scholarly journals AutoDetect-mNP: An Unsupervised Machine Learning Algorithm for Automated Analysis of Transmission Electron Microscope Images of Metal Nanoparticles

2020 ◽  
Author(s):  
Xingzhi Wang ◽  
Jie Li ◽  
Hyun Dong Ha ◽  
Jakob Dahl ◽  
Teresa Head-Gordon ◽  
...  
Keyword(s):  
High Throughput ◽  
Learning Algorithm ◽  
Automated Analysis ◽  
Metal Nanoparticle ◽  
Time Resolved ◽  
Information Richness ◽  
Transmission Electron ◽  
Different Shapes

The synthesis quality of artificial inorganic nanocrystals is most often assessed by transmission electron microscopy (TEM) for which new high-throughput advances have dramatically increased both the quantity and information richness of metal nanoparticle (mNP) characterization. Existing automated data analysis algorithms of TEM mNP images generally adopt a supervised approach, requiring a significant effort in human preparation of labelled data that reduces objectivity, efficiency, and generalizability. We have developed an unsupervised algorithm AutoDetect-mNP for automated analysis of TEM images that objectively extracts morphological information of convex mNPs from TEM images based on their shape attributes, requiring little to no human input in the process. The performance of AutoDetect-mNP is tested on two datasets of bright field TEM images of Au nanoparticles with different shapes, demonstrating that the algorithm is quantitatively reliable, and can thus serve as a generalizable measure of the morphology distributions of any mNP synthesis. The AutoDetect-mNP algorithm will aid in future developments of high-throughput characterization of newly synthesized mNPs, and the future advent of time-resolved TEM studies that can investigate reaction mechanisms of mNP synthesis and reactivity.

scholarly journals AutoDetect-mNP: An Unsupervised Machine Learning Algorithm for Automated Analysis of Transmission Electron Microscope Images of Metal Nanoparticles

2020 ◽  
Author(s):  
Xingzhi Wang ◽  
Jie Li ◽  
Hyun Dong Ha ◽  
Jakob Dahl ◽  
Teresa Head-Gordon ◽  
...  
Keyword(s):  
High Throughput ◽  
Learning Algorithm ◽  
Automated Analysis ◽  
Metal Nanoparticle ◽  
Time Resolved ◽  
Information Richness ◽  
Transmission Electron ◽  
Different Shapes

The synthesis quality of artificial inorganic nanocrystals is most often assessed by transmission electron microscopy (TEM) for which new high-throughput advances have dramatically increased both the quantity and information richness of metal nanoparticle (mNP) characterization. Existing automated data analysis algorithms of TEM mNP images generally adopt a supervised approach, requiring a significant effort in human preparation of labelled data that reduces objectivity, efficiency, and generalizability. We have developed an unsupervised algorithm AutoDetect-mNP for automated analysis of TEM images that objectively extracts morphological information of convex mNPs from TEM images based on their shape attributes, requiring little to no human input in the process. The performance of AutoDetect-mNP is tested on two datasets of bright field TEM images of Au nanoparticles with different shapes, demonstrating that the algorithm is quantitatively reliable, and can thus serve as a generalizable measure of the morphology distributions of any mNP synthesis. The AutoDetect-mNP algorithm will aid in future developments of high-throughput characterization of newly synthesized mNPs, and the future advent of time-resolved TEM studies that can investigate reaction mechanisms of mNP synthesis and reactivity.

scholarly journals AutoDetect-mNP: An Unsupervised Machine Learning Algorithm for Automated Analysis of Transmission Electron Microscope Images of Metal Nanoparticles

2021 ◽  
Author(s):  
Xingzhi Wang ◽  
Jie Li ◽  
Hyun Dong Ha ◽  
Jakob Dahl ◽  
Justin C. Ondry ◽  
...  
Keyword(s):  
High Throughput ◽  
Learning Algorithm ◽  
Automated Analysis ◽  
Metal Nanoparticle ◽  
Time Resolved ◽  
Information Richness ◽  
Transmission Electron ◽  
Different Shapes

The synthesis quality of artificial inorganic nanocrystals is most often assessed by transmission electron microscopy (TEM) for which new high-throughput advances have dramatically increased both the quantity and information richness of metal nanoparticle (mNP) characterization. Existing automated data analysis algorithms of TEM mNP images generally adopt a supervised approach, requiring a significant effort in human preparation of labelled data that reduces objectivity, efficiency, and generalizability. We have developed an unsupervised algorithm AutoDetect-mNP for automated analysis of TEM images that objectively extracts morphological information of convex mNPs from TEM images based on their shape attributes, requiring little to no human input in the process. The performance of AutoDetect-mNP is tested on two datasets of bright field TEM images of Au nanoparticles with different shapes, demonstrating that the algorithm is quantitatively reliable, and can thus serve as a generalizable measure of the morphology distributions of any mNP synthesis. The AutoDetect-mNP algorithm will aid in future developments of high-throughput characterization of newly synthesized mNPs, and the future advent of time-resolved TEM studies that can investigate reaction mechanisms of mNP synthesis and reactivity.

Characterization of JEOL 3000f TEM Equipped for Electron Holography

2000 ◽  
Vol 6 (S2) ◽  
pp. 228-229
Author(s):  
M. A. Schofield ◽  
Y. Zhu
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Design Of Experiment ◽  
Electron Holography ◽  
Fringe Spacing ◽  
Interference Fringes ◽  
Transmission Electron ◽  
Careful Design

Quantitative off-axis electron holography in a transmission electron microscope (TEM) requires careful design of experiment specific to instrumental characteristics. For example, the spatial resolution desired for a particular holography experiment imposes requirements on the spacing of the interference fringes to be recorded. This fringe spacing depends upon the geometric configuration of the TEM/electron biprism system, which is experimentally fixed, but also upon the voltage applied to the biprism wire of the holography unit, which is experimentally adjustable. Hence, knowledge of the holographic interference fringe spacing as a function of applied voltage to the electron biprism is essential to the design of a specific holography experiment. Furthermore, additional instrumental parameters, such as the coherence and virtual size of the electron source, for example, affect the quality of recorded holograms through their effect on the contrast of the holographic fringes.

scholarly journals Imaging, understanding, and control of nanoscale materials transformations

MRS Bulletin ◽  
2021 ◽  
Author(s):  
Haimei Zheng
Keyword(s):  
Solid Electrolyte Interphase ◽  
Time Resolved ◽  
Nanocrystal Growth ◽  
Transmission Electron ◽  
Lithium Dendrites ◽  
Liquid Cell ◽  
Resolution Imaging ◽  
And Control

AbstractThe development of liquid cells for transmission electron microscopy has enabled breakthroughs in our ability to follow nanoscale structural, morphological, or chemical changes during materials growth and applications. Time-resolved high-resolution imaging and chemical analysis through liquids opened the opportunity to capture nanoscale dynamic processes of materials, including reaction intermediates and the transformation pathways. In this article, a series of work is highlighted with topics ranging from liquid cell developments to in situ studies of nanocrystal growth and transformations, dendrite formation, and suppression of lithium dendrites through in situ characterization of the solid–electrolyte interphase chemistry. The understanding garnered is expected to accelerate the discovery of novel materials for applications in energy storage, catalysis, sensors, and other functional devices.

Growth and Characterization of (012)- and (001)-Oriented Epitaxial Anatase Thin Films

2006 ◽  
Vol 46 ◽  
pp. 146-151
Author(s):  
Andriy Lotnyk ◽  
Stephan Senz ◽  
Dietrich Hesse
Keyword(s):  
Thin Films ◽  
Cross Section ◽  
Single Phase ◽  
Electron Beam Evaporation ◽  
X Ray Diffraction ◽  
Tio2 Thin Films ◽  
X Ray ◽  
Transmission Electron

Single phase TiO2 thin films of anatase structure have been prepared by reactive electron beam evaporation. Epitaxial (012)- and (001)-oriented anatase films were successfully obtained on (110)- and (100)-oriented SrTiO3 substrates, respectively. X-ray diffraction and cross section transmission electron microscopy investigations revealed a good epitaxial quality of the anatase films grown on the SrTiO3 substrates.

scholarly journals Structural Characterization of Al0.37In0.63N/AlN/p-Si (111) Heterojunctions Grown by RF Sputtering for Solar Cell Applications

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2236
Author(s):  
Arántzazu Núñez-Cascajero ◽  
Fernando B. Naranjo ◽  
María de la Mata ◽  
Sergio I. Molina
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Interfacial Layer ◽  
Rf Sputtering ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Aln Buffer

Compact Al0.37In0.63N layers were grown by radiofrequency sputtering on bare and 15 nm-thick AlN-buffered Si (111) substrates. The crystalline quality of the AlInN layers was studied by high-resolution X-ray diffraction measurements and transmission electron microscopy. Both techniques show an improvement of the structural properties when the AlInN layer is grown on a 15 nm-thick AlN buffer. The layer grown on bare silicon exhibits a thin amorphous interfacial layer between the substrate and the AlInN, which is not present in the layer grown on the AlN buffer layer. A reduction of the density of defects is also observed in the layer grown on the AlN buffer.

Characterization of Shell Material on Colloidal CdSe/ZnS Quantum Dots

2004 ◽  
Vol 818 ◽  
Author(s):  
Zhiheng Yu ◽  
Li Guo ◽  
Hui Du ◽  
Todd Krauss ◽  
John Silcox
Keyword(s):  
Quantum Dots ◽  
Surface Passivation ◽  
Core Shell ◽  
Shell Material ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Chemical Distribution ◽  
Electron Energy Loss

AbstractScanning transmission electron microscopy (STEM) coupled with electron energy loss spectroscopy (EELS) was used to determine the distribution of ZnS shell material on colloidal core-shell CdSe/ZnS quantum dots (QDs). A sub-nm electron probe was placed at various locations on core-shell QDs to ascertain the chemical distribution of the shell material. While a definite shell of ZnS was detected surrounding the CdSe core, the integrated EELS signals from positions around the QD suggest the distribution of the shell material may not be uniform. A non-uniform shell implies a reduced quality of the QD surface passivation.

MBE Growth and Optical Characterization of InGaN/AlGaN Multiquantum Wells

1996 ◽  
Vol 449 ◽  
Author(s):  
R. Singh ◽  
W.D. Herzog ◽  
D. Doppalapudi ◽  
M.S. ÜnlÜ ◽  
B.B. Goldberg ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Electron Cyclotron Resonance ◽  
Temperature Cycling ◽  
Cross Sectional ◽  
Luminescence Microscopy ◽  
Mbe Growth ◽  
Transmission Electron ◽  
Ingan Quantum Wells

ABSTRACTWe report the growth of InGaN/AIGaN MQWs on c-plane sapphire by electron cyclotron resonance assisted molecular beam epitaxy (ECR-MBE). Two types of structures were investigated; one employing a GaN and the other a A1GaN barrier layer. The first structure consists of five periods of 80 Å thick In0.09Ga0.91N wells separated by 90 Å thick GaN barriers. The second structure consists of|seven periods of 120 Å thick In0.35Ga0.65N wells and Al0.1Ga0.9N barriers. The substrate temperature was kept constant during the growth of both the wells and the barriers, thus avoiding the need for any temperature cycling during the growth, which may lead to interfacial contamination. The films were characterized by cross sectional transmission electron microscopy (TEM), room temperature photoluminescence (PL) and sub-micron resolution luminescence microscopy. TEM images show sharp and abrupt interfaces, thus confirming the high interfacial quality of the MQW structures. Both structures exhibit strong RT luminescence emission peaking at 387 nm (FWHM = 16nm) for the In0.09Ga0.91N/GaN structure and at 463 nm (FWHM = 28nm) for the In0.35Ga0.65N/A10.1Ga0 9N structure. The high resolution luminescence microscopy studies reveal that the radiative recombination for the InGaN quantum wells is 60–70 times more efficient than for the underlying GaN film.

Microstructural characterization of thick YBa2Cu3O7−δ films on improved rolling-assisted biaxially textured substrates

2003 ◽  
Vol 18 (7) ◽  
pp. 1723-1732 ◽  
Author(s):  
K. J. Leonard ◽  
S. Kang ◽  
A. Goyal ◽  
K. A. Yarborough ◽  
D. M. Kroeger
Keyword(s):  
Seed Layer ◽  
Pulsed Laser ◽  
Microstructural Characterization ◽  
Stabilized Zirconia ◽  
Cross Sectional ◽  
Ybco Films ◽  
Transmission Electron ◽  
Critical Current Density Jc

The microstructural changes associated with the reduced dependence of critical current density (Jc) versus thickness of thick, epitaxial YBa2Cu3O7–δ (YBCO) films on rolling-assisted biaxially textured substrates (RABiTS) were investigated. Pulsed laser deposited YBCO films varying in thickness from 1.0 to 6.4 ?m on RABiTS with an architecture of Ni–3 at.% W/Y2O3/yttrium-stabilized-zirconia/CeO2/YBCO were prepared for cross-sectional transmission electron microscopy studies. Dramatic improvements in physical properties and microstructural quality were observed resulting from the use of Ni–3 at.% W substrates, which provided a sharper texture over earlier Ni substrates, and replacement of CeO2 with Y2O3 as the seed layer within the buffers. The YBCO films showed exceptional orientation up to 6.4 μm thickness, with no misoriented grains or dead layers observed and only limited reaction between the YBCO and CeO2 cap layer. The high quality of the films was also attributed in part to the formation of a tungsten oxide layer forming at the top of the Ni–3% W substrate, limiting the growth of deleterious NiO into the conductor.

scholarly journals A direct high-throughput protein quantification strategy facilitates discovery and characterization of a celastrol-derived BRD4 degrader

2021 ◽  
Author(s):  
Neil Connor Payne ◽  
Semer Maksoud ◽  
Bakhos Tannous ◽  
Ralph Mazitschek
Keyword(s):  
Small Molecule ◽  
High Throughput ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Protein Quantification ◽  
Quinone Methide ◽  
Time Resolved ◽  
Protein Levels ◽  
Pentacyclic Triterpenoid

We describe a generalizable time-resolved Förster resonance energy transfer (TR-FRET)-based platform to profile the cellular action of heterobifunctional degraders (or proteolysis-targeting chimeras; PROTACs), capable of both accurately quantifying protein levels in whole cell lysates in less than 1 h and measuring small-molecule target engagement to endogenous proteins, here specifically for human bromodomain-containing protein 4 (BRD4). The detection mix consists of a single primary antibody targeting the protein of interest, a luminescent donor-labeled anti-species nanobody, and a fluorescent acceptor ligand. Importantly, our strategy can readily be applied to other targets of interest and will greatly facilitate the cell-based profiling of small molecule inhibitors and PROTACs in high-throughput format with unmodified cell lines. We furthermore validate our platform in the characterization of celastrol, a p-quinone methide-containing pentacyclic triterpenoid, as a broad cysteine-targeting E3 ubiquitin ligase warhead for potent and efficient targeted protein degradation

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