Catalysis is an effective means to improve the slow kinetics of hydrogen absorption and desorption,as well as the poor cycle life of the 2LiBH_(4)+MgH_(2)composite system.In this study,the TiVC MXene was obtained by e...Catalysis is an effective means to improve the slow kinetics of hydrogen absorption and desorption,as well as the poor cycle life of the 2LiBH_(4)+MgH_(2)composite system.In this study,the TiVC MXene was obtained by etching TiVAlC and introduced into 2LiH+MgB_(2)by ball milling.Products obtained were heated and hydrogenated to prepare the 2LiBH_(4)+MgH_(2)(LMBH)system,which exhibits distinguished kinetic performance and capacity retention rate.In the LMBH+6 wt%TiVC,a 9.3 wt%hydrogen is released within 35 min at 400℃as well as hydrogenation is completed within 30 min at 350℃,9 MPa.Moreover,the capacity retention rate was up to 96%after the 15th cycle.During the heating and hydrogenation process,the TiH and V_(8)C_(7)are generated in-situ as active products,and stably exist in the subsequent process to catalyze the hydrogen absorption-desorption reactions of the composite.The presence of TiH/LiH/V_(8)C_(7)/MgB_(2)interface improves the kinetic performance of the system.Reversibility is improved by inhibiting the generation of polyborane and the aggregation during the hydrogen absorption-desorption process.The interface structure-activity relationship is first elucidated that between bimetallic MXene and 2LiBH_(4)+MgH_(2)composite system during hydrogen absorption-desorption processes,providing a novel viewpoint and optimization path for the modification research of 2LiBH_(4)+MgH_(2)composites.展开更多
随着多媒体通信技术的飞速发展,极低码率视频编码技术在众多领域中得到越来越多的重视。TIVC(TEMOBIINTELLIGENT VIDEO CODEC)是针对极低码率、无线信道的专用编码器。本文根据低码率/易错信道下信源编码的特点,从率控算法、率失真模型...随着多媒体通信技术的飞速发展,极低码率视频编码技术在众多领域中得到越来越多的重视。TIVC(TEMOBIINTELLIGENT VIDEO CODEC)是针对极低码率、无线信道的专用编码器。本文根据低码率/易错信道下信源编码的特点,从率控算法、率失真模型、易错信道下编码器的优化三个角度,详细介绍了TIVC编解码技术的算法体系。最后进行了TIVC在率失真性能和瞬时码率波动性能上的实验。实验结果显示TIVC更适用于低带宽、移动易错信道下的信源编码。展开更多
基金financed by the National Key Research and Development Plan of China[grants number 2021YFB3802400]the National Natural Science Foundation of China[grants number 52471225,52271212,52201250,51771056,52071141]Interdisciplinary Innovation Program of North China Electric Power University[grants number XM2112355].
文摘Catalysis is an effective means to improve the slow kinetics of hydrogen absorption and desorption,as well as the poor cycle life of the 2LiBH_(4)+MgH_(2)composite system.In this study,the TiVC MXene was obtained by etching TiVAlC and introduced into 2LiH+MgB_(2)by ball milling.Products obtained were heated and hydrogenated to prepare the 2LiBH_(4)+MgH_(2)(LMBH)system,which exhibits distinguished kinetic performance and capacity retention rate.In the LMBH+6 wt%TiVC,a 9.3 wt%hydrogen is released within 35 min at 400℃as well as hydrogenation is completed within 30 min at 350℃,9 MPa.Moreover,the capacity retention rate was up to 96%after the 15th cycle.During the heating and hydrogenation process,the TiH and V_(8)C_(7)are generated in-situ as active products,and stably exist in the subsequent process to catalyze the hydrogen absorption-desorption reactions of the composite.The presence of TiH/LiH/V_(8)C_(7)/MgB_(2)interface improves the kinetic performance of the system.Reversibility is improved by inhibiting the generation of polyborane and the aggregation during the hydrogen absorption-desorption process.The interface structure-activity relationship is first elucidated that between bimetallic MXene and 2LiBH_(4)+MgH_(2)composite system during hydrogen absorption-desorption processes,providing a novel viewpoint and optimization path for the modification research of 2LiBH_(4)+MgH_(2)composites.
文摘随着多媒体通信技术的飞速发展,极低码率视频编码技术在众多领域中得到越来越多的重视。TIVC(TEMOBIINTELLIGENT VIDEO CODEC)是针对极低码率、无线信道的专用编码器。本文根据低码率/易错信道下信源编码的特点,从率控算法、率失真模型、易错信道下编码器的优化三个角度,详细介绍了TIVC编解码技术的算法体系。最后进行了TIVC在率失真性能和瞬时码率波动性能上的实验。实验结果显示TIVC更适用于低带宽、移动易错信道下的信源编码。
