低温红外目标源控温技术

低温红外目标源是测试和标定低温红外传感器的响应线性度和非均匀性的关键测试设备.对所研制的低温红外目标源设备的工作原理进行了论述,同时基于有限元分析方法,以ANSYS 软件为载体对黑体面源控温方式及温度场分布进行模拟分析,并进行了测温实验.结果表明:所研制的低温红外目标源结构设计合理,仿真温度场与实测温度场分布规律一致,控温精度不大于0.5 K,黑体面源温度分布均匀,表面温差不大于0.2 K,稳定性好(0.1 K/min),可以满足低温红外系统的测试和检定要求.     

高稳定度激光光源数字温控技术

通过测量激光二级管(LD)制冷模块的响应曲线,采用曲线拟合的方法建立其数学模型,并针对该模型没计比例-积分-微分(PID)控制器控制LD的温度。实际测试证明该PID控制器能有效补偿制冷模块的相位延时,使LD的温度稳定度达到±0.05℃。     

非均匀温度场下红外热成像仪温控系统设计

为降低外界环境温度和内部发热元件形成的非均匀温度场对红外热成像仪的成像性能影响。通过Proe和Ansys ICEPARK建立红外热成像仪的有限元模型,在红外镜头表面进行黑色阳极氧化、喷砂处理增强辐射换热,以及安装风扇增强对流换热保证高温环境时的散热,低温环境时采用热电阻进行温升设计,并仿真分析红外热成像仪在不同温度环境下整机内部温度分布和红外镜头温度分布情况,并利用在高低温箱的红外热成像仪来观察平行光管中的靶标图的成像质量,验证温控设计的高效性。结果表明:所采用温度控制电路板对风扇与热电阻能进行温度控制,当环境温度下降至0℃和升高至30℃时,启动温控系统使红外热成像仪光学系统温度正常,保证红外热成像仪的成像质量。     

生物组织内红外热传递

结合热力学基本定律和热辐射理论,本文改进了Pennes生物热传导方程,来描述艾灸下生物组织内的热量传递过程。并采用Green函数法推导了其解析解,建立了定量解释艾灸下不同生物组织如健康组织、肿瘤组织的温度变化行为的方法。本文还提出温度衰减系数的概念来衡量组织内不同深度处的能量吸收情况。艾灸时皮肤表面温度的变化趋势与仿真结果的一致性验证实了方案的有效性。振荡的能量流对于组织来说是温和的刺激,这是生物组织实现良好功能的物理兴奋剂。结果表明,高频的能量主要被皮肤表层吸收,而低频的能量可以深入到生物组织内部。重要的是,疾病可以通过艾灸热的深透作用来治疗。     

An infrared scanning technique for the determination of temperature profiles in microcircuits

Circuit reliability and performance, particularly in high-density microcircuits, are affected by temperature. Therefore, a knowledge of the heat transfer paths and temperature distribution are of prime importance in topological design for efficient circuit performance. The method of thermal profiling described uses infrared scanning. The method is direct, rapid, and nondestructive, and the temperature profile is unaffected by the measurement. The effects of heat sinks, heat sources, and unusual geometrical patterns are automatically taken into account. The "heart" of the infrared scanning system is a photosensitive element of single-crystal indium antimonide with a long wave cutoff near 6 microns. The system has successfully determined isothermal patterns from 55°C to >250°C in thin-film tantalum microcircuits having linewidth patterns as small as 2 mils. Isothermal patterns of various geometries are shown to illustrate how the area and shape of resistors affect the thermal pattern and the temperature of the hottest part. Life data correlating the temperatures at the hottest parts with operating stability of thin-film resistive networks is presented. Through the correlation of temperature profiles with storage life tests, the potential exists for greatly reducing the amount of costly life testing of microcircuits for every new bias condition and circuit. Although emphasis is placed on thin-film microcircuits, a thermal profile of a solid silicon microcircuit is presented to indicate usefulness of the infrared scanning technique for temperature profiling of other types of microsystems.     

Decentralized optimal flow control with constrained source rates

We study optimal flow control in multiservice networks, in which users (controllers) optimize their performance objectives in a decentralized manner. We adopt a model that differs from previously considered ones in that a user's strategy (viz., flow or average rate) is constrained between two numbers: those are specified by the user's quality of service (QoS) requirements or by the user's technology. Adopting the generalized power as the performance measure, we prove existence and uniqueness of the Nash equilibrium point (NEP) and suggest a simple algorithm to determine this NEP     

An analytical quasi-saturation model considering heat flow for aDMOS device

This paper reports an analytical quasi-saturation model considering heat flow for a DMOS device. As verified by the PISCES results, the analytical model, which considers heat flow provides a good prediction of the much worse quasi-saturation behavior due to the elevated lattice temperature. This is a result of the limited heat sinking capability of the thermal contact node. Based on the analysis, for a DMOS device operating with a contact thermal resistance of less than 10⁴ K/W, the drain current at quasi-saturation is found acceptable with a lattice temperature below 350 K     

一种具有衬底温度补偿功能的非制冷红外读出电路

针对非制冷红外探测器系统,设计了一种无需衬底温度稳定器——热电制冷器(TEC)的读出电路(ROIC)结构.首先分析了衬底温度对微测辐射热计的特性的影响,利用ROIC对衬底温度变化引起的微测辐射热计的特性的变化进行补偿,实现ROIC的输出信号与衬底无关.该ROIC已在0.5 μm CMOS工艺下成功流片,并应用了到阵列大小为320×240的非制冷微测辐射热计焦平面上.测试结果表明:在衬底温度变化20 K时,ROIC输出信号仅变化2 mV,实现了去除TEC后衬底温度补偿的功能,有效地降低了系统功耗.该ROIC在低功耗,小体积的非制冷红外探测器上有着广泛的应用.     

激光辐照温度场计算中的"像热源"研究

激光热作用研究中 ,通常只能采用纯数值计算方法研究异形工件激光热处理温度场 ,本文介绍轴对称像热源处理边界问题的半解析计算方法并给出实验证明。该方法适用于任意分布光束的热作用计算 ,当工件的局部边界由非正交平面构成时 ,可以获得满意的计算结果     

掺铒光纤放大器泵浦光源温控系统设计

所描述的泵浦光源温控系统,以飞思卡尔的MC9S12系列MCU芯片作为开发平台,基于成熟的PID控制算法,大胆引入了闭环负反馈控制结构,它所输出的控制信号,不仅可以成功地驱动TEC电路,而且还可以使其在20s内将温度调控到目标值。在精度方面,达到了±0.1℃的工业级精度,完全满足设计指标的要求。     

SSRC:source rate control algorithm for delay-sensitive flow in data center network

Previous work had studied how to ensure the transmission time of delay-sensitive flows,but falled short in its effectiveness for a given period.Motivated by that and based on SDN/OpenFlow framework,a SDN-based source rate control (SSRC) algorithm was proposed.With a global view of network,SSRC can quickly locate the potential congestion node,adjust the transmission rate of source and reduce the response time of SSRC.The experiment results show that compared with DCTCP and other algorithms,SSRC can shorten the completion time of flows by 75% in average,which can ensure the transmission time of delay-sensitive and solve the problem of Incast well.     

Impact of nonlinear heat transfer on temperature control inregional hyperthermia

We describe an optimization process specially designed for regional hyperthermia of deep-seated tumors in order to achieve desired steady-state temperature distributions. A nonlinear three-dimensional heat transfer model based on temperature-dependent blood perfusion is applied to predict the temperature. Using linearly implicit methods in time and adaptive multilevel finite elements in space, we are able to integrate efficiently the instationary nonlinear heat equation with high accuracy. Optimal heating is obtained by minimizing an integral objective function which measures the distance between desired and model predicted temperatures. A sequence of minima is calculated from successively improved constant-rate perfusion models employing a damped Newton method in an inner iteration. We compare temperature distributions for two individual patients calculated on coarse and fine spatial grids and present numerical results of optimizations for a Sigma 60 Applicator of the BSD 2000 Hyperthermia System.     

卫星的表面温度与红外辐射特性

建立了卫星温度场与红外辐射特性的理论计算模型.首先利用有限元法求解瞬态热平衡方程,得到了卫星的温度场分布,然后根据卫星的表面温度分布,在3～6μm和6～16μm波段计算了卫星的红外辐射出射度,并对其变化规律及影响因素进行了详细的分析.最后将卫星视为空间点目标,计算比较了卫星处于日照区和地影区时两个波段的红外辐射强度空间分布.该研究结果对于空间目标的红外探测与识别具有参考价值.     

面向MEMS红外光源的辐射增强结构设计

针对常规TO封装下红外光源辐射量在一定光程下严重衰减的不足,基于自研的MEMS红外光源结构,提出了用于红外辐射增强的反射镜及用于光束准直的透镜封装结构,以期大幅提高光源有效辐射效率。本文基于Zemax软件对红外光源在光路中的辐射特性进行了模拟仿真。仿真结果表明:红外光源放置于9.52 mm口径、9.41 mm深度的抛物面反射镜的焦点位置,辐射能量提高了15.5倍;采用2.2 mm厚的BaF2材料的双凸曲面辐射透镜,红外光线呈准直收敛辐射,辐射效率最大可以达到27.42%。本工作研究成果为红外光学气体传感器光源提供了合理的红外辐射增强结构尺寸参数,有效提高了系统的稳定性和光源的辐射效率。     

红外产品用高洁高纯净高压氮气气源站设计

在导引头、探测器、位标器等红外用产品的测试过程中,高度依赖高纯高洁净高压气源,尤其对氮气的需求量是最大的,并且随着技术的发展,氮气的需求朝着高压力、高洁净、高纯度、低露点等方向拓展。由于红外制导所采用3~5μm、8~12μm波段的探测器,探测器需在70~100 K范围内的低温下工作(一般为80 K),以获得足够的灵敏度,所以低温制冷是这一类红外探测器不可缺少的重要条件之一,这就要求红外制导技术所采用的节流制冷器对氮气纯度有很高的要求,纯度一般需满足99.999%。本文针对氮气气源站的设计、气体纯化干燥、气源站监控、厂房建设、节能环保等方面,简要阐述了一套高纯高洁净红外用高压氮气气源站的设计方法,对各类气源站的设计提供了一定的指导意义。     

高帧频宽温度范围红外点源干扰装置设计

针对机动性能好、突防能力强的红外成像制导系统,利用极薄金属片可以快速加热升温与自然降温的特性,提出了一种适用于末制导阶段的新型红外干扰方法。建立了金属片加热升温及自然降温过程的数学模型,确定了金属片结构形式及材料特性;设计了结构简单、密封环境良好的红外点源干扰装置。试验结果表明:金属片优选2 μm厚的镍片,其加热时间为50 ms （500~1 000 ℃）,自然降温时间为75 ms （1 000~500 ℃）,可以满足帧频要求（10 Hz）;并实现了温度规律性的周期变化。分析与试验结果证实了红外点源干扰装置能够模拟红外辐射特性的快速变化,可为末制导阶段干扰提供一种新思路。     

一种用于车辆监控系统的红外探测装置

本文介绍了车辆监控系统中探测车辆到来的方法 ,并根据实际的要求 ,设计了一种成本低、电路简单、工作稳定、抗干扰性好的红外探测装置。本文的最后还分析了这种装置在应用过程中的一些问题。     

浅析演播室混合光源的色温与光圈控制

针对演播室高低色温光源混合运用造成的混合光场景录制节目所表现出来的图像画面色彩还原不理想,混合光色温变化不均匀一致造成画面颜色偏色以及怎样把控好光圈曝光量的问题进行了浅析.通过了解所用光源的特性,利用雷登纸来改变不同光源的色温使混合光场景的色温趋于相对一致,通过摄像机白平衡等技术的调整和与多部门的配合,通过了解镜头特性、把控光圈曝光量的大小来获得清晰、柔和、富有层次感图像,这样在混合光场景中就可得到满意的画面.