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241.
We propose a quantum secure direct communication protocol with entanglement swapping and hyperentanglement.Any two users, Alice and Bob, can communicate with each other in a quantum network, even though there is no direct quantum channel between them. The trust center, Trent, who provides a quantum channel to link them by performing entanglement swapping, cannot eavesdrop on their communication. This protocol provides a high channel capacity because it uses hyperentanglement, which can be generated using a beta barium borate crystal.  相似文献   
242.
A series of biocompatible and degradable hyperbranched polyether esters, poly(2‐hydroxyethyl 2‐methyloxirane‐2‐carboxylate) (pHEMOC) with controlled molecular weight (MW) and polydispersity (PD), have been synthesized via oxyanionic ring‐opening polymerization of HEMOC that was prepared by the epoxidation of 2‐hydroxyethyl methacrylate. pHEMOCs of their MWs ranging from about 500 to 20,000 with their PD values less than 1.5 are obtained simply by controlling 1,1,1‐tris‐hydroxymethylpropane initiator to HEMOC ratio. The pHEMOCs comprised of ether and ester backbones and multiple hydroxyl groups on the core and periphery results in materials that exhibit good degradability and low cytotoxicity, enabling them to be an ideal candidate material for biomedical applications. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 1643–1651  相似文献   
243.
We show that the lacunary maximal operator associated to a compact smooth hypersurface on which the Gaussian curvature nowhere vanishes to infinite order maps the standard Hardy space H 1 to L 1, . (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   
244.
The formation and properties of radial heteroepitaxial ZnO/(Mg,Zn)O nanowires is reported in which the (Mg,Zn)O is cubic. Synthesis is achieved via a catalyst-driven molecular beam epitaxy technique. The nanowires were grown on Ag-coated Si substrates at growth temperatures ranging from Tg=300 to 500 °C, using Zn, Mg, and O3/O2 as the reactive flux. Structural and compositional analyses indicate that the core of the nanowire is ZnO possessing the hexagonal wurtzite structure, with the (Mg,Zn)O sheath assuming the cubic rock salt structure. Since (Mg,Zn)O has a larger band-gap energy (up to 7.8 eV) than that of ZnO (3.37 eV), these radial heterostructure nanorods provide an interesting system for quantum confinement and one-dimensional nanoscale device studies. PACS 81.05.Dz; 81.07.Vb  相似文献   
245.
The thermal and electrical conductivity and mechanical properties of polyetherimide (PEI) containing either alkyl‐aminated (enGO) or phenyl‐aminated graphene (pnGO) oxides were studied. A solution casting method was used to prepare functionalized graphene oxide/PEI composites with different filler contents. The introduction of functionalized graphene oxide to the PEI matrix improved the thermal conductivity, electrical conductivity, and mechanical properties. The thermal conductivities of the enGO 3 wt%/PEI and pnGO 3 wt%/PEI composites were 0.324 W/mK and 0.329 W/mK, respectively, due to the high thermal conductivity of the graphene‐based materials and the strong interface adhesion due to the filler surface treatment between the fillers and the matrix. The electrical conductivities of the functionalized graphene oxide/PEI composites were larger than that of PEI, but the electrical conductivity values were generally low, which is consistent with the magnitude of the insulator. The strong interfacial adhesion between the fillers and the matrix led to improved mechanical properties. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   
246.
Prostate cancer is the most frequently diagnosed malignancy and the second leading cause of cancer mortality among men in the United States. Accumulating evidence suggests that lysophosphatidic acid (LPA) serves as an autocrine/paracrine mediator to affect initiation, progression and metastasis of prostate cancer. In the current study, we demonstrate that LPA stimulates migration and proliferation of highly metastatic human prostate cancer, PC-3M-luc-C6 cells. LPA-induced migration of PC-3M-luc-C6 cells was abrogated by pretreatment of PC-3M-luc-C6 cells with the LPA receptor 1/3 inhibitor Ki16425 or small interfering RNA (siRNA)-mediated silencing of endogenous LPA receptor 1, implicating a key role of the LPA-LPA receptor 1 signaling axis in migration of PC-3M-luc-C6 cells. In addition, LPA treatment resulted in augmented expression levels of Krüppel-like factor 4 (KLF4), and siRNA or short-hairpin RNA (shRNA)-mediated silencing of KLF4 expression resulted in the abolishment of LPA-stimulated migration and proliferation of PC-3M-luc-C6 cells. shRNA-mediated silencing of KLF4 expression resulted in the inhibition of in vivo growth of PC-3M-luc-C6 cells in a xenograft transplantation animal model. Taken together, these results suggest a key role of LPA-induced KLF4 expression in cell migration and proliferation of prostate cancer cells in vitro and in vivo.  相似文献   
247.
In this study, we report the design, synthesis and characterization of two new cationic iridium(III) complexes employing oxazole based ancillary ligand, namely, and [Ir(ppz)2(mbdiho)]PF6 (Complex 1) and [Ir(dfppy)2(mbdiho)]PF6 (Complex 2) and its use in light-emitting electrochemical cells (LECs). The design is based on 2-phenylpyrazole (ppz) and 2-(2,4-difluorophenyl)pyridine (dfppy) as cyclometalating ligands and 2,2-Methylenebis[3a,8a-dihydro-8H-indeno[1,2]oxazole] (mbdiho) as ancillary ligand. The effect of substituents in the cyclometalating ligands on the photophysical and electrochemical properties of the complexes has been investigated. The synthesized complexes were used for the fabrication of LEC devices and studied their electroluminescent properties. The complexes incorporated LECs resulted in a higher luminance of 2820 cd m?2 and current efficiency of 1.04 cd A?1 for Complex 2 than Complex 1. Our work suggests that the light emission of cationic iridium complexes can easily tuned by the substituents present on the cyclometalating ligands which resulted in yellow and green emission for LECs based on Complexes 1 and 2, respectively.  相似文献   
248.
We prepared sulfonated polyphosphazenes having various aryloxy substituents, and studied their thermal stabilities and membrane properties. Sulfonated polyphosphazenes were synthesized by the reaction of polydichlorophosphazene with sodium aryloxides and subsequent sulfonation with fuming sulfuric acid. With increasing the degree of sulfonation, the polymers showed higher proton conductivity, but suffered more from swelling in an aqueous solution. We introduced a hydroxymethylphenoxy group onto the phosphazene backbone as a self‐crosslinkable group by reaction of poly(dichlorophosphazene) and a sodium salt of 4‐hydroxymethylphenol. When a film of a sulfonated polymer having a methylol group was heated at 80 °C under vacuum for 1 h, it became insoluble in NMP, indicating the formation of a network structure. We investigated the crosslinking reaction of the polymers by DSC and FTIR. The crosslinking reaction proceeded only in the sulfonated polymers. Because the sulfonated polymers provide acidic protons, the methylol groups became more electrophilic and reacted with neighboring aromatic rings. A condensation reaction between themselves could also occur. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5850–5858, 2008  相似文献   
249.
250.
A series of Ge–Te–CuI far infrared transmitting chalcohalide glasses were prepared by traditional melt-quenching method and the glass-forming region was determined. Properties measurements include density, DTA, XRD, SEM, Vis–NIR and infrared (IR) transmission spectra. The results show that with the addition of CuI, the glass-forming ability is improved and nearly 30 mol% CuI can be dissolved into the Ge20Te80?x(CuI)x glass system. The density and glass transition temperature of Ge–Te–CuI chalcohalide glasses are within the range 5.459–5.960 g cm?3 and 150–184 °C, respectively. These glasses all have wide optical transmission window from 1.8 to 25 μm and offer an alternative solution for far infrared transmitting materials.  相似文献   
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