Properties of collective Rabi oscillations with two Rydberg atoms

Motivated by experimental advances that the collective excitation of two Rydberg atoms was observed, we provide an elaborate theoretical study for the dynamical behavior of two-atom Rabi oscillations. In the large-intermediate-detuning case, the two-photon Rabi oscillation is found to be significantly affected by the strength of the interatomic van der Waals interaction. With a careful comparison of the exact numbers and values of the oscillation frequency, we propose a new way to determine the strength of excitation blockade, agreeing well with the previous universal criterion for full, partial, and no blockade regions. In the small-intermediate-detuning case, we find a blockade-like effect, but the collective enhancement factor is smaller than ^(1/2) due to the quantum interference of double optical transitions involving the intermediate state.Moreover, a fast two-photon Rabi oscillation in ns timescale is manifested by employing intense lasers with an intensity of ~MW/cm^2, offering a possibility of ultrafast control of quantum dynamics with Rydberg atoms.

Multidifferentiation potential of dental-derived stem cells

Tooth-related diseases and tooth loss are widespread and are a major public health issue.The loss of teeth can affect chewing,speech,appearance and even psychology.Therefore,the science of tooth regeneration has emerged,and attention has focused on tooth regeneration based on the principles of tooth development and stem cells combined with tissue engineering technology.As undifferentiated stem cells in normal tooth tissues,dental mesenchymal stem cells(DMSCs),which are a desirable source of autologous stem cells,play a significant role in tooth regeneration.Researchers hope to reconstruct the complete tooth tissues with normal functions and vascularization by utilizing the odontogenic differentiation potential of DMSCs.Moreover,DMSCs also have the ability to differentiate towards cells of other tissue types due to their multipotency.This review focuses on the multipotential capacity of DMSCs to differentiate into various tissues,such as bone,cartilage,tendon,vessels,neural tissues,muscle-like tissues,hepatic-like tissues,eye tissues and glands and the influence of various regulatory factors,such as non-coding RNAs,signaling pathways,inflammation,aging and exosomes,on the odontogenic/osteogenic differentiation of DMSCs in tooth regeneration.The application of DMSCs in regenerative medicine and tissue engineering will be improved if the differentiation characteristics of DMSCs can be fully utilized,and the factors that regulate their differentiation can be well controlled.

Surface effect induced phase transformation by Mn removal during annealing and its textures in cold-rolled high manganese transformation-induced plasticity steel

The surface effect induced transformation texture during vacuum annealing of cold-rolled high manganese transformation-induced plasticity(TRIP)steels was studied.Due to Mn removal occurring at the surface layer,γ→δdiffusional phase transformation leads to the formation of hard pancake-shaped ferrite grains due to solution strengthening at the surface and the centre layer remains as austenite+martensite after annealing.In the case of slow heating,{112}/{111}<110>textures for the surface ferrite were strengthened with the increase in temperature and holding time,indicating an inheritance of rolling textures.By increasing the heating rate of annealing,the rotated cube texture was developed in surface ferrite.This kind of multiphase sandwich structure with hard ferrite surface layer and tough austenite dominant centre can increase tensile strength and should also improve deep drawing properties,therefore providing new possibility of controlling properties for the application of high manganese TRIP steel.