The^(74)Se is one of 35 p-nuclei,and^(82)Se is a r-process only nucleus,and their(n,γ)cross sections are vital input parameters for nuclear astrophysics reaction network calculations.The neutron capture cross section...The^(74)Se is one of 35 p-nuclei,and^(82)Se is a r-process only nucleus,and their(n,γ)cross sections are vital input parameters for nuclear astrophysics reaction network calculations.The neutron capture cross section in the resonance range of isotopes and even natural selenium samples has not been measured.Promptγ-rays originating from neutron-induced capture events were detected by four C_(6)D_(6) liquid scintillator detectors at the Back-n facility of China Spallation Neutron Source(CSNS).The pulse height weighting technique(PHWT)was used to analyze the data in the 1 e V to 100 ke V region.The deduced neutron capture cross section was compared with ENDF/B-VIII.0,JEFF-3.2,and JENDL-4.0,and some differences were found.Resonance parameters were extracted by the R-matrix code SAMMY in the 1 e V-1 ke V region.All the cross sections ofnatSe and resonance parameters are given in the datasets.The datasets are openly available at http://www.doi.org/10.11922/sciencedb.j00113.00019.展开更多
DFT/BLYP method is used to theoretically investigate the electron transfer (ET) reactions between M (Li, Na, Mg)-C_6H_6 and M+-C_6H_6 complexes in the gas phase. The geometry optimization of the precursor complexes an...DFT/BLYP method is used to theoretically investigate the electron transfer (ET) reactions between M (Li, Na, Mg)-C_6H_6 and M+-C_6H_6 complexes in the gas phase. The geometry optimization of the precursor complexes and the transition state in the process of ET reaction was performed at 6-31G basis set level. The activation energy. the coupling matrix element and the rate constant of the ET reaction are calculated at semi-quantitative level.展开更多
Sodium-ion batteries(SIBs)are regarded as the ideal low-cost choice for next-generation large-scale energy storage system.Carbonyl-based organic salt-disodium rhodizonate(Na_(2)C_(6)O_(6))with high theoretical specifi...Sodium-ion batteries(SIBs)are regarded as the ideal low-cost choice for next-generation large-scale energy storage system.Carbonyl-based organic salt-disodium rhodizonate(Na_(2)C_(6)O_(6))with high theoretical specific capacity(501 mAh·g−1)is considered as a promising cathode material for SIBs.However,the dissolution of active material in electrolyte and low electronic conductivity lead to rapidly capacity decay and poor rate performance.Herein,a simple method is designed to construct free-standing and flexible Ti3C2Tx Na2C6O6/MXene paper via vacuum-assisted filtration and antisolvent approach.The MXene can form an electronic conductive network,adsorb the active materials,and offer additional active sites for Na storage.The binder-free Na_(2)C_(6)O_(6)/MXene paper delivers excellent electrochemical property with a high rate performance of 231 mAh·g−1 at 1,000 mA·g−1 and a high capacity of 215 mAh·g−1 after 100 cycles.This work provides an attractive strategy for designing high-performance organic electrode materials of SIBs.展开更多
The neutron capture cross section of 197 Au was measured using the time-of-flight(TOF)technique at the Back-n facility of the China Spallation Neutron Source(CSNS)in the 1 eV to 100 keV range.Prompt c-rays originating...The neutron capture cross section of 197 Au was measured using the time-of-flight(TOF)technique at the Back-n facility of the China Spallation Neutron Source(CSNS)in the 1 eV to 100 keV range.Prompt c-rays originating from neutron-induced capture events were detected by four C_(6)D_(6) liquid scintillator detectors.Pulse height weighting technology(PHWT)was used to analyze the data.The results are in good agreement with ENDF/B-VIII.0,CENDL-3.1,and other evaluated libraries in the resonance region,and in agreement with both n TOF and GELINA experimental data in the 5–100 keV range.Finally,the resonance peaks in the energy range from 1eV to 1 keV were fitted by the SAMMY R-matrix code.展开更多
The neutron capture cross section of ^(232)Th was measured at the neutron time-of-flight facility Back-n of China Spallation Neutron Source(CSNS)for the first time.The measurement was performed with 4 hydrogen-free de...The neutron capture cross section of ^(232)Th was measured at the neutron time-of-flight facility Back-n of China Spallation Neutron Source(CSNS)for the first time.The measurement was performed with 4 hydrogen-free deuterated benzene C6D6 liquid scintillation detectors,in the ES#2 experiment station on the beam line,at a distance of about 76 m from the neutron-production assembly.The total energy detection principle in combination with the pulse height weighting technique(PHWT)was applied to analyze the measured data.Results of the ^(232)Th(n,γ)reaction cross section in the unresolved resonance region from 4 keV to 100 keV were obtained,which shows a good agreement with the existing experimental data from EXFOR,as well as with the evaluated data from the ENDF/B-VIII.0 and CENDL-3.1.In addition,the excitation function of ^(232)Th(n,γ)^(233)Th reaction in the unresolved resonance region was theoretically calculated by using the code TALYS-1.95.By fitting the experimental cross section and theoretical data,the average parameters in the unresolved resonance region were extracted.展开更多
Electrocatalytic nitrogen reduction reaction(NRR)is an environmentally friendly method for sustainable ammonia synthesis under ambient conditions.Searching for efficient NRR electrocatalysts with high activity and sel...Electrocatalytic nitrogen reduction reaction(NRR)is an environmentally friendly method for sustainable ammonia synthesis under ambient conditions.Searching for efficient NRR electrocatalysts with high activity and selectivity is currently urgent but remains great challenge.Herein,we systematically investigate the NRR catalytic activities of single and double transition metal atoms(TM=Fe,Co,Ni and Mo)anchored on g-C_(6)N_(6) monolayers by performing first-principles calculation.Based on the stability,activity,and selectivity analysis,Mo_(2)@g-C_(6)N_(6) monolayer is screened out as the most promising candidate for NRR.Further exploration of the reaction mechanism demonstrates that the Mo dimer anchored on g-C_(6)N_(6) can sufficiently activate and efficiently reduce the inert nitrogen molecule to ammonia through a preferred distal pathway with a particularly low limiting potential of -0.06 V.In addition,we find that Mo_(2)@g-C_(6)N_(6) has excellent NRR selectivity over the competing hydrogen evolution reaction,with the Faradaic efficiency being 100%.Our work not only predicts a kind of ideal NRR electrocatalyst but also encouraging more experimental and theoretical efforts to develop novel double-atom catalysts(DACs)for NRR.展开更多
The identification of highly abundant,“magic”spe-cies in the mass spectra of clusters have proven to be valuable in nanoscience,leading to the discovery of new stable species such as fullerenes and the elec-tronic s...The identification of highly abundant,“magic”spe-cies in the mass spectra of clusters have proven to be valuable in nanoscience,leading to the discovery of new stable species such as fullerenes and the elec-tronic shell structures of metallic clusters.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.11875311,11905274,11705156,11605097,and U2032146)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB34030000)。
文摘The^(74)Se is one of 35 p-nuclei,and^(82)Se is a r-process only nucleus,and their(n,γ)cross sections are vital input parameters for nuclear astrophysics reaction network calculations.The neutron capture cross section in the resonance range of isotopes and even natural selenium samples has not been measured.Promptγ-rays originating from neutron-induced capture events were detected by four C_(6)D_(6) liquid scintillator detectors at the Back-n facility of China Spallation Neutron Source(CSNS).The pulse height weighting technique(PHWT)was used to analyze the data in the 1 e V to 100 ke V region.The deduced neutron capture cross section was compared with ENDF/B-VIII.0,JEFF-3.2,and JENDL-4.0,and some differences were found.Resonance parameters were extracted by the R-matrix code SAMMY in the 1 e V-1 ke V region.All the cross sections ofnatSe and resonance parameters are given in the datasets.The datasets are openly available at http://www.doi.org/10.11922/sciencedb.j00113.00019.
基金the Natural Science Foundation of Shandong Pro\incethe National Kc' Laboratory' Foundation of Crustal Material the Natio
文摘DFT/BLYP method is used to theoretically investigate the electron transfer (ET) reactions between M (Li, Na, Mg)-C_6H_6 and M+-C_6H_6 complexes in the gas phase. The geometry optimization of the precursor complexes and the transition state in the process of ET reaction was performed at 6-31G basis set level. The activation energy. the coupling matrix element and the rate constant of the ET reaction are calculated at semi-quantitative level.
基金This work was supported by the Natural Science Foundation of Shandong Province(No.ZR2020JQ19)Taishan Scholars Program of Shandong Province(Nos.tsqn201812002,ts20190908,and ts201511004)+2 种基金the Young Scholars Program of Shandong University(No.2016WLJH03)Shenzhen Fundamental Research Program(No.JCYJ20190807093405503)the National Natural Science Foundation of China(Nos.51972198 and 61633015).
文摘Sodium-ion batteries(SIBs)are regarded as the ideal low-cost choice for next-generation large-scale energy storage system.Carbonyl-based organic salt-disodium rhodizonate(Na_(2)C_(6)O_(6))with high theoretical specific capacity(501 mAh·g−1)is considered as a promising cathode material for SIBs.However,the dissolution of active material in electrolyte and low electronic conductivity lead to rapidly capacity decay and poor rate performance.Herein,a simple method is designed to construct free-standing and flexible Ti3C2Tx Na2C6O6/MXene paper via vacuum-assisted filtration and antisolvent approach.The MXene can form an electronic conductive network,adsorb the active materials,and offer additional active sites for Na storage.The binder-free Na_(2)C_(6)O_(6)/MXene paper delivers excellent electrochemical property with a high rate performance of 231 mAh·g−1 at 1,000 mA·g−1 and a high capacity of 215 mAh·g−1 after 100 cycles.This work provides an attractive strategy for designing high-performance organic electrode materials of SIBs.
基金supported by the National Natural Science Foundation of China(Nos.11875311,11905274,11705156,and 11605097)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB34030000)。
文摘The neutron capture cross section of 197 Au was measured using the time-of-flight(TOF)technique at the Back-n facility of the China Spallation Neutron Source(CSNS)in the 1 eV to 100 keV range.Prompt c-rays originating from neutron-induced capture events were detected by four C_(6)D_(6) liquid scintillator detectors.Pulse height weighting technology(PHWT)was used to analyze the data.The results are in good agreement with ENDF/B-VIII.0,CENDL-3.1,and other evaluated libraries in the resonance region,and in agreement with both n TOF and GELINA experimental data in the 5–100 keV range.Finally,the resonance peaks in the energy range from 1eV to 1 keV were fitted by the SAMMY R-matrix code.
基金supported by the Chinese TMSR Strategic Pioneer Science and Technology Project(Grant No.XDA02010000)the National Natural Science Foundation of China(Grant No.11790321).
文摘The neutron capture cross section of ^(232)Th was measured at the neutron time-of-flight facility Back-n of China Spallation Neutron Source(CSNS)for the first time.The measurement was performed with 4 hydrogen-free deuterated benzene C6D6 liquid scintillation detectors,in the ES#2 experiment station on the beam line,at a distance of about 76 m from the neutron-production assembly.The total energy detection principle in combination with the pulse height weighting technique(PHWT)was applied to analyze the measured data.Results of the ^(232)Th(n,γ)reaction cross section in the unresolved resonance region from 4 keV to 100 keV were obtained,which shows a good agreement with the existing experimental data from EXFOR,as well as with the evaluated data from the ENDF/B-VIII.0 and CENDL-3.1.In addition,the excitation function of ^(232)Th(n,γ)^(233)Th reaction in the unresolved resonance region was theoretically calculated by using the code TALYS-1.95.By fitting the experimental cross section and theoretical data,the average parameters in the unresolved resonance region were extracted.
基金supported by the Science&Technology Development Fund of Tianjin Education Commission for Higher Education(No.2020KJ008)the Natural Science Foundation of Tianjin(No.18JCQNJC76000)+3 种基金the College Students'Innovation and Entrepreneurship Training Program of Tianjin(No.202110065112)Science and Technology Research Project of Hubei Provincial De-partment of Education(No.D20212603)Hubei University of Arts and Science(Nos.2020kypytd002,XK2021024)China Scholarship Council.
文摘Electrocatalytic nitrogen reduction reaction(NRR)is an environmentally friendly method for sustainable ammonia synthesis under ambient conditions.Searching for efficient NRR electrocatalysts with high activity and selectivity is currently urgent but remains great challenge.Herein,we systematically investigate the NRR catalytic activities of single and double transition metal atoms(TM=Fe,Co,Ni and Mo)anchored on g-C_(6)N_(6) monolayers by performing first-principles calculation.Based on the stability,activity,and selectivity analysis,Mo_(2)@g-C_(6)N_(6) monolayer is screened out as the most promising candidate for NRR.Further exploration of the reaction mechanism demonstrates that the Mo dimer anchored on g-C_(6)N_(6) can sufficiently activate and efficiently reduce the inert nitrogen molecule to ammonia through a preferred distal pathway with a particularly low limiting potential of -0.06 V.In addition,we find that Mo_(2)@g-C_(6)N_(6) has excellent NRR selectivity over the competing hydrogen evolution reaction,with the Faradaic efficiency being 100%.Our work not only predicts a kind of ideal NRR electrocatalyst but also encouraging more experimental and theoretical efforts to develop novel double-atom catalysts(DACs)for NRR.
基金The financial support for this work was provided by the National Natural Science Foundation of China(grant no.21722308 and 21802146)by Beijing Natural Science Foundation(2192064)+1 种基金by the National Project Development of Advanced Scientific Instruments Based on Deep Ultraviolet Laser Source(no.Y31M0112C1)by Key Research Program of Frontier Sciences(CAS,Grant QYZDBSSW-SLH024).
文摘The identification of highly abundant,“magic”spe-cies in the mass spectra of clusters have proven to be valuable in nanoscience,leading to the discovery of new stable species such as fullerenes and the elec-tronic shell structures of metallic clusters.
