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针对在高温燃烧环境中的颗粒辐射传热问题,基于普朗克辐射定律,提出了用于高温颗粒辐射传热参数在线测量的辐射光谱法,根据高温颗粒可见波段辐射光谱随波长变化情况,通过参数拟合方法直接获得颗粒温度及辐射强度等辐射传热参数。为验证该方法测量准确性,搭建了高温黑体炉辐射测量系统,实验测量结果显示:温度测量值与设定温度相对偏差小于3%;辐射强度测量值与理论计算值相对偏差小于5%。以此为基础,设计了应用于高温燃烧环境下的颗粒辐射传热参数测量的水冷结构探针,并利用该探针开展了高温燃烧环境气固两相流200~1 100nm波段辐射光谱测量,基于上述方法,直接获得了高温颗粒温度、辐射强度等辐射传热参数沿截面分布情况,有效剥离了高温气体对流传热的影响,为高温颗粒辐射传热研究提供数据支撑。 相似文献
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针对在高温燃烧环境中的颗粒辐射传热问题,基于普朗克辐射定律,提出了用于高温颗粒辐射传热参数在线测量的辐射光谱法,根据高温颗粒可见波段辐射光谱随波长变化情况,通过参数拟合方法直接获得颗粒温度及辐射强度等辐射传热参数。为验证该方法测量准确性,搭建了高温黑体炉辐射测量系统,实验测量结果显示:温度测量值与设定温度相对偏差小于3%;辐射强度测量值与理论计算值相对偏差小于5%。以此为基础,设计了应用于高温燃烧环境下的颗粒辐射传热参数测量的水冷结构探针,并利用该探针开展了高温燃烧环境气固两相流200~1 100 nm波段辐射光谱测量,基于上述方法,直接获得了高温颗粒温度、辐射强度等辐射传热参数沿截面分布情况,有效剥离了高温气体对流传热的影响,为高温颗粒辐射传热研究提供数据支撑。 相似文献
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Measurement accuracy analysis of the free carrier absorption determination of the electronic transport properties of silicon wafers 下载免费PDF全文
By introducing the random and systematic errors in simulated data computed from conventional frequency-scan and laterally resolved modulated free carrier absorption theory models, we investigate the relative determination sensitivities of three electronic transport properties, namely, carrier lifetime, carrier diffusivity and front surface recombination velocity of silicon wafers determined by frequency-scan and laterally resolved techniques. The phase and amplitude data with random errors as functions of the modulation frequency at zero pump-probe-beam separation or of the two-beam separation at four different modulation frequencies are simultaneously fitted to an appreciated carrier diffusion model to extract three transport parameters. The statistical results and fitted accuracies of the transport parameter determined by both techniques are theoretically analysed. Corresponding experimental results are carried out to compare to the simulated results. The simulated and experimental results show that the determination of the transport properties of silicon wafers by the laterally resolved technique are more accurate, as compared with that by the frequency-scan technique. 相似文献
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In this paper, we study n-Gorenstein projective modules over Frobenius extensions and n-Gorenstein projective dimensions over separable Frobenius extensions. Let R ■ A be a Frobenius extension of rings and M any left A-module. It is proved that M is an n-Gorenstein projective left A-module if and only if A ■RM and HomR(A, M) are n-Gorenstein projective left A-modules if and only if M is an n-Gorenstein projective left R-module. Furthermore, when R ■ A is a separable Frobenius extension, n-Gorenstein projective dimensions are considered. 相似文献
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一、高中生学习数学的现状、心理和习惯1.少数学生视数学为畏途,是一门枯燥乏味的科目.一部分学生认为数学就是不停的讲题目、做题目,毫无新意可言.2.学习方法不当.许多学生没有学习计划,课前不预习,对学习的新内容不了解,因而上课忙于笔记,错过了重点和难点的分析和思考;课后又不能及时巩固、总结,只是依照笔记本套题型,解题没有章法,不能掌握问题的实质. 相似文献
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In the Gorenstein homological theory, Gorenstein projective and Gorenstein injective dimensions play an important and fundamental role. In this paper, we aim at studying the closely related strongly Gorenstein flat and Gorenstein FP-injective dimensions, and show that some characterizations similar to Gorenstein homological dimensions hold for these two dimensions. 相似文献
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