Oecologia 110, 449 (1997)]. The analysis and ecological interpretation of this issue are complex, but low levels of cover in the unmanipulated reference plots at some of our sites (sometimes 50% at the annual-dominated Portuguese field site) provide evidence against the automatic exclusion of plots with low cover.

Polarized Raman spectra were obtained from a rope of aligned semiconducting single-wall nanotubes (SWNTs) in the vicinity of the D band and the G band. Based on group theory analysis and related theoretical predictions, the G-band profile was deconvolved into four intrinsic SWNT components with the following symmetry assignments: 1549 cm(-1) [E2(E(2g))], 1567 cm(-1) [A(A(1g))+E1(E(1g))], 1590 cm(-1) [A(A(1g))+E1(E(1g))] and 1607 cm(-1) [E2(E(2g))]. The frequency shifts of the tangential G modes from the 2D graphitelike E(2g(2)) frequency are discussed in terms of the nanotube geometry.

No abstract

A new synthetic strategy (Al-compensation method) for LNCA cathodes is proposed in this paper. As a result, the obtained LNCA electrodes exhibit a more stable layered structure and enhanced electrochemical performances.

Hydrogen Storage in Single-Walled Carbon Nanotubes at Room Temperature.-Single-walled carbon nanotubes with a large mean diameter of about 1.85 nm are prepared by a semicontineous hydrogen arc discharge method. These nanotubes achieve a H 2 storage capacity of 4.2 wt% (or a H:C atomic ratio of 0.52) at room temperature under modestly high pressure (about 10 MPa). -(LIU, C.; FAN, Y. Y.; LIU, M.; CONG, H. T.; CHENG, H. M.; DRESSELHAUS, M. S.; Science (Washington, D.