A nearby supernova (SN) explosion in the past can be confirmed by the detection of radioisotopes on Earth that were produced and ejected by the SN. We have now measured a well resolved time profile of the 60Fe concentration in a deep-sea ferromanganese crust and found a highly significant increase 2.8 Myr ago. The amount of 60Fe is compatible with the deposition of ejecta from a SN at a distanc...

Dynamic recrystallization (DRX) is almost universally observed in the microstructure of adiabatic shear bands. It is usually admitted that DRX results from the large temperatures that develop in the band along with very high local strains. This paper reports the observation of dynamically recrystallized nanograins in Ti6Al4V alloy specimens that were impact loaded to only half the failure strai...

Grain boundary segregation provides a method for stabilization of nanocrystalline metals – the selection of an alloying element that will segregate to the boundaries can lower the grain boundary energy, attenuating the driving force for grain growth. The segregation strength, relative to mixing enthalpy, of a binary system determines the propensity for segregation stabilization. This relationsh...

Fatigue resistance of nanocrystalline commercial pure titanium obtained by hydrostatic extrusion was investigated. Coarse grained titanium and Ti6Al4V alloy were used as the reference materials. The fatigue limit and fatigue life examined at constant stress amplitude, were found to increase significantly compared to those of the coarse-grained counterparts. It is suggested that the observed imp...

BULLARD, ROBERT W., AND GORDON E. FUNKHOUSER. ES& mated regional blood J-low by rubidium 86 distribution during arousal from hibernahn. Am. J. Physiol. 203(2) : 266-270. I 962 .-The local organ or tissue blood flows during the process of arousal from hibernation have been estimated in the 13-lined ground squirrel by the Sapirstein method, which consists of the measurement of the regional distri...

We experimentally demonstrate emission of two quantum-mechanically correlated light pulses with a time delay that is coherently controlled via temporal storage of photonic states in an ensemble of rubidium atoms. The experiment is based on Raman scattering, which produces correlated pairs of spin-flipped atoms and photons, followed by coherent conversion of the atomic states into a different ph...

We report on the coherent quantum state transfer from a two-level atomic system to a single photon. Entanglement between a single photon (signal) and a two-component ensemble of cold rubidium atoms is used to project the quantum memory element (the atomic ensemble) onto any desired state by measuring the signal in a suitable basis. The atomic qubit is read out by stimulating directional emissio...

Rydberg spin-waves are optically excited in a quasi-one-dimensional atomic sample of Rb atoms. Pairwise spin-wave correlations are observed by a spatially selective transfer of the quantum state onto a light field and photoelectric correlation measurements of the light. The correlations are interpreted in terms of the dephasing of multiply excited spin-waves by long-range Rydberg interactions.

The asymmetric unit of the title compound, Rb(+)·C(4)H(3)N(2)O(3) (-)·C(4)H(4)N(2)O(3)·H(2)O, consists of one rubidium cation, a barbituric acid mol-ecule, a barbiturate anion and one water mol-ecule. The rubidium ion has seven close-contact inter-actions with O atoms, with Rb⋯O distances ranging from 2.8594 (16) to 3.2641 (14) Å. These seven O atoms together with an eighth O atom at 3.492 (2) ...