University of Arkansas

About: University of Arkansas is a education organization based out in Fayetteville, Arkansas, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 17225 authors who have published 33329 publications receiving 941102 citations. The organization is also known as: Arkansas & UA.

The natural emergence of reasoning about the afterlife as a developmental regularity

Abstract: Participants were interviewed about the biological and psychological functioning of a dead agent. In Experiment 1, even 4- to 6-year-olds stated that biological processes ceased at death, although this trend was more apparent among 6- to 8-year-olds. In Experiment 2, 4- to 12-year-olds were asked about psychological functioning. The youngest children were equally likely to state that both cognitive and psychobiological states continued at death, whereas the oldest children were more likely to state that cognitive states continued. In Experiment 3, children and adults were asked about an array of psychological states. With the exception of preschoolers, who did not differentiate most of the psychological states, older children and adults were likely to attribute epistemic, emotional, and desire states to dead agents. These findings suggest that developmental mechanisms underlie intuitive accounts of dead agents' minds.

Opening four-wave mixing and six-wave mixing channels via dual electromagnetically induced transparency windows.

Abstract: Highly efficient four-wave mixing (FWM) and six-wave mixing (SWM) processes can coexist in a four-level Y-type atomic system due to atomic coherence The simultaneously opened dual electromagnetically induced transparency windows in this four-level atomic system allow observation of these two nonlinear optical processes at the same time, which enables detailed studies of the interplay between the FWM and SWM processes Three-photon and five-photon destructive interferences are also observed

Surface Ligand Dynamics in Growth of Nanocrystals

Abstract: Amine ligands were identified to bond on the surface of CdSe nanocrystals in a dynamic fashion under elevated temperatures in the reproducible growth domain of the specific designed growth reactions. The surface ligand dynamics was found to strongly depend on the growth temperature, the ligand concentration, and the ligand chain length. The strong chain-length dependence was originated from the interligand interactions in the ligand monolayer of a nanocrystal, provided fatty amines being weak ligands for CdSe nanocrystals. When the growth reaction was above the boiling point of an amine ligand, the surface ligand dynamics was violent, a quasi-gas-phase state, indicated by strong temperature-dependent and fast growth rates of the nanocrystals. Approximately below its boiling point, a significantly weak temperature dependence of the growth rate of the nanocrystals associated with the quasi-liquid state of the surface ligands was observed. A direct result of studying the surface ligand dynamics of this well-established nanocrystal system was the formation of high-quality CdSe nanocrystals under much reduced temperature, 150 degrees C, in comparison to the standard 250-350 degrees C temperature range. This was achieved by using fatty amines with a short hydrocarbon chain at a low ligand concentration in the solution. Preliminary results indicate that a similar temperature (160 degrees C) also worked for the growth of InP nanocrystals.

Size/shape-controlled synthesis of colloidal CdSe quantum disks: ligand and temperature effects.

Abstract: Size/shape-controlled colloidal CdSe quantum disks with zinc-blende (cubic) crystal structure were synthesized using air-stable and generic starting materials. The colloidal CdSe quantum disks were approximately square, and their lateral dimensions were varied between 20 and 100 nm with the thickness controlled between 1 and 3 nm, which resulted in sharp and blue-shifted UV−vis and PL peaks due to one-dimensional quantum confinement. The quantum disks were grown with either ⟨001⟩ or ⟨111⟩ direction, polar directions in the single crystalline disks, as the short axis, and both basal planes were terminated with Cd ions. These surface Cd ions were passivated with negatively charged fatty acid ligands to neutralize the net positive charges caused by the excess monolayer of Cd ions. The coordination of the Cd ions and carboxylate groups further enabled the close-packing monolayer of fatty acid ligands on each basal plane. The close packing of the hydrocarbon chains of fatty acids dictated the up temperature li...