High resistance AlGaAs/GaAs quantum cascade detectors grown by solid source molecular beam epitaxy operating above liquid nitrogen temperature

This work was supported by the National Research Projects of China (grant numbers are 60525406, 60736031, 60806018, 60906026, 2006CB604903, 2007AA03Z446 and 2009AA03Z403, 10990100, respectively). The authors would like to thank P Liang, Y Hu, H Sun, X L Zhang, B J Sun, H L Zhen and N Li for their help in processing and characterization.

WEPP模型坡面版在黄土丘陵沟壑区的适用性评价——以坡度因子为例

利用安塞试验站1985-1992年的气象观测数据和野外坡度径流小区径流和土壤侵蚀量监测资料,评价了WEPP模型在黄土丘陵沟壑区不同坡度条件下的适用性。结果表明,径流量的模拟值在10°、15°、20°、25°和28°五个坡度条件下,变化幅度不如实测值明显,但模拟值随坡度变化的趋势和实测值相一致;WEPP模型对次降雨、年平均和多年平均土壤侵蚀量模拟结果较好,且无论是模拟值在不同坡度之间的差值、还是模拟值随坡度变化趋势均与实测值接近。I30对WEPP模型模拟次降雨径流量有重要影响,当I30大于0.92mm/min,模型模拟误差较大。WEPP模型对次降雨土壤侵蚀量的模拟与PI30密切相关,当PI30大于129mm2/min时,模型模拟误差较大。∑PI30对WEPP模型模拟年平均径流量和侵蚀量有重要影响,当∑PI30大于150mm2/min时,模拟精度明显下降,且∑PI30对径流模拟影响较对土壤侵蚀模拟影响明显。WEPP模型对次降雨、年平均和多年平均径流量模拟的Nash-Sutcliffe有效性ME分别为0.914、0.912和0.617;对次降雨、年平均和多年平均土壤侵蚀量模拟的Nash-Sutcliffe有效性ME...

Effect of Annealing on Structural and Magnetic Properties of a Thick (Ga,Mn)As Layer

We investigate effects of annealing on magnetic properties of a thick (Ga,Mn)As layer, and find a dramatic increase of the Curie temperature from 65 to 115 K by postgrowth annealing for a 500-nm (Ga,Mn)As layer. Auger electron spectroscopy measurements suggest that the increase of the Curie temperature is mainly due to diffusion of Mn interstitial to the free surface. The double-crystal x-ray diffraction patterns show that the lattice constant of (Ga,Mn)As decreases with increasing annealing temperature. As a result, the annealing induced reduction of the lattice constant is mainly attributed to removal of Mn interstitial.

3μm GaInNAs/GasAs Quantum Well Resonant Cavity Enhanced Photodetector

A 1.3μm GaInNAs resonant cavity enhanced (RCE) photodetector (PD) has been grown by molecular beam epitaxy (MBE) monolithically on (100) GaAs substrate using a home-made ion-removed dc-plasma cell as nitrogen source. A transfer matrix method was used to optimize the device structure. The absorption region is composed of three GaInNAs quantum wells separated by GaAs layers. Devices were isolated by etching 130μm-diameter mesas and filling polyamide into grooves. The maximal quantum efficiency of the device is about 12% at 1.293μm. Full width at half maximum (FWHM) is 5.8nm and 3dB bandwidth is 304MHz. Dark current is 2 * 10~(-11) A at zero bias voltage. Further improvement of the performance of the RCE PD can be obtained by optimizing of the structure design and MBE growth conditions.

热退火对分子束外延生长的高纯GaAs薄膜中深能级的影响

于2010-11-23批量导入

基于.NET的四层结构及其在综合信息系统中的应用

阐述应用程序开发的三层结构的基本组织形式及存在的问题,提出了基于四层结构的应用程序开发模型及其带来的好处.结合七里村采油厂综合信息系统开发实例,对基于.NET的四层结构的应用程序开发技术进行了研究,实现了基于.NET的四层结构的部署,阐述了基于四层结构的具体实现策略,并在此基础上给出了基于四层结构的应用程序设计与开发的关键技术.

微结构疏水表面对界面流动的影响

<正>通过MicroPIV/PTV系统测量带有微结构的PDMS微流道(22μm×6μm,长8mm)内的速度分布。流道侧壁的PDMS微结构是通过软光刻微加工工艺制成,其特征宽度在1～10μm范围。为了研究微结构尺寸的影响,我们测量了3种不同尺度微结构对速度分布的影响。示踪粒子为200nm聚苯乙烯荧光粒子。实验管道Re约0.01。

西安附近丰水年秋季苹果林地土壤水分恢复研究

IEECAS SKLLQG

昆仑山北坡鸭子泉河阶地发育及其构造-气候意义

IEECAS SKLLQG