Rotation-invariant pattern recognition using morphological phase-only correlation

We present a rotation-invariant nonlinear correlator based on the circular harmonic filter (CHF) and the previously proposed morphological phase-only correlator (MPC) [Q. Wang, S. Liu, Opt. Commun. 244 (2005) 93]. We refer to this correlator as a rotation-invariant MPC (RIMPC). Through computer simulation, we compare the output results of RIMPC with those of rotation-invariant MC (RIMC) and CHF when input scene is corrupted by salt-and-pepper noise, white additive Gaussian noise and cluttered background. Our results show that RIMPC yields higher discriminability, sharper and higher correlation peaks and displays better stability against the above three kinds of noise than do the RIMC and common CHF.     

基于Android网络恶意行为检测系统的应用研究

目前Android系统是当今网络用户最对的应用系统之一,而随着科学技术的发展,对于Android系统的恶意行为软件也逐渐增多,给当前的应用用户的财产以及私人信息安全带来了很大的威胁,严重的迟缓了当前移动通信网络技术以及相关于应用客户端的推广。为此本文根据Android系统的特有机构设计出一种基于Binder信息流的自动检测恶意行为系统,以此来解决对于当前网络安全对于Android系统用户带来的负面影响。根据目前网络中的应用通信信息,检测可能存在的泄露用户信息的应用软件为目标,建立信息矢量图以此来分析当前网络中的恶意行为。通过对软件进行检测,研究可实用性和检测效果,结果显示其识别率可以达到100%,并且软件运行只占有内存的7%,结果可以达到当前的Android用户的使用范围。     

悬浮液进样-原子吸收法测定中药材中铜、锌、铁

本文提出了一种悬浮液进样－火焰原子吸收法测定中药材－－怀药（怀山药、怀牛膝、怀菊花）的新方法。并成功地进行了Cu,Zn,Fe的测定。将粉碎后的怀药悬浮于琼脂胶体中制成悬浮液，对悬浮剂的选择及化不干扰的消除进行了考察。将试液喷入空气－乙炔火焰中，用标准加入法测定，结果与HNO3＋H2SO4＋HClO4处理法一致。t检验结果表明：两种样品处理方法之间无显著性差异，可以采用悬浮液进样法取代HNO3＋H2SO4＋HClO4处理法，该方法快速简便、安全，有效，结果令人满意。     

载流子迁移率对单层有机发光二极管复合效率的影响

建立了在单层有机发光二极管中电场强度不太大(E≤104Vcm)的情况下,载流子注入、传输和复合的理论模型.通过求解非线性Painleve方程得出了电场强度随坐标变化的解析函数关系式以及电流密度随电压变化关系,给出了电流密度以及器件的复合效率在不同的载流子迁移率情况下随电压变化关系图像.结果表明,复合效率受载流子迁移率影响较大,在器件中多数载流子应具有较低的迁移率,而少数载流子应具有较高的迁移率,这样有利于载流子的注入和传输,从而可提高发光效率.并且得出当空穴迁移率大于电子迁移率时,复合区域偏向阴极,反之亦 关键词： 单层有机发光二极管 复合效率 迁移率     

高功率905 nm InGaAs隧道结串联叠层半导体激光器

设计出了隧道结串联叠层半导体激光器结构,采用分子束外延进行激光器材料的外延生长,材料经过光刻、腐蚀、欧姆接触、解理、腔面镀高反射/减反射膜、焊装等工艺,制作成条宽200 m、腔长800 m 的半导体激光器。两隧道结激光器在脉冲宽度100 ns,重复频率10 kHz,30 A工作电流下输出功率达到80 W,峰值发射波长为905.6 nm,器件的阈值电流为0.8 A,水平和垂直方向的发散角分别为7.8和25。     

光锥与CCD耦合器件调制传递函数的测试方法

采用直接对倾斜刀口成像的方法测量光锥与CCD耦合器件的调制传递函数.这种方法对静止刀口成像,利用刀口与光锥纤维列间的一定倾斜角度,在垂直于刀口的不同行之间形成不同的值,代替了传统刀口扫描中的扫描装置,并无需保证刀口与阵列的平行,相应地减小了测量误差. 在数据处理中采用了二次平均法,即对同一幅图像得出的不同位置值进行平均及多次测量结果平均,在一定程度上消除了由于离散性产生的空间非平移不变性的影响.     

双带频率选择表面设计

为了实现频率选择表面(FSS)的双带特性,设计了由矩形栅格和三圆环组合单元FSS。对FSS的谱域求解方法进行了详细的描述。采用谱域法分析了不同角度和极化入射波下FSS的频率响应性能。结果表明,所设计的FSS对于不同入射角度和极化电磁波具有稳定的双带、平顶传输及陡峭下降边缘特性。双带特性大致表现为1.8～5.4GHz的阻带和5.4～20.0GHz的通带。阻带谐振频率稳定在3.1GHz左右,而通带在-4dB的平顶传输带宽达14.3GHz以上。其陡峭下降边缘特性表现为S波段信号强烈反射,而其他波段信号通过,从而实现多波段通讯。该结构FSS可应用于卫星通信、雷达罩及其他相关领域。     

Design of all-optical temporal differentiator using a Moir fiber grating

We design and demonstrate an all-optical temporal differentiator based on a simple Moir fiber grating operated in reflection. The simulation results prove that a single Moir fiber grating with only one π-phase shifted point can act as the first-order temporal differentiator and that a Moir fiber grating incorporating two symmetrical π-phase shifted points can act as the second-order temporal differentiator. A practical Moir fiber grating is fabricated, thereby proving that such a grating can act as the first-order temporal differentiator. Our results verify the feasibility, flexibility, and accuracy of the proposed method.     

Electric-field control of nonvolatile magnetization in Co40Fe40B20/Pb(Mg(1/3)Nb(2/3))(0.7)Ti(0.3)O3 structure at room temperature

We report a large and nonvolatile bipolar-electric-field-controlled magnetization at room temperature in a Co(40)Fe(40)B(20)/Pb(Mg(1/3)Nb(2/3))(0.7)Ti(0.3)O(3) structure, which exhibits an electric-field-controlled looplike magnetization. Investigations on the ferroelectric domains and crystal structures with in situ electric fields reveal that the effect is related to the combined action of 109° ferroelastic domain switching and the absence of magnetocrystalline anisotropy in Co(40)Fe(40)B(20). This work provides a route to realize large and nonvolatile magnetoelectric coupling at room temperature and is significant for applications.     

Effect of the luminol signal enhancer on the chemiluminescence intensity and kinetics

The novel p-phenol derivatives, 4-(1-imidazolyl)-phenol, 4-hydroxybiphenyl, 4-hydroxy-4′-iodobiphenyl were employed as highly potent signal enhancers of luminol-hydrogen peroxide (H₂O₂)-horseradish peroxidase (HRP) chemiluminescence (CL) system. The CL reaction conditions were optimized, and the enhancement characteristics of these enhancers were compared with each other. The employment of these molecules greatly affected important assay parameters. Practically, the use of a novel enhancer, even a slightly change of the structure (or concentration) of 4-substituted phenol derivative, could affect assay properties quite dramatically. Furthermore, the use of different enhancers in the luminol–H₂O₂–HRP system can affect not only the intensity of the CL signal, which is well known, but also its kinetics. The experiment data indicated that the stronger intensity was combined with a more rapid decrease of the CL signal.