Improving Cu2ZnSnS4 (CZTS) solar cell performance by an ultrathin ZnO intermediate layer between CZTS absorber and Mo back contact

The effects of an ultrathin ZnO intermediate layer deposited at the CZTS/Mo interface on CZTS solar cell performance have been investigated in this work. The ZnO layer inhibits the generation of MoS₂ layer and the formation of voids in the CZTS absorber. Consequently, the incorporation of this layer reduces the series resistance and increases the shunt resistance, which boosts photovoltaic conversion efficiency from 1.13% to 4.3%. (© 2014 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim)     

Material growth and device fabrication of terahertz quantum-cascade laser based on bound-to-continuum structure

The terahertz quantum-cascade laser （THz QCL） based on bound-to-continuum structure is demonstrated. The X-ray diffraction measurement of the material shows a high crystalline quality of the active region. A THz QCL device was fabricated with semi-insulating surface-plasmon waveguide. The test device is lasing at about 3 THz and operating up to 60 K. It shows a single frequency property under different drive currents and temperatures. At 9 K, the maximum output power is greater than 2 mW with a threshold current density of 159 A/cm2.     

利用异或运算和编码约束的降维LDP人脸识别方法

为了有效表示面部特征,在局部方向模式(LDP)的基础上,提出降维局部方向模式(RDLDP)。首先,修改LDP编码模式约束以完成模式的重构,通过对LDP码进行异或运算来计算每个块的单一码;然后,将所得编码图像划分为生成直方图,连接所有区域的直方图块以形成最终描述符。最后,计算特征向量间的卡方相异性度量值,并使用最近邻分类器完成最终的人脸识别。实验采用了三个公开的标准数据库FERET、扩展YALE-B和ORL。实验结果验证了提出算法的有效性。与其他基于局部描述符的先进方法相比,提出方法在准确度和错误识别率等方面更优。     

Measurement and analysis of fission rates in a spherical mockup of uranium and polyethylene

Measurements of the reaction rate distribution were carried out using two kinds of Plate Micro Fission Chamber （PMFC）. The first is a depleted uranium chamber and the second an enriched uranium chamber. The material in the depleted uranium chamber is strictly the same as the material in the uranium assembly. With the equation solution to conduct the isotope contribution correction, the fission rate of 238U and 235U were obtained from the fission rate of depleted uranium and enriched uranium. Then, the fission count of 238U and 235U in an individual uranium shell was obtained. In this work, MCNP5 and continuous energy cross sections ENDF/BV.0 were used for the analysis of fission rate distribution and fission count. The calculated results were compared with the experimental ones. The calculation of fission rate of DU and EU were found to agree with the measured ones within 10% except at the positions in polyethylene region and the two positions near the outer surface. Because the fission chamber was not considered in the calculation of the fission counts of 238U and 235U, the calculated results did not agree well with the experimental ones.     

强碱胁迫枯草芽孢杆菌芽孢致死的拉曼光谱研究

应用单细胞拉曼分析技术结合PCA方法,以枯草芽孢杆菌芽孢为对象,以强碱为诱导剂实时记录芽孢生理变化过程,探究芽孢在强碱胁迫下的致死机制。实验表明,枯草芽孢杆菌芽孢和其萌发后芽孢在一定范围均有一定的耐受强碱能力,但萌发后芽孢的耐受力明显下降,主要原因是释放了维持其抗性及稳定性的特有Ca2+-DPA的保护;芽胞受强碱胁迫也会有少量Ca2+-DPA释放过程的行为特征,但通过分析所记录的光谱数据结果表明,其释放行为不同于由L-丙氨酸引起的芽孢的正常Ca2+-DPA释放过程。通过PCA比较分析强碱胁迫芽孢和萌发后芽孢Ca2+-DPA释放过程,主要是强碱破坏芽孢膜结构,膜损伤后强碱比较容易进到芽孢内部从而破坏蛋白质的主链结构链及核酸;芽孢膜通道也可能受到强碱的伤害,造成微量Ca2+-DPA的释放。     

粒子-转子模型和推转壳模型中的能谱统计分析

用粒子–转子模型和推转壳模型研究了6个粒子分别填充在单j壳和双j壳上的混沌行为.分析了单j壳和双j壳情况下能谱的最近邻能级间距分布和谱刚度随自旋及推转频率的变化,结果表明,当组态空间大小不变时,系统在双j壳(g_7/2+d_5/2)情况下比在单j壳(i_13/2)情况下更规则,而当组态空间从单j壳(i_13/2)扩大到双j壳(i_13/2+g_9/2)时,系统的混沌程度变化不大.同时比较了将6个粒子的两体相互作用分别取为δ力和对力时的系统的混沌行为     

PSⅡ中蛋白二级结构中β聚合效应的红外光谱研究

利用Fourier变换红外光谱（FTIR）方法研究了光系统Ⅱ（PSⅡ）膜颗粒中蛋白二级结构在高温条件下的β聚合效应。具有生物活性和高温蛋白的β聚合样品的红外光谱测量温度均是室温，它们的酰胺Ⅰ吸收带被用来对两种样品的特性进行定量的分析。光谱的分析方法采用了直接Lorentz线型拟合，光谱结果表明光系统Ⅱ二级结构在400℃下发生热变性后，其红外光谱将发生很强的不可逆的变化。但其红外光谱与活性PSⅡ蛋白一样仍可用3个Lorentz线型拟合，显示了FTIR红外光谱方法在研究蛋白热变性方面的优越性。     

Thermal shock induced nanocrack as high efficiency surface conduction electron emitter

Significant emission current enhancement has been achieved for surface conduction electron emitter, due to the special three-dimensional nanocrack structure fabricated by the thermal shock process. The three-dimensional configuration strongly changed the electric field distribution and controlled the emission electron trajectory. Thermal shock treatment was also used to increase the edge roughness of the nanocrack and thereby dramatically improved the field emission characteristics. Stable and uniform electron emission was observed with turn-on voltage of 150 V. The surface conduction current of 400 μA for 6 cells was obtained with the detector voltage of 1 kV and the gap voltage of 170 V.     

石英光纤受γ射线辐照实验

阐述了有机包层和石英包层的石英光纤受辐照的结果,从实验中我们发现低剂量的辐照使光纤的透过率有所上升,简单地分析了其机理,同时阐述了其他中高剂量的光纤辐照结果,得到了一些有益的结论。