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

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

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Smad7 dependent expression signature highlights BMP2 and HK2 signaling in HSC transdifferentiation

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World Journal of Gastroenterology 2010年第41期16卷 5211-5224页

作者： Bernd Denecke Lucia Wickert Loredana Ciuclan Steven Dooley Nadja M meindl-Beinker Yan Liu Interdisciplinary Centre for Clinical Research (IZKF) Aachen RWTH Aachen University 52074 Aachen Germany Institute of Clinical Chemistry and Pathobiochemistry of RWTH-University Hospital Department of Biology Babes-Bolyai University 400084 Cluj-Napoca Romania Molecular Hepatology Alcohol Induced Diseases Department of Medicine Ⅱ Medical Faculty Mannheim University of Heidelberg 68167 Mannheim

AIM: To analyse the influence of Smad7, antagonist of transforming growth factor (TGF)-β canonical signaling pathways on hepatic stellate cell (HSC) transdifferentia-tion in detail. METHODS: We systematically analysed genes regulated by TGF-β/Smad7 in activated HSCs by microarray analy-sis and validated the results using real time polymerase chain reaction and Western blotting analysis. RESULTS: We identif ied 100 known and unknown tar-gets underlying the regulation of Smad7 expression and delineated 8 gene ontology groups. Hk2, involved in glycolysis, was one of the most downregulated proteins, while BMP2, activator of the Smad1/5/8 pathway, was extremely upregulated by Smad7. However, BMP2 de-pendent Smad1 activation could be inhibited in vitro by Smad7 overexpression in HSCs. CONCLUSION: We conclude (1) the existence of a tight crosstalk of TGF-β and BMP2 pathways in HSCs and (2) a Smad7 dependently decreased sugar metabolism ameliorates HSC activation probably by energy with-drawal.

关键词： Transforming growth factor-β Smad7 Hepatic stellate cell Gene regulation Glucose metabolism BMP2

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Investigating Energy Prosumer Behaviour in Crowd Energy Using an Interactive Model/Diorama

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Journal of Electronic Science and Technology 2018年第4期16卷 341-350页

作者： Christian Ritzel anton Sentic the international institute of management in technology University of Fribourg Fribourg 1700Switzerland

Smart living labs such as the one located in Fribourg(Switzerland) focus on improving wellbeing and furthering knowledge related to building the district of the future on a technical and social level. Therefore, smart living labs represent an experimental platform/space where sustainable production and consumption strategies can be tested in a protected environment. A significant change in the socioeconomic production and consumption sphere can be expected by the rise of the so-called energy prosumer. Accordingly, this article presents an interactive model for the experimental investigation of energy prosumer behavior. In this context, two potential experiments on investment and trade decisions are briefly outlined. Since(behavioral and economic) experiments are usually conducted under controlled conditions in experimental labs involving mainly undergraduate students, the presented interactive model is flexible and mobile, providing the advantage to conduct experiments nearly everywhere involving everyday citizens.

关键词： Crowd energy decentralised energy systems experiments prosumers smart grid

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EXPONENTIAL INTEGRATORS FOR STOCHASTIC SCHRODINGER EQUATIONS DRIVEN BY ITO NOISE

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Journal of Computational Mathematics 2018年第2期36卷 276-309页

作者： Rikard anton David Cohen Department of Mathematics and Mathematical Statistics Umea University SE-901 87 Umea Sweden Department of Mathematics University of Innsbruck A 6020 Innsbruck Austria

We study an explicit exponential scheme for the time discretisation of stochastic SchrS- dinger Equations Driven by additive or Multiplicative It6 Noise. The numerical scheme is shown to converge with strong order 1 if the noise is additive and with strong order 1/2 for multiplicative noise. In addition, if the noise is additive, we show that the exact solutions of the linear stochastic Sehr6dinger equations satisfy trace formulas for the expected mass, energy, and momentum （i. e., linear drifts in these quantities）. Furthermore, we inspect the behaviour of the numerical solutions with respect to these trace formulas. Several numerical simulations are presented and confirm our theoretical results.

关键词： Stochastic partial differential equations Stochastic SchrSdinger equations,Numerical methods Geometric numerical integration Stochastic exponential integrators,Strong convergence Trace formulas.

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Drosophila melanogaster brain invasion pathogenic Wolbachia in central nervous system of the fly

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Insect Science 2016年第2期23卷 253-264页

作者： anton Strunov Elena Kiseleva Institute of Cytology and Genetics Siberian Branch of the Russian Academy of Sciences Prospekt Lavrentyeva 10 Novosibirsk 630090Russia

The pathogenic Wolbachia strain wMelPop rapidly over-replicates in the brain, muscles, and retina of Drosophila melanogaster, causing severe tissue degeneration and premature death of the host. The unique features of this endosymbiont make it an excellent tool to be used for biological control of insects, pests, and vectors of human diseases. To follow the dynamics of bacterial morphology and titer in the nerve cells we used transmission electron microscopy of 3-d-old female brains. The neurons and glial cells from central brain of the fly had different Wolbachia titers ranging from single bacteria to large accumulations, tearing cell apart and invading extracellular space. The neuropile regions of the brain were free of wMelPop. Wolbaehia tightly interacted with host cell organelles and underwent several morphological changes in nerve cells. Based on different morphological types of bacteria described we propose for the first time a scheme of wMelPop dynamics within the somatic tissue of the host.

关键词： bacterial morphology dynamics brain Drosophila melanogaster electronmicroscopy pathogenic endosymbiont Wolbachia strain wMelPop

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Trajectory correction for lunar flyby transfers to libration point orbits using continuous thrust

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Astrodynamics 2022年第3期6卷 285-300页

作者： Yi Qi anton de Ruiter School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China Department of Aerospace Engineering Ryerson UniversityTorontoON M5B 2K3Canada

Trajectory corrections for lunar flyby transfers to Sun–Earth/Moon libration point orbits(LPOs)with continuous thrusts are investigated using an ephemeris *** lunar flyby transfer has special geometrical and dynamical structures;therefore,its trajectory correction strategy is considerably different from that of previous studies and should be specifically *** this paper,we first propose a control strategy based on the backstepping technique with a dead-band scheme using an ephemeris *** initial error caused by the launch time error is *** the perturbed transfers significantly diverge from the reference transfers after the spacecraft passes by the Moon,we adopt two sets of control parameters in two portions before and after the lunar flyby,***,practical constraints owing to the navigation and propellant systems are introduced in the dynamical model of the trajectory *** a prograde type 2 orbit as an example,numerical simulations show that our control strategy can efficiently address trajectory corrections for lunar flyby transfers with different practical *** addition,we analyze the effects of the navigation intervals and dead-band scheme on trajectory ***,trajectory corrections for different lunar flyby transfers are depicted and compared.

关键词： libration point orbit trajectory correction Earth-Moon system continuous thrust backstepping technique

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Analyzing the energy intensity and greenhouse gas emission of Canadian oil sands crude upgrading through process modeling and simulation

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Frontiers of Chemical Science and Engineering 2014年第2期8卷 212-218页

作者： anton ALVAREZ-MAJMUTOV Jinwen CHEN Natural Resources Canada CanmetENERGY One Oil Patch Drive Devon AB T9G 1A8 Canada

This paper presents an evaluation of the energy intensity and related greenhouse gas/CO2 emissions of integrated oil sands crude upgrading processes. Two major oil sands crude upgrading schemes currently used in Canadian oil sands operations were investigated： cokingbased and hydroconversion-based. The analysis, which was based on a robust process model of the entire process, was constructed in Aspen HYSYS and calibrated with representative data. Simulations were conducted for the two upgrading schemes in order to generate a detailed inventory of the required energy and utility inputs： process fuel, steam, hydrogen and power. It was concluded that while hydroconversion-based scheme yields considerably higher amount of synthetic crude oil （SCO） than the cokerbased scheme （94 wt-% vs. 76 wt-%）, it consumes more energy and is therefore more CO2-intensive （413.2kg CO2/m3sco vs. 216.4kg CO2/m^3sco）. This substantial difference results from the large amount of hydrogen consumed in the ebullated-bed hydroconverter in the hydroconversion-based scheme, as hydrogen production through conventional methane steam reforming is highly energy-intensive and therefore the major source of CO2 emission. Further simulations indicated that optimization of hydroconverter operating variables had only a minor effect on the overall CO2 emission due to the complex trade-off effect between energy inputs.

关键词： Oil sands crude upgrading hydroconversion,process modeling greenhouse gas emissions

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Analysis of the Water Film Behavior and its Breakup on Profile using Experimental and Numerical Methods

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Journal of Thermal Science 2014年第4期23卷 325-331页

作者： Tomas MUZIK Pavel SAFARIK antonín TUCEK TechSoft Engineering Na Pankraci 2614000 PragueCzech Republic CTU in Prague Department of Fluid Dynamics and ThermodynamicsTechnicka 416607 PragueCzech Republic

This paper deals with the description of water film behaviour on the airfoil NACA0012 using experimental and numerical methods. Properties of the water film on the profile and its breakup into droplets behind the profile are investigated in the aerodynamic tunnel and using CFD methods. The characteristic parameters of the water film, like its thickness and shape for different flow modes are described. Hereafter are described droplets drifted by the air, which water film is broken behind the profile.

关键词： NACA0012 profile water film droplets breakup CFD

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Exact Computation of the Topology and Geometric Invariants of the Voronoi Diagram of Spheres in 3D

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Journal of Computer Science & Technology 2013年第2期28卷 255-266页

作者： Franois anton Darka Mioc Marcelo Santos Research Division of Geodesy National Space Institute Technical University of Denmark Department of Geodesy and Geomatics Engineering University of New Brunswick

In this paper, we are addressing the exact the Voronoi diagram of spheres using Wu＇s algorithm. computation of the Delaunay graph （or quasi-triangulation） and Our main contributions are first a methodology for automated derivation of invariants of the Delaunay empty circumsphere predicate for spheres and the Voronoi vertex of four spheres, then the application of this methodology to get all geometrical invariants that intervene in this problem and the exact computation of the Delaunay graph and the Voronoi diagram of spheres. To the best of our knowledge, there does not exist a comprehensive treatment of the exact computation with geometrical invariants of the Delaunay graph and the Voronoi diagram of spheres. Starting from the system of equations defining the zero-dimensional algebraic set of the problem, we are applying Wu＇s algorithm to transform the initial system into an equivalent Wu characteristic （triangular） set. In the corresponding system of algebraic equations, in each polynomial （except the first one）, the variable with higher order from the preceding polynomial has been eliminated （by pseudo-remainder computations） and the last polynomial we obtain is a polynomial of a single variable. By regrouping all the formal coefficients for each monomial in each polynomial, we get polynomials that are invariants for the given problem. We rewrite the original system by replacing the invariant polynomials by new formal coefficients. We repeat the process until all the algebraic relationships （syzygies） between the invariants have been found by applying Wu＇s algorithm on the invariants. Finally, we present an incremental algorithm for the construction of Voronoi diagrams and Delaunay graphs of spheres in 3D and its application to Geodesy.

关键词： Voronoi diagram of spheres Delaunay graph of spheres Wu's method invariant characteristic set

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Detecting patterns of climate change in long-term forecasts of marine environmental parameters

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International Journal of Digital Earth 2020年第5期13卷 567-585页

作者： Gianpaolo Coro Pasquale Pagano anton Ellenbroek Istituto di Scienza e Tecnologie dell’Informazione“A.Faedo”–CNR PisaItaly b Food and Agriculture Organization of the United Nations(FAO) RomeItaly

Forecasting environmental parameters in the distant future requires complex modelling and large computational *** to the sensitivity and complexity of forecast models,long-term parameter forecasts(*** to 2100)are uncommon and only produced by a few organisations,in heterogeneous formats and based on different assumptions of greenhouse gases ***,data mining techniques can be used to coerce the data to a uniform time and spatial representation,which facilitates their use in many *** this paper,streams of big data coming from AquaMaps and NASA collections of 126 long-term forecasts of nine types of environmental parameters are processed through a cloud computing platform in order to(i)standardise and harmonise the data representations,(ii)produce intermediate scenarios and new informative parameters,and(iii)align all sets on a common time and spatial *** series crosscorrelation applied to these aligned datasets reveals patterns of climate change and similarities between parameter trends in 10 marine *** results highlight that(i)the Mediterranean Sea may have a standalone‘response’to climate change with respect to other areas,(ii)the Poles are most representative of global forecasted change,and(iii)the trends are generally alarming for most oceans.

关键词： Climate change environmental parameters forecasting environmental parameters time series ecological modelling species distribution modelling AquaMaps NASA Earth Exchange

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