Influence of Oxygen Vacancy on Transport Property in Perovskite Oxide Heterostructures

Effect of oxygen vacancy on transport property of perovskite microstructures is studied theoretically. Compared with calculated and measured I-V curves, it is revealed that electron conduction plays an important role in the oxygen nonstoichiometry perovskite heterostructures even with hole-doped or un-doped material due to the oxygen vacancies. In addition, a detailed understanding of the influence of oxygen vacancy concentration and temperature on the conduction characteristics of oxide heterojunction with both forward and reverse biases is obtained by calculation.     

Enhanced Photoluminescence of InGaN/GaN Green Light-Emitting Diodes Grown on Patterned Sapphire Substrate

Green InGaN/GaN based light-emitting diodes （LEDs） are fabricated both on planar and wet-etched patterned sapphire substrates by metalorganic vapour phase epitaxy （MOVPE）. Their photoluminescence （PL） properties of the two samples are studied. The results indicate that the PL integral intensity of the green LED on the patterned substrate is nearly two times of that on the planar one within the whole measured temperature range. The enhanced PL intensity in the green LED on the patterned substrate is shown completely contributed from the extraction efficiency, but not from the internal quantum efficiency. The conclusion is supported by temperature-dependent PL analysis on the two samples, and the mechanisms axe discussed.     

Experimental Evidence of Two-Proton Emissions from 18Ne Excited State

Experiment ^18Ne＋^197 Au was performed in Heavy Ion Research Facility Radioactive Ion Beam Line at Lanzhou （RIBLL）. The nuclear energy levels of ^18Ne were built by complete kinematical reconstruction of the decay products and diproton decay were observed from ^18Ne excited states. At 6.15 MeV, the experimental relative momentum and angular correlations of the emitted protons are given. The obvious enhancement at ｜qrol｜= 23 MeV/c and θc.m. = 40° shows the experimental criterion of ^2He cluster decay from ^18Ne^q.     

双面加热环形通道内干涸点的确定

根据环形管通道内流体流动和换热的特点,以Kirillov和Smogalev提出的干涸点理论模型假设为基础,从最基本的质量守恒方程出发,并引入临界液膜厚度等相应的辅助模型,得到了双面加热环形通道内流动沸腾干涸点的理论模型。同时针对间隙为1.0mm和1.5mm的环形窄缝进行了低压低质量流速工况下干涸点的实验研究。比较发现理论模型预测值与实验结果基本相符。说明本文提出的理论模型适用于低压低流量条件下的窄环形通道。实验同时发现:环状流临界热流密度在系统压力为2.2MPa达到最大值,临界含汽量随质量流速的增大呈缓慢下降趋势。     

含氢添加剂对合成cBN的影响及腔体温度分布

 通过对Li基触媒下立方氮化硼的高温高压合成实验结果的分析,研究了在Li基触媒作为主要触媒及氢化物作为添加剂的环境下,立方氮化硼的生长情况。同时由合成后样品中立方氮化硼的生成区域对V型生长区温度梯度分布进行了分析讨论。     

宽脉冲网络信号源及应用

 通过对电探针工作原理的分析,提出采用宽脉冲网络源代替传统窄脉冲网络源的技术措施,以解决时常遇到的“提前导通”问题。模拟计算和实验测量结果表明：尽管受到提前导通的影响,采用宽脉冲网络源的电探针信号仍然能够分辨出冲击波或飞片、自由面到达观测点的时间信息,从而给出真实可信的时间测量值。     

Preliminary shielding analysis in support of the CSNS target station shutter neutron beam stop design

The construction of China Spallation Neutron Source (CSNS) has been initiated in Dongguan, Guangdong, China. Thus a detailed radiation transport analysis of the shutter neutron beam stop is of vital importance. The analyses are performed using the coupled Monte Carlo and multi-dimensional discrete ordinates method. The target of calculations is to optimize the neutron beamline shielding design to guarantee personal safety and minimize cost. Successful elimination of the primary ray effects via the two-dimensional uncollided flux and the first collision source methodology is also illustrated. Two-dimensional dose distribution is calculated. The dose at the end of the neutron beam line is less than 2.5 μSv/h. The models have ensured that the doses received by the hall staff members are below the standard limit required.     

连续变量量子纠缠增强实验的改进

通过在泵浦光和注入光路中加入高精细度模清洁器及提高实验系统锁定的精度,我们对连续变量量子增强的实验系统加以了改进,初始的EPR纠缠光场的正交振幅及正交位相分量的关联度分别从(2.4±0.2)dB,(2.4±0.2)dB提高至(4.0±0.2)dB,(3.9±0.2)dB,而输出纠缠态光场的关联度分别由原来的(3.0±0.2)dB,(3.0±0.2)dB提高至(5.6±0.2dB),(5.5±0.2)dB。与此前的实验系统相比,纠缠增强的效率及结果均有一定提高。     

基于Dual-Mode MMA+MDD双模式T/2分数间隔盲均衡算法的研究

均衡技术是用来解决通信系统中码间干扰的常用方法.针对传统恒模算法的收敛速度和稳态剩余码间干扰大的缺点,将双模式多模算法和改进型判决引导算法结合起来,并且应用于分数间隔盲均衡器中.该算法初期用双模式算法收敛均衡器,然后切换到改进型判决引导算法中进一步收敛,由于分数间隔均衡器解决了波特间隔均衡器因抽样率不高带来的频谱混叠问...