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spectra properties of Yb^(3+),Er^(3+):Sc_2SiO_5 crystal

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Chinese Physics B 2019年第3期28卷 362-365页

作者： Yanyan Xue Lihe Zheng Dapeng Jiang Qinglin Sai Liangbi Su Jun Xu School of Physics Science and Engineering Institute for Advanced StudyTongji University Shanghai Institute of Ceramics Chinese Academy of Sciences Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences Shanghai Engineering Research Center for Sapphire Crystals

The influence of Er3+ ions on the spectra of Yb^(3+),Er^(3+): Sc_2 SiO_5(SSO) single crystal, which was obtained by Czochralski(Cz) method, is discussed. The absorption coefficient at 980 nm was 13.36 cm^(-1) with a peak absorption cross-section of 1.46 × 10^(-20) cm2. The emission cross-sections at 1034 nm and 1062 nm were 5.5 × 10^(-21) cm^2 and4.9 × 10^(-21) cm^2, respectively. The fluorescence lifetime was estimated as 1.24 ms at 1061 nm. The mechanical properties of SSO single crystal were also presented.

关键词： Yb3+ Er3+: Sc2SiO5 spectra properties mechanical properties

spectra Statistics for the Odd-Odd Nucleus ^(86)Nb

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Chinese Physics Letters 2001年第10期18卷 1327-1330页

作者： ZHENG Ren-Rong ZHU Shun-Quan CHENG Nan-Pu Department of Physics Shanghai Normal UniversityShanghai 200234 Department of Physics:Southwest Normal University Chongqing 400715

The energy levels of the odd-odd nucleus ^(86)Nb at low spins are calculated by using quasi-particles plus a rotor model. The distribution of the nearest-neighbour spacing and the spectral rigidity are studied. We find that the chaotic degree of the energy spectra increases with the increasing spin and reaches a maximum at I = 10;then it decreases gradually for spins above I = 10. The recoil term in the model Haniltonian makes the energy spectra slightly regular. The Coriolis force, however, makes the spectra chaotic and plays a major role in the spectral statistics of the odd-odd nucleus ^(86)Nb.

关键词： chaotic spectra rigidity

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

spectra of Free Diquark in the Bethe-Salpeter Approach

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Communications in Theoretical Physics 2006年第6X期46卷 1031-1039页

作者： YU Yan-Ming KE Hong-Wei DING Yi-Bing GUO Xin-Heng JIN Hong-Ying LI Xue-Qian SHEN Peng- Nian WANG Guo-Li Department of Physics Nankai University Tianjin 300071 China Department of Physics Graduate School of the Chinese Academy of Sciences Beijing 100049 China Institute of Low-Energy Nuclear Physics Beijing Normal University Beijing 100875 China Institute of Modern Physics Zhejiang University Hangzhou 310027 China Institute of High Energy Physics the Chinese Academy of Sciences P.O. Box 918-4 Beijing 100049 China Department of Physics Harbin Institute of Technology Harbin 150001 China

In this work, we employ the Bethe-Salpeter （B-S） equation to investigate the spectra of free diquarks and their B-S wave functions. We find that the B-S approach can be consistently applied to study the diqaurks with two heavy quarks or one heavy and one light quarks, but for two light-quark systems, the results are not reliable. There are a few free parameters in the whole scenario which can only be fixed phenomenologically. Thus, to determine them, one has to study baryons which are composed of quarks and diquarks.

关键词： Bethe-Salpeter equation diquark spectra

spectra and electromagnetic transitions of ^(72-84)Kr in the interacting boson model-1

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Chinese Physics C 2016年第7期40卷 68-72页

作者：白洪波李晓伟吕立君董鸿飞王印张进富 College of Physics and Electronic Information Engineering Chifeng University Chifeng 024001 China

Within the framework of the interacting boson model- 1, the energy levels and electromagnetic transitions in 72-84Kr isotopes are calculated. The structures of the eigenstate and Hamiltonian matrix for some low-lying states are also calculated. The calculated results are compared with available experimental data, and the results are generally in good agreement. The present study shows that the 72,74,76,80,82,84Kr isotopes are in the transition from U（5）→ SU（3）, and 7SKr is in the transition from U（5）→ O（6）.

关键词： even-even Kr nuclei spectra electromagnetic transition the interacting boson model-1

Understanding X-ray absorption spectra by means of descriptors and machine learning algorithms

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npj Computational Materials 2021年第1期7卷 1877-1889页

作者： A.A.Guda S.A.Guda A.Martini A.N.Kravtsova A.Algasov A.Bugaev S.P.Kubrin L.V.Guda P.Šot J.A.van Bokhoven C.Copéret A.V.Soldatov The Smart Materials Research Institute Southern Federal University344090 Sladkova 178/24Rostov-on-DonRussia Institute of mathematics mechanics and computer scienceSouthern Federal University344090 Milchakova 8aRostov-on-DonRussia Department of Chemistry INSTM Reference Center and NIS and CrisDi Interdepartmental CentersUniversity of TorinoVia P.Giuria 7I-10125 TorinoItaly Research Institute of Physics Southern Federal University194Stachki Ave.Rostov-on-Don 344090Russia Department of Chemistry and Applied Biosciences ETH ZurichVladimir-Prelog-Weg 1-58093 ZurichSwitzerland Paul Scherrer Institut Villigen 5232Switzerland

X-ray absorption near-edge structure(XANES)spectra are the fingerprint of the local atomic and electronic structures around the absorbing ***,the quantitative analysis of these spectra is not *** with the most recent advances in this area,for a given spectrum,it is not clear a priori which structural parameters can be refined and how uncertainties should be ***,we present an alternative concept for the analysis of XANES spectra,which is based on machine learning algorithms and establishes the relationship between intuitive descriptors of spectra,such as edge position,intensities,positions,and curvatures of minima and maxima on the one hand,and those related to the local atomic and electronic structure which are the coordination numbers,bond distances and angles and oxidation state on the other *** approach overcoms the problem of the systematic difference between theoretical and experimental ***,the numerical relations can be expressed in analytical formulas providing a simple and fast tool to extract structural parameters based on the spectral *** methodology was successfully applied to experimental data for the multicomponent Fe:SiO_(2)system and reference iron compounds,demonstrating the high prediction quality for both the theoretical validation sets and experimental data.

关键词： spectra spectra absorption

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 *** 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

Site dependent and spatially varying response spectra

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Earthquake Engineering and Engineering Vibration 2019年第3期18卷 497-509页

作者： Hakima Djilali Berkane Zamila Harichane Erkan Celebi Sidi Mohammed Elachachi Geomaterials Laboratory Hassiba Benbouali University of Chlef Chlef 02180 Algeria Department of Civil Engineering Sakarya University Adapazari Turkey University of Bordeaux I2M GCE Department France

The goal of this study is to provide a stochastic method to investigate the eff ects of the randomness of soil properties due to their natural spatial variability on the response spectra spatial variation at sites with varying conditions. For this purpose, Monte Carlo Simulations are used to include the variability of both incident ground motion and soil parameters in the response spectra by mean of an appropriate coherency loss function and a site-dependent transfer function, respectively. The approach is built on the assumption of vertical propagation of SH type waves in soil strata with uncertain parameters. The response spectra are obtained by numerical integration of the governing equation of a single-degree-of-freedom (SDOF) system under non-stationary site-dependent and spatially varying ground motion accelerations simulated with non-uniform spectral densities and coherency loss functions. Numerical examples showed that randomness of soil properties signifi cantly aff ects the amplitudes of the response spectra, indicating that as the heterogeneity induced by the randomness of the parameters of the medium increases, the spectral ordinates attenuate.

关键词： response spectra randomness spectral density Monte Carlo

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 ***,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 *** is the first observation of the resolved hyperfine structure and anticrossing hyperfine levels in the luminescence spectra of a *** narrowest spectral linewidth is only 0.0022 *** 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 *** small random lattice strains characterizing the quality of a crystal can be detected using anticrossing points.

关键词： spectra luminescence hyperfine