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761.
This work deals with the chemical grafting of a styrene maleic anhydride copolymer on the surface of a previously hydrolyzed polyethylene terephthalate (PET) film 12 μm thick via covalent bond. Two different ways are studied. The first one involves an activation of the hydrolyzed PET by the triethylamine before the grafting step. In the second one, the copolymer reacts with the 4-dimethylaminopyridine in order to form maleinyl pyridinium salt which reacts with alcohol function of the hydrolyzed PET. Characterization and quantification of the grafting are performed by Fourier transform infrared spectroscopy. Factorial experiment designs are used to optimize the process and to estimate experimental parameters effects. The opportunity to associate the chemical process to a cold remote nitrogen plasma one is also examined. 相似文献
762.
763.
This paper presents a new method for maximizing manufacturing yield when the realizations of system components are dependent random variables with general distributions. The method uses a new concept of stochastic analytic center introduced herein to design the unknown parameters of component values. Design specifications define a feasible region which, in the nonlinear case, is linearized using a first-order approximation. The resulting problem becomes a convex optimization problem. Monte Carlo simulation is used to evaluate the actual yield of the optimal designs of a tutorial example. 相似文献
764.
765.
复消色差的短波红外望远物镜设计 总被引:2,自引:1,他引:1
分析计算了一些普通光学玻璃及晶体光学材料在0.9~2.5 μm短波红外段的色散特性.在远距型的物镜结构后组中采用的厚弯月镜能产生一定量的反向色差补偿前组中的二级光谱,所设计的物镜在焦距800 mm时的带孔径处最大色差0.13 mm.结果表明,采用氟化物玻璃与重火石玻璃的三片式组合在短波红外段具有较好的消色差能力. 相似文献
766.
均匀设计优化共振瑞利散射法测定水中阴离子表面活性剂 总被引:3,自引:1,他引:2
在均匀设计优化后的反应条件下,研究了含吩嗪结构类染料健那绿(JG)与十二烷基苯磺酸钠(SDBS)作用的共振瑞利散射光谱,建立一种简便快速的环境水样中阴离子表面活性剂(AS)均匀设计优化共振瑞利散测定新方法。在pH12.4时,加入SDBS导致JG共振瑞利散射剧烈增强,在λem=λex=625nm处,存在一共振瑞利散射峰,其强度与SDBS的浓度呈线性关系,方法的线性范围为0—3.48mg·mL^-1,检出限为17.8ng·mL^-1。方法简便、快速,与单因素轮换法实验结果比较,实验条件更优化,可直接用于测定环境水样中的阴离子表面活性剂。 相似文献
767.
C. Skrobol T. Heindl R. Krücken A. Morozov R. Steinhübl J. Wieser A. Ulrich 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,54(1):103-109
The 1.73 μm XeI laser has been operated in a fully continuous mode
using a table-top electron beam pumped laser setup. A 12 keV electron beam
sent through a 300 nm thick silicon nitride membrane into a laser gas
mixture of typically 600 mbar gas pressure was used for pumping. A low loss
cavity was installed, resulting in a very low pumping power of 37 mW to
reach laser threshold. The geometrical conditions for the laser setup such
as the shape of the beam pumped volume and its overlap with the optical mode
volume are discussed. The laser scheme has been clearly identified as a
recombination laser scheme by operating the laser in pulsed mode and
observing the time structure of the laser pulse. 相似文献
768.
769.
Christopher L. Rumsey Thomas B. Gatski W. Kyle Anderson Eric J. Nielsen 《International Journal of Heat and Fluid Flow》2001,22(6):573-582
An adjoint optimization method is utilized to design an inviscid outer wall shape required for a turbulent flow field solution of the So–Mellor convex curved wall experiment using the Navier–Stokes equations. The associated cost function is the desired pressure distribution on the inner wall. Using this optimized wall shape with a Navier–Stokes method, the abilities of various turbulence models to simulate the effects of curvature without the complicating factor of streamwise pressure gradient are evaluated. The one-equation Spalart–Allmaras (SA) turbulence model overpredicts eddy viscosity, and its boundary layer profiles are too full. A curvature-corrected version of this model improves results, which are sensitive to the choice of a particular constant. An explicit algebraic stress model does a reasonable job predicting this flow field. However, results can be slightly improved by modifying the assumption on anisotropy equilibrium in the model's derivation. The resulting curvature-corrected explicit algebraic stress model (EASM) possesses no heuristic functions or additional constants. It slightly lowers the computed skin friction coefficient and the turbulent stress levels for this case, in better agreement with experiment. The effect on computed velocity profiles is minimal. 相似文献
770.
This paper is an overview of our research program in intelligent systems. Our object of study is constructed complex systems, which are software and hardware systems mediated or managed by computers. We describe how biological systems provide stiff competition for constructed complex systems in the areas of autonomy and intelligence, robustness, adaptability, and communication. We describe our computationally reflective integration infrastructure, called ‘wrappings', and show how it can provide many of the necessary flexibilities. We also describe two directions of research in computational semiotics, which for us means the study of the use of symbols by computing systems. We describe our ‘conceptual categories', which are a method of knowledge representation that supports these flexibilities, and some new results on symbol systems, which leads to some new mathematical questions about what can be represented in formal systems and how they can be extended automatically. These are then combined to describe our architecture, which we are currently in the process of implementing. 相似文献