5,602 research outputs found
Link between K-absorption edges and thermodynamic properties of warm-dense plasmas established by improved first-principles method
A precise calculation that translates shifts of X-ray K-absorption edges to
variations of thermodynamic properties allows quantitative characterization of
interior thermodynamic properties of warm dense plasmas by X-ray absorption
techniques, which provides essential information for inertial confinement
fusion and other astrophysical applications. We show that this interpretation
can be achieved through an improved first-principles method. Our calculation
shows that the shift of K-edges exhibits selective sensitivity to thermal
parameters and thus would be a suitable temperature index to warm dense
plasmas. We also show with a simple model that the shift of K-edges can be used
to detect inhomogeneity inside warm dense plasmas when combined with other
experimental tools
Extended First-Principles Molecular Dynamics Method From Cold Materials to Hot Dense Plasmas
An extended first-principles molecular dynamics (FPMD) method based on
Kohn-Sham scheme is proposed to elevate the temperature limit of the FPMD
method in the calculation of dense plasmas. The extended method treats the wave
functions of high energy electrons as plane waves analytically, and thus
expands the application of the FPMD method to the region of hot dense plasmas
without suffering from the formidable computational costs. In addition, the
extended method inherits the high accuracy of the Kohn-Sham scheme and keeps
the information of elec- tronic structures. This gives an edge to the extended
method in the calculation of the lowering of ionization potential, X-ray
absorption/emission spectra, opacity, and high-Z dense plasmas, which are of
particular interest to astrophysics, inertial confinement fusion engineering,
and laboratory astrophysics
First-Principles Calculation of Principal Hugoniot and K-Shell X-ray Absorption Spectra for Warm Dense KCl
Principal Hugoniot and K-shell X-ray absorption spectra of warm dense KCl are
calculated using the first-principles molecular dynamics method. Evolution of
electronic structures as well as the influence of the approximate description
of ionization on pressure (caused by the underestimation of the energy gap
between conduction bands and valence bands) in the first-principles method are
illustrated by the calculation. Pressure ionization and thermal smearing are
shown as the major factors to prevent the deviation of pressure from global
accumulation along the Hugoniot. In addition, cancellation between electronic
kinetic pressure and virial pressure further reduces the deviation. The
calculation of X-ray absorption spectra shows that the band gap of KCl persists
after the pressure ionization of the electrons of Cl and K taking place at
lower energy, which provides a detailed understanding to the evolution of
electronic structures of warm dense matter
PHRIT: Parametric Hand Representation with Implicit Template
We propose PHRIT, a novel approach for parametric hand mesh modeling with an
implicit template that combines the advantages of both parametric meshes and
implicit representations. Our method represents deformable hand shapes using
signed distance fields (SDFs) with part-based shape priors, utilizing a
deformation field to execute the deformation. The model offers efficient
high-fidelity hand reconstruction by deforming the canonical template at
infinite resolution. Additionally, it is fully differentiable and can be easily
used in hand modeling since it can be driven by the skeleton and shape latent
codes. We evaluate PHRIT on multiple downstream tasks, including
skeleton-driven hand reconstruction, shapes from point clouds, and single-view
3D reconstruction, demonstrating that our approach achieves realistic and
immersive hand modeling with state-of-the-art performance.Comment: Accepted by ICCV202
Discovery From Non-Parties (Third-Party Discovery) in International Arbitration
International arbitration rules and many arbitration laws usually provide procedures that permit tribunals to order parties to disclose documents and other materials to the other parties.1 More complex are the rules that determine opportunities to obtain discovery from persons that are not party to the arbitration (third-party discovery). This article will review third-party discovery under the Federal Arbitration Act (FAA) and the provisions of the US Code s.1782 that authorise US courts to act in aid of actions before foreign tribunals. Section 1782 has unique interest at this time because it figured prominently in the EU antitrust investigation of Intel that was initiated on request from Advanced Micro Devices (AMD). Early in that investigation, AMD filed a s.1782 request in the US District Court to obtain evidence from US sources for submission to the DG-Competition of the European Commission (EC). This request ultimately led to the Supreme Court’s decision in Intel Corp v Advanced Micro Devices Inc2 which appeared to significantly expand the scope of s.1782. Ironically, after AMD won on key legal issues in the Supreme Court, the District Court on remand exercised its discretion and denied the request for judicial assistance. This paper first describes the FAA non-party discovery rules and the split among the federal appellate courts concerning the authority of arbitrators to order prehearing discovery from non-parties. Next, it provides an analysis of the meaning of the terms “interested party” and “tribunal”—terms that were controversially interpreted by the Supreme Court in Intel and are essential to the application of s.1782. Finally, it discusses the “discretionary” factors used by the federal courts in deciding whether to grant a s.1782 request even when the statutory criteria are met. The opportunity to exercise this discretion seems to rebut the argument that the Supreme Court’s interpretation of s.1782 gives participants before foreign tribunals more discovery rights in the United States than are available to the parties in arbitrations covered by the FAA
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