Effect of Organic–Cation Exchange Reaction of Perovskites in Water: H-Bond Assisted Self-Assembly, Black Phase Stabilization, and Single-Particle Imaging

2019 ◽  
Vol 2 (6) ◽  
pp. 4496-4503 ◽  
Author(s):  
Atanu Jana ◽  
Kwang S. Kim
Keyword(s):  
Cation Exchange ◽  
Exchange Reaction ◽  
Single Particle ◽  
Self Assembly ◽  
Organic Cation ◽  
Phase Stabilization ◽  
Cation Exchange Reaction ◽  
Particle Imaging ◽  
Single Particle Imaging

scholarly journals Ethylammonium Lead Iodide Formation in MAPbI3 Precursor Solutions by DMF Decomposition and Organic Cation Exchange Reaction

Crystals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 162
Author(s):  
Ryan Taoran Wang ◽  
Elton Enchong Liu ◽  
Alex Fan Xu ◽  
Lory Wenjuan Yang ◽  
Jason Yuanzhe Chen ◽  
...  
Keyword(s):  
Cation Exchange ◽  
Exchange Reaction ◽  
Organic Cation ◽  
Annealing Process ◽  
Diffraction Measurement ◽  
X Ray Diffraction ◽  
Lead Iodide ◽  
X Ray ◽  
Cation Exchange Reaction

Extra peaks have constantly been observed in the X-ray diffraction measurement for the CH3NH3PbI3 film. Such mysteries have now been uncovered in this paper, in which powder X-ray diffraction, in situ X-ray diffraction, and scanning electron microscopy measurements were conducted, and these peaks were attributed to the ethylammonium lead iodide (CH3CH2NH3PbI3/EAPbI3). It was found that the formation of EAPbI3 was triggered by the breakdown of N, N-dimethylformamide (DMF), which was adopted as the solvent in the preparation of the precursor solutions. EAPbI3 was generated by the organic cation exchange reaction in the subsequent annealing process. A simple solution for this problem is proposed in this paper as well, which would hopefully help the community to eradicate this impurity.

A balanced cation exchange reaction toward highly uniform and pure phase FA1−xMAxPbI3 perovskite films

2016 ◽  
Vol 4 (37) ◽  
pp. 14437-14443 ◽  
Author(s):  
Fuxiang Ji ◽  
Li Wang ◽  
Shuping Pang ◽  
Peng Gao ◽  
Hongxia Xu ◽  
...  
Keyword(s):  
Cation Exchange ◽  
Exchange Reaction ◽  
Organic Cation ◽  
Cation Exchange Reaction ◽  
Pure Phase ◽  
Highly Uniform

The organic cation exchange temperature was optimized toward the formation of highly uniform FA based perovskite films.

scholarly journals An encryption–decryption framework to validating single-particle imaging

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhou Shen ◽  
Colin Zhi Wei Teo ◽  
Kartik Ayyer ◽  
N. Duane Loh
Keyword(s):  
Conceptual Framework ◽  
Single Particle ◽  
Latent Variables ◽  
Ground Truth ◽  
Resolving Power ◽  
Validation Measure ◽  
Encryption Decryption ◽  
Diffraction Patterns ◽  
Particle Imaging ◽  
Single Particle Imaging

AbstractWe propose an encryption–decryption framework for validating diffraction intensity volumes reconstructed using single-particle imaging (SPI) with X-ray free-electron lasers (XFELs) when the ground truth volume is absent. This conceptual framework exploits each reconstructed volumes’ ability to decipher latent variables (e.g. orientations) of unseen sentinel diffraction patterns. Using this framework, we quantify novel measures of orientation disconcurrence, inconsistency, and disagreement between the decryptions by two independently reconstructed volumes. We also study how these measures can be used to define data sufficiency and its relation to spatial resolution, and the practical consequences of focusing XFEL pulses to smaller foci. This conceptual framework overcomes critical ambiguities in using Fourier Shell Correlation (FSC) as a validation measure for SPI. Finally, we show how this encryption-decryption framework naturally leads to an information-theoretic reformulation of the resolving power of XFEL-SPI, which we hope will lead to principled frameworks for experiment and instrument design.

scholarly journals Comparison of EMC and CM methods for orienting diffraction images in single-particle imaging experiments

IUCrJ ◽  
2021 ◽  
Vol 8 (6) ◽  
Author(s):  
Miklós Tegze ◽  
Gábor Bortel
Keyword(s):  
Intensity Distribution ◽  
Single Particle ◽  
Free Electron ◽  
Free Electron Laser ◽  
Biological Molecules ◽  
Crucial Step ◽  
X Ray ◽  
Diffraction Patterns ◽  
Particle Imaging ◽  
Single Particle Imaging

In single-particle imaging (SPI) experiments, diffraction patterns of identical particles are recorded. The particles are injected into the X-ray free-electron laser (XFEL) beam in random orientations. The crucial step of the data processing of SPI is finding the orientations of the recorded diffraction patterns in reciprocal space and reconstructing the 3D intensity distribution. Here, two orientation methods are compared: the expansion maximization compression (EMC) algorithm and the correlation maximization (CM) algorithm. To investigate the efficiency, reliability and accuracy of the methods at various XFEL pulse fluences, simulated diffraction patterns of biological molecules are used.

scholarly journals Virus detection and identification in minutes using single-particle imaging and deep learning

2020 ◽  
Author(s):  
Nicolas Shiaelis ◽  
Alexander Tometzki ◽  
Leon Peto ◽  
Andrew McMahon ◽  
Christof Hepp ◽  
...  
Keyword(s):  
Neural Network ◽  
Deep Learning ◽  
Single Particle ◽  
Virus Detection ◽  
Diagnostic Methods ◽  
Clinical Samples ◽  
Promising Alternative ◽  
Detection And Identification ◽  
Particle Imaging ◽  
Single Particle Imaging

AbstractThe increasing frequency and magnitude of viral outbreaks in recent decades, epitomized by the current COVID-19 pandemic, has resulted in an urgent need for rapid and sensitive viral diagnostic methods. Here, we present a methodology for virus detection and identification that uses a convolutional neural network to distinguish between microscopy images of single intact particles of different viruses. Our assay achieves labeling, imaging and virus identification in less than five minutes and does not require any lysis, purification or amplification steps. The trained neural network was able to differentiate SARS-CoV-2 from negative clinical samples, as well as from other common respiratory pathogens such as influenza and seasonal human coronaviruses, with high accuracy. Single-particle imaging combined with deep learning offers a promising alternative to traditional viral diagnostic methods, and has the potential for significant impact.

NIR Enhancement of β-NaGdF4∶Yb3+,Tm3+ Nanocrystals via Cation Exchange Reaction

2017 ◽  
Vol 38 (10) ◽  
pp. 1267-1272
Author(s):  
贾明理 JIA Ming-li ◽  
张家骅 ZHANG Jia-hua
Keyword(s):  
Cation Exchange ◽  
Exchange Reaction ◽  
Cation Exchange Reaction
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