Analysis of the detectivity for triple-layer heterojunction GaSb/GaInAsSb infrared detectors

In this paper, the detectivity is calculated and analyzed with the front-or backside illuminated case for both N-GaSb/p₂-Ga_0.8In_0.2As_0.19Sb_0.81/p₁-Ga_0.9In_0.1As_0.09Sb_0.91 and N₁-GaSb/n₂-Ga_0.9In_0.1As_0.09Sb_0.91/p-Ga_0.8In_0.2As_0.19Sb_0.81 infrared photovoltaic detectors, respectively. The analysis results show that the main absorption appears in the p-type Ga_0.8In_0.2As_0.19Sb_0.81 material with either front- or backside illuminated case for above two structures. In each structure, the carrier concentration obviously affects the detectivity. The carrier concentration in the wide-bandgap material for the isotype heterojunction should be reduced as low as possible to reduce the tunneling rate at the isotype heterointerface. Moreover, the change of the detectivity with the p-side surface recombination velocity for the N₁-n₂-p structure is more sensitive than that with the p₁-side surface recombination velocity for the N-p₂-p₁ structure. In the N-p₂-p₁ structure with the incident light from the p₁-side surface, two-color detection is achieved.     

Analysis and observation of backscatter-induced crosstalk in a 2-DFDM fiber gyro system

The modulation characteristics of first-order backscatter-induced crosstalk noise in a 2-D frequency-division-multiplexed fiber gyro system are analyzed and experimental results presented. The noise can be reduced from 5°/h to 0.2°/h (0.25 NEB) by proper choice of modulation depth and/or frequency     

镁合金表面喷铝防腐蚀层的微观组织分析

在AZ91D镁合金表面热喷铝，用以提高其表面的耐腐蚀性能。采用SEM，EPMA等方法对AZ91D表面喷铝扩散层的组织进行了仔细的观察与分析，发现在防腐蚀层上有大量的Mg17Al12相存在，且呈决状及非连续片状分布。经显微硬度测定，喷铝层硬度较镁合金基体高；腐蚀后这种相凸出于基体，比镁合金基体有较好的耐腐蚀性能。     

基于ASP.NET的校园网上商店的研究与实现

本文分析了校园网上商店建设的背景,提出了建设校园网上商店的必要性。运用ASP.net技术,提出了校园网上商店的商业模式分析、体系结构、平台设计方案和实现方法。     

Application of model predictive control strategy based on fuzzy identification to an SP-100 space reactor

In this work, a model predictive control method combined with fuzzy identification, is applied to the design of the thermoelectric (TE) power control in the SP-100 space reactor. The future TE power is predicted by using the fuzzy model identified by a subtractive clustering method of a fast and robust algorithm. The objectives of the proposed fuzzy model predictive controller are to minimize both the difference between the predicted TE power and the desired power, and the variation of control drum angle that adjusts the control reactivity. Also, the objectives are subject to maximum and minimum control drum angle and maximum drum angle variation speed. The genetic algorithm that is effective in accomplishing multiple objectives is used to optimize the fuzzy model predictive controller. A lumped parameter simulation model of the SP-100 nuclear space reactor is used to verify the proposed controller. The results of numerical simulations to check the performance of the proposed controller show that the TE generator power level controlled by the proposed controller could track the target power level effectively, satisfying all control constraints.     

重点建设工程档案管理工作探讨

针对重点建设工程档案的管理现状,提出了明确岗位责任、加强制度建设以及夯实基础工作的档案管理理念。     

A knowledge-based system for sensor selection

This paper presents a Knowledge-based system (KBS) developed to allow users, who may not be knowledgeable about sensors, to select sensors suitable for their specific needs. The KBS runs on a micro-computer. The selection criteria are user specified and are based on the desired measurement parameters. The system output includes all of the operational and dimensional parameters of the recommended sensor, price, and vendor information.     

New concept of surface modification to LiCoO2

As the continuance of our series study on LiCoO₂ surface modification, the complicated traditional surface coating method is replaced with simple addition of amorphous YPO₄ and Al₂O₃ in commercial LiCoO₂ or in commercial electrolyte based on our understanding to the improvement mechanism of surface modification. Comprehensive studies by X-ray photoelectron spectroscopy (XPS), gas chromatography and mass spectroscopy (GC–MS), inductively coupled plasma (ICP) and Fourier transformed infrared (FTIR) indicate that the products of spontaneous reaction between the additive and the LiPF₆ based electrolyte are responsible for the performance improvements.     

环境资源负外部性与产权理论的新进展

环境资源共有产权的特性使得社会成员只能通过自身感知和理解确定对环境资源的产权边界，并且产权的实施是非排他的，所以与环境资源有关的负外部性较其他具有直接因果关系的外部性特殊。在治理这类负外部性的过程中，产权理论也有了新的发展。本文从分析环境资源产权的特殊性入手，对于产权弱化、产权分割、创建新产权和自愿合作基础上认知产权调整等负外部性内部化理论进行了分析。     

太阳能热管的研制和应用

介绍了太阳能热管发展的社会背景和历史沿革、太阳能热管单管的工质选择和管壳结构、热管式真空集热管的结构特点及太阳能热管在热水器中的应用