生物样品的软X射线显微成象

软X射线显微术最适合于自然状态下生物样品的高分辨率成象。在过去十年中软X射线显微成象技术在世界范围内得到了迅速的发展。本文扼要地讨论了软X射线显微成象的衬度机制和高分辨率X射线光学的基本原理,并且综述介绍各种软X射线显微成象方法以及它的发展和前景。     

生物样品的软X射线显微成象

软X射线显微术最适合于自然状态下生物样品的高分辨率成象。在过去十年中软X射线显微成象技术在世界范围内得到了迅速的发展。本文扼要地讨论了软X射线显微成象的衬度机制和高分辨率X射线光学的基本原理,并且综述介绍各种软X射线显微成象方法以及它的发展和前景。     

软X射线显微成像位相型波带片浅析

软X射线显微成像技术是研究超微观世界的有力工具,而位相型波带片则以其高分辨率的优势,目前已成为实现软X射线成像的理想光学元件.本文简要介绍位相型波带片的特性及其在软X射线显微成像技术中的应用.     

软X射线显微术

一、引 言 X射线作为一种显微工具已研究多年,且早有介绍[1].但以前的研究大多使用波长在0.1-1nm的较硬的X射线,这主要是受到X射线光源的限制.硬X射线与物质作用比较复杂,不利于得到好的衬度.七十年代以来,同步辐射光源的发展,提供了具有高强度的连续可调波长的软X射线光源.软X射线显微术(波长范围大约在 1—10 nm)具有电子显微术所不具备的优点,尤其是在研究生物物质(特别是活的物质)及轻元素方面.因此,近年来X射线显微术的研究重新活跃起来,而且软X射线光学也有了新的发展.现在使用软X射线光学直接成像的分辨率已经超过光学显微镜的分…     

同步辐射讲座 第三讲 软X射线显微术

对生物样品的研究，软X射线显微术具有独特的优势，例如，它能够对较厚的活性含水的生物样品直接进行显微成像以及元素分布的微区分析等，文章简要论述了软X射线显微术的衬度机制及其优势；列表概括了包括SCXM，TXM，STXM，Gabor全息以及衍射等几种类型的X射线显微术的基本特性；简要综述了合肥国家同步辐射实验室（NSRL）软X射线显微术的研究进展。     

激光等离子体光源软X射线反射率计

介绍了所研制的激光等离子体光源软X射线反射率计,该反射率计由激光等离子体光源、掠入射光栅单色仪、样品室、真空系统、样品台、光电探测系统和计算机控制系统组成,工作波段8～30 nm,测量样品的最大尺寸为130 mm×120 mm×120 mm(长×宽×高),可以利用这台反射率计对软X射线波段光栅、滤光片和多层膜反射镜等光学元件进行测量和评估。为检验反射率计的性能指标,利用该反射率计对本室研制的软X射线多层膜反射镜的反射率进行了测量,测量结果与理论计算结果符合较好,反射率测量重复性为±0.6%。     

软x射线近贴显微技术

软x射线近贴显微技术不但可使活的生物样品成象,分辨率高于光学显微镜,而且人为的样品准备程序在该技术中都可避免。本文描述了用高功率激光打靶产生的等离子体作为软x射线源而进行的近贴显微研究,并得到了分辨率好于1μm的结果。     

高分辨率软X射线显微成像原理及其应用

软X射线显微成像具有分辨率高、辐射损伤小以及能够对含水的生物样品直接进行显微成像等独特的优势,目前已成为研究生命科学和生物学等学科中的超微观世界的特殊工具.本文简要介绍基于波带片的高分辨率软X射线显微成像的原理及其应用.     

软X射线相位型聚焦波带片的研制

软X射线波带片是软X射线光学中聚焦、色散和成像的重要元件。以激光全息-离子束刻蚀技术制作金的振幅型软X射线聚焦波带片,以此为掩模,利用接触式同步辐射光刻和离子束刻蚀技术在聚酰亚胺衬底上,分别制作出了镍和锗的软X射线相位型聚焦波带片。     

软 X射线光学表面散射检测

应用自行研制的软X射线反射率计,分别对不同的反射镜样品,在不同的工作波段以及掠射角下研究了软X射线波段掠入射光学表面的散射。实验结果表明：掠射角增加,波长减小,粗糙度增加,软X射线掠入射表面散射程度加重。     

溶剂对Bi2WO6形貌及其γ射线屏蔽性能的影响

通过简单的溶剂热法,在不添加任何表面活性剂的情况下,系统地研究吡啶、甘露醇、聚乙二醇和乙二醇四种溶剂对Bi2WO6辐射防护材料的影响。并利用XRD,SEM,TEM,HRTEM和DRS等分析技术对Bi2WO6晶体的组成、形貌、比表面积和禁带宽度等进行了表征。实验结果表明,溶剂对防护材料的形貌、光致发光性能和辐射防护性能有较大影响。选用吡啶作为溶剂,有利于材料形成不规则纳米球,提高其结晶度、光致发光强度及射线屏蔽率。该形貌下PS/Bi2WO6材料对155Eu和22Na混合点源的105.310 keV的射线屏蔽率达54.17%,已高于传统防护材料PbWO4。     

Preparation and characterization of nontoxic magnetic-luminescent nanoprobe

A novel nontoxic,magnetic,and luminescent nanoprobe is prepared by using complex nanoparticles,which are composed of Fe3O4 nanoparticles and Mn-doped ZnS quantum dots(QDs).The nanocomposite probe can provide visible optical and magnetic resonance images simultaneously.Compared with the previously toxic cadmium and mercury based QDs,the superiority of the Mn-doped ZnS QDs is little virulence.The structure and the properties of the particles are characterized by energy dispersive X-ray analysis spectroscopy,X-ray photoelectron spectroscopy,transmission electron microscopy,photoluminescence spectroscopy,and vibrating sample magnetometer.     

Biological mineralization of iron: Studies using Mössbauer spectroscopy and complementary techniques

Biological deposition of solid Fe-containing phases can be studied using⁵⁷Fe Mössbauer spectroscopy. Other techniques are needed in order to understand this complex process. These include proton-induced X-ray and -ray emission (PIXE/PIGME), electron microscopy, electron and X-ray diffraction, infrared spectroscopy and chemical characterization of organic components. This paper reviews and evaluates the application of these techniques to biological mineralization of Fe, particularly that occurring in the radula teeth of the marine molluscs, chitons and limpets.     

Biological soft X‐ray tomography on beamline 2.1 at the Advanced Light Source

Beamline 2.1 (XM‐2) is a transmission soft X‐ray microscope in sector 2 of the Advanced Light Source at Lawrence Berkeley National Laboratory. XM‐2 was designed, built and is now operated by the National Center for X‐ray Tomography as a National Institutes of Health Biomedical Technology Research Resource. XM‐2 is equipped with a cryogenic rotation stage to enable tomographic data collection from cryo‐preserved cells, including large mammalian cells. During data collection the specimen is illuminated with `water window' X‐rays (284–543 eV). Illuminating photons are attenuated an order of magnitude more strongly by biomolecules than by water. Consequently, differences in molecular composition generate quantitative contrast in images of the specimen. Soft X‐ray tomography is an information‐rich three‐dimensional imaging method that can be applied either as a standalone technique or as a component modality in correlative imaging studies.     

激光软X—射线近贴显微技术初步研究

描述了用高功率脉冲激光打靶产生的等离子体作为软X-射线源而进行的近贴显微研究,并得到了分辨率好于1μm的结果.     

Morphology of Tungsten Nanooxides,Synthesized by Laser Ablation of Metal in Water

Colloidal solution precipitates obtained during laser ablation of tungsten in water and containing nanostructured metal oxides are studied using X-ray diffraction and scanning electron microscopy. The nanostructure composition and morphology are analyzed. It is shown that the material composing nanostructures is X-ray amorphous, i.e., the particle size does not exceed 1–2 nm. The high degree of the structure surface development implies prospects of their use as substrata when analyzing the composition of various materials by surface-enhanced Raman scattering.     

Deposition of iron pyrite via pulsed electron ablation

Pulsed electron beam ablation is a relatively novel deposition technique with some unique advantages, such as ease for scale-up and low operating cost. In this work, we report on the preparation of iron pyrite (FeS₂) on 1.5-cm² glass substrates through the pulsed electron beam ablation of a single synthetic target. The 40–120-nm-thin films were deposited at a substrate temperature ranging from room temperature to 250 ^°C and under a background argon atmosphere of 3.5 mTorr. Different characterization techniques have been used to analyze the deposited films, such as grazing-angle x-ray diffraction (XRD), X-ray photon spectroscopy (XPS), visible Raman spectroscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), and visible optical reflectance spectroscopy. The findings show that iron pyrite can be obtained at high temperature in association with other phases.