3,419 research outputs found
The Role of Chaos in One-Dimensional Heat Conductivity
We investigate the heat conduction in a quasi 1-D gas model with various
degree of chaos. Our calculations indicate that the heat conductivity
is independent of system size when the chaos of the channel is strong enough.
The different diffusion behaviors for the cases of chaotic and non-chaotic
channels are also studied. The numerical results of divergent exponent
of heat conduction and diffusion exponent are in consistent with the
formula . We explore the temperature profiles numerically and
analytically, which show that the temperature jump is primarily attributed to
superdiffusion for both non-chaotic and chaotic cases, and for the latter case
of superdiffusion the finite-size affects the value of remarkably.Comment: 6 pages, 7 figure
Electron-nuclear entanglement in the cold lithium gas
We study the ground-state entanglement and thermal entanglement in the
hyperfine interaction of the lithium atom. We give the relationship between the
entanglement and both temperature and external magnetic fields.Comment: 7 pages, 3 figure
Heat conductivity in the presence of a quantized degree of freedom
We propose a model with a quantized degree of freedom to study the heat
transport in quasi-one dimensional system. Our simulations reveal three
distinct temperature regimes. In particular, the intermediate regime is
characterized by heat conductivity with a temperature exponent much
greater than 1/2 that was generally found in systems with point-like particles.
A dynamical investigation indicates the occurrence of non-equipartition
behavior in this regime. Moreover, the corresponding Poincar\'e section also
shows remarkably characteristic patterns, completely different from the cases
of point-like particles.Comment: 7 pages, 4 figure
Medium effects on the selection of sequences folding into stable proteins in a simple model
We study the medium effects on the selection of sequences in protein folding
by taking account of the surface potential in HP-model. Our analysis on the
proportion of H and P monomers in the sequences gives a direct interpretation
that the lowly designable structures possess small average gap. The numerical
calculation by means of our model exhibits that the surface potential enhances
the average gap of highly designable structures. It also shows that a most
stable structure may be no longer the most stable one if the medium parameters
changed.Comment: 4 pages, 4 figure
Injection method of barrier bucket supported by off-aligned electron cooling for CRing of HIAF
A new accelerator complex, HIAF (the High Intensity Heavy Ion Accelerator
Facility), has been approved in China. It is designed to provide intense
primary and radioactive ion beams for research in high energy density physics,
nuclear physics, atomic physics as well as other applications. In order to
achieve a high intensity of up to 5e11 ppp 238U34+, the Compression Ring
(CRing) needs to stack more than 5 bunches transferred from the Booster Ring
(BRing). However, the normal bucket to bucket injection scheme can only achieve
an intensity gain of 2, so an injection method, fixed barrier bucket (BB)
supported by electron cooling, is proposed. To suppress the severe space charge
effect during the stacking process, off-alignment is adopted in the cooler to
control the transverse emittance. In this paper, simulation and optimization
with the BETACOOL program are presented
The Side-Effects of the Space Charge Field Introduced by Hollow Electron Beam in the Electron Cooler of CSRm
Electron cooler is used to improve the quality of the beam in synchrotron,
however it also introduces nonlinear electromagnetic field, which cause
tuneshift, tunespread and may drive resonances leading to beam loss. In this
paper the tuneshift and the tunespread caused by nonlinear electromagnetic
field of the hollow electron beam was investigated, and the resonance driving
terms of the nonlinear electromagnetic field was analysed. The differences were
presented comparing with the solid electron beam. The calculations were
performed for ions of energy 1.272MeV stored in CSRm, using the
parameters given in table1. The conclusion is that in this situation nonlinear
field caused by the hollow electron beam do not lead to serious resonances
Insights into the Ecological Roles and Evolution of Methyl-Coenzyme M Reductase-Containing Hot Spring Archaea
Several recent studies have shown the presence of genes for the key enzyme associated with archaeal methane/alkane metabolism, methyl-coenzyme M reductase (Mcr), in metagenome-assembled genomes (MAGs) divergent to existing archaeal lineages. Here, we study the mcr-containing archaeal MAGs from several hot springs, which reveal further expansion in the diversity of archaeal organisms performing methane/alkane metabolism. Significantly, an MAG basal to organisms from the phylum Thaumarchaeota that contains mcr genes, but not those for ammonia oxidation or aerobic metabolism, is identified. Together, our phylogenetic analyses and ancestral state reconstructions suggest a mostly vertical evolution of mcrABG genes among methanogens and methanotrophs, along with frequent horizontal gene transfer of mcr genes between alkanotrophs. Analysis of all mcr-containing archaeal MAGs/genomes suggests a hydrothermal origin for these microorganisms based on optimal growth temperature predictions. These results also suggest methane/alkane oxidation or methanogenesis at high temperature likely existed in a common archaeal ancestor
Free field realization of the exceptional current superalgebra \hat{D(2,1;\a)}_k
The free-field representations of the D(2,1;\a) current superalgebra and
the corresponding energy-momentum tensor are constructed. The related screening
currents of the first kind are also presented.Comment: Latex file, 10 page
How special is special interest tourism – and how special are special interest tourists? A perspective article in a Chinese context
Special interest tourism has emerged as a valuable niche market for tourism destinations in the past decade. However, tourism scholars have generally struggled to answer McKercher and Chan’s [2005. How special is special interest tourism? Journal of Travel Research, 44(1), 21–31] question, ‘How special is special interest tourism?’ Such ambiguity extends to the related enquiry, ‘How special are special interest tourists?’, in attempting to define special interest tourists. This perspective research letter discusses these questions in terms of Chinese outbound tourism. Based upon the reflection of previous research, the authors’ thoughts and ongoing research in this area, knowledge gaps are identified and research directions for scholars who are also interested special interest tourism are offered
- …
