相关论文: Structural Organization of Space Polymers
Several lines of evidence indicate a non-chondritic composition for Bulk Earth. If Earth formed from the accretion of chondritic material, its non-chondritic composition, in particular the super-chondritic 142Nd/144Nd and low Mg/Fe ratios,…
The bulk density of a planet, as measured by mass and radius, is a result of planet structure and composition. Relative proportions of iron core, rocky mantle, and gaseous envelopes are degenerate for a given density. This degeneracy is…
We aim to better understand how the spatial structure of molecular clouds is governed by turbulence. For that, we study the large-scale spatial distribution of low density molecular gas and search for characteristic length scales. We employ…
The empty, extensive low-density lattice topology of hemoglycin is examined to understand how in space, and possibly as early as 800M years into cosmic time a rod-like polymer of glycine and iron came into dominance. A central question to…
Globular Clusters (GCs) are natural laboratories where stellar and chemical evolution can be studied in detail. In addition, their chemical patterns and kinematics can tell us wich Galactic structure (Disk, Bulge, Halo or extragalactic) the…
Several fcc- and hcp-structured Ir-Os alloys have been recently studied up to 30 GPa at room temperature by means of synchrotron-based X-ray powder diffraction in diamond anvil cells. Using their bulk moduli -which increase with increasing…
Molecular line surveys are among the main tools to probe the structure and physical conditions in protoplanetary disks (PPDs), the birthplace of planets. The large radial and vertical temperature as well as density gradients in these PPDs…
The composition and internal structure of gas giant exoplanets encode key information about their formation and evolution. We investigate how different assumed interior structures affect the inferred bulk metallicity and its correlation…
In the framework of the relativistic mean field model with Thomas-Fermi approximation, we study the structures of low density nuclear matter in a three-dimensional geometry with reflection symmetry. The numerical accuracy and efficiency are…
The chemical composition of a planetary body reflects its starting conditions modified by numerous processes during its formation and geological evolution. Measurements by X-ray, gamma-ray, and neutron spectrometers on the MESSENGER…
White dwarf planetary systems uniquely link the bulk elemental composition of exoplanetary material to the mineralogy as photospheric abundances can be compared to circumstellar dust mineralogy. This study re-examines Spitzer/IRS spectra of…
In the framework of algebraic topology the closed sequence of 4-dimensional polyhedra (algebraic polytopes) was defined. This sequence is started by the polytope {240}, discovered by Coxeter, and is determined by the second coordination…
We present observations of the intermediate to massive star-forming region I05345+3157 using the molecular line tracer CS(2-1) with CARMA to reveal the properties of the dense gas cores. Seven gas cores are identified in the integrated…
Intermediate mass protostars, the bridge between the very common solar-like protostars and the more massive, but rarer, O and B stars, can only be studied at high physical spatial resolutions in a handful of clouds. In this paper we present…
The electronic structure of (group-III) metal-monochalcogenide monolayers exhibits many unusual features. Some, such as the unusually distorted upper valence band dispersion we describe as a 'caldera', are primarily the result of purely…
We present a structural analysis of NGC891, an edge-on galaxy that has long been considered to be an analogue of the Milky Way. Using starcounts derived from deep HST/ACS images, we detect the presence of a thick disk component in this…
A novel crystalline structure of hybrid monolayer hexagonal boron nitride (BN) and graphene is predicted by means of the first-principles calculations. This material can be derived via boron or nitrogen atoms substituted by carbon atoms…
We investigated the stability of polymeric CO2 over a wide range of pressures, temperatures, and chemical environments. We find that the I-42d polymeric structure, consisting of a three-dimensional network of corner sharing CO4 tetrahedra,…
Jammed disordered packings of non-spherical particles show significant variation in the packing density as a function of particle shape for a given packing protocol. Rotationally symmetric elongated shapes such as ellipsoids,…
Multiple loop formation in polymer macromolecules is an important feature of the chromatin organization and DNA compactification in the nuclei. We analyze the size and shape characteristics of complex polymer structures, containing in…