Relative fibular/tibial strength has been demonstrated to vary with locomotor behavior among anthropoid primates. In this study fibular/tibial strength was determined in KNM-WT 15000, a juvenile Homo ...erectus individual (1.5 Ma), and in OH 35, a Homo habilis (or possibly Paranthropus boisei) individual (1.8 Ma), and compared to that of adult modern humans (n = 79), chimpanzees (n = 16), gorillas (n = 16) and orangutans (n = 11). Ontogenetic changes in fibular/tibial strength were also analyzed due to KNM-WT 15000's juvenile status. Cross-sectional properties at midshaft were derived from multi-plane radiography and external contours, or CT scanning. Comparisons of log-transformed fibular/tibial polar second moment of area and anteroposterior (A-P) and mediolateral (M-L) second moments of area were carried out between extant species. Fossil deviations from each extant taxon's mean proportion were calculated in standard deviation (SD) units for that taxon. Great apes differ significantly from modern humans, with relatively stronger fibulae, particularly in the M-L plane. KNM-WT 15000 is more than 2 SD from all great apes (≥3 SD in the M-L plane) and within 1 SD of modern humans for almost all variables. This is not a result of its age, as fibular/tibial strength slightly decreases with age (i.e., becomes less like that of great apes) in humans. OH 35 falls within 1 SD of chimpanzees and orangutans for the majority of cross-sectional proportions, but more than 1 SD from humans. KNM-WT 15000 is demonstrated to be fully modern, complimenting other indications of complete terrestrial bipedality and possibly showing adaptations for endurance running. OH 35 has some human-like features; however, the relative strength of the two bones aligns the specimen with great apes, consistent with a significant degree of arboreality, in particular, vertical climbing.
Paranthropus boisei was first described in 1959 based on fossils from the Olduvai Gorge and now includes many fossils from Ethiopia to Malawi. Knowledge about its postcranial anatomy has remained ...elusive because, until recently, no postcranial remains could be reliably attributed to this taxon. Here, we report the first associated hand and upper limb skeleton (KNM-ER 47000) of P. boisei from 1.51 to 1.53 Ma sediments at Ileret, Kenya. While the fossils show a combination of primitive and derived traits, the overall anatomy is characterized by primitive traits that resemble those found in Australopithecus, including an oblique scapular spine, relatively long and curved ulna, lack of third metacarpal styloid process, gracile thumb metacarpal, and curved manual phalanges. Very thick cortical bone throughout the upper limb shows that P. boisei had great upper limb strength, supporting hypotheses that this species spent time climbing trees, although probably to a lesser extent than earlier australopiths. Hand anatomy shows that P. boisei, like earlier australopiths, was capable of the manual dexterity needed to create and use stone tools, but lacked the robust thumb of Homo erectus, which arguably reflects adaptations to the intensification of precision grips and tool use. KNM-ER 47000 provides conclusive evidence that early Pleistocene hominins diverged in postcranial and craniodental anatomy, supporting hypotheses of competitive displacement among these contemporaneous hominins.
Sodium-ion batteries (SIBs) have received tremendous attention owing to their low cost, high working voltages, and energy density. However, the design and development of highly efficient SIBs ...represent a great challenge. Here, a unique and reliable approach is reported to prepare carbon nitride (CN) hybridized with nickel iron sulfide (NFCN) using simple reaction between Ni-Fe layered double hydroxide and dithiooxamide. The characterization results demonstrate that the hybridization with optimal amount of CN induces local distortion in the crystal structure of the hybrid, which would benefit SIB performance. Systematic electrochemical studies with a half-cell configuration show that the present hybrid structure exhibits a promising reversible specific capacity of 348 mAh g
at 0.1 A g
after 100 cycles with good rate capability. Simulation result reveals that the iron atoms in nickel iron sulfide act as a primary active site to accommodate Na
ions. At last, with a full cell configuration using NFCN and Na
V
(PO
)
O
F as the anode and cathode, respectively, the specific capacity appears to be ≈95 mAh g
after 50 cycles at 0.1 A g
condition. This excellent performance of these hybrids can be attributed to the synergistic effect of the incorporated CN species and the high conductivity of nickel-iron sulfide.
N‐rich carbon nitride (CN) is a promising framework that can generate innovative hybrid structures for energy applications. However, the low thermal stability of N atoms in the CN matrix is a major ...drawback as the crystallization of the hybridized counterpart requires a high temperature. Herein, we report the successful synthesis of the hybrid of N‐rich CN and Fe1‐xS at 700 °C by constructing a stable C−N−Fe−S heterointerface using a Fe‐incorporated metal‐organic framework (MOF) and dithiooxamide containing C, N and S atoms. The hybrids display promising capacities toward Li+ and Na+ ions storage, highlighting the beneficial role of N‐rich CN on battery performance. By systematically investigating their structure and electrochemical properties, we show that N‐rich CN, along with the heterointerface, not only acts as a hybridization matrix that helps facilitate the charge transfer kinetics but also generates substantial capacity. This unique study reveals a powerful platform for the rational design of N‐rich CN based hybrids from MOF.
Construction of C−N−Fe−S heterointerface (HI) via MOF‐templating method leads to successful synthesis of N‐rich carbon nitride (CN)‐Fe1‐xS hybrid at 700 °C. The hybrids outweigh the performance of CN‐based structures by delivering capacities of ∼1750 and ∼300 mAh g−1 for Li‐ion and Na‐ion batteries. The performance is due to critical role of N‐rich CN with HI which not only acts as hybridization matrix but also contributes on capacity.
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