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美耐皿餐具中残余三聚氰胺单体向食品中的迁移行为越来越受到社会关注。合成了三聚氰胺甲醛树脂,并与不同浓度的纤维素混合,配制成的模塑料,在不同工艺条件下模压成美耐皿制件,研究了纤维素含量、模压温度、模压时间、浸泡介质和浸泡时间对美耐皿制件中残余三聚氰胺单体向介质迁移行为的影响,观察了浸泡前、后制件的表面形貌变化。结果表明,美耐皿制件中残余三聚氰胺单体向乙酸稀溶液中的迁移量最大,众多因素中纤维素含量对残余单体迁移量的影响最为显著,在浸泡300 h后达到迁移平衡,乙酸稀溶液对美耐皿制件表面存在溶解性腐蚀。 相似文献
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本文叙述了工业三聚氰胺的性质与作用。重点介绍国内外工业生产的状况,并对国内外的生产技术经济状况进行了比较,研究了我国小型三聚氰胺生产厂的现状,针对国情,指出了几条有积极意义的对策。 相似文献
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密胺塑料中三聚氰胺在食品模拟物中的迁移规律研究 总被引:1,自引:0,他引:1
采用超高效液相色谱串联质谱(UPLC-MS/MS)法,研究食品模拟物种类、接触时间、接触温度、乙酸浓度、乙醇浓度、重复使用和微波加热等迁移条件下,密胺塑料中三聚氰胺在水、4%乙酸(w/v)、10%乙醇(v/v)、95%乙醇(V/V)和异辛烷等5种食品模拟物和牛奶样品中的迁移规律。结果表明:模拟物的属性对迁移行为有显著影响,迁移量随温度的升高和时间的增加而变大。酸性食品和牛奶中的三聚氰胺迁移风险较高,且需控制密胺塑料的使用温度、盛放时间、重复使用次数及微波加热功率和时间以降低密胺塑料中三聚氰胺迁移风险。 相似文献
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本文分析了国内外三聚氰胺的市场,认为目前全世界三聚氰胺的市场已基本饱和,今后产销将相对平衡。我国三聚氰胺的生产能力已大大超出市场需求,因此,在国内发展三聚氰胺应持谨慎态度。此外,本文还针对我国现有三聚氰胺的现状,提出了令后的发展思路。 相似文献
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Yang Zhang Zhen Zhu Qi Xu Guohong Chen 《International journal of molecular sciences》2014,15(1):670-683
Primers based on the cDNA sequence of the goose growth hormone (GH) gene in GenBank were designed to amplify exon 2 of the GH gene in Huoyan goose. A total of 552 individuals were brooded in one batch and raised in Liaoning and Jiangsu Provinces, China. Single nucleotide polymorphisms (SNPs) of exon 2 in the GH gene were detected by the polymerase chain reaction (single strand conformation polymorphism method). Homozygotes were subsequently cloned, sequenced and analyzed. Two SNP mutations were detected, and 10 genotypes (referred to as AA, BB, CC, DD, AB, AC, AD, BC, BD and CD) were obtained. Allele D was predominant, and the frequencies of the 10 genotypes fit the Hardy-Weinberg equilibrium in the male, female and whole populations according to the chi-square test. Based on SNP types, the 10 genotypes were combined into three main genotypes. Multiple comparisons were carried out between different genotypes and production traits when the geese were 10 weeks old. Some indices of production performance were significantly (p < 0.05) associated with the genotype. Particularly, geese with genotype AB or BB were highly productive. Thus, these genotypes may serve as selection markers for production traits in Huoyan geese. 相似文献
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目的对水痘-带状疱疹病毒(Varicella-zoster virus,VZV)Oka株(V-Oka株)与分离于临床水痘患者的野毒株进行可变区基因序列比对分析。方法提取V-Oka株和VZV临床分离株的基因组DNA,对其串联重复序列区(R区)进行PCR扩增和测序;将R3基因的纯化产物与pMD18-T载体连接,转化感受态大肠杆菌JM109,提取质粒,经双酶切鉴定及测序;将测序结果与GenBank中登录的V-Oka株基因序列进行比对分析。结果 R1~R5基因扩增产物及R3基因重组质粒的双酶切产物片段大小均与预期相符;V-Oka株较稳定,测序结果与GenBank中登录的V-Oka株R1~R5基因序列一致,野毒株R区序列呈现多态性,与V-Oka株有差异,R4区序列区别明显。结论水痘患者的致病毒株为野毒株;R4的重复单位拷贝数可为临床快速鉴别V-Oka株与野毒株提供科学的手段。 相似文献
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酱油香精和焦糖中挥发性成分分析 总被引:1,自引:0,他引:1
用顶空固相微萃取-气质联用技术和内标物定量方法,对酱油香精和焦糖中的挥发性成分进行了分析,筛选出了二者的特征挥发性组分,以此判断酱油样品中是否添加了酱油香精和焦糖。5个香精样品共分析出56种挥发性组分,其中有14个组分为5个样品所共有,可作为酱油中酱油香精存在的特征提示物的有乙酰丙酸乙酯、乙酸苯乙酯和甲基环戊烯醇酮,其峰面积与内标物(2-辛醇,1mg/L)峰面积的比值依次为0.0857、0.2431和2.2408。3个焦糖样品共分析出21种挥发性组分,其中有6个组分为3个样品所共有,可作为酱油中焦糖存在的特征提示物的有5-甲基-2-呋喃甲醛和5-甲基-2-乙酰基呋喃,其峰面积与内标物峰面积的比值依次为0.7669和0.1094。 相似文献
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碳纳米管预处理方法对天然橡胶/纯化碳纳米管复合材料力学性能的影响 总被引:1,自引:0,他引:1
纯化后的碳纳米管(CNT)分别经过球磨、表面活性剂十二烷基苯磺酸钠或分散-黏合体系预处理,再与100份(质量)天然橡胶(NR)混炼,可制备NR/纯化CNT复合材料。结果表明,纯化CNT直接与NR混炼,前者在NR中的分散效果不好,二者的界面结合欠佳。纯化CNT经球磨后,团聚程度增加,对复合材料力学性能影响不大。经表面活性剂十二烷基苯磺酸钠处理后的纯化CNT,内聚能下降,用差示扫描量热法(DSC)测定复合材料的DSC曲线表明,复合材料的结晶熔融峰面积增大,力学性能降低。用分散-黏合体系处理纯化CNT,可同时提高纯化CNT在橡胶中的分散效果及界面黏合性,试样结晶熔融峰变得不明显,因此该复合材料的邵尔A型硬度提高,拉伸强度、300%定伸应力和撕裂强度等优于其他试样。 相似文献
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Bio-based nanocomposite latexes were prepared by emulsification–diffusion method. Two kinds of silicate, sodium and organo-modified montmorillonites, were compared and clay concentrations were varied at 1–6 wt%. The resultant particles were characterized in terms of particle size, particle morphology, and zeta potential. Silicate dispersion in the polymer matrix was evaluated by X-ray diffractometry and transmission electron microscopy, while thermal properties of the resultant nanocomposite films were also investigated by differential scanning calorimetry and thermogravimetry. The average particle sizes of the emulsions were found in the range of 20–30 μm, whereas zeta potentials of the particles were obtained in the range from −37 to −60 mV, depending on the silicate type and content. X-ray diffraction patterns combined with micrographs indicated that the silicates were effectively distributed in the polymer matrix where extensive exfoliation and partial intercalation were present. Thermal properties of the nanocomposite films were significantly improved compared to those of the unfilled film. Thermal stability tended to increase in accordance with clay content for both types of silicate, in which the highest shift of degradation temperature was obtained with the sodium montmorillonite filled nanocomposite film at the maximum loading content (6 wt%). 相似文献