窄带Mo／Si多层膜反射镜

设计并制备了窄带M o/S i多层膜反射镜。利用高反射级次和减小M o层厚度两种方法减小M o/S i多层膜反射镜光谱宽度。对M o层厚度分别为2 nm和3 nm的M o/S i多层膜,设计了反射级次分别从1到6的多层膜系。制备方法采用直流磁控溅射技术,在国家同步辐射光谱与计量站上测试。结果表明,带宽随着反射级次增加而减少,在同一反射级次,M o层厚度为2 nm的多层膜反射光谱带宽较小。     

退火温度对宽带脉冲压缩光栅载体金属/介质多层高反膜的影响

分别以金(Au)作为金属层材料, 氧化铪(HfO₂)与氧化硅(SiO₂)作为高低折射率层材料, 利用物理气相沉积方法制备了用于宽带脉冲压缩光栅制作的金属/介质多层高反膜, 研究了退火温度对其表面均方根粗糙度、反射率及抗化学清洗破坏能力的影响。实验结果表明: 退火前后样品表面均方根粗糙度变化很小; 提高退火温度能提高金属/介质多层膜的抗化学清洗破坏能力, 但反射率会随之下降。250℃退火10 h后金属/介质多层膜不仅可以承受住化学清洗过程, 而且反射率下降也比较小, 可以作为金属/介质多层膜的最佳退火工艺。     

电磁波在磁性分层薄膜中的传播非互易反射

本文采用传输矩阵研究了电磁波在磁性多层膜和超晶格中的透射和反射,获得了层状磁性介质的透射和反射系数,包括:(1)半无限磁性表面,(2)磁性多层膜,(3)半无限磁性超晶格。数值计算结果表明,磁性分层系统中电磁表面模可以通过电磁波斜入射在膜面上而激发出来,表现为S-极化反射曲线的尖谷,因此,本文指出电磁波传播的色散曲线可以用一种类似衰减全反射(ATR)的技术来测量。     

多层LEMs性能与结构参数的关系

建立一多层LEMs柔顺机构的一般伪刚体模型.基于LET铰链等效弹簧刚度模型,推导出LEMs输入载荷和输出角位移的一般理论计算公式.分析了影响机构角位移输出的主要结构参数,以及相同载荷下这些参数对角位移输出的影响趋势.根据分析结果,对机构实例的结构尺寸参数设计了一组初始值.通过实例的理论计算与有限元仿真,分析得到机构的LET外铰链扭转片段长度和宽度尺寸变化对角位移和误差的不同影响效果.     

Microstructure and Magnetic Properties of Electrodeposited Fe-Based Thin Films on Silicon Substrate Under Heat Treatment

Three kinds of Fe-based thin films, Fe–20%Ni–80%, Fe–60%Co–40%, and Fe–10%Ni–60%Co–30% (at %), were prepared on silicon (1 1 1) substrates by direct current electrodeposition with the optimized plating conditions. Films were annealed at various temperatures from 200 to 400 °C, varying time from 2 to 4 h. The microstructure, surface morphology, and chemical composition have been investigated by X-ray diffraction, scanning electron microscopy, energy dispersive spectrometer with electron probe micro-analysis, respectively. The magnetic properties were measured by the superconducting quantum interference device magnetometer. Effect of heat treatment on films is then discussed.     

Polyelectrolyte Multilayer-Treated Electrodes for Real-Time Electronic Sensing of Cell Proliferation

We report on the use of polyelectrolyte multilayer (PEM) coatings as a non-biological surface preparation to facilitate uniform cell attachment and growth on patterned thin-film gold (Au) electrodes on glass for impedance-based measurements. Extracellular matrix (ECM) proteins are commonly utilized as cell adhesion promoters for electrodes; however, they exhibit degradation over time, thereby imposing limitations on the duration of conductance-based biosensor experiments. The motivation for the use of PEM coatings arises from their long-term surface stability as promoters for cell attachment, patterning, and culture. In this work, a cell proliferation monitoring device was fabricated. It consisted of thin-film Au electrodes deposited with a titanium-tungsten (TiW) adhesion layer that were patterned on a glass substrate and passivated to create active electrode areas. The electrode surfaces were then treated with a poly(ethyleneimine) (PEI) anchoring layer and subsequent bilayers of sodium poly(styrene sulfonate) (PSS) and poly(allylamine hydrochloride) (PAH). NIH-3T3 mouse embryonic fibroblast cells were cultured on the device, observed by optical microscopy, and showed uniform growth characteristics similar to those observed on a traditional polystyrene cell culture dish. The optical observations were correlated to electrical measurements on the PEM-treated electrodes, which exhibited a rise in impedance with cell proliferation and stabilized to an approximate 15 % increase as the culture approached confluency. In conclusion, cells proliferate uniformly over gold and glass PEM-treated surfaces, making them useful for continuous impedance-based, real-time monitoring of cell proliferation and for the determination of cell growth rate in cellular assays.     

Multiple crack problem in nonhomogeneous composite materials subjected to dynamic anti-plane shearing

A recently developed method for the dynamic response of nonhomogeneous composite material subjected to in plane loading is further extended to accommodate the case of anti-plane loading. It is assumed that the composite material is orthotropic and all the material properties vary arbitrarily along the thickness direction. In the analysis, the elastic region is modeled using a series of layers of infinite length, with each layer having slightly different properties. By utilizing the Laplace transform and Fourier transform technique, the general solution for each layer is derived. The singular integral equations of the entire elastic region are then obtained through introducing the mechanical boundary and layer interface conditions via the flexibility/stiffness matrix approach. The integral equations are solved by weighted residual value method. As the numerical illustrations, the dynamic stress intensity factors for a cracked metal-ceramic joint with a functionally graded interlayer under sudden applied stress on the joint surface are presented. The results demonstrate that there existing optimal nonhomogeneity parameter at which the stress intensity factor is minimized.     

Influences of surface chemistry and swelling of salt-treated polyelectrolyte multilayers on migration of smooth muscle cells

The cell migration plays a crucial role in a variety of physiological and pathological processes and can be regulated by the cell–substrate interactions. We found previously that the poly(sodium 4-styrenesulphonate) (PSS)/poly(diallyldimethylammonium) chloride (PDADMAC) multilayers post-treated in 1–5 M NaCl solutions result in continuous changes of their physico-chemical properties such as thickness, chemical composition, surface charge, swelling ratio and wettability. In this study, the responses of human smooth muscle cells (SMCs) on these salt-treated multilayers, particularly the governing factors of cellular migration that offer principles for designing therapeutics and implants, were disclosed. The cell migration rate was slowest on the 3 M NaCl-treated multilayers, which was comparable with that on tissue culture plates, but it was highest on 5 M NaCl-treated multilayers. To elucidate the intrinsic mechanisms, cell adhesion, proliferation, adhesion and related gene expressions were further investigated. The SMCs preferred to attach, spread and proliferate on the PSS-dominated surfaces with well-organized focal adhesion and actin fibres, especially on the 3 M NaCl-treated multilayers, while were kept round and showed low viability on the PDADMAC-dominated surfaces. The relative mRNA expression levels of adhesion-related genes such as fibronectin, laminin and focal adhesion kinase, and migration-related genes such as myosin IIA and Cdc42 were compared to explain the different cellular behaviours. These results reveal that the surface chemistry and the swelling of the salt-treated multilayers govern the cell migration behaviours.     

计算机信息防泄复合薄膜屏蔽材料设计─Ⅰ．理论部分

本文在计算机信息防泄复合薄膜屏蔽材料研究中，引入材料设计的思想，运用传输线的理论模型，借助于计算机，对不同材料进行多层屏蔽设计。计算结果表明，非磁性导体间的多层复合，屏蔽效果随分层数的增加而趋于一极大值，但变化值很小；磁性导体的多层复合，屏蔽效果与分层数存在着最佳的匹配关系，并随频率、膜厚、成分变化而变化；金属与铁氧体的复合，仅当屏蔽衰减较大时（膜较厚），铁氧体对屏蔽才起明显作用，分层才有意义。