High-precision determination of lattice constants and structural characterization of InN thin films

X-ray diffraction and Rutherford backscattering/channeling were used to characterize the crystalline quality of an InN layer grown on Al2O3(0001) Using metal-organic chemical-vapor deposition. A full width at half maximum of 0.27 degrees from an InN(0002) omega scan and a minimum yield of 23% from channeling measurements show that this 480-nm-thick InN layer grown at low temperature (450 degrees C) has a relatively good crystalline quality. High-resolution x-ray diffraction indicates that the InN layer contains a small fraction of cubic InN, besides the predominant hexagonal phase. From this InN sample, the lattice constants a=0.353 76 nm and c=0.570 64 nm for the hexagonal InN and a=0.4986 nm for the cubic InN were determined independently. 2 theta/omega-chi mapping and a pole figure measurement revealed that the crystallographic relationship among the cubic InN, the hexagonal InN, and the substrate is: InN[111]parallel to InN[0001]parallel to Al2O3[0001] and InN{110}parallel to InN{1120}parallel to Al2O3{1010}, and that the cubic InN is twinned. Photoluminescence measurements indicate that the band-gap energy of this sample is approximately 0.82 eV. (c) 2006 American Vacuum Society.

基于STM-64的甚短距离并行光传输系统

研究了STM-64数据帧的转换映射技术,利用垂直腔面发射激光器(VCSEL)列阵光源和PIN列阵探测器成功研制出10 Gb/s的甚短距离12信道SDH并行光传输系统,该系统结构紧凑,具有检错和纠错功能。跟传统的10 Gb/s串行光传输系统相比,本系统降低了对单路器件传输性能的要求。经SDH传输测试仪测试,系统能实现无误传输。

64通道100ps时间-数字变换模块的研制

兰州重离子加速器冷却储存环外靶实验终端的多丝漂移室通过测量带电粒子的漂移时间得到径迹信息。本文介绍的64通道高精度时间-数字变换模块,采用高密度的连接器和多通道的时间-数字变换芯片HPTDC,模块的数据通过PXI总线传输到计算机,时间精度可达100ps。

平板型光电倍增管64路信号的简化处理

HAMAMATSU的H8500型64路多阳极平板型光电倍增管以其非常优越的位置分辨被广泛地应用于各种小型探测装置和大型阵列探测装置,多信号的有效、快速和最为经济的简化电子学线路读出成为多阳极光电倍增管非常重要的研究内容。基于DPC电桥简化处理多阳极光电倍增管信号,在未采用铅准直的情况下测量137Csγ源最好位置分辨(FWHM)达到了2mm左右。

Projectile fragmentation of Kr-86 at 64 MeV/nucleon

We measured fragmentation cross sections produced using the primary beam of Kr-86 at 64 MeV/nucleon on Be-9 and Ta-181 targets. The cross sections were obtained by integrating the momentum distributions of isotopes with 25 <= Z <= 36 measured using the RIPS fragment separator at RIKEN. The cross-section ratios obtained with the Ta-181 and Be-9 targets depend on the fragment masses, contrary to the simple geometrical models. We compared the extracted cross sections to EPAX; an empirical parametrization of fragmentation cross sections. Predictions from current EPAX parametrization severely overestimate the production cross sections of very neutron-rich isotopes. Attempts to obtain another set of EPAX parameters specific to the reaction studied here to extrapolate the neutron-rich nuclei more accurately have not been very successful, suggesting that accurate predictions of production cross sections of nuclei far from the valley of stability require information of nuclear properties that are not present in EPAX.

64通道一维位置灵敏电流分布探测器及其数据获取系统；A 64-Channel Position Sensitive Current Distribution Detector with Data Acquisition System

针对高流强粒子束与绝缘毛细管相互作用的特点,设计制作了一套64通道一维位置灵敏电流分布探测器及其配套的数据获取系统,该探测器可分辨最小直径为1mm的束斑,通过数据获取系统可实现可视化自动数据采集。用2nA和200—2000eV电子对探测器进行了定标,并用10μA和2000eV的电子束穿越锥形毛细管后的出射电子,对探测器及数据获取系统进行测试,获得了出射粒子的位置分布谱及能量信息。

（一）兰州重离子加速器束流能量、能散测量（二）中能~(12)C + ~(64)Ni, ~(58)Ni碎裂反应的实验研究

本论文通过讨论选择了简单易行的弹性散射法来测量兰州重离子加速器流能量、能散，描述了整个实验的准备、进行及数据处理，并讨论、修正了所得的实验结果，得到了~(12)C束流能散为(2.74 ± 0.14) * 10~(-2)，能量经刻度为每核子46.4MeV/u。本工作还拟采用飞行时间法来测量束流能量的绝对值，以检验弹性散射法测得的能量值，而且已设计制作了用作起始探测器的微道板（MCP）零时探测器，上器进行了必要的高调试，用MCP零时探测器作为起始探测器，Si半导体探测器作为终止探测器，对于10MeV/uα粒子，得到了好于560ps的总时间分辩，完全可用于中能重离子实验探测

UNUSUAL VOLTAMMETRIC BEHAVIOR OF AN ELECTROCHEMICALLY SYNTHESIZED CONDUCTING PLATINUM CLUSTER COMPOUND K-1.64[PT(C2O4)(2)]

The compound K-1.64[Pt(C2O4)(2)] was electrochemically synthesized on a glassy carbon electrode using both single-potential step and cyclic voltammetry techniques; voltammetric behaviour of the working electrode was changed dramatically with deposition of

'We are not Seeking Strength for its Own Sake': The British Labour Party, West Germany and the Cold War, 1951-64

Hughes, R. (2002). 'We are not Seeking Strength for its Own Sake': The British Labour Party, West Germany and the Cold War, 1951-64. Cold War History. 3(1) pp.67-94 RAE2008

The contribution of warlordism to the disintegration of the western Roman army (c. AD 395-480)

My thesis investigates the dynamics behind the changing nature of the leadership of the western Roman army in the fifth century through the concept of ‘warlordism’. I carried this out by analyzing those cases of insubordination and military unrest in the officer class of the western Roman army, which can be shown to be linked to the slow decline of central authority and the imperial office in the period 395-480. My thesis demonstrates that theories of ‘Warlordism’, as developed in social sciences, can be useful for both the late Imperial west as for other eras of ancient history, such as the late Roman republic. Warlordism was a way of continuing politics, if necessary by military means, when commanders found themselves outside the legitimate framework. Unlike the case of usurpation of the imperial office, when there was little hope of achieving permanent recognition and acceptance, it offered insubordinate officers a chance of returning to the ruling imperial regime depending on circumstances and the success of their resistance. I propose that warlordism functioned as an alternative to usurpation, a tool for military dissidence, fuelled by an economy of violence. Contrary to modern warlordism, the warlordism of the fifth century AD represented a transient phase which no imperial commander was willing to prolong indefinitely. At some stage, given the means, warlords in the western Roman army wanted to become part of the imperial echelon again. Yet these alternative methods of violent opposition, and the acquisition of force through private means, ensured the breakdown of the state’s monopoly on violence and the disintegration of centralized armies. What started as an accidental revolution became a new form of military rule.

SN2003du: 480 days in the life of a normal type Ia supernova

Aims. We present a study of the optical and near-infrared (NIR) properties of the Type Ia Supernova (SNIa) 2003du.

64-point Fourier transform chip for digital television applications

A 64-point Fourier transform chip is described that performs a forward or inverse, 64-point Fourier transform on complex two's complement data supplied at a rate of 13.5MHz and can operate at clock rates of up to 40MHz, under worst-case conditions. It uses a 0.6µm double-level metal CMOS technology, contains 535k transistors and uses an internal 3.3V power supply. It has an area of 7.8×8mm, dissipates 0.9W, has 48 pins and is housed in a 84 pin PLCC plastic package. The chip is based on a FFT architecture developed from first principles through a detailed investigation of the structure of the relevant DFT matrix and through mapping repetitive blocks within this matrix onto a regular silicon structure.