Herein we report a rational design strategy for tailoring intermolecular interactions to enhance room‐temperature phosphorescence from purely organic materials in amorphous matrices at ambient conditions. The built‐...
详细信息
Herein we report a rational design strategy for tailoring intermolecular interactions to enhance room‐temperature phosphorescence from purely organic materials in amorphous matrices at ambient conditions. The built‐in strong halogen and hydrogen bonding between the newly developed phosphor G1 and the poly(vinyl alcohol) (PVA) matrix efficiently suppresses vibrational dissipation and thus enables bright room‐temperature phosphorescence (RTP) with quantum yields reaching 24 %. Furthermore, we found that modulation of the strength of halogen and hydrogen bonding in the G1–PVA system by water molecules produced unique reversible phosphorescence‐to‐fluorescence switching behavior. This unique system can be utilized as a ratiometric water sensor.
Graphene,as a typical two-dimensional layered material,possesses extraordinary electronic and optical properties that render it for a wide range of potential applications including biomedicine[1].Inspired by the graph...
详细信息
Graphene,as a typical two-dimensional layered material,possesses extraordinary electronic and optical properties that render it for a wide range of potential applications including biomedicine[1].Inspired by the graphene research and development,graphene-like two-dimensional materials(2DMats)also show application potentials in biomedicine due to their unique properties[2-4].However,environmental and biological infuences of these 2DMats remain to be *** we reported the antibacterial activity of two-dimensional(2D)chemically exfoliated MoS2(ce-MoS2)sheets[5].We found that the antibacterial activity of ce-MoS2 sheets was much more potent than that of the raw MoS2 powders used for the synthesis of ce-MoS2 sheets possibly due to the 2D planar structure(high specifc surface area)and higher conductivity of the *** investigated the antibacterial mechanisms of the ce-MoS2 sheets and proposed their antibacterial *** found that the ce-MoS2 sheets could produce reactive oxygen species(ROS),different from previous report on graphenebased ***,the oxidation capacity of the ce-MoS2 sheets toward glutathione oxidation showed a time and concentration dependent trend,which is fully consistent with the antibacterial behaviour of the ce-MoS2 *** results suggest that antimicrobial behaviors were attributable to both membrane and oxidation *** antibacterial pathways include MoS2-bacteria contact induced membrane stress,superoxide anion(O2·–)induced ROS production by the ce-MoS2,and the ensuing superoxide anion-independent *** study thus indicates that the tailoring of dimension of nanomaterials and their electronic properties would manipulate antibacterial activity.
Measurements of thermoelectric power S(T) on the Kondo disorder system CePt4Ge12−xSbx are remarkably sensitive to the distribution of Kondo temperatures P(TK), which develops out of a single Kondo temperature TK in Ce...
详细信息
Measurements of thermoelectric power S(T) on the Kondo disorder system CePt4Ge12−xSbx are remarkably sensitive to the distribution of Kondo temperatures P(TK), which develops out of a single Kondo temperature TK in CePt4Ge12 and is governed by the degree to which hybridization is disordered. Three distinct S(T) behaviors are observed in concentration regions which coincide with the boundaries of Fermi-liquid, non-Fermi-liquid, and antiferromagnetically ordered ground states in this system. In the non-Fermi-liquid region, S(T)/T diverges logarithmically with decreasing temperature over nearly one decade in the case of x=0.84.
We present the effect of yttrium substitution on superconductivity in the La1−xYxO0.5F0.5BiS2 system. Polycrystalline samples with nominal Y concentrations up to 40% were synthesized and characterized via electrical r...
详细信息
We present the effect of yttrium substitution on superconductivity in the La1−xYxO0.5F0.5BiS2 system. Polycrystalline samples with nominal Y concentrations up to 40% were synthesized and characterized via electrical resistivity, magnetic susceptibility, and specific-heat measurements. Y substitution reduces the lattice parameter a and unit-cell volume V, and a correlation between the lattice parameter c, the La-O-La bond angle, and the superconducting critical temperature Tc is observed. The chemical pressure induced by Y substitution for La produces neither the high-Tc superconducting phase nor the structural phase transition seen in LaO0.5F0.5BiS2 under externally applied pressure.
We describe dipolar nematic colloids comprising mutually bound solid microspheres, three-dimensional skyrmions, and point defects in a molecular alignment field of chiral nematic liquid crystals. Nonlinear optical ima...
详细信息
We describe dipolar nematic colloids comprising mutually bound solid microspheres, three-dimensional skyrmions, and point defects in a molecular alignment field of chiral nematic liquid crystals. Nonlinear optical imaging and numerical modeling based on minimization of Landau–de Gennes free energy reveal that the particle-induced skyrmions resemble torons and hopfions, while matching surface boundary conditions at the interfaces of liquid crystal and colloidal spheres. Laser tweezers and videomicroscopy reveal that the skyrmion-colloidal hybrids exhibit purely repulsive elastic pair interactions in the case of parallel dipoles and an unexpected reversal of interaction forces from repulsive to attractive as the center-to-center distance decreases for antiparallel dipoles. The ensuing elastic self-assembly gives rise to colloidal chains of antiparallel dipoles with particles entangled by skyrmions.
We apply ultrafast x-ray diffraction with femtosecond temporal resolution to monitor the lattice dynamics in a thin film of multiferroic BiFeO3 after above-band-gap photoexcitation. The sound-velocity limited evolutio...
详细信息
We apply ultrafast x-ray diffraction with femtosecond temporal resolution to monitor the lattice dynamics in a thin film of multiferroic BiFeO3 after above-band-gap photoexcitation. The sound-velocity limited evolution of the observed lattice strains indicates a quasi-instantaneous photoinduced stress which decays on a nanosecond time scale. This stress exhibits an inhomogeneous spatial profile evidenced by the broadening of the Bragg peak. These new data require substantial modification of existing models of photogenerated stresses in BiFeO3: the relevant excited charge carriers must remain localized to be consistent with the data.
We review recent analyses of the various aspects related to the performance of core/shell nanocatalyst particles used as electrodes in proton exchange membrane fuel cells. These nanoparticles usually consist of a thin...
详细信息
A new metal complex [MnL2]（NO3）***3CN （1） was synthesized by reaction of 4＇-4-（],2,4-triazol-]-yl）- phenyl-2,2＇：6＇,2＂-terpyridine （L） with manganese nitrate. The structure of the complex was determined by...
详细信息
A new metal complex [MnL2]（NO3）***3CN （1） was synthesized by reaction of 4＇-4-（],2,4-triazol-]-yl）- phenyl-2,2＇：6＇,2＂-terpyridine （L） with manganese nitrate. The structure of the complex was determined by X-ray crystallography. The results of UV-vis studies showed that the complex exhibits colorimetric sensing ability for Fe3~, which can be observed by naked eye.
The resistivity of vanadium dioxide (VO2) decreased by over one order of magnitude upon localized illumination with x rays at room temperature. Despite this reduction, the structure remained in the monoclinic phase an...
详细信息
The resistivity of vanadium dioxide (VO2) decreased by over one order of magnitude upon localized illumination with x rays at room temperature. Despite this reduction, the structure remained in the monoclinic phase and had no signature of the high-temperature tetragonal phase that is usually associated with the lower resistance. Once illumination ceased, relaxation to the insulating state took tens of hours near room temperature. However, a full recovery of the insulating state was achieved within minutes by thermal cycling. We show that this behavior is consistent with random local-potential fluctuations and random distribution of discrete recombination sites used to model residual photoconductivity.
暂无评论