8,267 research outputs found
NLO Productions of and with a Global Extraction of the Jet Transport Parameter in Heavy Ion collisions
In this work, we pave the way to calculate the productions of and
mesons at large in p+p and A+A collisions at the RHIC and
the LHC. The meson fragmentation functions (FFs) in vacuum at
next-to-leading order (NLO) are obtained by evolving NLO DGLAP evolution
equations with rescaled FFs at initial scale GeV from
a broken SU(3) model, and the FFs in vacuum are taken from AKK08
parametrization directly. Within the framework of the NLO pQCD improved parton
model, we make good descriptions of the experimental data on and
in p+p both at the RHIC and the LHC. With the higher-twist
approach to take into account the jet quenching effect by medium modified FFs,
the nuclear modification factors for meson and meson at
the RHIC and the LHC are presented with different sets of jet transport
coefficient . Then we make a global extraction of at the
RHIC and the LHC by confronting our model calculations with all available data
on 6 identified mesons: , , , , , and
. The minimum value of the total for productions of
these mesons gives the best value of for Au+Au
collisions with GeV at the RHIC, and for Pb+Pb collisions with TeV at the LHC
respectively, with the QGP spacetime evolution given by an event-by-event
viscous hydrodynamics model IEBE-VISHNU. With these global extracted values of
, the nuclear modification factors of , , ,
, , and in A+A collisions are presented, and
predictions of yield ratios such as and at
large in heavy-ion collisions at the RHIC and the LHC are provided.Comment: 9 pages, 13 figures, 1 tabl
On Some New Nonlinear Delay Integral Inequalities
AbstractSome new nonlinear delay integral inequalities of Ou-Iang type are obtained which generalise some results of B. G. Pachpatte (1995, Period. Math. Hungar.31, 229–234) and E. H. Yang (1997, Ann. Differential Equations13, 180–188). An application example is also indicated
Research of quasi-solid fracture behavior of casting AI-4.5Cu alloys
The influencing mechanisms of elements Ti and Ce and their interactions on fracture behaviors of casting alloys AI-4.5Cu-0.6Mn were studied by observing tensile fracture behavior in quasi-solid zone under SEM and EDX instruments.The results indicate that the resistance stress against hot cracking can be improved obviously by addition of Ti, because of its grain refining function. It is also found that, when Ce is added into the alloys, besides its effect in refining crystalline, the mechanical behavior of lower melting point eutectic phase in quasi-solid zone can be improved efficiently by some compounds with Ce formed and deposited between dendrites. Therefore, a colligating effect of Ti and Ce on improving resistance stress against hot cracking is more efficient than that only single alloy element is applied. When hot cracking occurs, grains yield at first, and then crack spreads. Both inter-grain and trans-grain fractures are observed, but the major fracture manner is brittleness
Device-scale atomistic modelling of phase-change memory materials
Computer simulations can play a central role in the understanding of phase-change materials and the development of advanced memory technologies. However, direct quantum-mechanical simulations are limited to simplified models containing a few hundred or thousand atoms. Here we report a machine-learning-based potential model that is trained using quantum-mechanical data and can be used to simulate a range of germanium–antimony–tellurium compositions—typical phase-change materials—under realistic device conditions. The speed of our model enables atomistic simulations of multiple thermal cycles and delicate operations for neuro-inspired computing, specifically cumulative SET and iterative RESET. A device-scale (40 × 20 × 20 nm3) model containing over half a million atoms shows that our machine-learning approach can directly describe technologically relevant processes in memory devices based on phase-change materials
Foot ulcers associated with external trauma among people with diabetes: An integrative review of the origin of trauma and outcomes
Background Foot ulcers are common among people with diabetes. These ulcers are caused by a number of factors including trauma. To date, research findings on the origin of external trauma and the outcome of foot ulcers resulting from an external trauma have not been summarised. Objective To examine the origin of external trauma that contribute to the development of foot ulcers among people with diabetes and the outcome of such ulcers. Design An integrative review. Settings Hospital/community. Participants Patients with diabetes and foot ulcer. Method The Joanna Briggs framework was used to underpin this integrative review. Six different databases (CINAHL +, Medline, SCOPUS, Embase, ProQuest and Web of Science databases) were searched systematically to find research publications reporting traumas that contributed to foot ulcers sustained by people with diabetes. The search was limited to articles published in English. The search revealed 3193 articles that were filtered to 78 articles to be assessed at the full-text level and 45 articles were subsequently included. Quality appraisal was conducted independently by two reviewers, using the Joanna Briggs Institute (JBI) Critical Appraisal tools. Data were extracted into a form developed for the purpose of this review. Narrative synthesis was used to manage the extracted verbatim details on the origin of external trauma contributing to foot ulcers and the outcomes. Results The origins of external trauma were summarised into two domains and further specified into 16 categories. The identified traumas were mainly minor and originated within the home environment. The most commonly reported origins of external trauma were puncture wounds, ill-fitting shoes and self-care practices that caused foot ulcers. Twenty-seven studies reported outcomes following the development of an ulcer. Twenty-two studies reported amputation as an outcome and mortality was reported in 10 studies. It was not clear whether these outcomes were directly related to the foot ulcer or related to other diabetes-related complications. Conclusions The majority of ulcers occurred in the home environment and were preventable in nature. The assessment of an individual\u27s local context, particularly the home and actions to reduce risk is a priority. The extent of the risks related to external trauma need to be more widely communicated through clinical guidelines and training opportunities for frontline staff. Tweetable abstract The main origins of external foot trauma among people with diabetes were puncture wounds, ill-fitting footwear and self-care practices
catena-Poly[[diaquabis(formato-κO)cobalt(II)]-μ2-2,6-bis(pyridin-4-yl)-4,4′-bipyridine-κ2 N 2:N 6]
In the title complex, [Co(CHO2)2(C20H14N4)(H2O)2]n, the CoII ion, lying on an inversion center, is six-coordinated by two O atoms from two monodentate formate ligands, two N atoms from two 2,6-bis(pyridin-4-yl)-4,4′-bipyridine (4-pybpy) ligands and two water molecules, displaying an octahedral geometry. The 4-pybpy ligand, having a twofold rotation axis, functions in a bridging coordination mode, connecting the CoII ions into a corrugated chain along [01]. The chains are further linked into a three-dimensional supramolecular network by O—H⋯O, C—H⋯N and C—H⋯O hydrogen bonds and π–π stacking interactions between the pyridine rings [centroid-to-centroid distance = 3.743 (2) Å]
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