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981.
International Journal of Theoretical Physics - We propose the scheme for cyclic controlled symmetry quantum teleportation by using one three-dimensional hyper-entangled state as the quantum...  相似文献   
982.
Copper nanoclusters (CuNCs) as a new class of fluorescent materials have attracted a great deal of interest due to their outstanding fluorescence properties. In this work, a variety of organic solvents were used to induce self-assembly of glutathione-capped CuNCs (GSH-CuNCs) to form ordered assemblies with enhanced fluorescence properties. Assemblies with multicolor fluorescence emission were constructed on the basis of the aggregation-induced emission (AIE) of GSH-CuNCs and the solvent effect. The fluorescence emission from these GSH-CuNCs assemblies can also be tuned from yellow to purple by changing the organic solvent. A possible mechanism based on the size of the assemblies and electron transfer was explored to explain the solvent effects on GSH-CuNCs. Stimuli-responsive nanoswitches with excellent reversibility can be controlled by changing the type of organic solvent and the ratio of the organic solvent to the aqueous solution of GSH-CuNCs. As the CuNCs assemblies exhibit strong, stable, and color-tunable fluorescence, they were employed as color-conversion materials for recognizing different organic solvents.  相似文献   
983.
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986.
Cucurbit[7]uril (CB[7]) is known to bind strongly to hydrophilic amino saccharide guests with exceptional α‐anomer selectivities under aqueous conditions. Single‐crystal X‐ray crystallography and computational methods were used to elucidate the reason behind this interesting phenomenon. The crystal structures of protonated galactosamine (GalN) and glucosamine (GluN) complexes confirm the inclusion of α anomers inside CB[7] and disclose the details of the host–guest binding. Whereas computed gas‐phase structures agree with these crystal structures, gas‐phase binding free energies show preferences for the β‐anomer complexes over their α counterparts, in striking contrast to the experimental results under aqueous conditions. However, when the solvation effect is considered, the binding structures drastically change and the preference for the α anomers is recovered. The α anomers also tend to bind more tightly and leave less space in the CB[7] cavity toward inclusion of only one water molecule, whereas loosely bound β anomers leave more space toward accommodating two water molecules, with markedly different hydrogen‐bonding natures. Surprisingly, entropy seems to contribute significantly to both anomeric discrimination and binding. This suggests that of all the driving factors for the strong complexation of the hydrophilic amino saccharide guests, water mediation plays a crucial role in the anomer discrimination.  相似文献   
987.
The objective of this study was to assess the cytotoxicity of water-dispersible CuO nanoparticles by quantifying the reactive oxygen species (ROS)-related genes (glutathione S-transferase (GST) and catalase) using real-time polymerase chain reaction (RT-PCR). Monodisperse CuO nanoparticles of 14 nm in size were used. Cytotoxicity of CuO nanoparticles was evaluated under in vitro condition at different concentrations (10, 50, and 100 μg/ml) and incubation times (12, 24, and 48 h) with human cancer cell lines (breast cancer epithelial cells). The genetic level cytotoxic screening produced consistent results showing that GST and catalase ROS gene expression was maximized in 24 h incubation at 100 μg/ml concentration of CuO nanoparticles. However, the cytotoxicity of water-dispersible CuO nanoparticle was not significant compared with control experiments, demonstrating its high potential in the application of nanomedicines for a diagnostic and therapeutic tool.  相似文献   
988.
989.
Water-soluble triplet sensitizer with permethyl-β-cyclodextrin(PMCD) grafting on a Schiff-base Pt(Ⅱ)complex(Pt-2),in which PMCD unit serves as a host for binding the acceptors and the Schiff-base Pt(Ⅱ)complex serves as a triplet sensitizer,was synthesized to investigate the effect of supramolecular complexation and assembly on the triplet-triplet annihilation upconversion emission in water.9,10-Diphenylanthracence(DPA) carboxylate(A-1) and its dimer(A-2) in which two DPA carboxylate were covalently linked with an alkyl chain were synthesized as triplet acceptors which also play a role of guest molecules for PMCD.A-1 and A-2 showed high affinity with PMCD,and A-2 can readily aggregate in water and form micron sized assemblies due to the hydrophobic effect and π-π stacking of anthracene core in A-2.The efficiency of TTA-UC was demonstrated to be enhanced by a synergistic effect of host-guest complexation of Pt-2 with A-2 and the self-aggregation of the acceptor A-2,which facilitated the energy transfer and energy fusion among donor and acceptor.  相似文献   
990.
A facile, scalable route to new nanocomposites that are based on carbon nanotubes/heteroatom‐doped carbon (CNT/HDC) core–sheath nanostructures is reported. These nanostructures were prepared by the adsorption of heteroatom‐containing ionic liquids on the walls of CNTs, followed by carbonization. The design of the CNT/HDC composite allows for combining the electrical conductivity of the CNTs with the catalytic activity of the heteroatom‐containing HDC sheath layers. The CNT/HDC nanostructures are highly active electrocatalysts for the oxygen reduction reaction and displayed one of the best performances among heteroatom‐doped nanocarbon catalysts in terms of half‐wave potential and kinetic current density. The four‐electron selectivity and the exchange current density of the CNT/HDC nanostructures are comparable with those of a Pt/C catalyst, and the CNT/HDC composites were superior to Pt/C in terms of long‐term durability and poison tolerance. Furthermore, an alkaline fuel cell that employs a CNT/HDC nanostructure as the cathode catalyst shows very high current and power densities, which sheds light on the practical applicability of these new nanocomposites.  相似文献   
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