Power losses caused by longitudinal HOMs in 1.3-GHz cryomodule of SHINE

Shanghai high-repetition-rate XFEL and extreme light facility (SHINE), the first hard XFEL based on a superconducting accelerated structure in China, is now under development at the Shanghai Institute of Applied Physics, Chinese Academy of Sciences. In this paper, power losses caused by trapped longitudinal high-order modes (HOM), steady-state loss, and transient loss generated by untrapped HOMs in the 1.3-GHz SHINE cryomodule are investigated and calculated. The heat load generated by resistive wall wakefields is considered as well. Results are presented for power losses of every element in the 1.3-GHz cryomodule, caused by HOM excitation in the acceleration RF system of the continuouswave linac of SHINE.

Recent Advances in 0D Ni/Co-based Hollow Electrocatalysts for Electrochemical Water Splitting

Electrochemical water splitting using renewable energy sources has been recognized as a sustainable way to produce hydrogen energy due to the characteristics of low-carbon and no pollution.However,the slow hydrogen/oxygen evolution reactions(HER/OER)seriously hinder the practical application of large-scale water splitting.In this paper,the 0D Ni/Co-based hollow material is discussed in detail because of adjustable morphology,low mass density and abundant active sites,which provides an effective solution for improving the HER/OER reaction kinetics.The synthesis methods of hollow materials,such as hard template,soft template and self-template are introduced.Afterward,catalysts with different structural designs of hollow structures are reviewed,including hollow single-shelled structure,hollow core-shelled structure,hollow double-shelled structure and hollow multi-shelled structure(HoMS)catalysts.Wherein,the research progress of the 0D Ni/Co-based HoMS electrocatalysts in recent years and their prominent performances in water splitting are highlighted.Finally,the challenges and development prospects of designing Ni/Co-based HoMS catalysts in water splitting in the future are discussed.

Boosting the Activity and Stability of the Photoreduction of Diluted CO_(2) by Copper Oxide Decorated CeO_(2) Hetero-shells

Inspired by the natural photosynthesis systems,the integrated harnessing and conversion of CO_(2) present a promising solution for addressing the ever-rising global atmospheric concentration of CO_(2).Hollow multi-shelled structured(HoMS)photocatalysts,featuring alternating shells and cavities,have recently gained recognition as efficient nano-reactors for capturing CO_(2) molecules and facilitating effective photoreduction within these hierarchical structures,leveraging the preeminent enrichment effect.In this work,to augment the photocatalytic efficacy of HoMS in CO_(2) treatment,highly dispersed Cu_(x)O nanoparticles(NPs)were incorporated on the CeO2 shells through a polymer-assisted impregnation method to create more active sites and strengthen the interaction between the hetero-shells and CO_(2) molecules.The photoreduction of the CO_(2)-to-CO rate under a diluted CO_(2)(15%,volume fraction)atmosphere is improved by the introduction of Cu_(x)O NPs,with the highest CO yielding rate reaching 120µmol·h^(−1)·g^(−1) without any sacrificial reagents.Further comparison experiments and theoretical calculations reveal that the Cu_(x)O NPs promote the adsorption of CO_(2) molecules in HoMS,accelerate the charge transfer efficiency,and stabilize the surface oxygen vacancies(Ovs)during the photoreduction CO_(2) conversion process.We hope these easy-to-prepare HoMS nanoreactors can contribute to the effective enrichment and valorization of CO_(2) in industrial exhaust gases.