7.8μm二级分布反馈量子级联激光器

报道了基于应变补偿的InP基In0.53+xGa0.47-xAs/In0.52-yAl0.48+yAs分布反馈量子级联激光器.采用二级光栅作为反馈,激射工作波长为7.8μm,在1%占空比,5kHz频率的工作条件下,在93～173K的温度范围内,单模发射光谱边模抑制比均超过20dB,调谐系数dλ/dT=0.5125nm/K.在93K时,峰值功率为30mW,直到153K时,峰值光功率仍达到12mW.

赝配GaAs/In_(0.2)Ga_(0.8)As量子阱导带不连续量的C-V和电容瞬态测量

半导体材料开放实验室基金,国家自然科学基金

Surface Emitting Distributed Feedback Quantum Cascade Laser around 8.3 mu m

We demonstrate surface emitting distributed feedback quantum cascade lasers emitting at wavelengths from 8.1 mu m at 90 K to 8.4 mu m at 210 K. The second-order metalized grating is carefully designed using a modified coupled-mode theory and fabricated by contact lithography. The devices show single mode behavior with a side mode suppression ratio above 18 dB at all working temperatures. At 90 K, the device emits an optical power of 101 mW from the surface and 199 mW from the edge. In addition, a double-lobe far-field pattern with a separation of 2.2 degrees is obtained in the direction along the waveguide.

Effects of oriented substrates on cell morphology, the cell cycle, and the cytoskeleton in Ros 17/2.8 cells

Absence of gravity or microgravity influences the cellular functions of bone forming osteoblasts. The underlying mechanism, however, of cellular sensing and responding to the gravity vector is poorly understood. This work quantified the impact of vector-directional gravity on the biological responses of Ros 17/2.8 cells grown on upward-, downward- or edge-on-oriented substrates. Cell morphology and nuclear translocation, cell proliferation and the cell cycle, and cytoskeletal reorganization were found to vary significantly in the three orientations. All of the responses were duration-dependent. These results provide a new insight into understanding how osteoblasts respond to static vector-directional gravity.

同位素~(208)Pb靶的制备

介绍了一种弧形靶框夹芯208Pb靶的制备工艺,包括核靶的制备装置和制备方法、核靶厚度和均匀性的控制和测量方法,并对结果进行了讨论。制备采用旋转蒸镀法,该法可以大大提高材料的利用率。所制靶的结构为30μg/cm2C+361μg/cm2208Pb+15μg/cm2C,同一次所制的靶平均厚度为361μg/cm2,不均匀性小于9.8%。其性能能够很好地满足超重核实验研究的要求。

一种新型的8路电荷灵敏前置放大器

本文介绍了一种新型专用的多路电荷灵敏前置放大器,其路数最多为八路,这种电荷灵敏前置放大器采用新的设计方案,该前放主要采用低噪声场效应晶体管和集成运算放大器构成,其等效输入噪声小于等于2.2keV。该前放具有电路结构简单、体积小、输出信号上升时间快、噪声低、稳定性好等特点。并对它的设计以及特点作了较详细的阐述。

An 8.1 Ma calcite record of Asian summer monsoon evolution on the Chinese central Loess Plateau

IEECAS SKLLQG

The influence and chronological uncertainties of the 8.2 ka cooling event on continental climate records in China

IEECAS SKLLQG

黄土高原8．1Ma以来方解石记录的夏季风演化

IEECAS SKLLQG

Pollen record from red clay sequence in the central Loess Plateau between 8.10 and 2.60 Ma

IEECAS SKLLQG

利用贺兰山北部树轮资料重建过去270年以来6-8月平均干燥指数

IEECAS SKLLQG