Fractions of various heavy metals in a sulfidic minespoil were investigated. Column leaching experimentwas also conducted to simulate 'acid mine drainage' (AMD) from the minespoil. The results show thatleachin...Fractions of various heavy metals in a sulfidic minespoil were investigated. Column leaching experimentwas also conducted to simulate 'acid mine drainage' (AMD) from the minespoil. The results show thatleaching of heavy metals from the minespoil was extremely significant during the initial water flushing.The amounts of heavy metals leached out dramatically reduced after leaching twice. It is worthwhile tonote that in this study, Zn, Mn, Fe, As and Ni in the first leachate exceeded the total amount of eachcorresponding water-extractable (1:5, soil:water) metal contained in the minespoil sample. This appears tosuggest that 1:5 water extraction did not allow accurate estimation of water-leachable concentrations of theabove heavy metals. This work has implications for the management of sulfidic minespoils. Acid drainageof great environmental concerns is likely to occur only during heavy rainfall events after substantial solubleand readily exchangeable acid and metals are accumulated in the minespoils. The slow-reacting fractionsother than water-soluble and readily exchangeable fractions may pose little environmental hazards. This isparticularly true for Pb, As and Ni.展开更多
Low temperature fuel cells are an attractive technology for transportation and residential applica-tions due to their quick start up and shut down capabilities. This review analyzed the current status of nanocatalysts...Low temperature fuel cells are an attractive technology for transportation and residential applica-tions due to their quick start up and shut down capabilities. This review analyzed the current status of nanocatalysts for proton exchange membrane fuel cells and alkaline membrane fuel cells. The preparation process influences the performance of the nanocatalyst. Several synthesis methods are covered for noble and non-noble metal catalysts on various catalyst supports including carbon nanotubes, carbon nanofibers, nanowires, and graphenes. Ex situ and in situ characterization methods like scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and fuel cell testing of the nanocatalysts on various supports for both proton exchange and alkaline membrane fuel cells are discussed. The accelerated durability estimate of the nanocat-alysts, predicted by measuring changes in the electrochemically active surface area using a voltage cycling method, is considered one of the most reliable and valuable method for establishing durabil-ity.展开更多
The evolution of the microstructure and texture in copper has been studied during repetitive extrusionupsetting（REU） to a total von Mises strain of 4.7 and during subsequent annealing at different temperatures. It i...The evolution of the microstructure and texture in copper has been studied during repetitive extrusionupsetting（REU） to a total von Mises strain of 4.7 and during subsequent annealing at different temperatures. It is found that the texture is significantly altered by each deformation pass. A duplex 001 ＋ 111 fiber texture with an increased 111 component is observed after each extrusion pass,whereas the 110 fiber component dominates the texture after each upsetting pass. During REU, the microstructure is refined by deformation-induced boundaries. The average cell size after a total strain of 4.7 is measured to be ~0.3 μm. This refined microstructure is unstable at room temperature as is evident from the presence of a small number of recrystallized grains in the deformed matrix. Pronounced recrystallization took place during annealing at 200？C for 1 h with recrystallized grains developing predominantly in high misorientation regions. At 350？C the microstructure is fully recrystallized with an average grain size of only 2.3 μm and a very weak crystallographic texture. This REU-processed and subsequently annealed material is considered to be potentially suitable for using as a material for sputtering targets.展开更多
A localized space-time method of fundamental solutions(LSTMFS)is extended for solving three-dimensional transient diffusion problems in this paper.The interval segmentation in temporal direction is developed for the a...A localized space-time method of fundamental solutions(LSTMFS)is extended for solving three-dimensional transient diffusion problems in this paper.The interval segmentation in temporal direction is developed for the accurate simulation of long-time-dependent diffusion problems.In the LSTMFS,the whole space-time domain with nodes arranged i divided into a series of overlapping subdomains with a simple geometry.In each subdomain,the conventional method of fundamental solutions is utilized and the coefficients associated with the considered domain can be explicitly determined.By calculating a combined sparse matrix system,the value at any node inside the space-time domain can be obtained.Numerical experi-ments demonstrate that high accuracy and efficiency can be simultaneously achieved via the LSTMFS,even for the problems defined on a long-time and quite complex computational domain.展开更多
An incubation experiment was conducted to simulate the effect of flooding onwater deoxygenation in acid sulfate soil floodplain systems. The originally oxygenated 'floodwater'could be deoxygenated immediately ...An incubation experiment was conducted to simulate the effect of flooding onwater deoxygenation in acid sulfate soil floodplain systems. The originally oxygenated 'floodwater'could be deoxygenated immediately following 'flooding' and it is likelythat this was caused mainlyby decomposition of organic debris from the inundated plants. Deoxygenation eventually led to thedepletion of dissolved oxygen (DO) in the 'floodwater' and it is highly possible that this resultedin the transformations of ferric Fe to ferrous Fe, sulfate to hydrogen sulfide. and organic nitrogento ammonia (ammonification). The accumulation of these reduced substances allows the 'floodwater'to develop DO-consuming capacity (DOCC). When the 'floodwater' is mixed with the introducedoxygenated water, apart from the dilution effects, the reduced substances contained in the'floodwater' oxidize to further consume DO carried by the introduced water. However, it appears thatthe DO drop in the mixed water can only last for a few hours if no additional DO-depleted'floodwater' is added. Entry of atmospheric oxygen into the water can raise the DO level of themixed water arid lower water pH through the oxidation of the reduced substances.展开更多
series of data samples was collected with the Belle Ⅱ detector at the SuperKEKB collider from March 2019 to June 2022.We determine the integrated luminosities of these data samples using three distinct methodologies ...series of data samples was collected with the Belle Ⅱ detector at the SuperKEKB collider from March 2019 to June 2022.We determine the integrated luminosities of these data samples using three distinct methodologies involving Bhabha(e^(+)e^(-)→e^(+)e^(-)(ny),digamma(e^(+)e^(-)→γγ(nγ),and dimuon(e^(+)e^(-)→μ^(+)μ^(-)(nγ)events.The total integrated luminosity obtained with Bhabha,digamma,and dimuon events is(426.88±0.03±2.61)fb^(-1),(429.28±0.03±2.62)fb^(-1),and(423.99±0.04±3.83)fb^(-1),where the first uncertainties are statistical and the second are systematic.The resulting total integrated luminosity obtained from the combination of the three methods is(427.87±2.01)fb^(-1).展开更多
基金Project partly supported by an internal grant of Southern Cross University,Australia(Project No.305093).
文摘Fractions of various heavy metals in a sulfidic minespoil were investigated. Column leaching experimentwas also conducted to simulate 'acid mine drainage' (AMD) from the minespoil. The results show thatleaching of heavy metals from the minespoil was extremely significant during the initial water flushing.The amounts of heavy metals leached out dramatically reduced after leaching twice. It is worthwhile tonote that in this study, Zn, Mn, Fe, As and Ni in the first leachate exceeded the total amount of eachcorresponding water-extractable (1:5, soil:water) metal contained in the minespoil sample. This appears tosuggest that 1:5 water extraction did not allow accurate estimation of water-leachable concentrations of theabove heavy metals. This work has implications for the management of sulfidic minespoils. Acid drainageof great environmental concerns is likely to occur only during heavy rainfall events after substantial solubleand readily exchangeable acid and metals are accumulated in the minespoils. The slow-reacting fractionsother than water-soluble and readily exchangeable fractions may pose little environmental hazards. This isparticularly true for Pb, As and Ni.
基金financial support from the Arizona State University
文摘Low temperature fuel cells are an attractive technology for transportation and residential applica-tions due to their quick start up and shut down capabilities. This review analyzed the current status of nanocatalysts for proton exchange membrane fuel cells and alkaline membrane fuel cells. The preparation process influences the performance of the nanocatalyst. Several synthesis methods are covered for noble and non-noble metal catalysts on various catalyst supports including carbon nanotubes, carbon nanofibers, nanowires, and graphenes. Ex situ and in situ characterization methods like scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and fuel cell testing of the nanocatalysts on various supports for both proton exchange and alkaline membrane fuel cells are discussed. The accelerated durability estimate of the nanocat-alysts, predicted by measuring changes in the electrochemically active surface area using a voltage cycling method, is considered one of the most reliable and valuable method for establishing durabil-ity.
基金supported by the Chongqing Research Program of Basic Research and Frontier Technology (No. cstc2015jcyj BX0115)support of the “111” Project (B16007) by the Ministry of Education and the State Administration of Foreign Experts Affairs of Chinathe National Natural Science Foundation of China (Nos. 51471039, 51421001)
文摘The evolution of the microstructure and texture in copper has been studied during repetitive extrusionupsetting（REU） to a total von Mises strain of 4.7 and during subsequent annealing at different temperatures. It is found that the texture is significantly altered by each deformation pass. A duplex 001 ＋ 111 fiber texture with an increased 111 component is observed after each extrusion pass,whereas the 110 fiber component dominates the texture after each upsetting pass. During REU, the microstructure is refined by deformation-induced boundaries. The average cell size after a total strain of 4.7 is measured to be ~0.3 μm. This refined microstructure is unstable at room temperature as is evident from the presence of a small number of recrystallized grains in the deformed matrix. Pronounced recrystallization took place during annealing at 200？C for 1 h with recrystallized grains developing predominantly in high misorientation regions. At 350？C the microstructure is fully recrystallized with an average grain size of only 2.3 μm and a very weak crystallographic texture. This REU-processed and subsequently annealed material is considered to be potentially suitable for using as a material for sputtering targets.
基金the Fundamental Research Funds for the Central Universities(Grants B200203009 and B200202126)the Natural Science Foundation of Jiangsu Province(Grant BK20190073)+2 种基金the State Key Laboratory of Acoustics,Chinese Academy of Sciences(Grant SKLA202001)the State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures,Shijiazhuang Tiedao University(Grant KF2020-22)the China Postdoctoral Science Foundation(Grants 2017M611669 and 2018T110430).
文摘A localized space-time method of fundamental solutions(LSTMFS)is extended for solving three-dimensional transient diffusion problems in this paper.The interval segmentation in temporal direction is developed for the accurate simulation of long-time-dependent diffusion problems.In the LSTMFS,the whole space-time domain with nodes arranged i divided into a series of overlapping subdomains with a simple geometry.In each subdomain,the conventional method of fundamental solutions is utilized and the coefficients associated with the considered domain can be explicitly determined.By calculating a combined sparse matrix system,the value at any node inside the space-time domain can be obtained.Numerical experi-ments demonstrate that high accuracy and efficiency can be simultaneously achieved via the LSTMFS,even for the problems defined on a long-time and quite complex computational domain.
基金Project partly supported by Australian Research Council and NSW Agriculture.
文摘An incubation experiment was conducted to simulate the effect of flooding onwater deoxygenation in acid sulfate soil floodplain systems. The originally oxygenated 'floodwater'could be deoxygenated immediately following 'flooding' and it is likelythat this was caused mainlyby decomposition of organic debris from the inundated plants. Deoxygenation eventually led to thedepletion of dissolved oxygen (DO) in the 'floodwater' and it is highly possible that this resultedin the transformations of ferric Fe to ferrous Fe, sulfate to hydrogen sulfide. and organic nitrogento ammonia (ammonification). The accumulation of these reduced substances allows the 'floodwater'to develop DO-consuming capacity (DOCC). When the 'floodwater' is mixed with the introducedoxygenated water, apart from the dilution effects, the reduced substances contained in the'floodwater' oxidize to further consume DO carried by the introduced water. However, it appears thatthe DO drop in the mixed water can only last for a few hours if no additional DO-depleted'floodwater' is added. Entry of atmospheric oxygen into the water can raise the DO level of themixed water arid lower water pH through the oxidation of the reduced substances.
基金supported by Higher Education and Science Committee of the Republic of Armenia(23LCG-1C011)Australian Research Council and Research(DP200101792,DP210101900,DP210102831,DE220100462,LE210100098,LE230100085)+41 种基金Austrian Federal Ministry of Education,Science and Research,Austrian Science Fund(P 34529,J 4731,J 4625,M 3153)Horizon 2020 ERC Starting(947006)“InterLeptons”Natural Sciences and Engineering Research Council of Canada,Compute Canada and CANARIENational Key R&D Program of China(2022YFA1601903)National Natural Science Foundation of China(11575017,11761141009,11705209,11975076,12135005,12150004,12161141008,12175041)Natural Science Foundation Project of Shandong Province,China(ZR2022JQ02)the Czech Science Foundation(22-18469S)and Charles University Grant Agency(246122)European Research Council,Seventh Framework(PIEF-GA-2013-622527)Horizon 2020 ERC-Advanced(Grant Nos.267104 and 884719)Horizon 2020 ERC-Consolidator(819127)Horizon 2020 Marie Sklodowska-Curie Grant Agreement(700525)“NIOBE”and(101026516)Horizon 2020 Marie Sklodowska-Curie RISE project JENNIFER2 Grant Agreement(822070)(European grants)L'Institut National de Physique Nucléaire et de Physique des Particules(IN2P3)du CNRS and L'Agence Nationale de la Recherche(ANR)(ANR-21-CE31-0009)(France)BMBF,DFG,HGF,MPG,and AvH Foundation(Germany)Department of Atomic Energy under Project Identification(RTI 4002)Department of Science and Technology,and UPES SEED funding programs(UPES/R&D-SEED-INFRA/17052023/01,UPES/R&D-SOE/20062022/06)(India)Israel Science Foundation(2476/17)U.S.-Israel Binational Science Foundation(2016113)Israel Ministry of Science(3-16543)Istituto Nazionale di Fisica Nucleare and the Research Grants BELLE2Japan Society for the Promotion of Science,Grant-in-Aid for Scientific Research(16H03968,16H03993,16H06492,16K05323,17H01133,17H05405,18K03621,18H03710,18H05226,19H00682,20H05850,20H05858,22H00144,22K14056,22K21347,23H05433,26220706,26400255)the Ministry of Education,Culture,Sports,Science,and Technology(MEXT)of JapanNational Research Foundation(NRF)of Korea(2016R1D1A1B02012900,2018R1A2B3003643,2018R1A6A1A06024970,2019R1I1A3A01058933,2021R1A6A1A03043957,2021R1F1A1060423,2021R1F1A1064008,2022R1A2C1003993,RS-2022-00197659)Radiation Science Research Institute,Foreign Large-Size Research Facility Application Supporting project,the Global Science Experimental Data Hub Center of the Korea Institute of Science and Technology Information and KREONET/GLORIADUniversiti Malaya RU grant,Akademi Sains Malaysia,and Ministry of Education MalaysiaFrontiers of Science Program(FOINS-296,CB-221329,CB-236394,CB-254409,CB-180023)SEP-CINVESTAV Research(237)(Mexico)the Polish Ministry of Science and Higher Education and the National Science Centerthe Ministry of Science and Higher Education of the Russian Federation and the HSE University Basic Research Program,MoscowUniversity of Tabuk Research(S-0256-1438,S-0280-1439)(Saudi Arabia)Slovenian Research Agency and Research(J1-9124,P1-0135)Agencia Estatal de Investigacion,Spain(RYC2020-029875-I)Generalitat Valenciana,Spain(CIDEGENT/2018/020)The Knut and Alice Wallenberg Foundation(Sweden),(2021.0174,2021.0299)National Science and Technology Council,and Ministry of EducationThailand Center of Excellence in PhysicsTUBITAK ULAKBIM(Turkey)National Research Foundation of Ukraine,(2020.02/0257)Ministry of Education and Science of Ukrainethe U.S.National Science Foundation and Research(PHY-1913789,PHY-2111604)the U.S.Department of Energy and Research Awards(DE-AC06-76RLO1830,DE-SC0007983,DESC0009824,DE-SC0009973,DE-SC0010007,DE-SC0010073,DE-SC0010118,DE-SC0010504,DE-SC0011784,DE-SC0012704,DE-SC0019230,DESC0021274,DE-SC0021616,DE-SC0022350,DE-SC0023470)the Vietnam Academy of Science and Technology(VAST)(NVCC.05.12/22-23,DL0000.02/24-25)。
文摘series of data samples was collected with the Belle Ⅱ detector at the SuperKEKB collider from March 2019 to June 2022.We determine the integrated luminosities of these data samples using three distinct methodologies involving Bhabha(e^(+)e^(-)→e^(+)e^(-)(ny),digamma(e^(+)e^(-)→γγ(nγ),and dimuon(e^(+)e^(-)→μ^(+)μ^(-)(nγ)events.The total integrated luminosity obtained with Bhabha,digamma,and dimuon events is(426.88±0.03±2.61)fb^(-1),(429.28±0.03±2.62)fb^(-1),and(423.99±0.04±3.83)fb^(-1),where the first uncertainties are statistical and the second are systematic.The resulting total integrated luminosity obtained from the combination of the three methods is(427.87±2.01)fb^(-1).
