Materials Literature
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We demonstrate that a hexagonal two dimensional photonic crystal can act as an isotropic medium with an effective refractive index n_eff = -1, therefore capable of unrestricted superlensing. We study the superlensing by calculating the photonic band structure, and the propagation maps of the electromagnetic waves thro…
We present ab initio time-dependent-density-functional calculations and non-resonant inelastic x-ray scattering measurements of the dynamical structure factor of rutile TiO2. Our calculations are in good agreement with experiment and prove the presence of large crystal local-field effects below the Ti M-edge, which yi…
We use millimeter-wave radiation to manipulate the populations of the energy levels of a single crystal of molecular magnet ${\mathrm{Fe}}_{8}$. When continuous-wave radiation is in resonance with the transition from the ground state to the first excited state, the equilibrium magnetization exhibits a peak or dip whos…
The fractal structure of a white cauliflower is investigated by box-counting method of its cross-section. The capacity dimension of the cross-section is $1.88 \pm 0.02$ independent of directions. From the result, we predict that the capacity dimension of the cauliflower is about 2.8. The vertical cross-section of the…
We propose a new method for carrying out field-theoretic simulations of polymer systems under conditions of prescribed external stress, allowing for shape changes in the simulation box. A compact expression for the deviatoric stress tensor is derived in terms of the chain propagator, and is used to monitor changes in…
We report the effect of Al substitution on the Mn site of the bilayered half doped manganite ${\mathrm{La}}_{1}{\mathrm{Sr}}_{2}{\mathrm{Mn}}_{2}{\mathrm{O}}_{7}$. This substitution dilutes the magnetically active Mn-O-Mn network without introducing an appreciable distortion in the lattice, and ionic considerations le…
A novel approach is presented for the large-scale fabrication of ordered TiO 2 nanobowl arrays. The process starts with a self-assembled monolayer of polystyrene spheres, which is used as a template for atomic layer deposition of a TiO 2 layer. After ion-milling, toluene-etching, and annealing of the TiO 2 -coated sph…
Here we demonstrate, for the first time experimentally, a nanopipette action for metals using multiwalled carbon nanotubes. The process relies on electromigration forces, created at high electron current densities, enabling the transport of material inside the hollow core of carbon nanotubes. In this way nanoparticles…
Two polymer chains that occupy equal volumes when covalently linked together at one end self-assemble into an alternating lamellar morphology that has a characteristic period dictated by the molecular weight. When such copolymers are confined within alumina membranes that have cylindrical pores with diameters comparab…
We demonstrate an enhancement in the thermopower of PbTe nanostructures with grain sizes on the order of $30--50\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$, relative to bulk. The enhancement is similar in magnitude to that reported in the literature for $\mathrm{Pb}\mathrm{Te}∕\mathrm{Pb}{\mathrm{Se}}_{x}{\mathrm{Te}}_{1\…
The optimization of diamond films as valuable engineering materials for a wide variety of applications has required the development of robust methods for their characterization. Of the many methods used, Raman microscopy is perhaps the most valuable because it provides readily distinguishable signatures of each of the…
In Crystallization of Polymers, 2nd Edition, published in 2004, Leo Mandelkern provides a self-contained, comprehensive, and up-to-date treatment of polymer crystallization. Volume 2 of this edition provides an authoritative account of the kinetics and mechanisms of polymer crystallization, building from the equilibri…
Diatoms are unicellular algae with plastids acquired by secondary endosymbiosis. They are responsible for approximately 20% of global carbon fixation. We report the 34 million-base pair draft nuclear genome of the marine diatom Thalassiosira pseudonana and its 129 thousand-base pair plastid and 44 thousand-base pair m…
The novel concept of reverse flow operation with reactor side feeding is studied for selective oxidation of NH 3 to produce either N 2, N 2 O, or NO. During normal reverse flow operation, where the feeds are alternately introduced from either end of the reactor, the conversion is always lower when compared to steady s…
In situ time-resolved X-ray diffraction in combination with the Rietveld method was used to study the contraction/expansion behavior of a BaY faujasite zeolite during dehydration and NO 2 adsorption/desorption reactions. The adsorption of water and NO 2 molecules induced a significant contraction of the zeolite unit c…
A method for preparing carbon and SiC macroscopic beads using ion-exchange resins as a macrotemplate that determines the macroshape and the pore structure of the product materials is reported. First, silicates are ion-exchanged into the resins to prevent the resin from collapsing during subsequent carbonization and al…
We prepared disklike tris(4-alkylbutadiynylphenyl)-1,3,5-benzenetricarboxamide and tris[4-(4-alkyloxyphenyl)butadiynylphenyl]-1,3,5-benzenetricarboxamide, where three phenyl diacetylenic and diphenyl diacetylenic groups are connected to a benzene ring through amide linkages, respectively. The structures of self-assemb…
A systematic study on the structural properties and external morphologies of large-pore mesoporous organosilicas synthesized using triblock copolymer EO 20 PO 70 EO 20 as a template under low-acid conditions was carried out. By employing the characterization techniques of SAXS, FE-SEM, and physical adsorption of N 2 i…
We present the results of high-resolution photoluminescence and magneto-optical spectroscopy of selectively doped $\mathrm{Si}∕\mathrm{Si}:\mathrm{Er}$ nanolayer structures grown by sublimation molecular beam epitaxy method. We show that the annealing of such samples results in a preferential formation of a single typ…
We demonstrate that carbon nanotori constructed by either coalescing C 60 molecules along the 5-fold axis (incorporating pentagons and octagons) or by joining the ends of Haeckelite tubes (containing heptagons, hexagons, and pentagons) exhibit large magnetic moments when an external magnetic field is applied. In parti…