High Electrical Activity Research Articles

Use of a scanning cw Kr laser to obtain diffusion-free annealing of B-implanted silicon

The use of a continuous scanned Kr ion laser as a tool for annealing of boron-implanted silicon is described. Conditions were found that produce high electrical activity and crystallinity of the implanted layer without redistribution of the boron from the as-implanted profile.

The effect of argon implantation on the conductivity of boron implanted silicon

Silicon wafers have been implanted with boron (3 × 10 14 or 1 × 10 15 ions cm −2) and with argon (up to 1 × 10 15 ions cm −2). The energies were chosen to approximately superimpose the two impurity distributions. After the boron and argon implantations the sheet resistance of each wafer was measured following annealing in nitrogen at temperatures in the range 400–1050°C. The highest dose argon implantation produced an increase in sheet resistance which persisted throughout the entire temperature range. Lower argon doses produced a reduction in sheet resistance for anneal temperatures between 550 and 800°C. The magnitude of the reduction is a function of the boron and argon doses and of the anneal temperatures. The greatest reduction, observed after a 600°C anneal, was by a factor of 5.8. Above 800°C the low dose argon did not affect the sheet resistance. The observed reduction in sheet resistance is expected to lead to an improvement in metal to p-type silicon contacts. A particular application is in the contacts to resistors in fast bipolar logic circuits. As high electrical activity can be obtained at moderate annealing temperatures with combined boron and argon implantations, these implantations can be carried out at a late stage in an integrated circuit process schedule without the danger of additional movement of existing junctions.

Affective behavior changes in cats following operant conditioning of amygdaloid EEG activity

Enhanced agonistic behaviors were observed in cats following training, using biofeedback techniques, which increased the EEG activity recorded from the lateral amygdaloid nucleus. The animals' affective behavior returned to pretraining baseline levels after the elevated EEG activity had been extinguished. Results are discussed in the context of the significance of high frequency electrical activity of the brain.

Flow of a supersonic electrogasdynamic stream, with formation of an electroconducting gaseous shock layer

Surfaces of strong discontinuity in electrogasdynamics were considered in [1, 2]. An investigation was done for the case when a gas has the properties of a unipolar charged medium on both sides of a surface of discontinuity. However, with sufficiently high supersonic gas flow over bodies the gas becomes electroconducting and acquires the properties of a low-temperature plasma in the compressed layer between the shock wave and the body, because of the temperature increase. Therefore, there is great interest in investigating type S* Shockwaves dividing a unipolar charged medium and a low-temperature plasma. The S* waves separating the uncharged medium and a gas with high electrical activity in the presence of an electrical field were studied in [3]. Below we examine the general properties of S* waves (physicalmodel, relations at the wave, conditions for development, shock adiabats, and polars). We formulate the problem of flow of a supersonic electrogasdynamic stream over bodies, with formation of S* waves. A perturbation method is proposed for solution of the problem, using a small parameter to describe electrogasdynamic interaction. By way of example a complete solution for flow over a wedge is constructed.

Impedance and spontaneous electrical activity as a localizing method in percutaneous spinal surgery.

Simultaneous recording of impedance and spontaneous electrical activity of the spinal cord was accomplished by use of a roving electrode. The method for this double monitoring in cats and in human surgery is described. The impedance method revealed a significant and well-delineated difference between the gray and white matter of the spinal cord which can be seen clearly on the recording. Well-localized high electrical activity was observed in the anterior horn.

Lattice location and dopant behavior of group II and VI elements implanted in silicon

Abstract Outdiffusion, lattice location and electrical behavior of Zn, Cd, Hg and Se, Te implanted into silicon at 50 keV were investigated by backscattering and channeling effect of 1 MeV He+ ions and by Hall effect and sheet resistivity measurements. All the species exhibited outdiffusion with thermal processing. A significant fraction of Zn, Cd and Hg, when implanted into a substrate of 350°C, occupied regular interstitial lattice sites, while 50–60 per cent of the Se and Te atoms were on substitutional lattice sites. Selenium implanted at room temperature and mercury implanted into a substrate of 350°C exhibited depth dependent lattice location. The implanted layers showed n-type behavior: the maximum value of number of carriers/cm2 was less than the number of implanted ions/cm2 in all cases. The highest electrical activity was observed for Se corresponding to 25 per cent of the substitutional component.

Regional features of background electrical activity and of direct cortical response by the intact or neuronally isolated cortex

Background electrical activity and thresholds for the appearance of direct cortical responses (DCR) were studied in acute and chronic experiments on cats in some gyri of the intact and neuronally isolated cortex (the whole cortex was subjected to neuronal isolation [10]). It was determined that in intact animals the suprasylvian gyrus, particularly its central part, differs by its higher electrical activity and lower DCR thresholds from the ectosylvian gyrus. These differences are retained after neuronal isolation of the cortex from the subcortical structures. Hence the differences found in the neurophysiologic characteristics of the gyri under study reflect specific properties and are not mediated by subcortical neural effects.

Incorporation of radioactive methionine into giant neurons of the mollusk

In the buccal ganglia of the freshwater mollusk Planorbis co~'neus protein synthesis takes place most intensively in thebodies of nerve cells. Protein synthesis in giant neurons takes place with equal intensity both in cytoplasm and nucleus, 60% of the total mass of sulfur-containin g protein being produced by the cytoplasm. Protein leaves the neuron body principally along the axon. It migrates along the axon at a rate of about 0.2mm/day. Giant neurons of the buceal ganglia are characterized by very high electrical activity, giving way periodically (at intervals of 3-5 sec) to deep and prolonged (about 1 see) inhibition. This type of periodic unit activity continues substantially unchanged for up to 20 hr if the surrounding isotonic solution is constantly renewed.

Electroencephalographic changes after unilateral partial extirpation of cerebellar nuclei

Unilateral partial extirpation of the cerebellar nuclei produces asymmetry of electrical activity in all investigated parts of the central nervous system (telencephalon, diencephalon, mesencephalon, and cerebellum). The manifestations of this asymmetry are given below. 1. In cortical areas 1–8 and 12, and also in the caudate nucleus, contralateral to the lesion, the amplitude of potentials is decreased and their frequency increased. In the cortex of the homolateral hemisphere, an increase in amplitude of the potentials is observed. This dissociation of frequencies and amplitudes in the right and left hemispheres is manifestly maintained or, conversely, strengthened during generalized inhibition caused by injection of thiopental sodium (25 mg/kg) and during diffuse activation following administration of armin (0.5–0.25 mg/kg) or arecoline (0.3 mg/kg). Total disappearance of spindles or a marked weakening of spindle-like rhythms is observed in the cortex and basal ganglia of the contralateral hemisphere. 2. In the medial thalamic nuclei and mesencephalic reticular formation the amplitude of high-frequency (beta- and gamma-) waves on the side of the lesion is increased by comparison with their amplitude on the intact side. 3. Against the background of diffuse armin activation, the higher electrical activity in the neocortex of the contralateral cerebellar hemisphere is clearly visible.

Eletrical Properties of Glasses in the System PbO‐Al2O3‐B2O3‐SiO2

Glasses in the system Pb0–Al2O3‐B2O3‐SiO2 are chemically stable over a wide composition range and have very desirable electrical characteristics such as high electrical resistivities and activation energies for conduction. Variations in these electrical properties were studied as a function of composition changes within the system, the object being to identify the role of the constituent oxides in achieving the highest activation energy and resistivity values consistent with moderate preparation temperatures. Measurements were made in the temperature range 25° to 400°C on carefully prepared glass disks in which the individual oxide components or different oxide ratios such as PbO/SiO2, Al2O3/SiO2, and BsO3/SiO1 were systematically varied. The activation energy and resistivity values obtained ranged from 1.2 to 1.6 ev and 10° to 1014 ohm‐cm, with dielectric constants ranging from 9 to 19 and densities from 4.30 to 4.50 g/cmY. Indications were that, for the composition range studied, the behavior manifested was basically that of the binary PbO‐SO2 glass with additions of Al2O3 or B2O3, even in small concentrations, sharply increasing the activation energy for conduction while lowering the density.

Physiological peculiarities of thermoregulation in bats

In bats, intensive “warming” of the body after hibernation is associated with a high electric activity of the skeletal muscles during complete rest of the animal (thermoregulation tone). It is concluded that the “thermoregulation tone” is an important source of sharply increased thermoproduction during this period.