CO_2激光光栅式扫描修复熔石英表面缺陷的实验研究与数值模拟

基于熔石英材料对波长为10.6μm的CO2激光具有强吸收作用这一特点,提出采用CO2激光光栅式多次扫描修复熔石英光学元件表面密集分布的划痕和抛光点等缺陷的方法.实验结果表明,在合理的扫描参数下,元件表面的划痕和抛光点等缺陷可被充分地消除.损伤阈值测试结果表明,表面划痕和抛光点等缺陷被完全消除的元件的损伤阈值可回复到或超过基底的损伤阈值.同时结合有限元软件Ansys的模拟结果分析了CO2激光扫描修复及消除元件表面划痕和抛光点等缺陷的过程.本文为消除元件表面划痕和抛光点等缺陷提供了非常有意义的参考.     

Z箍缩Al等离子体X辐射谱线的分离及电子温度的提取

以"强光一号"Z箍缩装置10174发次光谱诊断实验结果为例,描述了一种对Z箍缩等离子体X辐射光谱分离提纯、诊断的方法.对连续辐射谱和特征辐射线谱进行分离,并从连续辐射谱和特征辐射线谱中提取了等离子体电子温度信息.结果显示:等离子体连续谱主要由等离子体中心的高温区(Te=290.7 eV±1.2 eV)和温度较低的壳层区域(Te=95.3 eV±8.3 eV)两部分叠加而成;特征辐射线谱主要反映了等离子体中心的高温区信息,根据非局域热动平衡模型计算提取的电子温度约为299—313 eV,与连续谱诊断结果基本符合.     

Time-Resolved Fluorescence Anisotropy Study of the Interaction Between DNA and a Peptide Truncated from the p53 Protein Core Domain

Time-resolved fluorescence anisotropy spectroscopy was applied to study the interaction between a peptide truncated from the binding site of tumor suppressor p53 protein and the DNAs covalently labeled with 6-carboxyfluorescein (FAM) dye. Fluorescence intensity quenching and changes of anisotropy decay lifetime were monitored when FAM labeled DNA formed complex with the peptide. The results demonstrated that the sequence of DNA could not define the binding specificity between the peptide and DNA. But the anisotropy decay of FAM can be used to examine the binding affinity of the peptide to DNA. The fluorescent dynamics of FAM can also be used to represent the rigidity of the complex formed between the peptide and DNA.     

Graphene/LiNbO3 surface acoustic wave device based relative humidity sensor

This study described relative humidity (RH) sensing using a graphene/128° YX LiNbO₃ surface acoustic wave (SAW) device. The resonant frequency of the device decreased in a two-stage manner as the RH increased. For a low RH range (RH < 50%), a frequency downshift of 1.38 kHz per 1% RH change was observed. This was attributed to mass loading of the SAW propagation surface due to the adsorption of water molecules by the graphene surface. For a high RH range (RH > 50%), a frequency downshift of 2.6 kHz per 1% RH change was obtained, which was due to the change in elastic grapheme properties. The mass loading effect of the water layer was less effective at high temperature, resulting in a lower temperature coefficient of resonant frequency (TCF).     

Sputtered ZnO film on aluminium foils for flexible ultrasonic transducers

Nanocrystalline ZnO films with both C-axis vertical grown and inclined angled grown were sputter-deposited onto aluminium foils (50 μm thick) and characterised for using as flexible ultrasonic transducers. As-deposited C-axis grown ZnO films were annealed at different temperatures up to 600 °C to enhance film crystallinity and reduce film stress. The C-axis grown ZnO film on the Al foil were bonded onto steel plates, and the pulse-echo tests verified a good performance (with dominant longitudinal waves) of the ultrasonic transducers made from both as-deposited and post-annealed films. Inclined angled ZnO films on the Al foil glued onto steel plates generated mixed shear and longitudinal waves in the pulse-echo test.     

Fe—C—Cr—Mn亚稳奥氏体铸铁磨损表层的TEM观察

用透射电镜观察了 Fe- C- Cr- Mn亚稳奥氏体基铸铁在 80 0 #Si C砂纸上经往复摩擦磨损试验后磨损表层的微观结构 .结果表明 :摩擦表层奥氏体基体的微观组织结构不均匀 ,有位错区、层错区、滑移区和ε-马氏体区 ;此外 ,还观察到了大量的奥氏体变体 ,沿其 [1 31 ]晶带轴旋转 2 5.35°可与基体 [1 1 2 ]晶带轴重合 ;在碳化物颗粒附近只观察到奥氏体变体和层错 .     

退化时滞微分系统解的指数估计

为了更深入地研究退化时滞微分系统,本文应用算子理论和Gronwall引量等,讨论了其解的指数估计问题,并给出指数估计的表达式。     

A Study of the Probe Effect on the Apparent Image of Biological Atomic Force Microscopy

The atomic force microscopy (AFM) possesses high spatial resolution and it is compatible with liquid environments. AFM can provide possibility to study a wide range of biological problems at the molecular level and acquire topological information at nanometre resolution under physiological conditions1,2. However, a major problem for image reconstruction of biological specimens is that structures of most biological molecules are very soft and delicate, which could be easily deformed and dama…     

聚乙烯的表面光接枝改性研究进展

综述了紫外光引发接枝改性聚乙烯表面的研究进展,包括光接枝聚合机理,改性方法,接枝链的结构和形态,影响因素等。     

镧对红壤硝化、磷转化和酚分解作用的影响

通过室内培养和盆栽试验研究了La对红壤硝化作用,磷转化作用和酚分解作用的影响,低浓度下,La对土壤的硝化作用和磷转化作用均有某些刺激作用,但随着浓度的升高产生抑制作用并不断增加,La对土壤酚分解作用表现为剧烈的抑制作用,并随着浓度的升高,抑制作用不断增强,随着培养时间的延长,La对土壤硝化作用和酚分解作用的抑制作用有降低的趋势。