8,239 research outputs found
Different critical points of chiral and deconfinement phase transitions in (2+1)-dimensional fermion-gauge interacting model
Based on the truncated Dyson-Schwinger equations for fermion and massive
boson propagators in QED, the fermion chiral condensate and the mass
singularities of the fermion propagator via the Schwinger function are
investigated. It is shown that the critical point of chiral phase transition is
apparently different from that of deconfinement phase transition and in Nambu
phase the fermion is confined only for small gauge boson mass.Comment: 5 Pages and 3 figure
Zoom data analysis in an introductory course in mechanical engineering
[EN] This investigation studies various data extracted from Zoom meetings which
are used in teaching an introductory course in mechanical engineering online.
The effect of using Chat tool is discussed by extracting and analyzing the data
in chat report. The parameters, such as number of chatting students, chatting
participation rate, as well as average numer of chats per student, can show
students activeness from different perspectives. Participcation in polling and
polling performance are also studied by extracting data from polling reports.
Non-graded polling activities are found to be effective of increase attendance
of students. The using of breakout room doesn’t show its effectiveness in online
learning of this introductory course.Tao, H.; Feng, B. (2021). Zoom data analysis in an introductory course in mechanical engineering. En 7th International Conference on Higher Education Advances (HEAd'21). Editorial Universitat Politècnica de València. 855-862. https://doi.org/10.4995/HEAd21.2021.12823OCS85586
Universal linear-temperature resistivity: possible quantum diffusion transport in strongly correlated superconductors
The strongly correlated electron fluids in high temperature cuprate
superconductors demonstrate an anomalous linear temperature () dependent
resistivity behavior, which persists to a wide temperature range without
exhibiting saturation. As cooling down, those electron fluids lose the
resistivity and condense into the superfluid. However, the origin of the
linear- resistivity behavior and its relationship to the strongly correlated
superconductivity remain a mystery. Here we report a universal relation
, which bridges the slope of the
linear--dependent resistivity () to the London penetration depth
at zero temperature among cuprate superconductor
BiSrCaCuO and heavy fermion superconductors
CeCoIn, where is vacuum permeability, is the Boltzmann
constant and is the reduced Planck constant. We extend this scaling
relation to different systems and found that it holds for other cuprate,
pnictide and heavy fermion superconductors as well, regardless of the
significant differences in the strength of electronic correlations, transport
directions, and doping levels. Our analysis suggests that the scaling relation
in strongly correlated superconductors could be described as a hydrodynamic
diffusive transport, with the diffusion coefficient () approaching the
quantum limit , where is the quasi-particle effective
mass.Comment: 8 pages, 2 figures, 1 tabl
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