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1.
J Phys Condens Matter ; 30(25): 254002, 2018 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-29708499

RESUMO

We report the capability to simulate in a quantum-mechanical atomistic fashion record-large nanowire devices, featuring several hundred to millions of atoms and a diameter up to 18.2 nm. We have employed a tight-binding mode-space NEGF technique demonstrating by far the fastest (up to 10 000 × faster) but accurate (error < 1%) atomistic simulations to date. Such technique and capability opens new avenues to explore and understand the physics of nanoscale and mesoscopic devices dominated by quantum effects. In particular, our method addresses in an unprecedented way the technologically-relevant case of band-to-band tunneling (BTBT) in III-V nanowire broken-gap heterojunction tunnel-FETs (HTFETs). We demonstrate an accurate match of simulated BTBT currents to experimental measurements in a 12 nm diameter InAs NW and in an InAs/GaSb Esaki tunneling diode. We apply our TB MS simulations and report the first in-depth atomistic study of the scaling potential of III-V GAA nanowire HTFETs including the effect of electron-phonon scattering and discrete dopant impurity band tails, quantifying the benefits of this technology for low-power low-voltage CMOS applications.

2.
Yi Chuan Xue Bao ; 27(4): 317-24, 2000.
Artigo em Chinês | MEDLINE | ID: mdl-11147350

RESUMO

Fluorescence in situ hybridization was applied to the meiotic analysis and chromosome pairing in the pollen mother cells of hybrids of Triticum-Haynaldia. The results indicated that most (90.5%-93.2%) of the PMCs of two Triticum-Haynaldia hybrids contained two univalents involving one Haynaldia chromosome at metaphase I, and only 1 of 320 PMCs with homologous pairing between one wheat chromosome and one Haynaldia chromosome was observed in the hybrid of Guinong 22 x common wheat Chinese Spring, the frequency was 0.3%. The frequencies of the PMCs with mis-dividing chromosome ranged from 32.7% to 37.5% at anaphase I and from 20.5% to 24.4% at anaphase II in the hybrids between Triticum-Haynaldia. The frequency of Haynaldia chromatin translocating into Triticum chromosome was about 0.7% at anaphase I in the hybrid of Guinong 22 x common wheat Chinese Spring and was 0.8%-1.7% at anaphase II in two wheat-Haynaldia hybrids. Otherwise, the chromosome morphology involving Haynaldia chromatin was observed at preleptotene I, and the frequencies of chromatin nucleus at tetrad stage and at microspore stage were investigated. The time of chromosome translocation in meiosis and the transmitting frequencies of Haynaldia chromosome in wheat background were discussed.


Assuntos
Translocação Genética , Triticum/genética , Frequência do Gene , Hibridização in Situ Fluorescente , Meiose/genética
3.
Sci China B ; 32(12): 1436-48, 1989 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-2574978

RESUMO

This paper reports the changes of the EEG of human bodies during saturation exposure at different depths to different mixed gases. The results of the research show that the most obvious on EEG was the appearance of diffused slow waves, usually theta waves of 4-7 times/s, and delta waves of 2-3 times/s within individual subjects. The EEG changes at 50 m were more obvious than those at 36.5 m. With the prolonging of time under high pressure, the EEG had some improvements, for instance, the slow waves decreased and the alpha waves increased. There was a certain relationship between these changes and the symptoms which appeared in the human body. The chief factor of the EEG changes is due to the effect of nitrogen narcosis during the oxygen-nitrogen diving experiment. In addition, carbon dioxide retention under the high pressure is also a factor of the EEG changes, because repeated inhaling of CO2-dense mixtures could aggravate the EEG changes and the reduction of carbon dioxide in humans by hyperventilation could improve abnormal EEGs. The main changes of the EEG during the helium-oxygen exposure at 302 m were the increase of theta waves, and even of delta waves, the decrease in alpha rhythm and the decline of amplitude of alpha waves. Increased theta index and decreased alpha index could be seen at the depth of 302 m. Under any of the above-mentioned pressure conditions when slow waves characteristic of abnormal changes appeared in the EEGs, the EEGs could be temporarily improved by photic stimulation, i.e. slow waves disappeared and alpha waves reappeared. When photic stimulation was over, alpha waves disappeared and slow waves reappeared. It was indicated that abnormal changes of the EEG under high pressure were a kind of temporary and reversible changes of the brain function.


Assuntos
Mergulho , Sistemas Ecológicos Fechados , Eletroencefalografia/efeitos dos fármacos , Hélio/farmacologia , Nitrogênio/farmacologia , Oxigênio/farmacologia , Adulto , Pressão Atmosférica , Humanos , Masculino
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