A novel Ti-doped M-site deficient olivine LiFePO4, i.e. Li0.95Fe0.95Ti0.05PO4, was synthesized by a solid-state reaction method. XRD and VTR were used to characterize the as-prepared samples. As a cathode material for...A novel Ti-doped M-site deficient olivine LiFePO4, i.e. Li0.95Fe0.95Ti0.05PO4, was synthesized by a solid-state reaction method. XRD and VTR were used to characterize the as-prepared samples. As a cathode material for lithium-ion batteries, Li0.95Fe0.95Ti0.05PO4 exhibited improved rate capability.展开更多
利用1989—1996年滇西地震预报实验场绝对重力和相对重力观测资料,采用逐年差分和多年累积的方法,分析滇西地震预报实验场内部不同时间尺度的重力场演变特征及其与丽江地震在时空上的对应关系,结果表明:①1992年以前,研究区内部重力场...利用1989—1996年滇西地震预报实验场绝对重力和相对重力观测资料,采用逐年差分和多年累积的方法,分析滇西地震预报实验场内部不同时间尺度的重力场演变特征及其与丽江地震在时空上的对应关系,结果表明:①1992年以前,研究区内部重力场变化平稳,1993年出现局部变化,1995年变化急剧加大,震后快速反向调整,变化量值基本与震前多年累积相当,重力场演化特征与丽江地震存在高度时空对应关系,表明该时段重力场变化为丽江地震的孕震特征。②研究区差分及累积重力场动态演化过程中,在川滇菱形块体与滇西块体边界产生重力变化梯度带,表明这2个块体构造活动剧烈。③沿红河断裂带出现(-60~90)×10-8 m/s 2的重力变化高梯度带,其走向与红河断裂构造高度一致,反映区域重力场变化受主要活动构造控制,是地下深部壳幔物质运移的表现。展开更多
Molecular sieves of SAPO-41 with different silicon contents were synthesized and characterized by XRD,N2 adsorption,XRF,pyridine-IR and 29SiMAS-NMR.The isomerization properties of the SAPO-41 were investigated by usin...Molecular sieves of SAPO-41 with different silicon contents were synthesized and characterized by XRD,N2 adsorption,XRF,pyridine-IR and 29SiMAS-NMR.The isomerization properties of the SAPO-41 were investigated by using m-xylene as a feedstock.The SAPO-41 obtained from the synthesis gel with SiO2/Al2O3=0.3 showed the highest activity to the isomerization of m-xylene and the largest number of Brnsted acid sites was also observed with Py-IR over this sample.The state of Si in the framework of SAPO-41 plays a predominant role on the Brnsted acidity.The relationship between the activity and the acidity obtained in this study can be explained in terms of the distribution of stronger Brnsted acid sites.展开更多
文摘A novel Ti-doped M-site deficient olivine LiFePO4, i.e. Li0.95Fe0.95Ti0.05PO4, was synthesized by a solid-state reaction method. XRD and VTR were used to characterize the as-prepared samples. As a cathode material for lithium-ion batteries, Li0.95Fe0.95Ti0.05PO4 exhibited improved rate capability.
文摘利用1989—1996年滇西地震预报实验场绝对重力和相对重力观测资料,采用逐年差分和多年累积的方法,分析滇西地震预报实验场内部不同时间尺度的重力场演变特征及其与丽江地震在时空上的对应关系,结果表明:①1992年以前,研究区内部重力场变化平稳,1993年出现局部变化,1995年变化急剧加大,震后快速反向调整,变化量值基本与震前多年累积相当,重力场演化特征与丽江地震存在高度时空对应关系,表明该时段重力场变化为丽江地震的孕震特征。②研究区差分及累积重力场动态演化过程中,在川滇菱形块体与滇西块体边界产生重力变化梯度带,表明这2个块体构造活动剧烈。③沿红河断裂带出现(-60~90)×10-8 m/s 2的重力变化高梯度带,其走向与红河断裂构造高度一致,反映区域重力场变化受主要活动构造控制,是地下深部壳幔物质运移的表现。
文摘Molecular sieves of SAPO-41 with different silicon contents were synthesized and characterized by XRD,N2 adsorption,XRF,pyridine-IR and 29SiMAS-NMR.The isomerization properties of the SAPO-41 were investigated by using m-xylene as a feedstock.The SAPO-41 obtained from the synthesis gel with SiO2/Al2O3=0.3 showed the highest activity to the isomerization of m-xylene and the largest number of Brnsted acid sites was also observed with Py-IR over this sample.The state of Si in the framework of SAPO-41 plays a predominant role on the Brnsted acidity.The relationship between the activity and the acidity obtained in this study can be explained in terms of the distribution of stronger Brnsted acid sites.
