On the use of anomeric hydroxylamines in the reverse-Cope cyclisation

Reverse-Cope cyclisations of unsaturated hydroxylamines, when the latter are anomeric, are shown to be a viable approach to a variety of hexahydrofuro[2,3-b]pyrrole 6-oxides.     

Cross-polarization dynamics in polycrystalline samples

We observe non-monotonic development of the ¹³C magnetization in polycrystalline samples of glycine, sucrose, and adamantine during cross-polarization. We demonstrate, by fitting the time dependence, that the development quantitatively results from dipolar oscillations. To fit the data quantitatively requires one to assume two types of spin-diffusion behavior.     

Atypical Film-Forming Behavior of Soluble Tetra-3-Nitro-Substituted Copper Phthalocyanine

Thin films of metal phthalocyanines (MPc) are known to exhibit excellent physical properties but poorly controlled morphologies. Therefore, the present work seeks to understand the film growth mechanism of a model compound for potentially usable MPc, specifically, copper tetra(3-nitro-5-tert-butyl)phthalocyanine (CuPc*). The Langmuir-Schaefer (LS) technique was applied to prepare a series of CuPc* films under different processing conditions. The film growth was examined by Brewster angle microscopy (BAM) on the water surface and small-angle X-ray scattering (SAXS) from the solid films. Neutron reflectometry (NR) measurements of the water uptake into the films and computer simulation of hydrated CuPc* were performed to substantiate an idea of colloidal MPc-water aggregates as nanoscale precursors of smooth solid films. This idea appears fruitful in terms of materials chemistry.     

"Seamless" graphene interconnects for the prospect of all-carbon spin-polarized field-effect transistors

Magnetism in graphene nanofragments arises from the spin polarization of the edge-states; consequently, as the material inexorably shrinks, magnetism will become a dominant feature whereas the bulk carrier mobility will be less relevant. We have carried out an ab initio study of the role of graphene-ultra-nanofragment magnetism on electronic transport. We present, as a proof-of-concept, a nanoscopic spin-polarized field-effect transistor (FET) with the channel and metallic contacts carved from a single graphene sheet. We demonstrate the selective tuning of conductance through electric-field control of the magnetic, rather than the charge, degrees of freedom of the channel, the latter typically employed in microscopic graphene FETs.     

Using Primary Source Projects to teach undergraduate mathematics content: analysis of instructor implementation and perceptions

ABSTRACT

This study investigates changes in instructor teaching tendencies, instructor’s perception of impact on student learning and dispositions, and methods of implementation of Primary Source Projects (PSPs). PSPs are curricular modules designed to teach core mathematical topics from primary historical sources rather than from standard textbooks. In essence, they are a form of inquiry-based learning that incorporates the history of mathematics through original source texts. We provide an overview of results from two semesters of implementation reports and surveys administered at the beginning and end of the semester by instructors who implemented PSPs in their undergraduate mathematics classes.