Methane dehydroaromatization with periodic CH_4-H_2 switch:A promising process for aromatics and hydrogen

Long-term stability test of Mo/HZSM-5-N catalysts（HZSM-5-N stands for nano-sized HZSM-5） in methane dehydroaromatization（MDA）reaction has been performed with periodic CH4-H2 switch at 1033-1073 K for more than 1000 h.During this test,methane conversion ranges from 13% to 16%,and mean yield to aromatics（i.e.benzene and naphthalene） exceeds 10%.N2-physisorption,XRD,NMR and TPO measurements were performed for the used Mo/HZSM-5 catalysts and coke deposition,and the results revealed that the periodic hydrogenation can effectively suppress coke deposition by removing the inert aromatic-type coke,thus ensuring Mo/HZSM-5 partly maintained its activity even in the presence of large amount of coke deposition.The effect of zeolite particle size on the catalytic activity was also explored,and the results showed that the nano-sized zeolite with low diffusion resistance performed better.It is recognized that the size effect was enhanced by reaction time,and it became more remarkable in a long-term MDA reaction even at a low space velocity.

Design of high-performance and sustainable Co-free Ni-rich cathodes for next-generation lithium-ion batteries

Great attention has been given to high-performance and inexpensive lithiumion batteries(LIBs)in response to the ever-increasing demand for the explosive growth of electric vehicles(EVs).High-performance and low-cost Co-freeNi-rich layered cathodes are considered one of the most favorable candidates for nextgeneration LIBs because the current supply chain of EVs relies heavily on scarce and expensive Co.Herein,we review the recent research progress on Co-free Nirich layered cathodes,emphasizing on analyzing the necessity of replacing Co and the popular improvment methods.The current advancements in the design strategies of Co-free Ni-rich layered cathodes are summarized in detail.Despite considerable improvements achieved so far,the main technical challenges contributing to the deterioration of Co-free Ni-rich cathodes such as detrimental phase transitions,crack formation,and severe interfacial side reactions,are difficult to resolve by a single technique.The cooperation of multiple modification strategies is expected to accelerate the industrialization of Co-free Ni-rich layered cathodes,and the corresponding synergistic mechanisms urgently need to be studied.More effects will be aroused to explore high-performance Co-free Ni-rich layered cathodes to promote the sustainable development of LIBs.

Altered brain activity in juvenile myoclonic epilepsy with a monotherapy:a resting-state fMRI study

Background:Juvenile myoclonic epilepsy(JME)is the most common syndrome of idiopathic generalized epilepsy.Although resting-state functional magnetic resonance imaging(rs-fMRI)studies have found thalamocortical circuit dysfunction in patients with JME,the pathophysiological mechanism of JME remains unclear.In this study,we used three complementary parameters of rs-fMRI to investigate aberrant brain activity in JME patients in comparison to that of healthy controls.Methods:Rs-fMRI and clinical data were acquired from 49 patients with JME undergoing monotherapy and 44 ageand sex-matched healthy controls.After fMRI data preprocessing,the fractional amplitude of low-frequency fluctuation(fALFF),regional homogeneity(ReHo),and degree centrality(DC)were calculated and compared between the two groups.Correlation analysis was conducted to explore the relationship between local brain abnormalities and clinical features in JME patients.Results:Compared with the controls,the JME patients exhibited significantly decreased fALFF,ReHo and DC in the cerebellum,inferior parietal lobe,and visual cortex(including the fusiform and the lingual and middle occipital gyri),and increased DC in the right orbitofrontal cortex.In the JME patients,there were no regions with reduced ReHo compared to the controls.No significant correlation was observed between regional abnormalities of fALFF,ReHo or DC,and clinical features.Conclusions:We demonstrated a wide range of abnormal functional activity in the brains of patients with JME,including the prefrontal cortex,visual cortex,default mode network,and cerebellum.The results suggest dysfunctions of the cerebello-cerebral circuits,which provide a clue on the potential pathogenesis of JME.