为提高钛合金的高温抗氧化性能, 采用激光熔覆原位自生技术, 在TC4钛合金表面自行设计并制备了原子百分比为Ti∶Al∶Si=41∶41∶18和Ti∶Al∶Si=35∶35∶30的两种涂层。通过XRD、OM、SEM表征了涂层的微观组织和物相组成; 借助管式电阻炉测试了涂层和基体试样在800 ℃×24 h×5次循环氧化条件下的高温抗氧化性能; 结合氧化增重和氧化动力学曲线分析了涂层的高温抗氧化机理。结果表明, 涂层主要由Ti5Si3、Ti7Al5Si12、Ti3Al、TiAl和TiAl3等物相组成。涂层中没有出现一般激光熔覆所产生的外延生长柱状晶组织, 全部为细小等轴晶。在800 ℃×24 h×5次循环氧化条件下, TC4基材单位面积的氧化增重约为35.1 mg·cm-2, 涂层的约为2.8 mg·cm-2和3.3 mg·cm-2。两种涂层的高温抗氧化性能较钛合金基材分别提高了12.5倍和10.6倍。激光熔覆原位自生Ti-Al-Si复合涂层能明显改善TC4钛合金的高温抗氧化性能。涂层抗氧化性改善的机理, 一方面是表面生成了连续致密的TiO2、Al2O3、SiO2氧化层, 阻碍了氧扩散; 另一方面是提高了氧化层的黏附性, 使氧化层不易从涂层表面剥落, 对涂层未氧化部分起到了很好的保护作用。

相较于蓝绿光长余辉材料, 近红光长余辉材料不仅种类少, 其性能也相对较差。本文探索基于余辉能量传递的机理, 实现将绿光长余辉材料SrAl2O4∶Eu2+,Dy3+的余辉能量传递给近红外光长余辉材料LiGa5O8∶Cr3+, 以此来增强LiGa5O8∶Cr3+的余辉性能。实验首先采用高温固相法分别合成SrAl2O4∶Eu2+,Dy3+和LiGa5O8∶Cr3+, 然后再按不同的质量比例混合均匀, 最后测试混合材料的余辉光谱性能。实验结果表明, 与SrAl2O4∶Eu2+,Dy3+混合后, 来自于LiGa5O8∶Cr3+的718 nm近红外余辉增强; 不同比例下混合后LiGa5O8∶Cr3+的余辉光谱增强效果不一, 其中两者比例为1∶1时, 能量传递效率最佳, LiGa5O8∶Cr3+的余辉最强。最后在监测LiGa5O8∶Cr3+的余辉718 nm的热释曲线中呈现了明显的SrAl2O4∶Eu2+,Dy3+的热释峰, 是两者之间存在能量传递的重要证据。该结果阐明了两种长余辉材料间余辉能量传递的可行性, 为改善近红外长余辉材料余辉性能提供了一种有潜力的方法。

This paper presents a surface plasmon resonance (SPR) imaging system based on angular modulation (AM) and intensity measurement (IM) together to avoid the mechanical errors of the angle scanning device. The SPR resonant angle was found by angular scanning method and then the light intensity changes were collected at a fixed incident angle. Glycerol gradient solution (0%, 1%, 2%, 3% (weight percentage) glycerol dissolved in water) experiments were conducted, which indicate that the best fixed angle location is the middle of the linear range of SPR absorption peak and the central area signals are more uniform than those of the border areas. The sensitivity differences of different areas of SPR images are studied, and an optimized algorithm is developed.

A facile surface plasmon resonance (SPR) chip is developed for small molecule determination and analysis. The SPR chip was prepared based on a self assembling principle, in which the modified bovine serum albumin (BSA) was directly self-assembled onto the bare gold surface. The surface morphology of the chip with the modified BSA was investigated by atomic force microscopy (AFM) and its optical properties were characterized. The surface binding capacity of the bare facile SPR chip with a uniform morphology is 8 times of that of the bare control SPR chip. Based on the experiments of immune reaction between cortisol antibody and cortisol derivative, the sensitivity of the facile SPR chip with the modified BSA is much higher than that of the control SPR chip with the un-modified BSA. The facile SPR chip has been successfully used to detect small molecules. The lowest detection limit is 5 ng/mL with a linear range of 5—100 ng/mL for cortisol analysis. The novel facile SPR chip can also be applied to detect other small molecules.

In this paper, a surface plasmon resonance imaging (SPRI) system for cell analysis is developed for obtaining the surface plasmon resonance (SPR) signal from the interactions between cells and different stimuli. The system is constructed with a red laser light source, a P-polarizer, a glass prism, a 5× objective lens, a charge coupled device (CCD) camera, a gold sensor chip, a polydimethylsiloxane (PDMS) reaction well and a mechanical scanning device. The system is applied to mapping living cells in response to stimuli by characterization of the refractive index (RI) changes. Cell responses to K⁺in KCl solutions with concentrations of 5 mmol/L, 20 mmol/L, 50 mmol/L and 100 mmol/L are collected, which indicates that the SPRI method can distinguish the concentration of the stimuli. Furthermore, cell responses to epidermal growth factor (EGF) and vascular endothelial growth factor (VEGF) are studied independently. The binding of EGF receptor (EGFR) and EGF is collected as the first signal, and the internal change in cells is recorded as the second signal. The cell response to VEGF is different from that to EGF, which indicates that the SPRI as a label-free, real-time, fast and quantitative method has a potential to distinguish the cell responses to different stimuli.

为了实现高阻值纳米薄膜材料的热电系数测量, 搭建了一套塞贝克系数测量系统。研究了该系统的温控精度和温差生成机制并测量了高阻值条件下微弱电压。首先, 建立了高真空度和带有多重电磁屏蔽的真空测试环境; 然后, 设计了高稳定度温差控制平台, 以便为测试样品提供可控温差; 同时根据高阻条件下的微弱电压的检测要求, 消除了检测通道的漏电流和分布电容的影响。最后, 提出了一种循环温差的测量方法, 用于有效去除分布电容引起的塞贝克电压长期漂移。采用该方法对高阻值的有机半导体材料进行了塞贝克系数的测定, 结果显示: 阻值高达7×1012Ω的有机薄膜材料的塞贝克系数的测量精密度<2%,温度控制精度为±0.001 K。得到的结果表明, 该系统能够实现对样品阻值高达1012Ω的纳米薄膜材料的塞贝克系数的测量。