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1.
Phys Rev Lett ; 131(22): 221602, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-38101353

RESUMO

Using holographic duality, we investigate the impact of finite temperature on the instability and splitting patterns of quadruply quantized vortices, providing the first-ever analysis in this context. Through linear stability analysis, we reveal the occurrence of two consecutive dynamical transitions. At a specific low temperature, the dominant unstable mode transitions from the twofold rotational symmetry mode to the threefold one, followed by a transition from the threefold one to the fourfold one at a higher temperature. As the temperature is increased, we also observe the fivefold and sixfold rotational symmetry unstable modes get excited successively. Employing the full nonlinear numerical simulations, we further demonstrate that these two novel dynamical transitions, along with the temperature-induced instabilities for the fivefold and sixfold rotational symmetry modes, can be identified by examining the resulting distinct splitting patterns, which offers a promising route for the experimental verification in the cold atom gases.

2.
Phys Rev Lett ; 131(22): 221601, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-38101390

RESUMO

Driving a system out of equilibrium enriches the paradigm of spontaneous symmetry breaking, which could then take place not only in space but also in time. The interplay between temporal and spatial symmetries, as well as symmetries from other internal degrees of freedom, can give rise to novel nonequilibrium phases of matter. In this Letter, we investigate a driven-dissipative superfluid model using holographic methods and reveal the existence of a spacetime supersolid (STS) phase that concomitantly breaks the time translation, spatial translation, and the internal U(1) symmetry. The holographic methods naturally include finite temperature effects, which enables us to explore the complex phase diagram of this model and observe a cascade of out-of-equilibrium phase transitions from the STS phase to a synchronized superfluid phase, and finally to a normal fluid phase, by increasing the temperature.

3.
Ying Yong Sheng Tai Xue Bao ; 31(10): 3473-3479, 2020 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-33314837

RESUMO

Shading is one of the important strategies to protect seedlings of Paeonia lactiflora. The effects of shading treatments on seedling growth and mineral accumulation of Duolun P. lactiflora were investigated in a greenhouse experiment to provide guidance for P. lactiflora cultivation. One week after emergence, seedlings were treated with 20%, 40%, 60% or 80% shading for two months, with no-shading as the control (CK). The results showed that shading treatments significantly increased plant height by 19.9%, 31.1%, 52.9%, and 63.7%, respectively. However, shading significantly reduced the root mass ratio and root to shoot ratio by 21.5%, 23.6%, 29.2%, 41.8% and 40.6%, 44.0%, 50.9%, 63.2%, respectively. Moreover, 40%, 60% and 80% shading significantly increased specific leaf area by 77.0%, 84.1% and 65.2%, and significantly increased chlorophyll content by 92.3%, 128.7%, 98.1%, and increased carotenoid content by 86.9%, 113.1% and 90.5%, respectively. The treatments of 40%, 60%, and 80% shading significantly decreased root biomass by 61.4%, 74.3% and 78.6%, respectively. Compared with CK, 20%, 40% and 80% shading, the 60% shading treatment increased root phosphorus content by 245.7%, 65.9%, 40.5% and 10.3%, increased potassium content by 102.9%, 131.7%, 57.0%, 63.3% and magnesium content by 131.3%, 55.1%, 40.4%, 7.7%, respectively. 60% shading was an appropriate shading intensity for P. lactiflora seedling cultivation based on local conditions in Duolun.


Assuntos
Paeonia , Plântula , Clorofila , Minerais , Folhas de Planta
4.
Front Psychol ; 11: 581397, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33250821

RESUMO

Grounded on the social exchange theory (SET), social cognitive theory (SCT), and self-determination theory (SDT), this study aims to explore the mediating role of self-efficacy (SE) and work engagement (WE) on the effect of social support (SS) on job satisfaction (JS) among Chinese ethnic minority kindergarten teachers (KTs). The results show that: (1) SS has a directly significant effect on JS; (2) WE mediates the relationship between SS and JS; and (3) SE mediates the relationship between SS and WE. Although the mediation of SE on the relationship between SS and JS is not found, the posited multiple mediations of SE and WE on the relationship between SS and JS are totally accepted. The results reveal that SS mainland Chinese ethnic minority KTs received can not only have a direct effect on JS but also have an indirect impact through the one-path mediating role of WE and the chain mediating role of SE and WE. The results suggest that governments, supervisors, and sponsors should work together to provide ethnic minority KTs with more prioritized SS from both cultural psychology and financial material and opportunities for facilitating professional knowledge and skills in order to enhance their SE, inspire their WE, and eventually accumulate their JS.

5.
Phys Rev Lett ; 124(3): 031601, 2020 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-32031857

RESUMO

By holographic duality, we identify a novel dynamical phase transition which results from the temperature dependence of nonequilibrium dynamics of dark solitons in a superfluid. For a nonequilibrium superfluid system with an initial density of dark solitons, there exists a critical temperature T_{d}, above which the system relaxes to equilibrium by producing sound waves, while below which it goes through an intermediate phase with a finite density of vortex-antivortex pairs. In particular, as T_{d} is approached from below, the density of vortex pairs scales as (T_{d}-T)^{γ} with the critical exponent γ=1/2.

6.
Anim Cogn ; 18(4): 931-6, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25805651

RESUMO

The evolutionary origin of human right-handedness remains unclear. Many factors such as emotion and tool use have been implicated in primate handedness evolution. With regard to emotional lateralization, most related research focuses on facial asymmetry and behavioral laterality under the non-social context, whereas few studies investigate social laterality. This study, for the first time, investigates the effect of target animacy on hand preference in Old World monkeys, compares our findings with previous related studies in great apes and humans, and aids in filling the knowledge gap on primate handedness evolution. Nine captive northern pig-tailed macaques (Macaca leonina) were chosen as focal subjects in this study. There was no group-level handedness for both animate and inanimate targets. No significant interaction was found between lateral hand use and target animacy. Left-hand use was more frequent than right-hand use for animate targets, whereas right-hand use was more frequent than left-hand use for inanimate targets, both of which demonstrate no significant level. On the whole, northern pig-tailed macaques showed a similar tendency as that in great apes and humans. Regarding handedness linked with emotive stimuli, it is likely that Old World monkeys, great apes and humans evolved from a common ancestor.


Assuntos
Lateralidade Funcional , Macaca/psicologia , Animais , Comportamento Animal , Evolução Biológica , Feminino , Masculino , Gravação em Vídeo
7.
Phys Rev Lett ; 113(9): 091602, 2014 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-25215974

RESUMO

We construct a gravity dual for charge density waves (CDWs) in which the translational symmetry along one spatial direction is spontaneously broken. Our linear perturbation calculation on the gravity side produces the frequency dependence of the optical conductivity, which exhibits the two familiar features of CDWs, namely, the pinned collective mode and gapped single-particle excitation. These two features indicate that our gravity dual also provides a new mechanism to implement the metal to insulator phase transition by CDWs, which is further confirmed by the fact that dc conductivity decreases with the decreased temperature below the critical temperature.

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