基于ASP的WEB数据库访问技术

随着Internet网络的飞速发展,人们对于网络的需求日以渐进.各种WEB数据库访问技术都在日益完善和提高,ASP就是一种日渐成熟的访问技术.本文就ASP在Web数据库开发方面的应用做了深入的研究,介绍了ASP的基本概念、工作原理,讨论了ASP和ADO访问Web数据库的方法,列举了几种常见的访问技术,主要对ASP技术进行了分析.     

一种高速雪崩光电探测器

High-speed avalanche photodiodes are widely used in optical communication systems. Nowadays, separate absorption charge and multiplication structure is widely adopted. In this article, a structure with higher speed than separate absorption charge and multiplication structure is reported. Besides the traditional absorption layer, charge layer and multiplication layer, this structure introduces an additional charge layer and transit layer and thus can be referred to as separate absorption, charge, multiplication, charge and transit structure. The introduction of the new charge layer and transit layer brings additional freedom in device structure design. The benefit of this structure is that the carrier transit time and device capacitance can be reduced independently, thus the 3 dB bandwidth could be improved by more than 50% in contrast to the separate absorption charge and multiplication structure with the same size.     

基于光强传输方程与SLM的快速相位恢复

基于光强传输方程（TIE）的相位恢复技术,可以通过测量一系列垂直于光轴分布的散焦强度图,直接求解得到光场的相位信息。传统的基于TIE的强度图像采集系统在获得散焦图像时需要机械移动。通过在空间光调制器（SLM）上加载透镜相位图,使其实现可编程透镜的功能,任意改变此透镜的焦距值,可以实现不同的散焦距离,从而避免采集图像过程中CCD的移动。根据不同的算法理论,设计了两种光强图像采集系统。由于日常生活中使用相机拍照时,透镜的相位调制作用不可忽略,使用SLM代替含透镜的光传播模型中透镜的作用,设计了第一种实验装置。此外,通过在4f系统的频率域位置放置SLM,设计了第二种实验装置。真实实验的结果验证了这两种方法的有效性和正确性。     

海娇颜片中原花青素含量快速测定方法优化

目的优化快速测定海娇颜片中原花青素含量的分析方法。方法通过加标回收率法发现采用铁盐催化比色法测定海娇颜片中原花青素时的干扰成分,并分别采用大孔树脂柱及乙醇沉淀-离心2种方法对样品进行前净化处理。结果发现海娇颜片中鱼胶原蛋白肽对原花青素的测定存在较大干扰,优化前测得原花青素含量为1.22%,经大孔树脂柱净化后测得其含量为2.15%,而经乙醇沉淀-离心净化后测定其含量为3.11%,接近理论值。结论乙醇沉淀-离心法能显著去除干扰成分,提高原花青素含量测定的准确度,是较优的样品预处理方法。该研究可为相关产品中原花青素含量快速测定方案的制定提供参考依据。     

High-responsivity 40 Gbit/s InGaAs/InP PIN photodetectors integrated on siliconon-insulator waveguide circuitss

This paper presents a high-responsivity and high-speed InGaAs/InP PIN photodetector integrated onto the silicon waveguide substrate utilizing the divinyltetramethyldisiloxane-benzocyclobutene (DVS-BCB) adhesive bonding method. A grating coupler is adopted to couple light from the fiber to the silicon waveguide. Light in the silicon photonic waveguide is evanescently coupled into the photodetector. The integrated photodetector structure is first simulated using the FDTD (finite difference time domain) solutions software and the simulation results show a detection efficiency of 95%. According to the simulation result, the integrated photodetector is fabricated. The measured responsivity of the fabricated integrated photodetector with a detection length of 30 μm is 0.89 A/W excluding the coupling loss between the fiber and the grating coupler and the silicon propagation loss at the wavelength of 1550 nm with a reverse bias voltage of 3 V. Measured 3-dB bandwidth is 27 GHz using the Lightwave Component Analyzer (LCA). The eye diagram signal test results indicate that the photodetector can operate at a high speed of 40 Gbit/s. The integrated photodetector is of great significance in the silicon-based optoelectronic integrated chip which can be applied to the optical communication and the super node data transmission chip of the high-performance computer.     

临床类毕业生焦虑抑郁及相关心理易感因素的调查

采用医院焦虑抑郁量表(HAD)、艾森克人格问卷(EPQ)、简易应对方式量表和领悟社会支持童表(PSSS)对181医学毕业生和127名参照对象进行问卷调查,以探索医学院校临床类毕业生焦虑、抑郁状况及相关心理易感因素关系.结果发现,医学院校临床类毕业生的焦虑、抑郁检出率分别为21.5%和17.1%,焦虑、抑郁情绪与人格特质、应对方式、领悟社会支持具有显著相关性.应对医学毕业生采取有针对性的心理健康教育措施,以防止或降低焦虑、抑郁情绪的发生,从而提高毕业生心理素质.     

SOI波导与InGaAs/InP光电探测器的集成

成熟的CMOS技术可制备无源光学器件,但高效光源和高性能光探测仍需要III~V族半导体材料。综述了近期III~V族外延片与SOI(silicon-on-insulator)波导集成的键合技术,按键合材料的不同分为无机和有机材料键合。着重分析了各种InGaAs/InP光电探测器与SOI波导集成的光耦合方案,并对其优缺点进行对比。同时给出设计的一种倏逝波耦合的InGaAs/InP光电探测器,用时域有限差分(FDTD)法对器件光学特性进行了模拟,以SOI上有机键合的方式,获得95%的探测器吸收效率,表明该SOI波导集成的光电探测器可实现小体积、低损耗及高响应度的光探测,符合片上光互连系统的要求。     

一种自相关矩阵改进的Pisarenko算法

Pisarenko算法是通过N个采样数据估计一个平稳随机信号参数的算法.改进的Pisarenko算法在噪声环境下可以精确估计信号频率.该算法通过一个时域累积量等式选择适当的数量关系得到新的自相关矩阵,最后利用最小二乘法求解得到频率的估计值.该算法把频域中提取的信号转换到时域中求解,从而避免了经典Pisarenko算法由于对自相关矩阵进行降维,使用样本自相关函数少,影响最后频率估计精度的缺点.仿真实验结果表明,所提的算法能够有效提高频率估计值的精度,频率估计性能稳定.