168,556 research outputs found
Effects of Isotope Substitution on Local Heating and Inelastic current in Hydrogen Molecular Junctions
Using first principle approaches, we investigate the effects of isotope
substitution on the inelastic features in the hydrogen molecular junction. We
observe thatlocal heating and inelastic current have significant
isotope-substitution effects. Due to the contact characters, the energies of
excited molecular vibrationsare inverse proportional to the square root of the
mass. The heavier the molecule, the smaller the onset bias. In the and
junctions, the heavier molecule has a smaller magnitude of
electron-vibration interaction. Consequently, there is a crossing in the local
temperature around . In the HD junction, the electron-vibration
interaction is enhanced by asymmetric distribution in mass. It leads to the
largest discontinuity in the differential conductance and the most prominent
heating in the HD junction. We predict that the junction instability is
relevant to isotope substitution. The HD junction has the smallest breakdown
voltage compared with the and junction
Nucleon partonic spin structure to be explored by the unpolarized Drell-Yan program of COMPASS experiment at CERN
The observation of the violation of Lam-Tung relation in the
Drell-Yan process triggered many theoretical speculations. The TMD Boer-Mulders
functions characterizing the correlation of transverse momentum and transverse
spin for partons in unpolarized hadrons could nicely account for the violation.
The COMPASS experiment at CERN will measure the angular distributions of
dimuons from the unpolarized Drell-Yan process over a wide kinematic region and
study the beam particle dependence. Significant statistics is expected from a
successful run in 2015 which will bring further understanding of the origin of
the violation of Lam-Tung relation and of the partonic transverse spin
structure of the nucleon.Comment: Proceedings of the 21st International Symposium on Spin Physics -
October 20-24, 2014, Beijing, China; 6 pages, 3 figures, 1 tabl
High dimensional generalized empirical likelihood for moment restrictions with dependent data
This paper considers the maximum generalized empirical likelihood (GEL)
estimation and inference on parameters identified by high dimensional moment
restrictions with weakly dependent data when the dimensions of the moment
restrictions and the parameters diverge along with the sample size. The
consistency with rates and the asymptotic normality of the GEL estimator are
obtained by properly restricting the growth rates of the dimensions of the
parameters and the moment restrictions, as well as the degree of data
dependence. It is shown that even in the high dimensional time series setting,
the GEL ratio can still behave like a chi-square random variable
asymptotically. A consistent test for the over-identification is proposed. A
penalized GEL method is also provided for estimation under sparsity setting
The relationships between corruption and pollution on corruption regimes
Previous studies have focused mainly on the effect of corruption on pollution. The results of these studies show an inverted U-shaped relationship between economic growth and pollution. In addition, some researchers have suggested that corruption plays an important role in determining pollution. This study proposes the hypothesis of a nonlinear long-run relationship between pollution and corruption. The goal of the study is to investigate the threshold cointegration effect of pollution on corruption using panel data for 62 countries over the period from 1997 to 2004. The results show that the effect of the Corruption Perceptions Index (CPI) on pollution is insignificant in low-corruption regimes. This implies that corruption does not slow down environmental pollution in countries with low corruption. The impact of the CPI on environmental pollution is also insignificant in high-corruption regimes. This result implies that corruption has no adverse impact on environmental pollution in countries with high corruption.Corruption, Pollution, Threshold, Error-Correction Model
The effect of global-scale divergent circulation on the atmospheric water vapor transport and maintenance
The detection, distribution, and dynamics of atmospheric water on Earth was examined. How the high levels of water vapor and precipitation that occur over the tropics during the monsoon season result from the development of a strong divergent atmospheric circulation is discussed
Anisotropic quaternion Carnot groups: geometric analysis and Green's function
We construct examples of 2-step Carnot groups related to quaternions and
study their fine structure and geometric properties. This involves the
Hamiltonian formalism, which is used to obtain explicit equations for geodesics
and the computation of the number of geodesics joining two different points on
these groups. We able to find the explicit lengths of geodesics. We present the
fundamental solutions of the Heat and sub-Laplace equations for these
anisotropic groups and obtain some estimates for them, which may be useful.Comment: 39 pages, 5 figure
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