Triple points and phase transitions of D-dimensional dyonic Ad S black holes with quasitopological electromagnetism in Einstein–Gauss–Bonnet gravity

By considering the negative cosmological constant Λ as a thermodynamic pressure, we study the thermodynamics and phase transitions of the D-dimensional dyonic Ad S black holes(BHs) with quasitopological electromagnetism in Einstein–Gauss–Bonnet(EGB) gravity. The results indicate that the small/large BH phase transition that is similar to the van der Waals(vdW) liquid/gas phase transition always exists for any spacetime dimensions. Interestingly, we then find that this BH system exhibits a more complex phase structure in 6-dimensional case that is missed in other dimensions.Specifically, it shows for D = 6 that we observed the small/intermediate/large BH phase transitions in a specific parameter region with the triple point naturally appeared. Moreover, when the magnetic charge turned off, we still observed the small/intermediate/large BH phase transitions and triple point only in 6-dimensional spacetime, which is consistent with the previous results. However, for the dyonic Ad S BHs with quasitopological electromagnetism in Einstein–Born–Infeld(EBI) gravity, the novel phase structure composed of two separate coexistence curves observed by Li et al. [Phys. Rev. D105 104048(2022)] disappeared in EGB gravity. This implies that this novel phase structure is closely related to gravity theories, and seems to have nothing to do with the effect of quasitopological electromagnetism. In addition, it is also true that the critical exponents calculated near the critical points possess identical values as mean field theory. Finally, we conclude that these findings shall provide some deep insights into the intriguing thermodynamic properties of the dyonic Ad S BHs with quasitopological electromagnetism in EGB gravity.

MEIR-KEELER TYPE CONTRACTIONS FOR TRIPLED FIXED POINTS

In 2011, Berinde and Borcut [6] introduced the notion of tripled fixed point in partially ordered metric spaces. In our paper, we give some new tripled fixed point theorems by using a generalization of Meir-Keeler contraction：

Mode Interaction at a Triple Zero Point of O(2) symmetric Nonlinear Systems with Two Parameters

We consider a triple zero point of nonlinear equations with O(2 symmetry, where the Jacobian has a zero eigenvalue of geometric multiplicity one and algebraic multiplicity three. We show that this triple zero point exhibits a new bifurcation phenomenon, that is, a mode interaction of the following three paths: bifurcation points from steady states, steady states and rotating waves to standing waves, rotating waves and modulated rotating waves respectively.

Microstructural features of Mg-8%Sn alloy and its correlation with mechanical properties

The aim of this investigation is to establish a structure-property correlation of Mg-8%Sn alloys aged at different time interval.The alloy under the present investigation was aged at elevated(200℃)temperature for various holding period.Differently aged alloys show retention of intermetallic phases after ageing,but in different area fraction of the same with ageing time.Mechanical properties evaluation and corresponding microstructural characterizations were performed to correlate their strength and ductility properties with their microstructural features(i.e.,grain size,grain connectivity and the area fraction of intermetallic phases).

Resolving the Routine Presence of Kyanite, Andalusite and Sillimanite across a Region using Foliation Intersection/Inflection Axes Preserved in Porphyroblasts, Petrographic Observations and Thermobarometry

Constraints from P-T pseudosections （MnNCKFMASH system）, foliation intersection/ inflection axes preserved in porphyroblasts （FIAs）, mineral assemblages and textural relationships for rocks containing all three Al2 SiO5 polymorphs indicate a kyanite→ andalusite→ sillimanite sequential formation at different times rather than stable coexistence at the Al2SiO5 triple point. All three Al2SiO5 polymorphs grew in the Chl, Bt, Ms, Grt, St, Pl and Crd bearing Ordovician Clayhole Schist in Balcooma, northeastern Australia separately along a looped P-T-t-D path that swaps from clockwise to anticlockwise in the tectono-metamorphic history of the region. Kyanite grew during crustal thickening in an Early Silurian Orogenic event followed by decompression/heating, andalusite and fibrolitic sillimanite growth during Early Devonian exhumation.

POSITIVE SOLUTIONS FOR SOME 1-DIMENSIONAL BOUNDARY VALUE PROBLEMS OF LAPLACE-TYPE

This paper deals with the existence of triple positive solutions for the 1-dimensional equation of Laplace-type （φ（x′（t）））′＋q（t）f（t,x（t）,x′（t））=0,t∈（0,1）,subject to the following boundary condition：a1φ（x（0））-a2φ（x＇（0））=0,a3φ（x（1））＋a4φ（x＇（1））=0,where φ is an odd increasing homogeneous homeomorphism. By using a new fixed point theorem, sufficient conditions are obtained that guarantee the existence of at least three positive solu- tions. The emphasis here is that the nonlinear term f is involved with the first order derivative explicitly.

Some Random Coincidence Point and Common Fixed Point Results in Cone Metric Spaces Over Banach Algebras

In this paper,we obtain some tripled common random fixed point and tripled random fixed point theorems with several generalized Lipschitz constants in such spaces.We consider the obtained assertions without the assumption of normality of cones.The presented results generalize some coupled common fixed point theorems in the existing literature.

Numerical Investigation of the Influence of Fuel Concentration Gradient on Propane/Oxygen Detonation Propagation

In this paper,one-and two-dimensional numerical simulations are carried out to study the effects of fuel concentration gradients(such as steep,intermediate and shallow)on the detonation wave behavior.The equivalent ratio range of detonation propagation,the quenching mechanism and the change of cell size are discussed in detail.The simulation results show,as the fuel concentration gradient increases,the detonation wavefront decays faster and decouples into a leading shock and a following flame at equivalence ratios of 0.68,0.64 and 0.62,respectively.Moreover,there are two modes of the quenching mechanism.One occurs in the steep gradient that the detonation wave fails rapidly.The O_(2)in front of the detonation wave passes through the detonation wave and forms some unburned O_(2)pockets.The unburned pockets are affected by the marginal walls and reduce the heat release.The other occurs in the intermediate and shallow gradients that more triple points will survive in the flow field,which leads to a difference in the propagation speed of the detonation wavefront.This makes the detonation wavefront bent and deformed.The unburned O_(2)pockets are affected by the strong instability near the triple points and show different distribution characteristics compared with the steep gradient,which may be helpful to the detonation propagation.In addition,as the fuel concentration gradient increases,the triple points moving toward the wall gradually disappear while the triple points that move toward the center can continue to survive,which leads to the gradual increase in cell size and irregularity of the cell structure.

Reflection of a moving shock wave over an oblique shock wave

The reflection of a moving shock wave over a wedge immersed in a still gas and the reflection of a wed ge induced steady shock wave over symmetrical and asymmetrical reflecting surfaces have received intensive considerations since more than 70 years ago.Here we consider a different shock reflection problem—reflection of a moving shock wave over an initially steady oblique shock wave induced by a wedge immersed in supersonic flow.For the flow condition we considered,five moving triple points,with each connecting an incident shock wave,a reflected shock wave and a Mach stem,are identified.By using the reference frame co-moving with each triple point,the type of each shock wave of this triple point is clarified.The present study is significant in that it treats a new shock reflection problem leading to a new shock reflection configuration and showing potential applications in supersonic flow with unsteady shock interaction.