Geometric transformations of optical orbital angular momentum spatial modes

With the aid of the bosonic mode conversions in two different coordinate frames, we show that (1) the coordinate eigenstate is exactly the EPR entangled state representation, and (2) the Laguerre-Gaussian (LG) mode is exactly the wave function of the common eigenvector of the orbital angular momentum and the total photon number operator. Moreover, by using the conversion of the bosonic modes, theWigner representation of the LG mode can be obtained directly. It provides an alternative to the method of Simon and Agarwal.     

Broadband LWIR and MWIR absorber by trapezoid multilayered grating and SiO<Subscript>2</Subscript> hybrid structures

A broadband metamaterial absorber with high absorption simultaneously in mid-wave infrared (MWIR) and long-wave infrared (LWIR) was proposed. In the MWIR, the absorption higher than 0.8 is from 4 to 6.3 µm, while the absorption in the LWIR is from 8.7 and 9.6 µm. The absorber is insensitive to the incident angle. The broadband absorption in the MWIR is due to the slow-light effect of the trapezoid multilayered grating structure. And the broadband absorption in the LWIR is due to the phonon polariton resonant of trapezoid SiO₂ layer. In the broadband high absorption region, the atmosphere is transparent, which may greatly promote the practical application of the absorber in double-color IR imaging, detecting, infrared stealth and thermal emitting.     

Effect of Si addition on the stability of Al-10Ti-5Cu-xSi alloy/SiC interface

The effect of Si addition on the interfacial stability of Al-10Ti-5Cu-xSi (x = 0, 5, 10, 15) alloy/SiC is investigated. SiC and the Al-10Ti-5Cu-xSi alloys were compacted to obtain a stable interface with 10 wt% Si. Analysis of the processing conditions and the microstructures indicated that an excellent Ti₃SiC₂ phase had been formed and the deleterious Al₄C₃ phase had been eliminated successfully by the addition of 10 wt% Si to the Al-10Ti-5Cu alloy. Formation of Ti₃SiC₂ increased at first and then decreased, while the formation of Al₄C₃ was gradually inhibited with increasing Si content. Ti₃SiC₂ possesses good chemical stability, and flexibility. However, Al₄C₃ degrades within few days, in composites exposed to ambient conditions. The presence of Ti₃SiC₂ at the interface and the elimination of Al₄C₃ together ameliorate the bonding of Al-10Ti-5Cu-xSi alloy to SiC, thereby improving the interfacial stability of Al-10Ti-5Cu-xSi/SiC.     

ICP-AES结合SVDV技术应用于饮用水品质检测性能诊断

采用电感耦合等离子体原子发射光谱(ICP-AES)技术,通过轴向、径向、同步垂直双向(SVDV)三个视角配置,快速检测生活饮用水样本中的As,Ba,Mg和Ni等微量元素。ICP-AES光谱仪在三个检测视角均能实现快速预热,预热时间仅需2 min,而且,ICP-AES光谱的短期稳定性和长期稳定性表现良好,其相对标准偏差(RSD)均低于2%。以3份商业瓶装饮用水和2份添加标准物的饮用水为检测的对象,利用ICP-AES技术结合SVDV视角,分别从轴向和SVDV两个视角检测As,Ba,Cr,Cu,Mn,Mo,Ni,V和Zn等元素,利用水微量元素含量的国家标准来验证结果的准确性,这两个视角的检测具有较高的准确度和灵敏度。检测所得结果符合国家环境保护总局发布的饮用水微量元素限制标准,并符合国际卫生组织的标准,满足人类所需饮用水标准要求。     

具有光电倍增的宽光谱三相体异质结有机彩色探测器

实验研究了P3HT：PBDT-TT-F：PCBM三相体异质结活性层光谱拓宽及其材料混合度对探测器光电特性的影响以及陷阱辅助光电倍增的机理.在此基础上,获得了一个覆盖350–750 nm波长范围的彩色探测器.该探测器在-1 V低偏压下红绿蓝三基色的光响应度和外量子效率分别达到了470,381,450 mA/W和93%,89%,121%,比探测率均接近10¹² Jones,且各基色的特性参数最大平均相对偏差均小于20%,同时频率带宽分别达到了5,8,8 kHz.结果表明：在保持二相体异质结薄膜原有微观形貌下,掺入少量光谱拓宽材料可实现活性层吸收光谱的拓宽.利用能级陷阱中电子的辅助作用引入外电路空穴注入,可实现探测器光电倍增.通过调节三相材料的混合度可实现基色间探测能力的均衡性.     

基于USB的卫星通用化地面测试软件的设计

本文将软件工程中的组件技术引入卫星测试领域,提出了利用测试功能组件构建通用化测试软件的设计思路。首先,对现有卫星型号的地面测试任务做共性研究;其次,总结通用化测试软件的研制需求;然后,进行软件概要设计和详细设计;最后,软件实现。经验证,本文提出的基于USB接口的卫星通用化地面测试软件,通用性强,能较好的满足多个分系统单机设备的测试要求。     

同轴结构中压力波法测量空间电荷分布的物理模型研究

从压力波法测量平板样本中空间电荷分布的理论分析出发,提出了对于同轴结构的固体电介质中空间电荷分布的压力波法测量的物理模型,并得出了测量电流的解析的数学表达式.依据泊松方程,考虑样品内的电场强度、介电常数和空间电荷密度随外界声波扰动而发生变化,将圆柱试样受到的压力波的影响分解成样品形变和质点位移两部分,进而得到了以同轴结构中空间电荷分布的压力波法测量的电压与电流表达式.测量电流的数学表达式表明,对于同轴结构,压力波法的测量电流信号不像平板结构中那样基本正比于空间电荷分布,而是应该做进一步的修正处理.     

A piperidinium-based ester-functionalized ionic liquid as electrolytes in Li/LiFePO<Subscript>4</Subscript> batteries

A new functionalized ionic liquid (IL) based on cyclic quaternary ammonium cations with ester group and bis(trifluoromethanesulfonyl)imide ([TFSI]^?) anion, namely, N-methyl-N-methoxycarbonylpiperidinium bis(trifluoromethanesulfonyl)imide ([MMOCPip][TFSI]), was synthesized and characterized. Physical and electrochemical properties, including Li-ion transference number, ionic conductivity, and electrochemical stability, were investigated. The electrochemical window of [MMOCPip][TFSI] was 6 V, which was wide enough to be used as a common electrolyte material. The Li-ion transference number of this IL electrolyte containing 0.1 M LiTFSI was 0.56. The half-cell tests indicated that the [MMOCPip][TFSI] obviously improved the cyclability of a Li/LiFePO₄ cell. For the Li/LiFePO₄ half-cells, after 20 cycles at room temperature at 0.1 C, the discharge capacity was 109.7 mAh g^?1 with 98.7% capacity retention in the [MMOCPip][TFSI]/0.1 M LiTFSI electrolyte. The good electrochemical performance demonstrated that the [MMOCPip][TFSI] could be used as electrolyte for lithium-ion batteries.     

Aging effect in the BESIII drift chamber

As the main tracking detector of BESIII, the drift chamber provides accurate measurements of the position and the momentum of the charged particles produced in e+e-collisions at BEPCII. After six years of operation, the drift chamber is suffering from aging problems due to huge beam-related background. The gains of the cells in the first ten layers show an obvious decrease, reaching a maximum decrease of about 29% for the first layer cells. Two calculation methods for the gain change(Bhabha events and accumulated charges with 0.3% aging ratio for inner chamber cells) give almost the same results. For the Malter effect encountered by the inner drift chamber in January 2012, about 0.2% water vapor was added to the MDC gas mixture to solve this cathode aging problem.These results provide an important reference for MDC operating high voltage settings and the upgrade of the inner drift chamber.