搜索结果: 16-30 共查到“理学 Helium”相关记录62条 . 查询时间(0.115 秒)
Detailed study of dissipative quantum dynamics of K-2 attached to helium nanodroplets
K-2 helium nanodroplets
2011/9/9
We thoroughly investigate vibrational quantum dynamics of dimers attached to He droplets motivated by recent measurements with K2 [1]. For those femtosecond pump-probe experiments, crucial observed fe...
In this work we investigate small clusters of helium atoms using the hyperspherical harmonic basis. We consider systems with A = 2, 3, 4, 5, 6 atoms with an inter-particle potential which does not pre...
The application of the pseudostate-close-coupling method using a non-orthogonal Laguerre-L^2 basis for electron-helium scattering
Differential and total cross sections Elastic and excitation
2010/9/25
Differential and total cross sections for elastic and excitation from the ground state to n ≤ 2 states of atomic helium by electrons are computed for incident energies in the range from 5 to 50 eV. Th...
The extraordinary complex magnetic field of the helium-strong star HD 37776
The extraordinary complex magnetic field the helium-strong star HD 37776
2011/1/11
The early-type chemically peculiar stars often show strong magnetic fields on their surfaces. These magnetic topologies are organized on large scales and are believed to be close to an oblique dipole ...
Excited electron-bubble states in superfluid helium-4: a time-dependent density functional approach
Excited electron-bubble states time-dependent density functional approach
2010/11/19
We present a systematic study on the excited electron-bubble states in super uid 4He using a
time-dependent density functional approach. For the evolution of the 1P bubble state, two di erent functio...
Investigating metastable hcp solid helium below its melting pressure
quantum solids hcp solid helium metastability vacancy
2010/11/19
We report a first attempt to produce metastable hcp solid helium below its melting pressure. A focused sound pulse is emitted along the c-axis of a monodomain hcp helium-4 crystal starting from a stat...
Helium fine structure theory for determination of \alpha
Helium fine structure theory determination
2010/11/16
We present recent progress in the calculation of the helium fine-structure splitting of the 2^3P_J states, based on the quantum electrodynamic theory. Apart from the complete evaluation of m\alpha^7 ...
Prevalence of different double ionization pathways and traces of three-body collisions in strongly driven Helium
double ionization three-body collisions driven Helium
2010/11/16
We present a unified treatment of the prevalence of different double ionization (DI) pathways as a function of the sum of the final electron energies in strongly driven Helium. We do so as a function...
Fine structure of helium and light helium-like ions
Fine structure helium light helium-like ions
2010/11/16
Calculational results are presented for the fine-structure splitting of the 2^3P state of helium and helium-like ions with the nuclear charge Z up to 10. Theoretical predictions are in agreement with...
Vibrational relaxation and decoherence of Rb_2 attached to helium nanodroplets
Vibrational relaxation decoherence of Rb_2 helium nanodroplets
2010/11/16
The vibrational wave-packet dynamics of diatomic rubidium molecules (Rb_2) in triplet states formed on the surface of superfluid helium nanodroplets is investigated both experimentally and theoretica...
Vibronic Lineshapes of PTCDA Oligomers in Helium Nanodroplets
Vibronic Lineshapes PTCDA Oligomers Helium Nanodroplets
2010/10/21
Oligomers of the organic semiconductor PTCDA are studied by means of helium nanodroplet
isolation (HENDI) spectroscopy. In contrast to the monomer absorption spectrum, which exhibits
clearly separat...
Helium isotopes of seawater in the Philippine Sea and the western North Pacific
3He/4He ratios abyssal current Philippine Sea North Pacific seawater
2017/8/9
We measured helium isotopic ratios of 84 seawater samples from various depths collected in the western North Pacific Ocean and the western Philippine Sea. The 3He/4He ratios varied significantly from ...
Monitoring of temporal and spatial variations in fumarole helium and carbon dioxide characteristics at Poás and Turrialba volcanoes, Costa Rica (2001-2009)
helium isotopes carbon isotopes Central America Costa Rica volcano monitoring
2017/8/9
We report results of a 9-year monitoring program that took place from 2001 to 2009 of the helium and carbon isotope (3He/4He, δ13C) and relative abundances ratios (CO2/3He) of fumarole sites at Poás a...
Helium in old porcelain: The historical variation of the He isotopic composition in air
helium isotopes atmosphere porcelain anthropogenic fluxes Industrial Revolution
2017/8/9
It is still debated whether there is a variation of the atmospheric 3He/4He ratio, due to the anthropogenic release of radiogenic 4He contained in fossil fuels, in modern era. In this study, we measur...
Helium isotopic ratios in fluid inclusions from fluorite-rich Mississippi Valley-Type district of Asturias, northern Spain
fluorite noble gases helium isotopes fluid inclusions Asturias, MVT deposits
2017/8/9
Helium isotopes have been measured in fluorite and sulphides from fluorite-rich Mississippi Valley-type (MVT) deposits from Asturias, Spain, in order to assess the involvement of mantle and crust-deri...