Spectral holography of pico- and nanosecond optical pulses

Recording and reconstruction of pico- and nanosecond pulses have been accomplished with spectral holography. The development of spectral holography in the nanosecond time-domain was achieved while using high-spectral-resolution equipment based on a Fabry-Perot etalon with a side entrance/exit. The recognition of the shaped nanosecond light pulses was also realized.     

无人机机载光电系统综述

本文主要介绍以色列、美国、俄罗斯、西欧诸国的无人机机载光电系统及其新技术的应用，如高精度稳瞄技术、美国的第四代电光相机、先进的前视红外系统及多光谱信息的压缩与传输技术。本文对我国无人机光电系统的设计有一定的参考价值。     

Spectral density estimation with amplitude modulation and outlier detection

This paper studies spectral density estimation based on amplitude modulation including missing data as a specific case. A generalized periodogram is introduced and smoothed to give a consistent estimator of the spectral density by running local linear regression smoother. We explore the asymptotic properties of the proposed estimator and its application to time series data with periodic missing. A simple data-driven local bandwidth selection rule is proposed and an algorithm for computing the spectral density estimate is presented. The effectiveness of the proposed method is demonstrated using simulations. The application to outlier detection based on leave-one-out diagnostic is also considered. An illustrative example shows that the proposed diagnostic procedure succeeds in revealing outliers in time series without masking and smearing effects. Supported by Chinese NSF Grants 10001004 and 39930160, and Fellowship of City University of Hong Kong.     

Normalizing transformations of some statistics of Gaussian ARMA processes

In this paper, the authors investigate Edgeworth type expansions of certain transformations of some statistics of Gaussian ARMA processes. They also investigate transformations which will make the second order part of the Edgeworth expansions vanish. Some numerical studies are made and they show that the above transformations give better approximations than the usual approximation.This work is supported by Contract N00014-K-0292 of the Office of Naval Research and Contract F49620-85-C-0008 of the Air Force Office of Scientific Research. The United States Government is authorized to reproduce and distribute reprints for governmental purposes notwithstanding any copyright notation hereon.The work of this author was done at the Center for Multivariate Analysis. His permanent address is Department of Mathematics, Hiroshima University, Naka-ku, Hiroshima 730, Japan.     

Spectral pollution

It is well known that routine methods of computing the spectrumof a self-adjoint operator often lead to spurious eigenvaluesin a gap between two parts of the essential spectrum. We providea geometrical explanation for a numerical method of resolvingthis problem, and give some examples of its use.     

Spectral smoothed boundary methods: The role of external boundary conditions

The spectral smoothed boundary method (SSBM) is a recently proposed numerical method to approximate the solution of partial differential equations in irregular domains with no‐flux boundary conditions by means of Fourier spectral methods. In this article we explore the robustness and accuracy of the scheme under variations of the artificial boundary conditions that must be imposed on the boundary of the enlarged domain in which the problem is solved. As a test model, we present quantitative numerical results based on a problem of propagation of waves of electrical activity in cardiac tissue for which the method is relevant. © 2005 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2006     

球面稳定同伦元素α1β1βs的非平凡性

决定球面稳定同伦群是同伦论中的核心问题之一, 是非常重要的. 该文证明: 球面稳定同伦元素α₁β₁β_s是一个阶为p的非平凡元素, 其中p ≥ 5是任意奇素数, 1≤ s     

Thermal imager primary design and analysis using PC based scientific spreadsheet

Effective primary design can avoid over-specification that will cause waste on cost. In this work, we propose a relatively simple procedure to rapid and reasonably write specifications, design systems and analyze requirements. The IR imager primary system design and analysis concepts adopt here are described. By using the primary design and analysis concept to cope with system performance models and PC based scientific spreadsheet to construct a mathematical software package which provides a costefficient, compliant solution to a design problem and predict thermal imager performance to an analysis problem. An illustrative example is presented to express more detail specifically due to the uncooled IR imager.     

高分子凝胶电解质及其在电色Smart窗中的应用

研究了高分子凝胶电解质高氯酸锂－碳酸丙烯酯－聚甲基丙烯酸甲酯体系（ＬｉＣｌＯ４－ＰＣ－ＰＭＭＡ）的离子导电性、导电机理以及在电色Ｓｍａｒｔ窗中的应用．其离子电导率与温度的关系服从Ｖｏｇｅｌ－Ｔａｍｍａｎｎ－Ｆｕｌｃｈｅｒ方程，并与体系的ＰＭＭＡ质量百分数、玻璃化温度（Ｔｇ）、碱金属盐的浓度等有关．当ＬｉＣｌＯ４浓度为０．５ｍｏｌ／Ｌ，ＰＭＭＡ＝３５％时，电解质具有良好的粘附性、光学透明度及较高的室温离子电导率（σ＝８．７５×１０－４Ｓ／ｃｍ）．由其组装成的全固态电色Ｓｍａｒｔ窗具有良好的光谱特性，可见光调制范围为４０％～６０％；具有良好的光开关特性，响应时间仅为５ｓ．     

Spectral characteristics of non-collinear acousto-optic tunable filters

The bandpass width and the diffraction efficiency of a non-collinear acousto-optic tunable filter are considered as functions of the optical wavelength for fixed values of the direction of propagation of the optic wave, the length of the acousto-optic interaction and the power density of the controlling RF-signal. A comparison between the calculated and the experimentally measured spectral dependencies is discussed and illustrated from the viewpoint of practical application for a TeO₂ filter. It is shown that in the approximation used, satisfactory agreement can be achieved between the experimental and calculated dependencies.