共查询到19条相似文献,搜索用时 78 毫秒
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食用色素是重要的食品添加剂之一,它能使食品具有鲜艳的色泽。食品的色、味、香是食品加工中的重要问题,食品具有鲜艳的色泽,对增进食欲有一定的促进作用。许多食品在加工生产过程中,原有的色泽容易发生褪色或变色。为了改善食品的色泽,提高竞争力,在加工生产过程中往往使用食用色素进行着色。食用色素按其来源可分为两大类,即人工利用化学方法合成的色素和由天然动、植物中提取的天然食用色素。人工合成色素虽然具有鲜艳的色泽,优良的染着色和调色性,但人工合成色素多以煤焦油为原料,原料本身就具有一定毒性,且在合成过程中容易受铅、砷以及 相似文献
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甲醛是致癌、致畸物质,世界各国均严禁将甲醛及其化合物用作食品添加剂,食品中的甲醛问题成为世界公共卫生系统关注的焦点,研究食品中甲醛的快速检测方法对保障消费者的健康以及维护公共卫生安全具有重要意义,本文对海产品及水发食品中甲醛的快速检测分析方法研究进展进行综述,以期对同行开展相关研究有所帮助。 相似文献
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超临界CO2萃取柑橘精油的工艺研究 总被引:1,自引:0,他引:1
以柑橘皮为实验材料,以柑橘精油萃取率为指标,用超临界二氧化碳萃取方法,在萃取温度、萃取压力、萃取时间、投料量试验的基础上,经正交试验对柑橘皮中精油的萃取工艺条件进行了优化。研究发现柑橘皮中精油超临界二氧化碳萃取的最佳萃取工艺条件为压力30 MPa,温度32℃,投料量120 g,萃取时间2.5 h,柑橘精油的萃取率为3.60%。 相似文献
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John J. Steencken 《Journal of the American Ceramic Society》1947,30(2):64-68
The effects of spraying techniques on orange-peel surface of porcelain enamel were studied. The volume of atomizing air per unit volume of atomized slip is the predominating factor, and the ratio appears to be 1000 to 1200 cc. of air per 1.0 cc. of slip for average conditions. The angle of incidence should be 60 degrees or more. The minimum fluid and atomizing pressures should be adjusted to suit the specific gun nozzle and tip but should maintain the air-to-slip ratio indicated. The following conclusions are given: (1) The type of fluid nozzle of the spray gun alone does not appreciably affect orange peel; (2) the type of air cap and its air capacity affects orange peel definitely; the tip with the largest number of orifices and greatest air capacity offers much better atomization and smoother spray, and there is a definite indication that the fineness and degree of atomization is a measure of the amount of orange peel that may be expected; (3) lowering the atomizing pressure increases the tendency toward orange peel; (4) increasing the rate of flow of the enamel through the spray gun increases the tendency toward orange peel; (5) closer spraying distances increase the tendency toward orange peel; (6) decreasing the angle of incidence of the spray increases the tendency toward orange peel; (7) a round, concentrated spray has a greater tendency toward orange peel than the wide flat spray fan; (8) increasing the application weight increases the tendency toward orange peel although good results could be obtained up to 50 to 55 gm. per sq. ft. in one coat; (9) decreasing the specific gravity of the enamel slip increases the tendency toward orange peel; the best specific gravities for spraying cover-coat enamels are above 1.80; and (10) the viscosity of the enamel slip does not appreciably affect the orange-peel tendencies of the enamel, but there is a definite indication that the best results are obtained with the higher viscosities. 相似文献
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主要从面漆前的底层控制、油漆材料施工参数控制、机器人仿型及参数控制和油漆更新率等方面对轿车车身油漆橘皮的影响和油漆橘皮的解决方法进行了研究和实践,为轿车橘皮问题的控制提供一些参考。 相似文献
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以表面化学的观点浅析涂膜内物料流动引起表面张力梯度的出现是产生汽车面漆桔皮缺陷的根本原因;提出了解决漆膜桔皮缺陷需要从材料、工艺、设备着手,并重点指出手工喷涂中排除桔皮的方法。 相似文献
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Computer rendering and visual detection of orange peel 总被引:1,自引:0,他引:1
The computer graphic simulation of a common spray painting artifact, called orange peel, is discussed. Orange peel distorts
surface reflections and is commonplace in product design applications. The orange peel measurements from a standard industrial
instrument are used to construct a height field, and this surface is rendered using traditional normal mapping techniques.
Comparisons are made between real panels with orange peel and simulations of those panels. A simple visual model for detecting
the presence of orange peel is also presented and evaluated. User testing of the model confirms that orange peel is more visible
on dark paint colors than on light paint colors. The latter outcome suggests that to minimize application time, but still
keep orange peel below visual threshold, paint application systems should be designed to take paint color into account. 相似文献
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在乘用车的车身涂装中,涂层橘皮是最常见和难以控制的缺陷之一,已成为汽车厂家的棘手问题。阐述了影响涂膜流动和外观的因素;介绍了涂层外观漆膜橘皮的检测方法和车身漆膜橘皮的成因及其防治;以及乘用车塑料外饰件涂装受橘皮的影响因素及其控制;同时指出了车身漆膜橘皮的预防措施。 相似文献