2,984 research outputs found
Recent CMS Results on Forward and Small-x QCD Physics
Recent CMS results on Forward and Small-x QCD Physics are presented. Those
include the measurement of the Underlying Event activity and the study of jet
production at large rapidity separation.Comment: 4 pages, 2 figures, proceedings of Physics at LHC 2012, 4-9 June
2012, UBC, Vancouver, B
Log-Sobolev inequality for the and measures
The continuum and measures are shown to satisfy a
log-Sobolev inequality uniformly in the lattice regularisation under the
optimal assumption that their susceptibility is bounded. In particular, this
applies to all coupling constants in any finite volume, and uniformly in the
volume in the entire high temperature phases of the and
models.
The proof uses a general criterion for the log-Sobolev inequality in terms of
the Polchinski (renormalisation group) equation, a recently proved remarkable
correlation inequality for Ising models with general external fields, the
Perron--Frobenius theorem, and bounds on the susceptibilities of the
and measures obtained using skeleton inequalities.Comment: Minor revisions, accepte
Opposing Mechanisms Support the Voluntary Forgetting of Unwanted Memories
SummaryReminders of the past can trigger the recollection of events that one would rather forget. Here, using fMRI, we demonstrate two distinct neural mechanisms that foster the intentional forgetting of such unwanted memories. Both mechanisms impair long-term retention by limiting momentary awareness of the memories, yet they operate in opposite ways. One mechanism, direct suppression, disengages episodic retrieval through the systemic inhibition of hippocampal processing that originates from right dorsolateral prefrontal cortex (PFC). The opposite mechanism, thought substitution, instead engages retrieval processes to occupy the limited focus of awareness with a substitute memory. It is mediated by interactions between left caudal and midventrolateral PFC that support the selective retrieval of substitutes in the context of prepotent, unwanted memories. These findings suggest that we are not at the mercy of passive forgetting; rather, our memories can be shaped by two opposite mechanisms of mnemonic control
Ductile to brittle transition of an A508 steel characterized by Charpy impact test, part I., experimental results
International audienceThis study is devoted to the ductileâbrittle transition behavior of a French A508 Cl3 (16MND5) steel. Due to its importance for the safety assessment of PWR vessels, a full characterization of this steel with Charpy V-notch test in this range of temperature was undertaken. The aim of this study is to provide a wide experimental database and microstructural observations to supply, calibrate and validate models used in a local approach methodology. Mechanical and fracture properties of the steel have been investigated over a wide range of temperatures and strain-rates. Effects of impact velocity on ductileâbrittle transition curve, on ductile tearing and on notch temperature rise are presented and discussed. A detailed study of ductile crack initiation and growth in Charpy specimens is also carried out. From fractographic investigations of the microvoids nucleation around carbide second phase particles, a plastic strain threshold for nucleation is determined for this material. A508 Cl3 steels undergo a transition in fracture toughness properties with temperature, due to a change in fracture mode from microvoids coalescence to cleavage fracture. A systematic investigation on the nature and the position of cleavage triggering sites and on any change in the ductile to brittle transition (DBT) range has been carried out. This leads to the conclusion that manganese sulfide inclusions do not play an increasing role with increasing test temperature as recently mentioned in other studies on A508 Cl3 steel with a higher sulfur content. In a companion paper [Tanguy et al., Engng. Fract. Mech., in press], the numerical simulation of the Charpy test in the ductileâbrittle transition range using fully coupled local approach to fracture is presented
Bottom-up model of adsorption and transport in multiscale porous media
We develop a model of transport in multiscale porous media which accounts for adsorption in the different porosity scales. This model employs statistical mechanics to upscale molecular simulation and describe adsorption and transport at larger time and length scales. Using atom-scale simulations, which capture the changes in adsorption and transport with temperature, pressure, pore size, etc., this approach does not assume any adsorption or flow type. Moreover, by relating the local chemical potential ÎŒ(r) and density Ï(r), the present model accounts for adsorption effects and possible changes in the confined fluid state upon transport. This model constitutes a bottom-up framework of adsorption and transport in multiscale materials as it (1) describes the adsorption-transport interplay, (2) accounts for the hydrodynamics breakdown at the nm scale, and (3) is multiscale.France. Investissements d'avenir (ICoME2/ANR-11-LABX-0053)France. Investissements d'avenir (A*NUDEX/ANR-11-IDEX-0001-02)Schlumberger FoundationShell Oil Compan
- âŠ