Publications by authors named "Yanyao Zhang"

Hydrous aluminosilicates are important deep water-carriers in sediments subducting into the deep mantle. To date, it remains enigmatic how hydrous aluminosilicates withstand extremely high temperatures in the mantle transition zone. Here we systematically investigate the crystal structures and chemical compositions of typical hydrous aluminosilicates using single-crystal X-ray diffraction, electron probe microanalyzer, and nanoscale secondary ion mass spectrometry.

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Carbon materials display intriguing physical properties, including superconductivity and highly anisotropic thermal conductivity found in graphene. Compressive strain can induce structural and bonding transitions in carbon materials and create new carbon phases, but their interplay with thermal conductivity remains largely unexplored. We investigated the in situ high-pressure thermal conductivity of compressed graphitic phases using picosecond transient thermoreflectance and first-principles calculations.

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Article Synopsis
  • The study investigates the local structure and physical properties of molten silicates under extreme conditions, which are important for understanding planetary evolution.
  • Researchers used advanced techniques like in situ X-ray diffraction and high-power lasers to analyze shock-compressed liquid silicates with varying iron content at extremely high pressures.
  • Findings suggest that the densification of silicate networks continues beyond pressures found in Earth's interior, potentially affecting the formation and differentiation of rocky planets and super-Earths.
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The complete mitochondrial genome of Leech, 1889 was sequenced and annotated in this study, which was the first reported complete mitogenome of the genus . The mitogenome of is 15,305 bp in length and was predicted to encode 37 typical mitochondrial genes including 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNAs), 2 ribosomal RNA genes (rRNAs), and one major non-coding A-T rich region. The maximum likelihood phylogenetic analysis based on the 13 PCGs was constructed, including and 15 related Spilomelinae species, using as the outgroup.

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Stimuli-responsive polymers with changeable fluorescent properties have numerous applications in sensing, bioimaging, and detection. Here we describe the facile synthesis of a pH-responsive amphiphilic asymmetric diblock copolymer of acrylic acid and butyl acrylate that incorporates a polarity-sensitive fluorophore. The asymmetric structure enhances the stimuli-responsive behavior: as the environmental pH decreases, the fluorescent intensity of the asymmetric diblock copolymer gradually increases, whereas its symmetric block counterpart shows limited and stepwise change.

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Elastic moduli (C_{ij}) of single-crystal stishovite and post-stishovite are determined using Brillouin light scattering, impulsive stimulated light scattering, and x-ray diffraction up to 70 GPa. The C_{12} of stishovite converges with the C_{11} at ∼55  GPa, where the transverse wave V_{S1} propagating along [110] also vanishes. Landau modeling of the C_{ij}, B_{1g} optic mode, and lattice parameters reveals a pseudoproper type ferroelastic post-stishovite transition.

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The recent observation of unusually high thermal conductivity exceeding 1000 W m K in single-crystal boron arsenide (BAs) has led to interest in the potential application of this semiconductor for thermal management. Although both the electron/hole high mobilities have been calculated for BAs, there is a lack of experimental investigation of its electronic properties. Here, a photoluminescence (PL) measurement of single-crystal BAs at different temperatures and pressures is reported.

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Two distinct stacking orders in ReS are identified without ambiguity and their influence on vibrational, optical properties and carrier dynamics are investigated. With atomic resolution scanning transmission electron microscopy (STEM), two stacking orders are determined as AA stacking with negligible displacement across layers, and AB stacking with about a one-unit cell displacement along the a axis. First-principles calculations confirm that these two stacking orders correspond to two local energy minima.

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The interior of the Earth is a high temperature and high pressure environment. High temperatures cause important changes in the physical and chemical properties of minerals. An increase in temperature leads to significant changes in the molecular and lattice vibrations, elasticity, and seismic velocity of minerals.

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