Based on recent theoretical photoluminescence intensity calculations, the population densities of sixteen semiconducting single-walled carbon nanotubes grown by alcohol catalytic chemical vapor deposition were estimated for two different temperatures. The profiles of population density merely as functions of tube-diameter or chiral angle are found to be widely scattered. However, systematic profiles are detectable when separately split into (2n + m), (n + 2m) and (n - m) family arrays. Apart from these well-knit family behaviors, the population densities of the group of nanotubes forming another three possible series [viz. constant-n, constant-m and constant-(n + m)] also show evidence of good correlations. Hence, a two-dimensional chiral-zone selective growth principle is hypothesized.

The effect of surface modification on the tensile strength of the bonded interface of Al alloy and SUS304 stainless steel was investigated by SEM observations of interfacial microstructures and fractured surfaces. Aluminum surfaces were modified by boiling in 5% aqueous solution of NaOH for 20 s and 99.7% Acetic acid for 60 s. Bonding was performed at bonding temperature of 753 ~ 813 K under a pressure of 6 MPa (bonding time of 1.8 ks). As a result of surface modification, bonded joints were obtained at a bonding temperature 20 K lower than that required for non-modified surfaces, and the bonded strength was comparable to that of the maximum load.

No abstract

No abstract

No abstract