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111.
The development of biaxial segmental orientation and stress in a flexible-chain polymer fluid subjected to steady biaxial extensional flow is analyzed. Closed-formula model based on the Padè approximation of the inverse Langevin function in the non-Gaussian distribution of the chain end-to-end vectors is considered. The approach is free from the limitations related to finite chain extensibility and slow convergence of the series expansion formulations at higher chain deformations.Segmental orientation is characterized by the average orientation tensor, related axial orientation factors and global orientation anisotropy. Orientational behavior and corresponding stresses in the biaxial elongational potential flow are discussed in a wide range of elongation rates. Orientation characteristics calculated for the biaxial flow deformation are much higher than those predicted for the affine biaxial stretch deformation in polymer solids. 相似文献
112.
J. Martan N. Semmar C. Boulmer-Leborgne 《International Journal of Thermophysics》2007,28(4):1342-1352
An optical system for fast IR radiometry designed for investigations of thin film thermal properties and pulsed laser melting
was analyzed in this work. A methodology for determination of the view factor from calibration measurements was developed.
The view factor (0.0255) of the optical system containing two paraboloid mirrors was determined experimentally from calibration
measurements on pure metals and metallic alloys. The knowledge of the view factor was then applied to normal emissivity investigations
at IR wavelengths. The emissivity of tungsten films prepared by magnetron sputtering was determined for different deposition
conditions, varying between 0.036 and 0.071. Liquid phase emissivities of Cu, Mo, Ni, Si, Sn, Ti, and steel were also determined
and were found to be higher than solid-state emissivities as predicted from the literature. A knowledge of the liquid-state
emissivity of silicon enabled recalculation of the IR signal evolution to the temperature evolution, during and after a nanosecond
laser pulse. This was not possible by use of the usual calibration because of silicon’s semi-transparent behavior in the IR
range (1–10 μm) in the solid-state phase. 相似文献
113.
中国石化扬子石化股份公司烯烃厂2^#丁二烯装置使用某厂生产的44台ZE型离心泵。其机械密封使用寿命短,机封的小弹簧及辅助密封环在选材上存在一些问题。通过在实践中摸索与总结。对弹簧及密封环选用合适的材料,对原机封的结构进行改进,收到良好效果。 相似文献
114.
煤气设施防腐实践及影响质量因素分析 总被引:1,自引:1,他引:0
根据近几年三明钢铁公司煤气设施的防腐实践,就影响煤气设施的质量因素进行了分析。 相似文献
115.
化工企业环境因素的评价 总被引:1,自引:0,他引:1
化工企业环境因素评价是建立环境管理体系的核心任务,化工企业生产过程的特点决定了其环境因素数量多、环境影响大、识别评价难、控制难度大。本文介绍了化工企业环境因素评价的技术方法和过程,可以为提高环境因素评价的科学性、客观性和充分性提供参考。 相似文献
116.
A semi-Markov model is constructed that describes an arbitrarily structured multicomponent technological system and takes
into account its calendar maintenance. Using an aggregation algorithm, approximate values of stationary reliability characteristics
and an optimal term of maintenance work are determined for the system.
__________
Translated from Kibernetika i Sistemnyi Analiz, No. 2, pp. 69–86, March–April 2006. 相似文献
117.
Kenji Imura 《Color research and application》2007,32(3):195-200
In this article, a new method for measuring a total spectral radiance factor of a FWA‐treated sample illuminated by a specific standard illuminant is introduced. The method replaces an unstable real fluorescent standard by a bi‐spectral luminescent radiance factor data, which works as a virtual fluorescent standard (VFS) by knowing spectral intensity distributions of illuminations applied to the sample. The method utilizes two illuminations I1 and I2 whose relative spectral intensity distributions are different from each other and synthesizes a virtual illumination presenting the identical fluorescent spectral radiance factor to that presented by the standard illuminant with the VFS of the specific bi‐spectral luminescent radiance factor by linearly combining I1 and I2 with the suitable weighting factors. The applicability of the method is examined in principle by comparing ISO brightness and CIE whiteness index of fluorescent standard paper as a test sample obtained by this new method to the assigned values. © 2007 Wiley Periodicals, Inc. Col Res Appl, 32, 195–200, 2007 相似文献
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