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Deep learning for determining pure isotropic proton spectra from solidstate spectra

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Magnetic Resonance Letters 2024年第1期4卷 63-64页

作者： Mengjie Qiu Zhong Chen Yanqin Lin Department of Electronic Science Fujian Provincial Key Laboratory of Plasma and Magnetic ResonanceState Key Laboratory of Physical Chemistry of Solid SurfacesXiamen UniversityXiamen361005China

Recently,an article on ^(1)H solid-state NMR spectra was published,in which the authors proposed a deep learning approach to infer the pure isotropic proton NMR spectra obtained at an infinite magic angle spinning(MAS)rate.This approach even allowed to obtain,by far,the best resolved ^(1)H spectra of molecular solids[1](https://***/10.1002/anie.202216607).Deep learning based artificial intelligence is developing rapidly,and its application is deepening.Currently,there are many applications of deep learning in the field of magnetic resonance,such as the reconstruction of the under-sampled multidimensional spectra[2-4],the deconvolution of two-dimensional NMR spectra[5]and noise suppression and weak peak retrial[6],etc.

关键词： spectra isotropic state

High-precision whispering gallery microsensors with ergodic spectra empowered by machine learning

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Photonics Research 2022年第10期10卷 2343-2348页

作者： BING DUAN HANYING ZOU JIN-HUI CHEN CHUN HUI MA XINGYUN ZHAO XIAOLONG ZHENG CHUAN WANG LIANG LIU DAQUAN YANG State Key Laboratory of Information Photonics and Optical Communications School of Information and Communication EngineeringBeijing University of Posts and TelecommunicationsBeijing 100876China Beijing Key Laboratory of Intelligent Telecommunication Software and Multimedia Beijing University of Posts and TelecommunicationsBeijing 100876China Institute of Electromagnetics and Acoustics and Fujian Provincial Key Laboratory of Electromagnetic Wave Science and Detection Technology Xiamen UniversityXiamen 361005China Shenzhen Research Institute of Xiamen University Shenzhen 518000China School of Artificial Intelligence Beijing Normal UniversityBeijing 100875China

Whispering gallery mode(WGM)microcavities provide increasing opportunities for precision measurement due to their ultrahigh sensitivity,compact size,and fast response.However,the conventional WGM sensors rely on monitoring the changes of a single mode,and the abundant sensing information in WGM transmission spectra has not been fully utilized.Here,empowered by machine learning(ML),we propose and demonstrate an ergodic spectra sensing method in an optofluidic microcavity for high-precision pressure measurement.The developed ML method realizes the analysis of the full features of optical spectra.The prediction accuracy of 99.97%is obtained with the average error as low as 0.32 kPa in the pressure range of 100 kPa via the training and testing stages.We further achieve the real-time readout of arbitrary unknown pressure within the range of measurement,and a prediction accuracy of 99.51%is obtained.Moreover,we demonstrate that the ergodic spectra sensing accuracy is∼11.5%higher than that of simply extracting resonating modes’wavelength.With the high sensitivity and prediction accuracy,this work opens up a new avenue for integrated intelligent optical sensing.

关键词： measurement spectra prediction

Impedance spectra of different capacitor technologies

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Journal of Advanced Dielectrics 2023年第4期13卷 76-87页

作者： Rene Kalbitz W€urth Elektronikei Sos GmbH Headquarters Max-Eyth-Straße 1Waldenburg 74638Germany Product Unit Capacitors&Resistors Competence Center Berlin Volmerstraße 10Berlin 12489Germany

This paper reviews the interpretation of impedance and capacitance spectra for different capacitor technologies and discusses how basic electrical characteristics can be inferred from them.The basis of the interpretation is the equivalent circuit for capacitors.It is demonstrated how the model parameters,such as capacitance and equivalent series resistance,can be extracted from the measured spectra.The aspects of measurement accuracy are exemplarily discussed on the measured spectra.

关键词： Impedance capacitance spectra capacitors equivalent circuit equivalent series resistance measurement accuracy

Observation of the hyperfine structure and anticrossings of hyperfine levels in the luminescence spectra of LiYF4:Ho3+

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Light(Science & Applications) 2022年第9期11卷 2155-2165页

作者： KIRILL N.BOLDYREV BORIS Z.MALKIN MARINA N.POPOVA Institute of Spectroscopy Russian Academy of SciencesTroitskMoscow 108840Russia Kazan Federal University Kazan 420008Russia

Resolved hyperfine structure and narrow inhomogeneously broadened lines in the optical spectra of a rare-earth-doped crystal are favorable for the implementation of various sensors.Here,a well-resolved hyperfine structure in the photoluminescence spectra of LiYF4:Ho single crystals and the anticrossings of hyperfine levels in a magnetic field are demonstrated using a self-made setup based on a Bruker 125HR high-resolution Fourier spectrometer.This is the first observation of the resolved hyperfine structure and anticrossing hyperfine levels in the luminescence spectra of a crystal.The narrowest spectral linewidth is only 0.0022 cm-1.This fact together with a large value of the magnetic g factor of several crystal-field states creates prerequisites for developing magnetic field sensors,which can be in demand in modern quantum information technology devices operating at low temperatures.Very small random lattice strains characterizing the quality of a crystal can be detected using anticrossing points.

关键词： spectra luminescence hyperfine

Tracking the reactivity of ozonation towards effluent organic matters from WWTP using two-dimensional correlation spectra

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Journal of Environmental Sciences 2019年第2期31卷 289-298页

作者： Xin Jin Weijie Zhang Rui Hou Pengkang Jin Jina Song Xiaochang C.Wang School of Environmental and Municipal Engineering Xi'an University of Architecture and Technology

The characteristics of effluent organic matter(EfOM) from a wastewater treatment plant(WWTP) during ozonation were investigated using excitation and emission matrix(EEM)spectra, Fourier transform infrared spectroscopy(FT-IR) and high-performance size exclusion chromatography(HPSEC) at different ozone dosages. The selectivity of ozonation towards different constituents and functional groups was analysed using two-dimensional correlation spectra(2D-COS) probed by FT-IR, synchronous fluorescence spectra and HPSEC.The results indicated that ozonation can destroy aromatic structures of EfOM and change its molecular weight distribution(MWD). According to 2D-COS analysis, microbial humiclike substances were preferentially removed, and then the protein-like fractions. Terrestrial humic-like components exhibited inactivity towards ozonation compared with the above two fractions. Protein-like substances with small molecular weight were preferentially reacted during ozonation based on 2D-COS probed by HPSEC. In addition, the selectivity of ozone towards different functional groups of EfOM exhibited the following sequence:phenolic and alcoholic C\O groups > aromatic structures containing C_C double bonds >aliphatic C\H. X-ray photoelectron spectroscopy(XPS) further elucidated the preferential reaction of aromatic structures in EfOM during ozonation.

关键词： Ozonation Two-dimensional correlation spectra (2D-COS) Effluent organic matter (EfOM) Selectivity

spectra and Upconversion of Neodymium Tungstate Crystals

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Journal of Rare Earths 2001年第4期19卷 246-249页

作者：臧竞存刘燕行方方 Coll. of Mat. Sci. and Eng. Beijing Polytech. Univ. Beijing 100022 China

The neodymium tungstate single crystals Nd-2(WO4)(3) were grown using the Czochralski method. The energy level scheme of Nd3+, was obtained through the spectral measurement. The upconversion luminescence of the crystals at 457 and 657 nm, corresponding to the (D5/2-->I11/2)-D-4-I-4 and (2)G(7/2)-->I-4(9/2) transitions, respectively, excited by 808 nm of a laser diode, was observed at room temperature. The fluorescence intensity and the excitation light power have a linear relationship at 457 nm and a quadratic relationship at 657 nm.

关键词： rare earths Nd-2(WO4)(3) single crystals upconversion spectra

spectra OF COMPOSITION GROUPS ON THE WEIGHTED DIRICHLET SPACE OF THE UPPER HALF-PLANE

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Acta Mathematica Scientia 2020年第6期40卷 1739-1752页

作者： M.O.AGWANG J.O.BONYO Department of Pure and Applied Mathematics Maseno UniversityP.O.BOX 333-40105MasenoKenya

We prove that the group of weighted composition operators induced by continuous automorphism groups of the upper half plane U is strongly continuous on the weighted Dirichlet space of U,Dα(U).Further,we investigate when they are isometries on Dα(U).In each case,we determine the semigroup properties while in the case that the induced composition group is an isometry,we apply similarity theory to determine the spectral properties of the group.

关键词： one-parameter semigroup composition operator semigroups strong continuity infinitesimal generator spectra

Quantum Chemical Vibrational Study, FTIR and FT-Raman spectra of 1,3-Diphenyl Propenone

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光谱学与光谱分析 2019年第12期39卷 3932-3939页

作者： Revathi Haldorai M.Thirumalaikumar S.Sampathkrishnan C.Charanya N.Balamurugan Department of Chemistry Karpagam Academy of Higher EducationEachanariCoimbatore641021Tamil NaduIndia Department of Applied Chemistry Sri Venkateswara College of EngineeringSriperumbudur602105Tamil NaduIndia Department of Applied Physics Sri Venkateswara College of EngineeringSriperumbudur602105Tamil NaduIndia Research Scholar Department of Applied PhysicsSri Venkateshwara College of EngineeringSriperumbudur 602105TamilnaduIndia Department of Physics Dhanalakshmi College of EngineeringTambaramChennaiTamilnaduIndia

The Fourier Transform Infrared(FTIR)and Fourier transform Raman(FT-Raman)spectra of 1,3-Diphenyl Propenone were recorded in the regions 4000~400 and 4000~100 cm^-1,respectively,in the solid phase.Molecular electronic energy,geometrical structure,harmonic vibrational spectra was computed at the DFT/6-31G(d,p)and three parameter hybrid functional Lee-Yang-Parr/6-31G(d,p)levels of theory.The vibrational studies were interpreted in terms of potential energy distribution(PED).The results were compared with experimental values with the help of scaling procedures.Most of the modes have wave numbers in the expected range and are in good agreement with computed values and also the molecular properties of Mulliken population analysis have been calculated.Besides,thermodynamic properties were performed.

关键词： FTIR FT-Raman Vibrational spectra PED

STUDY ON THE NANOSECOND TRANSIENT ABSORPTION spectra OF HYPOCRELLIN A

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Science China Chemistry 1992年第12期35卷 1409-1415页

作者：夏万林张曼华蒋丽金王志军 Institute of Photographic Chemistry Academia Sinica Beijing 100101 PRC

In this paper, the nanosecond transient absorption spectra and the fluorescence spectraof Hypocrellin A(HA) are examined in solvents of varying polarity. There are three absorp-tion bands in dilute HA solutions: Ⅰa, Ⅱa are defined as the triplet-triplet absorption ofHA, the band Ⅲa is supposed to be the absorption of the solvent--sepatated ion pair (SSIP).In more concentrated solutions, only the absorption of SSIP was observed. The effects ofsolvent polarity on transient absorption spectra and fluorescence spectra of HA and the effectof oxygen on the intensities of the fluorescence of HA are discussed. Then a reasonablemechanism for the photolysis of HA is proposed.

关键词： hypoerellin A transient absorption spectra solvent-separated ion pair