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The Radcliffe Wave Parameters from Data on Open Star Clusters

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Research in Astronomy and Astrophysics 2024年第3期24卷 106-109页

作者： v.v.Bobylev A.T.Bajkova Pulkovo Astronomical Observatory St-Petersburg 196140Russia

A spectral analysis of the vertical positions and velocities of 374 open star clusters(OSCs)was carried *** took these OSCs from the Hunt and Reffert catalog;they have an average age of about 10 million years,and are located on the galactic plane XY in a narrow zone inclined by 25°to the galactic axis *** following estimates of the parameters of the Radcliffe wave were obtained:(a)the maximum value in periodic perturbations of vertical coordinates Z_(max)=92±10pc with the wavelength of these perturbations λ_(z)=4.82±0.09 kpc;(b)the maximum value of the velocity of vertical disturbances Wmax=4.36±0.12km s^(-1) with disturbance wavelengthλ_(W)=1.78±0.02 *** that the results of the vertical velocity analysis are first-class in accuracy and completely new.

关键词： (Galaxy) local interstellar matter-Galaxy structure-(Galaxy) solar neighborhood

Photoluminescence,structural and antibacterial properties of co-dopedβ-Ca_(3)(PO_(4))_(2)-type phosphates Ca_(8)CuRE(PO_(4))_(7)(RE=Eu-Er)

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Journal of Rare Earths 2024年第9期42卷 1658-1668,I0002页

作者： Ivan v.Nikiforov Ekaterina v.Iliin Bogdan I.Lazoryak Sergey M.Aksenov Pavel v.Slukin Dina v.Deyneko Department of Chemistry Lomonosov Moscow State University119991MoscowRussia Laboratory of Arctic Mineralogy and Material Sciences Kola Science CentreRussian Academy of Sciences184209ApatityRussia Geological Institute Kola Science CentreRussian Academy of Sciences184209ApatityRussia State Scientific Center of Applied Microbiology and Biotechnology of Rospotrebnadzor 24 Block A142279ObolenskRussia

Novel Ca_(8)CuRE(PO_(4))_(7)where RE^(3+)=Eu^(3+),Tb^(3+),Dy^(3+),Ho^(3+)and Er^(3+)were synthesized by a solid-state method in *** structures of the samples were characterized by powder X-ray diffraction using Rietveld refinement to determine the occupation of crystal *** samples are found to have a centrosymmetric structure with space group R3c,as shown by dielectric *** synthesized Ca_(8)CuRE(PO_(4))_(7)samples have multifunctional *** Cu^(2+)ions provide antibacterial properties,while the rare earth elements ions exhibit luminescence properties,and theβ-Ca_3(PO_(4))_(2)-type host is *** photoluminescence properties of RE^(3+)ions were studied and compared with other simmilar Ca_(8)MRE(PO_(4))_(7)phosphates,where M is a divalent *** photoluminescence intensity quenching in terms of energy transfer from RE^(3+)to Cu^(2+)is *** bioactive properties were studied in relation to antibacterial activity against *** and *** syntesized Ca_(8)CuRE(PO_(4))_(7)samples demonstrate very high and stable inhibition of bacteria *** correlation between crystal structure and properties is *** combining multiple approaches to the directio nal design of such materials,several important properties within a single chemical compound to achieve biovisualization and bioactive properties simultaneously can be combined.

关键词： β-Ca_(3)(PO_(4))_(2) Whitlockite-type structure Bioactive phosphates TCP Photoluminescence Rare earths

Performance Analysis of Thermoacoustic Refrigerator of 10 W Cooling Power Made up of Poly-vinyl-Chloride for Different Parallel Plate Stacks by Using Helium as a Working Fluid

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Journal of Thermal Science 2021年第6期30卷 2037-2055页

作者： N v Shivakumara BHEEMSHA Arya Department of Mechanical Engineering BMS College of EngineeringBengaluru 560019India Department of Mechanical Engineering Government PolytechnicChannasandraBengaluru 560067India

Refrigerants are usually provided in the conventional refrigeration system although the refrigerants produce Chlorofluorocarbons(CFCs)and Hydro-chlorofluorocarbons(HCFCs),which are hazardous to the ***,these disadvantages can be overcome by using air or inert gas in the thermoacoustic refrigeration *** the present experimental work,helium is used as a working gas with an operating pressure range of 0.2 MPa to 1.0 MPa in order to study the performance of thermoacoustic refrigerator(TAR)which is fabricated using Poly-vinyl-Chloride(PvC).The parallel plate stacks with different porosity ratios have been considered to study the performance of *** temperature difference between the hot and cold heat exchanger and acoustic dynamic pressure were recorded by using Bruel and Kjaer data acquisition system under different operating *** effect of different operating parameters such as operating frequency(200 Hz to 600 Hz),cooling load(2 W to 10 W)and drive ratio(0.6%to 1.6%)have also been considered to study the performance of *** TAR also modeled in DeltaEC software and the results are compared with the experimental outcomes and found to be in good *** experimental results show that-2.1℃is the lowest temperature measured at cold heat exchanger by achieving the highest temperature difference of about 32.9℃.An improvement is around 36%as compared to that of previous experiments that used aluminium *** highest Coefficient of Performance(COP)and the Relative Coefficient of Performance(COPR)are found to be 2.024 and 0.217,respectively.

关键词： thermoacoustic refrigerator parallel plate stack porosity ratio temperature difference COP COPR

Joint effect of quasicrystalline icosahedral and L1_(2)-strucutred phases precipitation on the grain structure and mechanical properties of aluminum-based alloys

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Journal of Materials Science & Technology 2021年第28期87卷 196-206页

作者： A.G.Mochugovskiy N.Yu.Tabachkova M.Esmaeili Ghayoumabadi v.v.Cheverikin A.v.Mikhaylovskaya National University of Sciences and Technology“MISIS” 119049Leninskiy Ave.4MoscowRussia Prokhorov General Physics Institute of the Russian Academy of Sciences MoscowRussia

Dispersoid hardening is a key factor in increasing the recrystallization resistance and mechanical strength of non-heat treatable aluminum-based *** and Zr are the main elements that form dispersoids in commercial Al-based *** this work,the annealing-induced precipitation behavior,the grain structure,and the mechanical properties of Al-3.0 Mg-1.1 Mn and Al-3.0 Mg-1.1 Mn-0.25 Zr alloys were *** microstructure and the mechanical properties were significantly affected by annealing regimes after casting for both *** research demonstrated a possibility to form high-density distributed quasicrystalline-structured I-phase precipitates with a mean size of 29 nm during low-temperature annealing of as-cast *** manganese-bearing precipitates of I-phase increased recrystallization resistance and significantly enhanced the mechanical strength of the alloys *** estimated strengthening effect owing to I-phase precipitation was 150 *** to the formation of L1_(2)-structured Al3Zr dispersoids with a mean size of 5.7 nm,additional alloying with Zr increased yield strength by about 90 *** L1_(2)-phase strengthening effect was estimated through the dislocation bypass looping and shearing mechanisms.

关键词： Aluminum alloy Quasicrystals Dispersoid hardening Recrystallization Mechanical properties

Deuteron inelastic scattering on ^(6)Li and ^(7)Li nuclei within the three-body cluster model

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Chinese Physics C 2021年第1期45卷 286-296页

作者： M.v.Egorov v.I.Postnikov Federal State Unitary Enterprise"Russian Federal Nuclear"Center'Academician E.I.Zababakhin All-Russian Research Institute of Technical Physics SnezhinskChelyabinsk Region.Russia and Physics FacultyTomsk State UniversityLenina ave.36Tomsk 634050Russia National Research Nuclear University MEPhI MoscowRussia

The problem of the deuteron interaction with lithium nuclei,treated as a system of two coupled pointlike clusters,is formulated to calculate the cross sections of the d+Li *** d+Li reaction mechanism is described using the Faddeev theory for the three-body problem of deuteron-nucleus *** theory is slightly extended for calculation of the stripping processes ^6Li(d,p)^7Li,^7Li(d,p)^8 ,^6Li(d,n)^7 Be,and ^7Li(d,n)^8 Be,as well as fragmentation reactions yielding tritium,a-particles,and continuous neutrons and protons in the initial deuteron kineticenergy region Ed=0.5-20 *** phase shifts found for d+^6Li and d+^7Li elastic scattering,as part of the simple optic model with a complex central potential,were used to find the cross sections for the 6^Li(d,yM)^8 and ^7Li(d,yE1)^9 Be radiation *** three-body dynamics role is also summarized to demonstrate its significant influence within the d+^7Li system.

关键词： deuteron-Li Faddeev equation inelastic scattering cluster model

First Asian record of Panthera(Leo)fossilis(Mammalia,Carnivora,Felidae)in the Early Pleistocene of Western Siberia,Russia

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Integrative Zoology 2014年第4期9卷 517-530页

作者： Marina v.SOTNIKOvA Irina v.FORONOvA Geological Institute of Russian Academy of Sciences MoscowRussia v.S.Sobolev Institute of Geology and Mineralogy Siberian Branch of Russian Academy of SciencesNovosibirskRussia

A lion-like pantherine felid is described as Panthera(Leo)fossilis from the late Early Pleistocene sediments of the Kuznetsk Basin(Western Siberia,Russia).The find of *** first recorded in Asia considerably extends the current notion of the eastward expansion of the most ancient *** Siberian lion is geologically the oldest form and is dimensionally among the largest members of the group of fossil lions on the Eurasian conti*** known by mandibular remains only,it is readily distinguished from Panthera(Leo)spelaea by a heavy built mandibular corpus with rectangular profile in the cheek teeth area,a deep,well-outlined and narrow anterior section of the masseteric fossa,and a largeр4 supported by a big unreduced anterior *** Siberian lion shares these features with the European Middle Pleistocene *** and the American Late Pleistocene P.(Leo)atrox,which suggests their close *** originated from *** and was isolated in North America south of the Late Pleistocene ice *** explains why the American lion has retained more primitive features than the coeval Eurasian cave lion P.(L.)spelaea.

关键词： Early Pleistocene evolution Panthera fossilis relationships Western Siberia

Enthalpy of formation of quasicrystalline phase and ternary solid solutions in the Al-Fe-Cu system

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Rare Metals 2006年第5期25卷 608-613页

作者： I.A.Tomilin S.D.Kaloshkin v.v.Tcherdyntsev Moscow State Institute of Steel and Alloys (Technologycal University) 119049 Leninsky prosp.4MoscowRussia

Standard enthalpies of formation of quasicrystalline phase and the ternary solid solutions in the Al-Fe-Cu system and the intermetaUic compound FeAI were determined by the means of solution calorimetry. The quasicrystalline phase was prepared using two different methods. The first method （I） consisted of ball milling the mixture of powders of pure aluminum copper and iron in a planetary mill with subsequent compacting by hot pressing and annealing. The second method （Ⅱ） consisted of arc melting of the components in argon atmosphere followed by annealing. The latter method was used for preparing the compound FeAl and the solid solutions. The phases were identified using the XRD method. The enthalpy of the formation was determined for the quasicrystalline phase of the composition Al62Cu25.5Fe12.5 and the temary BCC solid solutions Al35Cu14Fe51, Al40Cu17Fe43, and Al50.4Cu19.6Fe30. The measured enthalpy of formation of the intermetallic compound FeAl is in good agreement with the earlier published data. The enthalpies of formation of the quasicrystalline phases prepared using two different methods are close to each other, namely, -22.7±3.4 （method I） and -21.3±2.1 （method Ⅱ） kJ/mol.

关键词： enthalpy of formation calorimetry quasicrystals Al-Fe-Cu

Design of Mg-Zn-Si-Ca casting magnesium alloy with high thermal conductivity

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Journal of Magnesium and Alloys 2020年第1期8卷 184-191页

作者： v.E.Bazhenov A.v.Koltygin M.C.Sung S.H.Park A.Yu.Titov v.A.Bautin S.v.Matveev M.v.Belov v.D.Belov K.v.Malyutin National University of Science and Technology“MISiS” Leninskiy pr.4Moscow 119049Russia LG Electronics Inc. Yeoui-daeroYeongdeungpo-gu.128LG Twin TowerSeoul 07336 Republic of Korea

Magnesium alloys are commonly used to produce lightweight *** most magnesium alloys exhibit low thermal conductivities,high thermal conductivities are needed for electronic *** this study,we attempted to develop new magnesium casting alloys with high thermal *** Mg-Zn-Si-Ca alloy compositions were chosen using CALPHAD(CALculation of PHAse Diagrams)calculations,and alloy samples were *** fluidity and hot-tearing resistance were *** results indicated that these properties were similar to those of AZ91 *** tests showed that high-pressure die casting could produce Mg-Zn-Si-Ca alloys possessing mechanical properties 1.5-3 times higher than those produced via sand *** alloy thermal conductivity was 126 W/mK at room *** corrosion rates of the as-cast samples in NaCl/water solutions were two times higher than that of AZ91.

关键词： Magnesium alloy Thermal conductivity Phase composition Corrosion rate Sand casting High-pressure die casting

Numerical Modelling of the Aeroelastic Behaviour and variable Loads for the Turbine Stage in 3D Transonic Flow

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Journal of Thermal Science 2005年第3期14卷 236-241页

作者： v.I. GNESIN L.v. KOLODYAZHNAYA R. RZADKOWSKI Department of Aerohydromechanics Institute of Mechanical Engineering Problems National Academy of Sciences of Ukraine 2/10 Pozharsky st. Kharkov 61046 Ukraine ProfessorDepartment of Aerohydromechanics Institute of Mechanical Engineering Problems National Academy of Sciences of Ukraine 2/10 Pozharsky st. Kharkov 61046 UkraineDepartment of Dynamics of Machines Institute of Fluid Flow Machinery Polish Academy of Sciences J. Fiszera st. 14 Gdansk 80 952 Poland

In this study presented the algorithm proposed involves the coupled solution of 3-D unsteady flow through a turbine stage and the dynamics problem for rotor-blade motion by the action of aerodynamic forces, without separating the outer and inner flow fluctuations. The partially integrated method involves the solution of the fluid and structural equations separately, but information is exchanged at each time step, so that solution from one domain is used as a boundary condition for the other domain. 3-D transonic gas flow through the stator and rotor blades in relative motion with periodicity on the whole annulus is described by the unsteady Euler conservation equations, which are integrated using the explicit monotonous finite-volume difference scheme of Godunov-Kolgan. The structural analysis uses the modal approach and a 3-D finite element model of a blade. A calculation has been done for the last stage of the steam turbine, under design and off-design regimes. It is shown that the amplitude-frequency spectrum of blade oscillations contains the high frequency harmonics, corresponding to the rotor moving past one stator blade pitch, and low frequency harmonics caused by blade oscillations and flow nonuniformity downstream from the blade row; moreover, the spectrum involves the harmonics which are not multiples of the rotation frequency.

关键词： turbine stage 3D unsteady flow blade oscillations