Phase transitions involving oxygen ion extraction within the framework of the crystallographic relevance have been widely exploited for sake of superconductivity,ferromagnetism,and ion conductivity in perovskiterelate...Phase transitions involving oxygen ion extraction within the framework of the crystallographic relevance have been widely exploited for sake of superconductivity,ferromagnetism,and ion conductivity in perovskiterelated oxides.However,atomic-scale pathways of phase transitions and ion extraction threshold are inadequately understood.Here we investigate the atomic structure evolution of LaCoO_(3) films upon oxygen extraction and subsequent Co migration,focusing on the key role of epitaxial strain.The brownmillerite to Ruddlesden-Popper phase transitions are discovered to stabilize at distinct crystal orientations in compressive-and tensile-strained cobaltites,which could be attributed to in-plane and out-of-plane Ruddlesden-Popper stacking faults,respectively.A two-stage process from exterior to interior phase transition is evidenced in compressive-strained LaCoO_(2.5),while a single-step nucleation process leaving bottom layer unchanged in tensile-strained situation.Strain analyses reveal that the former process is initiated by an expansion in Co layer at boundary,whereas the latter one is associated with an edge dislocation combined with antiphase boundary.These findings provide a chemomechanical perspective on the structure regulation of perovskite oxides and enrich insights into strain-dependent phase diagram in epitaxial oxides films.展开更多
In Na-ion batteries,O3-type layered oxide cathode materials encounter challenges such as particle cracking,oxygen loss,electrolyte side reactions,and multi-phase transitions during the charge/discharge process.This st...In Na-ion batteries,O3-type layered oxide cathode materials encounter challenges such as particle cracking,oxygen loss,electrolyte side reactions,and multi-phase transitions during the charge/discharge process.This study focuses on surface coating with NiTiO_(3) achieved via secondary heat treatment using a coating precursor and the surface material.Through in-situ x-ray diffraction(XRD)and differential electrochemical mass spectrometry(DEMS),along with crystal structure characterizations of post-cycling materials,it was determined that the NiTiO_(3) coating layer facilitates the formation of a stable lattice structure,effectively inhibiting lattice oxygen loss and reducing side reaction with the electrolyte.This enhancement in cycling stability was evidenced by a capacity retention of approximately 74%over 300 cycles at 1 C,marking a significant 30%improvement over the initial sample.Furthermore,notable advancements in rate performance were observed.Experimental results indicate that a stable and robust surface structure substantially enhances the overall stability of the bulk phase,presenting a novel approach for designing layered oxide cathodes with higher energy density.展开更多
In this theoretical work,we describe a mechanism for the coupling between a plane structure consisting of four quantum dots and a resonator.We systematically study the dependence of the quadruple coupling strength and...In this theoretical work,we describe a mechanism for the coupling between a plane structure consisting of four quantum dots and a resonator.We systematically study the dependence of the quadruple coupling strength and the qubit decoherence rate and point out the optimized operating position of the hybrid system.According to the transmission given by the input-output theory,the signatures in the resonator spectrum are predicted.Furthermore,based on the parameters already achieved in previous works,we prove that the device described in this paper can achieve the strong coupling limit,i.e.,this approach can be used for system extension under the existing technical conditions.Our results show an effective and promotable approach to couple quantum dot structures in plane with the resonator and propose a meaningful extension method.展开更多
目的:通过运用Meta分析评价痛泻要方治疗腹泻型肠易激综合征的临床疗效。方法:检索2016年以前有关痛泻要方治疗腹泻型肠易激综合征的临床试验性研究文献,采用Jadad质量计分法对纳入的研究进行质量评价,运用Rev Man 5.3.0软件进行Meta分...目的:通过运用Meta分析评价痛泻要方治疗腹泻型肠易激综合征的临床疗效。方法:检索2016年以前有关痛泻要方治疗腹泻型肠易激综合征的临床试验性研究文献,采用Jadad质量计分法对纳入的研究进行质量评价,运用Rev Man 5.3.0软件进行Meta分析。结果:最终将纳入的符合标准的7篇文献进行异质性检验:χ2=1.96,P=0.92>0.1,I2=0%,可使用固定模式进行Meta分析,合并效应量OR值为4.17,可信区间95%CI(2.62,6.65),P<0.00001,差异有统计学意义,治疗组疗效优于对照组。倒置的"漏斗图"显示未见明显的发表偏倚。结论:痛泻要方治疗腹泻型肠易激综合征的临床疗效显著,但纳入的研究文献均为小样本文献,方法学质量评价不高,故仍需大量的多样本的、多中心的随机对照试验(RCT)进行进一步的证实。展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.52322212,52072400,52025025,and 52250402)。
文摘Phase transitions involving oxygen ion extraction within the framework of the crystallographic relevance have been widely exploited for sake of superconductivity,ferromagnetism,and ion conductivity in perovskiterelated oxides.However,atomic-scale pathways of phase transitions and ion extraction threshold are inadequately understood.Here we investigate the atomic structure evolution of LaCoO_(3) films upon oxygen extraction and subsequent Co migration,focusing on the key role of epitaxial strain.The brownmillerite to Ruddlesden-Popper phase transitions are discovered to stabilize at distinct crystal orientations in compressive-and tensile-strained cobaltites,which could be attributed to in-plane and out-of-plane Ruddlesden-Popper stacking faults,respectively.A two-stage process from exterior to interior phase transition is evidenced in compressive-strained LaCoO_(2.5),while a single-step nucleation process leaving bottom layer unchanged in tensile-strained situation.Strain analyses reveal that the former process is initiated by an expansion in Co layer at boundary,whereas the latter one is associated with an edge dislocation combined with antiphase boundary.These findings provide a chemomechanical perspective on the structure regulation of perovskite oxides and enrich insights into strain-dependent phase diagram in epitaxial oxides films.
基金Project supported by the National Key R&D Program of China (Grant No.2022YFB2402500)the National Natural Science Foundation of China (Grant Nos.52122214,92372116,and 52394174)+2 种基金Youth Innovation Promotion Association of the Chinese Academy of Sciences (Grant No.2020006)Jiangsu Province Carbon Peak and Neutrality Innovation Program (Industry tackling on prospect and key technology BE2022002-5)Guangxi Power Grid Project (Grant No.GXKJXM20210260)。
文摘In Na-ion batteries,O3-type layered oxide cathode materials encounter challenges such as particle cracking,oxygen loss,electrolyte side reactions,and multi-phase transitions during the charge/discharge process.This study focuses on surface coating with NiTiO_(3) achieved via secondary heat treatment using a coating precursor and the surface material.Through in-situ x-ray diffraction(XRD)and differential electrochemical mass spectrometry(DEMS),along with crystal structure characterizations of post-cycling materials,it was determined that the NiTiO_(3) coating layer facilitates the formation of a stable lattice structure,effectively inhibiting lattice oxygen loss and reducing side reaction with the electrolyte.This enhancement in cycling stability was evidenced by a capacity retention of approximately 74%over 300 cycles at 1 C,marking a significant 30%improvement over the initial sample.Furthermore,notable advancements in rate performance were observed.Experimental results indicate that a stable and robust surface structure substantially enhances the overall stability of the bulk phase,presenting a novel approach for designing layered oxide cathodes with higher energy density.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.92265113,12074368,and 12034018).
文摘In this theoretical work,we describe a mechanism for the coupling between a plane structure consisting of four quantum dots and a resonator.We systematically study the dependence of the quadruple coupling strength and the qubit decoherence rate and point out the optimized operating position of the hybrid system.According to the transmission given by the input-output theory,the signatures in the resonator spectrum are predicted.Furthermore,based on the parameters already achieved in previous works,we prove that the device described in this paper can achieve the strong coupling limit,i.e.,this approach can be used for system extension under the existing technical conditions.Our results show an effective and promotable approach to couple quantum dot structures in plane with the resonator and propose a meaningful extension method.
文摘目的:通过运用Meta分析评价痛泻要方治疗腹泻型肠易激综合征的临床疗效。方法:检索2016年以前有关痛泻要方治疗腹泻型肠易激综合征的临床试验性研究文献,采用Jadad质量计分法对纳入的研究进行质量评价,运用Rev Man 5.3.0软件进行Meta分析。结果:最终将纳入的符合标准的7篇文献进行异质性检验:χ2=1.96,P=0.92>0.1,I2=0%,可使用固定模式进行Meta分析,合并效应量OR值为4.17,可信区间95%CI(2.62,6.65),P<0.00001,差异有统计学意义,治疗组疗效优于对照组。倒置的"漏斗图"显示未见明显的发表偏倚。结论:痛泻要方治疗腹泻型肠易激综合征的临床疗效显著,但纳入的研究文献均为小样本文献,方法学质量评价不高,故仍需大量的多样本的、多中心的随机对照试验(RCT)进行进一步的证实。
