19,112 research outputs found
Quakes in Solid Quark Stars
A starquake mechanism for pulsar glitches is developed in the solid quark
star model. It is found that the general glitch natures (i.e., the glitch
amplitudes and the time intervals) could be reproduced if solid quark matter,
with high baryon density but low temperature, has properties of shear modulus
\mu = 10^{30~34} erg/cm^3 and critical stress \sigma_c = 10^{18~24} erg/cm^3.
The post-glitch behavior may represent a kind of damped oscillations.Comment: 11 pages, 4 figures (but Fig.3 is lost), a complete version can be
obtained by http://vega.bac.pku.edu.cn/~rxxu/publications/index_P.htm, a new
version to be published on Astroparticle Physic
Grain boundary ferromagnetism in vanadium-doped InO thin films
Room temperature ferromagnetism was observed in InO\,^{\circ}{\rm C}_2_3$ host lattice, thus excluding the existence of secondary phases
of vanadium compounds. Magnetic measurements based on SQUID magnetometry and
magnetic circular dichroism confirm that the magnetism is at grain boundaries
and also in the grains. The overall magnetization originates from the competing
effects between grains and grain boundaries.Comment: 12 pages, 7 figures, 1 table, accepted by Europhysics Letter
Dressed Polyakov loop and flavor dependent phase transitions
The chiral condensate and dressed Polyakov loop at finite temperature and
density have been investigated in the framework of Nf = 2+1 Nambu-Jona-Lasinio
(NJL) model with two degenerate u, d quarks and one strange quark. In the case
of explicit chiral symmetry breaking with physical quark masses, it is found
that the phase transitions for light u, d quarks and s quark are sequentially
happened, and the separation between the transition lines for different flavors
becomes wider and wider with the increase of baryon density. For each flavor,
the pseudo-critical temperatures for chiral condensate and dressed Polyakov
loop differ in a narrow transition range in the lower baryon density region,
and the two transitions coincide in the higher baryon density region.Comment: 9 pages, 9 figures; Version accepted in Phys. Rev.
Comment on "Single-mode excited entangled coherent states"
In Xu and Kuang (\textit{J. Phys. A: Math. Gen.} 39 (2006) L191), the authors
claim that, for single-mode excited entangled coherent states , \textquotedblleft the photon excitations lead to the
decrease of the concurrence in the strong field regime of and
the concurrence tends to zero when ". This is wrong.Comment: 4 apges, 2 figures, submitted to JPA 15 April 200
Fe-based superconductors: unity or diversity?
Does the high temperature superconductivity observed in the newly discovered
iron-pnictide materials represent another example of the same essential physics
responsible for superconductivity in the cuprates, or does it embody a new
mechanism?Comment: Some minor errors in the figure and in the reference in the published
version are corrected. 2 pages, 2 figure
Consumption-led mobilized urbanism: socio-spatial separation in the second-home city of Sanya
Tourism and recreational second home development has increased rapidly in peripheral and lower-tier cities of China in recent years. While tourism-led real estate development has been widely accepted as an effective investment opportunity, it can increase urban segregation and stratification. This pattern is seen in the resort city of Sanya on Hainan Island, China. Sanya’s recreational second homes vary in form and can be categorized into (1) elite-vacation second homes (short stay, private homes), (2) lifestyle-migration second homes (short stay, commercial homes), and (3) retirement-migration second homes (longer term, seasonal homes). Unlike the segregated cities formed by displaced labor migrants in many of China’s cities, seasonal recreational migrants are both economically better-off and are emerging as a dominant political force. The segregated residential spaces created by Sanya’s second home development landscape further limits interaction and social network building between indigenous local residents and part-time recreational migrants. The perceived home space and feelings of place attachment towards Sanya is under drastic change, with locals feeling increasingly displaced. The new mosaic of consumption-led amenity cities in developing economies is one where traditional models of migration-based segregation are reversed.Wealthier second home migrants have the capacity for more political power than local residents, as well as relying more on non-localized social networks and multi-nodal home spaces. Consumption-led mobility is an important determinant in building explanations of socio-spatial segregation and stratification in global cities that are undergoing dramatic development change
Assessment of Long-Term Watershed Management on Reservoir Phosphorus Concentrations and Export Fluxes.
Source water nutrient management to prevent eutrophication requires critical strategies to reduce watershed phosphorus (P) loadings. Shanxi Drinking-Water Source Area (SDWSA) in eastern China experienced severe water quality deterioration before 2010, but showed considerable improvement following application of several watershed management actions to reduce P. This paper assessed the changes in total phosphorus (TP) concentrations and fluxes at the SDWSA outlet relative to watershed anthropogenic P sources during 2005⁻2016. Overall anthropogenic P inputs decreased by 21.5% over the study period. Domestic sewage, livestock, and fertilizer accounted for (mean ± SD) 18.4 ± 0.6%, 30.1 ± 1.9%, and 51.5 ± 1.5% of total anthropogenic P inputs during 2005⁻2010, compared to 24.3 ± 2.7%, 8.8 ± 10.7%, and 66.9 ± 8.0% for the 2011⁻2016 period, respectively. Annual average TP concentrations in SDWSA decreased from 0.041 ± 0.019 mg/L in 2009 to 0.025 ± 0.013 mg/L in 2016, a total decrease of 38.2%. Annual P flux exported from SDWSA decreased from 0.46 ± 0.04 kg P/(ha·a) in 2010 to 0.25 ± 0.02 kg P/(ha·a) in 2016, a decrease of 44.9%. The success in reducing TP concentrations was mainly due to the development of domestic sewage/refuse collection/treatment and improved livestock management. These P management practices have prevented harmful algal blooms, providing for safe drinking water
Memory-Based Snowdrift Game on Networks
We present a memory-based snowdrift game (MBSG) taking place on networks. We
found that, when a lattice is taken to be the underlying structure, the
transition of spatial patterns at some critical values of the payoff parameter
is observable for both 4 and 8-neighbor lattices. The transition points as well
as the styles of spatial patterns can be explained by local stability analysis.
In sharp contrast to previously reported results, cooperation is promoted by
the spatial structure in the MBSG. Interestingly, we found that the frequency
of cooperation of the MBSG on a scale-free network peaks at a specific value of
the payoff parameter. This phenomenon indicates that properly encouraging
selfish behaviors can optimally enhance the cooperation. The memory effects of
individuals are discussed in detail and some non-monotonous phenomena are
observed on both lattices and scale-free networks. Our work may shed some new
light on the study of evolutionary games over networks.Comment: 6 pages, 6 figures, to be published in Phys. Rev.
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