共查询到20条相似文献,搜索用时 109 毫秒
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目的 综述目前食品接触材料中几种常用材料(纸、塑料、油墨)迁移与检测的研究进展,并指出几种材料未来的发展趋势,促使我国食品行业向着更绿色、更安全的方向发展。方法 概述纸质、塑料、油墨的发展趋势和材料中有害物质的来源;对比几种材料的迁移规律及迁移模型;总结几类常见有害物质的检测方法。结论 绿色环保的生物基材料是食品接触材料未来的发展方向,同时也需重视可持续性生物基食品接触材料的化学安全性。因其产生的化学品对人体健康的影响不甚明朗,因此需多方面研究生物基食品接触材料中化学物质的存在和迁移到食品中的情况,并采取相应措施减少包装材料的使用,降低材料中有毒有害物质对人体和环境的威胁。 相似文献
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目的 介绍抗菌剂在塑料包装中的应用及国内外的研究进展,阐述抗菌剂在改善包装材料抗菌性能方面的作用机理及优缺点,并重点关注抗菌剂在塑料包装材料领域中的安全性评估。方法 总结国内外抗菌剂在塑料包装材料领域的研究现状,简单介绍抗菌剂分类和抗菌塑料的制备方法,并重点整理分析抗菌剂在塑料包装材料领域的应用和进展,讨论塑料中抗菌剂在安全方面的问题。结果 虽然塑料包装中的抗菌剂能够提高包装材料的抗菌性能,但同时也可能在与食品接触的过程中迁移到食品中;对抗菌塑料中抗菌成分的迁移机理进行了深入研究,有助于人们认识食品接触材料的安全性和更好地发展食品接触材料。结论 抗菌塑料包装在应用中既要为包装材料提供抗菌性,还需要保证其安全性。 相似文献
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A method is proposed for estimating the parameters of a mixture of exponential and Weibull distributions for which the accuracy of preliminary estimates obtained by graphical analysis is refined in accordance with the criterion of maximum likelihood. The efficiency of the proposed method is supported by the results of statistical modeling. 相似文献
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O'Brien RS 《Radiation protection dosimetry》2003,105(1-4):95-100
Australia has several uranium mines and a large number of mineral sand mines, with associated processing facilities. Exposures resulting from these mining and processing operations usually involve intakes of mixtures of radionuclides. This work describes the development of a suite of first order, linear compartment models, based on the ICRP Publication 66 respiratory tract model, and an analytical solution to the decay equations, for assessing the consequences of such intakes. The computer programs based on these models directly compute excretion, organ retention and organ and whole-body doses for intakes of either single radionuclides or any mixture of radionuclides belonging to the same radioactive decay chain. The intake can be via inhalation, ingestion or injection, and can be acute, chronic or of limited duration. The starting concentration and degree of secular (dis)equilibrium can be specified for each radionuclide. No assumptions need to be made about the relative magnitudes of the radioactive half-lives of the different nuclides. 相似文献
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本文根据多年的实践检定经验 ,参照JJF1 0 59- 1 999《测量不确定度评定与表示》以及《测量不确定度表达 1 0讲》 ,对卧式金属罐容量的测量结果不确定度进行了评定。 相似文献
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An approximate analytical expression is derived for the velocity of the front of the wave of change of boiling modes on a
rod and on a plate. The impact of the Thomson effect and of the heater orientation in the gravity field is included. Adequate
agreement is demonstrated between the derived relations and experimental data. 相似文献
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Liebert A Wabnitz H Grosenick D Möller M Macdonald R Rinneberg H 《Applied optics》2003,42(28):5785-5792
A novel method for the determination of the optical properties of tissue from time-domain measurements is presented. The data analysis is based on the evaluation of the first moment and the second centralized moment, i.e., the mean time of flight and the variance of the measured distribution of times of flight (DTOF) of photons injected by short (picosecond) laser pulses. Analytical expressions are derived for calculation of absorption and of reduced scattering coefficients from these moments by application of diffusion theory for infinite and semi-infinite homogeneous media. The proposed method was tested on experimental data obtained with phantoms, and results for absorption and reduced scattering coefficients obtained by the proposed method are compared with those obtained by fitting of the same data with analytical solutions of the diffusion equation. Furthermore, the accuracy of the moment analysis was investigated for a range of integration limits of the DTOF. The moment analysis may serve as a comparatively fast method for evaluating optical properties with sufficient accuracy and can be used, e.g., for on-line monitoring of optical properties of biological tissue. 相似文献
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V. T. Bublik A. I. Voronin E. A. Vygovskaya V. F. Ponomarev N. Yu. Tabachkova O. V. Toropova 《Inorganic Materials》2011,47(14):1563-1568
An analysis of anisotropy of the properties of a Bi2Se0.3Te2.7 solid solution was carried out using construction of demonstrative surfaces for thermoelectric effectiveness and thermal
expansion coefficients. It is shown that the texture is an important factor forming anisotropy of properties and technological
fitness of ingots for manufacturing modules. Anisotropy of properties based on the studies of the ingot textures obtained
using the float-zone method and Bridgman method (growing thermoelectric plates in a flat cavity) was studied. 相似文献