Al/MoO3薄膜厚度对含能半导体桥发火特性的影响

使用微细加工技术在半导体桥上分别集成3μm和6μm厚度的Al/MoO_3纳米含能复合薄膜,制备成含能半导体桥,并使用电容放电的激发方式,研究薄膜厚度对含能半导体桥发火特性的影响。研究发现,随着薄膜厚度的增加,含能半导体桥的临界发火时间和临界发火能量无显著性变化,电容放电的作用总时间、作用总能量和能量利用效率降低,能量输出效率显著增加。     

Multi‐contrast MR image denoising for parallel imaging using multilayer perceptron

For clinical diagnosis in MRI, multiple examinations are commonly performed to acquire various contrast images. This article presents a learning‐based denoising method for parallel imaging to enhance the quality of multi‐contrast images so that the imaging time can be accelerated highly. Multi‐contrast images share structural information and coil geometry. The proposed method adopts the multilayer perceptron (MLP) model to save the sharable and redundant information among the multi‐contrast images. The images are divided into patches, which are used as the input and output of MLP. A geometry factor map is additionally used to provide noise amplification information of the accelerated MR images. Computer simulation demonstrates that the use of multi‐contrast images and geometry factor contributes to the quality of the reconstructed images. The proposed method reconstructs high‐quality images without impairing details from the subsampled intermediate images, and it shows better results than previous denoising methods.     

Average power handling capability of multilayer microstrip lines

This article describes the average power handling capability (APHC) of multilayer microstrip lines, including the effect of mismatch at the terminations. The data presented herein are validated by considering an example of a 12‐W monolithic microwave integrated circuit power amplifier fabricated using multilayer low‐loss microstrip technology. The calculated value of APHC for a 50‐Ω line of a 75‐μm‐thick GaAs substrate is 1445 W at 10 GHz, whereas the corresponding value for a multilayer microstrip that has 10‐μm‐thick polyimide is only 44 W. At 40 GHz, these values are reduced by a factor of 2. © 2001 John Wiley & Sons, Inc. Int J RF and Microwave CAE 11: 385–395, 2001.     

Electrostatic Assembly with Poly(ferrocenylsilanes)

New frontiers in polymer science involve the incorporation of functional species into material systems. The electrostatic layer-by-layer (LBL) self-assembly technique constitutes a versatile tool for nano- and microscale fabrication of devices and novel material structures. Although a rapidly growing attention has been paid to this area, most of the studies conducted were based on organic polymeric electrolytes. Due to synthetic developments, new polymeric structures with inorganic elements and transition metals incorporated in the main chain have become accessible. With the development of new synthesis routes, organometallic poly(ferrocenylsilane) polycations and polyanions emerged. Their charged nature and water-solubility made them excellent candidates for the extension of electrostatic multilayer assembly to organometallic polymeric materials. The present review gives a concise summary on the LBL fabrication of organometallic thin films and microcapsules based on water-soluble poly(ferrocenylsilane) polyions. The unique functions of these structures come from the molecular structure of poly(ferrocenylsilanes), in which silicon atoms and redox-active ferrocene units are present. In this context, the diverse application potentials of these organometallic multilayer structures are also discussed. This article is dedicated to Professor Ian Manners in honor of his great scientific accomplishments, with friendship and sincere respect.     

国外云母系珠光颜料研究的新进展

综述了近期国外云母系珠光颜料开发研究的最新进展，分析了多覆层云母珠光颜料能提高遮盖力的原因，阐述了具有高着色能力的有机着色类云母珠光颜料合成研究的现状     

Damage Localisation in a Stiffened Composite Panel

Abstract:  This work was conducted as part of the Aircraft Reliability Through Intelligent Materials Application (ARTIMA) European Union project. It presents a case study of damage detection in a curved carbon-fibre reinforced panel with two omega stiffeners which was investigated using ultrasonic Lamb waves. The statistical technique of outlier analysis was used here as a way of pre-processing experimental data prior to damage classification. Multilayer perceptron neural networks were used here for both classification and regression problems of damage detection. It was then investigated whether using wavelet analysis to perform prior wavelet decompositions of experimental data could facilitate damage classification.     

桅杆结构的纤绳工作研究

桅杆结构是由柔软的纤绳和细长的杆身组成,其大变形及强非线性使得动力特性十分复杂。在正常设计、建造情况下桅杆破坏发生的比例之高在土木建筑中是罕见的。通过对桅杆结构的多层纤绳的初应力分析,来研究纤绳初应力对多层纤绳桅杆结构工作性能的影响。     

Analysis of the stress-strain condition of a multilayer road surface

The problem is solved of the axiasymmetric loading of a multilayer road surface modeled with the multilayer coating adhering to an elastic base. Analysis of the stresses evolving in the layers and interfaces enables us to estimate the probability of various types of coating failure. The effect of the elastic properties of the road-surface layers on the maximum stresses and displacements is considered. It is shown that the interfaces between the layers are concentrators of stresses.     

纳米SiO2制备及改性

为了改善纳米SiO2的分散性,用溶胶-凝胶技术制备了纳米SiO2凝胶,并用不同改性剂对粉末进行了表面改性.采用透射电子显微镜(TEM)、X射线衍射(XRD)、粒度分析仪(PSA)、紫外-可见光分光光度计(UV-VS)等分析了纳米SiO2的粒径及分散性.结果表明,正硅酸乙酯的水解和缩合反应条件直接影响纳米SiO2粉体的粒径大小.KH-550硅烷偶联改性剂用量、改性时间等因素对改性效果有明显的影响.当改性剂用量为4.1%(质量分数),改性时间为2h时,可得到高分散性的纳米SiO2粉体.纳米SiO2粉末易发生团聚,只有对其进行表面改性,才能得到疏水性纳米SiO2粉末.