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Comparative analysis of ceramic-carbonate nanocomposite fuel cells using composite GDC/NLC electrolyte with different perovskite structured cathode materials

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Frontiers of Chemical Science and Engineering 2018年第1期12卷 162-173页

作者： Muhammad I. Asghar Sakari Lepikko Janne Patakangas Janne Halme Peter D. Lund New Energy Technologies Group Department of Applied Physics Aalto University P.O. BOX 15100 FI-00076 Aalto Finland

A comparative analysis of perovskite structured cathode materials, La0.65Sr0.35Mn03 （LSM）, La0.8Sr0.2CoO3 （LSC）, La0.6Sr0.4FeO3 （LSF） and La0.6Sr0.4Co0.2Fe0.803 （LSCF）, was performed for a ceramic-carbonate nanocomposite fuel cell using composite electrolyte consisting of Gd0.1Ce0.9O1.95 （GDC） and a eutectic mixture of Na2CO3 and Li2CO3. The compatibility of these nanocomposite electrode powder materials was investigated under air, CO2 and air/CO2 atmospheres at 550 ℃. Microscopy measurements together with energy dispersive X-ray spectroscopy （EDS） elementary analysis revealed few spots with higher counts of manganese relative to lanthanum and strontium under pure CO2 atmosphere. Furthermore, electrochemical impedance （EIS） analysis showed that LSC had the lowest resistance to oxygen reduction reaction （ORR）（14.12 Ω·cm^2） followed by LSF （15.23 Ω·cm^2）, LSCF （19.38Ω·cm^2） and LSM （〉 300 Ω·cm^2）. In addition, low frequency EIS measurements （down to 50 gHz） revealed two additional semi-circles at frequencies around 1 Hz. These semicircles can yield additional information about electrochemical reactions in the device. Finally, a fuel cell was fabricated using GDC/NLC nanocomposite electrolyte and its composite with NiO and LSCF as anode and cathode, respectively. The cell produced an excellent power density of 1.06 W/cm^2 at 550 ℃ under fuel cell conditions.

关键词： electrode fuel cell low-temperature nano- composite perovskite

Simulating Raman spectra by combining first-principles and empirical potential approaches with application to defective MoS_(2)

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npj Computational Materials 2020年第1期6卷 1182-1188页

作者： Zhennan Kou Arsalan Hashemi Martti J.Puska Arkady V.Krasheninnikov Hannu-Pekka Komsa Department of Applied Physics Aalto UniversityP.O.Box 1110000076 AaltoFinland Helmholtz-Zentrum Dresden-Rossendorf Institute of Ion Beam Physics and Materials Research01328 DresdenGermany Microelectronics Research Unit University of Oulu90014 OuluFinland

Successful application of two-dimensional transition metal dichalcogenides in optoelectronic,catalytic,or sensing devices heavily relies on the materials’quality,that is,the thickness uniformity,presence of grain boundaries,and the types and concentrations of point *** spectroscopy is a powerful and nondestructive tool to probe these factors but the interpretation of the spectra,especially the separation of different contributions,is not *** to simulated spectra is beneficial,but for defective systems first-principles simulations are often computationally too expensive due to the large sizes of the systems ***,we present a combined first-principles and empirical potential method for simulating Raman spectra of defective materials and apply it to monolayer MoS_(2) with random distributions of Mo and S *** study to what extent the types of vacancies can be distinguished and provide insight into the origin of different evolutions of Raman spectra upon increasing defect *** apply to our simulated spectra the phonon confinement model used in previous experiments to assess defect concentrations,and show that the simplest form of the model is insufficient to fully capture peak shapes,but a good match is obtained when the type of phonon confinement and the full phonon dispersion relation are accounted for.

关键词： spectra principles phonon

Effect of high negative incidence on the performance of a centrifugal compressor stage with conventional vaned diffusers

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Journal of Thermal Science 2011年第2期20卷 97-105页

作者： Ahti Jaatinen Aki Grnman Teemu Turunen-Saaresti Jari Backman Lappeenranta University of Technology

Three vaned diffusers, designed to have high negative incidence (-8°) at the design operating point, are studied experimentally. The overall performance (efficiency and pressure ratio) are measured at three rotational speeds, and flow angles before and after the diffuser are measured at the design rotational speed and with three mass flow rates. The results are compared to corresponding results of the original vaneless diffuser design. Attention is paid to the performance at lower mass flows than the design mass flow. The results show that it is possible to improve the performance at mass flows lower than the design mass flow with a vaned diffuser designed with high negative incidence. However, with the vaned diffusers, the compressor still stalls at higher mass flow rates than with the vaneless one. The flow angle distributions after the diffuser are more uniform with the vaned diffusers.

关键词： centrifugal compressor vaned diffuser efficiency performance flow field

Climate-driven synchrony in seed production of masting deciduous and conifer tree species

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Journal of Plant Ecology 2018年第2期11卷 180-188页

作者： Juan Gallego Zamorano Tatu Hokkanen Aleksi Lehikoinen The Helsinki Lab of Ornithology Finnish Museum of Natural HistoryHelsinki UniversityPO Box 1700014 HelsinkiFinland Natural Resources Institute finland PO Box 1801301 VantaaFinland

Aims Understanding fluctuations in plant reproductive investment can constitute a key challenge in ecology,conservation and *** events of trees(*** intermittent and synchronous production of abundant seeding material)is an extreme example of such *** objective was to establish the degree of spa-tial and temporal synchrony in common four masting tree species in boreal finland and account for potential causal drivers of these *** We investigated the spatial intraspecific and temporal interspe-cific fluctuations in annual seed production of four tree species in finland,silver birch Betula pendula Roth,downy birch Betula pubescens Ehrh.,Norway spruce Picea abies(L.)*** row-anberry Sorbus aucuparia *** also tested to see whether varia-tions in seed production were linked to annual weather *** abundance data were derived from tens of stands per spe-cies across large spatial scales within finland during 1979 to 2014(for rowanberries only 1986 to 2014).Important Findings All species showed spatial synchrony in seed production at scales up to 1000 *** estimates of seed production were strongly correlated between *** and summer temperatures explained most variation in crop sizes of tree species with 0-to 2-year time lags,whereas rainfall had relatively little *** weather during flowering(May temperature)in the flower-ing year(Year t)and 2 years before(t−2)were correlated with seed ***,high May temperatures during the previous year(t−1)adversely affected seed *** tempera-tures in Year t−1 was positively correlated with seed production,likely because this parameter enhances the development of flower primordials,but the effect was negative with a time lag of 2 *** negative feedback in temperature coefficients is also likely due to patterns of resource allocation,as abundant flowering and seed production in these species is thought to reduce the sub

关键词： climate change forest masting spatio-temporal synchrony

Detection of Anthropogenic CO_(2) Emission Signatures with TanSat CO_(2) and with Copernicus Sentinel-5 Precursor(S5P)NO_(2) Measurements:First Results

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Advances in Atmospheric Sciences 2023年第1期40卷 1-5页

作者： Dongxu YANG Janne HAKKARAINEN Yi LIU Iolanda IALONGO Zhaonan CAI Johanna TAMMINEN Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029China Finnish Meteorological Institute Helsinki FI-00560Finland

China’s first carbon dioxide(CO_(2))measurement satellite mission,TanSat,was launched in December *** paper introduces the first attempt to detect anthropogenic CO_(2) emission signatures using CO_(2) observations from TanSat and NO_(2) measurements from the TROPOspheric Monitoring Instrument(TROPOMI)onboard the Copernicus Sentinel-5 Precursor(S5P)*** focus our analysis on two selected cases in Tangshan,China and Tokyo,*** found that the TanSat XCO_(2) measurements have the capability to capture the anthropogenic variations in the plume and have spatial patterns similar to that of the TROPOMI NO_(2) *** linear fit between TanSat XCO_(2) and TROPOMI NO_(2) indicates the CO_(2)-to-NO_(2) ratio of 0.8×10^(-16) ppm(molec cm^(-2))^(-1) in Tangshan and 2.3×10^(-16) ppm(molec cm^(-2))^(-1) in *** results align with the CO_(2)-to-NOx emission ratios obtained from the EDGAR v6 emission inventory.

关键词： TanSat CO_(2) Remote sensing city carbon emission climate change

How to disentangle microbially functional complexity: an insight from the network analysis of C, N, P and S cycling genes

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Science Bulletin 2019年第16期64卷 1129-1131页

作者： Bang-Xiao Zheng Yi Zhao Qing-Fang Bi Guo-Wei Zhou Hong-Jie Wang Xiu-Li Hao Kai Ding Key Laboratory of Urban Environment and Health Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China Faculty of Biological and Environmental Sciences Ecosystems and Environment Research ProgrammeUniversity of HelsinkiNiemenkatu 73FI-15140 LahtiFinland Section for Microbial Ecology and Biotechnology Department of Plant and Environmental SciencesUniversity of CopenhagenThorvaldsenvej 40DK-1871 Frederiksberg CDenmark Key Laboratory of Subtropical Soil Science and Plant Nutrition of Zhejiang Province College of Environmental&Resource SciencesZhejiang UniversityHangzhou 310058China Department of Microbiology and Ecosystem Science Research Network'Chemistry Meets Microbiology’University of ViennaVienna A-1090Austria State Key Lab of Urban and Regional Ecology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China Microbial Ecophysiology Group Faculty of Biology/ChemistryUniversity of BremenD-28359 BremenGermany Institute for Environmental Genomics University of OklahomaNormanOK 73019USA State Key Laboratory of Agricultural Microbiology Huazhong Agricultural UniversityWuhan 430070China Key Laboratory of Arable Land Conservation(Middle and Lower Reaches of Yangtze River) Ministry of AgricultureCollege of Resources and EnvironmentHuazhong Agricultural UniversityWuhan 430070China

A complete ecosystem is also a complex network in which multifarious species interact with each other to achieve system-level functions, such as nutrient biogeochemistry (1)Microbial community is commonly considered as the primary driving force of ecosystem nutrient mobilization and metabolism, especially carbon (C), nitrogen (N), phosphorus (P), sulfur (S) and methane coupling process (2)The rise of metagenomics and high-throughput array (e.g. PhyloChip, GeoChip, etc.

关键词： net P and S cycling genes an insight from the network analysis of C How to disentangle microbially functional complexity

Nanoparticles-based phototherapy systems for cancer treatment: Current status and clinical potential

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Bioactive Materials 2023年第5期23卷 471-507页

作者： Jiachen Li Shiqi Wang Flavia Fontana Christos Tapeinos Mohammad-Ali Shahbazi Huijie Han Helder A.Santos Department of Biomedical Engineering W.J.Kolff Institute for Biomedical Engineering and Materials ScienceUniversity Medical Center GroningenUniversity of GroningenAnt.Deusinglaan 1Groningen9713 AVthe Netherlands W.J.Kolff Institute for Biomedical Engineering and Materials Science University Medical Center GroningenUniversity of GroningenUniversity of GroningenAntonius Deusinglaan 19713 AVGroningenthe Netherlands Drug Research Program Division of Pharmaceutical Chemistry and Technology Faculty of PharmacyUniversity of HelsinkiHelsinkiFI-00014Finland

Remarkable progress in phototherapy has been made in recent decades,due to its non-invasiveness and instant therapeutic *** addition,with the rapid development of nanoscience and nanotechnology,phototherapy systems based on nanoparticles or nanocomposites also evolved as an emerging hotspot in nanomedicine research,especially in *** this review,first we briefly introduce the history of phototherapy,and the mechanisms of phototherapy in cancer ***,we summarize the representative development over the past three to five years in nanoparticle-based phototherapy and highlight the design of the innovative nanoparticles ***,we discuss the feasibility and the potential of the nanoparticle-based phototherapy systems in clinical anticancer therapeutic applications,aiming to predict future research directions in this *** review is a tutorial work,aiming at providing useful insights to researchers in the field of nanotechnology,nanoscience and cancer.

关键词： Phototherapy Cancer Nanoparticles Therapeutic effect Clinical potential

Ultrafast transient sub-bandgap absorption of monolayer MoS2

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Light(Science & Applications) 2021年第2期10卷 234-242页

作者： Susobhan Das Yadong Wang Yunyun Dai Shisheng Li Zhipei Sun Department of Electronics and Nanoengineering Aalto University02150 EspooFinland International Center for Young Scientists(ICYS) National Institute for Materials Science(NIMS)TsukubaJapan QTF Centre of Excellence Department of Applied PhysicsAalto UniversityEspooFinland

The light-matter interaction in materials is of remarkable interest for various photonic and optoelectronic applications,which is intrinsically determined by the bandgap of the materials *** extend the applications beyond the bandgap limit,it is of great significance to study the light-matter interaction below the material ***,we report the ultrafast transient absorption of monolayer molybdenum disulfide in its sub-bandgap region from-0.86 pm to 1.4 *** though this spectral range is below the bandgap,we observe a significant absorbance enhancement up to-4.2%in the monolayer molybdenum disulfide(comparable to its absorption within the bandgap region)due to pump-induced absorption by the excited carrier *** different rise times of the transient absorption at different wavelengths indicate the various contributions of the different carrier states(i.e.,real carrier states in the short-wavelength region of~1μm).Our results elucidate the fundamental understanding regarding the optical properties,excited carrier states,and carrier dynamics in the technologically important near-infrared region,which potentially leads to various photonic and optoelectronic applications(e.g„excited-state-based photodetectors and modulators)of two-dimensional materials and their heterostructures beyond their intrinsic bandgap limitations.

关键词： absorption transient monolayer

Two decades of fire activity over the PEEX domain:a look from space,with contribution from models and ground-based measurements

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Big Earth Data 2024年第2期8卷 350-396页

作者： Larisa Sogacheva Timo H.Virtanen Anu-Maija Sundström Pekka Kolmonen Mikhail Sofiev Hanna K.Lappalainen Antti Arola Finnish Meteorological Institute Climate Research ProgrammeHelsinkiFinland Finnish Meteorological Institute Space and Earth Observation CentreHelsinkiFinland Institute for Atmospheric and Earth System Research/Physics Faculty of ScienceUniversity of HelsinkiHelsinkiFinland

It has been suggested that forest fires will become more frequent/intense with changing climate,which would increase aerosol/gas emissions into the atmosphere.A better under-standing of the relations between meteorological conditions,fires,and fire emissions will help estimate the climate response via forest *** this study,we use ERA5 meteor-ological products,including temperature,precipitation,and soil moisture,to explain the frequency of forest fires and the amount of radiant energy released per time unit by burning vegetation(fire radiative power,FRP).We explore the relation-ships between satellite-retrieved fire products and aerosol properties(aerosol optical depth,AOD),carbon monoxide(CO),formaldehyde(HCHO),and nitrogen dioxide(NO_(2))con-centrations over the PEEX domain,which covers different vegetation zones(***/grasslands,forest,arctic tun-dra)of Pan-Eurasia and *** analyse the concentrations of black carbon and absorbing organic carbon using groundbased AErosol RObotic *** analysis covers the months of May to August from 2002 to *** show posi-tive temperature trends in the Northern zone(>65°N)in June and August(1.56°C and 0.64°C,respectively);all statistically significant trends for precipitation and soil moisture are *** can explain increased fire activity in Siberia over the recent years(2019-2022).Over the whole PEEX domain,FC and FRP trends remain insignificant or negative;a decrease in AOD may address those negative *** show that intrasummer variations exist for cropland/grassland fires,which occur most often in May and August,while Siberian forest fires occur more often in July and *** show that CO concentration has been gradually decreasing in the last two decades in May and *** trends are negative in May,June,and over summer for all regions,in July in Europe,China,the Southern zone(<55°N),and the PEEX *** trends are not significant in all ***_(2)trends are positive in May and

关键词： PEEX wild fires satellite trend enhancement ratios