Tunneling of two-dimensional surface polaritons through nanogaps in atomically thin crystals

We theoretically investigate the tunneling of two-dimensional surface polaritons (2DSPs) through nanometer-wide gaps in atomically thin crystals. For quantitatively accurate results, we developed a rigorous model based on the diffraction of 2DSPs for strongly confined surface polaritons (i.e., the polariton wavelength much shorter than the free-pace photon wavelength). We find distinctive features of the tunneling of 2DSPs. First, radiation loss during the tunneling is shown to be negligible. Second, the reflection coefficient R and tunneling coefficient T are shown to exhibit an anomalous logarithm singularity in their dependency on the gap width. Even for a gap size over two orders of magnitude smaller than the surface polariton wavelength, an appreciable reflection coefficient was observed in our calculation. Finally, we show that when the gap size increases, the phase of R saturates very rapidly to a nontrivial value of π/4. Based on these results, we further examine resonant tunneling of 2DSP through two identical gaps separated by a distance L, and establish a resonance condition defined by L≈λsp(4n-1)/8 with a positive integer n

Protein expression and purification of integrin I domains and IgSF ligands for crystallography

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Magnetotransport and dielectric properties of perovskite ruthenate and titanate thin films

2007-2008 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Benefits of current percolation in superconducting coated conductors

The critical currents of MOD/RABiTS and PLD/IBAD coated conductors have been measured as a function of magnetic field orientation and compared to films grown on single crystal substrates. By varying the orientation of magnetic field applied in the plane of the film, we are able to determine the extent to which current flow in each type of conductor is percolative. Standard MOD/RABiTS conductors have also been compared to samples whose grain boundaries have been doped by diffusing Ca from an overlayer. We find that undoped MOD/RABiTS tapes have a less anisotropic in-plane field dependence than PLD/IBAD tapes and that the uniformity of critical current as a function of in-plane field angle is greater for MOD/RABiTS samples doped with Ca.EPSRC US Department of Energ

Enabling Thin and Flexible Solid-State Composite Electrolytes by the Scalable Solution Process

All solid-state batteries (ASSBs) have the potential to deliver higher energy densities, wider operating temperature range, and improved safety compared with today's liquid-electrolyte-based batteries. However, of the various solid-state electrolyte (SSE) classes - polymers, sulfides, or oxides - none alone can deliver the combined properties of ionic conductivity, mechanical, and chemical stability needed to address scalability and commercialization challenges. While promising strategies to overcome these include the use of polymer/oxide or sulfide composites, there is still a lack of fundamental understanding between different SSE-polymer-solvent systems and its selection criteria. Here, we isolate various SSE-polymer-solvent systems and study their molecular level interactions by combining various characterization tools. With these findings, we introduce a suitable Li7P3S11SSE-SEBS polymer-xylene solvent combination that significantly reduces SSE thickness (∼50 μm). The SSE-polymer composite displays high room temperature conductivity (0.7 mS cm-1) and good stability with lithium metal by plating and stripping over 2000 h at 1.1 mAh cm-2. This study suggests the importance of understanding fundamental SSE-polymer-solvent interactions and provides a design strategy for scalable production of ASSBs

湖北省罗田凤凰关混合岩浅色体的类型及其锆石U-Pb年龄

Based on the principle of refolding transecting and overprinting, and eliminating the refolding pseudomorph resulting from the effect of viscous folds, 8-generation leucosomes have been distinguished in the Fenghuangguan migmatites in Luotian, Hubei Province, central China. The results of the major-, trace- and rare earth-element geochemistry indicate that the leucosome for dating the U-Pb age was derived from anatexis. The zircon U-Pb age suggests that there was a migmatization during the Yanshan Period, which may represent an important anatex is at the age, (129. 3 +/- 0. 8) Ma.根据混合岩浅色体的重褶、横切和叠加关系并剔除因粘性褶皱效应引起的重褶皱假象, 在湖北罗田凤凰关识别出8 个世代的浅色体。它们的主量、微量和稀土元素地球化学研究表明, 用于锆石U-Pb 定年的浅色体是深熔成因的。锆石U-Pb 定年结果表明, 在大别杂岩内存在燕山期的混合岩化作用, 其时代为（１２９．３．８）Ｍａ。published_or_final_versio

The potential roles of hepatocyte growth factor (HGF)-MET pathway inhibitors in cancer treatment

MET is located on chromosome 7q31 and is a proto-oncogene that encodes for hepa-tocyte growth factor (HGF) receptor, a member of the receptor tyrosine kinase (RTK) family. HGF, also known as scatter factor (SF), is the only known ligand for MET. MET is a master regulator of cell growth and division (mitogenesis), mobility (motogenesis), and differentiation (morphogenesis); it plays an important role in normal development and tissue regeneration. The HGF-MET axis is frequently dysregulated in cancer by MET gene amplification, translocation, and mutation, or by MET or HGF protein overexpression. MET dysregulation is associated with an increased propensity for metastatic disease and poor overall prognosis across multiple tumor types. Targeting the dysregulated HGF-MET pathway is an area of active research; a number of monoclonal antibodies to HGF and MET, as well as small molecule inhibitors of MET, are under development. This review summarizes the key biological features of the HGF-MET axis, its dysregulation in cancer, and the therapeutic agents targeting the HGF-MET axis, which are in development. © 2014 Parikh et al

Neoproterozoic Mafic-Ultramafic Intrusions from the Fanjingshan Region, South China: Implications for Subduction-Related Magmatism in the Jiangnan Fold Belt

published_or_final_versio

Regression with Linear Factored Functions

Many applications that use empirically estimated functions face a curse of dimensionality, because the integrals over most function classes must be approximated by sampling. This paper introduces a novel regression-algorithm that learns linear factored functions (LFF). This class of functions has structural properties that allow to analytically solve certain integrals and to calculate point-wise products. Applications like belief propagation and reinforcement learning can exploit these properties to break the curse and speed up computation. We derive a regularized greedy optimization scheme, that learns factored basis functions during training. The novel regression algorithm performs competitively to Gaussian processes on benchmark tasks, and the learned LFF functions are with 4-9 factored basis functions on average very compact.Comment: Under review as conference paper at ECML/PKDD 201

Evolution of superconductivity in K2-xFe4+ySe5: Spectroscopic studies of X-ray absorption and emission.

This study investigates the evolution of superconductivity in K2-xFe4+ySe5 using temperature-dependent X-ray absorption and resonant inelastic X-ray scattering techniques. Magnetization measurements show that polycrystalline superconducting (SC) K1.9Fe4.2Se5 has a critical temperature (T c) of ∼31 K with a varying superconducting volume fraction, which strongly depends on its synthesis temperature. An increase in Fe-structural/vacancy disorder in SC samples with more Fe atoms occupying vacant 4d sites is found to be closely related to the decrease in the spin magnetic moment of Fe. Moreover, the nearest-neighbor Fe-Se bond length in SC samples exceeds that in the non-SC (NS) sample, K2Fe4Se5, which indicates a weaker hybridization between the Fe 3d and Se 4p states in SC samples. These results clearly demonstrate the correlations among the local electronic and atomic structures and the magnetic properties of K2-xFe4+ySe5 superconductors, providing deeper insight into the electron pairing mechanisms of superconductivity