双台阶式埋氧SGOI自加热效应的数值研究

To reduce the self-heating effect of strained Si grown on relaxed SiGe-on-insulator(SGOI) n-type metal-oxide-semiconductor field-effect transistors(nMOSFETs),this paper proposes a novel device called double step buried oxide(BOX) SGOI,investigates its electrical and thermal characteristics,and analyzes the effect of self-heating on its electrical parameters.During the simulation of the device,a low field mobility model for strained Si MOSFETs is established and reduced thermal conductivity resulting from...     

Temperature-Aware Electromigration Analysis with Current-Tracking in Power Grid Networks

Electromigration (EM) is a severe reliability issue in power grid networks.The via array possesses special EM characteristics and suffers from Joule heating and current crowding,closely related to EM violations.In this study,a power grid EM analysis method was developed to solve temperature variation effects for the via array EM.The new method is based on the temperature-aware EM model,which considers the effects of self-heating and thermal coupling of interconnected lines in a power grid.According to the model,the proposed methodology introduces a locality-driven strategy and current tracking to perform full-chip EM assessment for multilayered power grids.The results show that temperature due to Joule heating indeed has significant impacts on the via EM failure.The results further demonstrate that the proposed method might reasonably improve efficiency while ensuring the accuracy of the analysis.     

Dynamic surface temperature measurements in SiC epitaxial power diodes performed under single-pulse self-heating conditions

Semiconductor devices development, design and optimization require the use of computer simulation tools able to predict the entire device safe operating area (SOA), something that it is not always possible due to limitations in some of the physical models in predicting certain properties of device operation under extreme conditions (i.e. high carrier injection levels and high temperature). In order to improve our understanding of device operation under these extreme conditions experimental data of the dynamic IV characteristics and temperature time evolution and space distribution are required. The experimental data obtained are then used in the development of improved physical models and simulation tools.

In this work, dynamic surface temperature measurements as a function of current pulse peak density and length were performed on SiC-PiN epitaxial power diodes. The measurements were carried out using an infrared (IR) microscope developed in our lab capable of measuring space and time surface temperature distributions in semiconductor devices operating under self-heating conditions [Solid State Electron 2001;45(12):2057]. The minimum detected spot size is 15 μm, while the signal raising time is detector limited to about 1 μs. The lowest detectable temperature increment is at least 10 °C over room temperature.

Using this instrument, dynamic thermal phenomena in 4.5 kV SiC-PiN epitaxial power diodes [Mater Sci Forum 2001;353–356:727] subjected to 1 ms long 100–6000 A/cm² and 0.1–5 ms long 3000 A/cm² current pulses have been studied. The possibility of obtaining dynamic surface temperature information from SiC electronic devices operating under self-heating conditions with time constants in the order of ms is demonstrated.     

低周疲劳损伤过程的自热温升变化特征

通过对低周疲劳过程中试样的自热温升红外测试,讨论了不同控制应变下,试样的温升变化规律及其表面的温度分布与循环数、控制应变水平及加载频率的关系。探讨了循环疲劳损伤与温升变化的对应关系及其能量变化规律。     

气相色谱-质谱法测定自热食品接触用塑料制品所用着色剂中14种多氯联苯

该文建立了同时测定自热食品接触用塑料制品所用着色剂中的14种多氯联苯的气相色谱-串联质谱法。样品中的多氯联苯经有机溶剂超声提取,用浓硫酸磺化,气相色谱-串联质谱法分析,外标法定量。结果表明,14种多氯联苯在质量浓度为0.5~5 µg/L的范围内均线性良好,相关系数(R2)均大于0.99。14种多氯联苯的检出限均为5 μg/kg,定量限均为25 μg/kg。当添加量为5、10、 25 µg/kg时,14种多氯联苯在荧光红中的回收率为81.03%~105.72%之间,相对标准偏差(RSD)在1.51~10.52之间;在荧光黄中的回收率为80.11%~108.44%之间,RSD在0.69~11.10之间;在荧光蓝中的回收率为81.07%~102.56%之间,RSD在0.72~10.80之间;在荧光绿中的回收率为80.26%~109.37%之间,RSD在1.12~11.41之间;在荧光紫中的回收率为80.15%~105.80%之间,RSD在1.21~10.89之间。该方法快速准确,能够为自热食品接触材料着色剂安全性评价作技术参考。     

低碳型自热式牛奶包装盒的研制

目的:利用氧化钙和水发生化学反应产生热量来研制可自动快速加热牛奶的新型包装盒。方法:通过单因素实验比较不同氧化钙和水的比例、不同材质包装和不同启热方式对加热牛奶效率的影响。结果:氧化钙和水分别为40g和60g时、外包装盒为纸质材料、消费者自行注水的加热效率最好,且牛奶初始温度为10℃时,可在4min内使牛奶温度达到43℃,保温7min。结论:本研究提供了一种可自动快速加热牛奶的纸质包装盒,其结构简单、操作简单,而且体积小、质量轻。     

自发热货物标准测试方法对偶氮类染料粉末适用性

摘 要：在海上运输过程中,自发热物质是造成海运事故最多的原因之一。鉴别货物是否属于自发热物质的方法,是采用联合国《关于危险货物运输的建议书试验和标准手册》中的标准测试方法N.4。标准测试方法N.4是基于“热篮法”模型,同时参考碳类物质自发热规律发展而来的。标准方法N.4对偶氮类染料的适用性缺少相关验证数据。通过对偶氮类染料粉末的自发热现象进行探究,发现“热篮法”模型可用于描述偶氮类染料的自发热过程;偶氮类染料的自发热反应活化能为129.6 J/mol;标准测试方法N.4不适用于偶氮类染料可能出现“假阳性”的误判。建议相关标准测试方法或管理法规,对自发热特性得到充分研究的化学品货物给予更为精细的管理,以减少资源的浪费和经济的损失。     

湿煤堆非稳态温度场计算

本文利用计算机编辑对湿煤堆非稳态自热过程的一维模型进行差分计算,求得不同煤层厚度湿煤堆内的非稳态温度场。结果表明,采用自热过程的非稳态数学模型计算,可以剖析影响湿煤堆自热的因素。     

Room temperature-initiated and self-heating copolymerization of acrylonitrile with vinyl acetate

A novel polymerization method [Ruckenstein and Li, Polymer Bull., 37, 43 (1996)]—room temperature-initiated, self-heating polymerization—was applied to both bulk and concentrated emulsion copolymerization of acrylonitrile (AN) with vinyl acetate (VAc). A redox system was employed as an initiator, with the oxidant dissolved in the monomers and the reductants (two reductants were employed) in the aqueous phase. In the bulk polymerization, the oxidant (cumene hydroperoxide) was dissolved in the mixture of monomers, and the two reductants (sodium metabisulfite and ferrous sulfate) were introduced as an aqueous solution. In the concentrated emulsion polymerization, a mixture of the monomers containing dissolved oxidant was first used as the dispersed phase of a concentrated emulsion in water, and the aqueous solution of reductants was subsequently added to the concentrated emulsion. In both cases, the polymerization started at room temperature, just after the reductants were introduced. Because the reactor was insulated, the heat generated by the reaction was mostly used to accelerate the polymerization, which reached a high conversion in 30 min. The effects of various parameters on the polymerization were investigated. Optimum values were found for the volume fraction of the dispersed phase, for the wt ratios of the two reductants and of the oxidant to reductants, and for the surfactant and reductant concentrations. One concludes that the concentrated emulsion polymerization method is particularly suitable for the room temperature-initiated, self-heating polymerization. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68: 999–1011, 1998