Pristine LiNi0.5Mn1.5O4and Na-doped Li0.95Na0.05Ni0.5Mn1.5O4cathode materials were synthesized by a simple solid-statemethod.The effects of Na+doping on the crystalline structure and electrochemical performance of LiN...Pristine LiNi0.5Mn1.5O4and Na-doped Li0.95Na0.05Ni0.5Mn1.5O4cathode materials were synthesized by a simple solid-statemethod.The effects of Na+doping on the crystalline structure and electrochemical performance of LiNi0.5Mn1.5O4cathode materialwere systematically investigated.The samples were characterized by XRD,SEM,FT-IR,CV,EIS and galvanostatic charge/dischargetests.It is found that both pristine and Na-doped samples exhibit secondary agglomerates composed of well-defined octahedralprimary particle,but Na+doping decreases the primary particle size to certain extent.Na+doping can effectively inhibit the formationof LixNi1-xO impurity phase,enhance the Ni/Mn disordering degree,decrease the charge-transfer resistance and accelerate the lithiumion diffusion,which are conductive to the rate capability.However,the doped Na+ions tend to occupy8a Li sites,which forces equalamounts of Li+ions to occupy16d octahedral sites,making the spinel framework less stable,therefore the cycling stability is notimproved obviously after Na+doping.展开更多
Unambiguous and rapid sarcosaphagous insect species identification is an essential requirement for forensic investigations. Although some insect species are difficult to classify morphologically, they can be effective...Unambiguous and rapid sarcosaphagous insect species identification is an essential requirement for forensic investigations. Although some insect species are difficult to classify morphologically, they can be effectively identified using molecular methods based on similarity with abundant authenticated reference DNA sequences in local databases. However, local databases are still relatively incomplete in China because of the large land area with distinct regional conditions. In this study, 75 forensically important blow flies were collected from 23 locations in 16 Chinese provinces, and a 278-bp segment of the cytochrome oxidase subunit I gene of all specimens was successfully sequenced. Phylogenetic analysis of the sequenced segments showed that all Calliphorid specimens were properly assigned into nine species with relatively strong supporting values, thus indicating that the 278-bp cytochrome oxidase subunit one region is suitable for identification of Calliphorid species. The clear difference between intraspecific threshold and interspecific divergence confirmed the potential of this region for Calliphorid species identification, especially for distinguishing between morphologically similar species. Intraspecific geographic variations were observed in Lucilia sericata （Meigen, 1826） and Lucilia caesar （Linnaeus, 1758）.展开更多
基金Project(E2015202356)supported by the Natural Science Foundation of Hebei Province,ChinaProject(2013009)supported by the Technology Innovation Foundation for Outstanding Youth of Hebei University,China
文摘Pristine LiNi0.5Mn1.5O4and Na-doped Li0.95Na0.05Ni0.5Mn1.5O4cathode materials were synthesized by a simple solid-statemethod.The effects of Na+doping on the crystalline structure and electrochemical performance of LiNi0.5Mn1.5O4cathode materialwere systematically investigated.The samples were characterized by XRD,SEM,FT-IR,CV,EIS and galvanostatic charge/dischargetests.It is found that both pristine and Na-doped samples exhibit secondary agglomerates composed of well-defined octahedralprimary particle,but Na+doping decreases the primary particle size to certain extent.Na+doping can effectively inhibit the formationof LixNi1-xO impurity phase,enhance the Ni/Mn disordering degree,decrease the charge-transfer resistance and accelerate the lithiumion diffusion,which are conductive to the rate capability.However,the doped Na+ions tend to occupy8a Li sites,which forces equalamounts of Li+ions to occupy16d octahedral sites,making the spinel framework less stable,therefore the cycling stability is notimproved obviously after Na+doping.
文摘Unambiguous and rapid sarcosaphagous insect species identification is an essential requirement for forensic investigations. Although some insect species are difficult to classify morphologically, they can be effectively identified using molecular methods based on similarity with abundant authenticated reference DNA sequences in local databases. However, local databases are still relatively incomplete in China because of the large land area with distinct regional conditions. In this study, 75 forensically important blow flies were collected from 23 locations in 16 Chinese provinces, and a 278-bp segment of the cytochrome oxidase subunit I gene of all specimens was successfully sequenced. Phylogenetic analysis of the sequenced segments showed that all Calliphorid specimens were properly assigned into nine species with relatively strong supporting values, thus indicating that the 278-bp cytochrome oxidase subunit one region is suitable for identification of Calliphorid species. The clear difference between intraspecific threshold and interspecific divergence confirmed the potential of this region for Calliphorid species identification, especially for distinguishing between morphologically similar species. Intraspecific geographic variations were observed in Lucilia sericata （Meigen, 1826） and Lucilia caesar （Linnaeus, 1758）.
