采用一步水热法合成Nb_2O_5和Fe(Ⅲ)掺杂的五氧化二铌微纳米球(Fe-Nb_2O_5),并利用X射线衍射(XRD)、扫描电子显微镜(SEM)及透射电子显微镜(TEM)等测试手段分别对其结构和形貌进行了表征。结果发现,所合成的Fe-Nb_2O_5和Nb_2O_5均为正交...采用一步水热法合成Nb_2O_5和Fe(Ⅲ)掺杂的五氧化二铌微纳米球(Fe-Nb_2O_5),并利用X射线衍射(XRD)、扫描电子显微镜(SEM)及透射电子显微镜(TEM)等测试手段分别对其结构和形貌进行了表征。结果发现,所合成的Fe-Nb_2O_5和Nb_2O_5均为正交晶相,Nb_2O_5为尺寸分布在50~300 nm之间的形貌不规则颗粒,而Fe-Nb_2O_5是由约50 nm的一次颗粒自组装而成的直径约为1μm的均匀微纳米球,即具有多级结构,其有利于增大电极材料与电解液的接触界面。电化学测试结果表明,Fe-Nb_2O_5的循环稳定性和倍率性能得到明显改善,在50 m A·g^(-1)电流密度下,100次循环后放电容量仍保持在193.2 m Ah·g^(-1),即使在5 A·g^(-1)的电流密度下,容量仍可达到108.4 m Ah·g^(-1)。并分析了其性能改善的原因。展开更多
including octupole correlations in the Nilsson potential,the ground-state rotational bands in the reflection-asymmetric(RA)nuclei are investigated by using the cranked shell model(CSM)with the monopole and quadrupole ...including octupole correlations in the Nilsson potential,the ground-state rotational bands in the reflection-asymmetric(RA)nuclei are investigated by using the cranked shell model(CSM)with the monopole and quadrupole pairing correlations treated by a particle-number-conserving(PNC)method.The experimental kinematic moments ofinertia(Mols)for alternating-parity bands in the even-even nuclei 236238U and 238.240Pu,as well as paritydoublet bands in the odd-A nuclei 237U and 239Pu are reproduced well by the PNC-CSM calculations.The higher J(1)for the intrinsic s=-i bands in 237U and 239Pu,compared with the s=+1 bands in the neighboring even-even nuclei 236.238U and 238.240Pu,can be attributed to the pairing gap reduction due to the Pauli blocking effect.The gradual increase of J(i)versus rotational frequency can be explained by the pairing gap reduction due to the rotation.The Mols of reflection-asymmetric nuclei are higher than those of reflection-symmetric(RS)nuclei at low rotational frequency.Moreover,the inclusion of a larger octupole deformation 8,in the RA nuclei results in more significant pairing gap reduction compared with the RS nuclei.展开更多
文摘采用一步水热法合成Nb_2O_5和Fe(Ⅲ)掺杂的五氧化二铌微纳米球(Fe-Nb_2O_5),并利用X射线衍射(XRD)、扫描电子显微镜(SEM)及透射电子显微镜(TEM)等测试手段分别对其结构和形貌进行了表征。结果发现,所合成的Fe-Nb_2O_5和Nb_2O_5均为正交晶相,Nb_2O_5为尺寸分布在50~300 nm之间的形貌不规则颗粒,而Fe-Nb_2O_5是由约50 nm的一次颗粒自组装而成的直径约为1μm的均匀微纳米球,即具有多级结构,其有利于增大电极材料与电解液的接触界面。电化学测试结果表明,Fe-Nb_2O_5的循环稳定性和倍率性能得到明显改善,在50 m A·g^(-1)电流密度下,100次循环后放电容量仍保持在193.2 m Ah·g^(-1),即使在5 A·g^(-1)的电流密度下,容量仍可达到108.4 m Ah·g^(-1)。并分析了其性能改善的原因。
文摘including octupole correlations in the Nilsson potential,the ground-state rotational bands in the reflection-asymmetric(RA)nuclei are investigated by using the cranked shell model(CSM)with the monopole and quadrupole pairing correlations treated by a particle-number-conserving(PNC)method.The experimental kinematic moments ofinertia(Mols)for alternating-parity bands in the even-even nuclei 236238U and 238.240Pu,as well as paritydoublet bands in the odd-A nuclei 237U and 239Pu are reproduced well by the PNC-CSM calculations.The higher J(1)for the intrinsic s=-i bands in 237U and 239Pu,compared with the s=+1 bands in the neighboring even-even nuclei 236.238U and 238.240Pu,can be attributed to the pairing gap reduction due to the Pauli blocking effect.The gradual increase of J(i)versus rotational frequency can be explained by the pairing gap reduction due to the rotation.The Mols of reflection-asymmetric nuclei are higher than those of reflection-symmetric(RS)nuclei at low rotational frequency.Moreover,the inclusion of a larger octupole deformation 8,in the RA nuclei results in more significant pairing gap reduction compared with the RS nuclei.
