Desorption and Ripening of Low Density InAs Quantum Dots

In this paper, combining low deposition rate with proper growth temperature, we have developed a way to prepare very low-density quantum dots (QDs) suited for the study of single OD properties without resorting to submicron lithography. Experiment results demonstrate that InAs desorption is significant during growing the low density QDs. Ripening of InAs QDs is clearly observed during the post-growth annealing. Photoluminescence spectroscopy reveals that the emission wavelength of low density InAs QDs arrives at 1332.4 nm with a GaAs capping layer.

8 mu m strain-compensated quantum cascade laser operating at room temperature

We report on the material growth and device performance characterization of a strain-compensated In0.54Ga0.46As/In0.51Al0.49As quantum cascade laser at lambda similar to 8 mu m. For 2 mu s pulse at a 5 kHz repetition rate, laser action is achieved up to room temperature (30 degrees C). The tuning coefficient d lambda/dT is 1.37 nm K-1 between 83 K and 163 K and 0.60 nm K-1 in the range from 183 K to 303 K. The peak output power is reported to be similar to 11.3 mW per facet at 293 K and the corresponding threshold current density is 5.69 kA cm(-2).

Desorption and Ripening of Low Density InAs Quantum Dots

In this paper, combining low deposition rate with proper growth temperature, we have developed a way to prepare very low-density quantum dots (QDs) suited for the study of single OD properties without resorting to submicron lithography. Experiment results demonstrate that InAs desorption is significant during growing the low density QDs. Ripening of InAs QDs is clearly observed during the post-growth annealing. Photoluminescence spectroscopy reveals that the emission wavelength of low density InAs QDs arrives at 1332.4 nm with a GaAs capping layer.

慢正电子对ZnO中本征缺陷的研究

利用慢正电子研究了不同氧含量时射频磁控反应溅射制备的ZnO样品,观察到ZnO中本征缺陷（Vo,VZn）随混合气体中O2比例（PO2）的变化关系.结果表明

一种快前置放大电路的研制

简要介绍了研制的快前置放大电路,该电路是一个完全的直流放大器,具有较高的电压增益(Ar≥900),较快的上升沿(tr≤4ns),低噪声(等效输入噪声电压VN≤14μV),电路中引入贝塞尔滤波电路和反相求和电路,有效抑制了直流漂移,使电路具有极好的直流稳定性和增益稳定性,该电路主要适用于快探测器,如硅雪崩光电二极管探测器,也可用于加速器束流诊断系统,放大来自束流位置探针、相位探针的微弱信号。

80MeV/u ~(12)C~(6+)离子辐照小鼠头部对骨髓细胞周期分布的影响

研究重离子辐照小鼠头部对骨髓细胞周期分布的影响,为重离子放射治疗癌症和太空防护提供基础数据。80MeV/u能量的12C6+离子对BALB/c小鼠头部给以0、0.5、1、2、4、10Gy的照射,用流式细胞仪测骨髓细胞周期分布。随着重离子辐照剂量的增加,G1/G0期细胞出现明显阻滞(P<0.05),而G2/M期细胞出现显著减少(P<0.05)。说明重离子辐照小鼠头部对小鼠骨髓细胞周期分布有明显影响,也同时表明电离辐射对骨髓细胞周期分布的影响也有一种间接作用。

Are Chinese loess deposits essentially continuous?

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