High-rate Gamma Spectrometry Using a LaBr3(Ce)Scintillator with a Fast Pulse Shaping.Tianyi Ren1,2,Soo Hyun Byun1,2(1.Department of Physics and Astronomy,McMaster University,Hamilton,ON,L8S 4K1,Canada;2.Radiation Scie...High-rate Gamma Spectrometry Using a LaBr3(Ce)Scintillator with a Fast Pulse Shaping.Tianyi Ren1,2,Soo Hyun Byun1,2(1.Department of Physics and Astronomy,McMaster University,Hamilton,ON,L8S 4K1,Canada;2.Radiation Sciences Graduate Program,McMaster University,Hamilton,ON,L8S 4K1,Canada)Abstract:The performance of a LaBr_(3)(Ce)gamma spectrometer at high count rates was investigated up to an input count rate of 1.3 Mcps.In order to make its pulse processing faster,a preamplifier provided by the detector manufacturer was eliminated,and the signal from the photomultiplier tubewas fed directly to a digital pulse processing system.展开更多
Selective conversion of fructose to 1,2-propanediol(1,2-PDO)is considered as a sustainable and cost-effective alternative to petroleum-based processes,however,this approach still faces challenges associated with low e...Selective conversion of fructose to 1,2-propanediol(1,2-PDO)is considered as a sustainable and cost-effective alternative to petroleum-based processes,however,this approach still faces challenges associated with low efficiency and harsh reaction conditions.Here,we have successfully synthesized a novel bifunctional Ru-WO_(x)-MgO_(y) catalyst through a facile'one-pot'solvothermal method.Remarkably,this catalyst exhibits exceptional catalytic performances in the conversion of fructose to 1,2-PDO under mild reaction conditions.The yield of 1,2-PDO is up to 56.2%at 140°C for 4 h under an ultra-low hydrogen pressure of only 0.2 MPa,surpassing the reported results in recent literature(below 51%).Comprehensive characterizations and density functional theory(DFT)calculations reveal that the presence of oxygen vacancies in the Ru-WO_(x)-MgO_(y) catalyst,serving as active acidic sites,facilitates the chemoselective cleavage of C-C bonds in fructose,which leads to the generation of active intermediates and ultimately resulted in the high yield of 1,2-PDO.展开更多
文摘High-rate Gamma Spectrometry Using a LaBr3(Ce)Scintillator with a Fast Pulse Shaping.Tianyi Ren1,2,Soo Hyun Byun1,2(1.Department of Physics and Astronomy,McMaster University,Hamilton,ON,L8S 4K1,Canada;2.Radiation Sciences Graduate Program,McMaster University,Hamilton,ON,L8S 4K1,Canada)Abstract:The performance of a LaBr_(3)(Ce)gamma spectrometer at high count rates was investigated up to an input count rate of 1.3 Mcps.In order to make its pulse processing faster,a preamplifier provided by the detector manufacturer was eliminated,and the signal from the photomultiplier tubewas fed directly to a digital pulse processing system.
基金the financial support from the Natural Science Foundation of Chongqing(CSTB2022NSCQ-MSX0458)the State Key Laboratory of Coal Mine Disaster Dynamics and Control(2011DA105287-MS202203)+4 种基金the Joint Fund for Innovation and Development of Chongqing(CSTB2022NSCQ-LZX0030)the financial support from the National Natural Science Foundation of China(22168027 and 22308169)the financial support from the Natural Science Foundation of Chongqing(cstc2021jcyj-msxmX0741)the financial support from the National Natural Science Foundation of China(22105028)the Natural Science Foundation of Chongqing(cstc2021jcyj-msxmX0572)。
文摘Selective conversion of fructose to 1,2-propanediol(1,2-PDO)is considered as a sustainable and cost-effective alternative to petroleum-based processes,however,this approach still faces challenges associated with low efficiency and harsh reaction conditions.Here,we have successfully synthesized a novel bifunctional Ru-WO_(x)-MgO_(y) catalyst through a facile'one-pot'solvothermal method.Remarkably,this catalyst exhibits exceptional catalytic performances in the conversion of fructose to 1,2-PDO under mild reaction conditions.The yield of 1,2-PDO is up to 56.2%at 140°C for 4 h under an ultra-low hydrogen pressure of only 0.2 MPa,surpassing the reported results in recent literature(below 51%).Comprehensive characterizations and density functional theory(DFT)calculations reveal that the presence of oxygen vacancies in the Ru-WO_(x)-MgO_(y) catalyst,serving as active acidic sites,facilitates the chemoselective cleavage of C-C bonds in fructose,which leads to the generation of active intermediates and ultimately resulted in the high yield of 1,2-PDO.
