用于OADM的集成声光可调谐滤波器的性能分析

利用模式耦合理论分析了声光模式转换.并对声光可调谐滤波器的滤波带宽、调谐范围、驱动功率等性能参数进行了分析计算.设计制作滤波器时,首先在保证滤波带宽的前提下,考虑调谐范围、驱动功率以及加工工艺的要求.对其应用于OADM中存在的旁瓣和串扰问题进行了初步讨论.设计完成中心波长在1.55 μm,滤波带宽为1.2 nm左右,波长调谐范围大于150 nm,低驱动功率的IAOTF.     

我国商业银行应大力发展个人理财业务

分析了商业银行发展个人理财业务的重要性，介绍了该项业务在我国的现状，提出了应采取的策略。     

一种自学型远程教学系统的设计

自主学习是远程教学中的一种重要的学习方式，自学型远程教学系统是一种基于自学模式为主的远程教学系统。本主要从系统环境、系统的软件结构两个方面来阐述自学型远程教学系统的设计。     

An integrated optical TE-TM mode splitter

A hybrid technology developed for the deposition in planar waveguides of a multilayer which controls the guided optical power by interference has been tested using a TE-TM mode splitter as an example. The preparation of waveguides which exhibit good edge properties, the deposition of the multilayer and the mutual alignment of the waveguides by better than λ/5 are described. The ratio of the transmitted TE power to the reflected TM power has been measured to be 0.9±0.1, which agrees well with the 1.0 yielded by theory. Distortion due to mode conversion, TE reflectance and TM transmittance is of the order of 1%.     

Predicting the mode of flow in pneumatic conveying systems-A review

An initial prediction of the particulate mode of flow in pneumatic conveying systems is beneficial as this knowledge can provide clearer direction to the pneumatic conveying design process.There are three general categories of modes of flow,two dense flows:fluidised dense phase and plug flow,and dilute phase only.Detailed in this paper is a review of the commonly used and available techniques for predicting mode of flow.Two types of predictive charts were defined:basic particle parameter based (e.g.particle size and density) and air-particle parameter based (e.g.permeability and de-aeration).The basic particle techniques were found to have strong and weak areas of predictive ability,on the basis of a comparison with data from materials with known mode of flow capability.It was found that there was only slight improvement in predictive ability when the particle density was replaced by loose-poured bulk density in the basic parameter techniques.The air-particle-parameter-based techniques also showed well-defined regions for mode of flow prediction though the data set used was smaller than that for the basic techniques.Also,it was found to be difficult to utilise de-aeration values from different researchers and subsequently,an air-particle-based technique was developed which does not require any de-aeration parameter in its assessment.     

麻黄素拉曼散射振动模式的研究

利用显微拉曼对违禁药品麻黄素以及伪麻黄素———左旋咪唑致幻药物做了拉曼测试 ,在激发光 5 1 4 5nm和室温环境下 ,得到了麻黄素和左旋咪唑分子的拉曼散射谱。麻黄素属单取代苯类 ,具有Cy2ν对称性 ,我们对它的拉曼振动模式做了识别。并将麻黄素的拉曼谱和甲基安非他明做了对比分析 ,麻黄素和甲基安非他明同属单取代苯 ,其分子结构十分相似 ,由于取代基的成分不一样 ,因而拉曼谱中一些峰的相对强度和位置发生了变化     

用于较大泵浦尺寸半导体泵浦固体激光器的一种特殊腔型

提出一种泵浦固体激光器的特殊腔型,解决了当功率较大时泵浦尺寸较大使得泵浦光斑与激光光斑不匹配的问题,并从激光腔理论和速率方程理论两方面通过数值计算验证了该腔型的优越性.同时对LD泵浦固体激光器以及倍频的设计提出了几条普适原则.     

井巷位置设计与经济效益研究

研究了井巷掘进直接成本数学模式,以此进行井巷位置的优化设计和选择,以求达到最佳经济效益。     

基于二次EEMD的转子故障信号时频分析方法研究

HHT时频分析被广泛应用于机械故障诊断中,但其模态混叠成为应用时的瓶颈。针对此问题提出了利用二次集合经验模态分解分解(ensemble empirical mode decomposition,EEMD)来消除模态混叠的时频分析方法。该方法首先用EEMD将原信号分解成若干个本征模函数(intrinsic mode function,IMF),然后选取相关系数较大的分量重构原信号,再利用EEMD对其进行二次处理,便可获得去除模态混叠的时频分布。通过对仿真与实验转子信号分析,该方法可以有效抑制经验模式分解(empirical mode decomposition,EMD)的模态混叠现象,相比一次EEMD,二次EEMD去除模态混叠更明显,能有效应用于旋转机械故障诊断中。     

Origin and System Effects of Polarization Mode Dispersion in Chirped Bragg Gratings

Polarization mode dispersion of chirped Bragg gratings is analyzed in terms of key birefringence phenomena and impact on telecommunication systems performance. The influence on polarization mode dispersion (PMD) of fiber birefringence, grating chromatic dispersion, and ripples of the group delay curve is pointed out. Polarization mode dispersion influence on systems performance is investigated by numerical simulations and transmission experiments at 10 Gbit/s. The deterministic nature of Bragg gratings PMD determines a moderate, upper-limited system penalty for a transmission line employing a single compensating device. However, in the case of broadband components, a non-negligible PMD penalty may be observed due to the difficulty of controlling accurately the group delay linearity.