709 research outputs found
Conservative Inpatient Refeeding Yields Modest Outcomes in Adolescents with Anorexia Nervosa and Eating Disorder Not Otherwise Specified
Estimation and optimal designing under latent variable models for paired comparisons studies via a multiplicative algorithm
We consider:<BR/>
1. The problem of estimating the parameters of latent variable models such as the Bradley Terry or Thurstone Model by the method of maximum likelihood, given data from a paired comparisons experiment. The parameters of these models can be taken to be weights which are positive and sum to one;<BR/>
2. The problem of determining approximate locally optimal designs for good estimation of these parameters; i.e of determining optimal design weights which are also positive and sum to one
Patterning of ferroelectric nanodot arrays using a silicon nitride shadow mask
We grew well-ordered arrays of ferroelectric Pb (Zr0.2 Ti0.8) O3 (PZT) nanodots on a SrRu O3 SrTi O3 substrate by pulsed laser deposition. A silicon nitride shadow mask with ordered holes was used for patterning of the PZT arrays. Each dot has a height of ???15 nm and a diameter of ???120 nm with a similar dome shape over a large area. The ferroelectric properties of individual PZT dots were investigated by piezoresponse force microscopy. A single dot could be polarized individually and the polarized state remained unrelaxed to ???20 min.open232
Some improved estimators of finite population quantile using auxiliary information in sample surveys
Real Space Imaging of One-Dimensional Standing Waves: Direct Evidence for a Luttinger Liquid
Electronic standing waves with two different wavelengths were directly mapped
near one end of a single-wall carbon nanotube as a function of the tip position
and the sample bias voltage with highresolution position-resolved scanning
tunneling spectroscopy. The observed two standing waves caused by separate spin
and charge bosonic excitations are found to constitute direct evidence for a
Luttinger liquid. The increased group velocity of the charge excitation, the
power-law decay of their amplitudes away from the scattering boundary, and the
suppression of the density of states near the Fermi level were also directly
observed or calculated from the two different standing waves.Comment: 14 pages, 4 figures. The latest version in PDF format is available
from http://fy.chalmers.se/~eggert/papers/nanoLL.pd
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Observation of grain boundary segregation on an atomic scale in a Fe-0. 04% P alloy by atom-probe FIM
Grain boundaries introduced intentionally in a Fe-0.04% P alloy by cold-working were successfully observed using a field ion microscope (FIM), and the composition along a grain boundary was analyzed using a high-performance time-of-flight atom-probe. Phosphorus was found to segregate to the grain boundaries below 600/sup 0/C, in agreement with previous Auger electron spectroscopy studies. In addition to P, it was found that several other elements, such as Ti, O, C and Mn segregate to the grain boundaries at different annealing temperatures
Pseudospin rotation and valley mixing in electron scattering at graphene edges
In graphene, the pseudospin and the valley flavor arise as new types of
quantum degrees of freedom due to the honeycomb lattice comprising two
sublattices (A and B) and two inequivalent Dirac points (K and K') in the
Brillouin zone, respectively. Unique electronic properties of graphene result
in striking phenomena such as Klein tunnelling, Veselago lens, and
valley-polarized currents. Here, we investigate the roles of the pseudospin and
the valley in electron scattering at graphene edges and show that they are
strongly correlated with charge density modulations of short-wavelength
oscillations and slowly-decaying beat patterns. Theoretical analyses using
nearest-neighbor tight-binding methods and first-principles density-functional
theory calculations agree well with our experimental data from the scanning
tunneling microscopy. We believe that this study will lead to useful
application of graphene to "valleytronics" and "pseudospintronics".Comment: 13 pages, 4 figures, Supplementary Information available upon reques
Nanoarrays of tethered lipid bilayer rafts on poly(vinyl alcohol) hydrogels
Lipid rafts are cholesterol-and sphingolipid-rich domains that function as platforms for signal transduction and other cellular processes. Tethered lipid bilayers have been proposed as a promising model to describe the structure and function of cell membranes. We report a nano(submicro) array of tethered lipid bilayer raft membranes (tLBRMs) comprising a biosensing platform. Poly(vinyl alcohol) (PVA) hydrogel was directly patterned onto a solid substrate, using ultraviolet-nanoimprint lithography (UV-NIL), as an inert barrier to prevent biofouling. The robust structures of the nanopatterned PVA hydrogel were stable for up to three weeks in phosphate-buffered saline solution despite significant swelling (100% in height) by hydration. The PVA hydrogel strongly restricted the adhesion of vesicles, resulting in an array of highly selective hydrogel nanowells. tLBRMs were not formed by direct vesicle fusion, although raft vesicles containing poly(ethylene glycol) lipopolymer were selectively immobilized on gold substrates patterned with PVA hydrogel. The deposition of tLBRM nano(submicro) arrays was accomplished by a mixed, self-assembled monolayer-assisted vesicle fusion method. The monolayer was composed of a mixture of 2-mercaptoethanol and poly(ethylene glycol) lipopolymer, which promoted vesicle rupture. These results suggest that the fabrication of inert nanostructures and the site-selective modification of solid surfaces to induce vesicle rupture may be essential in the construction of tLBRM nano(submicro) arrays using stepwise self-assembly.This work was supported by Core Research for Evolutional Science and Technology (CREST) of Japan Science and Technology Agency (JST), and New Energy and Indstrial Technology
Development Organization (NEDO)
Direct observation of localized defect states in semiconductor nanotube junctions
Scanning tunneling microscopy of semiconductor-semiconductor carbon nanotube junctions with different band gaps was studied. Characteristic features of the wave functions at different energy levels were exhibited in the atomically resolved scanning tunneling microscopy. The experimental observations in terms of the pentagon-heptagon defects in the junction were interpreted.open888
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