热式空气流量传感器设计

在燃油喷射发动机系统中，需对空燃比进行控制，控制的依据则为发动机的进气流量。本文介绍一种热式空气流量传感器的设计和典型应用。     

汽车电子燃油喷射系统发展动向

汽车电子燃油喷射系统发展动向汽车电子燃油喷射系统（简称ＥＦＩ）是用计算机控制发动机燃油供应量的装置，可以同时解决节油和尾气排放两大难题。在计算机控制下，ＥＦＩ能根据车速、环境温度、发动机转速等一系列参数，自动对发动机进行燃油喷射控制、空－燃比控制、全...     

基于矩阵束算法的极点提取分析

目标极点特征具有目标姿态不敏感性以及明晰的物理意义,是雷达目标识别研究的重点和热点方向之一。为了实现目标极点的准确提取,提出了目标极点数目已知及未知情况下,奇异值分解参数的确定方法,并以实例验证了方法的有效性;通过对不同信噪比的噪声信号进行极点、留数提取及误差分析,探究了矩阵束算法抑制噪声的能力。仿真结果表明,矩阵束算法对信噪比为10 dB的噪声信号进行极点提取时仍具有较高的精确度。     

一种基于ARMA模型的目标极点提取新方法

针对传统极点提取算法需要确定目标后时响应起点的不足,本文提出了一种提取目标极点的新方法,该方法使用ARMA模型逼近整个目标响应,并利用全局最小二乘技术求解模型参数获取目标极点。基于实测细导线和有限长柱体散射场数据的处理结果表明,本文新方法较之KT法和矩阵束法具有更高的极点提取精度。     

利用遗传算法求取雷达目标极点分布

散射物体自然频率(极点)是目标识别可以利用的一个基本特征,传统的理论求解极点的方法一般是用迭代法求取由矩量法得到的矩阵方程系数行列式的零点.矩阵方程系数矩阵的病态性是其最大的缺点.文章提出了用遗传算法获得极点的方法,对遗传算法应用于求取雷达目标极点方面的问题做了理论和算法分析.由于球体目标的极点可以解析获得,所以利用了球体作为实验验证的例子.并计算了有限长圆柱的结果.实验结果表明算法相对于传统的围线积分法不仅避免了病态矩阵的问题,而且简单易行,结果可靠.     

一种雷达目标极点提取方法及极点特性的分析

散射物体复自然谐振频率(极点)是目标识别可以利用的一个重要特征。使用传统求解极点的方法,通常得到的极点数目比较多,并且存在TE、TM两种模式。因此,对极点的规律分析较多的是对其模式变化趋势的分析。这些特性对于极点的实际应用没有太大的意义。本文从频率矩量法得到的散射数据出发,提出了一种波形拟合的极点提取方法。以有限长柱和椭球为例。分析了极点与入射波模式、目标姿态的关系,得到有实际指导意义的结论。     

基于极点聚焦全极点滤波器减小LCD运动模糊的方法

提出一种基于极点聚焦技术的减少LCD运动模糊效应的方法,通过建立二维全极点滤波器,采取分块处理方法对视频信号进行处理,并采用模拟仿真的方法进行实验评估,结果表明极点聚焦全极点滤波器对于减小LCD的运动图像模糊具有一定的效果,尤其是在图像高频出现的地方效果明显.所提出的方法具有算法简单,便于硬件实现的优点.     

任意形状导体目标的极点求解

从理论上求解极点,频域矩量法结合围线积分是通用且准确的方法,但由于计算量大而一直用于处理旋转对称目标的求解.本文提出Chebyshev多项式展开格林函数的方法,把频率因子从电场积分方程中分离出来,实现了多频点矩量法的快速计算,解决了任意形状导体目标极点的求解问题.最后对围线积分方法进行适当改进,并求解了三种目标的极点.     

光滑目标表面不连续性极点分布规律研究

利用雷达目标散射场极点分布特征来进行目标识别具有重要的理论意义.用矩阵束法对导体球和圆柱体散射场进行极点提取,分析了当光滑导体球与圆柱体表面存在局部凸起和凹陷时,极点分布的变化规律.结果发现,当光滑导体球和圆柱体局部存在凸起时,和无凸起情况相比,极点的虚部变小;当光滑表面存在局部凹陷时,极点虚部变大.     

压电分流阻尼电路设计的极点配置方法

针对作为被动控制的压电分流阻尼电路提出极点配置方法。对压电分流阻尼系统建立机电耦合方程,考虑模态位移为输出量,得到系统极点的特征方程。运用主导极点与虚轴的距离对系统动态响应衰减有着关键作用这一特性,确立优化目标,然后求解出压电分流阻尼电路参数的最优值。最后通过数值仿真对所设计的优化方法进行检验,并与传统传递函数优化法进行比较。仿真结果表明,运用极点配置方法设计的压电分流电路有着良好的抑制振动的效果,这验证了极点配置方法的有效性。     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.     

GaAsSb/InAlAs PA DHBTs Grown by Production MBE

The epi material growth of GaAsSb based DHBTs with InAlAs emitters are investigated using a 4 × 100mm multi-wafer production Riber 49 MBE reactor fully equipped with real-time in-situ sensors including an absorption band edge spectroscope and an optical-based flux monitor. The state-of-the-art hole mobilities are obtained from 100nm thick carbon-doped GaAsSb. A Sb composition variation of less than ± 0.1 atomic percent across a 4 × 100mm platen configuration has been achieved. The large area InAlAs/GaAsSb/InP DHBT device demonstrates excellent DC characteristics,such as BVCEO＞6V and a DC current gain of 45 at 1kA/cm2 for an emitter size of 50μm × 50μm. The devices have a 40nm thick GaAsSb base with p-doping of 4. 5 × 1019cm-3 . Devices with an emitter size of 4μm × 30μm have a current gain variation less than 2% across the fully processed 100mm wafer. ft and fmax are over 50GHz,with a power efficiency of 50% ,which are comparable to standard power GaAs HBT results. These results demonstrate the potential application of GaAsSb/InP DHBT for power amplifiers and the feasibility of multi-wafer MBE for mass production of GaAsSb-based HBTs.     

Technology innovation and process integrations for sub-100nm gate patterning

This paper presents a brief overview of the Applied Centura(R)DPS(R)system,configured with silicon etch DPS Ⅱ chamber, with emphasis on discussing tuning capability for CD uniformity control. It also presents the studies of etch process chemistry and film integration impact for an overall successful gate patterning development. Discussions will focus on resolutions to key issues, such as CD uniformity, line-edge roughness, and multilayer film etching integration.     

White organic light-emitting devices based on fac tris（2- phenylpyridine） iridium sensitized 5,6,11,12-tetraphenylnap -hthacene

We have fabricated the white organic light-emitting devices （WOLEDs） based on 4,4＇ -bis（2,2 -diphenyl vinyl）-1,1＇ - biphenyl （DPVBi） and phosphorescence sensitized 5,6,11,12,-tetraphenylnaphthacene （rubrene）. The device structure is ITO/2T-NATA （20 nm）/NPBX （20 nm）/CBP： x%Ir（ppy）3：0.5% rubrene （8 nm）/NPBX （5 nm）/DPVBi （30 nm）/Alq（30 nm）/LiF（0.5 nm）/A1. In the devices, DPVBi acts as a blue light-emitting layer, the rubrene is sensitized by a phosphorescent material, fac tris （2-phenylpyridine） iridium [Ir（ppy）3], acts as a yellow light-emitting layer, and N,N＇ -bis- （1-naphthyl）- N,N＇ -diphenyl -1, 1＇ -biphenyl-4,4＇ -diamine （NPBX） acts as a hole transporting and exciton blocker layer, respectively. When the concentration of Ir （PPY）3 is 6wt%, the maximum luminance is 24960 cd/m^2 at an applied voltage of 15 V, and the maximum luminous efficiency is 5.17 cd/A at an applied voltage of 8 V.     

Complete approach to automatic identification and subpixel center location for ellipse feature

To meet the need of automatic image features extraction with high precision in visual inspection, a complete approach to automatic identification and sub-pixel center location for similar-ellipse feature is proposed. In the method, the feature area is identified automatically based on the edge attribute, and the sub-pixel center location is accomplished with the leastsquare algorithm. It shows that the method is valid, practical, and has high precision by experiment. Meanwhile this method can meet the need of instrumentation of visual inspection because of easy realization and without man-machine interaction.     

小角度扩展相关性近似算法分析

本论文提出一种在多天线MIMO信道相关性建模中小角度扩展近似理论算法,并应用于分析MIMO系统性能。分析中分别对三种不同角能量分布情况下的空间相关性研发快速近似计算法,并同时提出双模(Bi-Modal)角能量分布情况下的近似运算。通过分析这些新方法的近似效率,可以得到计算简单、复杂度低、而且符合实际的MIMO相关信道矩阵,对系统级的快速高效计算法的研究和系统级的评估以及误差分析具有重要的意义。     

Noise character analysis and the restraint of self-pulsation laser diodes

We calculate the Langevin noise sources of self-pulsation laser diodes, analyze the effects of active region noise and saturable-absorption region noise on the power fluctuation as well as period fluctuation, and propose a novel method to restrain the noise effects. A visible SIMULINK model is established to simulate the system, The results indicate that the effects of noise in absorption region can be ignored; that with the increase of DC injecting current, the noise effects enhance power jitter, and nevertheless, the period jitter is decreased; and that with external sinusoidal current modulating the self-pulsation laser diode, the noise-induced power jitter and period jitter can be suppressed greatly. This work is valuable for clock recovery in all-optical network.