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941.
M. J. Gilbert F. Awaja G. L. Kelly B. L. Fox R. Brynolf P. J. Pigram 《Surface and interface analysis : SIA》2011,43(5):856-864
The main challenges in the manufacture of composite materials are low surface energy and the presence of silicon‐containing contaminants, both of which greatly reduce surface adhesive strength. In this study, carbon fiber (CF) and E‐glass epoxy resin composites were surface treated with the Accelerated Thermo‐molecular adhesion Process (ATmaP). ATmaP is a multiaction surface treatment process where tailored nitrogen and oxygen functionalities are generated on the surface of the sample through the vaporization and atomization of n‐methylpyrrolidone solution, injected via specially designed flame‐treatment equipment. The treated surfaces of the polymer composites were analyzed using XPS, time of flight secondary ion mass spectrometry (ToF‐SIMS), contact angle (CA) analysis and direct adhesion measurements. ATmaP treatment increased the surface concentration of polar functional groups while reducing surface contamination, resulting in increased adhesion strength. XPS and ToF‐SIMS showed a significant decrease in silicon‐containing species on the surface after ATmaP treatment. E‐glass composite showed higher adhesion strength than CF composite, correlating with higher surface energy, higher concentrations of nitrogen and C?O functional groups (from XPS) and higher concentrations of oxygen and nitrogen‐containing functional groups (particularly C2H3O+ and C2H5NO+ molecular ions, from ToF‐SIMS). Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
942.
We study the following question: How few edges can we delete from any -free graph on vertices to make the resulting graph -colorable? It turns out that various classical problems in extremal graph theory are special cases of this question. For any fixed odd cycle, we determine the answer up to a constant factor when is sufficiently large. We also prove an upper bound when is a fixed clique that we conjecture is tight up to a constant factor, and prove upper bounds for more general families of graphs. We apply our results to get a new bound on the maximum cut of graphs with a forbidden odd cycle in terms of the number of edges. 相似文献