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Partnership for eXtreme Xtallography (PX^(2))—A state-of-the-art experimental facility for extreme-conditions crystallography: A case study of pressure-induced phase transition in natural ilvaite

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Matter and Radiation at Extremes 2022年第2期7卷 62-71页

作者： Jingui Xu Dongzhou Zhang sergey n.Tkachev Przemyslaw K.Dera School of Ocean and Earth Science and Technology Hawai’i Institute of Geophysics and PlanetologyUniversity of Hawai’i at ManoaHonoluluHawaii 96822USA Center for Advanced Radiation Sources University of ChicagoChicagoIllinois 60437USA

Single-crystal x-ray diffraction(SCXRD)is an important tool to study the crystal structure and phase transitions of crystalline materials at elevated *** Partnership for eXtreme Xtallography(PX^(2))program at the GSECARS 13-BM-C beamline of the Advanced Photon Source aims to provide state-of-the-art experimental capabilities to determine the crystal structures of materials under extreme conditions using ***^(2) provides a focused x-ray beam(12318μm^(2))at a monochromatic energy of 28.6 ***-pressure SCXRD experiments are performed with a six-circle diffractometer and a Pilatus3 photon-counting detector,facilitated by a membrane system for remote pressure control and an online ruby fluorescence system for pressure *** efficient,high-quality crystal structure determination at PX^(2) is exemplified by a study of pressure-induced phase transitions in natural ilvaite[CaFe^(2+)_(2 )Fe^(3+)Si_(2)O_(7)O(OH),P2_(1)/a space group].Two phase transitions are observed at high *** SCXRD data confirm the already-known ilvaite-I(P2_(1)/a)→ilvaite-II(Pnam)transformation at 0.4(1)GPa,and,a further phase transition is found to occur at 22.8(2)GPa where ilvaite-II transforms into ilvaite-III(P2_(1)/a).The crystal structure of the ilvaite-III is solved and refined in the P2_(1)/a space *** addition to the ilvaite-I→ilvaite-II→ilvaite-III phase transitions,two minor structural modifications are observed as discontinuities in the evolution of the FeO6 polyhedral geometries with pressure,which are likely associated with magnetic transitions.

关键词： phase extreme transitions

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Investigation of radio pulsar emission features using power spectra

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Research in Astronomy and Astrophysics 2018年第8期18卷 63-70页

作者： Valery M.Malofeev sergey A.Tyul'bashev En.Lebedev Physical Institute of the Russian Academy of Sciences V.V.Vitkevich Pushchino Radio Astronomy ObservatoryPRAO ASC FIANPushchinoRussia

Since 2013, round-the-clock monitoring of the sky has been carried out simultaneously in 96 beams using a high-sensitivity radio telescope called the Large Phased Array （LPA） at the frequency 110.25 MHz. These observations are made under the program of interplanetary plasma investigation. The same data are used to search for pulsars by means of power spectra. To increase the sensitivity of the pulsar search, 500-600 power spectra corresponding to different days of observations are summed. In the integrated spectra of known pulsars, besides expected improvement in signal-to-noise （S/n） ratio for the frequency harmonics, some features are explored in this paper. We present the 27 strongest pulsars which are in a field with declination 21° - 42°. The observable details in the integrated power spectra are connected with the presence of pulsar periods of the second （P2） and third （P3） class, which have been identified. Empirical relations for calculating these periods are obtained. The value P2 is estimated for 26 pulsars, and for 15 sources it is made for the first time. The value P3 is estimated for 13 pulsars, among them these values are given for five sources for the first time.

关键词： pulsars general - pulsars

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Pulsating magneto-dipole radiation of a quaking neutron star powered by energy of Alfvn seismic vibrations

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Research in Astronomy and Astrophysics 2011年第9期11卷 1085-1092页

作者： sergey Bastrukov Jun-Wei Yu Ren-Xin Xu Irina Molodtsova State Key Laboratory of nuclear Physics and Technology School of Physics Peking University Beijing 100871 China Joint Institute for nuclear Research 141980 Dubna Russia

We compute the characteristic parameters of the magneto-dipole radiation of a neutron star undergoing torsional seismic vibrations under the action of Lorentz restoring force about an axis of a dipolar magnetic field experiencing decay. After a brief outline of the general theoretical background of the model of a vibration-powered neutron star, we present numerical estimates of basic vibration and radiation characteristics, such as frequency, lifetime and luminosity, and investigate their time dependence on magnetic field decay. The presented analysis suggests that a gradual decrease in frequencies of pulsating high-energy emission detected from a handful of currently monitored AXP/SGR-like X-ray sources can be explained as being produced by the vibration-powered magneto-dipole radiation of quaking magnetars.

关键词： neutron stars -- torsion Alfv6n vibrations -- vibration powered radiation -- magnetic field decay -- magnetars

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Modern problems of aircraft aerodynamics

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Advances in Aerodynamics 2019年第1期1卷 145-159页

作者： sergey L.Chernyshev sergey V.Lyapunov Andrey V.Wolkov Department of Aerodynamics Central Aerohydrodynamic Institute named after Prof.N.EZhukovsky(TsAGI)140180Zhukovsky str.1ZhukovskyRussia

The article represents the discussion of several separate directions of investigations,which are performed by TsAGI flight vehicles aerodynamics specialists at the *** are some major trends of classical layout of route aircraft and also peculiarities of some prospective flight *** there are some hypersonic vehicles aerodynamics questions examined along with problems of creation of civil supersonic transport *** is a description given for well-known and some newer methods of flow control for drag reduction.

关键词： Aircraft aerodynamics Hypersonic vehicles aerodynamics Civil supersonic transport aircraft Sonic boom

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Formation of Extended Covalently Bonded ni Porphyrin networks on the Au（lll） Surface

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nano Research 2011年第4期4卷 376-384页

作者： sergey A. Krasnikov Catherine M. Doyle natalia n. Sergeeva Alexei B. Preobrajenski nikolay A.Vinogradov Yulia n. Sergeeva Alexei A. Zakharov Mathias O. Senge Attilio A. Cafolla School of Physical Sciences Dublin City University Glasnevin Dublin 9 Ireland Centre tbr Research on Adaptive nanostructures and nanodevices （CRAnn） School of Physics Trinity College Dublin Dublin 2 Ireland SFI Tetrapyrrole Laboratory School of Chemistry Trinity College Dublin Dublin 2 Ireland MAX-Lab Lund University Box 118 22100 Lund Sweden

The growth and ordering of {5,10,15,20-tetrakis（4-bromophenyl）porphyrinato}nickel（II）（niTBrPP） molecules on the Au（111） surface have been investigated using scanning tunnelling microscopy, X-ray absorption, core-level photoemission, and microbeam low-energy electron diffraction. When deposited onto the substrate at room temperature, the niTBrPP forms a well-ordered close-packed molecular layer in which the molecules have a flat orientation with the porphyrin macrocycle plane lying parallel to the substrate. Annealing of the niTBrPP layer on the Au（111） surface at 525 K leads to dissociation of bromine from the porphyrin followed by the formation of covalent bonds between the phenyl substituents of the porphyrin. This results in the formation of continuous covalently bonded porphyrin networks, which are stable up to 800 K and can be recovered after exposure to ambient conditions. By controlling the experimental conditions, a robust, extended porphyrin network can be prepared on the Au（111） surface that has many potential applications such as protective coatings, in sensing or as a host structure for molecules and clusters.

关键词： Porphyrins covalently bonded networks scanning tunnelling microscopy X-ray photoemission spectroscopy near-edge X-ray absorption fine structure Au(111)

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Electromagnetic monitoring in the region of seismic activization (on the Gorny Altai (Russia) example)

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Geodesy and Geodynamics 2019年第6期10卷 460-470页

作者： nina n.nevedrova Aidisa M.Sanchaa Alexander E.Shalaginov sergey M.Babushkin Trofimuk Institute of Petroleum Geology and Geophysics of the Siberian Branch of the RAS Novosibirsk630090Russia Seismological Branch of Geophysical Survey of the Russian Academy of Sciences 3 Academician Koptug ave.Novosibirsk630090Russia

Based on the analysis of the field data of nonstationary electromagnetic soundings with different installations,the evolution of the stressed state of the geological massif in the epicentral region of the destructive 2003 M_w7.3 Chuya earthquake is investigated in the *** measurements by these methods were executed in a lot of regular points located at two sites of the western part of the Chuya basin of Gorny Altai(Russian Federation).The field works have been performed for 13 *** developed a measurement technique using data from the three Transient Electromagnetic Method(TEM)method settings for determination of the resistivity anisotropy *** of the field data is carried out based on the inverse problem solution,and further,taking into account the geological structure and seismological data,variations of true electrophysical characteristics of the cross-section(electrical resistivity and resistivity anisotropy coefficient)are *** to the TEM data acquired in the 1980 s,the geoelectric parameters of rocks in the period of low seismic activity were *** of the results of quantitative interpretation of the modern measurements(2004-2016)with those taken before the Chuya event allows tracing a change in the geoelectric parameters of the cross-section in the aftershock period,and on this basis tracking the evolution of the rock massif after the destructive seismic impact.

关键词： Transient electromagnetic Resistivity anisotropy coefficient Time-lapse survey Gorny Altai Chuya basin

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Modified Alumina Cement with High Service Properties

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China's Refractories 2016年第4期25卷 1-5页

作者： sergey M.LOGVInKOV Galinan.SHABAnOVA Alia n.KOROHODSKA Elena V.KHRYSTYCH Kharkov national University of Economic after named of S. Kuznets Kharkov 61166 Ukraine national Technical University “Kharkov Polytechnic Institute” Kharkov 61002 Ukraine national University of Civil Protection of Ukraine Kharkov 61023 Ukraine

This scientific paper gives consideration to the information on the contemporary structure of binary systems and three-component CaO-Al_2O_3-ZrO_2 system required to select rational parameters for the synthesis of cementing *** production process of experimental clinker that has a Ca_7Al_6ZrO_（18） composition has been *** data of X-ray phase analysis and petrographic analysis of the experimental composition of special cement have been given and the reasons for availability of inappropriate phases have been *** processes of hydration hardening of the cement stone have been studied and the data of differential thermal analysis were used for the establishment of the hydration mechanism for basic crystal phases in the cement clinker *** differences in the hydration processes of experimental special cement were analyzed in comparison with known mechanisms.A possibility of the exploitation of special binder in contact with ZrO_2（CaO-stabilized）was tested using the specimens of fine concrete that were subjected to thermal treatment in different *** physical and mechanical properties of specimens and the mineralogical composition of concretes were given based on the data of X-ray analysis and the petrographic *** cement additive was selected and its amount in the concrete composition was defined to slow-down the hardening and the mixture plasticization *** relationships of physical and mechanical characteristics of concrete specimens were defined experimentally as a function of granulometric composition of the filler and thermal treatment *** investigation data of corrosion resistance obtained using the static method were used to find out if experimental concretes can operate in contact with the steel-smelting alkaline slag.

关键词： hydration binder hardening smelting inappropriate Alumina Modified alkaline possibility aggregate

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Strain-induced resonances in the dynamical quadratic magnetoelectric response of multiferroics

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npj Computational Materials 2020年第1期6卷 1156-1161页

作者： S.Omid Sayedaghaee Charles Paillard sergey Prosandeev Bin Xu Laurent Bellaiche Physics Department and Institute for nanoscience and Engineering University of ArkansasFayettevilleArkansas 72701USA Microelectronics-Photonics Program University of ArkansasFayettevilleArkansas 72701USA Laboratoire Structures Propriétés et Modélisation des SolidesCentraleSupélecCNRS UMR 8580UniversitéParis-Saclay91190 Gifsur-YvetteFrance Institute of Physics and Physics Department of Southern Federal University Rostov-na-Donu 344090Russia School of Physical Science and Technology Soochow UniversitySuzhouJiangsu 215006China

For the last few years,the research interest in magnetoelectric(ME)effect,which is the cross-coupling between ferroelectric and magnetic ordering in multiferroic materials,has experienced a significant *** extensive recent studies are not only conducted towards the design of sensors,actuators,transducers,and memory devices by taking advantage of the cross-control of polarization(or magnetization)by magnetic(or electric)fields,but also aim to create a clearer picture in understanding the sources of ME responses and the novel effects associated with *** we derive analytical models allowing to understand the striking and novel dynamics of ME effects in multiferroics and further confirm it with atomistic ***,the role of strain is revealed to lead to the existence of electroacoustic magnons,a new quasiparticle that mixes acoustic and optical phonons with magnons,which results in resonances and thus a dramatic enhancement of magnetoelectric ***,a unique aspect of the dynamical quadratic ME response under a magnetic field with varying frequencies,which is the second harmonic generation(SHG),has not been discussed prior to the present *** SHGs put emphasis on the fact that nonlinearities should be considered while dealing with such systems.

关键词： quadratic dynamical resonance

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Development of a homogenous assay based on fluorescent imprinted nanoparticles for analysis of nitroaromatic compounds

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nano Research 2019年第12期12卷 3044-3050页

作者： Asma Elbelazi Francesco Canfarotta Joanna Czulak Michael J.Whitcombe sergey Piletsky Elena Piletska Chemistry Department University of LeicesterLEI 7RHLeicesterUK Chemistry Department University of TripoliTripoliLibya MIP Diagnostics Ltd. Colworth Science ParkShambrookBedfordMK441LQUK

Herein we describe the development of a homogeneous assay for the detection of 4-nitroaniline(4-nA)and 2,4-dinitroaniline(2,4-dinA).Thisassay relies on fluorescent molecularly imprinted nanoparticles(nano MIPs)which,upon interaction with the target analytes,generate areduction in fluorescence emission intensity(quenching).This is due to a resp on sive fluorescent monomer(n-2-propenyl-(5-dimethylamino)-1-naphthalene sulphonamide)employed in the manufacture of the nanoMIPs which,by virtue of the imprinting process,is capable of selectiveinteraction with the target an alyte,thus giving rise to a quenching *** experiments showed excellent recognition propertiestoward the target *** optimal conditions,the fluorescence intensity of these nano MIPs decreased as the concentration of theimprinted analyte increased from 10 nM to 2.71 pM.A linear relation between the negative logarithm of 4-nA or 2,4-dinA concentrations and the fluorescence intensity for both nanosystems was found(R^2=0.991 and R^2=0.9895),with excellent sensitivity(limit of detection(LOD)=7 and 6 nM,respectively).Furthermore,both nanosystems have been successfully applied for detection of 4-nA or 2,4-dinA in tap water,withrecoveries between 90%to 100.6%and 92%to 100.3%,*** to the versatility of the imprinting process,this nanosystemholds the potential for further development of several optical sensors for many other compounds.

关键词： molecularly imprinted polymers quenching homogeneous assay nitroaromatic compounds

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Prediction of Melting Paths of Wollastonite-Containing Compositions

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China's Refractories 2020年第3期29卷 13-18页

作者： sergey M.LOGVInKOV Ihor A.OSTAPEnKO Oksana n.BORISEnKO Olga B.SKORODUMOVA Andriy A.IVASHURA Kharkiv national University of Economics named after Semen Kuznets PSC “Druzhkovka Refractory Plant” national University of Civil Defence of Ukraine

The article analyzed the main groups of thermal insulation(TIM) and slag-forming(SFM) mixtures produced by leading foreign companies: acidic ones based on the SiO2-Al2O3system, basic ones based on the Ca O-Mg O-Al2O3system and medium basic ones based on the Ca O(Mg O) system-Al2O3-SiO2. It is shown that achieving the necessary properties of the SFM and TIM requires strict observance of the mass content of the components of mixtures produced on the basis of synthetic materials in granular form with a given dispersion. Compliance with a given composition and dispersion is associated with the need to provide a given melting temperature(for intermediate ladles 1 250-1 450 °C, for molds 950-1 150 °C), neutrality to the cast metal, protection of the melt from secondary oxidation, minimization of heat loss from the melt mirror, absorption of non-metallic inclusions of various natures(Al2O3, Ca O, SiO2, TiO2, less often Mg O-containing) and sizes; as well as a number of specific requirements: compatibility with the working layer of the lining of the bucket, maintaining the work of the stoppers, minimizing harmful gaseous emissions, etc. It is known that Al2O3, TixOy, and Ca O refractory inclusions in steel cause the majority of defects on the surface of a cold-rolled sheet, therefore, the aim of the work was to analyze the physicochemical regularities and melting paths of the wollastonite-containing compositions during the assimilation of nonmetallic inclusions by them. To analyze the melting paths of the wollastonite-containing compositions in the Ca O-Al2O3-SiO2system, a diagram of the primary crystallization field of anorthite and the adjacent boundary curves is shown, indicating the directions of temperature drop and designating invariant points. The presented scheme adequately reflects the topological regularities of the state diagram of the Ca O-Al2O3-SiO2system. To analyze the melting paths of the wollastonitecontaining SFM compositions during the assimilation of Ti

关键词： Heat-insulating mixtures Slag-forming mixtures Solid-phase interaction Wollastonite-containing compositions

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