11,573 research outputs found
Reduced 30% scanning time 3D multiplexer integrated circuit applied to large array format 20KHZ frequency inkjet print heads
Enhancement of the number and array density of nozzles within an inkjet head
chip is one of the keys to raise the printing speed and printing resolutions.
However, traditional 2D architecture of driving circuits can not meet the
requirement for high scanning speed and low data accessing points when nozzle
numbers greater than 1000. This paper proposes a novel architecture of
high-selection-speed three-dimensional data registration for inkjet
applications. With the configuration of three-dimensional data registration,
the number of data accessing points as well as the scanning lines can be
greatly reduced for large array inkjet printheads with nozzles numbering more
than 1000. This IC (Integrated Circuit) architecture involves three-dimensional
multiplexing with the provision of a gating transistor for each ink firing
resistor, where ink firing resistors are triggered only by the selection of
their associated gating transistors. Three signals: selection (S), address (A),
and power supply (P), are employed together to activate a nozzle for droplet
ejection. The smart printhead controller has been designed by a 0.35 um CMOS
process with a total circuit area, 2500 x 500 microm2, which is 80% of the
cirucuit area by 2D configuration for 1000 nozzles. Experiment results
demonstrate the functionality of the fabricated IC in operation, signal
transmission and a potential to control more than 1000 nozzles with only 31
data access points and reduced 30% scanning time.Comment: Submitted on behalf of EDA Publishing Association
(http://irevues.inist.fr/EDA-Publishing
Neutron spin-echo study of the critical dynamics of spin-5/2 antiferromagnets in two and three dimensions
We report a neutron spin-echo study of the critical dynamics in the
antiferromagnets MnF and RbMnF with three-dimensional (3D) and
two-dimensional (2D) spin systems, respectively, in zero external field. Both
compounds are Heisenberg antiferromagnets with a small uniaxial anisotropy
resulting from dipolar spin-spin interactions, which leads to a crossover in
the critical dynamics close to the N\'eel temperature, . By taking
advantage of the energy resolution of the spin-echo
spectrometer, we have determined the dynamical critical exponents for both
longitudinal and transverse fluctuations. In MnF, both the characteristic
temperature for crossover from 3D Heisenberg to 3D Ising behavior and the
exponents in both regimes are consistent with predictions from the
dynamical scaling theory. The amplitude ratio of longitudinal and transverse
fluctuations also agrees with predictions. In RbMnF, the critical
dynamics crosses over from the expected 2D Heisenberg behavior for
to a scaling regime with exponent , which has not been predicted
by theory and may indicate the influence of long-range dipolar interactions
Laser pulse annealing of ion-implanted GaAs
GaAs single-crystals wafers are implanted at room temperature with 400-keV Te + ions to a dose of 1×10^15 cm^–2 to form an amorphous surface layer. The recrystallization of this layer is investigated by backscattering spectrometry and transmission electron microscopy after transient annealing by Q-switched ruby laser irradiation. An energy density threshold of about 1.0 J/cm^2 exists above which the layer regrows epitaxially. Below the threshold the layer is polycrystalline; the grain size increases as the energy density approaches threshold. The results are analogous to those reported for the elemental semiconductors, Si and Ge. The threshold value observed is in good agreement with that predicted by the simple model successfully applied previously to Si and Ge
Translational Invariance and the Anisotropy of the Cosmic Microwave Background
Primordial quantum fluctuations produced by inflation are conventionally
assumed to be statistically homogeneous, a consequence of translational
invariance. In this paper we quantify the potentially observable effects of a
small violation of translational invariance during inflation, as characterized
by the presence of a preferred point, line, or plane. We explore the imprint
such a violation would leave on the cosmic microwave background anisotropy, and
provide explicit formulas for the expected amplitudes of
the spherical-harmonic coefficients.Comment: Notation improve
Heteroepitaxy of deposited amorphous layer by pulsed electron-beam irradiation
We demonstrate that a single short pulse of electron irradiation of appropriate energy is capable of recrystallizing epitaxially an amorphous Ge layer deposited on either or Si single-crystal substrate. The primary defects observed in the case were dislocations, whereas stacking faults were observed in samples
Epitaxial growth of deposited amorphous layer by laser annealing
We demonstrate that a single short pulse of laser irradiation of appropriate energy is capable of recrystallizing in open air an amorphous Si layer deposited on a (100) single-crystal substrate into an epitaxial layer. The laser pulse annealing technique is shown to overcome the interfacial oxide obstacle which usually leads to polycrystalline formation in normal thermal annealing
Ultrafast all-optical switching via coherent modulation of metamaterial absorption
We report on the demonstration of a femtosecond all-optical modulator
providing, without nonlinearity and therefore at arbitrarily low intensity,
ultrafast light-by-light control. The device engages the coherent interaction
of optical waves on a metamaterial nanostructure only 30 nm thick to
efficiently control absorption of near-infrared (750-1040 nm) femtosecond
pulses, providing switching contrast ratios approaching 3:1 with a modulation
bandwidth in excess of 2 THz. The functional paradigm illustrated here opens
the path to a family of novel meta-devices for ultra-fast optical data
processing in coherent networks.Comment: 5 pages, 4 figure
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