863 research outputs found
Angular momentum I ground state probabilities of boson systems interacting by random interactions
In this paper we report our systematic calculations of angular momentum
ground state probabilities () of boson systems with spin in the
presence of random two-body interactions. It is found that the P(0) dominance
is usually not true for a system with an odd number of bosons, while it is
valid for an even number of bosons, which indicates that the P(0) dominance is
partly connected to the even number of identical particles. It is also noticed
that the 's of bosons with spin do not follow the 1/N (,
referring to the number of independent two-body matrix elements) relation. The
properties of the 's obtained in boson systems with spin are
discussed.Comment: 8 pages and 3 figure
-pairing Interactions of Fermions in a Single- Shell
In this talk I shall introduce our recent works on general pairing
interactions and pair truncation approximations for fermions in a single-j
shell, including the spin zero dominance, features of eigenvalues of fermion
systems in a single-j shell interacting by a pairing interaction.Comment: 10 pages and 4 figures, international symposiu
Geometry of random interactions
It is argued that spectral features of quantal systems with random
interactions can be given a geometric interpretation. This conjecture is
investigated in the context of two simple models: a system of randomly
interacting d bosons and one of randomly interacting fermions in a j=7/2 shell.
In both examples the probability for a given state to become the ground state
is shown to be related to a geometric property of a polygon or polyhedron which
is entirely determined by particle number, shell size, and symmetry character
of the states. Extensions to more general situations are discussed
Ground state spin 0 dominance of many-body systems with random interactions and related topics
In this talk we shall show our recent results in understanding the spin 0 ground state (0 g.s.) dominance of many-body systems. We propose
a simple approach to predict the spin g.s. probabilities which does not
require the diagonalization of a Hamiltonian with random interactions. Some
findings related to the 0 g.s. dominance will also be discussed.Comment: 11 pages and 4 figure
A study of randomness, correlations and collectivity in the nuclear shell model
A variable combination of realistic and random two-body interactions allows
the study of collective properties, such as the energy spectra and B(E2)
transition strengths in 44Ti, 48Cr and 24Mg. It is found that the average
energies of the yrast band states maintain the ordering for any degree of
randomness, but the B(E2) values lose their quadrupole collectivity when
randomness dominates the Hamiltonian. The high probability of the yrast band to
be ordered in the presence of pure random forces exhibits the strong
correlations between the different members of the band.Comment: 8 pages, 10 figures, 8 tables, submitted to Physical Review
Numerical case studies of vertical wall fire protection using water spray
AbstractStudies of vertical wall fire protection are evaluated with numerical method. Typical fire cases such as heated dry wall and upward flame spread have been validated. Results predicted by simulations are found to agree with experiment results. The combustion behavior and flame development of vertical polymethylmethacrylate slabs with different water flow rates are explored and discussed. Water spray is found to be capable of strengthening the fire resistance of combustible even under high heat flux radiation. Provided result and data are expected to provide reference for fire protection methods design and development of modern buildings
Flux dynamics and vortex phase diagram of the new superconductor
Magnetic critical current density and relaxation rate have been measured on
bulks from 1.6 K to at magnetic fields up to 8 Tesla. A vortex
phase diagram is depicted based on these measurement. Two phase boundaries
and characterizing different irreversible
flux motions are found. The is characterized by the
appearance of the linear resistivity and is attributed to quantum vortex
melting induced by quantum fluctuation of vortices in the rather clean system.
The second boundary reflects the irreversible flux motion in
some local regions due to either very strong pinning or the surface barrier on
the tiny grains.Comment: 4 pages, 5 figure
Generic Rotation in a Collective SD Nucleon-Pair Subspace
Low-lying collective states involving many nucleons interacting by a random
ensemble of two-body interactions (TBRE) are investigated in a collective
SD-pair subspace, with the collective pairs defined dynamically from the
two-nucleon system. It is found that in this truncated pair subspace collective
vibrations arise naturally for a general TBRE hamiltonian whereas collective
rotations do not. A hamiltonian restricted to include only a few randomly
generated separable terms is able to produce collective rotational behavior, as
long as it includes a reasonably strong quadrupole-quadrupole component.
Similar results arise in the full shell model space. These results suggest that
the structure of the hamiltonian is key to producing generic collective
rotation.Comment: 11 pages, 5 figure
To tweet or not to tweet about schizophrenia systematic reviews (TweetSz): study protocol for a randomised controlled trial
Introduction: The Cochrane Schizophrenia Group (CSzG) has produced and maintained systematic reviews of effects of interventions for schizophrenia and related illness. Each review has a Plain Language Summary (PLS), for those without specialised knowledge, and an abstract, which are freely available from The Cochrane Library (https://summaries.cochrane.org). Increasingly, evidence is being distributed using social media such as Twitter and Weibo (in China) alongside traditional publications.
Methods and analysis: In a prospective two-arm, parallel, open randomised controlled trial with a 1:1 allocation ratio, we will allocate 170 published systematic reviews into the intervention group (tweeting arm/Weibo arm) versus the control group (non-tweeting arm). Reviews will be stratified by baseline access activity, defined as high (≥19 views per week, n=14), medium (4.3 to 18.99 views per week, n=72) or low (<4.3 views per week, n=84), based on Google Analytics, which will also be used for evaluating outcomes. The intervention group will have three tweets daily using Hootsuite with a slightly different accompanying text (written by CEA and AB) and a shortened Uniform Resource Locator (URL) to the PLS: a) The review title as it appears in summaries.cochrane.org, b) A pertinent extract from results or discussion sections of the abstract and c) An intriguing question or pithy statement related to the evidence in the abstract. The primary outcome will be: total number of visits to a PLS in 7 days following the tweet. Secondary outcomes will include % new visits, bounce rate, pages per visit, visit duration, page views, unique page views, time on page, entrances, exiting behaviour and country distribution.
Ethics and dissemination: This study does not involve living participants, and uses information available in the public domain. Participants are published systematic reviews, hence, no ethical approval is required. Dissemination will be via Twitter, Weibo and traditional academic means
Effects of multiple heavy metal contamination and repeated phytoextraction by Sedum plumbizincicola on soil microbial properties
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