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Telluric iron assemblages as a source of prebiotic phosphorus on the early Earth:Insights from Disko Island,Greenland

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Geoscience Frontiers 2024年第5期15卷 415-429页

作者： Oleg S.Vereshchagin Maya O.Khmelnitskaya Larisa V.Kamaeva natalia S.Vlasenko Dmitrii V.Pankin vladimir n.bocharov Sergey n.Britvin Saint Petersburg State University University Embankment 7-9St.Petersburg 199034Russia Udmurt Federal Research Center Ural BranchRussian Academy of SciencesIzhevsk 426067Russia nanomaterial Research Center Kola Science CentreRussian Academy of SciencesApatity 184209Russia

Phosphorus is one of the key elements,which determined the emergence of primordial life on our *** source of prebiotic phosphorus was most likely to be easily soluble compounds containing phosphorus in the negative form of oxidation(e.g.,phosphides).The present paper is the first thorough investigation of phosphide-bearing mineral assemblages confined to telluric(terrestrial)native iron from volcanic rocks of Disko Island,*** speciation in given assemblages varies from the solid solution in native iron(up to 0.3 wt.%P),different phosphides–schreibersite Fe_(3)P,nickelphosphide ni_(3)P,barringerite Fe_(2)P,and phosphates,including fluorapatite,anhydrous Fe-na phosphates,phosphoran olivine and pyroxene(up to 1 wt.%P).The diversity of observed phosphorus speciation can be explained by the steep changes of redox conditions during subsurface crystallization of iron-phosphide-bearing *** on the available data on likely redox conditions on the early Earth,we hypothesize that reactive prebiotic phosphorus may have originated from shallow crustal rocks.

关键词： Prebiotic phosphorus native iron Phosphide Reduced mineral assemblages

Study of asphaltene reaggregation in toluene/heptane mixture by dynamic and static light scattering

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Petroleum Research 2024年第1期9卷 48-54页

作者： vladimir n.Kuryakov Oil and Gas Research Institute of RAS(OGRI RAS) Gubkina Str.3119333MoscowRussian Federation

This paper presents the study of the effect of multiple ultrasonic impacts on submicron asphaltene aggregates in a toluene/heptane solution,conducted with dynamic light scattering *** objects of the study were four samples of asphaltenes obtained from four different *** all samples,the change in the average size of the asphaltene submicron aggregates with time was measured after the addition of a precipitant(heptane)to a solution of asphaltenes in toluene at an amount above the threshold *** aggregates formed in solution after the addition of the precipitant and were subjected to ultrasonic treatment,which led to the destruction of the asphaltene *** of destroyed asphaltenes was *** kinetics of this aggregation were similar to the kinetics of aggregation of asphaltenes after the addition of a *** iterations of asphaltene aggregate destruction in the sample led to a significant change in the kinetics of aggregation:the growth of aggregates slowed and stabilized at a size of approximately 200 nm and 30 nm for the different studied samples.

关键词： Asphaltenes Aggregation Sonication Dynamic light scattering Re-aggregation Colloidal stability Resins

A new Mantispid-Like Species of Rhachiberothinae (neuroptera:Berothidae) from Baltic Amber,with a Critical Review of the Fossil Record of the Subfamily

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Acta Geologica Sinica(English Edition) 2010年第4期84卷 655-664页

作者： vladimir n.MAKARKIn Janusz KUPRYJAnOWICZ Institute of Biology and Soil Sciences Far Eastern Branch of the Russian Academy of SciencesVladivostokRussia Institute of Biology University of BialystokBialystokPoland Museum of the Earth the Polish Academy of SciencesWarsawPoland

Whalfera wiszniewskii sp. nov. is described from the Late Eocene Baltic amber. The genus Whalfera is considered as the only fossil genus confidently assigned to the Rhachiberothinae. Others previously placed in this subfamily belong to Paraberothinae （except perhaps for Oisea）. The Late Eocene/present Rhachiberothinae and the Cretaceous Paraberothinae are considered to be the subfamilies of Berothidae.

关键词： neuroptera Berothidae Rhachiberothinae Paraberothinae Mantispidae Symphrasinae

Image potential states mediated STM imaging of cobalt phthalocyanine on naCl/Cu(100)

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Chinese Physics B 2016年第3期25卷 314-318页

作者：郭秦敏秦志辉黄敏 vladimir n.Mantsevich 曹更玉 State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Wuhan Institute of Physics and MathematicsChinese Academy of Sciences Faculty of Physics Moscow State University

The adsorption and electronic properties of isolated cobalt phthalocyanine （CoPc） molecule on an ultrathin layer of naC1 have been investigated. High-resolution STM images give a detailed picture of the lowest unoccupied molecular orbital （LUMO） of an isolated CoPc. It is shown that the naC1 ultrathin layer efficiently decouples the interaction of the molecules from the underneath metal substrate, which makes it an ideal substrate for studying the properties of single molecules. Moreover, strong dependence of the appearance of the molecules on the sample bias in the region of relatively high bias （〉 3.1 V） is ascribed to the image potential states （IPSs） of naCI/Cu（100）, which may provide us with a possible method to fabricate quantum storage devices.

关键词： image potential states naC1 ultrathin layer CoPc scanning tunneling microscopy

Role of the Rossiter-McLaughlin effect in the study of close binaries

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Research in Astronomy and Astrophysics 2019年第3期19卷 21-30页

作者： Galina n.Dryomova vladimir V.Dryomov Russian Federal nuclear Centre

This paper is devoted to binary stars belonging to the class of eclipsing-variable *** and spectroscopic analysis of eclipses allows us to determine geometric parameters of the orbit and physical characteristics of stellar components as well as inclinations of stellar equators to the orbital plane. Estimations of inclinations can be obtained from measurement of the Rossiter-McLaughlin effect, which is discussed using examples of some eccentric binaries with an anomalous apsidal effect. Our task is to find the complete spectrum of solutions of the equation of apsidal motion, depending on the inclinations of the polar axes of the components to the orbital one for these systems, based on their individual spectroscopic and photometric observational data. The matrix of solutions allows us to select those pairs of polar inclinations that provide agreement with the observational apsidal period.

关键词： Rossiter-McLaughlin effect: eclipsing-variable stars apsidal effect individual binaries: AI Hya,nY Cep,EW Ori,DI Her,AS Cam

Relaxation of Mechanical Stress in Poly(vinyl alcohol) Cryogels of Different Compositions

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Chinese Journal of Polymer Science 2023年第3期41卷 442-447,I0010页

作者： vladimir n.Manzhai Maria S.Fufaeva Ekaterina S.Kashlach Institute of Petroleum Chemistry of the Siberian Branch of the Russian Academy of Sciences Tomsk 634055Russia

The study presents the experimental results of measurements of the relaxation time of cryogels formed from various colloid-dispersed systems based on a poly(vinyl alcohol) aqueous *** is shown that the value of relaxation time,which characterizes the relationship between the viscosity and elasticity of real bodies,describes the rheological properties of materials more objectively than the traditional assessment of their physical and mechanical characteristics only by the elasticity modulus of the samples.

关键词： Cryogel Relaxation processes Viscoelasticity Rheological properties

Role of Electromagnetic Fluctuations in Organic Electronics

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Journal of Electronic Science and Technology 2020年第1期18卷 52-58页

作者： vladimir M.Mostepanenko Elena n.Velichko Maksim Aleksandrovich Baranov Institute of Physics Nanotechnology and TelecommunicationsPeter the Great St.Petersburg Polytechnic UniversitySt.Petersburg 195251 Central Astronomical Observatory at Pulkovo of Russian Academy of Sciences St.Petersburg 196140

Thin organic films find expanding applications in electronic and optoelectronic devices, biotechnology,food packing, and for many other purposes. Among other factors, the stability of films with a thickness below a micrometer is determined by the zero-point and thermal fluctuations of the electromagnetic field. These fluctuations result in the van der Waals and Casimir free energy and forces between a film and a substrate. The fluctuationinduced force may be both attractive and repulsive making the film either more or less stable, respectively. Here, we review recently obtained results for the Casimir free energy of both freestanding and deposited on the metallic and dielectric substrates peptide films. We also perform computations for the free energy of the peptide films deposited on a silica glass substrate in the region of parameters where this free energy vanishes. Possible applications of the obtained results are discussed.

关键词： Casimir free energy organic electronics peptide film

Analytical solution for a strong free-surface water vortex describing flow in a full-scale gravitational vortex hydropower system

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Water Science and Engineering 2021年第1期14卷 72-79页

作者： vladimir Joel Alzamora Guzman Julie Anne Glasscock Energy Research Group Kadagaya Research Centre for Appropriate TechnologyJunin 12866Peru

Strong free-surface water vortices are found throughout industrial hydraulic systems used for water treatment,flow regulation,and energy *** models using the volumetric flow rate as a model input have generally been semi-empirical,and have tended to have some limitations in terms of the design of practical hydropower *** this study,an analytical model of a strong free-surface water vortex was *** model only requires the water head and geometric parameters as its inputs and calculates the maximum volumetric flow rate,aircore diameter,and rotational *** experimental depthedischarge data from a full-scale gravitational vortex hydropower system,unavailable in the relevant literature,were obtained,and the simulated results showed excellent agreement with the experimental *** data could be used to verify similar models using laboratory-scale physical models in order to investigate the scaling *** contrast to previous models,this model does not assume a constant average velocity across the vortex radius and allows precise calculation of the resultant velocity ***,this model presents advantages in turbine design for energy generation systems.

关键词： Gravitational vortex Velocity measurements Scalability Analytical model Microhydropower

Generation of dual and quad‑optical frequency combs in the injected radiation free mode‑locked frequency‑shifted feedback laser

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Frontiers of Optoelectronics 2023年第3期16卷 43-56页

作者： Sergey n.Mantsevich Ekaterina I.Kostyleva Andrey n.Danilin vladimir S.Khorkin Physics Department M.V.Lomonosov Moscow State UniversityMoscow 119991Russia Russian Quantum Center(RQC) Skolkovo 143026Russia

The results of an optoelectronic system—frequency-shifted feedback(FSF)laser experimental examination are *** considered FSF laser is seeded only with optical amplifer spontaneous emission(ASE)and operates in the mode-locked regime,whereby the output radiation is sequence of short pulses with a repetition rate determined by the delay time in its optical feedback *** the frequency domain,the spectrum of such a pulse sequence is an optical frequency comb(OFC).These OFCs we call *** consider the possibility of tunable acousto-optic(AO)dual and quad-comb frequency spacing downconversion in the FSF laser seeded with ASE and operating in the mode-locked *** examined system applies a single frequency shifting loop with single AO tunable flter as the frequency shifter that is fed with several radio frequency signals *** initial OFCs with frequency spacing of about 6.5 MHz may be obtained in the wide spectral range and their width,envelope shape and position in the optical spectrum may be *** dual-combs are obtained with a pair of initial OFCs aroused by two various ultrasound waves in the acousto-optic tunable flter(AOTF).The dual-combs frequency spacing is determined by the frequency diference of the signals applied to the AOTF piezoelectric transducer and can be tuned *** quad-combs are obtained with three initial OFCs,forming a pair of dual-combs,appearing when three ultrasound frequencies feed the AOTF *** quad-combs frequency spacing is defned by the diference between the frequency spacing of ***-combs with more than 5000 spectral lines and tunable frequency spacing are *** successive frequency downconversion gives the possibility to reduce the OFC frequency spacing form several MHz for initial OFC to tens of kHz for quad-combs.

关键词： Frequency-shifted feedback laser Optical frequency combs Acousto-optics Dual-combs Quad-combs