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Single atom Cu-N-C catalysts for the electro-reduction of CO_(2) to CO assessed by rotating ring-disc electrode

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Journal of Energy Chemistry 2024年第1期88卷 169-182,I0004页

作者： S.Pérez-Rodríguez m.Gutiérrez-Roa C.Giménez-Rubio d.Ríos-Ruiz P.Arévalo-Cid m.V.martínez-Huerta A.Zitolo m.J.Lázaro d.Sebastián Instituto de Carboquímica(CSIC) Miguel Luesma Castán 450018 ZaragozaSpain Instituto de Catálisis y Petroleoquímica(CSIC) Marie Curie 228049 MadridSpain Synchrotron SOLEIL L’Orme des MerisiersDépartementale 12891190France

The electrochemical CO_(2) reduction reaction(CO_(2)RR) to controllable chemicals is considered as a promising pathway to store intermittent renewable energy. Herein, a set of catalysts based on copper-nitrogendoped carbon xerogel(Cu-N-C) are successfully developed varying the copper amount and the nature of the copper precursor, for the efficient CO_(2)RR. The electrocatalytic performance of Cu-N-C materials is assessed by a rotating ring-disc electrode(RRdE), technique still rarely explored for CO_(2)RR. For comparison, products are also characterized by online gas chromatography in a H-cell. The as-synthesized Cu-NC catalysts are found to be active and highly CO selective at low overpotentials(from -0.6 to -0.8 V ***) in 0.1 m KHCO_(3), while H_(2) from the competitive water reduction appears at larger overpotentials(-0.9 V vs. RHE). The optimum copper acetate-derived catalyst containing Cu-N_(4) moieties exhibits a CO_(2)-to-CO turnover frequency of 997 h^(-1) at -0.9 V vs. RHE with a H_(2)/CO ratio of 1.8. These results demonstrate that RRdE configuration can be used as a feasible approach for identifying electrolysis products from CO_(2)RR.

关键词： Cu-N-C Carbon xerogel Rotating ring disc electrode Carbon dioxide reduction reaction Carbon monoxide

Interfacial stress engineering toward enhancement of ferroelectricity in Al doped HfO_(2)thin films

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Chinese Physics B 2024年第9期33卷 637-643页

作者： S X Chen m m Chen Y Liu d W Cao G J Chen department of microelectronics Jiangsu UniversityZhenjiang 212013China department of Physics Jiangsu UniversityZhenjiang 212013China Guangdong–Hong Kong–macao Joint Laboratory for Intelligent micro-Nano Optoelectronic Technology Foshan UniversityFoshan 528225China

Ferroelectric HfO_(2)has attracted much attention owing to its superior ferroelectricity at an ultra-thin thickness and good compatibility with Si-based complementary metal-oxide-semiconductor(CmOS)***,the crystallization of polar orthorhombic phase(o-phase)HfO_(2)is less competitive,which greatly limits the ferroelectricity of the as-obtained ferroelectric HfO_(2)thin ***,the crystallization of o-phase HfO_(2)can be thermodynamically modulated via interfacial stress *** this paper,the growth of improved ferroelectric Al doped HfO_(2)(HfO_(2):Al)thin films on(111)-oriented Si substrate has been *** analysis has suggested that nonpolar monoclinic HfO_(2):Al grown on(111)-oriented Si substrate suffered from a strong compressive strain,which promoted the crystallization of(111)-oriented o-phase HfO_(2)in the as-grown HfO_(2):Al thin *** addition,the in-plane lattice of(111)-oriented Si substrate matches well with that of(111)-oriented o-phase HfO_(2),which further thermally stabilizes the o-phase HfO_(2).Accordingly,an improved ferroelectricity with a remnant polarization(2P_(r))of 26.7C/cm^(2) has been *** results shown in this work provide a simple way toward the preparation of improved ferroelectric HfO_(2)thin films.

关键词： improved ferroelectricity interfacial stress engineering compressive strain HfO_(2)

Greatly enhanced corrosion/wear resistances of epoxy coating for mg alloy through a synergistic effect between functionalized graphene and insulated blocking layer

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Journal of magnesium and Alloys 2024年第1期12卷 332-344页

作者： Z.Y.Xue X.J.Li J.H.Chu m.m.Li d.N.Zou L.B.Tong School of metallurgical Engineering Xi’an University of Architecture and TechnologyXi’an 710055China State Key Laboratory of Advanced design and manufacturing for Vehicle Body Hunan UniversityChangsha 410082China

The poor corrosion and wear resistances of mg alloys seriously limit their potential applications in various *** conventional epoxy coating easily forms many intrinsic defects during the solidification process,which cannot provide sufficient *** the current study,we design a double-layer epoxy composite coating on mg alloy with enhanced anti-corrosion/wear properties,via the spin-assisted assembly *** outer layer is functionalized graphene(FG)in waterborne epoxy resin(WEP)and the inner layer is Ce-based conversion(Ce)*** FG sheets can be homogeneously dispersed within the epoxy matrix to fill the intrinsic defects and improve the barrier *** Ce film connects the outer layer with the substrate,showing the transition *** corrosion rate of Ce/WEP/FG composite coating is 2131 times lower than that of bare mg alloy,and the wear rate is decreased by~90%.The improved corrosion resistance is attributed to the labyrinth effect(hindering the penetration of corrosive medium)and the obstruction of galvanic coupling *** synergistic effect derived from the FG sheet and blocking layer exhibits great potential in realizing the improvement of multi-functional integration,which will open up a new avenue for the development of novel composite protection coatings of mg alloys.

关键词： mg alloy Functionalized graphene Epoxy coating Corrosion/wear resistance Blocking layer

Ion heat transport in electron cyclotron resonance heated L-mode plasma on the T-10 tokamak

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Plasma Science and Technology 2024年第4期26卷 52-60页

作者： V.A.KRUPIN m.R.NURGALIEV A.R.NEmETS I.A.ZEmTSOV S.d.SUNTSOV T.B.mYALTON d.S.SERGEEV N.A.SOLOVEV d.V.SARYCHEV d.V.RYJAKOV S.N.TUGARINOV N.N.NAUmENKO National Research Centre“Kurchatov Institute” Moscow 123182Russia Bauman moscow State Technical University Moscow 105005Russia Institution“Project Center ITER” Moscow 123098Russia JSC“SOLAR” Minsk 220034Belarus

Anomalous ion heat transport is analyzed in the T-10 tokamak plasma heated with electron cyclotron resonance heating(ECRH) in second-harmonic extra-ordinary mode. Predictive modeling with empirical scaling for Ohmical heat conductivity shows that in ECRH plasmas the calculated ion temperature could be overestimated, so an increase of anomalous ion heat transport is required. To study this effect two scans are presented: over the EC resonance position and over the ECRH power. The EC resonance position varies from the high-field side to the low-field side by variation of the toroidal magnetic field. The scan over the heating power is presented with on-axis and mixed ECRH regimes. discharges with high anomalous ion heat transport are obtained in all considered regimes. In these discharges the power balance ion heat conductivity exceeds the neoclassical level by up to 10 times. The high ion heat transport regimes are distinguished by three parameters: the ratio Te/Ti, the normalized electron density gradient R/■, and the ion–ion collisionality νii~*. The combination of high Te/Ti, high νii~*, and R/■=6-10 results in values of normalized anomalous ion heat fluxes up to 10 times higher than in the low transport scenario.

关键词： tokamak L-mode electron cyclotron resonance heating ion heat transport

Understanding the catalysis of chromium trioxide added magnesium hydride for hydrogen storage and Li ion battery applications

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Journal of magnesium and Alloys 2024年第3期12卷 1117-1130页

作者： d.Pukazhselvan IhsanÇaha Catarina de Lemos Sergey m.mikhalev Francis Leonard deepak duncan Paul Fagg department of mechanical Engineering TEMA-Centre for Mechanical Technology and AutomationUniversity of AveiroAveiro 3810-193Portugal LASI-Intelligent Systems Associate Laboratory Guimarães 4800-058Portugal Nanostructured materials Group International Iberian Nanotechnology Laboratory(INL)Avenida Mestre Jose VeigaBraga 4715-330Portugal

This study explores how the chemical interaction between magnesium hydride(mgH_(2))and the additive CrO_(3) influences the hydrogen/lithium storage characteristics of mgH_(2).We have observed that a 5 wt.%CrO_(3) additive reduces the dehydrogenation activation energy of mgH_(2) by 68 kJ/mol and lowers the required dehydrogenation temperature by 80℃.CrO_(3) added mgH_(2) was also tested as an anode in an Li ion battery,and it is possible to deliver over 90%of the total theoretical capacity(2038 mAh/g).Evidence for improved reversibility in the battery reaction is found only after the incorporation of additives with mgH_(2).In depth characterization study by X-ray diffraction(XRd)technique provides convincing evidence that the CrO_(3) additive interacts with mgH_(2) and produces Cr/mgO *** free energy analyses confirm the thermodynamic feasibility of conversion from mgH_(2)/CrO_(3) to mgO/Cr,which is well supported by the identification of Cr(0)in the powder by X ray photoelectron spectroscopy(XPS)*** high resolution transmission electron microscopy(HRTEm)and energy dispersive spectroscopy(EdS)we found evidence for the presence of 5 nm size Cr nanocrystals on the surface of mgO rock salt *** is also convincing ground to consider that mgO rock salt accommodates Cr in the *** observations support the argument that creation of active metal–metal dissolved rock salt oxide interface may be vital for improving the reactivity of mgH_(2),both for the improved storage of hydrogen and lithium.

关键词： Hydrogen storage Rechargeable batteries Binary hydrides metal oxides Catalytic mechanism.

Structural effects induced by dialysis-based purification of carbon nanomaterials

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Nano materials Science 2024年第4期6卷 475-483页

作者： A.d.Veloso A.m.Ferraria A.m.Botelho do Rego A.S.Viana A.J.S.Fernandes A.J.Fielding R.A.Videira m.C.Oliveira CQ-VR and Chemistry department University of Trás-os-Montes e Alto Douro BSIRG iBB-Institute for Bioengineering and BiosciencesDepartment of Chemical Engineeringand Associate Laboratory i4HB-Institute for Health and BioeconomyInstituto Superior TécnicoUniversidade de Lisboa Centro de Química Estrutural Institute of Molecular SciencesDepartamento de Química e BioquímicaFaculdade de CiênciasUniversidade de Lisboa I3N and Physics department University of AveiroCampus de Santiago Faculty of Science Pharmacy and Biomolecular SchoolLiverpool John Moores University REQUImTE/LAQV Laborat orio de FarmacognosiaDepartamento de QuímicaFaculdade de Farm aciaUniversidade do Porto

dialysis plays a crucial role in the purification of nanomaterials but its impact on the structural properties of carbon nanomaterials was never ***,a carbon-based nanomaterial generated electrochemically in potassium phosphate buffer,was characterized before and after dialysis against pure *** is shown that dialysis affects the size of the carbon domains,structural organization,surface functionalization,oxidation degree of carbon,and grade of ***,dialysis drives the nanomaterial organization from discrete roundish carbon domains,with sizes ranging from 70 to 160 nm,towards linear stacking structures of small nanoparticles （m）.In parallel,alcohol and ether （epoxide） surface groups evolve into more oxidized carbon groups （e.g.,ketone and ester groups）.Investigation of the as-prepared nanomaterial by electron paramagnetic resonance （EPR） revealed a resonance signal consistent with carbon-oxygen centred ***,this study brings to light the selective affinity of the carbon nanomaterial under study to capture Na+ions,a property greatly enhanced by the dialysis process,and its high ability to trap oxygen,particularly before *** findings open new perspectives for the application of carbon-based nanomaterials and raise awareness of the importance of structural changes that can occur during the purification of carbon-based nanomaterials.

关键词： Nanocarbon Surface functionalization NmR XPS Hydrophilic carbon Paramagnetic

Effects of low molecular weight polysaccharide from Sargassum thunbergii against palmitic acid-induced intracellular lipid accumulation in 3T3-L1 adipocyte and HepG2 cells

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Food Science and Human Wellness 2024年第4期13卷 2244-2252页

作者： Hyo-Geun Lee d.P.Nagahawatta m.J.m.S.Kurera Kyung-mo Song Yun-Sang Choi You-Jin Jeon min-Cheol Kang department of marine Life Sciences Jeju National UniversityJeju 63243Republic of Korea department of Biotechnology Faculty of Agriculture and Plantation ManagementWayamba University of Sri LankaMakanduraGonawila(NWP)60170Sri Lanka Research Group of Food Processing Korea Food Research Institute245Wanju 55365Republic of Korea

Low molecular weight polysaccharides can be isolated from Sargassum thunbergii(LmPST)and in vitro experiments were conducted to evaluate the inhibitory effects on *** natures of LmPST were attained from *** and appraised their LmPST on palmitic acid(PA)induced lipid accretion in Hep G2,and 3T3-L1 *** treatment lessened lipid deposition and intracellular free fatty acid and triglyceride intensities in PA-treated above mentioned *** mechanistic study publicized that LmPST2 significantly suppressed adipogenesis and stimulated the PA-treated 3T3-L1 cells occupied in the lipolysis ***,in PA-treated Hep G2 cells,the free fatty acid oxidation was significantly increased by *** these constructive properties of LmPST2 from ***,is a potential candidate for diminishing the intracellular lipids,and for a therapeutic agent in those conditions.

关键词： Sargassum thunbergii Low molecular weight polysaccharide Lipid accumulation Obesity Liver steatosis

Forecasting of tropical cyclones ASANI(2022)and mOCHA(2023)over the Bay of Bengal-real time challenges to forecasters

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Tropical Cyclone Research and Review 2024年第2期13卷 88-112页

作者： S.d.Kotal T.Arulalan m.mohapatra India meteorological department Ministry of Earth ScienceGovernment of IndiaNew DelhiIndia

This study examines the track and intensity forecasts of two typical Bay of Bengal tropical cyclones(TC)ASANI and *** analysis of various Numerical Weather Prediction(NWP)model forecasts[ECmWF(European Centre for medium range Weather Forecast),NCEP(National Centers for Environmental Prediction),NCUm(National Centre for medium Range Weather Forecast-Uniﬁed model),Imd(India meteorological department),HWRF(Hurricane Weather Research and Forecasting)],mmE(multi-model Ensemble),SCIP(Statistical Cyclone Intensity Prediction)model,and OFCL(Ofﬁcial)forecasts shows that intensity forecasts of ASANI and track forecasts of mOCHA were reasonably good,but there were large errors and wide variation in track forecasts of ASANI and in intensity forecasts of *** all model forecasts,the track forecast errors of Imd model and mmE were least in general for ASANI and mOCHA ***,the landfall point forecast errors of Imd were least for ASANI,and the mmE and OFCL forecast errors were least for *** model is found to be consistently better for landfall time forecast for ASANI,and the errors of ECmWF,Imd and HWRF were least and of same order for *** intensity forecast errors of OFCL and SCIP were least for ASANI,and the forecast errors of HWRF,Imd,NCEP,SCIP and OFCL were comparable and least for mOCHA up to 48 h forecast and HWRF errors were least thereafter in *** ECmWF model forecast errors for intensity were found to be highest for both the *** results also show that although there is signiﬁcant improvement of track forecasts and limited or no improvement of intensity forecast in previous decades but challenges still persists in real time forecasting of both track and intensity due to wide variation and inconsistency of model forecasts for different TC cases.

关键词： Tropical cyclone Track forecast Intensity forecast NWP model Bay of Bengal North Indian Ocean

Ferroelectricity Induced by Oxygen Vacancies in Rhombohedral ZrO_(2) Thin Films

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Energy & Environmental materials 2024年第1期7卷 229-237页

作者： Veniero Lenzi José P.B.Silva Břetislav Šmíd Vladimir matoín Cosmin m.Istrate Corneliu Ghica Judith L.macmanus-driscoll Luís marques Physics Center of minho and Porto Universities(CF-Um-UP) University of MinhoCampus de Gualtar 4710-057Braga Portugal Laboratory of Physics for materials and Emergent Technologies LapMETUniversity of Minho4710-057Braga Portugal department of Surface and Plasma Science Faculty of Mathematics and PhysicsCharles UniversityV Holešovičkách 218000Prague 8 Czech Republic National Institute of materials Physics 105 bis Atomistilor 077125Magurele Romania department of materials Science and metallurgy 27 Charles Babbage Rd.Cambridge CB3 OFSUK

Rhombohedral phase Hf_(x)Zr_(1.x)O_(2)(HZO,x from 0 to 1)films are promising for achieving robust ferroelectric polarization without the need for an initial wake-up pre-cycling,as is normally the case for the more commonly studied orthorhombic ***,a large spontaneous polarization observed in rhombohedral films is not fully understood,and there are also large discrepancies between experimental and theoretical *** this work,in rhombohedral ZrO_(2)thin films,we show that oxygen vacancies are not only a key factor for stabilizing the phase,but they are also a source of ferroelectric polarization in the *** is shown experimentally through the investigation of the structural properties,chemical composition and the ferroelectric properties of the films before and after an annealing at moderate temperature(400℃)in an oxygen environment to reduce the V_(o)concentration *** experimental work is supported by density functional theory(dFT)calculations which show that the rhombohedral phase is the most stable one in highly oxygen defective ZrO_(2)*** dFT calculations also show that V_(o)contribute to the ferroelectric *** findings reveal the importance of V_(o)for stabilizing rhombohedral ZrO_(2)thin films with superior ferroelectric properties.

关键词： charged defects ferroelectric polarization rhombohedral phase stability zirconia