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Science China Chemistry 2020年第6期63卷 753-754页

作者： Artem A.Antonov Wen-Hua Sun konstantin P.Bryliakov Boreskov Institute of Catalysis Pr.Lavrentieva 5Novosibirsk 630090Russia Novosibirsk State University Pirogova 1Novosibirsk 630090Russia Key Laboratory of engineering Plastics and Beijing National Laboratory for Molecular Sciences Institute of ChemistryChinese Academy of SciencesBeijing 100190China CAS Research/education Center for excellence in Molecular Sciences University of Chinese Academy of SciencesBeijing 100049China

Since the milestone discovery of Ni(II)salicylaldiminate catalysts by Grubbs and co-workers[1],nickel(II)complexes with N,N-and N,O-donor ligands have strengthened their lead in the search for highly active platforms for olefins homo-and copolymerization with various co-monomers,including those with polar groups,to achieve polymers with precisely controlled microstructures[2,3].

关键词： discovery catalysts co-monomers

Cap snatch prevention:a novel approach to tackle influenza viruses

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Signal Transduction and Targeted Therapy 2023年第6期8卷 2435-2436页

作者： konstantin M.J.Sparrer Frank Kirchhoff Institute of Molecular Virology Ulm University Medical CenterUlmGermany

A recent study published in Science1 by Tsukamoto and colleagues shows that a derivative of tubercidin,a natural product from Streptomyces,selectively inhibits influenza A and B viruses(IAV and IBV,respectively).The compound targets the host RNA methyltransferase MTr1,and thus prevents viral“cap snatching”(Fig.1).These results may help to develop novel drugs that target viral host dependency factors and are thus less likely to induce viral resistance.

关键词： prevention influenza likely

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Asian Journal of Andrology 2014年第1期16卷 50-59页

作者： konstantin Svechnikov Jan-Bernd Stukenborg Iuliia Savchuck Olle Sider Department of Women's and Children's Health Paediatric Endocrinology Unit Karolinska Institutet and University Hospital Stockholm Sweden

During the past few decades, scientific evidence has been accumulated concerning the possible adverse effects of the exposure to environmental chemicals on the well-being of wildlife and human populations. One large and growing group of such compounds of anthropogenic or natural origin is referred to as endocrine-disrupting chemicals （eDCs）, due to their deleterious action on the endocrine system. This concern was first focused on the control of reproductive function particularly in males, but has later been expanded to include all possible endocrine functions. The present review describes the underlying physiology behind the cascade of developmental events that occur during sexual differentiation of males and the specific role of androgen in the masculinization process and proper organogenesis of the external male genitalia. The impact of the genetic background, environmental exposures and lifestyle factors in the etiology of hypospadias, cryptorchidism and testicular cancer are reviewed and the possible role of eDCs in the development of these reproductive disorders is discussed critically. Finally, the possible direct and programming effects of exposures in utero to widely use therapeutic compounds, environmental estrogens and other chemicals on the incidence of reproductive abnormalities and poor semen quality in humans are also highlighted.

关键词： endocrine disrupters male (in)fertility reproductive disorders testis testicular steroidogenesis

Low-frequency laboratory measurements of the elastic properties of solids using a distributed acoustic sensing system

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Journal of Rock Mechanics and Geotechnical engineering 2023年第9期15卷 2330-2338页

作者： Vassily Mikhaltsevitch Maxim Lebedev Roman Pevzner Alexey Yurikov konstantin Tertyshnikov Curtin University GPO Box U1987PerthWA 6845Australia Centre for Sustainable energy and Resources Edith Cowan University270 Joondalup DrJoondalupWA 6027Australia

In recent decades,low-frequency(LF)experiments based on the forced-oscillation(FO)method have become common practice in many rock physics laboratories for measuring the elastic and anelastic properties of ***,the use of the electronic displacement sensors in traditional acquisition systems of FO devices such as conventional capacitive transducers or strain gauges seriously limits both the efficiency and productivity of LF measurements,and,due to the limited contact area of the displacement sensors with a sample under test,increases the requirements for sample *** this paper,we present the first results obtained in the development of a new laboratory method elaborated to measure the elastic properties of *** method is a further development of the FO method where traditional data acquisition is replaced by acquisition based on fiber-optic distributed acoustic sensing(DAS)*** new method was tested in a laboratory study using two FO setups designed for measurements under uniaxial and confining *** study was carried out on a sample made from polymethyl methacrylate(PMMA)and an aluminium standard,first under uniaxial pressure at FO frequencies of 1,10,30,60 and 100 Hz,and then under confining pressure at an FO frequency of 1 *** uniaxial and confining pressures were equal to 10 MPa,and the strain in the PMMA sample in all measurements did not exceed 4×10^(-8).The performance of DAS acquisition was compared with the measurements conducted at a strain of 1×10^(-6) using the traditional FO method based on the use of semiconductor strain gauges and the ultrasonic *** results of the DAS measurements are in good agreement with the FO measurements carried out using semiconductor strain gauges and with the literature data.

关键词： elasticity and anelasticity Acoustic properties Fourier analysis Wave propagation

experimental study of a low-pressure hybrid RF discharge

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Plasma Science and Technology 2020年第5期22卷 70-82页

作者： elena KRALKINA Polina NeKLIUDOVA Vladimir PAVLOV konstantin VAVILIN Ilya ZADIRIeV and Chen ZHAO Physical electronics Department Faculty of PhysicsLomonosov Moscow State University119991 MoscowRussia

experimental study of the low-pressure hybrid RF discharge with both inductive and capacitive channels was carried out. The RF power unit consists of inductor(antenna) and capacitor plates connected in parallel to the same RF power source. A separating capacitor Csepis included into the circuit between the antenna ends and the lead connected to the discharge capacitor plate in order to prevent the closing of the capacitive circuit through direct current by inductor and to control the contribution of capacitive channel to discharge sustaining. It is shown that at low power of the RF power source, power coupling to the discharge mainly occurs through the capacitive channel. Increasing the power of the RF power source increases the power coupled in the inductive channel, electron density, and current flowing through the capacitive channel. This leads to increasing voltage drop on the separating capacitor and partial cutoff of the capacitive channel. At separating capacitance values below certain value(below 50 pF in the present experiments), the self-bias of the loaded plate of the discharge capacitor becomes positive indicating that the thickness of the electrode sheath of the loaded electrode decreases compared to thickness of the sheath of the grounded electrode. The thickness of the space-charge sheath of the grounded electrode decreases with increasing power coupled to the plasma. At separating capacitance below 50 pF, higher harmonics of the RF voltage and current are actively generated in the capacitive discharge channel. Increasing the separating capacitance leads to decreasing electron density, increasing effective electron temperature and more effective RF energy coupling to plasma due to increasing relative importance of the capacitive discharge channel.

关键词： radio-frequency discharge plasma e-mode H-mode

Change in carbonate budget and composition during subduction below metal saturation boundary

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Geoscience Frontiers 2023年第1期14卷 79-100页

作者： Anton Shatskiy Anton V.Arefiev konstantin D.Litasov Vernadsky Institute of Geochemistry and Analytical Chemistry Russian Academy of SciencesMoscow 119991Russia Vereshchagin Institute for High Pressure Physics Russian Academy of SciencesTroitskMoscow 108840Russia

It is generally accepted that carbonates can be subducted to the mantle depths,where they are reduced with iron metal to produce a *** this work,we found that this is not always the *** mantle carbonates from inclusions in diamonds show a wide range of cation compositions(Mg,Fe,Ca,Na,and K).Here we studied the reaction kinetics of these carbonates with iron metal at 6-6.5 GPa and 1000-1500℃.We found that the reduction of carbonate with Fe produces C-bearing species(Fe,Fe-C melt,Fe_(3)C,F e_(7)C_(3),C)and wüistite containing Na_(2)O,CaO,and *** reaction rate constants(k=△x^(2)/2t)are log-linear relative to 1/T and their temperature dependences are determined to be k_(MgcO_(3))(m^(2)/s)=4.37×10^(-3)exp[-251(kJ/mol)/RT]k_(caMg(CO_(3))2)(m^(2)/s)=1.48×10^(-3)exp[-264(kJ/mol)/RT]k_(cacO_(3))(m^(2)/s)=3.06×10^(-5)exp[-245(kJ/mol)/RT]and k_(Na_(2)cO_(3))(m^(2)/s)=1.88×10^(-10)exp[-155(kJ/mol)/RT].According to obtained results at least,45-70 vol%of carbonates preserve during subduction down to the 660-km discontinuity if no melting *** slab stagnation and warming,subsequent carbonate melting,and infiltration into the mantle saturated with iron metal are accompanied by a reduction of carbonate melt with *** established sequence of reactivity of carbonates:FeCO_(3)≥MgCO_(3)>CaMg(CO_(3))2>CaCO_(3)>>Na_(2)CO_(3),where K_(2)CO_(3)does not react at all with iron metal,implies that during reduction carbonate melt with Fe evolves toward *** above conclusions are consistent with the findings of carbonates in inclusions in diamonds from the lower mantle and high concentrations of alkalis,particularly K,in mantle carbonatite melts entrapped by diamonds from kimberlites and placers worldwide.

关键词： Carbonate Reduction of carbonate with Fe Reaction kinetics Carbonatite melt High-pressure experiment earth's mantle

experimental and ab initio study of Ba_(2)Na_(3)(B_(3)O_(6))_(2)F stability in the pressure range of 0–10 GPa

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International Journal of Minerals,Metallurgy and Materials 2023年第9期30卷 1846-1854页

作者： Nursultan e.Sagatov Tatyana B.Bekker Yulia G.Vinogradova Alexey V.Davydov Ivan V.Podborodnikov konstantin D.Litasov Sobolev Institute of Geology and Mineralogy Siberian Branch of Russian Academy of SciencesNovosibirsk 630090Russia Department of Geology and Geophysics Novosibirsk State UniversityNovosibirsk 630090Russia Research and Development Department Novosibirsk State University of ArchitectureDesign and Arts(NSUADA)Novosibirsk 630099Russia Vereshchagin Institute for High Pressure Physics Russian Academy of SciencesTroitsk 108840Russia Fersman Mineralogical Museum Russian Academy of SciencesMoscow 119071Russia

Both numerical and experimental studies of the stability and electronic properties of barium–sodium metaborate Ba_(2)Na_(3)(B_(3)O_(6))_(2)F(P63/m) at pressures up to 10 GPa have been carried out. electronic-structure calculations with HSe06 hybrid functional showed that Ba_(2)Na_(3)(B_(3)O_(6))_(2)F has an indirect band gap of 6.289 eV. A numerical study revealed the decomposition of Ba_(2)Na_(3)(B_(3)O_(6))_(2)F into the BaB_(2)O_(4),Na BO_(2), and NaF phases above 3.4 GPa at 300 K. Subsequent high-pressure high-temperature experiments performed using ‘Discoverer-1500’DIA-type apparatus at pressures of 3 and 6 GPa and temperature of 1173 K confirmed the stability of Ba_(2)Na_(3)(B_(3)O_(6))_(2)F at 3 GPa and its decomposition into BaB_(2)O_(4), NaBO_(2), and NaF at 6 GPa, which was verified by energy-dispersive X-ray analysis and Raman spectroscopy. The observed Raman bands of the Ba_(2)Na_(3)(B_(3)O_(6))_(2)F phase were assigned by comparing the experimental and calculated spectra. The experimental Raman spectra of decomposition reaction products obtained at 6 GPa suggest the origin of a new high-pressure modification of barium metaborate BaB_(2)O_(4).

关键词： density functional theory phase stability borate high pressure Raman spectroscopy

Dielectric properties of BaMg_(1/3)Nb_(2/3)O_(3) doped Ba_(0.45)Sr_(0.55)TiO_(3) thin films for tunable microwave applications

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Journal of Advanced Dielectrics 2015年第4期5卷 21-29页

作者： Fikadu Alema konstantin Pokhodnya Center for Nanoscale Science and engineering North Dakota State University Fargo ND 58108USA Agnitron Technology Incorporated eden Prairie MN 55344USA

Ba(Mg_(1/3)Nb_(2/3))O_(3)(BMN)doped and undoped B_(0.45)Sr_(0.55)TiO_(3)(BST)thin films were deposited via radio frequency magnetron sputtering on PUTiO_(2)/SiO_(2)/Al_(2)O_(3) *** surface morphology and chemical state analyses of the films have shown that the BMN doped BST film has a smoother surface with reduced oxygen vacancy,resulting in an improved insulating properties of the BST *** tunability,loss,and leakage current(LC)of the undoped and BMN doped BST thin flms were *** BMN dopant has remarkably reduced the dielectric loss(~38%)with no significant effect on the tunability of the BST film,leading to an increase in figure of merit(FOM).This is attributed to the opposing behavior of large Mg2+whose detrimental effect on tunability is partially compensated by small Nb5+as the two substitute Ti4+in the *** coupling between Mg″_(Ti)and V_(o)charged defects suppresses the dielectric loss in the film by cutting electrons from hopping between Ti *** LC of the films was investigated in the temperature range of 300-450K.A reduced LC measured for the BMN doped BST film was correlated to the formation of defect dipoles from Mg″_(Ti),V_(o)and Nb_(Ti) charged *** carrier transport properties of the films were analyzed in light of Schottky thermionic emission(Se)and Poole-Frenkel(PF)enmission *** result indicated that while the carrier transport mechanism in the undoped film is interface limited(Se),the conduction in the BMN doped film was dominated by bulk processes(PF).The change of the conduction mechanism from Se to PF as a result of BMN doping is atributed to the presence of uncoupled Nb_(Ti) stting as a positive trap center at the shallow donor level of the BST.

关键词： Barium strontium titanate sputtering frreletric thin film tunability leakage current permitivity loss figure of merit defect dipole

PHOTOACOUSTIC GeNeRATION OF FOCUSeD QUASI-UNIPOLAR PReSSURe PULSeS

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Journal of Innovative Optical Health Sciences 2010年第4期3卷 247-253页

作者： konstantin MASLOV HAO F.ZHANG LIHONG V.WANG Optical Imaging Laboratory Department of Biomedical Engineering Washington University in St.Louis St.LouisMissouri 63130USA Department of electrical engineering and Computer Science University of Wisconsin-Milwaukee Milwaukee Wisconsin 53201USA

The photoacoustic effect was employed to generate short-duration quasi-unipolar acoustic pressure pulses in both planar and spherically focused *** the focal region,the temporal profile of a pressure pulse can be approximated by the first derivative of the temporal profile near the front transducer surface,with a time-averaged value equal to *** approximation agreed with experimental results acquired from photoacoustic transducers with both rigid and free *** a free boundary,the acoustic pressure in the focal region is equal to the sum of a positive pressure that follows the spatial profile of the optical energy deposition in the medium and a negative pressure that follows the temporal profile of the laser pulse.

关键词： Photoacoustics optoacoustics ultrasound generation unipolar pulse

The magnetic states and Labyrinth ordering in 2D lattices of ising spins with RKKY Interaction

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International Journal of Modeling, Simulation, and Scientific Computing 2015年第2期6卷 40-48页

作者： konstantin Nefedev Valery Belokon Vitalii Kapitan Olga Dyachenko The Department of Computer System The School of Natural Sciences Far eastern Federal University 8Sukhanova St.690950VladivostokRussian Federation Institute of Applied Mathematics Far eastern Branch Russian Academy of Science 7 Radio St. 690041VladivostokRussian Federation The Department of Theoretical and experimental Physics The School of Natural Sciences Far eastern Federal University 8Sukhanova St.690950VladivostokRussian Federation The Department of Physics of Low-Dimensional Structures The School of Natural Sciences Far eastern Federal University 8Sukhanova St.690950VladivostokRussian Federation The Department of General Physics The School of Natural Sciences Far eastern Federal University 8Sukhanova St.690950VladivostokRussian Federation

The numerical simulation of 2D simple square lattice of Ising superspins,that interact via the Ruderman–Kittel–Kasuya–Yosida(RKKY)exchange interaction is *** is found,that at low temperatures in the researched systems predominantly realized labyrinth domain *** modeled image of magnetization distribution does not coincide with the image of energy *** loops of the samples and labyrinth domain structures similarly obtained by Monte Carlo method,are also observed in physical experiments.

关键词： Ising model long-range interaction magnetic states Monte Carlo simulation