Evidence of gene conversion in the evolutionary process of the codon 41/42 (-CTTT) mutation causing beta-thalassemia in southern China

The 4-bp deletion (-CTTT) at codon 41/42 (CD41/42) of the human beta-globin gene represents one of the most common beta-thalassemia mutations in East Asia and Southeast Asia, which is historically afflicted with endemic malaria, thus hypothetically evolvi

快速热处理对应变InGaAs/GaAs单量子阱激光二极管电子发射和DX中心的影响

研究分子束外延（MBE）生长的应变In_(0.2)Ga_(0.8)As/GaAs折射率梯度变化异质结单量子阱激光二极管的快速热处理（RTA）效应。结果表明，RTA移除了InCaAs/GaAs界面非辐射中心，提高77K光致发光效率和有源层电子发射。同时Al和Ga原子互扩散，也增加了AlGaAs波导层DX中心浓度。RTA处理后样品电流冲击老化实验证明DX中心浓度呈现出相应的增加。这表明DX中心可能是激光二极管性能退化的原因之一。