We have performed high-resolution photoluminescence spectroscopy on silicon crystals with different isotopic composition and investigated the effects of this composition on the indirect electronic band gap and phonon energies. From the relative energy shift of the indirect electronic band gap between two crystals of different isotopic composition, the zero-point renormalization energy of that e...

Authigenic aragonite preserves a carbon isotopic record of heterotrophic microbial influences on dissolved inorganic carbon (DIC) in microenvironments within shallow subtidal stromatolites from Highborne Cay, Bahamas. A greater amount of aragonite precipitates when and where respiration, rather than photosynthesis, influences local DIC, which is consistent with sulfate reduction promoting carbo...

Isotopic effects occuring during the evaporation of microgram quantities of chemically pure rubidium, potassium and lithium compounds are studied. The measured isotopic ratios show a time dependent variation corresponding to a RAYLEIGH distillation. The fractionation factor is equal to the square root of the ratio of the masses. The highest observed enrichments are 45% for lithium, 10% for pota...

Lie-isotopic lifting of the commutation and anticommutation relations of creation-annihilation bosonic and fermionic operators is considered. Lie-isotopic generalization of the associated supersymmetry generators and of the underlying superalgebra in considering of the Lie-isotopically lifted hamiltonian of supersymmetric quantum mechanical oscillator is defined. The generalised oscillator has ...

An isotopic fingerprinting method is presented to determine the origin of unknown nuclear material with forensic importance. Spent nuclear fuel of known origin has been considered as the 'unknown' nuclear material in order to demonstrate the method and verify its prediction capabilities. The method compares, using factor analysis, the measured U, Pu isotopic compositions of the 'unknown' materi...

The existence of methane in the martian atmosphere may be an indicator of subsurface life. Biological processes are known to fractionate the common isotopologues of methane, and hence measuring these isotopic ratios may yield constraints on the nature of the methane source. Any measurement of the isotopic ratios of atmospheric methane must consider the additional fractionation due to photochemi...

Isotopic analyses of the oxygen and the refractory elements chromium, tungsten, and titanium show that Earth and Moon have the same isotopic compositions for these elements. In contrast, Randal Paniello and Frédéric Moynier (Washington University in St. Louis) and James Day (Scripps Institution of Oceanography, La Jolla) report from highprecision analyses of the isotopes of the volatile element...

Introduction: Calcium-aluminum-rich inclusions (CAIs) from the metal-rich (CH/CB-like) carbonaceous chondrite Ish-eyevo are mineralogically pristine and show no evidence for postcrystallization alteration [1]. Many of them are composed of very refractory minerals, such as hibonite (CaAl 12 O 19), grossite (CaAl 4 O 7), aluminum-rich pyroxene, and perovskite (CaTiO 3). We will present oxygen iso...

Introduction: Grain size separate CG from the Murray CM2 carbonaceous chondrite contains mostly spinel grains of average diameter 0.5 μm [1]. Zinner et al. [2] found that approximately 1% of these spinel grains are of presolar origin as determined by their large O isotopic anomalies. These O isotopic measurements were made with the NanoSIMS on individual grains that were well separated from one...

This answers a question apparently first raised by Tietze [T, p. 83]. It was previously known that there were at most two knots with a given complement [CGLS, Corollary 3]. The notion of equivalence of knots can be strengthened by saying that K and K' are isotopic if the above homeomorphism h is isotopic to the identity, or, equivalently, orientation-preserving. The analog of Theorem I holds in...