1,048 research outputs found
On mean convergence of Hermite–Fejér and Hermite interpolation for Erdős weights
AbstractWe investigate convergence of Hermite–Fejér and Hermite interpolation polynomials in Lp(0<p<∞) for Erdős weights
Necessary conditions for weighted mean convergence of Lagrange interpolation for exponential weights
AbstractGiven a continuous real-valued function f which vanishes outside a fixed finite interval, we establish necessary conditions for weighted mean convergence of Lagrange interpolation for a general class of even weights w which are of exponential decay on the real line or at the endpoints of (−1,1)
Dimensional Crossover driven by Magnetic Ordering in Optical Conductivity of Pr_{1/2}Sr_{1/2}MnO_3
We investigated optical properties of Pr_{0.5}Sr_{0.5}MnO_3, which has the
A-type antiferromagnetic ordering at a low temperature. We found that T-
dependence of spectral weight transfer shows a clear correlation with the
magnetic phase transition. In comparison with the optical conductivity results
of Nd_{0.5}Sr_{0.5}MnO_3, which has the CE-type antiferromagnetic charge
ordering, we showed that optical properties of Pr_{0.5}Sr_{0.5}MnO_3 near the
Neel temperature could be explained by a crossover from 3D to 2D metals.
Details of spectral weight changes are consistent with the polaron picture.Comment: 11 pages, 4 figures, submitted to PRL at June
Melting of Charge/Orbital Ordered States in NdSrMnO: Temperature and Magnetic Field Dependent Optical Studies
We investigated the temperature ( 15 290 K) and the magnetic
field ( 0 17 T) dependent optical conductivity spectra of a
charge/orbital ordered manganite, NdSrMnO. With variation
of and , large spectral weight changes were observed up to 4.0 eV. These
spectral weight changes could be explained using the polaron picture.
Interestingly, our results suggested that some local ordered state might remain
above the charge ordering temperature, and that the charge/orbital melted state
at a high magnetic field (i.e. at 17 T and 4.2 K) should be a three
dimensional ferromagnetic metal. We also investigated the first order phase
transition from the charge/orbital ordered state to ferromagnetic metallic
state using the - and % -dependent dielectric constants . In
the charge/orbital ordered insulating state, was positive and
. With increasing and , was
increased up to the insulator-metal phase boundaries. And then,
abruptly changed into negative and , which was
consistent with typical responses of a metal. Through the analysis of using an effective medium approximation, we found that the melting
of charge/orbital ordered states should occur through the percolation of
ferromagnetic metal domains.Comment: submitted to Phys. Rev.
Micro Membrane Filters for Passive Plasma Extraction From Whole Human Blood Using Silicon Nitride-based Microfilters and Plama Collection Using Agarose Gels
AbstractThe novelty of this study resides in the fabrication of a passive, operating on capillary force, penetration-flow microfluidic device for plasma separation, based on both silicon nitride combination (SiN-SiO-SiN)-based microfilters and agarose gels, and its characterization for plasma separation from whole human blood. The fabrication processes are compatible with IC process protocols, with merits of mass productions and precise size control. The fabrication process for silicon nitride membrane was reported at Lab Chip [1], and quantification its applications to affinity-based protein separation on the silicon nitride was reported at MicroTAS’07 [2]. Our method differs from that of group Yobas [3] in the specific separation method and materials, and of group Pizziconi [4] in the geometry of the filter, and fluidic components with the structure
Optical Investigations of Charge Gap in Orbital Ordered La1/2Sr3/2MnO4
Temperature and polarization dependent electronic structure of La1/2Sr3/2MnO4
were investigated by optical conductivity analyses. With decreasing
temperature, for E//ab, a broad mid-infrared (MIR) peak of La1/2Sr3/2MnO4
becomes narrower and moves to the higher frequency, while that of
Nd1/2Sr3/2MnO4 nearly temperature independent. We showed that the MIR peak in
La1/2Sr3/2MnO4 originates from orbital ordering associated with CE-type
magnetic ordering and that the Jahn-Teller distortion has a significant
influence on the width and the position of the MIR peak.Comment: 10 pages, 4 figure
Optical Evidence of Multiphase Coexistence in Single Crystalline (La,Pr,Ca)MnO3
We investigated temperature (T)- and magnetic field-dependent optical
conductivity spectra (\s\w) of a La_5/8-yPr_yCa_3/8MnO_3 (y~0.35) single
crystal, showing intriguing phase coexistence at low T. At T_C < T < T_CO, a
dominant charge-ordered phase produces a large optical gap energy of ~0.4 eV.
At T < T_C, at least two absorption bands newly emerge below 0.4 eV. Analyses
of (\s\w) indicate that the new bands should be attributed to a ferromagnetic
metallic and a charge-disordered phase that coexist with the charge-ordered
phase. This optical study clearly shows that La_5/8-yPrCa_3/8MnO_3 (y~0.35) is
composed of multiphases that might have different lattice strains.Comment: A single file with 9 figures embedded, to appear in Phys. Rev.
1-GHz all-optical flip-flop operation of conventional cylindrical-shaped single-mode VCSELs under low-power optical injection.
Room temperature ferromagnetism in chemically synthesized ZnO rods
We report structural and magnetic properties of pure ZnO rods using X-ray
diffraction (XRD), magnetization hysteresis (M-H) loop and near edge x-ray fine
structure spectroscopy (NEXAFS) study at O K edge. Sample of ZnO was prepared
by co-precipitation method. XRD and selective area electron diffraction
measurements infer that ZnO rods exhibit a single phase polycrystalline nature
with wurtzite lattice. Field emission transmission electron microscopy, field
emission scanning electron microscopy micrographs infers that ZnO have rod type
microstructures with dimension 200 nm in diameter and 550 nm in length. M-H
loop studies performed at room temperature display room temperature
ferromagnetism in ZnO rods. NEXAFS study reflects absence of the oxygen
vacancies in pure ZnO rods.Comment: 8 Pages, 3 Figure
Outcome of allogeneic hematopoietic stem cell transplantation after adding high-dose cytarabine to the conventional Cy/TBI conditioning regimen for the treatment of Philadelphia-chromosome-positive acute lymphoblastic leukemia
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