A New Phase Transition Related to the Black Hole's Topological Charge

The topological charge $\epsilon$ of AdS black hole is introduced in Ref.[1,2], where a complete thermodynamic first law is obtained. In this paper, we investigate a new phase transition related to the topological charge in Einstein-Maxwell theory. Firstly, we derive the explicit solutions corresponding to the divergence of specific heat $C_{\epsilon}$ and determine the phase transition critical point. Secondly, the $T-r$ curve and $T-S$ curve are investigated and they exhibit an interesting van der Waals system's behavior. Critical physical quantities are also obtained which are consistent with those derived from the specific heat analysis. Thirdly, a van der Waals system's swallow tail behavior is observed when $\epsilon>\epsilon_{c}$ in the $F-T$ graph. What's more, the analytic phase transition coexistence lines are obtained by using the Maxwell equal area law and free energy analysis, the results of which are consistent with each other.Comment: 11 pages, 5 figure

The influence of returnee technology executives on enterprise innovation: the innovation patent data of global exchange market listed companies

In this paper, the innovation patent data of 344 Chinese Global Exchange Market (GEM) listed companies from 2014 to 2018 is manually collected, and the effect of returnee technology executives (RTEs) on enterprise innovativeness is examined based on the empirical theory of the high ladder team. The study finds that RTEs promote enterprise innovation and that this effect persists after controlling for endogeneity and self-selection problems. By comparing the difference in the effect of RTEs on breakthrough innovation and non-breakthrough innovation, the study found that RTEs had a more significant role in promoting enterprise breakthrough innovation. Furthermore, through executive group analysis, it is found that Returnee Technology Chief Executive Officers (CEOs) have more potently positive effect on promoting enterprise innovation especially breakthrough innovation and RTEs exert greater prominence in fostering innovation in companies across developed coastal areas. The research theoretically expands and deepens the investigation on the rapport between enterprise executive characteristics and innovation, highlights the importance of the human capital of overseas returnees in practice, and has a certain guiding significance for enterprise talent introduction policies

Attractive Interaction between Vortex and Anti-vortex in Holographic Superfluid

Annihilation process of a pair of vortices in holographic superfluid is numerically simulated. The process is found to consist of two stages which are amazingly separated by vortex size $2r$. The separation distance $\delta(t)$ between vortex and anti-vortex as a function of time is well fitted by $\alpha (t_{0}-t)^{n}$, where the scaling exponent $n=1/2$ for $\delta (t)>2r$, and $n=2/5$ for $\delta(t)<2r$. Then the approaching velocity and acceleration as functions of time and as functions of separation distance are obtained. Thus the attractive force between vortex and anti-vortex is derived as $f(\delta)\propto 1/\delta^{3}$ for the first stage, and $f(\delta)\propto 1/\delta^{4}$ for the second stage. In the end, we explained why the annihilation rate of vortices in turbulent superfluid system obeys the two-body decay law when the vortex density is low.Comment: 14 pages, 5 figure

Anti-depressant-like effect of curculigoside isolated from Curculigo orchioides Gaertn root

Purpose: To investigate the anti-depressant-like activity of curculigoside from Curculigo orchioides Gaertn and its underlying mechanism(s).Methods: Antidepressant-like activity was determined in mice through forced swimming test (FST), tail suspending test (TST), and open field test (OFT). Mechanism of action was investigated by measuring levels of dopamine (DA), norepinephrine (NE), and 5-hydroxytryptamine (5-HT) in chronic mild stress (CMS) rats using high-performance liquid chromatography-electron capture detector (HPLC-ECD). Western blotting was used to investigate the effect of curculigoside on the expression of brain-derived neurotrophic factor (BDNF) protein in rats.Results: In FST and TST, treatment of mice with curculigoside (10, 20, 40 mg/kg, p.o.) significantly reduced immobility time, which was, however, unaffected by locomotor activity when assessed in the OFT. The treatment led to significant increases in DA, NE and 5-HT, and up-regulation of BDNF protein expression in the hippocampus of the CMS rats.Conclusion: These results demonstrate that curculigoside exerts significant anti-depressant-like activity on mice, the mechanism of which involves increase in the levels of DA, NE, 5-HT, and up-regulation of BDNF expression. Thus, curculigoside can be considered a potential drug candidate for the treatment of depressive disorders.Keywords: Curculigo orchioides Gaertn, Curculigoside, Antidepressant-like activity, Behavioral studie

Pride, prejudice and pragmatism: family language policies in the UK

In this study, we examine how mobility and on-going changes in sociocultural contexts impact family language policy (FLP) in the UK. Using a questionnaire and involving 470 transnational families across the UK, our study provides a descriptive analysis of different family language practices in England and establishes how attitudes influence the different types of FLP in these families. Complementing the descriptive analysis, we use interview data to understand the driving forces behind the different types of language practices and language management activities, and explore how ideological constructs of ‘pride’, ‘prejudice’ and ‘pragmatism’ are directly related to negative or positive attitudes towards the development of children’s heritage language. The findings indicate that migration trajectories, social values, raciolinguistic policing in schools, and linguistic loyalty have shaped family decisions about what languages to keep and what languages to let go. Our paper responds to the linguistic and demographic changes in British society, and makes an important contribution to our knowledge about multilingual development of children in transnational families. Critically, this study shows that FLPs alone cannot save the minority languages; institutionally sanctioned language practices and ideologies have to make a move from limiting the use of these languages in educational contexts to legitimising them as what they are: linguistic resources and languages of pride