Aiming to elucidate the hydrogen absorption/desorption cycling properties of Mg-based alloys with in-situ formed Mg_(2)Ni and LaH_(x)(x=2,3)nanocrystallines,the hydrogen storage cycle stability,hydriding/dehydriding c...Aiming to elucidate the hydrogen absorption/desorption cycling properties of Mg-based alloys with in-situ formed Mg_(2)Ni and LaH_(x)(x=2,3)nanocrystallines,the hydrogen storage cycle stability,hydriding/dehydriding cycling kinetics and thermodynamic stability of the experimental alloys have been investigated in detail.The results show that the Mg-Ni-La alloys exhibit improved hydrogen storage cycling properties and can remain storage hydrogen above 5.5 wt%after 200 cycles.With the increase of cycling numbers,the dehydrogenation rates of the experimental samples increase firstly and then gradually decrease,and eventually maintain relative stable state.Microstructure observation reveals that powders sintering and hydrogen decrepitation both exist during hydrogen absorption/desorption cycles due to repeated volume expansion and contraction.Meanwhile,the in-situ formed LaH_(x)(x=2,3)and Mg_(2)Ni nanocrystallines stabilize the microstructures of the particles and hinder the powders sintering.After 200 cycles,the average particle size of the experimental samples decreases and the specific surface area apparently increases,which leads to the decomposition temperatures of MgH_(2)and Mg_(2)NiH_(4)slightly shift to lower temperatures.Moreover,Mg_(2)Ni and LaH_(x)(x=2,3)have been proven to be stable catalysts during long-term cycling,which can still uniformly distribute within the powders after 200 cycles.展开更多
当前,中国期刊界已经普遍认识到发表专刊/专栏可以提升期刊的影响力。《高等学校化学研究》(Chemical Research in Chinese Universities, CRCU)通过5年23期专刊/专栏的出版推动了期刊进步并积累了丰富的经验。本文从分析科技期刊评价...当前,中国期刊界已经普遍认识到发表专刊/专栏可以提升期刊的影响力。《高等学校化学研究》(Chemical Research in Chinese Universities, CRCU)通过5年23期专刊/专栏的出版推动了期刊进步并积累了丰富的经验。本文从分析科技期刊评价体系开始,指出了限制期刊发展的隐形圈子,通过引入X因素,详细解释了各种形式专刊/专栏能够破圈的原因。结合工作实践和诸多举例,让读者深入浅出的了解专刊/专栏出版的具体流程和关键步骤,可能遇到的问题和解决方案,最后强调了专刊出版后宣传工作的重要性,并结合期刊5年来的成果,给其他科技期刊组建专刊提供了针对性的建议。展开更多
背景:研究证实运动对多发性硬化症具有潜在的改善作用,但具体机制尚不完全清楚。目的:总结多发性硬化症患者的生理功能变化,探讨运动改善多发性硬化症患者生理功能的机制。方法:应用计算机检索Web of Science、PubMed、中国知网、万方...背景:研究证实运动对多发性硬化症具有潜在的改善作用,但具体机制尚不完全清楚。目的:总结多发性硬化症患者的生理功能变化,探讨运动改善多发性硬化症患者生理功能的机制。方法:应用计算机检索Web of Science、PubMed、中国知网、万方和维普数据库等,中文检索词为“多发性硬化症,脱髓鞘自身免疫疾病,运动,体育锻炼,神经退行性疾病”等,英文检索词为“Multiple sclerosis,Demyelinating Autoimmune Diseases,Exercise,Physical activity,Neurodegenerative diseases”等,文献检索时限为各数据库建库至2024年6月,根据预定的纳入和排除标准,最终筛选出81篇文献进行综述。结果与结论:多发性硬化症患者的生理和功能变化复杂多样,严重影响患者的生活质量和独立生活能力。运动作为一种非药物干预方式,在改善多发性硬化症患者的生理和功能状态方面显示出显著潜力,运动可以缓解疲劳、调节免疫反应、降低压力激素水平、增强血脑屏障功能及促进神经可塑性。然而,当前关于运动治疗多发性硬化症的具体机制研究仍然不足,需要更多高质量、系统性的研究来进一步验证和完善相关结论。未来的研究应聚焦于以下几个方面:进一步探索不同类型和强度运动对多发性硬化症患者生理功能和病情进展的具体影响,找出最适合多发性硬化症患者的运动方案;开展大规模、长期随访的临床试验,验证运动对多发性硬化症患者的长期效果和安全性;结合现代科技手段,如功能性磁共振成像和神经电生理技术,深入揭示运动干预对多发性硬化症患者神经系统的具体作用机制;考虑患者个体差异,制定个性化的运动干预方案,以最大程度地提高干预效果和患者依从性。展开更多
基金supported by Natural Science Foundation of Shaanxi Province,China(2017JM5079)The 111 project(No.B08040)is also acknowledged.
文摘Aiming to elucidate the hydrogen absorption/desorption cycling properties of Mg-based alloys with in-situ formed Mg_(2)Ni and LaH_(x)(x=2,3)nanocrystallines,the hydrogen storage cycle stability,hydriding/dehydriding cycling kinetics and thermodynamic stability of the experimental alloys have been investigated in detail.The results show that the Mg-Ni-La alloys exhibit improved hydrogen storage cycling properties and can remain storage hydrogen above 5.5 wt%after 200 cycles.With the increase of cycling numbers,the dehydrogenation rates of the experimental samples increase firstly and then gradually decrease,and eventually maintain relative stable state.Microstructure observation reveals that powders sintering and hydrogen decrepitation both exist during hydrogen absorption/desorption cycles due to repeated volume expansion and contraction.Meanwhile,the in-situ formed LaH_(x)(x=2,3)and Mg_(2)Ni nanocrystallines stabilize the microstructures of the particles and hinder the powders sintering.After 200 cycles,the average particle size of the experimental samples decreases and the specific surface area apparently increases,which leads to the decomposition temperatures of MgH_(2)and Mg_(2)NiH_(4)slightly shift to lower temperatures.Moreover,Mg_(2)Ni and LaH_(x)(x=2,3)have been proven to be stable catalysts during long-term cycling,which can still uniformly distribute within the powders after 200 cycles.
文摘当前,中国期刊界已经普遍认识到发表专刊/专栏可以提升期刊的影响力。《高等学校化学研究》(Chemical Research in Chinese Universities, CRCU)通过5年23期专刊/专栏的出版推动了期刊进步并积累了丰富的经验。本文从分析科技期刊评价体系开始,指出了限制期刊发展的隐形圈子,通过引入X因素,详细解释了各种形式专刊/专栏能够破圈的原因。结合工作实践和诸多举例,让读者深入浅出的了解专刊/专栏出版的具体流程和关键步骤,可能遇到的问题和解决方案,最后强调了专刊出版后宣传工作的重要性,并结合期刊5年来的成果,给其他科技期刊组建专刊提供了针对性的建议。
