硅纳米线界面态的化学钝化方法概述

分析了界面态对硅无结纳米线晶体管（JNT）亚阈值摆幅和电导率的影响,并详细总结了化学钝化硅纳米线界面态的方法以及对器件性能的影响。化学钝化方法主要包括各向同性的氢氟酸（HF）腐蚀钝化和各向异性的四甲基氢氧化铵（TMAH）腐蚀钝化。HF钝化方法以氢饱和硅表面悬挂键来减少其表面界面态,TMAH钝化方法则通过各向异性腐蚀形成Si—O键。化学处理后得到了光滑的硅纳米线晶面表面结构,从而有效地抑制界面态对电导率的影响,使器件达到理想的亚阈值摆幅。研究结果表明,利用化学腐蚀钝化方法优化界面态,能够有效改善硅纳米线晶体管的性能。

舒芬太尼联合丙泊酚在小儿麻醉中的临床效果

目的探讨分析舒芬太尼+丙泊酚在小儿麻醉中的临床效果。方法选取我院自2017年2月—2018年3月收治的80例小儿患者作为本次临床研究对象,并将其分为对照组(n=40)与观察组(n=40),其中对照组患儿给予舒芬太尼,观察组患儿给予舒芬太尼+丙泊酚,对比两组患儿经用药后的临床效果。结果所有患儿经麻醉用药后,其中观察组患儿的麻醉诱导时间、苏醒时间及其苏醒期躁动评分低于对照组,组间对比差异有统计学意义(P <0.05)。结论对小儿患者在临床治疗中给予舒芬太尼联合丙泊酚用药,能进一步提高临床效果,减少患儿苏醒期躁动情况的发生,值得在临床中应用。

Observation of hopping transitions for delocalized electrons by temperature-dependent conductance in silicon junctionless nanowire transistors

We demonstrate transitions of hopping behaviors for delocalized electrons through the discrete dopant-induced quantum dots in n-doped silicon junctionless nanowire transistors by the temperature-dependent conductance characteristics.There are two obvious transition platforms within the critical temperature regimes for the experimental conductance data,which are extracted from the unified transfer characteristics for different temperatures at the gate voltage positions of the initial transconductance gm peak in Vg1 and valley in Vg2. The crossover temperatures of the electron hopping behaviors are analytically determined by the temperature-dependent conductance at the gate voltages Vg1 and Vg2. This finding provides essential evidence for the hopping electron behaviors under the influence of thermal activation and long-range Coulomb interaction.

Influence of dopant concentration on electrical quantum transport behaviors in junctionless nanowire transistors

We discuss the random dopant effects in long channel junctionless transistor associated with quantum confinement effects. The electrical measurement reveals the threshold voltage variability induced by the random dopant fluctuation. Quantum transport features in Hubbard systems are observed in heavily phosphorus-doped channel. We investigate the single electron transfer via donor-induced quantum dots in junctionless nanowire transistors with heavily phosphorus- doped channel, due to the formation of impurity Hubbard bands. While in the lightly doped devices, one-dimensional quantum transport is only observed at low temperature. In this sense, phonon-assisted resonant-tunneling is suppressed due to misaligned levels formed in a few isolated quantum dots at cryogenic temperature. We observe the Anderson-Mott transition from isolate electron state to impurity bands as the doping concentration is increased.

25G腰麻针在剖宫产腰麻中的直接应用疗效分析

硬膜外麻醉和腰硬联合麻醉是一直被广泛应用于剖宫产手术的麻醉,但麻醉后严重腰痛的发生率为5%左右,主要与穿刺针引起的背部肌肉韧带损伤有关。因此,如何减少此麻醉并发症是困扰麻醉医生的难题。我科自2009年9月开始,在剖宫产手术中直接使用25G腰麻针行腰麻穿刺,麻醉效果确切。现报告如下。

Temperature-dependent subband mobility characteristics in n-doped silicon junctionless nanowire transistor

We have investigated the temperature-dependent effective mobility characteristics in impurity band and conduction subbands of n-doped silicon junctionless nanowire transistors. It is found that the electron effective mobility of the first subband in 2-fold valleys is higher than that of the second subband in 4-fold valleys. There exists a maximum value for the effective subband mobilities at low temperatures, which is attributed to the increase of thermally activated electrons from the ionized donors in the impurity band. The experimental results indicate that the effective subband mobility is temperature-dependent on the electron interactions by thermal activation, impurity scattering, and intersubband scattering.

Transport spectroscopy through dopant atom array in silicon junctionless nanowire transistors

We demonstrate electron transport spectroscopy through a dopant atom array in n-doped silicon junctionless nanowire transistors within a temperature range from 6 K to 250 K. Several current steps are observed at the initial stage of the transfer curves below 75 K, which result from the electron transport from Hubbard bands to one-dimensional conduction band. The current-off voltages in the transfer curves have a strikingly positive shift below 20 K and a negative shift above 20 K due to the electrostatic screening induced by the ionized dopant atoms. There exists the minimum electron mobility at a critical temperature of 20 K, resulting from the interplay between thermal activation and impurity scattering. Furthermore, electron transport behaviors change from hopping conductance to thermal activation conductance at the temperature of 30 K.