High-performance and durable alcohol-fueled symmetrical solid oxide fuel cell based on ferrite perovskite electrode

This work is supported by the NSFC (grant No. 51702264; 41371275) and National Key Research and Development Program of China (grant No. 2018FYD0200701) and research funding for central universities (XDJK2020B066). C.N. also thanks to the award of Chongqing Bayu Young Scholar from Chongqing Teaching Committee and Funding for Oversea Returnees, while J.N. thanks to the support from Chongqing Yingcai Talent.A solid oxide fuel cell utilizing bio-fuels such as methanol and ethanol could provide a carbon–neutral electricity generation and facilitate its applications in transport or stationary power unit. Herein, Ce4+ doping in SrFe0.95Ni0.05O3 imparts FeNi3 exsolution and CeO2 precipitation in a reducing condition, contributing to the fuel reforming, C-C bond cleavage and coke consumption in the anode chamber. The ferrite perovskites are stable in ethanol/steam at 800 °C, whereas they are unstable in ethanol vapor with the high C fugacity inducing the formation of Fe0 and carbides. However, the Ce0.2Sr0.8Fe0.95Ni0.05O3 anode maintains mostly the perovskite and is free from coke after the 300 h’ operation under C2H5OH fuel at 0.5 V or 0.7 V because of the dynamic balance between the carbon deposition and consumption since an operation for 10 h shows a clear carbon deposition. A maximum power density of 0.58 W cm−2 and a polarization resistance of 0.21 Ω cm2 at 800 °C can be obtained for the symmetrical solid oxide fuel cell with identical Ce0.2Sr0.8Fe0.95Ni0.05O3 cathode and anode under an ethanol fuel. The results demonstrate that the reversible and stable SrFeO3 with Ce/Ni co-doping has a bright prospect for alcohol fuel oxidation.PostprintPostprintPeer reviewe

Multizone decomposition for simulation of time-dependent problems using the multiquadric scheme

AbstractThis paper discusses the application of the multizone decomposition technique with multiquadric scheme for the numerical solutions of a time-dependent problem. The construction of the multizone algorithm is based on a domain decomposition technique to subdivide the global region into a number of finite subdomains. The reduction of ill-conditioning and the improvement of the computational efficiency can be achieved with a smaller resulting matrix on each subdomain. The proposed scheme is applied to a hypothetical linear two-dimensional hydrodynamic model as well as a real-life nonlinear two-dimensional hydrodynamic model in the Tolo Harbour of Hong Kong to simulate the water flow circulation patterns. To illustrate the computational efficiency and accuracy of the technique, the numerical results are compared with those solutions obtained from the same problem using a single domain multiquadric scheme. The computational efficiency of the multizone technique is improved substantially with faster convergence without significant degradation in accuracy

Partial wave contributions to the antikaon potential at finite momentum

The momentum dependence of the antikaon optical potential in nuclear matter is obtained from a microscopic and self-consistent calculation using the meson-exchange J\"ulich $\bar{K}N$ interaction. Two self-consistent schemes are discussed, which would lead to substantially different predictions for the width of ${\bar K}$ nuclear bound states. The effect of higher partial waves of the $\bar{K}N$ interaction, beyond the L=0 component, is studied and found to have moderate but non-negligible effects on the ${\bar K}$ nuclear potential at zero momentum. At momenta as large as 500 MeV/c, relevant in the analysis of heavy-ion collisions, the higher partial partial waves modify the ${\bar K}$ optical potential by nearly a factor of two.Comment: 20 pages, 7 figure

Multi-Choice Minority Game

The generalization of the problem of adaptive competition, known as the minority game, to the case of $K$ possible choices for each player is addressed, and applied to a system of interacting perceptrons with input and output units of the type of $K$-states Potts-spins. An optimal solution of this minority game as well as the dynamic evolution of the adaptive strategies of the players are solved analytically for a general $K$ and compared with numerical simulations.Comment: 5 pages, 2 figures, reorganized and clarifie

Structural Routability of n-Pairs Information Networks

Information does not generally behave like a conservative fluid flow in communication networks with multiple sources and sinks. However, it is often conceptually and practically useful to be able to associate separate data streams with each source-sink pair, with only routing and no coding performed at the network nodes. This raises the question of whether there is a nontrivial class of network topologies for which achievability is always equivalent to routability, for any combination of source signals and positive channel capacities. This chapter considers possibly cyclic, directed, errorless networks with n source-sink pairs and mutually independent source signals. The concept of downward dominance is introduced and it is shown that, if the network topology is downward dominated, then the achievability of a given combination of source signals and channel capacities implies the existence of a feasible multicommodity flow.Comment: The final publication is available at link.springer.com http://link.springer.com/chapter/10.1007/978-3-319-02150-8_

Observations of the post shock break-out emission of SN 2011dh with XMM-Newton

After the occurrence of the type cIIb SN 2011dh in the nearby spiral galaxy M 51 numerous observations were performed with different telescopes in various bands ranging from radio to gamma-rays. We analysed the XMM-Newton and Swift observations taken 3 to 30 days after the SN explosion to study the X-ray spectrum of SN 2011dh. We extracted spectra from the XMM-Newton observations, which took place ~7 and 11 days after the SN. In addition, we created integrated Swift/XRT spectra of 3 to 10 days and 11 to 30 days. The spectra are well fitted with a power-law spectrum absorbed with Galactic foreground absorption. In addition, we find a harder spectral component in the first XMM-Newton spectrum taken at t ~ 7 d. This component is also detected in the first Swift spectrum of t = 3 - 10 d. While the persistent power-law component can be explained as inverse Compton emission from radio synchrotron emitting electrons, the harder component is most likely bremsstrahlung emission from the shocked stellar wind. Therefore, the harder X-ray emission that fades away after t ~ 10 d can be interpreted as emission from the shocked circumstellar wind of SN 2011dh.Comment: Accepted for publication as a Research Note in Astronomy and Astrophysic

RADNO PAMĆENJE I IZVRŠNE FUNKCIJE KOD OSOBA OBOLJELIH OD RATNOG POSTTRAUMATSKOG STRESNOG POREMEĆAJA

Posttraumatski stresni poremećaj (PTSP) povezan je s promjenama u kognitivnim funkcijama, teškoćama s pažnjom, pamćenjem i izvršnim sposobnostima. Cilj provedenog istraživanja bio je ispitati postojanje razlika u procesima radnog pamćenja i izvršnih sposobnosti kod oboljelih od PTSP-a u odnosu na zdrave ispitanike. U istraživanju je sudjelovalo 196 hrvatskih vojnih veterana (dvije kliničke skupine – s komorbiditetom i bez komorbiditeta) i 125 hrvatskih vojnika i civilnih pilota (komparabilna, usporedna skupina). Dijagnoza PTSP-a i PTSP-a s komorbiditetom (anksiozni, depresivni i somatoformni poremećaj) postavljena je pomoću Strukturiranog anamnestičkog upitnika za pred-traumatska, traumatska (borbena) i posttraumatska iskustva (SCID) i Međunarodnog neuro-psihijatrijskog intervjua (M.I.N.I:), te Kliničke ljestvice za posttraumatski stresni poremećaj (CAPS). U istraživanju su korištene i sljedeće ljestvice: Ljestvica pozitivnih i negativnih psihotičnih simptoma (PANSS), Hamiltonova ljestvica za depresiju (HAMD) . Mjerenje kognitivnih sposobnosti provodilo se Wechslerovom ljestvicom inteligencije za odrasle, treće revidirano izdanje (WAIS-III-R). Rezultati provedenog istraživanja potvrdili su postojanje značajnih razlika između oboljelih od PTSP-a i PTSP-a s komorbidnim dijagnozama (depresivni poremećaj, anksiozni poremećaj, somatoformni poremećaj) u odnosu na zdravu populaciju u sposobnostima radnog pamćenja i izvršnih funkcija pri čemu oboljeli od PTSP-a pokazuju snižene rezultate u ljestvicama izvršnih sposobnosti i radnog pamćenja. Nisu potvrđene razlike između PTSP-a kao jedinog poremećaja i PTSP-a s komorbidnim dijagnozama (depresivni i anksiozni poremećaj i somatoformni poremećaji) što ukazuje kako depresivni i anksiozni simptomi nisu djelovali na promjene u rezultatima kognitivnih sposobnosti. Zaključno, istraživanje potvrđuje da osobe koje su proživjele traumatska iskustva nakon kojih se razvio PTSP i/ili PTSP s komorbidnim dijagnozama imaju sniženo kognitivno funkcioniranje u području radnog pamćenja i izvršnih funkcija. Spoznaje iz provedenog istraživanja su doprinos boljem razumijevanju i utvrđivanju promjena kognitivnih sposobnosti koje se javljaju nakon traumatskog stresa

Formation of superdense hadronic matter in high energy heavy-ion collisions

We present the detail of a newly developed relativistic transport model (ART 1.0) for high energy heavy-ion collisions. Using this model, we first study the general collision dynamics between heavy ions at the AGS energies. We then show that in central collisions there exists a large volume of sufficiently long-lived superdense hadronic matter whose local baryon and energy densities exceed the critical densities for the hadronic matter to quark-gluon plasma transition. The size and lifetime of this matter are found to depend strongly on the equation of state. We also investigate the degree and time scale of thermalization as well as the radial flow during the expansion of the superdense hadronic matter. The flow velocity profile and the temperature of the hadronic matter at freeze-out are extracted. The transverse momentum and rapidity distributions of protons, pions and kaons calculated with and without the mean field are compared with each other and also with the preliminary data from the E866/E802 collaboration to search for experimental observables that are sensitive to the equation of state. It is found that these inclusive, single particle observables depend weakly on the equation of state. The difference between results obtained with and without the nuclear mean field is only about 20\%. The baryon transverse collective flow in the reaction plane is also analyzed. It is shown that both the flow parameter and the strength of the ``bounce-off'' effect are very sensitive to the equation of state. In particular, a soft equation of state with a compressibility of 200 MeV results in an increase of the flow parameter by a factor of 2.5 compared to the cascade case without the mean field. This large effect makes it possible to distinguish the predictions from different theoretical models and to detect the signaturesComment: 55 pages, latex, + 39 figures available upon reques

Bulks of Al-B-C obtained by reactively spark plasma sintering and impact properties by Split Hopkinson Pressure Bar

Mixtures of B4C, α-AlB12 and B powders were reactively spark plasma sintered at 1800 °C. Crystalline and amorphous boron powders were used. Samples were tested for their impact behavior by the Split Hopkinson Pressure Bar method. When the ratio R = B4C/α-AlB12 ≥ 1.3 for a constant B-amount, the major phase in the samples was the orthorhombic AlB24C4, and when R < 1 the amount of AlB24C4 significantly decreased. Predictions that AlB24C4 has the best mechanical impact properties since it is the most compact and close to the ideal cubic packing among the Al-B-C phases containing B12-type icosahedra were partially confirmed. Namely, the highest values of the Vickers hardness (32.4 GPa), dynamic strength (1323 MPa), strain and toughness were determined for the samples with R = 1.3, i.e., for the samples with a high amount of AlB24C4. However, the existence of a maximum, detectable especially in the dynamic strength vs. R, indicated the additional influence of the phases and the composite’s microstructure in the samples. The type of boron does not influence the dependencies of the indicated mechanical parameters with R, but the curves are shifted to slightly higher values for the samples in which amorphous boron was used

A novel electrode with multifunction and regeneration for highly efficient and stable symmetrical solid oxide cell

Authors acknowledge financial support from National Key Research & Development Project (2016YFE0126900), National Natural Science Foundation of China (51672095, U1910209), and China Scholarship Council (201806160178). The work is also partially supported by State Key Laboratory of Materials Processing and Die & Mould Technology, Huazhong University of Science and Technology (P2019-004).Symmetrical solid oxide cells (SSOCs) have been extensively recognized due to their simple cell configuration, low cost and reliability. High performance electrode is the key determinant of SSOCs. Herein, a multifunctional perovskite oxide La0.6Ca0.4Fe0.8Ni0.2O3-δ (LCaFN) is investigated as electrode for SSOCs. The results confirm that LCaFN shows excellent oxygen reduction reaction (ORR), oxygen evolution reaction (OER), carbon dioxide reduction reaction (CO2-RR) and hydrogen oxidation reaction (HOR) catalytic activity. In SOFC mode, the SSOCs with LCaFN achieve good electrochemical performance with maximum power density of 300 mW cm−2 at 800 °C. For pure CO2 electrolysis in SOEC mode, polarization resistance of 0.055 Ω cm2 and current density of 1.5 A cm−2 are achieved at 2.0 V at 800 °C. Besides, the cell shows excellent stability both in SOFC mode and SOEC mode. Most importantly, SSOCs with symmetrical LCaFN electrodes show robust and regenerative performance under anodic or cathodic process during the switching gas, showing the great reliability of the SSOCs. The results show that this novel electrode offers a promising strategy for operation of SSOCs.PostprintPeer reviewe