1,829 research outputs found
New chalcogenide glasses in the GeSe2-Ga2Se3-In2Se3 and GeSe2-Ga2Se3-PbSe domains
International audienceTwo new chalcogenide glassy domains were explored by substituting Ga for In or Pb in compositions from the GeSe2-Ga2Se3 tie line in the Ge-Ga-Se ternary diagram. The thermal, optical and mechanical properties of these glasses were determined and the effect of the substitutions on these properties was assessed. It is shown that addition of lead tends to destabilize the glasses while the addition of indium tends to stabilize them. Both elements induce a systematic increase in the onset of transmission values and in the densities when substituted to gallium. The glasses synthesized represent good potential candidates for the production of glass-ceramics with photovoltaic or nonlinear properties
Analysis of the dynamic changes in the soft palate and uvula in obstructive sleep apnea-hypopnea using ultrafast magnetic resonance imaging
Apnea and the respiratory cycle are dynamic processes in obstructive sleep apnea-hypopnea (OSAH), which occur only during sleep. Our study aimed to observe the dynamic changes in the soft palate and the uvula during wakefulness and sleep using ultrafast magnetic resonance imaging (UMRI) to provide reference data for the pathogenesis and treatment of OSAH. The dynamic changes in the soft palate and uvular tip of 15 male patients (average age: 50.43 ± 9.82 years) with OSAH were evaluated using UMRI of the upper airway while asleep and awake after 1 night of sleep deprivation. A series of midline sagittal images of the upper airway were obtained. The distance from the center of the soft palate to the x-axis (an extended line from the anterior nasal spine to the posterior nasal spine), from the uvular tip to the x-axis, from the center of the soft palate to the y-axis (a perpendicular line from the center of the pituitary to the x-axis), and from the uvular tip to the y-axis (designated as PX, UX, PY, and UY, respectively) were measured during sleep and wakefulness. The minimum PX, PY, UX, and UY were shorter during sleep than during wakefulness, whereas the maxima were longer during sleep (P < 0.01), the differences between the maximum and minimum PX, PY, UX, and UY were larger during sleep (P < 0.01). The upward, downward, forward, and backward ranges of movement of the soft palate and the uvular tip were larger during sleep in OSAH patients. This increased compliance may trigger each airway obstructive event
Finite Domain Anomalous Spreading Consistent with First and Second Law
After reviewing the problematic behavior of some previously suggested finite
interval spatial operators of the symmetric Riesz type, we create a wish list
leading toward a new spatial operator suitable to use in the space-time
fractional differential equation of anomalous diffusion when the transport of
material is strictly restricted to a bounded domain. Based on recent studies of
wall effects, we introduce a new definition of the spatial operator and
illustrate its favorable characteristics. We provide two numerical methods to
solve the modified space-time fractional differential equation and show
particular results illustrating compliance to our established list of
requirements, most important to the conservation principle and the second law
of thermodynamics.Comment: 14 figure
XFEM Simulation of Pore-Induced Fracture of a Heterogeneous Concrete Beam in Three-Point Bending
The extended finite element method with the linear softening law is employed to simulate poreinduced crack initiation and propagation in heterogeneous plain concrete beams in three-point bending. A series of numerical simulations was performed and experimentally validated. The crack was found to always initiate at the beam bottom in the point nearest to the pore, propagating through it. When the pore has a larger offset from the beam midspan, the beam displays higher fracture resistance and energy dissipation spent for fracture. With an increase in a distance from the beam bottom, the ultimate load also increases, but the energy dissipation slightly varies. The pore sizes have a little effect on the fracture resistance of the concrete beam.Моделирование вызванных пористостью зарождения и распространения трещины в бетонных балках неоднородной структуры при трехточечном изгибе выполнено с помощью расширенного метода конечных элементов и закона линейного разупрочнения. Проведен ряд операций численного моделирования, проверенных экспериментально. Установлено, что трещина всегда зарождается на нижней грани балки в точке, ближайшей к поре, прорастая сквозь нее. Если пора в большей степени смещена относительно среднего пролета балки, последняя проявляет более высокое сопротивление разрушению и диссипацию энергии, затрачиваемой на разрушение. По мере увеличения расстояния от поры до нижней грани балки допустимая нагрузка также возрастает, а диссипация энергии несколько изменяется. Показано, что размеры пор оказывают незначительное влияние на сопротивление бетонной балки разрушению
Charge ordering in charge-compensated by oxonium ions
Charge ordering behavior is observed in the crystal prepared through the
immersion of the crystal in distilled water. Discovery of the
charge ordering in the crystal with Na content less than 0.5 indicates that the
immersion in water brings about the reduction of the
. The formal valence of Co changes from +3.59 estimated from
the
Na content to +3.5, the same as that in . The charge
compensation is confirmed to arise from the intercalation of the oxonium ions
as occurred in the superconducting sodium cobalt oxide
bilayer-hydrate.\cite{takada1}
The charge ordering is the same as that observed in . It
suggests that the Co valence of +3.5 is necessary for the charge ordering.Comment: 5 pages, 4 figure
Faithful remote state preparation using finite classical bits and a non-maximally entangled state
We present many ensembles of states that can be remotely prepared by using
minimum classical bits from Alice to Bob and their previously shared entangled
state and prove that we have found all the ensembles in two-dimensional case.
Furthermore we show that any pure quantum state can be remotely and faithfully
prepared by using finite classical bits from Alice to Bob and their previously
shared nonmaximally entangled state though no faithful quantum teleportation
protocols can be achieved by using a nonmaximally entangled state.Comment: 6 page
- …