Synthesis and electrochemical characteristics of xLi_2MnO_3·(1-x)Li(Ni_(1/3)Co_(1/3)Mn_(1/3))O_2 compounds

xLi2MnO3·（1-x）Li（Ni1/3Co1/3Mn1/3）O2 （x=0.25, 0.40, 0.55） compounds were prepared by low-heating solid state reaction. In the voltage range of 2.70-4.35 V, the discharge capacity of the electrode decreased with the increase of x, with a better cyclability. However, when cycled between 2.7 and 4.6 V, the cathodes delivered much larger capacities and their capacities increased with the introduction of Li2MnO3. Moreover, it was found that the discharge capacity gradually increased with the cycle number. The reason for this phenomenon was discussed. It was found that the relatively low cut-off potential made the activation of the Li2MnO3 component in the compound a gradual process, which caused the increasing capacity.

Middle Devonian ostracods from Jiwozhai patch reef(Dushan,Guizhou Province,South China):Biostratigraphic and palaeoecological implication

The Middle Devonian ostracods from the Jiwozhai patch reef in Dushan, Guizhou Province, South China were described for the first time in this study. Twenty-nine species belonging to 20 genera were identified and figured, including a new species named Wangshangkia jiwozhaiensis sp. nov. The ostracod fauna in the Jiwozhai patch reef represents a Givetian age. The ostracod assemblage belongs to the smooth-podocopid association, which is also ecologically equivalent to the Eifelian Mega-Assemblage Ⅲ. This association is indicative of shallow open-marine environments. The Jiwozhai patch reef fauna is primarily comprised of suspension feeders, including filter-feeding ostracods, corals, brachiopods and bryozoans. Ostracods from the Jiwozhai patch reef were compared to the ostracod faunas from Laurentia-Baltica at generic level, which reveals limited faunal exchanges between South China and Laurentia-Baltica during the Middle Devonian.

Silurian ostracods from the Nyalam region,southern Tibet,China and their implications on palaeoenvironment and palaeobiogeography

The overall occurrence,stratigraphical distribution,palaeoenvironmental and palaeobiogeographical significances of the ostracod faunas from the Silurian Pulu Formation in the Yalai West Ⅱ section,Nyalam region,southern Tibet,China,are documented for the first time.Thirty-two species belonging to 19 genera are identified and figured herein.The ostracod fauna in the Pulu Formation indicates an age of the late Llandovery-Pridoli.The ostracods belong to a podocope-rich association,which suggests an offshore environment for the Yalai West II section.The ostracods of the Pulu Formation have strong affinities with the South China taxa and also share some similarities with those from Baltica.This implies that ostracods could probably benefit from sea-level changes to facilitate faunal exchanges between peri-Gondwana and Baltica.Geographical isolation and global sea-level changes are proposed as the primary factors controlling the palaeobiogeographical distribution of ostracods during the Silurian.