This paper summarizes recent achievements in the characterization ofcandidate vanadium alloys obtained for fusion in the framework of the Japan-China Core UniversityProgram. National Institute for Fusion Science (NIFS...This paper summarizes recent achievements in the characterization ofcandidate vanadium alloys obtained for fusion in the framework of the Japan-China Core UniversityProgram. National Institute for Fusion Science (NIFS) has a program of fabricating high-purityV-4Cr-4Ti alloys. The resulting products (NIFS-HEAT-1,2), were characterized by various researchgroups in the world including Chinese partners. South Western Institute of Physics (SWIP) fabricateda new V-4Cr-4Ti alloy (SWIP-Heat), and carried out a comparative evaluation of hydrogenembrittlement of NIFS-HEATs and SWIP-Heat. The tensile test of hydrogen-doped alloys showed that theNIFS-HEAT maintained the ductility to relatively high hydrogen levels. The comparison of the datawith those of previous studies suggested that the reduced oxygen level in the NIFS-HEATs should beresponsible for the increased resistance to hydrogen embrittlement. Based on the chemical analysisdata of NIFS-HEATs and SWIP-Heats, neutron-induced activation was analyzed in Institute of PlasmaPhysics (IPP-CAS) as a function of cooling time after the use in the fusion first wall. The resultsshowed that the low level of Co dominates the activity up to 50 years followed by a domination of Nbor Nb and Al in the respective alloys. It was suggested that reduction of Co and Nb, both of whichare thought to have been introduced via cross-contamination into the alloys from the molds usedshould be crucial for reducing further the activation.展开更多
Comparison and validation of canopy reflectance(CR)models are two important steps to ensure their reliability.Pure forest plantations are an ideal type of forest for validating CR models because of their simple backgr...Comparison and validation of canopy reflectance(CR)models are two important steps to ensure their reliability.Pure forest plantations are an ideal type of forest for validating CR models because of their simple background and the low variance in the crown structures which are usually assumed to be identical in most CR models.A Geometric Optical Model for Forest Plantations(GOFP)was compared using dataset in two radiation transfer model intercomparison exercise(RAMI)stands and validated using in situ dataset of detailed optical and structural data of two forest plantations in the Saihanba Forestry Center,China.The results show that(1)the tree distributions in stands described by the hypergeometric model in GOFP show good consistencies with the dataset in the two RAMI stands and measurements from the two Saihanba forest stands;and(2)the CRs simulated with GOFP are also compared well in the two RAMI stands and validated with measurements collected with unmanned aerial vehicles in the two Saihanba stands.GOFP shows a better consistency with the CR measurements than those from CR models for natual forestsbecause the tree distribution in forest plantations is described more reasonably in GOFP.展开更多
基金The project supported by The Core-University Program on Plasma and Nuclear Fusion sponsored by JSPS(Japan)and CAS (China)
文摘This paper summarizes recent achievements in the characterization ofcandidate vanadium alloys obtained for fusion in the framework of the Japan-China Core UniversityProgram. National Institute for Fusion Science (NIFS) has a program of fabricating high-purityV-4Cr-4Ti alloys. The resulting products (NIFS-HEAT-1,2), were characterized by various researchgroups in the world including Chinese partners. South Western Institute of Physics (SWIP) fabricateda new V-4Cr-4Ti alloy (SWIP-Heat), and carried out a comparative evaluation of hydrogenembrittlement of NIFS-HEATs and SWIP-Heat. The tensile test of hydrogen-doped alloys showed that theNIFS-HEAT maintained the ductility to relatively high hydrogen levels. The comparison of the datawith those of previous studies suggested that the reduced oxygen level in the NIFS-HEATs should beresponsible for the increased resistance to hydrogen embrittlement. Based on the chemical analysisdata of NIFS-HEATs and SWIP-Heats, neutron-induced activation was analyzed in Institute of PlasmaPhysics (IPP-CAS) as a function of cooling time after the use in the fusion first wall. The resultsshowed that the low level of Co dominates the activity up to 50 years followed by a domination of Nbor Nb and Al in the respective alloys. It was suggested that reduction of Co and Nb, both of whichare thought to have been introduced via cross-contamination into the alloys from the molds usedshould be crucial for reducing further the activation.
基金funded by the National Natural Science Foundation of China(grant no.41701383,42071392,and 41801234)Anhui Provincial Natural Science Foundation(grant no.1808085QD105)+1 种基金the Fundamental Research Funds for the Central Universities of China(grant no.PA2020GDSK0083)the Fund of Key Laboratory of Information Perception and Systems forPublic Security of MIIT(Nanjing University of Science and Technology)(grant no.202003).
文摘Comparison and validation of canopy reflectance(CR)models are two important steps to ensure their reliability.Pure forest plantations are an ideal type of forest for validating CR models because of their simple background and the low variance in the crown structures which are usually assumed to be identical in most CR models.A Geometric Optical Model for Forest Plantations(GOFP)was compared using dataset in two radiation transfer model intercomparison exercise(RAMI)stands and validated using in situ dataset of detailed optical and structural data of two forest plantations in the Saihanba Forestry Center,China.The results show that(1)the tree distributions in stands described by the hypergeometric model in GOFP show good consistencies with the dataset in the two RAMI stands and measurements from the two Saihanba forest stands;and(2)the CRs simulated with GOFP are also compared well in the two RAMI stands and validated with measurements collected with unmanned aerial vehicles in the two Saihanba stands.GOFP shows a better consistency with the CR measurements than those from CR models for natual forestsbecause the tree distribution in forest plantations is described more reasonably in GOFP.
