11,195 research outputs found
Defining Temperatures of Granular Powders Analogously with Thermodynamics to Understand the Jamming Phenomena
For the purpose of applying laws or principles originated from thermal
systems to granular athermal systems, we may need to properly define the
critical temperature concept in granular powders. The conventional
environmental temperature in thermal systems is too weak to drive movements of
particles in granular powders and cannot function as a thermal energy
indicator. For maintaining the same functionality as in thermal systems, the
temperature in granular powders is defined analogously and uniformly in this
article. The newly defined granular temperature is utilized to describe and
explain one of the most important phenomena observed in granular powders, the
jamming transition, by introducing jamming temperature and jamming volume
fraction concepts. The predictions from the equations of the jamming volume
fractions for several cases like granular powders under shear or vibration are
in line with experimental observations and empirical solutions in powder
handlings. The goal of this article is to establish similar concepts in
granular powders, allowing granular powders to be described with common laws or
principles we are familiar with in thermal systems. Our intention is to build a
bridge between thermal systems and granular powders to account for many
similarities already found between these two systems.Comment: 34 pages,15 figure
Structured illumination microscopy with unknown patterns and a statistical prior
Structured illumination microscopy (SIM) improves resolution by
down-modulating high-frequency information of an object to fit within the
passband of the optical system. Generally, the reconstruction process requires
prior knowledge of the illumination patterns, which implies a well-calibrated
and aberration-free system. Here, we propose a new \textit{algorithmic
self-calibration} strategy for SIM that does not need to know the exact
patterns {\it a priori}, but only their covariance. The algorithm, termed
PE-SIMS, includes a Pattern-Estimation (PE) step requiring the uniformity of
the sum of the illumination patterns and a SIM reconstruction procedure using a
Statistical prior (SIMS). Additionally, we perform a pixel reassignment process
(SIMS-PR) to enhance the reconstruction quality. We achieve 2 better
resolution than a conventional widefield microscope, while remaining
insensitive to aberration-induced pattern distortion and robust against
parameter tuning
Algebraic higher symmetry and categorical symmetry -- a holographic and entanglement view of symmetry
We introduce the notion of algebraic higher symmetry, which generalizes
higher symmetry and is beyond higher group. We show that an algebraic higher
symmetry in a bosonic system in -dimensional space is characterized and
classified by a local fusion -category. We find another way to describe
algebraic higher symmetry by restricting to symmetric sub Hilbert space where
symmetry transformations all become trivial. In this case, algebraic higher
symmetry can be fully characterized by a non-invertible gravitational anomaly
(i.e. an topological order in one higher dimension). Thus we also refer to
non-invertible gravitational anomaly as categorical symmetry to stress its
connection to symmetry. This provides a holographic and entanglement view of
symmetries. For a system with a categorical symmetry, its gapped state must
spontaneously break part (not all) of the symmetry, and the state with the full
symmetry must be gapless. Using such a holographic point of view, we obtain (1)
the gauging of the algebraic higher symmetry; (2) the classification of
anomalies for an algebraic higher symmetry; (3) the equivalence between classes
of systems, with different (potentially anomalous) algebraic higher symmetries
or different sets of low energy excitations, as long as they have the same
categorical symmetry; (4) the classification of gapped liquid phases for
bosonic/fermionic systems with a categorical symmetry, as gapped boundaries of
a topological order in one higher dimension (that corresponds to the
categorical symmetry). This classification includes symmetry protected trivial
(SPT) orders and symmetry enriched topological (SET) orders with an algebraic
higher symmetry.Comment: 61 pages, 31 figure
Performance and Reliability of Integrated Solar Thermal Electronics and Devices
The performance and reliability of solar thermal electrical device is studied. A
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