arjen Koorevaar Rinus Rijk 《Food Additives & Contaminants》2000,17(8):703-711
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. 相似文献
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M. S. Garcí a-Falc n J. Simal-G ndara S. T. Carril-Gonz lez-Barros 《Food Additives & Contaminants》2000,17(12):957-964
A simple, rapid and inexpensive method has been developed for the determination of benzo[a 相似文献
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H. J. Van Den Top A. Boenke P. A. Burdaspal J. Bustos H. P. Van Egmond T. Legarda A. Mesego A. Mourino W. E. Paulsch C. Salgado 《Food Additives & Contaminants》2001,18(9):810-824
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. 相似文献
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《肉类研究》2014,(2)
<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 相似文献
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《印刷工业》2014,(11):95-95
According to Printing and Printing Equipment Industries Association of China(PEIAC)'s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%. 相似文献
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《印刷工业》2014,(8):103-103
正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press 相似文献