Upconversion nanocrystals NCs of NaYF4:Yb,Ln Ln=Er and Tm in cubic and hexagonal phases were synthesized in oleic acid OA and/or trioctylphosphine TOP with octadecene ODE via a thermolysis method. Only cubic-phase NCs were obtained in OA/ODE and TOP/ODE solvents; on the other hand, the hexagonal-phase NCs resulted in OA/TOP/ODE. The phase transition from cubic to hexagonal was induced by a liga...

In this talk, we first introduce the concept of the lattice discrete Fourier transform (lattice DFT). Then we build a theory of matrix-vector division with remainder to represent multi-dimensional integer indices. As an application, a divide-and-conquer technique is developed for fast evaluation of the hexagonal lattice DFT, which is finally reduced to a variety of the Cooley-Tukey algorithms. ...

Virus replication inhibitory peptide (carbobenzoxy-D-Phe-L-PheGly) was shown to be a potent specific inhibitor of the replication of paramyxovirus and myxovirus (Richardson, Scheid and Choppin (1980), Virology 105, 205-222). This peptide inhibits the membrane fusing activity of a viral glycoprotein. Many agents which promote the formation of the hexagonal phase in membranes also accelerate memb...

In many mathematical models for pattern formation, a regular hexagonal pattern is stable in an infinite region. However, laboratory and numerical experiments are carried out in finite domains, and this imposes certain constraints on the possible patterns. In finite rectangular domains, it is shown that a regular hexagonal pattern cannot occur if the aspect ratio is rational. In practice, it is ...

We studied the interaction between a single hydrogen atom and a single graphene using classical molecular dynamics simulation with modified Brenner REBO potential. Three interactions, which are adsorption, reflection, penetration, were observed. Overhang structure appears and creates an adsorption site on the backside of the graphene. It is considered that backside adsorption occurs under the t...

In the recent work by Khatua et al. (Khatua, S.; Roy, D. R.; Bultinck, P.; Bhattacharjee, M.; Chattaraj, P. K. Phys. Chem. Chem. Phys.2008, 10, 2461-2474) the synthesis and structure of a fac-trioxo molybdenum metalloligand and its sodium complex containing 1D hexagonal chains of sodium ions was reported. In the same paper, the aromaticity of hexagonal Na clusters was quantified by means of the...

Geospatial data is gathered through a variety of different methods. The integration and handling of such data-sets within a Digital Earth framework are very important in many aspects of science and engineering. One means of addressing these tasks is to use a Discrete Global Grid System and map points of the Earth’s surface to cells. An indexing mechanism is needed to access the data and handle ...

A 1-2 model configuration is a subgraph of the hexagonal lattice, in which the edgedegree of each vertex is either 1 or 2. We prove that for any translation invariant Gibbs measure of the 1-2 model configurations on the whole-plane hexagonal lattice, almost surely there are no infinite paths. Using a measure-preserving correspondence between 1-2 model configurations on the hexagonal lattice and...

Laboratory experiments to determine the preferred orientation of free-falling hexagonal prisms were performed at Reynolds numbers appropriate to falling ice crystals in the atmosphere. Hexagonal plates orient with their c axis vertical for aspect ratios < 0.9, whilst hexagonal columns fall with their c axis horizontal. A secondary alignment is also observed: regular hexagonal columns fall prefe...

We produce an explicit parameterization of well-rounded sublattices of the hexagonal lattice in the plane, splitting them into similarity classes. We use this parameterization to study the number, the greatest minimal norm, and the highest signal-to-noise ratio of well-rounded sublattices of the hexagonal lattice of a fixed index. This investigation parallels earlier work by Bernstein, Sloane, ...