相关论文: Migration of helium-pair in metals
Point defects such as interstitial atoms are known to be attracted to screw dislocations. Understanding these interaction mechanisms is key to predicting the plasticity of real materials. Using a new machine learning interatomic potential…
A free-parameter linear-combination-of-atomic-orbitals approach is presented for analyzing the stopping power of slow ions moving in a metal. The method is applied to the case of He moving in alkali metals. Mean stopping powers for He…
Most elemental metals under ambient conditions adopt simple structures such as BCC, FCC and HCP in specific groupings across the Periodic Table, and on compression, many of these elements undergo transitions to surprisingly complex…
We have calculated the ground state electronic structure of He under pressure from 0 to 1500 GPa using both all-electron full-potential and pseudopotential methods based on the density functional theory (DFT). We find that throughout this…
We report studies of solid helium contained inside a torsional oscillator, at temperatures between 1.07K and 1.87K. We grew single crystals inside the oscillator using commercially pure $^4$He and $^3$He-$^4$He mixtures containing 100 ppm…
With the first principles calculations of H and He induced energetics change we demonstrate that in W the accumulation of H (up to 9) and He (up to 4) in a single vacancy (V) surprisingly reduce the formation energy of first and second…
The recent discovery of examples of intermediate-mass helium stars have offered new insights into interacting binaries. These observations will allow significant improvements in our understanding of helium stars. However, in the creation of…
Two leading hypotheses for hot Jupiter migration are disk migration and high-eccentricity migration (HEM). Stellar obliquity is commonly used to distinguish them, as high obliquity often accompanies HEM. However, low obliquity does not…
We report how the electron transport through a solid-state metal/Gly-Gly-His tripeptide (GGH) monolayer/metal junction and the metal/GGH work function are modified by the GGH complexation with Cu2+ ions. Conducting AFM is used to measure…
UO2 and (U,Pu)O2 solid solutions (the so-called MOX) nowadays are used as commercial nuclear fuels in many countries. One of the safety issues during the storage of these fuels is related to their self-irradiation that produces and…
The extremely low solubility of helium in liquid metals may lead to rapid supersaturation, promoting spontaneous formation of helium bubbles by nucleation. Once nucleated, the stability of these bubbles is governed by the properties of the…
Crystal grains of solid $^4$He can move in relation to each other even when embedded inside the solid. In this work, we characterize a macroscopic motion of solid hcp $^4$He composed of such grains. Motion is induced by applying an external…
We report the results of a comprehensive reanalysis of Ulysses observations of interstellar He atoms flowing through the solar system, the goal being to reassess the interstellar He flow vector and to search for evidence of variability in…
The interaction of edge dislocation with helium-implantation-induced defects in tungsten is investigated using molecular dynamics. Following prior investigations, we consider defects with two helium ions in a vacancy with a…
The motion of helium crystals has been experimentally studied when the crystals fall in the superfluid liquid owing to gravity at temperatures above the roughening transitions where the whole crystal surface is in the atomically rough…
Measurements of the difference between the squared charge radii of the helion ($^3$He nucleus) and the $\alpha$-particle ($^4$He nucleus) have been characterized by longstanding tensions, recently spotlighted in the 3.6 $\sigma$ discrepancy…
By use of a novel experimental design, one that provides for superfluid helium in contact with bulk hcp 4He off the melting curve, we have observed the DC transport of mass through a cell filled with solid 4He in the hcp region of the phase…
Potential Energy Surface for the ($\mathrm{\bar{p}} - \mathrm{He}^{2+} - \mathrm{He}$) system is calculated in the framework of the restricted (singlet spin state) Hartree-Fock method with subsequent account of the electronic correlations…
Molecular clouds typically consist of 3/4 H2, 1/4 He and traces of heavier elements. In an earlier work we showed that at very low temperatures and high densities, H2 can be in a phase transition leading to the formation of ice clumps as…
HERA $ep$ collider provides unique information on the proton structure. High center of mass energy $s=320$ GeV gives access to both the low Bjorken-$x$ domain and regime of high momentum transfers $Q$. Recently the H1 collaboration reported…