The dehydroaramatization of methane over W-supported ZSM-5 with varying degrees of Li+ ion-exchanged catalysts was studied with and without oxygen at 1073 K and atmospheric pressure. Catalyst activity and stability we...The dehydroaramatization of methane over W-supported ZSM-5 with varying degrees of Li+ ion-exchanged catalysts was studied with and without oxygen at 1073 K and atmospheric pressure. Catalyst activity and stability were found to be influenced by the catalyst acidity related to Bronsted acid sites and by the presence of oxygen in the feed. The NH3-TPD and FTIR-pyridine results demonstrated that partially exchanged of H+ ions by Li+ into the W/HZSM-5 catalysts could be used to control the amount of strong acid sites on the catalyst surface. Without oxygen, the 3WHLi-Z (5:1) catalyst that has strong acid sites equal to nearly 74% of the original strong acid sites in the parent HZSM-5 exhibited the highest methane conversion and selectivity towards aromatics. However, the catalyst deactivated in a five hour period. In the presence of oxygen, the catalyst activity and stability could be improved further. The results of this study revealed that a suitable amount of strong Bronsted acid sites as well as oxygen addition in the feed increased the catalyst activity and stability. The 3WHLi-Z(5:1) catalyst exhibited improved performance in the dehydroaromatization of methane.展开更多
Objective:This study was designed to observe the effect of electroacupuncture at Hégǔ(合谷L14),or Hòuxī(后溪SI3) or Wàiguān(外关TE5) acupoints on the function of the brain regions of a healthy human,...Objective:This study was designed to observe the effect of electroacupuncture at Hégǔ(合谷L14),or Hòuxī(后溪SI3) or Wàiguān(外关TE5) acupoints on the function of the brain regions of a healthy human,and to explore the neural information mechanism of a specific connection between LI4 and the facialoral area from the point of view of the brain function connection network.A further objective was to enrich knowledge of the specific connection between the body surface and the meridian route,and the specificity of acupoint effects.Methods:A total of 30 healthy volunteers were randomly assigned to LI4,SI3,and TE5 groups.The members of each group were stimulated with electroacupuncture,and their heads were scanned using fMRI.DPARSFA 2.4 and REST 1.8 software were used for data preprocessing and statistical analysis.The paired t-test was used within group and the double sample t-test was used for two-group comparisons.Results:In healthy people,left LI4 with electroacupuncture mainly caused a decrease of the functional connection of the right orofacial motor area of the brain,which remained decreased after removing the needle.When LI4 was compared with SI3 and TE5,LI4 caused a more significant decline in the functional connection of the right side of the brain during acupuncture.Conclusions:Acupuncture at LI4 has a significant effect on the function of the face-and mouth-related areas in the brain,and there is a continuous effect.It is suggested that LI4 and the face and mouth have a specific relationship in the brain,which is most obvious during acupuncture.展开更多
对湖南省的油樟（Cinnamomum longepaniculatum (Gamble)N.Cho ex H.W.Li）资源作了调查。用色谱、色谱/质谱联用方法鉴定了油樟叶精油的43个化学成分,依主含成分不同可将其划分为6个不同的化学类型。其中,主含甲基丁香酚、龙脑、樟脑...对湖南省的油樟（Cinnamomum longepaniculatum (Gamble)N.Cho ex H.W.Li）资源作了调查。用色谱、色谱/质谱联用方法鉴定了油樟叶精油的43个化学成分,依主含成分不同可将其划分为6个不同的化学类型。其中,主含甲基丁香酚、龙脑、樟脑、芳樟醇和倍半萜烯的5个化学类型为首次在油樟中发现。展开更多
文摘The dehydroaramatization of methane over W-supported ZSM-5 with varying degrees of Li+ ion-exchanged catalysts was studied with and without oxygen at 1073 K and atmospheric pressure. Catalyst activity and stability were found to be influenced by the catalyst acidity related to Bronsted acid sites and by the presence of oxygen in the feed. The NH3-TPD and FTIR-pyridine results demonstrated that partially exchanged of H+ ions by Li+ into the W/HZSM-5 catalysts could be used to control the amount of strong acid sites on the catalyst surface. Without oxygen, the 3WHLi-Z (5:1) catalyst that has strong acid sites equal to nearly 74% of the original strong acid sites in the parent HZSM-5 exhibited the highest methane conversion and selectivity towards aromatics. However, the catalyst deactivated in a five hour period. In the presence of oxygen, the catalyst activity and stability could be improved further. The results of this study revealed that a suitable amount of strong Bronsted acid sites as well as oxygen addition in the feed increased the catalyst activity and stability. The 3WHLi-Z(5:1) catalyst exhibited improved performance in the dehydroaromatization of methane.
基金Supported by grants from National Key R&D Program of China:2019YFC1709001the National Natural Science Foundation of China:81973959+4 种基金8177443581674068the Foundation of Sichuan Provincial Administration of Traditional Chinese Medicine:2018JC007the Foundation of Chengdu University of Traditional Chinese Medicine:QNXZ2018034the National Program on Key Basic Research Project of China:2010CB530501.
文摘Objective:This study was designed to observe the effect of electroacupuncture at Hégǔ(合谷L14),or Hòuxī(后溪SI3) or Wàiguān(外关TE5) acupoints on the function of the brain regions of a healthy human,and to explore the neural information mechanism of a specific connection between LI4 and the facialoral area from the point of view of the brain function connection network.A further objective was to enrich knowledge of the specific connection between the body surface and the meridian route,and the specificity of acupoint effects.Methods:A total of 30 healthy volunteers were randomly assigned to LI4,SI3,and TE5 groups.The members of each group were stimulated with electroacupuncture,and their heads were scanned using fMRI.DPARSFA 2.4 and REST 1.8 software were used for data preprocessing and statistical analysis.The paired t-test was used within group and the double sample t-test was used for two-group comparisons.Results:In healthy people,left LI4 with electroacupuncture mainly caused a decrease of the functional connection of the right orofacial motor area of the brain,which remained decreased after removing the needle.When LI4 was compared with SI3 and TE5,LI4 caused a more significant decline in the functional connection of the right side of the brain during acupuncture.Conclusions:Acupuncture at LI4 has a significant effect on the function of the face-and mouth-related areas in the brain,and there is a continuous effect.It is suggested that LI4 and the face and mouth have a specific relationship in the brain,which is most obvious during acupuncture.
文摘对湖南省的油樟（Cinnamomum longepaniculatum (Gamble)N.Cho ex H.W.Li）资源作了调查。用色谱、色谱/质谱联用方法鉴定了油樟叶精油的43个化学成分,依主含成分不同可将其划分为6个不同的化学类型。其中,主含甲基丁香酚、龙脑、樟脑、芳樟醇和倍半萜烯的5个化学类型为首次在油樟中发现。
