In order to investigate the effect of space environmental factors on spacecraft materials, a ground-based simulation facility for space atomic oxygen（AO） irradiation was developed in our laboratory. Some Kapton film...In order to investigate the effect of space environmental factors on spacecraft materials, a ground-based simulation facility for space atomic oxygen（AO） irradiation was developed in our laboratory. Some Kapton film samples were subjected to AO beam generated by this facility. The Kapton films before and after AO exposure were analyzed comparatively using optical microscopy, scanning electronic microscopy, atomic force microscopy, high-precision microbalance, and X-ray photoelectron spectroscopy. The experimental results indicate that the transmittance of Kapton film will be reduced by AO irradiation notably, and its color deepens from pale yellow to brown. Surface roughness of the AO-treated sample is already increased obviously after AO irradiation for 5 hours, and exhibits a flannel-like appearance after 15 hours’ exposure in AO beam. The imide rings and benzene rings in kapton molecule are partially decomposed, and some new bonds form during AO irradiation. The mass loss of kapton film increases linearly with the increase of AO fluence, which is resulted from the formation of volatile products, such as CO, CO2 and NOx. The breakage in structure and degradation in properties of AO-treated Kapton film can be attributed to the integrated effect ofimpaction and oxidization of AO beam. The test results agree well with the space flight experimental data.展开更多
This study aimed to control printing ambient temperature and oxygen content collaboratively to achieve synchronous improvement of the sensory and nutritional quality of printed products.In this study,spinach juice and...This study aimed to control printing ambient temperature and oxygen content collaboratively to achieve synchronous improvement of the sensory and nutritional quality of printed products.In this study,spinach juice and potato snowflake powder were used as raw materials to prepare printing materials.The results showed that the printing material with a 20%addition of potato snowflake powder had the best printing performance.Enhancing the flavor of the printed products in the printing process by increasing the printing ambient temperature,the printed product with better flavor quality was obtained at 40℃.However,the increase in ambient temperature had adverse effects on the color and antioxidant capacity of the printed product,the ΔE value of the printed product at 40℃ was 6.18±0.64.Based on this ambient temperature,reducing the oxygen content in the printing environment inhibited the adverse effects of rising temperature on the color and antioxidant capacity of printed products.When the oxygen content was below 1%,the printed product maintained the color and antioxidant capacity before printing,the ΔE value of the printed product was only 0.95±0.09,and there was no significant difference in antioxidant properties(total chlorophyll content,total carotenoid content,total phenolic content,free radical scavenging activity).Therefore,while successfully improving the flavor of the product,this study achieved the maintenance of color,antioxidant capacity,and other qualities,which is an effective exploration of using 3D printing technology to produce high-quality food.展开更多
基金Funded by the Distinguished Young Scholars of NSFC(51125023)the Major State Basic Research Development Programof China(2011CB013405)the Natural Science Foundation of Beijing City(3120001)
文摘In order to investigate the effect of space environmental factors on spacecraft materials, a ground-based simulation facility for space atomic oxygen（AO） irradiation was developed in our laboratory. Some Kapton film samples were subjected to AO beam generated by this facility. The Kapton films before and after AO exposure were analyzed comparatively using optical microscopy, scanning electronic microscopy, atomic force microscopy, high-precision microbalance, and X-ray photoelectron spectroscopy. The experimental results indicate that the transmittance of Kapton film will be reduced by AO irradiation notably, and its color deepens from pale yellow to brown. Surface roughness of the AO-treated sample is already increased obviously after AO irradiation for 5 hours, and exhibits a flannel-like appearance after 15 hours’ exposure in AO beam. The imide rings and benzene rings in kapton molecule are partially decomposed, and some new bonds form during AO irradiation. The mass loss of kapton film increases linearly with the increase of AO fluence, which is resulted from the formation of volatile products, such as CO, CO2 and NOx. The breakage in structure and degradation in properties of AO-treated Kapton film can be attributed to the integrated effect ofimpaction and oxidization of AO beam. The test results agree well with the space flight experimental data.
基金supported by the National Key R&D Program of China(No.2022YFF1101700)National Natural Science Foundation Program of China(No.31872902)Jiangsu Province(China)“Collaborative Innovation Center for Food Safety and Quality Control”Industry Development Program,Jiangsu Province Key Laboratory Project of Advanced Food Manufacturing Equipment and Technology(No.FMZ202003)。
文摘This study aimed to control printing ambient temperature and oxygen content collaboratively to achieve synchronous improvement of the sensory and nutritional quality of printed products.In this study,spinach juice and potato snowflake powder were used as raw materials to prepare printing materials.The results showed that the printing material with a 20%addition of potato snowflake powder had the best printing performance.Enhancing the flavor of the printed products in the printing process by increasing the printing ambient temperature,the printed product with better flavor quality was obtained at 40℃.However,the increase in ambient temperature had adverse effects on the color and antioxidant capacity of the printed product,the ΔE value of the printed product at 40℃ was 6.18±0.64.Based on this ambient temperature,reducing the oxygen content in the printing environment inhibited the adverse effects of rising temperature on the color and antioxidant capacity of printed products.When the oxygen content was below 1%,the printed product maintained the color and antioxidant capacity before printing,the ΔE value of the printed product was only 0.95±0.09,and there was no significant difference in antioxidant properties(total chlorophyll content,total carotenoid content,total phenolic content,free radical scavenging activity).Therefore,while successfully improving the flavor of the product,this study achieved the maintenance of color,antioxidant capacity,and other qualities,which is an effective exploration of using 3D printing technology to produce high-quality food.
