垂直铺塑和深层搅拌桩墙在土堤(坝)垂直防渗中的应用

垂直铺塑和深层搅拌防渗技术是近年来发展起来的新的提(坝)垂直防渗技术。通过工程实践，总结了这2项技术的适应条件、防渗机理，分析了其防渗的可靠性、经济性及发展前景，提供了垂直铺塑和深层搅拌的施工工艺和施工经验。     

大掺量统排粉煤灰混凝土渠道防渗技术的研究

通过粉煤灰混凝土抗压强度、抗渗、抗冻等技术性能的试验对比以及机理分析 ,提出了满足渠道防渗工程规范要求的粉煤灰混凝土经济合理的配合比 ,为渠道粉煤灰混凝土防渗工程技术的推广应用提供了科学依据。选用混凝土复合外加剂 ,解决了大掺量统排粉煤灰混凝土早期强度低、机制薄壁渠槽难以快速成型的关键技术。在确保抗压、抗冻、防渗效果等性能要求的前提下 ,粉煤灰混凝土较普通混凝土节省水泥用量 4 0 % ,节省投资 1 5 %以上     

Recent innovations in barrier technologies for plastic packaging—a review

The barrier solutions presently available on the market all have their drawbacks, e.g. cost, water‐sensitivity, opacity or perceived environmental bad‐will. At the same time there is a trend to use more plastic‐based packaging materials for different applications, e.g. as replacements for metal and glass containers. This situation has stimulated the industry to provide new, more efficient barrier solutions. The innovations go along five major lines: (a) thin, transparent vacuum‐deposited coatings; (b) new barrier polymers as discrete layers; (c) blends of barrier polymers and standard polymers; (d) organic barrier coatings; and (e) nanocomposite materials. This paper provides a comprehensive review of the different approaches, outlining the principle behind each barrier technology, its performance, its potential and the companies developing and producing the materials. Copyright © 2003 John Wiley & Sons, Ltd.     

GaN基可见盲紫外探测器及其研究进展

介绍了GaN基的3种可见盲紫外光探测器：p-i-n结、肖特基势垒和金属-半导体-金属紫外光探测器，并对其工作原理、特性和发展现状进行了综述。     

Titanium nitride diffusion barrier for copper metallization on gallium arsenide

The diffusion properties of Cu, Cu/titanium nitride (TiN) and Cu/TiN/Ti metallization on GaAs, including as-deposited film and others annealed at 350-550 °C, were investigated and compared. Data obtained from X-ray diffractometry, resistivity measurements, scanning electron microscopy, energy dispersive spectrometer and Auger electron spectroscopy indicated that in the as-deposited Cu/GaAs structure, copper diffused into GaAs substrate, and a diffusion barrier was required to block the fast diffusion. For the Cu/TiN/GaAs structure, the columnar grain structure of TiN films provided paths for diffusion at higher temperatures above 450 °C. The Cu/TiN/Ti films on GaAs substrate were very stable up to 550 °C without any interfacial interaction. These results show that a TiN/Ti composite film forms a good diffusion barrier for copper metallization with GaAs.     

Magnetic tunnel junctions with doubly-plasma oxidized AlOx insulation layer

Magnetic tunnel junctions (MTJ), with the tunnel barrier plasma oxidized in two steps, were fabricated in order to obtain structurally uniform AlO_x insulator. The doubly oxidized junctions exhibited the magnetoresistance (MR) ratio of 27-31% without showing any noticeable drop in the MR ratio even after oxidation time was extended well beyond the optimal oxidation time for the normal junctions. Transmission electron microscopy of the junctions confirmed that the AlO_x thickness was thinner for the doubly oxidized junctions compared to the singly oxidized MTJ. X-ray photoelectron spectroscopy of the doubly oxidized junction also strongly suggested that the initial oxide layer prevents the over-oxidation of the bottom electrode. The AlO_x tunnel barrier oxidized in two steps improved the junction performance and widened the processing window.     

共振隧穿二极管(RTD)的物理模型——共振隧穿器件讲座(3)

介绍了共振隧穿二极管物理模型的量子力学基础,重点讲解共振隧穿两种物理模型,从不同维度隧穿的特点分析共振隧穿和非共振隧穿的区别,为以后讨论分析共振隧穿器件的特性奠定基础。     

水泥搅拌桩技术在泔河水库工程中的应用

水泥搅拌桩技术近年来被广泛应用于建筑地基加固、基坑的开挖支挡、堤防的防渗加固等,均取得了比较满意的效果。但是在水库的除险加固工程中应用还比较少见。通过详细分析论证,最终把水泥搅拌桩这项技术推广应用于泔河水库除险加固工程的实际。     

浅论抗渗混凝土试块安装

介绍了做混凝土抗渗试验所采用的蜡封试块的安装方法 ,从原理、操作方法、材料、工具设备、安全措施等方面加以阐述 ,指出该方法具有安装速度快 ,密封性好 ,安全性高的优点     

温峡口水库大坝除险加固技术方案研究

温峡口水库是全国首批重点病险水库之一,大坝存在严重的渗漏破坏问题,多次直接灌浆试验均未获成功,曾多年做过多种工程方案的比较,因大多存在经济或技术上的困难而未付诸实施.提出采用高压喷射灌浆技术建筑一定高度的连续高喷墙体,截断基岩表层裂隙和强风化层的渗漏并形成灌浆盖板,进而实施基岩防渗帷幕灌浆,经现场试验,该方案获得成功,并于温峡口水库大坝除险加固工程中付诸实施.