lift⁃off制程PEB温度对负性光阻显影后截面Profile的影响

本文研究了lift⁃off(揭开-剥离)制程曝光后烘烤温度(post exposure bake,PEB)对负性光阻显影截面Profile(光刻胶结构)的影响。结果表明:在保留原有PEB盘面加热的方式前提下通过增加PEB盘盖加热功能进行烘烤,通过控制PEB盘面温度可调整光阻关键尺寸(critical dimension,CD)及截面Profile形貌,通过控制PEB盘盖加热可调整截面Profile光阻顶端形貌及强度,可显著改善负性光阻显影后截面Profile难以调整的问题。另外,不同的盘面温度、不同盘盖温度以及不同的显影时间相互配合,可以实现一种负性光阻产生不同截面光刻胶结构效果,可以实现同种光阻lift⁃off制程多样化。

光电子技术的又一重大发展——光子晶体及其应用

光子晶体就是指具有周期性结构的材料,其周期尺度为光波长的数量级。这种光子晶体具有“光半导体”功能,其应用前景无限广阔,有可能成为一个巨大的产业。

新型“纸”——TYVEK

本文主要介绍一种新型“纸”——纺粘型烯烃——TYVEK的生产流程、特点和用途。

Effects of Lactobacillus plantarum on gut barrier function in experimental obstructive jaundice

AIM:To investigate the mechanisms of Lactobacillus plantarum(L.plantarum)action on gut barrier in preoperative and postoperative experimental obstructive jaundice in rats.METHODS:Forty rats were randomly divided into groups of sham-operation,bile duct ligation(BDL),BDL +L.plantarum,BDL+internal biliary drainage(IBD),and BDL+IBD+L.plantarum.Ten days after L.plantarum administration,blood and ileal samples were collected from the rats for morphological examination,and intestinal barrier function,liver function,intestinal oxidative stress and protein kinase C(PKC)activity measurement.The distribution and expression of the PKC and tight junction(TJ)proteins,such as occludin,zonula occludens-1,claudin-1,claudin-4,junction adhesion molecule-A and F-actin,were examined by confocal laser scanning microscopy,immunohistochemistry,Western blotting,real-time fluorescent quantitative polymerase chain reaction assay.RESULTS:L.plantarum administration substantially restored gut barrier,decreased enterocyte apoptosis,improved intestinal oxidative stress,promoted the activity and expression of protein kinase(BDL vs BDL+L.plantarum,0.295±0.007 vs 0.349±0.003,P<0.05;BDL+IBD vs BDL+IBD+L.plantarum,0.407±0.046 vs 0.465±0.135,P<0.05),and particularly enhanced the expression and phosphorylation of TJ proteins in the experimental obstructive jaundice(BDL vs BDL+L.plantarum,0.266±0.118 vs 0.326±0.009,P<0.05).The protective effect of L.plantarum was more prominent after internal biliary drainage(BDL+IBD vs BDL +IBD+L.plantarum,0.415±0.105 vs 0.494±0.145,P<0.05).CONCLUSION:L.plantarum can decrease intestinal epithelial cell apoptosis,reduce oxidative stress,and prevent TJ disruption in biliary obstruction by activating the PKC pathway.

Insulation System of Power Transformers Behavior Comparison of Mineral Oils and Natural Ester Dielectric Fluids

Paper deals with a comparison of selected properties of several vegetable oil representatives along their accelerated thermal ageing at the temperature of 90 ℃. These properties are compared to two widely used and commercially available mineral transformer oils. A combined insulating system （an oil-paper system） was created with the usage of mentioned oils for measurement purposes. Dissipation factor, capacity and volume resistance are characteristics measured along a thermal ageing of the oil-paper systems. Infrared spectroscopy was used as an additional method. After 1,000 hours of ageing, the dissipation factor of all systems based on vegetable oils did not exceed the value of 0.015. The volume resistance of systems containing mineral oils was approx, twice as high as the volume resistance of those with vegetable oils. The capacity on the other hand was slightly lower in the case of mineral oils application. An experiment also showed that the paper combined with the vegetable oil dries more quickly than in combination with the mineral oil. Infrared spectroscopy has not shown any expressive changes in the chemical structure of aU tested oils yet （up to 1,000 hours of ageing）.

Properties of Creeping Streamer Progressed in Dielectric Barrier with Narrow Gap in PFAE Oil

The behaviors of creeping streamer progressed in the narrow gap with the range of 0.1 mm to 0.2 mm between the pressboard mounted a BSE （back side electrode） and the acrylic resin plate were carried out in PFAE （palm fatty acid ester） oil under variable impulse voltage up to -4-140 kVpeak with ＋1.2/50 μs and ±1.2/1,000μs waveforms. The growth of positive and negative streamers depends on the gap space between two solid dielectrics. And the distinctive polarities of impulse voltage affect in the streamer length and flashover voltage between needle and counter electrodes as well. By decreasing the gap space, the flashover voltage largely increased while the mean velocity of positive streamer significantly decreased under the both polarities of impulse voltage. These results have been compared to commercial mineral oil （transformer oil： JIS-C2320）. It is shown that the behaviors of creeping discharge in both oils elegantly reveal the distinctive phenomena.

An air-stable inverted photovoltaic device using ZnO as the electron selective layer and MoO_3 as the blocking layer

An air-stable photovoltaic device based on znic oxide nanoparticles （ZNP） in an inverted structure of indium tin oxide （ITO）/ZnO/poly （3-hexylthiophene） （P3HT）： [6,6]-phenyl C61-butyric acid methyl ester （PCBM）/MoO3/Ag is studied. We fm.d that the optimum thickness of the MoO3 layer is 2 nm. When the MoO3 blocking layer is introduced, the fill factor of the devices is increased from 29% to 40%, the power conversion efficiency is directly promoted from 0.35% to 1.27%.The stability under ambient conditions of this inverted structure device much is better due to the improved stability at the polymer/Ag interface. The enhancement is attributed to the high carriers mobility and suitable band gap of MoO3 layer.

Giant negative photoresistance of epitaxial manganite La_(2/3)Ca_(1/3)MnO_(3-δ) film

The La2/3Cal/3Mn03_σ film has been deposited on the （001） SrTiO3 substrate and its temper- ature-dependent photoconductive properties have been investigated from 80 to 300 K. The La2/3Cal/3MnO3-σ film has a novel photoelectric property due to its oxygen-deficient structure. We observed laser-induced giant negative photoresistance of the sample in a wide temperature range. The change rate of negative photoresistance was nearly 100% at the low temperature when the sample was irradiated by 532 nm laser. In addition, this effect was sensitive to the power of laser irradiation. The oxygen-deficiency of La2/3Cal/3Mn03-σ film seems to have an impact on the laser-induced resistance variation. The experimental results made the La2/3Cal/3MnO3_σ film a promising application as a photoswitch device.

Reversible optical control of the metal-insulator transition across the epitaxial heterointerface of a VO_(2)/Nb:TiO_(2) junction

Optical control of exotic properties in strongly correlated electron materials is very attractive owing to their potential applications in optical and electronic devices.Herein,we demonstrate a vertical heterojunction made of a correlated electron oxide thin film VO_(2) and a conductive 0.05 wt% Nb-doped TiO_(2) single crystal,whose metal-insulator transition(MIT)across the nanoscale heterointerface can be efficiently modulated by visible light irradiation.The magnitude of the MIT decreases from ~350 in the dark state to ~7 in the illuminated state,obeying a power law with respect to the light power density.The junction resistance is switched in a reversible and synchronous manner by turning light on and off.The optical tunability of it is also exponentially proportional to the light power density,and a 320-fold on/off ratio is achieved with an irradiance of 65.6 mW cm^(-2) below the MIT temperature.While the VO_(2) thin film is metallic above the MIT temperature,the optical tunability is remarkably weakened,with a one-fold change remaining under light illumination.These results are co-attributed to a net reduction(~15 meV)in the apparent barrier height and the photocarrier-injection-induced metallization of the VO_(2) heterointerface through a photovoltaic effect,which is induced by deep defect level transition upon the visible light irradiance at low temperature.Additionally,the optical tunability is minimal,resulting from the quite weak modulation of the already metallic band structure in the Schottky-type junction above the MIT temperature.This work enables a remotely optical scheme to manipulate the MIT,implying potential uncooled photodetection and photoswitch applications.

Electrochemical methods for the characterization and interfacial study of dye-sensitized solar cell

Dye-sensitized solar cell （DSSC） is one of the most rapidly developed solar cells in the past 20 years. Many characterization methods have been employed for further understanding the operational details of the photo- electric conversion in DSSC as well as the evaluation of cell performance. Electrochemical methods have become pow- erful tools for studying the charge transfer and interfacial process. In this review, we introduce and explain the various electrochemical methods used to characterize and analyze DSSC, including current-voltage （I-V） scan measurement, cyclic voltammetry, electrochemical impedance spec- troscopy, intensity-modulated photocurrent spectroscopy, and intensity-modulated photovoltage spectroscopy. In ad- dition, some applications were provided as samples to elucidate electron transfer kinetics, energy levels and electrocatalytic activity of the materials used in DSSC.