Search

We report a reproducible procedure to fabricate high quality steps and step-edge junctions on SrTiO3(STO) substrate. The dynamic process of Ion Milling(IM) was simulated in theory, there exists a maximum slope angle for the steps prepared from ion milling. For 500eV Ar+ bombarding STO system, the angle is about 73°. High quality steps can be acquired with new technique procedure. Voltage modulation is about 10μV for a typical DC-SQUIDs fabricated on this type of substrate.

Precursor-route pentacene thin film transistor characteristics are presented. The device temperature dependance is reported and the results discussed in terms of a distribution of mobilities. Voltage modulation spectroscopy is also reported and features discussed.

We have fabricated YBa2Cu3O7−δ edge junction dc SQUIDs working at 77 K with 5∼10 nm thick PrBa2Cu3O7−δ layer as the junction barrier. The SQUIDs were made by the pulsed laser film deposition technique and the photolithographic patterning with Ar+ milling. The junctions made showed resistively-shunted-junction (RSJ) characteristics near Tc and the SQUID voltage modulation in response to magnetic fields was on the order of μ V and was observed up to 80 K.

The developed address-vlotage-modulation drive generates pre-discharge in an ac-PDP (plasma display panel) by applying a rising address-pulse voltage during the sustain-pulse-open period. This pre-discharge increases the panel luminous efficiency by approximately 30%. This increase in luminous efficiency is a result of decreases in effective discharge voltage and electron temperature.

An active matrix EL VGA display is reported with full grayscale using temporal voltage modulation of the phosphor. The exceptional brightness and dynamic range of the ZnS:Mn EL phosphor permits a new gray scale scheme. Digital gamma correction and an extended range of levels achieve 128 to 256 monotonic shades.

The performance of DC-SQUIDS with inductively and resistively shunted inductances is studied theoretically and experimentally and compared to the performance of a standard (unshunted) SQUID. By shunting the inductance the voltage modulation depth remains unaffected for large β. The consequences for the flux-voltage transfer and the noise performance are discussed.

Josephson junctions and DC SQUIDs were fabricated in an edge-geometry superconductor/normal-metal/superconductor configuration using Ag-doped YBa2Cu3O7-x electrodes and a PrBa2Cu3O7-x N-layer. A differential voltage modulation of over 150 µV/Φ0 at 75 K was achieved. The flux noise was 30~40 µΦ0Hz-1/2 measured with DC bias at a frequency of 1 Hz.

An artificial step-edge junction for developing the high T c weak links is presented. The step-edge junction is fabricated by using the step edge of the double layer of the epitaxial YBaCuO films. The dc superconducting quantum interference device (SQUID) made of the junction shows a clear voltage-vs-flux (V-Φ) relation up to T=81.3 K. The voltage modulation depth ΔV of the V-Φ relation is ΔV=1.6 µV at T=77 K. A preliminary experiment shows that the magnetic-flux noise of the SQUID at T=77 K is, at most, Φ n =4.4×10-4Φ0/√Hz at f=10 Hz. These results show the promising properties of the step-edge junction for the weak link of high T c superconductors.

We have investigated the voltage tuning of b‐axis CdS phonon masers. Voltage modulation is found to be a fairly complex phenomenon involving amplitude as well as frequency modulation of the phonon maser output. Near threshold, the frequency modulation is typically of the order of 10 kHz/V. The response is flat up to frequencies of the order of the reciprocal of the acoustic transit time. At the higher driving voltages, the tuning is reduced. The device appears promising as a FM communications transmitter.

The existence of finite small-signal drain-body and source-body conductances g_{r}(T) associated with drain and source to body diffusion leakage currents in MOSFET's is reported. These currents and therefore these conductances increase as n\min{i}\max{2}(T) with increasing temperature. For devices of geometries commonly encountered in analog MOS integrated circuits, these conductances typically become comparable in magnitude to the conventional output (g d ) and body effect (g mb ) conductances between 200° and 250°C. The origin of these conductances is traced to the voltage modulation of the effective areas of the junctions under consideration. This modulation occurs through the reverse-bias voltage (V r ) induced modulation of the depletion region thicknesses w(V_{r}, T) of the junctions. Expressing leakage currents as I(V_{r}, T) = J(V_{r}, T)' \cdot A(V_{r}, T) where J(V_{r}>, T) and A (V_{r}, T) are voltage- and temperature-dependent current density and junction area, respectively, we find that whereas with generation-recombination leakage currents (dominating in the range 25° to 150°) the g_{r}(T) result from the voltage dependence of J(V_{r}, T) ; it is the area A(V_{r}, T) whose modulation by voltage dominates that of J(V_{r}, T) in the case of diffusion leakage currents (T > 150° C). A modified small-signal MOSFET model is proposed which includes the aforementioned conductances g_{r}(T) , and consequences of these for high-temperature analog MOS IC design are highlighted. Experimental data supporting the reported interpretation are presented.

Les intensites relatives des raies d'emission des elements pulverises sont augmentees par la methode de modulation de la tension

The effect of sinusoidal current on the corrosion of mild steel in aqueous solution has been examined with an alternating voltage (AV) modulation method. It was found that AV shifted the corrosion potential toward the negative direction, increased dissolution current density in the active region, and destroyed the passivity of mild steel at the passive potentials. The effect of AV was simulated numerically with a charge‐transfer reaction model, and the calculated polarization curves showed the characteristics similar to those of the experimental curves.

Details axe given of the work accomplished at the Naval Air Development Center (NADEVCEN) to develop an adequate definition of voltage modulation in aircraft constant-frequency electric systems. Instrumentation was developed for the laboratory phase of the investigation. From the laboratory data and other commercial correlating data, a new and more complete definition of voltage modulation was developed. This definition is also recommended for integration into other military specifications involving aircraft a-c electric generating and regulating equipment.

Publisher Summary This chapter discusses the application of noise measurements to the study of the ionic channels that are responsible for the voltage modulation of the conductance of axonal membranes. The chapter presents the basic concepts of fluctuation analysis and the physical basis of membrane noise. Membrane noise in general contains several components that are not simply related to the discrete nature of ionic channels. An understanding of all possible noise sources is, therefore, essential for the unambiguous interpretation of membrane noise in terms of channel fluctuations. In addition, the channel noise is analyzed based upon the fundamental assumption that ionic channels have a relatively small number of states that are kinetically distinguishable within the time resolution of the measuring apparatus. The chapter emphasizes on the application of patch recording techniques to the study of ionic channels in the squid axon membrane. The patch recordings have provided the most convincing definite proof of the notion that guided the interpretation of noise data.

The sino atrial pacemaker dominates subsidiary pacemakers through the process of overdrive suppression. Subsidiary pacemakers that demonstrate spontaneous diastolic depolarization are located in specialized atrial and ventricular fibers. Diastolic depolarization is normally absent in ordinary atrial and ventricular fibers, although under certain experimental conditions, considered by Surawicz [l], these fibers may develop diastolic depolarization and spontaneous automaticity. The purpose of this chapter is to review the mechanisms responsible for diastolic depolarization and spontaneous automaticity in cardiac Purkinje fibers, with particular emphasis on the effects that pharmacologic agents exert on automaticity that occur at high and low levels of transmembrane potential.

SRAM cell stability analysis is typically based on Static Noise Margin (SNM) evaluation when in hold mode, although memory errors may also occur during read operations. Given that SNM varies with each cell operation, a thorough analysis of SNM in read mode is required. In this paper we investigate the SNM of OAM cells during write operations. The Word-Line Voltage modulation is proposed as an alternative to improve cell stability when in this mode. We show that it is possible to improve 8T OAM cells stability during write operations while reducing current leakage, as opposed to present methods that improve cell stability at the cost of leakage increase.

The paper discusses the response of flickermeters to interharmonic voltage pollution from theoretical and experimental points of view. Light flicker can be caused by interharmonics because these components are able to introduce fluctuations both in rms and peak value of supply voltage. The IEC standard flickermeter was deigned, for historical reasons, only with reference to amplitude voltage modulation that is the first source of light flicker identified. Nevertheless, the instrument was expected to properly work and measure also the effects of interharmonics. The paper presents a test system able to perform the advanced calibration and performance verification of flickermeter also with reference to interharmonic pollution. The experimental results obtained testing a commercial instrument are shown and discussed.

By modulating the RF voltage at near twice the synchrotron frequency we are able to modulate the longitudinal bunch shape. We show experimentally that this can be done while preserving the longitudinal emittance when the RF voltage modulation is turned on adiabatically. Experimental measurements are presented along with theoretical predictions.

Describes an apparatus and a heterojunction that can be used under 2.6 eV, for any temperature; these were used for measurements of electroreflection by a surface barrier. Delta R/R of 10-6 was measured with a voltage modulation of 0.2 mV. Quantitative measurements showed that there were few surface states and that the radial electric field was homogeneous. A magneto-electroreflection spectrum of Ge shows an example of use at low temperature.

A low cost photometer is described which is intended to be used in conjunction with voltage modulation of the LEED suppressor grid.

There have been numerous reports on the practical limitations of conventional p+-n-n+ avalanche diodes. These reports conclude that large-signal power saturation occurs at about 35% voltage modulation in silicon and at a somewhat higher level in gallium arsenide. This power saturation can, to a large extent, be attributed to the losses incurred in the diode, owing to the effective series resistance of unswept epitaxial material, an effect that necessarily occurs at large voltage swings. This depletion-layer modulation also gives rise to detrimental parametric effects under large-signal conditions. The letter briefly reviews the prime causes of this power saturation, and explains how voltage modulation in excess of 75% may be obtained, without any depletion-layer modulation, by using a 4-layer structure. Conversion efficiencies exceeding 55% can be obtained, while retaining the advantages of the p+-n-n+ structure.