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Aggregate 2022年第5期3卷 217-226页

作者： Gianluigi Albano Marcin Gorecki Tamas Javorfi Rohanah Hussain Giuliano Siligardi Gennaro Pescitelli Lorenzo Di Bari Dipartimento di Chimica e Chimica Industriale Universitàdi PisaPisaItaly Institute of Organic Chemistry Polish Academy of SciencesWarsawPoland diamond light source Ltd.ChiltonUK Dipartimento di Chimica Universita degli Studi di Bari‘Aldo Moro’via Edoardo Orabona 4Bari 70126Italy

The study of the chiroptical properties of thin-film samples of two chiral benzo[1,2-b:4,5-b’]dithiophene-based oligothiophenes with optoelectronic properties was carried out at diamond B23 beamline using the synchrotron radiation electronic circular dichroism imaging(SR-ECDi)*** experimental results support the hypothesis that the non-reciprocal circularly polarized absorption observed in these materials is due to the combined linear dichroism and linear birefringence *** mapping at 50-μM spatial resolution revealed that several species coexist in the mesoscopic chiral domains likely due to different aggregated phases,which were identified in the films by SR-ECDi but could not be detected with benchtop ECD instruments.

关键词： benzo[1,2-b:4,5-b’]dithiophene circular dichroism imaging oligothiophenes synchrotron radiation thin films

Synchrotron Characterisation of Ultra-Fine Grain TiB_(2)/Al-Cu Composite Fabricated by Laser Powder Bed Fusion

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Acta Metallurgica Sinica(English Letters) 2022年第1期35卷 78-92页

作者： Sheng Li Biao Cai Ranxi Duan Lei Tang Zihan Song Dominic White Oxana V.Magdysyuk Moataz M.Attallah School of Metallurgy and Materials University of BirminghamEdgbastonBirminghamB152TTUK Department of Materials Science and Engineering Southern University of Science and TechnologyShenzhen518055China ZEISS House Building 1030Cambourne Business ParkCambourneCambridgeCB236DWUK diamond light source Ltd Harwell Science and Innovation CampusDidcotOX110DEOxfordshireUK

Isotropy in microstructure and mechanical properties remains a challenge for laser powder bed fusion(LPBF)processed materials due to the epitaxial growth and rapid cooling in *** this study,a high-strength TiB_(2)/Al-Cu composite with random texture was successfully fabricated by laser powder bed fusion(LPBF)using pre-doped TiB_(2)/Al-Cu composite powder.A series of advanced characterisation techniques,including synchrotron X-ray tomography,correlative focussed ion beam-scanning electron microscopy(FIB-SEM),scanning transmission electron microscopy(STEM),and synchrotron in situ X-ray diffraction,were applied to investigate the defects and microstructure of the as-fabricated TiB_(2)/Al-Cu composite across multiple length *** study showed ultra-fine grains with an average grain size of about 0.86μm,and a random texture was formed in the as-fabricated condition due to rapid solidification and the TiB_(2)particles promoting heterogeneous *** yield strength and total elongation of the as-fabricated composite were 317 MPa and 10%,*** contributions of fine grains,solid solutions,dislocations,particles,and Guinier-Preston(GP)zones were *** was found to be initiated from the largest lack-of-fusion pore,as revealed by in situ synchrotron tomography during tensile *** situ synchrotron diffraction was used to characterise the lattice strain evolution during tensile loading,providing important data for the development of crystal-plasticity models.

关键词： Aluminium metal matrix composite Laser powder bed fusion Heterogeneous nucleation Synchrotron characterisation

Methanol oxidation over shell-core MOx/Fe2O3（M = Mo, V, Nb） catalysts

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Chinese Journal of Catalysis 2019年第11期40卷 1686-1692页

作者： Pip Hellier Peter P. Wells Michael Bowker UK Catalysis Hub Research Complex at Harwell Rutherford Appleton Laboratory Harwell UK School of Chemistry Cardiff University Cardiff UK School of Chemistry University of Southampton Southampton UK diamond light source Ltd Harwell Science and Innovation Campus Didcot UK

We present a comparison of Mo, V and Nb oxides as shell materials atop haematite cores used for selective methanol oxidation. While Mo and V both yield high selectivity to formaldehyde, Nb does not. Very different reactivity patterns are seen for Nb, which mainly shows dehydrogenation (to CO) and dehydration (to DME), indicating the lack of a complete shell, while Raman spectroscopy shows that the Mo and V formation process is not followed by NbOx. We suggest this is due to the large differences in mobility within the solid materials during formation, NbOx requiring significantly higher (and deleterious) calcination temperatures to allow sufficient mobility for shell completion.

关键词： Methanol Oxidation Formaldehyde Iron molybdate Shell-core catalyst

Optimization for epitaxial fabrication of infinite-layer nickelate superconductors

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Frontiers of physics 2024年第3期19卷 61-69页

作者： Minghui Xu Yan Zhao Xiang Ding Huaqian Leng Shu Zhang Jie Gong Haiyan Xiao Xiaotao Zu Huiqian Luo Ke-Jin Zhou Bing Huang Liang Qiao School of Physics University of Electronic Science and Technology of ChinaChengdu 610054China Beijing Computational Science Research Center Beijing 100193China diamond light source Harwell CampusDidcot OX110DEUnited Kingdom Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China Songshan Lake Materials Laboratory Dongguan 523808China

The discovery of nickelates superconductor creates exciting opportunities to unconventional superconductivity. However, its synthesis is challenging and only a few groups worldwide can obtain samples with zero-resistance. This problem becomes the major barrier for this field. From plume dynamics perspective, we found the synthesis of superconducting nickelates is a complex process and the challenge is twofold, i.e., how to stabilize an ideal infinite-layer structure Nd_(0.8)Sr_(0.2)NiO_(2), and then how to make Nd_(0.8)Sr_(0.2)NiO_(2) superconducting? The competition between perovskite Nd_(0.8)Sr_(0.2)NiO_(3) and Ruddlesden−Popper defect phase is crucial for obtaining infinite-layer structure. Due to inequivalent angular distributions of condensate during laser ablation, the laser energy density is critical to obtain phase-pure Nd_(0.8)Sr_(0.2)NiO_(3). However, for obtaining superconductivity, both laser energy density and substrate temperature are very important. We also demonstrate the superconducting Nd_(0.8)Sr_(0.2)NiO_(2) epitaxial film is very stable in ambient conditions up to 512 days. Our results provide important insights for fabrication of superconducting infinite-layer nickelates towards future device applications.

关键词： nickelate superconductivity infinite-layer plasma condensate plume dynamics

Cortisol facilitates the immune escape of human acute myeloid leukemia cells by inducing latrophilin 1 expression

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Cellular & Molecular Immunology 2018年第11期15卷 994-997页

作者： Svetlana S.Sakhnevych Inna M.Yasinska Alison M.Bratt Ouafa Benlaouer Isabel Gonçalves Silva Rohanah Hussain Giuliano Siligardi Walter Fiedler Jasmin Wellbrock Bernhard F.Gibbs Yuri A.Ushkaryov Vadim V.Sumbayev Medway School of Pharmacy Universities of Kent and GreenwichChatham MaritimeUK Beamline B23 Diamond Light SourceDidcotUK Department of Oncology Hematology and Bone Marrow Transplantation with Section PneumologyHubertus Wald University Cancer CenterUniversity Medical Center Hamburg-EppendorfHamburgGermany Department of Medicine Dermatology and AllergologyUniversity of OldenburgOldenburgGermany

The progression of acute myeloid leukemia(AML)—the most severe blood/bone marrow cancer—is determined by the ability of malignant cells to escape host immune ***,the systemic regulatory mechanisms underlying this phenomenon remain largely *** this study,we discovered a fundamental systemic biochemical strategy that allows AML cells to employ physiological systems within the body to survive and escape immune *** found that AML cells use a crucial human adrenal cortex hormone(cortisol)to induce the expression of neuronal receptor latrophilin 1(LPHN1),which facilitates *** receptor interacts with the blood plasma protein fibronectin leucine rich transmembrane protein 3(FLRT3)to cause secretion of the immune suppressor galectin-9,which impairs the anticancer activities of cytotoxic lymphoid cells.

关键词： acute myeloid cortex

4^(th) generation synchrotron source boosts crystalline imaging at the nanoscale

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light(Science & Applications) 2022年第4期11卷 662-673页

作者： Peng Li Marc Allain Tilman A.Grunewald Marcus Rommel Andrea Campos Dina Carbone Virginie Chamard Aix-Marseille Univ CNRSCentrale MarseilleInstitut FresnelMarseilleFrance Nanofabrication Laboratory Department of Microtechnology and NanoscienceMC2Chalmers University of TechnologySE-41296 GothenburgSweden Aix Marseille Univ CNRSCentrale MarseilleFSCM(FR1739)CP2M13397 MarseilleFrance. MAX IV Laboratory Fotongatan 222594 LundSweden Present address:diamond light source Harwell Science and Innovation CampusFermi AveDidcot OX110DEUK

New 4^(th)-generation synchrotron sources,with their increased bilince,promise to greatly improve the performances of coherent X-ray *** perspective is of major interest for crystal microscopy,which aims at revealing the 3D crystalline structure of matter at the nanoscale,an approach strongly limited by the available coherent *** results,based on Bragg ptychography experiments performed at the frst 4-generation synchrotron source,demonstrate the possibility of retrieving a high-quality image of the crystalline sample,with unprecedented ***,the larger available coherent flux produces datasets with enough information to overcome experimental limitations,such as strongly deteriorated scanning *** show this achievement would not be posible with 30-generation sources,a limit that has inhibited the development of this otherwise powerful microscopy method,so ***,the advent of next-generation synchrotron sources not only makes Bragg ptychography suitable for high throughput studies but also strongly relaxes the associated experimental constraints,making it compatible with a wider range of experimental set-ups at the new synchrotrons.

关键词： crystalline coherent source

Evaluating the morphology of the degradation layer of pure magnesium via 3D imaging at resolutions below 40 nm

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Bioactive Materials 2021年第12期6卷 4368-4376页

作者： Berit Zeller-Plumhoff Daniel Laipple Hanna Slominska Kamila Iskhakova Elena Longo Alexander Hermann Silja Flenner Imke Greving Malte Storm Regine Willumeit-Romer Helmholtz-Zentrum hereon GmbH Institute of Metallic BiomaterialsMax-Planck-Straße 121502GeesthachtGermany Helmholtz-Zentrum hereon GmbH Research ReactorMax-Planck-Straße 121502GeesthachtGermany Helmholtz-Zentrum hereon GmbH Institute of Materials PhysicsMax-Planck-Straße 121502GeesthachtGermany Helmholtz-Zentrum hereon GmbH Institute of Materials Systems ModellingMax-Planck-Straße 121502GeesthachtGermany diamond light source Ltd. Diamond HouseHarwell Science and Innovation CampusDidcotOX110DEUnited Kingdom

Magnesium is attractive for the application as a temporary bone implant due to its inherent biodegradability,non-toxicity and suitable mechanical *** degradation process of magnesium in physiological environments is complex and is thought to be a diffusion-limited transport *** use a multi-scale imaging approach using micro computed tomography and transmission X-ray microscopy(TXM)at resolutions below 40 ***,we are able to evaluate the nanoporosity of the degradation layer and infer its impact on the degradation process of pure magnesium in two physiological *** samples were degraded in simulated body fluid(SBF)or Dulbecco’s modified Eagle’s medium(DMEM)with 10%fetal bovine serum(FBS)for one to four *** reveals the three-dimensional interconnected pore network within the degradation layer for both *** pore network morphology and degradation layer composition are similar for all *** contrast,the degradation layer thickness in samples degraded in SBF was significantly higher and more inhomogeneous than in DMEM+10%*** features could be observed within the degradation layer of samples degraded in SBF,suggesting the formation of microgalvanic cells,which are not present in samples degraded in DMEM+10%*** results suggest that the nanoporosity of the degradation layer and the resulting ion diffusion processes therein have a limited influence on the overall degradation *** indicates that the influence of organic components on the dampening of the degradation rate by the suppression of microgalvanic degradation is much greater in the present study.

关键词： Magnesium degradation Porosity Transmission X-ray microscopy 3D imaging

nNPipe: a neural network pipeline for automated analysis of morphologically diverse catalyst systems

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npj Computational Materials 2023年第1期9卷 2176-2187页

作者： Kevin P.Treder Chen Huang Cameron G.Bell Thomas J.A.Slater Manfred E.Schuster DoğanÖzkaya Judy S.Kim Angus I.Kirkland Department of Materials University of OxfordParks RoadOX13PH OxfordOxfordshireUnited Kingdom Rosalind Franklin Institute Harwell Research CampusOX110FA DidcotOxfordshireUnited Kingdom School of Chemistry The University of EdinburghEH93FJ EdinburghUnited Kingdom School of Chemistry Cardiff UniversityPark PlaceCF103AT CardiffUnited Kingdom Electron Physical Sciences Imaging Centre Diamond Light SourceOxfordshire OX110DEUnited Kingdom Johnson Matthey Technology Centre Blount’s CourtSonning CommonReading RG49NHUnited Kingdom

We describe nNPipe for the automated analysis of morphologically diverse catalyst materials. Automated imaging routines anddirect-electron detectors have enabled the collection of large data stacks over a wide range of sample positions at high temporalresolution. Simultaneously, traditional image analysis approaches are slow and hence unsuitable for large data stacks andconsequently, researchers have progressively turned towards machine learning and deep learning approaches. Previous studiesoften detail work on morphologically uniform material systems with clearly discernible features, limited workable image sizes andtraining data that may be biased due to manual labelling. The nNPipe data-processing method consists of two standaloneconvolutional neural networks that were exclusively trained on multislice image simulations and enables fast analysis of2048 × 2048 pixel images. Inference performance compared between idealised and real industrial catalytic samples and insightsderived from subsequent data analysis are placed into the context of an automated imaging scenario.

关键词： catalyst hence subsequent

Ptycho-endoscopy on a lensless ultrathin fiber bundle tip

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light(Science & Applications) 2024年第9期13卷 1766-1778页

作者： Pengming Song Ruihai Wang Lars Loetgering Jia Liu Peter Vouras Yujin Lee Shaowei Jiang Bin Feng Andrew Maiden Changhuei Yang Guoan Zheng Department of Biomedical Engineering University of ConnecticutStorrsCT 06269USA CarlZeiss AG Carl Zeiss PromenadeJenaThuringia 07745Germany United States Department of Defense WashingtonDC 20301USA School of Electrical and Electronic Engineering Yonsei UniversitySeoul 03722Republic of Korea Department of Electronic and Electrical Engineering University of SheffieldSheffield South Yorkshire S13JDUK diamond light source HarwellOxfordshire OX110DEUK Department of Electrical Engineering California Institute of TechnologyPasadenaCA 91125USA Center for Biomedical and Bioengineering Innovation University of ConnecticutStorrsCT 06269USA

Synthetic aperture radar(SAR)utilizes an aircraft-carried antenna to emit electromagnetic pulses and detect the returning *** the aircraft travels across a designated area,it synthesizes a large virtual aperture to improve image *** by SAR,we introduce synthetic aperture ptycho-endoscopy(SAPE)for micro-endoscopic imaging beyond the diffraction *** operates by hand-holding a lensless fiber bundle tip to record coherent diffraction patterns from *** fiber cores at the distal tip modulate the diffracted wavefield within a confined area,emulating the role of the‘airborne antenna’in *** handheld operation introduces positional shifts to the tip,analogous to the aircraft’s *** shifts facilitate the acquisition of a ptychogram and synthesize a large virtual aperture extending beyond the bundle’s physical *** mitigate the influences of hand motion and fiber bending through a low-rank spatiotemporal decomposition of the bundle’s modulation *** tests demonstrate the ability to resolve a 548-nm linewidth on a resolution *** achieved space-bandwidth product is~1.1 million effective pixels,representing a 36-fold increase compared to that of the original fiber ***,SAPE’s refocusing capability enables imaging over an extended depth of field exceeding 2 *** aperture synthesizing process in SAPE surpasses the diffraction limit set by the probe’s maximum collection angle,opening new opportunities for both fiber-based and distal-chip endoscopy in applications such as medical diagnostics and industrial inspection.

关键词： fiber antenna bundle

0.5mm金刚石X射线相位延迟板及偏振度的标定

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光学学报 2002年第6期22卷 713-717页

作者：潘国强 Lonny Berman 中国科学技术大学国家同步辐射实验室合肥230029 National Synchrotron light source Brookhaven National Laboratory

在利用同步辐射光源的偏振特性进行自旋相关X射线散射及吸收谱实验来研究材料的磁学性质时 ,需要应用圆偏振光 ,这就提出了对具有高通量、高偏振度、波长连续可调的圆偏振X射线的需求 ;另一方面标定实验所用X射线的圆偏振度也成为这一... 详细信息

在利用同步辐射光源的偏振特性进行自旋相关X射线散射及吸收谱实验来研究材料的磁学性质时 ,需要应用圆偏振光 ,这就提出了对具有高通量、高偏振度、波长连续可调的圆偏振X射线的需求 ;另一方面标定实验所用X射线的圆偏振度也成为这一研究领域的关键技术。由于X射线多光束衍射强度与σ场和π场的光程差δ相关 ,通过测量圆偏振分析晶体的多光束衍射的强度分布 ,可以获得入射X射线的圆偏振度。实验在美国国家同步辐射光源实验室X2 5光束线实验站进行 ,光子能量为 7.1keV的圆偏振X射线由线偏振X射线经过一厚度为0 .5mm、晶面为 [111]的金刚石晶体产生。通过测量多光束衍射强度 ,确定了斯托克斯参量。

关键词：金刚石标定同步辐射 X射线相位延迟板圆偏振度斯托克斯参量磁学性质