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991.
研究了梯度折射率半透明介质内的辐射传递,采用弯曲光线跟踪法和伪 光源迭加法推导出一侧为灰壁面另一侧为镜反射半透明界面,具有线性折射率分布的发射-吸收性半透明介质层内的辐射强度。通过与文本的精确方法进行比较,进一步验证了以往对该类问题采用分层处理的可靠性。 相似文献
992.
在大量试验基础上,系统分析和总结了宽级配冰碛土在高应力状态下应力—应变关系和强度特性、影响计算模型参数值的主要因素。结合砾石土宽级配土料(风化料、冰碛土)的变形强度机理,提出了新的非线性K—G模型及其验证和应用 相似文献
993.
994.
995.
Emerging challenges to structural integrity technology for high-temperature applications 总被引:1,自引:0,他引:1
Tu Shantung 《Frontiers of Mechanical Engineering in China》2007,2(4):375-387
Structural integrity technology has been widely used with great success for the design, manufacture and failure prevention
of modern constructions such as chemical and petrochemical plants, power generation and energy conversion systems, as well
as space and oceanic exploration. The modern needs of structural integrity technology are largely attributed to the increase
of service temperature of the structures that results in the efficiency improvement in energy conversion and chemical processing
technologies. Besides the needs arising from large-scale high-temperature plants, the high tech developments, such as micro
chemo-mechanical systems and high-power electronics, provide new challenges to structural integrity technology. The present
paper summarizes the recent technical progresses in large process plants and the aviation industry, micro chemo-mechanical
systems, fuel cells, high-temperature electronics, and packaging and coating technologies. The state-of-the-art of structural
integrity technology for high temperature applications is reviewed. Suggestions are provided for the improvement of current
design and assessment methods. 相似文献
996.
997.
Long Jeffrey D.; Harring Jeffrey R.; Brekke John S.; Test Mary Ann; Greenberg Jan 《Canadian Metallurgical Quarterly》2007,19(3):298
Longitudinal validity of Brief Symptom Inventory subscales was examined in a sample (N = 318) with schizophrenia-related illness measured at baseline and every 6 months for 3 years. Nonlinear factor analysis of items was used to test graded response models (GRMs) for subscales in isolation. The models varied in their within-time and between-times parameter constraints, with the homogeneous model being the least constrained, followed by the 2-parameter GRM and 1-parameter GRM. Results show that 4 subscales (Interpersonal Sensitivity, Hostility, Paranoid Ideation, Psychoticism) were consistent with the 1-parameter GRM, and 5 subscales (Somatization, Obsessive-Compulsive, Depression, Anxiety, Phobic Anxiety) were consistent with the 2-parameter GRM. There is evidence that the 9 subscales may be validly used to study change in single constructs over time. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
998.
999.
针对新建H铁路沿线基床表层填料十分匮乏的问题,对H铁路路基表层填筑A组土和级配碎石比选进行了技术经济分析比较,并针对全线不同地段选择了不同的填料方案,从而节省了工程投资。 相似文献
1000.
In the present paper, a finite crack with constant length (Yoffe type crack) propagating in the functionally graded strip
under the plane loading is investigated by means of the Schmidt method. By using the Fourier transform and defining the jumps
of displacement components across the crack surface as the unknown functions, two pairs of dual integral equations are derived.
To solve the dual integral equations, the jumps of the displacement components across the crack surface are expanded in a
series of Jacobi polynomial. Numerical examples are provided to show the effects of the material properties, the thickness
of the functionally graded strip, and speed of the crack propagating upon the dynamic fracture behavior. 相似文献