Analysis of Spacecraft Relative Motion and Applicability of Hill's Solution

研究了空间飞行器编队中最具基础性的问题之一,即相对运动的解析表达及Hill���程的适用条件。通过建立相对运动的通解公式,针对不同性质的初值深入地分析了其相对运动轨迹的本质特征,并给出了Hill���程的适用条件。此外,文中还给出了一个新的编队设计简化公式。

Hill Instability Analysis Of Tlp Tether Subjected To Combined Platform Surge And Heave Motions

This paper presents the Hill instability analysis of Tension Leg Platform (TLP) tether it, deep sea. The 2-D nonlinear beam model which is Undergoing Coupled axial and transverse vibrations, is applied. The governing equations are reduced to nonlinear Hill equation by use of the Galerkin's method and the modes superposition principle. The Hill instability charted Lip to large parameters is obtained. An important parameter M is defined and can he expressed as the functions of tether length, the platform surge and heave motion amplitudes. Some example studies are performed for various environmental conditions. The results demonstrate that the nonlinear coupling between the axial and transverse vibrations has a significant effect on the response of structure.. It needs to be considered for the accurate dynamic analysis of long TLP tether subjected to the combined platform surge and heave motions.

Extending Tsai-Hill and norris criteria to predict cracking direction in orthotropic materials

methods of lifetime measurement are discussed.

航天器相对运动与Hill���的适用性分析

研究了空间飞行器编队中最具基础性的问题之一，即相对运动的解析表达及Hill���程的适用条件。通过建立相对运动的通解公式，针对不同性质的初值深入地分析了其相对运动轨迹的本质特征，并给出了Hill���程的适用条件。此外，文中还给出了一个新的编队设计简化公式。

Hit-or-miss representation of a pattern spectrum and its optical implementation

We demonstrate that a pattern spectrum can be decomposed into the union of hit-or-miss transforms with respect to a series of structure-element pairs. Moreover we use a Boolean-logic function to express the pattern spectrum and show that the Boolean-logic representation of a pattern spectrum is composed of hit-or-miss min terms. The optical implementation of a pattern spectrum is based on an incoherent optical correlator with a feedback operation. (C) 1996 Optical Society of America

垂直腔面发射激光器与MISS���电开关集成

Submitted by zhangdi (zhangdi@red.semi.ac.cn) on 2009-04-13T11:45:31Z

Photonic switch and NOT logic gate based on the hybrid integration of a GaAsVCSEL and a GaAs MISS

The hybrid integrated photonic switch and not logic gate based on the integration of a GaAs VCSEL (Vertical Cavity Surface Emitting Lasers) and a MISS (Metal-Insulator-Semiconductor Switches) device are reported. The GaAs VCSEL is fabricated by selective etching and selective oxidation. The Ultra-Thin semi-Insulating layer (UTI) of the GaAs MISS is formed by using oxidation of A1As that is grown by MBE. The accurate control of UTI and the processing compatibility between VCSEL and MISS are solved by this procedure. Ifa VCSEL is connected in series with a MISS, the integrated device can be used as a photonic switch, or a light amplifier. A low switching power (10 mu W) and a good on-off ratio (17 dB contrast) have been achieved. If they are connected in parallel, they perform a photonic NOT gate operation.

Photonic AND Gate Based on Hybrid Integration of GaAs VCSEL and GaAs MISS

于2010-11-23批量导入

GaAs VCSEL/MISS���合集成光子开关

报道了MBE生长的GaAs材料VCSEL与MISS���合集成构成的光子开关。将MBE生长的超薄AlAs层氧化为A_xO_y层用作MISS���件的超薄半绝缘层，从而解决了该半绝缘层厚度的精密控制以及与VCSEL工艺相容的问题。该集成器件除光子开关功能外，还能实现光放大功能，并可用于自由空间光互连。