恒热流边界条件下降膜温度场及其对红外探测距离的影响

深入分析了利用恒热流边界条件下下降液膜（降膜）技术对军事目标垂直进行红外抑制的方法。建立了层流降膜的流动与传热模型,采用能量守恒法,忽略液膜入口段效应,得到了降膜表面的温度分布,简化了求解过程。通过与不同研究者结果做对比,验证了能量守恒法对于评估降膜在充分发展段换热过程的有效性。计算了探测器对采用液膜红外抑制技术后目标的识别距离,结果表明:增大液膜流动的流量、合理控制液膜入口温度可增强对特定目标的红外抑制效果。本人的研究方法和结论对军事目标的红外抑制领域具有中重要的参考意义。     

微热板式低气压传感器的研制

研制了一种采用CMOS工艺和表面牺牲层技术加工的微热板式低气压传感器．该微热板为四臂支撑悬空矩形板，其边长为75μm，支撑桥长为60μm，板下气隙高度为0.5μm．采用经典傅里叶传热理论分析了恒电流工作方式下气压对微热板瞬态和稳态热特性的影响，结果表明在低气压范围内微热板传热以支撑桥导热为主，气压较高时以气体导热为主，微热板加热功率随气压增加而减小；传感器的热响应时间为毫秒量级并随气压增加而减小．传感器采用恒电流工作方式时，测得其气压响应范围为1～10~5Pa，且加热功率与气压间关系的理论分析结果与实测值吻合得较好．     

多晶硅膜及其薄发射极退火特性的研究

本文详细研究了退火方式和条件对多晶硅膜结构、电性能以及多晶硅接触薄发射极的发射极电阻的影响。结果表明，１０００℃以上热退火对于减小发射极电阻、降低多晶硅膜的电阻率有利；激光退火不但能减小发射极电阻，导致更低的多晶硅膜电阻率，而且还能获得极浅的单晶发射结，在改善薄发射极晶闸管特性方面显示出较大优势。     

TFT-LCD中周边显示不均改善研究

本文研究了周边显示不均发生机理,从生产工艺方面提出PI边缘大液滴、加速PI液蒸发、涂布后环境风速降低等PI边缘膜厚偏薄改善的有效对策,改善了周边显示不均的不良.     

双波长动态液膜厚度与温度同步测量系统

基于半导体激光吸收光谱(DLAS)技术,研制了双波长动态液膜厚度与温度高精度同步测量系统。利用标准具对该系统的测量精度进行验证。结果表明,该系统的液膜厚度和温度的平均测量误差分别为4.58%和1.34%。在此基础上,利用该系统对水平石英玻璃板上的液膜蒸发过程进行研究。结果表明,液膜的平均蒸发速率为0.34μm/s,蒸发速率随液膜温度的升高而增大,且DLAS与图像法和热电偶测得的结果吻合良好。利用该系统对流道中的动态液膜进行研究,在不同液膜温度(308,315,323 K)下,液膜平均厚度基本一致且在1 s内波动11次,液膜温度几乎保持恒定。     

基于TDLAS技术在线测量气流道内液膜动态厚度

在液膜厚度测量时,通过选取液态水吸收截面不同的两个波长可消除除液态水吸收以外的其他信号衰减所造成的影响,如轻微的光束转向现象。但该方法仍较难消除在液膜蒸发过程后期由于液膜收缩所造成剧烈的光束转向现象的影响。基于双波长可调谐半导体激光吸收光谱(TDLAS)技术测量透明石英玻璃板上液膜蒸发过程中膜厚的变化,并同时用图像法追踪液膜形状的变化,对剧烈的光束转向现象进行研究。在此基础上,通过在光电探测器前放置积分球,对已有的TDLAS液膜测量系统进行优化,以消除剧烈光束转向现象对膜厚测量的影响,并利用该系统分别测量了气流道内液膜形成过程和蒸发过程中液膜的厚度变化。     

过冷降膜的温度场及红外隐身应用研究

深入分析了利用定常温度下过冷降膜技术对军事目标进行红外隐身的方法。建立了层流降膜的流动与传热模型,采用积分法得到了降膜表面的温度分布,提高了解的精度。对比不同研究者的结果与实验值,得到了液膜自由表面温度变化主要是由热边界层厚度与液膜厚度关系、初始温度、液膜流量、动力粘度的变化引起的。计算了不同参数下过冷降膜对军事目标的红外抑制效果,结果表明:过冷降膜是一种简单有效的红外抑制技术,增大液膜流动的流量、降低液膜入口温度或增加物体粘性均可增强对特定目标的红外隐身效果,该技术在军事目标的红外隐身方面应用前景广阔。     

超薄LPCVD二氧化硅膜栅介质

本文介绍低温生长的薄LPCVD二氧化硅膜经短时间热退火后，热氮化后的物理及电学性质。与热生长二氧化硅膜性质进行比较，结果表明，LPCVD二氧化硅膜许多性质优于热生长二氧化硅膜。适合做MOS晶体管的栅介质。文中重点指出，小于10nm的超薄的LPCVD二氧化硅膜经快速热退火或热氮化后做MOS晶体管的栅介质，其电学特性优于热生长二氧化硅膜做栅介质的MOS晶体管。在低温器件及超大规模集成电路中有广泛的应用前景。     

1064 nm倍频波长分离膜的制备与性能研究

通过对主膜系添加匹配层并借助计算机对膜系进行优化，设计出结构规整、性能优良的1064ilm倍频波长分离膜。用电子束蒸发及光电极值监控技术在K9玻璃基底上沉积薄膜，将样品置于空气中在260℃温度下进行3h热退火处理。然后用Lambda 900分光光度计测量了样品的光谱性能；用表面热透镜(STL)技术测量了样品的弱吸收值；用调Q脉冲激光装置测试了样品的抗激光损伤阈值(LIDT)。实验结果发现，样品的实验光谱性能与理论光谱性能有很好的一致性。退火前后其光谱性能几乎没有发生温漂，说明薄膜的温度稳定性好；同时退火使样品的弱吸收减小，从而其激光损伤阈值提高。理论和实验结果均表明，对主膜系添加匹配层的方法是1064nm倍频波长分离膜设计的较好方法。     

SAW叉指换能器的铝蒸发条件

本文介绍适用于SAW叉指换能器的最小合用铝膜厚度.为获得高性能SAW器件和实现精密设计起见,千兆赫SAW器件的叉指换能器宜采用较薄的铝膜.文中展示了蒸发期间各种基片温度参数的铝膜电阻率和膜厚之间的实验关系,指出了最佳蒸发条件.     

两种微型热管传热性能对比研究

以波形脉动热管和微槽平板热管为研究对象,基于Mixture模型构建了其三维非稳态数学模型,并对模型可靠性进行了验证。采用该数学模型对比了两种微型热管在相同散热空间和散热热流密度情况下的热阻、平均壁面温度和蒸发段壁面温度均匀性。结果表明:相对于微槽平板热管,波形脉动热管热阻更低,传热性能更好;波形脉动热管蒸发段稳态平均壁面温度更低,且随着热流密度的增加该优势更加明显;波形脉动热管在空间尺度上蒸发段壁面温度均匀性更好,且这种优势在高热流密度情况下更突出,但这种均匀性在时间尺度上变化相对剧烈。     

Measurement of thin liquid film thickness in pipes based on optical interferometry

Accurate measurement of the thin liquid film thickness in pipes is the foundation for studying the characteristics of the film. In this paper, an interferometry-based measurement of liquid film thickness in transparent pipes is developed, which can greatly improve the accuracy, extend the lower limit of measurement and provide a new technical approach for the calibration and traceability. The light intensity distribution is established based on the optical path analysis and a mathematical model....     

激光窗口杂散光固气耦合热效应对光束质量的影响

为实现激光传输内通道密封,会在末端加装带倾斜角的窗口,但窗口的回射杂散光辐照管壁会引起结构温升,加热通道内气体引起热效应。针对密封窗口的回射杂散光辐照加热直管道问题,建立了直管道部分结构场-气体密度场-光场的耦合仿真模型,分析了不同管道材料、管壁厚度、管道结构形式对光束波前畸变的影响。分析结果表明:等质量的铝、铜、钢三种材料中,铝管道引起的光束波前畸变最小,仅为钢、铜的约50%;通过管道外侧增加散热翅片以及高导热碳膜的方式来降低壁温、改善波前畸变的效果并不理想,波前RMS值下降不超过3%;增加受辐照段管道壁厚、提升管道热沉是降低光束波前畸变最有效的方案,铝管壁厚由8 mm增加至16 mm可使管道出口处的波像差RMS值从36.1 nm下降到21.4 nm,各阶像差均得到改善。研究结果能够为内通道部分管道设计和热效应评估提供一定的参考。     

Non-contact inspection for inner surface of small-diameter pipes based on laser-PSD

Small diameterpipesareusedwidelyinmanyfields, suchasenergyindustry,chemicalindustry,aviation,weaponmanufacturingandsoon.Theinspectionof thesepipesisveryimportantbecauseofthebadworking conditions.Therearemanymethodstoinspectthepipeswithinnerdiameterslargerthan20mm,suchasthe wholecircleimagemethod[1],theringopticalcutting imagemethod[2],thelaser beamscanningdisplacementmeasuringtechnique[3],theCCTVcameramethod[4], Omni directionalmethod[5]etc.Butfewmethodscande tectthepipeswithaninnerdiameter…     

尺寸效应下超快激光加热硅薄膜二维传热研究

超快激光技术目前较为广泛地应用于微纳米结构的加工,极小的尺寸产生了不同于宏观条件的传热特性,也逐渐成为人们研究的热点。文章采用改进双相滞导热(dual-phase-lagging,DPL) 模型对超快激光照射纳米硅薄膜的二维传热过程展开了理论研究。通过应用积分变化法求解了反映尺寸效应的改进DPL方程,分析了薄膜内部温度沿薄膜厚度方向和径向的变化规律。结果显示薄膜加热区域的温度迅速升高,随后能量会以波的形式逐渐向薄膜内部传递。在采用改进DPL模型得到的结果中热量的波状传递现象与DPL模型的结果相比更为平缓,将二维改进模型的结果同一维结果进行对比,发现在相同克努森数下,二维模型得到的温度要高于一维模型;且两者的差距会随着时间的推移愈发明显,表明二维传热过程中热量的径向传递对薄膜内部的温度分布具有重要影响。     

杂质微粒对薄膜的损伤效应

激光对光学薄膜的损伤仍然是限制高能激光系统的主要挑战。对杂质诱导薄膜损伤的激励进行了研究:首先对损伤形貌进行了观测,在此基础上对杂质对薄膜的作用效应进行了分析。研究结果表明:杂质粒子对薄膜产生的各种效应,主要分为热力学效应、散射引起干涉效应和激光等离子体破坏效应,这三种效应的共同作用效果决定了损伤的特点。这些作用效应与粒子的半径密切相关:当粒子较小时,激光的沉积量较少,引起邻近材料的温升较低,扩散范围较小,主要是熔化破坏;当粒子较大时,激光沉积量较多,会引起邻近光学材料的汽化和电离,形成激光等离子体而造成大的烧蚀坑。     

A Study on Thermal Performance of Heat Pipe for Optimum Placement of Satellite Equipment

A study on the operation of a heat pipe with two heat sources has been performed to optimize the heat distribution of satellite equipment. A numerical modeling is used to predict the temperature profile for the heat pipe assuming cylindrical two-dimensional laminar flow for the vapor, and the conduction heat transfer for the wall and wick. An experimental study using the copper-water heat pipe with the length of 0.45 m has been performed to evaluate the numerical model and to compare the temperature distribution at the outer wall for the non-uniform heat distribution. The results on temperature profiles for the heat input range from 29 W to 47 W on each heater are presented. Also the correlation between the heat input and the temperature increase is presented for the optimum distribution on two heaters. The result shows that the outer wall temperature can be controlled by redistribution of heat sources. It is also concluded that the heat source closer to the condenser can carry more heat while maintaining lower temperatures at the outer wall.     

Condensation Induced Delamination of Nanoscale Hydrophobic Films

Vapor condensation is a crucial phenomenon governing the efficiency of many processes. In particular, dropwise condensation on hydrophobic thin films (≈100 nm‐thick) has the potential to achieve remarkable heat transfer. However, the lack of durability of these thin films has limited applications for a century. Although degradation due to steam condensation has been described as “blistering,” no satisfactory insight exists capable of elucidating the driving force for film delamination. Here, it is shown that nanoscale pinholes in hydrophobic films are the source of blister formation. By creating artificial pinholes via nanoindentation on thin (30 to 500 nm‐thick) fluorinated hydrophobic films, it is demostrated that water blisters can be initiated at the pinholes during condensation. It is experimentally demonstrated that vapor is transferred to the blister through the nanoscale pinhole, and the driving force for delamination is capillary pressure generated at the pinhole by the pinned liquid–vapor interface. The techniques and insights presented here will inform future work on polymeric thin film and enable their durable design for a variety of applications.     

Preparation of Self‐Organized Mesoscale Polymer Patterns on a Solid Substrate: Continuous Pattern Formation from a Receding Meniscus

Regular polymer patterns are formed from casting a dilute polymer solution on a solid substrate. Dissipative structures, e.g., convection patterns, fingering instabilities, and so on, are formed in the evaporation process of casting polymer films. Controlled production and manufacturing of patterned polymer films can be achieved when the evaporating solution edge, especially the meniscus region on the casting substrate, is formed under controlled casting conditions. In this report, we describe a computer‐controlled apparatus which has two precisely manipulated sliding glass plates. A narrow, thin liquid film of polymer solution with a receding meniscus is continuously supplied from a small gap between two glass plates (one sliding and the other stationary), and a patterned polymer film is subsequently formed on the stationary substrate from the evaporating solution edge. Several types of polymer patterns from various polymers are reproducibly prepared by changing preparation conditions such as sliding speed and polymer concentration.     

Design and Simulation of the Thin Film Pulse Transformer

A new thin film pulse transformer for using in ISND and ADSL systems has been designed based on a domain wall pinning model, the parameters of nano-magnetic thin film such as permeability and coercivity can be calculated. The main properties of the thin film transformer including the size,parallel inductance, Q value and turn ratio have been simulated and optimized. Simulation results show that the thin film transformer can be fairly operated in a frequency range of O.OO l-2O MHz.