在实验温度为900-1200℃，应变率为0.001-1 s-1的条件下，对Fe-29Ni-17Co合金进行热压缩试验。热压缩过程中的动态再结晶导致材料的流变软化。用双曲正弦方程分析材料的流变行为，并确定了相应的材料常数A, n 和α，其中得到的表观活化...在实验温度为900-1200℃，应变率为0.001-1 s-1的条件下，对Fe-29Ni-17Co合金进行热压缩试验。热压缩过程中的动态再结晶导致材料的流变软化。用双曲正弦方程分析材料的流变行为，并确定了相应的材料常数A, n 和α，其中得到的表观活化能为423 kJ/mol。材料的应力峰值与稳态应力对Zener-Hollomon参数显示出简单的指数依赖关系。用Avrami方程分析了动态再结晶动力学，得到相应的指数为2.7，高于文献报道的2，这与连续动态再结晶机制有关。采用Cingara方程搭建峰值流变曲线，得到应变指数c约为0.85，比有关报道的不锈钢的c值0.2高，这点更加强了关于进行Fe-29Ni-17Co合金动态回复或连续动态再结晶研究的想法。展开更多
Carotenoids are indispensable to plants and critical in human diets. Plastids are the organelles for carotenoid biosynthesis and storage in plant cells. They exist in various types, which include proplastids, etioplas...Carotenoids are indispensable to plants and critical in human diets. Plastids are the organelles for carotenoid biosynthesis and storage in plant cells. They exist in various types, which include proplastids, etioplasts, chloroplasts, amyloplasts, and chromoplasts. These plastids have dramatic differences in their capacity to synthesize and sequester carotenoids. Clearly, plastids play a central role in governing carotenogenic activity, carotenoid stability, and pigment diversity. Understanding of carotenoid metabolism and accumulation in various plastids expands our view on the multifaceted regulation of carotenogenesis and facilitates our efforts toward developing nutrient-enriched food crops. In this review, we provide a comprehensive overview of the impact of various types of plastids on carotenoid biosynthesis and accumulation, and discuss recent advances in our understanding of the regulatory control of carotenogenesis and metabolic engineering of carotenoids in light of plastid types in plants.展开更多
文摘在实验温度为900-1200℃，应变率为0.001-1 s-1的条件下，对Fe-29Ni-17Co合金进行热压缩试验。热压缩过程中的动态再结晶导致材料的流变软化。用双曲正弦方程分析材料的流变行为，并确定了相应的材料常数A, n 和α，其中得到的表观活化能为423 kJ/mol。材料的应力峰值与稳态应力对Zener-Hollomon参数显示出简单的指数依赖关系。用Avrami方程分析了动态再结晶动力学，得到相应的指数为2.7，高于文献报道的2，这与连续动态再结晶机制有关。采用Cingara方程搭建峰值流变曲线，得到应变指数c约为0.85，比有关报道的不锈钢的c值0.2高，这点更加强了关于进行Fe-29Ni-17Co合金动态回复或连续动态再结晶研究的想法。
文摘Carotenoids are indispensable to plants and critical in human diets. Plastids are the organelles for carotenoid biosynthesis and storage in plant cells. They exist in various types, which include proplastids, etioplasts, chloroplasts, amyloplasts, and chromoplasts. These plastids have dramatic differences in their capacity to synthesize and sequester carotenoids. Clearly, plastids play a central role in governing carotenogenic activity, carotenoid stability, and pigment diversity. Understanding of carotenoid metabolism and accumulation in various plastids expands our view on the multifaceted regulation of carotenogenesis and facilitates our efforts toward developing nutrient-enriched food crops. In this review, we provide a comprehensive overview of the impact of various types of plastids on carotenoid biosynthesis and accumulation, and discuss recent advances in our understanding of the regulatory control of carotenogenesis and metabolic engineering of carotenoids in light of plastid types in plants.
