基于OSLO的无限远像距消色差显微物镜的设计

共焦激光扫描显微镜对物镜有高分辨率、易于实现纵向扫描的要求,为此设计了高分辨率6片式无限远像距显微物镜.它的前置物镜与辅助物镜之间具有一段平行光路,因此容易实现轴向扫描.根据使用要求总体计算该物镜的外形尺寸,以像差理论为基础选择6片式的消色差物镜初始结构,用专业光学设计软件OSLO对物镜和辅助物镜进行设计和像质分析.设计结果显示,独特的6片式结构的20×物镜分辨率达到了800 lp/mm,符合共焦显微镜的使用要求.     

Donor-Acceptor Typed AIE Luminogens with Near-infrared Emission for Super-resolution Imaging

Aggregation-induced emission(AIE)luminogens(AIEgens)with high brightness in aggregates exhibit great potentials in biological imaging,but these AIEgens are seldom applied in super-resolution biological imaging,especially in the imaging by using the structural illumination microscope(SIM).Based on this consideration,we synthesized the donor-acceptor typed AIEgen of DTPA-BTN,which not only owns high brightness in the near-infrared(NIR)emission region from 600 nm to 1000 nm(photoluminescence quantum yield,PLQYs=11.35%),but also displays excellent photo-stability.In addition,AIE nanoparticles based on 4,7-ditriphenylamine-[1,2,5]-thiadiazolo[3,4-c]pyridine(DTPA-BTN)were also prepared with highly emissive features and excellent biocompatibility.Finally,the developed DTPA-BTN-based AIE nanoparticles were applied in the super-resolution cellular imaging via SIM,where much smaller full width at half-maximum values and high signal to noise ratios were obtained,indicating the superior imaging resolution.The results here imply that highly emissive AIEgens or AIE nanoparticles can be promising imaging agents for super-resolution imaging via SIM.     

基于扫描探针显微镜(SPM)的高密度信息存储

随着信息技术的飞速发展,高密度信息存储的研究成为国际上备受关注的研究领域。扫描探针显微技术（SPM）通过改变材料的光、电、磁等局域特性可以实现纳米尺度的信息存储,成为提高信息存储密度的最有效手段之一。本文从信息存储材料和技术角度综述了基于SPM的高密度信息存储最近的研究进展,并讨论了其将来的研究和发展方向。     

用透射电镜和火焰原子吸收法分析大气总悬浮颗粒物

以大气总悬浮颗粒物为主要研究对象,用透射电镜观察其形貌,污染特征明显;用火焰原子吸收法测定其水溶性常规元素K、Na、Ca和Mg。K、Na、Ca和Mg的检出限分别为0.105、0.124、0.259和0.237mg/kg,线性相关系数不低于0.9979,加标回收率为90.0%～95.0%,测定结果的相对标准偏差为0.6%～2.1%(n=6)。     

二氧化硅胶体晶体组装形貌研究

用原子力显微镜表征了二氧化硅胶体晶体的组装,探讨了二氧化硅微球用自然沉降法、抽滤法、溶剂挥发法组装时的组装行为,同时讨论了不同颗粒表面电位、不同溶剂介质及不同温度对其组装结果的影响。结果表明,颗粒表面电位是影响二氧化硅胶体晶体有序组装的重要因素之一。文中总结了最优的介质组成和温度条件,指出溶剂挥发法是较优的二氧化硅胶体晶体组装方法,其方法操作简单、周期短、得到的胶态晶体质量高,能在较大面积内高度有序。     

溶剂对反胶束法合成CdS纳米粒子粒径的影响

以磺基琥珀酸二辛酯钠盐(AOT)为保护剂,利用反胶束法在不同烷烃溶液中合成了CdS纳米粒子.采用紫外-可见光谱、透射电子显微镜、荧光光谱法对其进行表征.研究表明:在不同烷烃溶液中合成的CdS纳米粒子,其粒子大小和荧光强度都随溶剂而改变.     

Studies of heterogeneity properties of selected high-temperature superconductor surfaces

Nitrogen adsorption measured at 77 K was used to characterize the surface heterogeneity of high-temperature superconductor surfaces. Properties relating to adsorption and porosity of the solids (adsorption capacity, specific surface area, radii and volume of the pores, pore-size distribution function) were determined from nitrogen adsorption–desorption isotherms and atomic force microscopy (AFM) for a series of oxide superconductors. It is shown that the adsorption isotherms of all samples are S-shaped and belong to type II according to the IUPAC classification. On the basis of the nitrogen adsorption isotherms and AFM data, fractal dimensions were determined and correlations found with adsorption and porosity parameters.     

MORPHOLOGICAL OBSERVATION OF SINGLE-CHAIN POLY (METHYL METHACRYLATE) PARTICLES*

Tapping mode atomic force microscope has been applied to observe single-chain PMMAparticles which were stored for six months at room temperature after sprayed from verydilute solutions in good solvents, good/poor mixed solvents, and a theta solvent. Monodis-perse PMMA standards of molecular weights ranging from 7.90×10~4 to 1.3×10~6 wereused to investigate the effect of molecular weight oh the size of the single-chain PMMAparticles. These single-chain particles showed close to spherical shapes. The morphologyof single-chain PMMA particles of a given molecular weight was found to be identical inspite of different solvents used for solution spraying. Molecular weigh dependence of theparticle dimension was also found. The diameters of single-chain PMMA particles aftercorrection of tlp-geometry effect were compared to the values estimated from molecularweight and density.     

Metal-to-Oxide Charge Transfer Observed by a Kelvin Probe Force Microscope

The charge transfer from a nanometer-sized transition metal particle to a catalyst support is thought to affect reactions over the metal surface. We propose the application of Kelvin probe force microscope, which is an extension of the atomic force microscope, to observe the charge transfer particle-by-particle. Our recent results on Na adatoms, Cl adatoms, Pt adatoms and particles, and Ni particles evaporated on TiO₂(110) are reviewed.     

A technique for production of nanocrystalline cellulose with a narrow size distribution

Nanocrystalline cellulose (NCC) was prepared by sulfuric acid hydrolysis of microcrystalline cellulose. A differential centrifugation technique was studied to obtain NCC whiskers with a narrow size distribution. It was shown that the volume of NCC in different fractions had an inverse relationship with relative centrifugal force (RCF). The length of NCC whiskers was also fractionized by differential RCF. The aspect ratio of NCC in different fractions had a relatively narrow range. This technique provides an easy way of producing NCC whiskers with a narrow size distribution.