The yellowness of new processed down duvet after exposure to light irradiation seems very mysterious,degree of its yellowness sometimes minor,other times serious,seemingly erratic.So it is very essential for down duve...The yellowness of new processed down duvet after exposure to light irradiation seems very mysterious,degree of its yellowness sometimes minor,other times serious,seemingly erratic.So it is very essential for down duvet manufacturers to figure out the cause of this problem.The yellowed down duvet was split into two parts firstly,one was the external fabric which treated with antidrilling finish of polyurethane(PU) in advance,the other was filled down.Results showed that yellowing of external fabric was serious while the filled down yellowness was not obvious.However,when the external fabric and the filled down from the same batch of duvet were irradiated under the same condition respectively,the result indicated both the external fabric and the filled down had not yellowed as the above duvet.Therefore,it was inferred that the external fabric's yellowing was possibly induced by one property of the filled down.Then the key performance indicators of the filled down,such as cleanliness,oxygen consumption,and microorganisms,were measured and analyzed,and the extraction liquid of the down was also analyzed by the chromogenic reaction and UV-vis spectra.Results indicated the non-decomposed hydrogen peroxide residued in the filled down which would cause a higher oxygen consumption and induce photo oxidation yellowing of the PU film on external fabric,and the degree of its yellowing increased with the concentration of residual hydrogen peroxide increasing.Hydrogen peroxide composition would speed up the photo oxidation yellowing process and decrease the IR transmittance of PU film.Meanwhile its yellowed degree aggravating.展开更多
The purpose of the investigation was to create a new gold alloy of yellow for casting the frames of metal ceramic dentures. The yellow color corresponds to the consumer and aesthetic needs of some patients, because it...The purpose of the investigation was to create a new gold alloy of yellow for casting the frames of metal ceramic dentures. The yellow color corresponds to the consumer and aesthetic needs of some patients, because it is a sign of the metal, which is noble and innocuous. The main alloying elements of the majority of gold alloys for metal-ceramics are platinum and palladium, which increase the strength characteristics. Copper, tin, and other precious metals and base metals are also introduced in these alloys. At the same time, it is necessary to ensure the correspondence of the properties of the alloy with those of the ceramics applied onto the metal frame. For this purpose, the thermal expansion coefficient of the alloy (TEC) should be in a range of 13.5~14.5 ×10 6 K 1 when heated from 20 to 600 ℃ . The two-component alloys, alloying of gold with platinum and palladium results in a decrease in the TEC, and the introduction of copper, silver, and tin, increases it. Multidirectional influence of the alloying elements is a factor in achieving compliance of the TEC with the given values of the alloy. In multicomponent systems, however, the mutual influence of individual components on the properties of the alloy is unpredictable. This also applies to the color characteristics of the alloys, which vary in the direction of reducing the yellowness with increasing concentration of platinum and palladium, while other elements may have the opposite effect on the results. Yellowness index (YI), calculated according to the results of spectrophotometric studies, has been chosen as an objective indicator of color. In this study, the requirement for YI was given not less than 25; the color of such alloys can be called light yellow. All the alloys investigated contained 85% (by weight) of gold. Therefore, higher corrosion resistance and biological inertness of a finished dental products were ensured. Among the alloys that met the yellowness/TEC requirements, two alloys have been selected that were 'most yellow' (PLAGODENT-PLUS展开更多
130 wheat varieties are selected as materials to test the LOX activity, whiteness, yellowness, carotenoids content and RVA parameters, which are to be analyzed by variance analysis, correlation analysis, cluster analy...130 wheat varieties are selected as materials to test the LOX activity, whiteness, yellowness, carotenoids content and RVA parameters, which are to be analyzed by variance analysis, correlation analysis, cluster analysis and classified according to the origins. The result shows there are highly significant variations in LOX activity from varieties; LOX activity is positively correlated with whiteness, and significantly and negatively correlated with yellowness. Cluster analysis applying longest distance method based on LOX activity clusters all the varieties or lines into three major groups. There are great differences between the averages of LOX activity from varieties. LOX activities are discussed in the application of nutritional quality improvement in wheat.展开更多
基金National Natural Science Foundation of China(No.51503002)Nature Science Foundation of Anhui Province,China(No.1608085QB43)Natural Science Fund of Education Department of Anhui Province,China(No.KJ2016A796)
文摘The yellowness of new processed down duvet after exposure to light irradiation seems very mysterious,degree of its yellowness sometimes minor,other times serious,seemingly erratic.So it is very essential for down duvet manufacturers to figure out the cause of this problem.The yellowed down duvet was split into two parts firstly,one was the external fabric which treated with antidrilling finish of polyurethane(PU) in advance,the other was filled down.Results showed that yellowing of external fabric was serious while the filled down yellowness was not obvious.However,when the external fabric and the filled down from the same batch of duvet were irradiated under the same condition respectively,the result indicated both the external fabric and the filled down had not yellowed as the above duvet.Therefore,it was inferred that the external fabric's yellowing was possibly induced by one property of the filled down.Then the key performance indicators of the filled down,such as cleanliness,oxygen consumption,and microorganisms,were measured and analyzed,and the extraction liquid of the down was also analyzed by the chromogenic reaction and UV-vis spectra.Results indicated the non-decomposed hydrogen peroxide residued in the filled down which would cause a higher oxygen consumption and induce photo oxidation yellowing of the PU film on external fabric,and the degree of its yellowing increased with the concentration of residual hydrogen peroxide increasing.Hydrogen peroxide composition would speed up the photo oxidation yellowing process and decrease the IR transmittance of PU film.Meanwhile its yellowed degree aggravating.
文摘The purpose of the investigation was to create a new gold alloy of yellow for casting the frames of metal ceramic dentures. The yellow color corresponds to the consumer and aesthetic needs of some patients, because it is a sign of the metal, which is noble and innocuous. The main alloying elements of the majority of gold alloys for metal-ceramics are platinum and palladium, which increase the strength characteristics. Copper, tin, and other precious metals and base metals are also introduced in these alloys. At the same time, it is necessary to ensure the correspondence of the properties of the alloy with those of the ceramics applied onto the metal frame. For this purpose, the thermal expansion coefficient of the alloy (TEC) should be in a range of 13.5~14.5 ×10 6 K 1 when heated from 20 to 600 ℃ . The two-component alloys, alloying of gold with platinum and palladium results in a decrease in the TEC, and the introduction of copper, silver, and tin, increases it. Multidirectional influence of the alloying elements is a factor in achieving compliance of the TEC with the given values of the alloy. In multicomponent systems, however, the mutual influence of individual components on the properties of the alloy is unpredictable. This also applies to the color characteristics of the alloys, which vary in the direction of reducing the yellowness with increasing concentration of platinum and palladium, while other elements may have the opposite effect on the results. Yellowness index (YI), calculated according to the results of spectrophotometric studies, has been chosen as an objective indicator of color. In this study, the requirement for YI was given not less than 25; the color of such alloys can be called light yellow. All the alloys investigated contained 85% (by weight) of gold. Therefore, higher corrosion resistance and biological inertness of a finished dental products were ensured. Among the alloys that met the yellowness/TEC requirements, two alloys have been selected that were 'most yellow' (PLAGODENT-PLUS
基金Supported by the National Natural Science Foundation of China(NO:31371615)National Key Research&Developing Plan(2016YFD0300405)the National Natural Science Foundation of Anhui Province(1608085MC70)~~
文摘130 wheat varieties are selected as materials to test the LOX activity, whiteness, yellowness, carotenoids content and RVA parameters, which are to be analyzed by variance analysis, correlation analysis, cluster analysis and classified according to the origins. The result shows there are highly significant variations in LOX activity from varieties; LOX activity is positively correlated with whiteness, and significantly and negatively correlated with yellowness. Cluster analysis applying longest distance method based on LOX activity clusters all the varieties or lines into three major groups. There are great differences between the averages of LOX activity from varieties. LOX activities are discussed in the application of nutritional quality improvement in wheat.
