Goodbye, Mother

https://digitalcommons.library.umaine.edu/mmb-me/1324/thumbnail.jp

Self-Assembly on a Cylinder: A Model System for Understanding the Constraint of Commensurability

A crystal lattice, when confined to the surface of a cylinder, must have a periodic structure that is commensurate with the cylinder circumference. This constraint can frustrate the system, leading to oblique crystal lattices or to structures with a chiral seam known as a "line slip" phase, neither of which are stable for isotropic particles in equilibrium on flat surfaces. In this study, we use molecular dynamics simulations to find the steady-state structure of spherical particles with short-range repulsion and long-range attraction far below the melting temperature. We vary the range of attraction using the Lennard-Jones and Morse potentials and find that a shorter-range attraction favors the line-slip. We develop a simple model based only on geometry and bond energy to predict when the crystal or line-slip phases should appear, and find reasonable agreement with the simulations. The simplicity of this model allows us to understand the influence of the commensurability constraint, an understanding that might be extended into the more general problem of self-assembling particles in strongly confined spaces.Comment: 12 pages, 9 figures. Submitted for publication, 201

Milburn Belles

https://digitalcommons.library.umaine.edu/mmb-me/1325/thumbnail.jp

Determination of the Superconductor-Insulator Phase Diagram for One-Dimensional Wires

We establish the superconductor-insulator phase diagram for quasi-one dimensional wires by measuring a large set of MoGe nanowires. This diagram is consistent with the Chakravarty-Schmid-Bulgadaev phase boundary, namely with the critical resistance being equal to R_Q = h/4e^2. We find that transport properties of insulating nanowires exhibit a weak Coulomb blockade behavior.Comment: 5 pages, 4 figure

Negishi Coupling of Pteridine-O-sulfonates

Negishi coupling of pteridine-O-sulfonate with Zn-aryls is reported. Hydrolysis of the protecting groups with 1M NH3 gave the 6-subustituted 2,4-diaminopteridine while hydrolysis with 1 M NaOH gave the 6-subsituted pterin.KEYWORDS Pteridine, pterin, Negishi coupling

Back to Childhood\u27s Home and Mother

https://digitalcommons.library.umaine.edu/mmb-vp/4439/thumbnail.jp

Waltz Me Till I\u27m Dreamy

https://digitalcommons.library.umaine.edu/mmb-vp/5557/thumbnail.jp

At Sunset

https://digitalcommons.library.umaine.edu/mmb-me/1322/thumbnail.jp