Disposable, stable media for reproducible surface-enhanced Raman spectroscopy

Large numbers of identical and stable SE(R)RS [surface-enhanced (resonance) Raman]-active media, which are convenient to handle and manipulate but sufficiently inexpensive that they can be used once and then discarded, have been prepared by isolating nanoparticles from Ag and Au sols in hydrophilic polymer gels. The preparation simply involves mixing a suitable polymer with the sol to give a viscous suspension that can be coated onto a substrate and dried to form a hard translucent film. The films remain inactive until they are treated with aqueous analyte solution, which causes the film to swell and brings the analyte into contact with the active metal particles. The swollen films give strong SERS spectra which are effectively identical to those obtained from simple sols. The advantage of this method is that the dried polymers can be stored indefinitely before use and that they give a high degree of spectral reproducibility.

Stable GeV Ion Beam Acceleration from Thin Foils by Circularly Polarized Laser Pulses

A stable relativistic ion acceleration regime for thin foils irradiated by circularly polarized laser pulses is suggested. In this regime, the "light-sail" stage of radiation pressure acceleration for ions is smoothly connected with the initial relativistic "hole-boring" stage, and a defined relationship between laser intensity I(0), foil density n(0), and thickness l(0) should be satisfied. For foils with a wide range of n(0), the required I(0) and l(0) for the regime are theoretically estimated and verified with the particle-in-cell code ILLUMINATION. It is shown for the first time by 2D simulations that high-density monoenergetic ion beams with energy above GeV/u and divergence of 10 degrees are produced by circularly polarized lasers at intensities of 10(22) W/cm(2), which are within reach of current laser systems.

Stable isomorphism of dual operator spaces

We prove that two dual operator spaces $X$ and $Y$ are stably isomorphic if and only if there exist completely isometric normal representations $phi$ and $psi$ of $X$ and $Y$, respectively, and ternary rings of operators $M_1, M_2$ such that $phi (X)= [M_2^*psi (Y)M_1]^{-w^*}$ and $psi (Y)=[M_2phi (X)M_1^*].$ We prove that this is equivalent to certain canonical dual operator algebras associated with the operator spaces being stably isomorphic. We apply these operator space results to prove that certain dual operator algebras are stably isomorphic if and only if they are isomorphic. We provide examples motivated by CSL algebra theory.

Stable isotope analysis of archived roach (Rutilus rutilus) scales for retrospective study of shallow lake responses to nutrient reduction

1. There is increasing interest in the use of stable isotope analysis of archived materials to study the long-term impacts of lake perturbations, including nutrient manipulation or species invasion. We tested the utility of this approach in a shallow productive lake using the zooplanktivorous early life stages of roach ( Rutilus rutilus), a fish species that is widespread throughout Eurasian lakes.