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
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
From April to July 2018,a data sample at the peak energy of the T(4 S) resonance was collected with the Belle Ⅱ detector at the SuperKEKB electron-positron collider.This is the first data sample of the Belle Ⅱ exper...From April to July 2018,a data sample at the peak energy of the T(4 S) resonance was collected with the Belle Ⅱ detector at the SuperKEKB electron-positron collider.This is the first data sample of the Belle Ⅱ experiment.Using Bhabha and digamma events,we measure the integrated luminosity of the data sample to be(496.3±0.3±3.0) pb-1,where the first uncertainty is statistical and the second is systematic.This work provides a basis for future luminosity measurements at Belle Ⅱ.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
Objective:A procedure has been proposed for patient-specific QA that,instead of comparing a measurement to the planned dose,compares the dose calculated by an independent system to the dose calculated by the planning ...Objective:A procedure has been proposed for patient-specific QA that,instead of comparing a measurement to the planned dose,compares the dose calculated by an independent system to the dose calculated by the planning system.It is still prudent,however,to check the accuracy of the beam delivery.For this purpose,the DICOM records from the first treatment fraction can be compared to the planned treatment using an in-house developed planning system.Methods:Totally 1,398 patient portals were subjected to the new QA procedure.The dose distribution for each portal was first recalculated on a water phantom by two treatment planning systems and the dose distributions were compared.When agreement was observed,the patient was allowed to start treatment without a measure-ment.The record from the first day was imported into an in-house planning system which was used to evaluate the delivery for errors and calculate the delivered dose distribution and compare it to the planned dose distribution.Results:A total of 266 portals passed a strict comparison between the clinical and QA dose calculations and directly used for treatment without measurements.For those portals,the comparison of the delivery records to the plan showed that 99%of spot positions deviated less than 0.2 mm and 99.7%of spot metersets deviated by less than 0.3%.On the other hand,64 portals showed spot size deviations greater than the tolerance of15%with some as large as25%.For 32 portals in which the record was used to calculate the delivered dose distribution,the Gamma passing rates between the planned and delivered distributions were always above 95%using a 2%dose difference and 2 mm distance-to-agreement criteria.Conclusions:The new QA process has been implemented slowly with strict constraints.The amount of beam time required has been reduced while maintaining safety.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 the following funding sources:Science Committee of the Republic of Armenia Grant No.18T-1C180Australian Research Council and research grant Nos.DP180102629,DP170102389,DP170102204,DP150103061,FT130100303,and FT130100018+37 种基金Austrian Federal Ministry of Education,Science and Research,and Austrian Science Fund No.P 31361-N36Natural Sciences and Engineering Research Council of Canada,Compute Canada and CANARIEChinese Academy of Sciences and research grant No.QYZDJ-SSW-SLH011National Natural Science Foundation of China and research grant Nos.11521505,11575017,11675166,11761141009,11705209,and 11975076LiaoNing Revitalization Talents Program under contract No.XLYC1807135Shanghai Municipal Science and Technology Committee under contract No.19ZR1403000Shanghai Pujiang Program under Grant No.18PJ1401000the CAS Center for Excellence in Particle Physics(CCEPP)the Ministry of Education,Youth and Sports of the Czech Republic under Contract No.LTT17020Charles University grants SVV260448 and GAUK 404316European Research Council,7th Framework PIEF-GA-2013-622527Horizon 2020 Marie Sklodowska-Curie grant agreement No.700525’NIOBE,’Horizon 2020 Marie Sklodowska-Curie RISE project JENNIFER grant agreement No.644294Horizon 2020 ERC-Advanced Grant No.267104NewAve No.638528(European grants)L’Institut National de Physique Nucléaire et de Physique des Particules(IN2P3)du CNRS(France),BMBF,DFG,HGF,MPG and AvH Foundation(Germany)Department of Atomic Energy and Department of Science and Technology(India)Israel Science Foundation grant No.2476/17United States-Israel Binational Science Foundation grant No.2016113Istituto Nazionale di Fisica Nucleare and the research grants BELLE2Japan Society for the Promotion of Science,Grant-in-Aid for Scientific Research grant Nos.16H03968,16H03993,16H06492,16K05323,17H01133,17H05405,18K03621,18H03710,18H05226,19H00682,26220706,and 26400255the National Institute of Informatics,and Science Information NETwork 5(SINET5)the Ministry of Education,Culture,Sports,Science,and Technology(MEXT)of JapanNational Research Foundation(NRF)of Korea Grant Nos.2016R1D1A1B01010135,2016R1D1A1B02012900,2018R1A2B3003643,2018R1A6A1A06024970,2018R1D1A1B07047294,2019K1A3A7A09033840,and 2019R1I1A3A01058933Radiation 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 contracts FOINS-296,CB-221329,CB-236394,CB-254409,and CB-180023,and the Thematic Networks program(Mexico)the Polish Ministry of Science and Higher Education and the National Science Centerthe Ministry of Science and Higher Education of the Russian Federation,Agreement14.W03.31.0026Slovenian Research Agency and research grant Nos.J1-9124 and P1-0135Agencia Estatal de Investigacion,Spain grant Nos.FPA2014-55613-P and FPA2017-84445-P,and CIDEGENT/2018/020 of Generalitat ValencianaMinistry of Science and Technology and research grant Nos.MOST106-2112-M-002-005-MY3 and MOST107-2119-M-002-035-MY3,and the Ministry of Education(Taiwan)Thailand Center of Excellence in PhysicsTUBITAK ULAKBIM(Turkey)Ministry of Education and Science of Ukrainethe US National Science Foundation and research grant Nos.PHY-1807007 and PHY-1913789the US Department of Energy and research grant Nos.DE-AC06-76RLO1830,DE-SC0007983,DE-SC0009824,DE-SC0009973,DE-SC0010073,DE-SC0010118,DE-SC0010504,DESC0011784,DE-SC0012704the National Foundation for Science and Technology Development(NAFOSTED)of Vietnam under grant No 103.99-2018.45
文摘From April to July 2018,a data sample at the peak energy of the T(4 S) resonance was collected with the Belle Ⅱ detector at the SuperKEKB electron-positron collider.This is the first data sample of the Belle Ⅱ experiment.Using Bhabha and digamma events,we measure the integrated luminosity of the data sample to be(496.3±0.3±3.0) pb-1,where the first uncertainty is statistical and the second is systematic.This work provides a basis for future luminosity measurements at Belle Ⅱ.
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.
文摘Objective:A procedure has been proposed for patient-specific QA that,instead of comparing a measurement to the planned dose,compares the dose calculated by an independent system to the dose calculated by the planning system.It is still prudent,however,to check the accuracy of the beam delivery.For this purpose,the DICOM records from the first treatment fraction can be compared to the planned treatment using an in-house developed planning system.Methods:Totally 1,398 patient portals were subjected to the new QA procedure.The dose distribution for each portal was first recalculated on a water phantom by two treatment planning systems and the dose distributions were compared.When agreement was observed,the patient was allowed to start treatment without a measure-ment.The record from the first day was imported into an in-house planning system which was used to evaluate the delivery for errors and calculate the delivered dose distribution and compare it to the planned dose distribution.Results:A total of 266 portals passed a strict comparison between the clinical and QA dose calculations and directly used for treatment without measurements.For those portals,the comparison of the delivery records to the plan showed that 99%of spot positions deviated less than 0.2 mm and 99.7%of spot metersets deviated by less than 0.3%.On the other hand,64 portals showed spot size deviations greater than the tolerance of15%with some as large as25%.For 32 portals in which the record was used to calculate the delivered dose distribution,the Gamma passing rates between the planned and delivered distributions were always above 95%using a 2%dose difference and 2 mm distance-to-agreement criteria.Conclusions:The new QA process has been implemented slowly with strict constraints.The amount of beam time required has been reduced while maintaining safety.
