反潜巡逻机雷达巡逻搜潜的面积等效模型

针对反潜巡逻机使用雷达巡逻搜潜问题,首先给出了雷达搜索概率模型,不仅分析了雷达搜索扫描宽度,而且综合考虑了潜艇是否暴露、能否规避两个重要因素。在此基础上,通过分析反潜巡逻机巡逻线阵位、相对运动关系,采用面积等效法,建立了适用于一般情况的巡逻搜潜探测概率模型。最后,仿真分析了搜索时间、巡逻线长度与阵位位置等因素对雷达探测概率的影响。结果表明,面积等效模型可较好地解决反潜巡逻机巡逻搜潜的概率计算问题;反潜巡逻机使用雷达巡逻搜潜时,发现概率随搜索时间的延长而增加,但最后趋于一定值,且最大发现概率不高。     

基于潜艇航向均匀分布的多舰检查搜潜建模与仿真

基于舰艇舰壳声纳搜潜原理及实际搜潜方法的研究,对多舰协同由内向外和外向内两种平行搜索方法进行了研究,建立了两种搜索方法的数学模型,给出潜艇航速恒定、航向变化及航速变化、航向变化的运动模型。基于潜艇航向服从均匀分布的假设条件,采用蒙特卡洛方法,仿真得到在两种潜艇运动模型下,两种搜索方法对潜艇的搜索概率及搜索到潜艇的平均时间,给出潜艇航向变化时间间隔对搜索概率的影响,并对两种搜索方法的搜潜效能进行了分析比较。     

正态圆分布下的双机吊放声纳扩展方形搜潜建模

针对反潜直升机吊放声纳搜潜概率计算问题,在分析扩展方形搜潜法的基础上,提出了对称扩展方形搜潜法。并且,以双机使用吊放声纳搜潜为例,以目标位置服从正态圆分布为条件,采用解析法建立了对称扩展方形搜潜概率计算模型。同时,针对已探测区不出现目标的面积会随时间衰减的事实,对搜索概率计算模型作了修正。最后,仿真计算了搜索高、低速两类目标下的搜索概率,结论是:搜索低速目标时,对称扩展方形具有更高的发现概率;而对于高速目标,两种方法的搜索概率都较低,难以满足反潜要求。     

机载搜索雷达搜潜作用距离实时预报模型

为了满足航空反潜指挥控制系统对雷达搜潜效能进行实时预测评估的需要,文中在分析海况对雷达作用距离影响的基础上,提出了基于海洋环境变化的雷达探潜作用距离实时预报模型。由模型得出的雷达作用距离与海况的关系基本符合实际情况,预报结果能够用于雷达搜潜效能的实时评估。     

反潜直升机武器挂载方案研究与仿真

反潜直升机在任务规划期间,优化武器挂载方案是提高反潜直升机搜攻潜效能的有效途径.通过建立反潜直升机搜攻潜效能数学模型,分析任务执行期间可能的作战模式和它们的效率及代价,给出不同预设搜潜模式下的典型武器挂载方案,辅助任务规划人员进行决策.仿真表明,所提出的武器挂载规划方法具备经验法简单实用的优点,同时还量化了搜索时间、搜索面积、搜索和攻击概率等指标,方便任务规划人员进行决策.     

机载红外探测仪检查搜潜建模与仿真

依据经典的检查搜潜方法,结合实际的搜潜过程,以某型反潜巡逻机为背景,建立了反潜巡逻机执行平行航线搜潜、外旋扩展方形搜潜和内旋扩展方形搜潜时航路规划的数学模型和潜艇运动模型.对3种检查搜潜方法的搜潜效能进行了分析,并对初始距离、搜潜海域面积、潜艇经济航速和海洋大气环境对检查搜潜效能的影响进行了仿真.实验结果表明:初始距离...     

浮标阵搜潜建模仿真与潜艇逃逸结果分析

通过构建应召反潜作战中典型包围阵的航路模型、潜艇模型和固定翼反潜机模型等多个模型,实现了潜艇逃逸和布放声呐浮标阵搜潜的仿真建模,并对反潜距离、潜艇航速、搜潜阵型等要素对搜潜效能的影响进行仿真实验研究。在此基础上,针对高搜潜概率下,搜潜失败时的潜艇逃逸方向概率分布进行了分析,得到不同阵型的搜潜方向性特征属性。     

磁探仪应召螺旋搜潜航路规划建模与仿真研究

针对磁探仪应召螺旋搜索的特点,运用随机搜索理论定量分析了反潜巡逻机利用磁探仪进行螺旋搜索时的搜潜效能。根据飞行气象学中风对飞行影响的描述,结合潜艇运动规律的特点,建立了反潜巡逻机使用磁探仪执行螺旋搜索时的航路模型,并以反潜巡逻机与潜艇初始位置、反潜巡逻机航速和航向、风速和风向等为条件,经蒙特卡罗仿真分析,得到了潜艇速度已知和未知条件下,磁探仪搜索概率、搜索时间随潜艇位置散布和潜艇速度变化的情况。该航路模型既考虑了反潜巡逻机机动性能的限制,也考虑了海洋环境对反潜机的影响,较好地符合实际作战环境,满足磁探仪应召搜潜训练的要求。     

基于先验目标分布的被动浮标阵布放半径分析

根据被动浮标阵应召搜潜过程,运用概率论和最优搜潜理论对浮标阵的布放半径进行研究.综合考虑浮标阵应召搜潜时潜艇初始位置、航速和航向等分布的特点,建立了浮标阵发现潜艇概率的数学模型,据此推导出使发现潜艇概率最大的布放半径(称之为改进的布放半径).建立了反潜直升机布放典型浮标阵的搜潜模型,根据搜潜模型利用蒙特卡罗对搜潜效能进行仿真分析.结果表明:利用数学模型计算得到的发现潜艇概率与通过蒙特卡罗仿真得到的发现潜艇概率基本一致;与利用经典的布放半径布放浮标阵相比,利用改进的布放半径布放浮标阵能提高发现潜艇概率,且所需浮标数量少.     

直升机声纳浮标包围阵搜潜模型研讨

介绍了直升机声纳浮标包围阵的典型阵型,建立了其浮标位置模型,为浮标阵的实际布放提供科学的理论依据。建立了潜艇初始位置散布模型,给出了潜艇位置散布半径的计算方法。然后,基于一定的假设条件,对潜艇最大航速进行了估计,将两倍的经济航速作为潜艇的最大航速,并从概率的角度验证了该结论的合理性,此时,潜艇的速度服从瑞利分布。最后,对潜艇初始位置散布以及潜艇经济航速对直升机声纳浮标包围阵搜潜概率的影响进行了仿真分析,得出了仿真结果。     

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.