改进的测定方法依照国标(韦氏法)测定油脂碘值原理与操作方法,在加入韦氏试剂后,加入10 mL 3%醋酸镁溶液作催化剂,反应时间为13 min。结果表明:两种方法测定结果基本一致,相对误差小于2%,说明加入醋酸镁催化剂对测定结果的准确度没有产...改进的测定方法依照国标(韦氏法)测定油脂碘值原理与操作方法,在加入韦氏试剂后,加入10 mL 3%醋酸镁溶液作催化剂,反应时间为13 min。结果表明:两种方法测定结果基本一致,相对误差小于2%,说明加入醋酸镁催化剂对测定结果的准确度没有产生不良影响。本改进方法准确可靠,且毒性小,是一种测定油脂碘值的快速韦氏法。展开更多
Using a simple multifractal model based on the model De Wijs, various geochemical map patterns for element concentration values are being simulated. Each pattern is self-similar on the average in that a similar patter...Using a simple multifractal model based on the model De Wijs, various geochemical map patterns for element concentration values are being simulated. Each pattern is self-similar on the average in that a similar pattern can be derived by application of the multiplicative cascade model used to any small subarea on the pattern. In other experiments, the original, self-similar pattern is distorted by superimposing a 2-dimensional trend pattern and by mixing it with a constant concentration value model. It is investigated how such distortions change the multifractal spectrum estimated by means of the 3-step method of moments. Discrete and continuous frequency distribution models are derived for patterns that satisfy the model of De Wijs. These simulated patterns satisfy a discrete frequency distribution model that as upper bound has a continuous frequency distribution to which it approaches in form when the subdivisions of the multiplicative cascade model are repeated indefinitely. This limiting distribution is lognormal in the center and has Pareto tails. Potentially, this approach has important implications in mineral and oil resource evaluation.展开更多
A smartphone camera-based colorimetric method is developed for the determination of iodine value of vegetable oils.The small amount of Wijs reagent is employed for halogenation of the unsaturated sites of the sample.T...A smartphone camera-based colorimetric method is developed for the determination of iodine value of vegetable oils.The small amount of Wijs reagent is employed for halogenation of the unsaturated sites of the sample.The rest of unreacted reagent is transformed into iodine,which further reacts with the starch solution to form the blue color complex.The free download smartphone application is used for measuring the blue color intensity.More than one sample can be measured by taking only one photo shot.Under the controlled illuminance,the calibration graph for measuring the iodine values of various vegetable oils is constructed from the dissolved triiodide.The detection and quantitation limits are less than 0.02 and 0.032 mM I;,respectively.This method provides a better determination result of the iodine value compared with the standard titrimetric method.This method is convenient,simple,rapid,inexpensive,and easy operation with few chemical waste products.展开更多
文摘改进的测定方法依照国标(韦氏法)测定油脂碘值原理与操作方法,在加入韦氏试剂后,加入10 mL 3%醋酸镁溶液作催化剂,反应时间为13 min。结果表明:两种方法测定结果基本一致,相对误差小于2%,说明加入醋酸镁催化剂对测定结果的准确度没有产生不良影响。本改进方法准确可靠,且毒性小,是一种测定油脂碘值的快速韦氏法。
文摘Using a simple multifractal model based on the model De Wijs, various geochemical map patterns for element concentration values are being simulated. Each pattern is self-similar on the average in that a similar pattern can be derived by application of the multiplicative cascade model used to any small subarea on the pattern. In other experiments, the original, self-similar pattern is distorted by superimposing a 2-dimensional trend pattern and by mixing it with a constant concentration value model. It is investigated how such distortions change the multifractal spectrum estimated by means of the 3-step method of moments. Discrete and continuous frequency distribution models are derived for patterns that satisfy the model of De Wijs. These simulated patterns satisfy a discrete frequency distribution model that as upper bound has a continuous frequency distribution to which it approaches in form when the subdivisions of the multiplicative cascade model are repeated indefinitely. This limiting distribution is lognormal in the center and has Pareto tails. Potentially, this approach has important implications in mineral and oil resource evaluation.
基金financially supported by the research fund of Rambhai Barni Rajabhat Universitythe Faculty of Science and Technology,Rambhai Barni Rajabhat University for partial supported。
文摘A smartphone camera-based colorimetric method is developed for the determination of iodine value of vegetable oils.The small amount of Wijs reagent is employed for halogenation of the unsaturated sites of the sample.The rest of unreacted reagent is transformed into iodine,which further reacts with the starch solution to form the blue color complex.The free download smartphone application is used for measuring the blue color intensity.More than one sample can be measured by taking only one photo shot.Under the controlled illuminance,the calibration graph for measuring the iodine values of various vegetable oils is constructed from the dissolved triiodide.The detection and quantitation limits are less than 0.02 and 0.032 mM I;,respectively.This method provides a better determination result of the iodine value compared with the standard titrimetric method.This method is convenient,simple,rapid,inexpensive,and easy operation with few chemical waste products.
