气相沉积技术在制备高折射率光子晶体中的应用

采用激光全息光刻技术或激光直写技术制作微结构具有便捷、灵活、高效等优势,目前已成为研究制备光子晶体的一种有效方法.用全息光刻技术所制备的微结构的特点是单晶面积大(即内部结构缺陷较少)和可根据需要制作研究多种周期或准周期的晶格结构.但是所制备的结构由于感光树脂与空气的折射率比值较低,不能得到完全带隙光子晶体,从而使其应用受到局限性.以此树脂结构为模板,通过各种方法对其进行二次加工,制作高介电常数材料的反结构,近期已成为研究热点.本文介绍了气相沉积技术在制备高折射率光子晶体方面的应用和研究进展.     

负载型Fe－Co双金属催化剂的CO加氢反应性能研究及其原位FT－IR表征

负载于γ－Ａｌ_２Ｏ_３上的ＰＰＮ［ＦｅＣｏ_３（ＣＯ）_（１２）］簇合物作为催化剂前体，在ＣＯ加氢反应中显示出了较好的催化活性和对低碳烃的选择性。本文系统地考察了反应温度、反应时间、合成气比和气体空速对ＣＯ加氢反应，ＣＯ转化率和产物分布的影响。借助于ＩＣＰ分析、电镜和原位ＦＴ－ＩＲ跟踪技术，对负载型双金属簇催化剂的金属负载量、催化剂表面状态和脱羰过程中催化剂表面结构的变化进行了分析和表征，获得了一些有意义的结果。     

Probing Protein 3D Structures and Conformational Changes Using Electrochemistry-Assisted Isotope Labeling Cross-Linking Mass Spectrometry

This study presents a new chemical cross-linking mass spectrometry (MS) method in combination with electrochemistry and isotope labeling strategy for probing both protein three-dimensional (3D) structures and conformational changes. For the former purpose, the target protein/protein complex is cross-linked with equal mole of premixed light and heavy isotope labeled cross-linkers carrying electrochemically reducible disulfide bonds (i.e., DSP-d₀ and DSP-d₈ in this study, DSP = dithiobis[succinimidyl propionate]), digested and then electrochemically reduced followed with online MS analysis. Cross-links can be quickly identified because of their reduced intensities upon electrolysis and the presence of doublet isotopic peak characteristics. In addition, electroreduction converts cross-links into linear peptides, facilitating MS/MS analysis to gain increased information about their sequences and modification sites. For the latter purpose of probing protein conformational changes, an altered procedure is adopted, in which the protein in two different conformations is cross-linked using DSP-d₀ and DSP-d₈ separately, and then the two protein samples are mixed in 1:1 molar ratio. The merged sample is subjected to digestion and electrochemical mass spectrometric analysis. In such a comparative cross-linking experiment, cross-links could still be rapidly recognized based on their responses to electrolysis. More importantly, the ion intensity ratios of light and heavy isotope labeled cross-links reveal the conformational changes of the protein, as exemplified by examining the effect of Ca²⁺ on calmodulin conformation alternation. This new cross-linking MS method is fast and would have high value in structural biology.

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Solving nonlinear programming problems via a homotopy continuation method under three unbounded conditions

In this paper, we give three unbounded conditions under which we are able to solve the nonlinear programming problems in unbounded sets by a homotopy continuation method. In addition, we also discuss their relations.     

Individual eye model based on wavefront aberration

Based on the widely used Gullstrand-Le Grand eye model, the individual human eye model has been established here, which has individual corneal data, anterior chamber depth and the eyeball depth. Furthermore, the foremost thing is that the wavefront aberration calculated from the individual eye model is equal to the eye's wavefront aberration measured with the Hartmann-shack wavefront sensor. There are four main steps to build the model. Firstly, the corneal topography instrument was used to measure the corneal surfaces and depth. And in order to input cornea into the optical model, high-order aspheric surface-Zernike Fringe Sag surface was chosen to fit the corneal surfaces. Secondly, the Hartmann-shack wavefront sensor, which can offer the Zernike polynomials to describe the wavefront aberration, was built to measure the wavefront aberration of the eye. Thirdly, the eye's axial lengths among every part were measured with A-ultrasonic technology. Then the data were input into the optical design software–ZEMAX and the crystalline lens's shapes were optimized with the aberration as the merit function. The individual eye model, which has the same wavefront aberrations with the real eye, is established.     

Multifunctional TiO2‐Based Particles: The Effect of Fluorination Degree and Liquid Surface Tension on Wetting Behavior

A systematic investigation into the influence of the degree of fluorination on the static and dynamic wetting behavior of TiO₂‐based nanobelt (TNB) particles with various liquids is described. The effect of the degree of fluorination and the surface tension of the liquid on the occurrence and stability of liquid marbles, foams or dispersions are studied and the wetting behavior and arrangement of particles at the air–liquid surface are observed. Using contact angle (θ) measurements, the relation between the type of particle‐stabilized material and θ is established. For liquids of relatively high tension like water or formamide which do not wet the fluorinated particles, a powder‐like material (marble) is formed. For polar oils of intermediate tension (35–50 mN m^?1), which partially wet the fluorinated particles, stable air‐in‐oil foams can be prepared in which particles form a close‐packed layer enveloping air bubbles. Liquids of relatively low tension, e.g., ethanol or polydimethylsiloxane, wet the particles forming a uniform dispersion and partial sedimentation. By contrast, the as‐prepared hydrophilic TNB particles are rapidly wetted by all the liquids as expected due to their high surface energy. The stable cross‐stacked TNB particles with fluoroalkylsilane (FAS) modification could be a versatile platform in a wide range of applications, especially for fluidic devices (e.g., biofluids, gas sensing, and lab‐on‐a‐chip devices). In a proof‐of‐concept study, the oil–water separation performance of fabrics with chemically stable TNB/FAS coating and the liquid isolation by a TNB/FAS shell for highly sensitive gas sensing or reagent assays are investigated.     

用于头盔显示器的折/衍混合目镜设计

设计了一个用于头盔显示器的40°目镜,由两片镜组成,其中含有一个二元衍射面和一个非球面.该折/衍目镜具有10 mm的出瞳直径和25 mm的出瞳距离,结构紧凑,总重量仅为16.6 g.像差特性优于传统的折射目镜,轴上视场传递函数良好,适用于SXGA分辨率的显示.     

核科学中的世纪女杰

在20世纪的核物理领域中出现了四位令人瞩目的女科学家,除了我们所熟悉的居里夫人、吴键雄之外,还有奥地利物理学家丽丝·迈特纳和美国物理学家玛丽亚·梅耶.她们都堪称核科学中的巾帼英雄,对核科学的发展起了巨大的推动作用.     

Fabrication and direct bonding of photosensitive multicomponent silicate glasses for lossless planar waveguide splitters

In this paper the fabrication, characterization, and thermal assisted bonding of two photosensitive silicate glasses is presented, as part of a wider process aiming to obtain a planar waveguide lossless splitter for telecom applications. Two glass compositions are investigated: an Er–Yb doped silicate glass, which amplifies the signals when pumped at 980 μm and a matchable passive glass, which is designed to host the waveguide splitter. The two parts were bonded successfully using direct bonding technique at 605 ± 20 °C for 240 min under a pressure of 28 kPa. Vickers hardness measurements were made on the bulk glasses and at the bonded interface, which showed no cracks propagating along the interface.