2,633 research outputs found

    The First Sinomastodon (Gomphotheriidae, Proboscidea) Skull From the Quaternary in China

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    The first Sinomastodon (Gomphotheriidae, Proboscidea) skull of the Early Pleistocene, collected from the Renzidong Cave deposits in Anhui Province, Eastern China, is described here as S. jiangnanensis sp. nov. As the only brevirostrine trilophodont gomphotheriid known from the Old World, Sinomastodon was mainly indigenous to China from the Early Pliocene to the Pleistocene. Compared with a few single Pleistocene teeth previously found in China, S. jiangnanensis sp. nov. is represented by a relatively complete skull, mandible and dentition, which is the first discovery of a Quaternary Sinomastodon skull from China. With a brevirostrine, elephant-like skull, no lower tusks, and simple bunodont and trilophodont intermediate molars, the new species is morphologically distinct from other gomphotheres and should belong to the genus Sinomastodon. The new species is more progressive than S. hanjiangensis and the Pliocene type species S. intermedius in its skull and mandible morphology, but is evidently more primitive than the Pleistocene S. yangziensis in its molar morphology. The faunal analysis suggests that the emergence of S. jiangnanensis sp. nov. in Jiangnan area and its southward migration may have been related to a cooling event at the beginning of the Quaternary in Eastern China

    The First Sinomastodon (Gomphotheriidae, Proboscidea) Skull From the Quaternary in China

    Get PDF
    The first Sinomastodon (Gomphotheriidae, Proboscidea) skull of the Early Pleistocene, collected from the Renzidong Cave deposits in Anhui Province, Eastern China, is described here as S. jiangnanensis sp. nov. As the only brevirostrine trilophodont gomphotheriid known from the Old World, Sinomastodon was mainly indigenous to China from the Early Pliocene to the Pleistocene. Compared with a few single Pleistocene teeth previously found in China, S. jiangnanensis sp. nov. is represented by a relatively complete skull, mandible and dentition, which is the first discovery of a Quaternary Sinomastodon skull from China. With a brevirostrine, elephant-like skull, no lower tusks, and simple bunodont and trilophodont intermediate molars, the new species is morphologically distinct from other gomphotheres and should belong to the genus Sinomastodon. The new species is more progressive than S. hanjiangensis and the Pliocene type species S. intermedius in its skull and mandible morphology, but is evidently more primitive than the Pleistocene S. yangziensis in its molar morphology. The faunal analysis suggests that the emergence of S. jiangnanensis sp. nov. in Jiangnan area and its southward migration may have been related to a cooling event at the beginning of the Quaternary in Eastern China

    Terahertz Reconfigurable Metasurface for Dynamic Non-Diffractive Orbital Angular Momentum Beams using Vanadium Dioxide

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    Funding: This work was supported in part by the Natural Science Foundation of Beijing under Grant 4202047, in part by the Beijing Nova Program under Grant 181100006218039, and in part by the 111 Project (B17007). 10.13039/501100004826-Natural Science Foundation of Beijing Municipality (Grant Number: 4202047) 10.13039/501100005090-Beijing Nova Program (Grant Number: Z181100006218039) 10.13039/501100013314-Higher Education Discipline Innovation Project (Grant Number: B17007)Peer reviewedPublisher PD

    Configured Quantum Reservoir Computing for Multi-Task Machine Learning

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    Amidst the rapid advancements in experimental technology, noise-intermediate-scale quantum (NISQ) devices have become increasingly programmable, offering versatile opportunities to leverage quantum computational advantage. Here we explore the intricate dynamics of programmable NISQ devices for quantum reservoir computing. Using a genetic algorithm to configure the quantum reservoir dynamics, we systematically enhance the learning performance. Remarkably, a single configured quantum reservoir can simultaneously learn multiple tasks, including a synthetic oscillatory network of transcriptional regulators, chaotic motifs in gene regulatory networks, and the fractional-order Chua's circuit. Our configured quantum reservoir computing yields highly precise predictions for these learning tasks, outperforming classical reservoir computing. We also test the configured quantum reservoir computing in foreign exchange (FX) market applications and demonstrate its capability to capture the stochastic evolution of the exchange rates with significantly greater accuracy than classical reservoir computing approaches. Through comparison with classical reservoir computing, we highlight the unique role of quantum coherence in the quantum reservoir, which underpins its exceptional learning performance. Our findings suggest the exciting potential of configured quantum reservoir computing for exploiting the quantum computation power of NISQ devices in developing artificial general intelligence

    2,5-Dibenzoyl­benzene-1,4-diaminium dichloride

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    The asymmetric unit of the title compound, C20H18N2O2 2+·2Cl−, is composed of one-half of the 2,5-dibenzoyl­benzene-1,4-diaminium dication, located on a centre of inversion, and one Cl− ion. The dihedral angle between the central benzene ring and the benzoyl phenyl ring is 53.3 (2)°. In the crystal structure, ions are linked to form a two-dimensional network parallel to the (10) plane by N—H⋯Cl hydrogen bonds

    Structure and Magnetotransport Properties of Epitaxial Nanocomposite La0.67Ca0.33MnO3:SrTiO3 Thin Films Grown by a Chemical Solution Approach

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    Epitaxial La0.67Ca0.33MnO3:SrTiO3 (LCMO:STO) composite thin films have been grown on single crystal LaAlO3(001) substrates by a cost effective polymer-assisted deposition method. Both x-ray diffraction and high-resolution transmission electron microscopy confirm the growth of epitaxial films with an epitaxial relationship between the films and the substrates as (002)film||(002)sub and [202]film||[202]sub. The transport property measurement shows that the STO phase significantly increases the resistivity and enhances the magnetoresistance (MR) effect of LCMO and moves the metal-insulator transition to lower temperatures. For example, the MR values measured at magnetic fields of 0 and 3 T are −44.6% at 255 K for LCMO, −94.2% at 125 K for LCMO:3% STO, and −99.4% at 100 K for LCMO:5% STO, respectively

    Strongly-coupled nanotube electromechanical resonators

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    Coupling an electromechanical resonator with carbon-nanotube quantum dots is a significant method to control both the electronic charge and the spin quantum states. By exploiting a novel micro-transfer technique, we fabricate two strongly-coupled and electrically-tunable mechanical resonators on a single carbon nanotube for the first time. The frequency of the two resonators can be individually tuned by the bottom gates, and strong coupling is observed between the electron charge and phonon modes of each resonator. Furthermore, the conductance of either resonator can be nonlocally modulated by the phonon modes in the other resonator. Strong coupling is observed between the phonon modes of the two resonators, which provides an effective long distance electron-electron interaction. The generation of phonon-mediated-spin entanglement is also theoretically analyzed for the two resonators. This strongly-coupled nanotube electromechanical resonator array provides an experimental platform for future studies of the coherent electron-phonon interaction, the phonon mediated long-distance electron interaction, and entanglement state generation

    Structure and Magnetotransport Properties of Epitaxial Nanocomposite La0.67Ca0.33MnO3:SrTiO3 Thin Films Grown by a Chemical Solution Approach

    Get PDF
    Epitaxial La0.67Ca0.33MnO3:SrTiO3 (LCMO:STO) composite thin films have been grown on single crystal LaAlO3(001) substrates by a cost effective polymer-assisted deposition method. Both x-ray diffraction and high-resolution transmission electron microscopy confirm the growth of epitaxial films with an epitaxial relationship between the films and the substrates as (002)film||(002)sub and [202]film||[202]sub. The transport property measurement shows that the STO phase significantly increases the resistivity and enhances the magnetoresistance (MR) effect of LCMO and moves the metal-insulator transition to lower temperatures. For example, the MR values measured at magnetic fields of 0 and 3 T are −44.6% at 255 K for LCMO, −94.2% at 125 K for LCMO:3% STO, and −99.4% at 100 K for LCMO:5% STO, respectively
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