Structural and optical properties of CdTe-nanocrystals thin films grown by chemical synthesis

By mans of a chemical synthesis technique stoichiometric CdTe-nanocrystals thin films were prepared on glass substrates at 70 °C. First, Cd(OH)₂ films were deposited on glass substrates, then these films were immersed in a growing solution prepared by dissolution of Te in hydroxymethane sulfinic acid to obtain CdTe. The structural analysis indicates that CdTe thin films have a zinc-blende structure. The average nanocrystal size was 19.4 nm and the thickness of the films 170 nm. The Raman characterization shows the presence of the longitudinal optical mode and their second order mode, which indicates a good crystalline quality. The optical transmittance was less than 5% in the visible region (400–700 nm). The compositional characterization indicates that CdTe films grew with Te excess.     

Rectangular Section Control Technology for Silicon Steel Rolling

Rectangular section control technology(RSCT)was introduced to achieve high-precision profile control during silicon steel rolling.The RSCT principle and method were designed,and the whole RSCT control strategy was developed.Specifically,RSCT included roll contour design,rolling technology optimization,and control strategy development,aiming at both hot strip mills(HSMs)and cold strip mills(CSMs).Firstly,through the high-performance variable crown(HVC)work roll optimization design in the upper-stream stands and the limited shifting technology for schedule-free rolling in the downstream stands of HSMs,a hot strip with a stable crown and limited wedge,local spot,and single wave was obtained,which was suitable for cold rolling.Secondly,an approximately rectangular section was obtained by edge varying contact(EVC)work roll contour design,edge-drop setting control,and closed loop control in the upper-stream stands of CSMs.Moreover,complex-mode flatness control was realized by coordinating multiple shape-control methods in the downstream stands of CSMs.In addition,the RSCT approach was applied in several silicon-steel production plants,where an outstanding performance and remarkable economic benefits were observed.     

The analysis and comparison of two novel kinds of focusing elements as reflectors

In this article, two novel kinds of focusing elements as reflectors are analyzed and compared. One is the grooved Fresnel zone plate reflector with continuous phase‐correcting. The other called subzone paraboloid reflector, has the profile that consists of a series of paraboloids. Their diffraction efficiencies and bandwidths are described. The two elements still preserve the advantages of Fresnel zone plates, namely, low profile, high efficiency, and simple fabrication. Two dual‐reflector antennas using the proposed focusing elements as the main reflectors are simulated and the results show that these antennas have good radiation performances. © 2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:101–108, 2015.     

Formation of ST12 phase Ge nanoparticles in ZnO thin films

In this work, we focus on the Ge nanoparticles (Ge-np) embedded ZnO multilayered thin films. Effects of reactive and nonreactive growth of ZnO layers on the rapid thermal annealing (RTA) induced formation of Ge-np have been specifically investigated. The samples were deposited by sequential r.f. and d.c. sputtering of ZnO and Ge thin film layers, respectively on Si substrates. As-prepared thin film samples have been exposed to an ex-situ RTA at 600 °C for 60 s under forming gas atmosphere. Structural characterizations have been performed by X-ray Diffraction (XRD), Raman scattering, Secondary Ion Mass Spectroscopy (SIMS), and Scanning Electron Microscopy (SEM) techniques. It has been realized that reactive or nonreactive growth of ZnO layers significantly influences the morphology of the ZnO: Ge samples, most prominently the crystal structure of Ge-np. XRD and Raman analysis have revealed that while reactive growth results in a mixture of diamond cubic (DC) and simple tetragonal (ST12) Ge-np, nonreactive growth leads to the formation of only DC Ge-np upon RTA process. Formation of ST12 Ge-np has been discussed based on structural differences due to reactive and nonreactive growth of ZnO embedding layer.     

新型高K栅介质ZrO2薄膜材料的制备及表征

采用超高真空电子束蒸发法制备了新型高 K栅介质-非晶 ZrO2薄膜. X射线光电子能谱 (XPS) 中 Zr3d5/2 和 Zr3d3/2 对应的结合能分别为 182.1eV和 184.3eV, Zr元素的主要存在形式为 Zr4+,说明薄膜由完全氧化的 ZrO2组成 ,并且纵向分布均一.扩展电阻法( SRP)显示 ZrO2薄膜的 电阻率在 108Ω@ cm以上,通过高分辨率透射电镜( HR- XTEM)可以观察 ZrO2/Si界面陡直,没有 界面反应产物 ,证明 600℃快速退火后 ZrO2薄膜是非晶结构.原子力显微镜( AFM)表征了薄膜的 表面粗糙度,所有样品表面都很平整,其中 600℃快速退火样品 (RTA)的 RMS为 0.480nm.     

热镀锌板(卷)工程设计中的环境保护问题

对热镀锌板(卷)的生产工艺、主要生产设备进行了简要介绍，并就其污染源(工序)、生产过程中产生的污染物及其控制措施进行了评述，同时就设计和生产中宜注意的几个环保问题进行了分析。     

多孔板体结构足尺性能分析及材料基本要求

本文就利用诸如蛋白石这样的疏松多孔矿料同灰土构成的混合料，在路面结构中表现出的独特有效的抗冻作用机理作了深入分析，并结合足尺试验数据加以验证。阐述了所谓多孔板体结构的概念、机制和材料组成要求。     

The microstructure of Cu films deposited by the self-ion assisted technique

The microstructures of Cu films deposited by the self-ion assisted, partially ionized beam (PIB) deposition technique under two different accelerating potentials, 0 KeV and 6 KeV, are compared. The 6 KeV film shows a bimodal (111) fiber and (100) fiber texture with an abundance of twin boundaries and a relatively large average grain size with a typical lognormal distribution. The 0 KeV film consists of small, mostly (111) oriented grains with islands of abnormally large (100) grains. The controlling factors for the abnormal growth of the (100) grains are discussed in relation to the observed microstructures, showing that all factors necessary for abnormal (100) growth are present in the films.     

消力池底板块的失稳破坏机理及其防护措施

本文根据国内外一些高坝消力池和水垫塘失事破坏的调查资料，说明了脉动压力在引起破坏中的作用。从理论上分析了脉动压力的基本特征及其分布规律、板块上脉动上举力的产生机理，论证了脉动上举力是导致消力池底板揭底破坏的主要原因。论述了合理设置止水设施、排水设施以及锚固措施等对防止破坏的效果，讨论了计入脉动荷载的底板块稳定性设计准则，提供了消力池底板块的设计和防护参数。