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v.rtical redistribution of drifting benthic inv.rtebrates in the Kedrov.ya Riv.r, Primorsky Region of Russia

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Open Journal of Ecology 2014年第2期4卷 53-59页

作者： maxim v. Astakhov.v.ctor v. Bogatov Institute of Biology and Soil Sciences Russian Academy of Sciences Vladivostok Russia

The v.rtical distribution of morphologically different drifting inv.rtebrates (mayfly and dipteran larv.e) in a small salmon riv.r was studied. Drifting inv.rtebrates were caught with the Astakhov.s sampler equipped with three driftnets placed one abov. another. The av.rage annual drift rate in different lev.ls of a water column was practically the same, while the drift density decreased from the bottom to the surface. Ov.r the course of 24 hours, the drifting organisms did not show clear preference for a particular water layer. Inv.rtebrates were constantly redistributed between the upper and lower lev.ls at approximately 30 - 90 min interv.ls. This redistribution appears to be linked to the fact that inv.rtebrates of the same taxa, which entered into water column from different bottom sites become activ. at different times.

关键词： Sampling Benthos Stream Drift v.rtical Distribution

Ensemble learning-iterativ. training machine learning for uncertainty quantification and automated experiment in atom-resolv.d microscopy

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npj Computational Materials 2021年第1期7卷 909-916页

作者： Ayana Ghosh Bobby G.Sumpter Ondrej Dyck Sergei v.Kalinin maxim Ziatdinov Center for Nanophase Materials Sciences Oak Ridge National LaboratoryOak RidgeTNUSA Computational Sciences and Engineering Div.sion Oak Ridge National LaboratoryOak RidgeTNUSA

Deep learning has emerged as a technique of choice for rapid feature extraction across imaging disciplines,allowing rapid conv.rsion of the data streams to spatial or spatiotemporal arrays of features of ***,applications of deep learning in experimental domains are often limited by the out-of-distribution drift between the experiments,where the network trained for one set of imaging conditions becomes sub-optimal for different *** limitation is particularly stringent in the quest to hav. an automated experiment setting,where retraining or transfer learning becomes impractical due to the need for human interv.ntion and associated *** we explore the reproducibility of deep learning for feature extraction in atom-resolv.d electron microscopy and introduce workflows based on ensemble learning and iterativ. training to greatly improv. feature *** approach allows incorporating uncertainty quantification into the deep learning analysis and also enables rapid automated experimental workflows where retraining of the network to compensate for out-of-distribution drift due to subtle change in imaging conditions is substituted for human operator or programmatic selection of networks from the *** methodology can be further applied to machine learning workflows in other imaging areas including optical and chemical imaging.

关键词： learning experiment enable

Gaussian process analysis of electron energy loss spectroscopy data:multiv.riate reconstruction and kernel control

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npj Computational Materials 2021年第1期7卷 1395-1404页

作者： Sergei v.Kalinin Andrew R.Lupini Rama K.v.sudev.n maxim Ziatdinov Center for Nanophase Materials Sciences Oak Ridge National LaboratoryOak RidgeTNUSA

Adv.nces in hyperspectral imaging including electron energy loss spectroscopy bring forth the challenges of exploratory and physics-based analysis of multidimensional data *** multiv.riate linear unmixing methods generally explore similarities in the energy dimension,but ignore correlations in the spatial *** the same time,Gaussian process(GP)explicitly incorporate spatial correlations in the form of kernel functions but is computationally ***,we implement a GP method operating on the full spatial domain and reduced representations in the energy *** this multiv.riate GP,the information between the components is shared v.a a common spatial kernel structure,while allowing for v.riability in the relativ. noise magnitude or image *** explore the role of kernel constraints on the quality of the reconstruction,and suggest an approach for estimating them from the experimental *** further show that spatial information contained in higher-order components can be reconstructed and spatially localized.

关键词： domain kernel multiv.riate

Bridging microscopy with molecular dynamics and quantum simulations: an atomAI based pipeline

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npj Computational Materials 2022年第1期8卷 705-715页

作者： Ayana Ghosh maxim Ziatdinov.Ondrej Dyck Bobby G.Sumpter Sergei v.Kalinin Center for Nanophase Materials Sciences Oak Ridge National LaboratoryOak RidgeTN37831USA Computational Sciences and Engineering Div.sion Oak Ridge National LaboratoryOak RidgeTN37831USA

Recent adv.nces in (scanning) transmission electron microscopy hav. enabled a routine generation of large v.lumes of high-v.racity structural data on 2D and 3D materials,naturally offering the challenge of using these as starting inputs for atomistic *** this fashion,the theory will address experimentally emerging structures,as opposed to the full range of theoretically possible atomic ***,this challenge is highly nontriv.al due to the extreme disparity between intrinsic timescales accessible to modern simulations and microscopy,as well as latencies of microscopy and simulations per *** this issue requires as a first step bridging the instrumental data flow and physics-based simulation env.ronment,to enable the selection of regions of interest and exploring them using physical *** we report the dev.lopment of the machine learning workflow that directly bridges the instrument data stream into Python-based molecular dynamics and density functional theory env.ronments using pre-trained neural networks to conv.rt imaging data to physical *** pathways to ensure structural stability and compensate for the observ.tional biases univ.rsally present in the data are identified in the *** approach is used for a graphene system to reconstruct optimized geometry and simulate temperature-dependent dynamics including adsorption of Cr as an ad-atom and graphene healing ***,it is univ.rsal and can be used for other material systems.

关键词： dynamics bridges offering

Anomalous Laterally Stressed Kinetically Trapped DNA Surface Conformations

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Nano-Micro Letters 2021年第8期13卷 263-280页

作者： v.lery v.Prokhorov.Nikolay A.Barinov.Kirill A.Prusakov.Ev.eniy v.Dubrov.n maxim D.Frank-Kamenetskii Dmitry v.Klinov Federal Research and Clinical Center of Physical-Chemical Medicine Malaya Pirogovskaya1aMoscow 119435Russian Federation A.N.Frumkin Institute of Physical Chemistry and Electrochemistry RASLeninsky prospect Moscow 199071 Russian Federation 3 Moscow Institute of Physics and TechnologyInstitutskiy per.9Dolgoprudny141700 MoscowRussian Federation Lomonosov.Moscow State Univ.rsity Leninskie gory1-2Moscow 119991Russian Federation Department of Biomedical Engineering Boston University44 Cummington MallBoston MA02215USA

Up to now,the DNA molecule adsorbed on a surface was believ.d to always preserv. its nativ. *** belief implies a negligible contribution of lateral surface forces during and after DNA adsorption although their impact has nev.r been ***-resolution atomic force microscopy was used to observ. that stiff DNA molecules kinetically trapped on monomolecular films comprising one-dimensional periodically charged lamellar templates as a single layer or as a sublayer are ov.rsaturated by sharp discontinuous kinks and can also be locally melted and *** argue that kink/anti-kink pairs are induced by an ov.rcritical lateral bending stress(>30 pNnm)inev.table for the highly anisotropic 1D-1D electrostatic interaction of DNA and underlying rows of positiv. surface *** addition,the unexpected kink-inducing mechanical instability in the shape of the template-directed DNA confined between the positiv.ly charged lamellar sides is observ.d indicating the strong impact of *** prev.ously reported anomalously low v.lues of the persistence length of the surface-adsorbed DNA are explained by the impact of the surface-induced low-scale *** sites of the local melting and supercoiling are conv.ncingly introduced as other lateral stress-induced structural DNA anomalies by establishing a link with DNA high-force *** results open up the study in the completely unexplored area of the principally anomalous kinetically trapped DNA surface conformations in which the DNA local mechanical response to the surface-induced spatially modulated lateral electrostatic stress is essentially *** underlying rich and complex in-plane nonlinear physics acts at the nanoscale beyond the scope of applicability of the worm-like chain approximation.

关键词： DNA surface conformations Kinetic trapping Lateral stress Periodically charged surface DNA kinks

Transv.rse magnetoresistance peculiarities of thermoelectric Lu-doped Bi_2Te_3 compound due to strong electrical disorder

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Journal of Rare Earths 2019年第3期37卷 292-298页

作者： Oleg Iv.nov.maxim Yaprintsev.Elena Danshina Belgorod State Univ.rsity Belgorod State Technological Univ.rsity named after v.G.Shukhov

The n-type thermoelectric Bi_(1.9)Lu_(0.1)Te_3 was prepared by microwav.-solv.thermal method and spark plasma sintering. The magnetic field and temperature dependences of transv.rse magneto resistance measured within temperature 2-200 K interv.l allow finding the peculiarities characteristic for strongly disordered and inhomogeneous semiconductors. The first peculiarity is due to appearance of linear-inmagnetic field contribution to the total magneto resistance reflected in a crossov.r from quadratic magnetoresistance at low magnetic fields to linear magneto resistance at high magnetic fields. The linear magnetoresistance can result from the Hall resistance picked up from macroscopically distorted current paths due to local v.riations in stoichiometry of the compound studied. The second peculiarity is that both linear magnetoresistance magnitude and crossov.r field are functions of carrier mobility which is in agreement with the Parish and Littlewood model dev.loped for disordered and inhomogeneous semiconductors. An increase in the mobility due to a decrease in temperature is accompanied by an increase in the magnetoresistance magnitude and a decrease in the crossov.r field. Finally, the third peculiarity is related to the remarkable dev.ation of the total magnetoresistance measured at v.rious temperatures from the Kohler's rule. Presence of strong inhomogeneity and disorder in the Bi_(1.9)Lu_(0.1)Te_3 structure concluded from the magnetoresistance peculiarities can be responsible for the remarkable reduction in the total thermal conductiv.ty of this compound.

关键词： Bismuth telluride Linear positiv. magnetoresistance Semiconductors Thermoelectric material Carrier mobility Kohler’s rule

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1,2-二甲基咪唑啉的合成及表征

有机化学 2009年第5期29卷 802-805页

作者：徐文清聂万丽 Borzov.maxim v. 马兵锋西北大学化学系西安710069 国立莫斯科大学化学系莫斯科119992

对1,2-二甲基咪唑啉的合成进行了详细研究.以甲胺水溶液和2-溴乙胺氢溴酸盐(1)为原料进行反应,在两种原料物质的量之比为5∶1,缓缓回流12h的条件下,得到N-甲基乙二胺(2),N-甲基乙二胺经过乙酸化得到N-甲基-N,N′-二乙酰基乙二胺(3),然后... 详细信息

对1,2-二甲基咪唑啉的合成进行了详细研究.以甲胺水溶液和2-溴乙胺氢溴酸盐(1)为原料进行反应,在两种原料物质的量之比为5∶1,缓缓回流12h的条件下,得到N-甲基乙二胺(2),N-甲基乙二胺经过乙酸化得到N-甲基-N,N′-二乙酰基乙二胺(3),然后,N-甲基-N,N′-二乙酰基乙二胺和氧化钙在高温下关环得到1,2-二甲基咪唑啉(4).并对所得到的产物1,2-二甲基咪唑啉经元素分析,1HNMR,IR和GC-MS得到了表征.

关键词： N-甲基-N,N′-二乙酰基乙二胺成环反应 1,2-二甲基咪唑啉水解

Adaptiv. data fusion framework for modeling of non-uniform aerodynamic data

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Chinese Journal of Aeronautics 2023年第7期36卷 316-336页

作者： v.nh PHAM maxim TYAN Tuan Anh NGUYEN Chi-Ho LEE L.v.Thang NGUYEN Jae-Woo LEE Department of Aerospace Information Engineering Konkuk UniversitySeoul 05029Republic of Korea Konkuk Aerospace Design-Airworthiness Institute Konkuk UniversitySeoul 05029Republic of Korea

Multi-fidelity Data Fusion(MDF)frameworks hav. emerged as a prominent approach to producing economical but accurate surrogate models for aerodynamic data modeling by integrating data with different fidelity ***,most existing MDF frameworks assume a uniform data structure between sampling data sources;thus,producing an accurate solution at the required lev.l,for cases of non-uniform data structures is *** address this challenge,an Adaptiv. Multi-fidelity Data Fusion(AMDF)framework is proposed to produce a composite surrogate model which can efficiently model multi-fidelity data featuring non-uniform ***,the design space of the input data with non-uniform data structures is decomposed into subdomains containing simplified ***,different MDF frameworks and a rule-based selection process are adopted to construct multiple local models for the subdomain *** the other hand,the Enhanced Local Fidelity Modeling(ELFM)method is proposed to combine the generated local models into a unique and continuous global ***,the resulting model inherits the features of local models and approximates a complete database for the whole design *** v.lidation of the proposed framework is performed to demonstrate its approximation capabilities in(A)four multi-dimensional analytical problems and(B)a practical engineering case study of constructing an F16C fighter aircraft’s aerodynamic *** comparisons of the generated models using the proposed AMDF framework and conv.ntional MDF approaches using a single global modeling algorithm are performed to rev.al the adaptability of the proposed approach for fusing multi-fidelity data featuring non-uniform ***,the results indicated that the proposed framework outperforms the state-of-the-art MDF approach in the cases of non-uniform data.

关键词： Aerodynamic modeling Data fusion Div.rse data structure Multi-fidelity data Multi-fidelity surrogate modeling

Bistable lasing in parity-time symmetric coupled fiber rings

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Photonics Research 2018年第4期6卷 I0018-I0022页

作者： SERGEY v. SMIRNOv.maxim O. MAKARENKO SERGEY v. SUCHKOv.DMITRY CHURKIN ANDREY A. SUKHORUKOv Nov.sibirsk State Univ.rsity 2 Pirogova Street Novosibirsk 630090 Russia Nonlinear Physics Centre Research School of Physics and Engineering Australian National University Canberra ACT 2601 Australia

We propose a parity-time(PT) symmetric fiber laser composed of two coupled ring cav.ties with gains and losses,which operates both in PT-symmetric and symmetry-broken regimes depending on the static phase shifts. We perform analytical and numerical analysis by the transfer matrix method taking into account gain saturation and predict laser bistability in the PT-symmetric regime in contrast to a symmetry-broken single-mode *** the PT-broken regime, the generation power counterintuitiv.ly increases with an increase of the cav.ty losses.

关键词：光纤激光器奇偶时间激光双稳态通讯技术