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排序方式: 共有8643条查询结果,搜索用时 15 毫秒
51.
甲基异噻唑啉酮类防腐剂是一类具有高效、广谱的杀菌和抑菌性能的防腐剂,广泛应用于各类防腐领域,但该类防腐剂能否用于食品相关产品还有待研究。文章主要介绍了甲基氯异噻唑啉酮与甲基异噻唑啉酮的混合物和甲基异噻唑啉酮两类防腐剂,以及近年各国对化妆品中甲基异噻唑啉酮类防腐剂的限量要求。从调查数据看,市场上大多食品用洗涤剂都含有甲基异噻唑啉酮类防腐剂,有的含量甚至超过化妆品安全技术规范中最大允许浓度,对人体健康可能会产生较大威胁。因此,有必要对食品用洗涤剂中甲基异噻唑啉酮类防腐剂进行检测,并建议在食品用洗涤剂国家标准中列入对甲基异噻唑啉酮类防腐剂的限量。 相似文献
52.
The shear strength and aging characteristics of 63Sn–37Pb solder bumps were characterized with variation in solder ball and
UBM pad sizes. The shear strength increased with shorter effective crack size,a
effs
which was determined with the solder ball and pad sizes. The shear strength of the solder bumps on Au/Ni/Cu and Ni/Cu did
not change significantly with reflow time. Substantial decrease in the shear strength occurred for the solder bumps formed
on Au/Ni/Cu with aging treatment, and the shear strength after aging was also related to the bump shape which was determined
with the solder ball and pad sizes. 相似文献
53.
54.
塑料在包装领域有着广泛的应用,其中聚酯(PET)性能优良,应用领域不断扩大。介绍了塑料包装不断通现的新技术,以及塑料包装环保问题的几点思路。 相似文献
55.
Francis W. Maloba Michael L. Rooney Paul Wormell Minh Nguyen 《Journal of the American Oil Chemists' Society》1996,73(2):181-185
The oxidative stability of sunflower oil (SFO) was measured during storage at 23 and 37°C in the presence of a novel oxygen-scavenging
film that contained polyfuryloxirane (PFO). Commercially refined and deodorized SFO was stored in a lighted room in sealed
transparent packages containing either PFO film or an antioxidant, 0.02% butylated hydroxytoluene (BHT). Oxidative stability
was evaluated by determination of peroxide values and gas-chromatographic measurement of headspace hexanal. SFO stored in
the presence of the oxygen-scavenging film was more stable than oil stored without the film, or than film stored with 0.02%
BHT. The PFO film scavenges oxygen through energy-transfer sensitization of singlet oxygen. The film is doped with eosin and
the naturally-occurring dye, curcumin, which absorb over a wide range of visible wavelengths. Curcumin transfers its absorbed
energy to eosin, which sensitizes the production of singlet oxygen. The singlet oxygen is scavenged by PFO. The use of two
dyes increases the efficiency of the sensitization process, reducing the illumination time and intensity required for effective
oxygen scavenging. 相似文献
56.
针对工业破损检测的现状进行研究,提出运用数字图像处理系统代替传统的硬件检测。首先对薄膜进行图像预处理,运用Hough(霍夫)变换分割出连续2帧的感兴趣区域,运用小波变换增强图像对比度;其次计算各个像素点的EOI(拉普拉斯能量)和VI(对比度),将归一化处理后的值作为图像融合的系数;最后把融合后图像转化到HSI(色度、饱和度、亮度)空间,进行阈值分割,进行破损判别。实验表明,这种检测方法具有抗干扰性强、成本低、准确性高、计算量小、识别速度快的优点,基本能实现包装的实时检测。 相似文献
57.
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59.
Ceramic and Glass-Ceramic Packaging in the 1990s 总被引:22,自引:0,他引:22
Rao R. Tummala 《Journal of the American Ceramic Society》1991,74(5):895-908
A broad overview of packaging involving interconnecting, powering, protecting, and cooling semiconductor chips to meet a variety of computer system needs is presented. The general requirements for ceramics in terms of their thermal, mechanical, electrical, and dimensional control requirements are presented, both for high-performance and low-performance applications. Glass-ceramics are identified as the best candidates for high-performance systems, and aluminum nitride, alumina, or mullite are identified for low-performance systems. Glass-ceramic/copper substrate technology is discussed as an example of high-performance ceramic packaging for use in 1990s. Lower-dielectric-constant ceramics such as composites of silica, borosilicate, and cordierite, with or without polymers and porosity, are projected as potential ceramic substrate materials by the year 2000. 相似文献
60.