Zr—4合金单调和循环变形结构的扫描电镜原位观察

利用ＳＥＭ原位观察了Ｚｒ－４合金单调和循环变形过程中,试样表面滑移,裂纹萌生及扩展特征。结果表明：拉伸过程中,随着外应力增大,滑移程度加剧,从单滑移逐渐向多滑移转化;     

A Non-Uniform Predictor-Observer for a Networked Control System

International Journal of Control, Automation and Systems - This paper presents a Non-Uniform Predictor-Observer (NUPO) based control approach in order to deal with two of the main problems related...     

Structural design of carbon/epoxy bio‐inspired wind turbine blade using fluid/structure simulation

The purpose of this paper is to present the structural design procedure of a low‐speed, horizontal axis, bio‐inspired wind turbine blade made of carbon/epoxy. The methodology initiates with the mechanical characterization of the carbon fiber composite material. An aerodynamic simulation using Computational Fluid Dynamics (CFD) method is performed in order to obtain the pressure distribution profile of the blade. This result is coupled with a Finite Element Analysis (FEA) to carry out an iterative design process through a Fluid‐Structure Interaction (FSI) simulation. Different stacking sequences of laminates are evaluated to find a configuration which allows balance between aerodynamic and dynamic inertial loads, ensuring an almost undeformed geometry during wind turbine's operation. The final structural design of the blade consists in six regions with different laminates. These are balanced and symmetric with distinct thickness characteristics and stacking sequences, which vary in three different orientations: 0^°, ± 45^° and 90^°, achieving a minimum deflection at the tip close to 3.11 cm, and a total weight of 3.6 kg of a 1.8 m radius blade, even with the restrictions imposed by the non‐conventional geometry. Copyright © 2016 John Wiley & Sons, Ltd.     

Correlation lengths, porosity and water adsorption in TiO₂ thin films prepared by glancing angle deposition

This paper reports a thorough microstructural characterization of glancing angle deposited (GLAD) TiO(2) thin films. Atomic force microscopy (afm), grazing-incidence small-angle x-ray scattering (GISAXS) and water adsorption isotherms have been used to determine the evolution of porosity and the existence of some correlation distances between the nanocolumns constituting the basic elements of the film's nanostructure. It is found that the deposition angle and, to a lesser extent, the film thickness are the most important parameters controlling properties of the thin film. The importance of porosity and some critical dimensions encountered in the investigated GLAD thin films is highlighted in relation to the analysis of their optical properties when utilized as antireflective coatings or as hosts and templates for the development of new composite materials.     

Tuning ratios, densities, and supramolecular spacing in bifunctional DNA-modified gold nanoparticles

Methods for combining multiple functions into well-defined nanomaterials are still lacking, despite their need in nanomedicine and within the broader field of nanotechnology. Here several strategies for controlling the amount and the ratio of combinations of labeled DNA on 13-nm gold nanoparticles using self-assembly of thiolated DNA and/or DNA-directed assembly are explored. It is found that the self-assembly of mixtures of fluorescently labeled DNA can lead to a higher amount of labeled DNA per particle; however, the ratio of fluorophores on the nanoparticles differs greatly from that in the self-assembly solution. In contrast, when fluorescently labeled DNA are hybridized to DNA-modified gold nanoparticles, the fluorophore ratio on the nanoparticles is much closer to their ratio in solution. The use of bifunctional DNA-doublers in self-assembly and DNA-directed assembly is also explored to increase the complexity of these materials and control their composition. Finally, tuning the distance between the labels from 2.9 to 5.4 nm was achieved using different hybridized DNA clamp complexes. Fluorescent results suggest that assembling these clamps on nanoparticle surfaces may be possible, although the resulting label spacing could not be quantified.     

激光表面改性提高钛合金耐磨性能的研究进展

分析了各种钛合金激光表面改性工艺、涂层材料体系的最新研究进展,指出了目前钛合金表面改性过程中存在的问题,总结了当前抑制涂层裂纹产生的措施,提出了钛合金激光表面改性进一步的研究方向.