12,227 research outputs found

    Triplet luminescent dinuclear-gold(I) complex-based light-emitting diodes with low turn-on voltage

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    The electroluminescence (EL) from a dinuclear-gold(I)-chlorate compound containing bridging phosphine ligands [Au 2(dppm)Cl 2] as emitting layer is reported. Devices with a structure Al/Au 2(dppm)Cl 2/indium-tin-oxide demonstrated a uniform emission under the driving voltage below 1 V. The EL emission was from triplet excited state and the emission color of the device was found to depend on the deposition rate of Au 2(dppm)Cl 2, which can be explained as the different aggregation forms of the stacking compound in the deposition process. © 1999 American Institute of Physics.published_or_final_versio

    Detecting Extra Dimension by Helium-like Ions

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    Considering that gravitational force might deviate from Newton's inverse-square law and become much stronger in small scale, we present a method to detect the possible existence of extra dimensions in the ADD model. By making use of an effective variational wave function, we obtain the nonrelativistic ground energy of a helium atom and its isoelectronic sequence. Based on these results, we calculate gravity correction of the ADD model. Our calculation may provide a rough estimation about the magnitude of the corresponding frequencies which could be measured in later experiments.Comment: 8 pages, no figures, accepted by Mod. Phys. Lett.

    Variation of small strain stiffness for piping-influenced Toyoura sand

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    Landslides triggered by piping are frequently reported during stormy periods. Despite large amount of model tests related with internal erosion, there is little research on the mechanical properties of disturbed soil by means of element experiment. In this paper, an attempt was made to create artificial piping by dissolving water soluble material (glucose) in sand. Chains of voids were generated when water was infiltrated and drained out through the specimen. Small torsional cyclic loadings were conducted on the hollow cylindrical specimens in order to obtain the small strain stiffness of the soil before/after piping erosion. According to the results, reduction of shear modulus was found in specimen with internal pipes after water infiltration, and piping-induced anisotropy was found to be obvious

    Quantum broadcast communication

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    Broadcast encryption allows the sender to securely distribute his/her secret to a dynamically changing group of users over a broadcast channel. In this paper, we just consider a simple broadcast communication task in quantum scenario, which the central party broadcasts his secret to multi-receiver via quantum channel. We present three quantum broadcast communication schemes. The first scheme utilizes entanglement swapping and Greenberger-Horne-Zeilinger state to realize a task that the central party broadcasts his secret to a group of receivers who share a group key with him. In the second scheme, based on dense coding, the central party broadcasts the secret to multi-receiver who share each of their authentication key with him. The third scheme is a quantum broadcast communication scheme with quantum encryption, which the central party can broadcast the secret to any subset of the legal receivers

    Acoustic cues to tonal contrasts in Mandarin: Implications for cochlear implants

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    The present study systematically manipulated three acoustic cues-fundamental frequency (f0), amplitude envelope, and duration-to investigate their contributions to tonal contrasts in Mandarin. Simplified stimuli with all possible combinations of these three cues were presented for identification to eight normal-hearing listeners, all native speakers of Mandarin from Taiwan. The f0 information was conveyed either by an f0-controlled sawtooth carrier or a modulated noise so as to compare the performance achievable by a clear indication of voice f0 and what is possible with purely temporal coding of f0. Tone recognition performance with explicit f0 was much better than that with any combination of other acoustic cues (consistently greater than 90% correct compared to 33%-65%; chance is 25%). In the absence of explicit f0, the temporal coding of f0 and amplitude envelope both contributed somewhat to tone recognition, while duration had only a marginal effect. Performance based on these secondary cues varied greatly across listeners. These results explain the relatively poor perception of tone in cochlear implant users, given that cochlear implants currently provide only weak cues to f0, so that users must rely upon the purely temporal (and secondary) features for the perception of tone. (c) 2008 Acoustical Society of America

    Study on Decays of DsJ∗(2317)D_{sJ}^{*}(2317) and DsJ(2460)D_{sJ}(2460) in terms of the CQM Model

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    Based on the assumption that DsJ∗(2317)D_{sJ}^{*}(2317) and DsJ(2460)D_{sJ}(2460) are the (0+,1+)(0^+, 1^+) chiral partners of DsD_{s} and Ds∗D^*_s, we evaluate the strong pionic and radiative decays of DsJ∗(2317)D_{sJ}^{*}(2317) and DsJ(2460)D_{sJ}(2460) in the Constituent Quark Meson (CQM) model. Our numerical results of the relative ratios of the decay widths are reasonably consistent with data.Comment: 12 pages, 2 figures, 4 tables, a few references adde

    Nucleotide-binding oligomerization domain-containing protein 2 (Nod2) modulates T1DM susceptibility by gut microbiota

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    Nucleotide-binding oligomerization domain-containing protein 2 (Nod2) is an innate immune receptor. To investigate the role of Nod2 in susceptibility to the autoimmune disease, type 1 diabetes mellitus (T1DM), we generated Nod2-/- non-obese diabetic (NOD) mice. The Nod2-/-NOD mice had different composition of the gut microbiota compared to Nod2+/+NOD mice and were significantly protected from diabetes, but only when housed separately from Nod2+/+NOD mice. This suggested that T1DM susceptibility in Nod2-/-NOD mice is dependent on the alteration of gut microbiota, which modulated the frequency and function of IgA-secreting B-cells and IL-10 promoting T-regulatory cells. Finally, colonizing germ-free NOD mice with Nod2-/-NOD gut microbiota significantly reduced pro-inflammatory cytokine-secreting immune cells but increased T-regulatory cells. Thus, gut microbiota modulate the immune system and T1D susceptibility. Importantly, our study raises a critical question about the housing mode in the interpretation of the disease phenotype of genetically-modified mouse strains in T1DM studies
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