Due to its numerous environmental extremes, the Tibetan Plateau-the world's highest plateau-is one of the most challenging areas of modern human settlement. Archaeological evidence dates the earliest settlement on the plateau to the Late Paleolithic, while previous genetic studies have traced the colonization event(s) to no earlier than the Neolithic. To explore whether the genetic continuity on the plateau has an exclusively Neolithic time depth, we studied mitochondrial DNA (mtDNA) genome variation within 6 regional Tibetan populations sampled from Tibet and neighboring areas. Our results confirm that the vast majority of Tibetan matrilineal components can trace their ancestry to Epipaleolithic and Neolithic immigrants from northern China during the midHolocene. Significantly, we also identified an infrequent novel haplogroup, M16, that branched off directly from the Eurasian M founder type. Its nearly exclusive distribution in Tibetan populations and ancient age (>21 kya) suggest that M16 may represent the genetic relics of the Late Paleolithic inhabitants on the plateau. This partial genetic continuity between the Paleolithic inhabitants and the contemporary Tibetan populations bridges the results and inferences from archaeology, history, and genetics.mtDNA ͉ origin

No abstract

No abstract

Spherical LiNi0.8Co0.15Al0.05O2 (LNCA) cathode material with excellent electrochemical performance for lithium-ion batteries is successfully synthesized with the precursor of Ni0.8Co0.15Al0.05(OH)2 (NCA) prepared from a continuous co-precipitation method. A more environmentally friendly chelating agent, 5-sulfosalicylic acid (SSA, H3L), stabile as well as non-toxic, is firstly adapted in our synthesis process instead of traditional NH3·H 2O. Thermodynamics of the precipitation from the Ni(II)-Co(II)-Al(III)-SSA-H2O system at 298 K are systematically investigated through thermodynamics model analysis. The results demonstrate that stoichiometric spherical Ni0.8Co0.15Al0.05(OH)2 precursor can be obtained at pH=11~13, with the SSA concentration from 0.05mol L -1 to 0.5mol L -1 . LiNi0.8Co0.15Al0.05O2 prepared from the precursor has an initial discharge specific capacity of 203.1mAh g -1 at 0.1C and capacity retention of 93.3% after 200 cycles when cycled at 1 C between 3.0 and 4.3 V, as well as excellent rate capability. The electrochemical performances are superior to that prepared by using ammonia as chelating agent. It is expected that LiNi0.8Co0.15Al0.05O2 cathode material can be synthesized by a more environmentally friendly method.Please do not adjust margins Please do not adjust margins Scheme1. Prepare Ni0.8Co0.15Al0.05(OH)2 by the co-precipitation method using SSA as chelating agent.

No abstract