搜索结果: 106-120 共查到“理学 density”相关记录482条 . 查询时间(0.067 秒)
Abstract: We show that there are sets of integers with asymptotic density arbitrarily close to 1 in which there is no solution to the equation ab=c, with a,b,c in the set. We also consider some natura...
Threshold Improvement of Low-Density Lattice Codes via Spatial Coupling
Low-Density Lattice Codes Spatial Coupling Information Theory
2011/9/20
Abstract: Spatially-coupled low-density lattice codes (LDLC) are constructed using protographs. Using Monte Carlo density evolution using single-Gaussian messages, we observe that the threshold of the...
Constraints from the CMB temperature and other common observational data-sets on variable dark energy density models
Cosmology Dark energy Thermodynamics
2011/10/13
The thermodynamic and dynamical properties of a variable dark energy model with density scaling as rho_x \propto (1+z)^m, z being the redshift, are discussed following the outline of Jetzer et al. Thi...
The Turbulence Spectrum of Molecular Clouds in the Galactic Ring Survey: A Density-Dependent PCA Calibration
Turbulence Spectrum Molecular Clouds Galactic Ring Survey
2011/10/13
Turbulence plays a major role in the formation and evolution of molecular clouds. The problem is that turbulent velocities are convolved with the density of an observed region. To correct for this con...
The Log-Convex Density Conjecture and vertical surface area in warped products
The Log-Convex Density Conjecture vertical surface area warped products Differential Geometry
2011/9/19
Abstract: We examine the vertical component of surface area in the warped product of a Euclidean interval and a fiber manifold with product density. We determine general conditions under which vertica...
An HI column density threshold for cold gas formation in the Galaxy
column density threshold cold gas formation Galaxy
2011/9/28
We report the discovery of a threshold in the HI column density of Galactic gas clouds below which the formation of the cold phase of HI is inhibited. This threshold is at $N_{HI} = 2 \times 10^{20}$ ...
Prediction of the derivative discontinuity in density functional theory from an electrostatic description of the exchange and correlation potential
derivative discontinuity Prediction density functional theory electrostatic description correlation potential
2011/8/5
Abstract: We propose a new approach to approximate the exchange and correlation (XC) functional in density functional theory. The XC potential is considered as an electrostatic potential, generated by...
Equation of state at finite baryon density based on lattice QCD
lattice QCD baryon density Equation of state
2011/7/21
We employ the lattice QCD data on Taylor expansion coefficients to extend our previous parametrization of the equation of state to finite baryon density.
Testing the density matrix expansion against ab initio calculations of trapped neutron drops
density matrix neutron drops
2011/7/20
Microscopic input to a universal nuclear energy density functional can be provided through the density matrix expansion (DME), which has recently been revived and improved.
Three-dimensional calculation of inhomogeneous structure in low-density nuclear matter
low-density nuclear matter inhomogeneous structure
2011/7/20
In low-density nuclear matter which is relevant to the crust region of neutron stars and collapsing stage of supernovae, non-uniform structures called "nuclear pasta" are expected.
On the density of exponential functionals of Levy processes
Levy processes exponential functional subordinators self-similar Markov processes
2011/9/14
Abstract: In this paper, we study the existence of the density associated to the exponential functional of the L\'evy process $\xi$, \[ I_{\ee_q}:=\int_0^{\ee_q} e^{\xi_s} \, \mathrm{d}s, \] where $\e...
Gas density and star formation in the rarified regions of discs of normal and LSB galaxies
Gas density star formation rarified regions discs normal
2011/10/11
We calculated the radial profiles of the azimuthally averaged midplane gas volume density $\rho_g$ for 11 high surface brightness (HSB) spiral galaxies, 7 low surface brightness (LSB) galaxies and 3 S...
Magnetic Energy Storage and Current Density Distributions for Different Force-Free Models
Magnetic fi elds Corona - Active Regions Structure - Electric Cur- rents Current Sheets
2011/10/10
The change in the magnetic configuration due to the increase/decrease of electric current for different force-free models (potential, linear and nonlinear force-free fields) has never been studied in ...
Impact of the Electron Density on the Fixed-Node Errors in Quantum Monte Carlo
the Electron Density the Fixed-Node Errors Quantum Monte Carlo
2011/8/5
Abstract: We analyze the effect of increasing charge density on the Fixed Node Errors in Diffusion Monte Carlo by comparing FN-DMC calculations of the total ground state energy on a 4 electron system ...
Gravitationally Induced Density Wake of a Circularly Orbiting Object As an Interpretative Framework of Ubiquitous Spirals and Arcs
Induced Density Circularly Orbiting Interpretative Framework Ubiquitous Spirals
2011/10/9
An orbiting object in a gas rich environment creates a gravitational density wake containing information about the object and its orbit. Using linear perturbation theory, we analyze the observable pro...