Author Affiliations
Abstract
1 Institute for Quantum Science and Technology, College of Science, National University of Defense Technology, Changsha 410073, China
2 Hunan Key Laboratory of Mechanism and Technology of Quantum Information, Changsha 410073, China
3 School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, UK
The 3D location and dipole orientation of light emitters provide essential information in many biological, chemical, and physical systems. Simultaneous acquisition of both information types typically requires pupil engineering for 3D localization and dual-channel polarization splitting for orientation deduction. Here we report a geometric phase helical point spread function for simultaneously estimating the 3D position and dipole orientation of point emitters. It has a compact and simpler optical configuration compared to polarization-splitting techniques and yields achromatic phase modulation in contrast to pupil engineering based on dynamic phase, showing great potential for single-molecule orientation and localization microscopy.
PSF engineering geometric phase single-molecule orientation and localization microscopy Chinese Optics Letters
2024, 22(3): 031103
国家纳米科学中心中国科学院纳米生物效应与安全性重点实验室，北京 100190
超分辨显微成像技术自诞生以来，凭借其优异的纳米级空间分辨率，已成为生命科学研究中精准揭示复杂生命现象的重要成像技术。其中，基于单分子定位的超分辨成像策略，使得定位、观察、研究单个探针分子独特的理、化、光学性能成为可能。偏振作为荧光信号的一个重要特性，近年来伴随着单分子三维取向成像技术的发展，逐步在单分子成像和超分辨领域中展示出诸多新颖且重要的应用特性。本文总结了单分子三维取向超分辨成像技术的最新进展，介绍并分析了两类主要的单分子三维取向荧光显微技术——基于荧光吸收与辐射偏振调制的单分子三维取向成像方法以及利用点扩散函数工程将单个荧光分子的三维取向信息编码到荧光图像上的成像策略。此外，还探讨了应用于活细胞或单颗粒的其他类型的超分辨取向成像技术。最后，针对单分子三维取向超分辨成像技术发展与应用前景面临的挑战，进行了总结与展望。
显微 单分子荧光 超分辨成像 单分子空间取向 单分子定位显微术 激光与光电子学进展
2024, 61(6): 0618015
浙江大学光电科学与工程学院极端光学技术与仪器全国重点实验室，浙江 杭州 310027
生命体是由大量有机排列的分子组成的，其结构不仅与分子的位置分布有关，还与分子的排列方式和空间取向有关。偏振荧光显微成像技术利用荧光的偏振特性，能够对生物结构的分子取向进行观测和成像，进而从分子层面揭示生命活动的功能和代谢信息，有力推动了生物医学相关领域的研究和发展。本文从偏振荧光成像原理出发，对目前存在的多种偏振荧光显微成像技术进行原理介绍和现状分析，列举了其在生物医学领域的相关应用，讨论了其发展趋势及前景，旨在为该领域的科研人员了解偏振荧光显微成像技术提供参考。
偏振荧光显微 偏振调制 分子取向 空间角度传递 超分辨 激光与光电子学进展
2024, 61(6): 0618011
中北大学半导体与物理学院，山西 太原 030051
以推导的在生物组织中部分相干圆刃型位错光束传输时的交叉谱密度矩阵元，研究了传输中不同光束参数（光束波长λ、位错数目ndis、空间自相关长度σyy）对不同场点之间偏振特性的影响。部分相干圆刃型位错光束波长和位错数目不影响偏振态的初始值，而不同空间自相关长度的光束初始偏振态不同。随着传输距离增加，空间同一点的偏振态经历明显的起伏变化后最终趋于与源处一致，空间不同两点间的偏振态最终趋于一不同于初始值的定值。与远红外光和紫外光相比，可见光和近红外光更适合作为生物医学疾病诊疗的目标光束。位错数目越大，各偏振特征参量极值间距越大。空间自相关长度σyy与σxx的相对大小会影响偏振度的大小及变化趋势。
生物光学 圆刃型位错光束 偏振度 方位角 椭圆率 生物组织
湖南大学土木工程学院，绿色先进土木工程材料及应用技术湖南省重点实验室，长沙 41008湖南省绿色先进土木工程材料国际科技创新合作基地，长沙 410082
超高性能混凝土(UHPC)是一种具有超高强度、高韧性和优异耐久性的新型水泥基复合材料。由于它的水胶比低、细颗粒用量大，导致新拌浆体黏度高、纤维易成团、泵送困难等问题，不利于混凝土的匀质性及纤维对UHPC增强增韧作用的发挥。本文从流变表征和模型层面综述了UHPC的流变特性，基于水胶比、外加剂、矿物掺合料、纤维及骨料特性等因素对UHPC流变性能的影响，讨论分析了UHPC流变行为调控技术，包括调控水膜层厚度、调控浆膜层厚度、降低间隙液黏度、掺入黏度调节外加剂、改变纤维特性等5个方面及其调控作用机理。
超高性能混凝土 流变性能 调控技术 纤维分散与取向 力学性能 ultra-high performance concrete rheological property regulation techniques and mechanisms steel fiber dispersion and orientation mechanical properties
中国工程物理研究院 电子工程研究所绵阳 621999
应用电阻蒸发镀膜方法在钼基体表面沉积钛膜。采用X射线衍射仪（X-ray Diffraction，XRD）对钛膜的物相进行表征，获得钛膜的择优取向；采用扫描电镜（Scanning Electron Microscope，SEM）和原子力显微镜（Atomic Force Microscope，AFM）对钛膜的表面形貌进行表征，获得钛膜的晶粒尺寸分布情况及表面粗糙度；采用AFM纳米压痕技术对钛膜的力学性能进行表征，获得钛膜的弹性模量。结果表明：基体温度对钛膜的微观结构及力学性能有重要影响，在600~750 ℃范围内，随着基体温度的升高，钛膜晶粒取向的主要影响因素由应变能变为表面能，钛膜的择优取向由（101）变为（002）；基体温度的升高增强了基体表面钛原子的扩散能力，钛膜的平均晶粒尺寸、粗糙度及弹性模量均随基体温度的升高而增大。
基体温度 钛 择优取向 晶粒尺寸 纳米压痕 Substrate temperature Titanium Preferred orientation Grain size Nanoindentation
Author Affiliations
Abstract
1 Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, School of Electronic Science and Engineering, Xi’an, P. R. China
2 State Key Laboratory for Mechanical Manufacturing System, Xi’an Jiaotong University, Xi’an 710049, P. R. China
Lead-free piezoelectric sodium bismuth titanate (()TiO3, BNT) thin films were epitaxially grown onto (001)-, (110)-, and (111)-oriented Nb:SrTiO3 (STO) single crystal substrates prepared by sol–gel processing. Highly oriented growth in (001), (110), and (111) BNT thin films was obtained in this work benefiting from the lattice match between the BNT film and the STO substrate. The different growth models in thin films with various orientations result in various surface morphologies dependent on the film orientation. The piezoresponse of the BNT thin films was represented exhibiting a strong orientation dependence that (110)>(001)>(111). This is contributed by the various domain switching contribution related to the crystal symmetry and polarization distribution in the three oriented thin films.
Sodium bismuth titanate lead-free orientation dependence thin films piezoelectric properties Journal of Advanced Dielectrics
2023, 13(4): 2341003
Author Affiliations
Abstract
1 School of Chemistry & Chemical Engineering, Guangxi University, Nanning 530004, P. R. China
2 State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures, School of Resources, Environment and Materials, Guangxi University, Nanning 530004, P. R. China
Dielectric materials with high energy storage density () and efficiency () are expected for energy storage capacitors. In this work, 001-textured NbO3 (NBN) ceramics were prepared by a templated grain growth technique. The effects of microstructure and orientation degree on dielectric properties, polarization and energy storage performance were investigated. The textured ceramic with an optimized orientation degree (70%) showed a high of 2.4 J/cm3 and of 85.6%. The excellent energy storage properties of textured ceramic originate from the co-effect of interfacial polarization and clamping effect. The results indicate that texture development is a potential candidate to optimize the energy storage properties of functional ceramics.
NaNbO3 ceramics grain orientation energy storage density dielectric capacitors Journal of Advanced Dielectrics
2023, 13(4): 2341001
