天然气-二氧化碳-水蒸气-氧转化制合成气的研究－稀土助剂的作用

研究了稀土氧化物（CeO2和La2O3)改性的镍基催化剂中助剂的作用，并考察了催化剂对天然气－二氧化碳－水蒸气－氧转化制合成气反应的活性,结果表明，La2O3改性的镍基催化剂具有较高的CH4转化率和H2选择性；经CeO2改性的镍基催化剂具有较高的 CO选择性，量子化学计算和XRD研究结果表明，La2O3助剂的加入，可使还原化催化剂表面Ni(111)晶面衍射峰的强度减小，较好地符合吸附活化CH4分子的“尺寸效应”和能量要求，添加CeO2助剂的催化剂，其Ni(111）晶面衍射峰强度较大，而Ni（110）晶面含量最小，不利地CH4的离解，同时，助剂RE2O3（尤其是CeO2）和MgO提高了Ni的d电子密度，因而一定程度上加强度了Nid电子向CO2空反键π轨道的迁移，促进CO2分子的活化，其消碳活性

天然气-二氧化碳-水蒸气-氧转化制合成气的研究－稀土助剂的作用

研究了稀土氧化物（CeO2和La2O3)改性的镍基催化剂中助剂的作用，并考察了催化剂对天然气－二氧化碳－水蒸气－氧转化制合成气反应的活性,结果表明，La2O3改性的镍基催化剂具有较高的CH4转化率和H2选择性；经CeO2改性的镍基催化剂具有较高的 CO选择性，量子化学计算和XRD研究结果表明，La2O3助剂的加入，可使还原化催化剂表面Ni(111)晶面衍射峰的强度减小，较好地符合吸附活化CH4分子的“尺寸效应”和能量要求，添加CeO2助剂的催化剂，其Ni(111）晶面衍射峰强度较大，而Ni（110）晶面含量最小，不利地CH4的离解，同时，助剂RE2O3（尤其是CeO2）和MgO提高了Ni的d电子密度，因而一定程度上加强度了Nid电子向CO2空反键π轨道的迁移，促进CO2分子的活化，其消碳活性

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel

JUNO sensitivity on proton decay p → ν K + searches*

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this study, the potential of searching for proton decay in the $p\to \bar{\nu} K^+$ mode with JUNO is investigated. The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar{\nu} K^+$ is 36.9% ± 4.9% with a background level of $0.2\pm 0.05({\rm syst})\pm$$0.2({\rm stat})$ events after 10 years of data collection. The estimated sensitivity based on 200 kton-years of exposure is $9.6 \times 10^{33}$ years, which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies