Development of the Technique for Fabricating Submicron Moire Gratings on Metal Materials Using Focused Ion Beam Milling

A focused gallium ion （Ga＋） beam is used to fabricate micro/submicron spacing gratings on the surface of porous NiTi shape memory alloy （SMA ）. The crossing type of gratings with double-frequency （25001/mm and 50001/mm） using the focused ion beam （FIB） milling are successfully produced in a combination mode or superposition mode. Based on the double-frequency gratings, high-quality scanning electron microscopy （SEM） Moird patterns are obtained to study the micro-scale deformation of porous NiTi SMA. The grating fabrication technique is discussed in detail. The experimental results verify the feasibility of fabricating high frequency grating on metal surface using FIB milling.     

Fourier transform profilometry based on composite structured light pattern

In Fourier transform profilometry (FTP), the zero frequency of the imaged patterns will influence the measurement range and precision. The π phase shifting technique is usually used to eliminate the zero order component, but this method requires the capture of two fringe patterns with a π phase difference between them, which will impede the real time application of the method. In this paper, a novel method is proposed, in which a composite structured light pattern is projected onto the object. The composite structured light pattern is formed by modulating two separate fringe patterns with a π phase difference along the orthogonal direction of the two distinct carrier frequencies. This method can eliminate the zero frequency by using only one fringe pattern. Experiments show that there is no decrease in the precision of this novel method compared with the traditional π phase shifting technique.     

碳纳米管束中的正电子理论

采用中性原子叠加模型和有限差分方法(SNA-FD)计算了大范围内不同管径的单壁碳纳米管束中的正电子情况，发现对于单壁碳纳米管束，正电子的主要湮没区域，湮没对象和正电子寿命随碳纳米管管径的不同而发生规律性变化.计算得到管径范围在0.8—1.6nm的碳纳米管束的正电子寿命范围为332—470ps，与实验测得的394ps符合较好.     

Automated data reduction for hydrogen/deuterium exchange experiments,enabled by high-resolution fourier transform ion cyclotron resonance mass spectrometry

Mass analysis of proteolytic fragment peptides following hydrogen/deuterium exchange offers a general measure of solvent accessibility/hydrogen bonding (and thus conformation) of solution-phase proteins and their complexes. The primary problem in such mass analyses is reliable and rapid assignment of mass spectral peaks to the correct charge state and degree of deuteration of each fragment peptide, in the presence of substantial overlap between isotopic distributions of target peptides, autolysis products, and other interferant species. Here, we show that at sufficiently high mass resolving power (m/Δm_50% ≥ 100,000), it becomes possible to resolve enough of those overlaps so that automated data reduction becomes possible, based on the actual elemental composition of each peptide without the need to deconvolve isotopic distributions. We demonstrate automated, rapid, reliable assignment of peptide masses from H/D exchange experiments, based on electrospray ionization FT-ICR mass spectra from H/D exchange of solution-phase myoglobin. Combined with previously demonstrated automated data acquisition for such experiments, the present data reduction algorithm enhances automation (and thus expands generality and applicability) for high-resolution mass spectrometry-based analysis of H/D exchange of solution-phase proteins.     

用地面阵列寻找TeV能区γ点源的方法探讨

文中探讨搜寻TeV能区γ点源的方法.讨论利用student变量t判断来自源区及背景区宇宙线事例的统计差别,并由Bayes定理与MonteCarlo模拟相结合计算源区各能段的信号数,推算蟹状星云在TeV能区的γ射线微分能谱     

产物可用电喷雾质谱检测的氨基酸/肽季铵化新方法

氨基酸和肽中氨基的化学修饰反应,如乙酰化反应和烷基化反应已被广泛用于蛋白组学研究中蛋白质的定量分析．氨基酸和肽的季铵化产物具有独特的优点,在电喷雾质谱中具有很好的离子化效率,可大大提高检测的灵敏度．文献[6～8]报道的氨基酸和肽的季铵化方法均使用高浓度的盐(如KHCO3),严重影响了质谱的检测结果,难以直接用于蛋白质组学研究．     

共轭聚合物中均匀无序对极化子输运动力学的影响

基于扩展的Su-Schrieffer-Heeger紧束缚模型和非绝热动力学方法, 研究了共轭聚合物材料中均匀无序效应对极化子输运动力学的影响. 研究发现: 极化子的动力学输运过程由外加电场和均匀无序效应共同决定; 在大部分电场范围下, 均匀无序效应对极化子输运的影响不太明显, 几乎可以忽略; 但在弱电场下, 均匀无序效应不利于极化子输运. 与高斯型无序效应下极化子的输运过程相比, 具有均匀无序的薄膜形貌更有利于极化子输运.     

基于顺序注射分析法的丝网印刷型生物传感器系统的研究

采用顺序注射分析(SIA)与丝网印刷生物传感器联用法,考察辣根过氧化物酶(HRP)催化邻苯二胺(OPD)-H<,2>O<,2>反应体系.利用牛血清白蛋白(BSA)和戊二醛形成的交联大分子,将HRP固定于丝网印刷电极表面,制备成 HRP 电极,通过对缓冲液pH值及浓度、泵流速、样品量进行优化,建立用于检测HRP对H<,2...     

乳胶凝集法快速检测猪圆环病毒2型

发展了一种简单、快速、灵敏的乳胶凝集法用于猪圆环病毒2M的检测.合成了带有磺酸基的三元聚合物乳胶微球,通过静电相互作用,将猪圆环病毒2型单克隆抗体吸附到乳胶微球表面,形成乳胶抗体复合物诊断试剂.乳胶抗体复合物诊断试剂表面抗体与病毒表面抗原发生特异性反应,促使分散的乳胶微球凝集在一起,出现肉眼可见的凝集现象,而与去离子水...