Materials Literature
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A flat panel display prototype has been fabricated using gated carbon nanotubes as electron emission source. The gate structure is made by a self-aligned method. The pixels are turned “on” and “off” by controlling the gate electrode with a 50 V source. The operating properties of the display show much promise for furt…
The optical absorption spectra of Si(n)H(m) nanoclusters up to approximately 250 atoms are computed using a linear response theory within the time-dependent local density approximation (TDLDA). The TDLDA formalism allows the electronic screening and correlation effects, which determine exciton binding energies, to be…
We explore the electric-field effect of carbon nanotubes (NTs) in electrolytes. Due to the large gate capacitance, Fermi energy (EF) shifts of order ±1 V can be induced, enabling to tune NTs from p to n-type. Consequently, large resistance changes are measured. At zero gate voltage, the NTs are hole-doped in air with…
Recent low-temperature scanning tunneling experiments have challenged the generally accepted picture of buckled silicon dimers as the ground state reconstruction of the Si(100) surface. Together with the symmetric dimer model of the surface suggested by quantum chemistry calculations on small clusters, these findings…
A simple macroscopic continuum elasticity theory (CET) is used to calculate the structure relaxation of single-wall carbon nanotube (SWNT), an analytic formula is obtained. We also expand an atomic scale three-parameter empirical model [ T. Lenosky {\emph et al.} Nature 355, 333(1992)] in order to correctly describe t…
Vesicles made completely from diblock copolymers-polymersomes-can be stably prepared by a wide range of techniques common to liposomes. Processes such as film rehydration, sonication, and extrusion can generate many-micron giants as well as monodisperse, approximately 100 nm vesicles of PEO-PEE (polyethyleneoxide-poly…
We describe the structural and optical properties of II–VI oxide alloys, MgxZn1−xO and CdyZn1−yO, grown by pulsed-laser deposition. Single-phase alloyed films of (Mg,Zn)O and (Cd,Zn)O with c-axis orientations were epitaxially grown on sapphire (0001) substrates. The maximum magnesium and cadmium concentrations (x=0.33…
Collagen is the most abundant natural protein found in living systems. While there is a whole family of different collagen types, each differing in sequence, the properties that make this protein so attractive as the building blocks for medical devices, are reflected largely by the unique fibrillar structure of the mo…
The catalytic activity of LaFeO 3 perovskite for the gas-phase destruction of chlorinated compounds was investigated; 1,1,2-trichloroethylene in dry and moistened air was selected as the test compound. The catalyst showed good activity and satisfactory stability for prolonged time on stream (>200 h). Experimental data…
We have used X-ray reflectivity and Π-area isotherms to study Langmuir films of a series of second- and third-generation monodendrons with hydrophobic C 12 H 25 alkyl tails at the periphery and hydrophilic COOHCO 2 CH 3 or crown ether groups in the core. Both the limiting molecular areas and the layer thicknesss are c…
The electron-spin g shifts (magnetic moments μ S ) of X 2 Σ + (1π 4 3σ) radicals MX (±) with nine valence electrons are calculated at their equilibrium geometries, using second-order perturbation theory, a Hamiltonian based on Breit−Pauli theory, and correlated (MRCI) wave functions. Eighteen diatomics have been studi…
Taking advantage of the multifunctional characteristics of carbazole along with rational molecular design, a two-dimensional (2-D) carbazole chromophore was synthesized by a facile synthetic route. By doping of the chromophores into an organosoluble poly(ether imide), a series of guest−host NLO polymers were acquired.…
The fragile glass-forming liquid triphenyl phosphite (TPP) melts at 298 K, has a glass transition at about 186 K, and can undergo a first order transition to a metastable, solid, apparently amorphous phase (denoted the glacial phase) at about 230 K. Though apparently amorphous (on the basis of preliminary X-ray data),…
The release properties of the fluorescent probe pyrene, PYR, encapsulated in polyelectrolyte multilayer capsules were examined by fluorescence spectroscopy. PYR was encapsulated by the layer-by-layer deposition of oppositely charged polyelectrolytes onto PYR microcrystal templates, and its release was accomplished by…
An analytical method capable of identifying >30 chlorophyll-related compounds in plant extracts has been developed. The method employs liquid chromatography coupled to UV-vis, MS, and MS/MS detection. It can be applied without modification to analyze natural chlorophyll degradation products and other metalloporphyrine…
For the first time, a very general theoretical method is proposed to interpret the full electron paramagnetic resonance (EPR) spectra at multiple temperatures and frequencies in the important case of S-state metal ions complexed in liquid solution. This method is illustrated by a careful analysis of the measured spect…
We determined the surface structure of RuO 2 (100) formed on Ru(101̄0) by employing the techniques of low-energy electron diffraction (LEED) and density functional theory (DFT) calculations. The RuO 2 (100) film grows lattice-matched with its [010] direction along the [0001] direction of Ru(101̄0) (4.5% compressively…
The optical properties of colloidal semiconductor nanocrystals are found to be extremely sensitive to excess electrons. Electrons in the lowest quantum-confined state of the conduction band of CdSe and (CdSe)ZnS nanocrystals quench photoluminescence by several orders of magnitude, at the same time, leading to a strong…
Binuclear [FeIIFeIII(BMDP)(O2CPh)3](BF4) (1) was obtained by treating an acetonitrile solution of the fully reduced [FeIIFeII(BMDP)(O2CPh)(MeOH)1.5(H2O)0.5](BF4)2 with 5 equiv of benzoate and then exposing the mixture to oxygen. Examination of [FeIIFeIII(BMDP)(O2CPh)3](BF4) by X-ray crystallography reveals the localiz…
We report on our effective mass calculations for a particle confined in an ellipsoidal quantum dot. Upon using a curvilinear coordinates system, the single particle exact eigenvalues and eigenfunctions have been numerically calculated. Dielectric image effects have been properly taken into account. It is shown that on…