Analysis of Center Wavelength Shift of VCSEL Light in AWG for WDM PON Applications

Center wavelength shift of vertical cavity surface emitting laser light in arrayed waveguide gratings is verified with mathematical and experimental analysis.It is induced by the linearly increasing trend of optical power of vertical cavity surface emitting laser by bias current increase.It is retrieved effectively to the original center wavelength by simple correction method of compensation.This was done for application of vertical cavity surface emitting laser as a light source in optical line terminal of wavelength division multiplexing-passive optical network.     

An armature structure for 3D shapes

We present a novel armature structure for 3D articulated shapes, called SBall short for skeletal balls, which includes two parts： a one-dimensional skeleton and incident balls. Our algorithm mainly focuses on constructing the armature structure. This structure is based on an approximation skeleton which is homotopy equivalent to the shape. Each ball in the structure connects a skeletal joint and an interior region of the shape. The boundary vertices on the shape surface are attached onto the SBall using the power diagram of the ball set. A bilateral O~tering algorithm and a variational segmentation algorithm are proposed to enhance the quality of SBall. Finally, applications of this structure are discussed.     

Geometric height inequalities and the Kodaira--Spencer map

We extend a result of Vojta on height inequalities for algebraic points oncurves over function fields to include the case of positivecharacteristic. The main tool used is the Kodaira--Spencer map anddestabilizing flags for vector bundles on curves.     

SOLUTION OF COUPLED ACOUSTIC PROBLEMS: A PARTIALLY OPENED CAVITY COUPLED WITH A MEMBRANE AND A SEMI-INFINITE EXTERIOR FIELD

There have been many attempts to understand the coupling phenomena between a solid structure and the surrounding fluid. However, the studies were restricted to interaction only between a structure and a finite cavity or a structure and acoustic field of infinite size. The system that we have studied has a structure that faces both a cavity of finite size and an external field of semi-infinite size. We also allow a hole, which can directly interact with the cavity as well as the external field. This configuration, therefore, provides two different interactions, or communication means. One is the finite structure and the other is the hole of finite size. This paper studies as to how these two components interact with the other two systems: the finite cavity covered by the structure and the hole, and the semi-infinite fluid. For simplicity, a two-dimensional and partially opened cavity coupled with a membrane and an exterior field was selected. The solution has to be found by solving a boundary value problem, but this case has to do with the boundaries that have two different conditions: one is the membrane and the other is the hole. The solution has been found in terms of the modal functions that satisfy the boundary conditions of finite cavity, membrane and hole. Non-dimensional coupling coefficients are obtained from the solution. The results exhibit that the coupling effect gives additional peaks and troughs in the averaged pressure of the cavity. These peaks and troughs are symmetrically arranged with respect to Helmholtz frequency of the cavity. The strong coupling occurs at the trough frequencies where the membrane interacts actively with the cavity and the exterior field.     

Influence of parasitic couplings in bending sections on directional coupler optical switching

The modified switching conditions of directional coupler optical switches, in the presence of parasitic couplings in bending sections, are discussed by means of the coupled mode theory. As expected, a parallel section's length needs to be adjusted by less than the coupling length lc (=pi/2kappa0), depending on the amount of parasitic coupling. For weak parasitic coupling, however, the switching voltage does not need to be altered but maintains the same value as without parasitic coupling.     

有向图覆盖的Zeta函数

Mizuno和Sato定义了有向图的Zeta函数(见Linear Algebra Appl.,2001,336:181-190),它可用来计算有向图中具有给定长度的所有圈的个数.给出了任意有向图的覆盖的Zeta函数的计算公式.作为推论,覆叠重数为2,3和4的任意有向图覆盖(正则或非正则)的Zeta函数被计算出来,同时也计算了Cayley有向图的Zeta函数.     

A SIMPLE MODEL TO ESTIMATE THE IMPACT FORCE INDUCED BY PISTON SLAP

The dynamics of piston's secondary motion (lateral and rotational motion) across the clearance between piston and cylinder inner wall of reciprocating machines are analyzed. This paper presents an analytical model, which can predict the impact forces and vibratory response of engine block surface induced by the piston slap of an internal combustion engine. A piston is modelled on a three-degree-of-freedom system to represent its planar motion. When slap occurs, the impact point between piston skirt and cylinder inner wall is modelled on a two-degree-of-freedom vibratory system. The equivalent parameters such as mass, spring constant, and damping constant of piston and cylinder inner wall are estimated by using measured (driving) point mobility. Those parameters are used to calculate the impact force and for estimating the vibration level of engine block surfaces. The predicted results are compared with experimental results to verify the model.     

全光纤调Q掺铒光纤激光器的脉冲研究

报道一种全光纤调Q掺铒光纤激光器,在其结构中采用带有光纤光栅的光纤环形镜作为调Q装置此调Q方案同时具有对腔内损耗进行调制和对激光输出波长选择的功能理论上分析了不同臂长差时的脉冲出现情况,与实验基本相符并对激光单脉冲产生及稳定性进行了分析讨论.     

Ce0.8Sm0.2O1.9的尿素燃烧法合成与性能

采用以尿素为燃料的燃烧合成法制备Ce0.8Sm0.2O1.9(SDC)氧离子导体材料, 对燃烧合成粉体的物相和显微形态进行了表征, 并研究了燃烧法合成SDC的烧结性能以及烧结体的导电性能. 研究结果表明, 采用尿素燃烧法合成SDC具有简便高效和合成粉体烧结活性高的优点. 经过燃烧过程后即可得到立方萤石结构的纯相SDC粉体, 合成粉体的分散性良好, 为50~150 nm的球形颗粒, 具有高的烧结活性, 在1250 ℃的烧结温度下, 陶瓷样品的相对密度可达到95.1%. 在600和800 ℃的测试温度下, 烧结温度为1250 ℃的陶瓷样品的电导率分别达到5.4×10-2和1.0×10-1 Ω-1·cm-1.     

Controllable Ultra Low- k by Via-Typed Air Gap with the Better Design Margin for Logic Devices below 45nm Node

By changing the air gap to a via-typed air gap, the height of the air gap is reduced up to about 50% compared to the height of the trench-typed air gap. The controllable （1 ≤h 〈 2.9） ultra low-k is also easily fabricated by adjusting the space of the via-typed air gap. The via-typed air gap makes the design margin better due to its lower height in the dense and narrow lines.