5 research outputs found
Prospects in Analytical Atomic Spectrometry
Tendencies in five main branches of atomic spectrometry (absorption,
emission, mass, fluorescence and ionization spectrometry) are considered. The
first three techniques are the most widespread and universal, with the best
sensitivity attributed to atomic mass spectrometry. In the direct elemental
analysis of solid samples, the leading roles are now conquered by laser-induced
breakdown and laser ablation mass spectrometry, and the related techniques with
transfer of the laser ablation products into inductively-coupled plasma.
Advances in design of diode lasers and optical parametric oscillators promote
developments in fluorescence and ionization spectrometry and also in absorption
techniques where uses of optical cavities for increased effective absorption
pathlength are expected to expand. Prospects for analytical instrumentation are
seen in higher productivity, portability, miniaturization, incorporation of
advanced software, automated sample preparation and transition to the
multifunctional modular architecture. Steady progress and growth in
applications of plasma- and laser-based methods are observed. An interest
towards the absolute (standardless) analysis has revived, particularly in the
emission spectrometry.Comment: Proofread copy with an added full reference list of 279 citations. A
pdf version of the final published review may be requested from Alexander
Bol'shakov <[email protected]
Algebraic lattices of solvably saturated formations and their applications
In each group G, we select a system of subgroups τ(G) and say that τ is a subgroup functor if G∈τ(G) for every group G, and for every epimorphism φ:A→B and any H∈τ(A) and T∈τ(B), we have Hφ∈τ(B) and Tφ−1∈τ(A). We consider only subgroup functors τ such that for any group G all subgroups of τ(G) are subnormal in G. For any set of groups X, the symbol sτ(X) denotes the set of groups H such that H∈τ(G) for some group G∈X. A formation F is τ-closed if sτ(F)=F. The Frattini subgroup Φ(G) of a group G is the intersection of all maximal subgroups of G. A formation F is said to be solvably saturated if it contains each group G with G/Φ(N)∈F for some solvable normal subgroup N of G. Composition formations are precisely solvably saturated formations. It is shown that the lattice of all τ-closed totally composition formations is algebraic