本文将基于Hellinger-Reissner广义变分原理,提出一种分析复合材料缠绕壳结构应力场分析的混合状态Hamilton元半解析法。该方法在周向面内采用有限元离散;而沿径向对状态方程进行解析求解。在求解过程中,采用了传递矩阵技术,以保证层间...本文将基于Hellinger-Reissner广义变分原理,提出一种分析复合材料缠绕壳结构应力场分析的混合状态Hamilton元半解析法。该方法在周向面内采用有限元离散;而沿径向对状态方程进行解析求解。在求解过程中,采用了传递矩阵技术,以保证层间位移和应力的连续性,并建立了缠绕结构的内、外表面状态变量之间的关系。为此,不论缠绕结构的层数有多少,最后都归结为求解缠绕结构内、外表面未知量。同常规位移有限元法相比,此方法大大地降低了求解未知量的数目。文中还采用Chang F K提出的复合材料缠绕结构的破坏准则,对一在服役工况下具有金属内衬的复合材料缠绕壳典型结构进行了强度校核。展开更多
采用混合溶剂法,通过改变钛酸四丁酯(TBOT)的量合成一系列不同比例的RF@TiO_2核-壳结构,于氮气气氛600℃下煅烧得到meso-C@TiO_2,进一步对所得产物表面进行贵金属沉积最终得到meso-C@TiO_2@Ag复合光催化剂。通过X射线衍射(XRD)、扫描电...采用混合溶剂法,通过改变钛酸四丁酯(TBOT)的量合成一系列不同比例的RF@TiO_2核-壳结构,于氮气气氛600℃下煅烧得到meso-C@TiO_2,进一步对所得产物表面进行贵金属沉积最终得到meso-C@TiO_2@Ag复合光催化剂。通过X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、全自动比表面积及微孔物理吸附仪(BET)等对样品的成份、形貌和结构进行了表征。结果表明,成功制备了meso-C@TiO_2@Ag三元介孔复合光催化材料,并且比表面积达到173.9 m^2/g。在可见光照射下,以降解亚甲基蓝为模型,探讨了TBOT用量以及Ag负载量对产物光催化性能的影响。研究发现,当加入TBOT的量为0.3 m L、AgNO_3的投入量为10wt%时,所制备的meso-C@TiO_2@Ag对亚甲基蓝的降解效果最佳,40 min内降解率接近100%,性能明显优于市售的纳米二氧化钛P25。展开更多
Due to the highly porous structure,large specific surface area,and 3 D interconnected metal conductive network,nanoporous metal foams have attracted a lot of attention in the field of energy conversion and storage,esp...Due to the highly porous structure,large specific surface area,and 3 D interconnected metal conductive network,nanoporous metal foams have attracted a lot of attention in the field of energy conversion and storage,especially lithium-ion batteries,which are ideal for current collectors.In this work,we develop a facile approach to fabricate core-shell Ni3Se2/Ni nanofoams composites.The Ni3Se2/Ni composites make full use of both the advantages of metal conductive network and core-shell structure,resulting in a high capacity and superior rate performance.In addition,the composites can be directly converted into electrode by a simple mechanical compression,which is more convenient than traditional casting method.What’s more,this material and its structure can be extended to other devices in the field of energy conversion and storage.展开更多
文摘本文将基于Hellinger-Reissner广义变分原理,提出一种分析复合材料缠绕壳结构应力场分析的混合状态Hamilton元半解析法。该方法在周向面内采用有限元离散;而沿径向对状态方程进行解析求解。在求解过程中,采用了传递矩阵技术,以保证层间位移和应力的连续性,并建立了缠绕结构的内、外表面状态变量之间的关系。为此,不论缠绕结构的层数有多少,最后都归结为求解缠绕结构内、外表面未知量。同常规位移有限元法相比,此方法大大地降低了求解未知量的数目。文中还采用Chang F K提出的复合材料缠绕结构的破坏准则,对一在服役工况下具有金属内衬的复合材料缠绕壳典型结构进行了强度校核。
文摘采用混合溶剂法,通过改变钛酸四丁酯(TBOT)的量合成一系列不同比例的RF@TiO_2核-壳结构,于氮气气氛600℃下煅烧得到meso-C@TiO_2,进一步对所得产物表面进行贵金属沉积最终得到meso-C@TiO_2@Ag复合光催化剂。通过X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、全自动比表面积及微孔物理吸附仪(BET)等对样品的成份、形貌和结构进行了表征。结果表明,成功制备了meso-C@TiO_2@Ag三元介孔复合光催化材料,并且比表面积达到173.9 m^2/g。在可见光照射下,以降解亚甲基蓝为模型,探讨了TBOT用量以及Ag负载量对产物光催化性能的影响。研究发现,当加入TBOT的量为0.3 m L、AgNO_3的投入量为10wt%时,所制备的meso-C@TiO_2@Ag对亚甲基蓝的降解效果最佳,40 min内降解率接近100%,性能明显优于市售的纳米二氧化钛P25。
基金financially supported by the Promotion Program for Young and Middle-aged Teacher in Science and Technology Research of Huaqiao University(ZQN-PY608)the Fujian Provincial Natural Science Foundation of China(No.2017J05008)the National Natural Science Foundation of China(No.11704071).
文摘Due to the highly porous structure,large specific surface area,and 3 D interconnected metal conductive network,nanoporous metal foams have attracted a lot of attention in the field of energy conversion and storage,especially lithium-ion batteries,which are ideal for current collectors.In this work,we develop a facile approach to fabricate core-shell Ni3Se2/Ni nanofoams composites.The Ni3Se2/Ni composites make full use of both the advantages of metal conductive network and core-shell structure,resulting in a high capacity and superior rate performance.In addition,the composites can be directly converted into electrode by a simple mechanical compression,which is more convenient than traditional casting method.What’s more,this material and its structure can be extended to other devices in the field of energy conversion and storage.
