Frequency-upconverted organic crystal

The fluorescent characteristics of Troger's base have been investigated experimentally. A one-photon-induced fluorescent spectrum was observed, and the peak wavelength was at 337 nm with a full width at half-maximum of ~85nm . The violet radiation of the Troger's base crystal could result from the pi(*) -pi transition of the benzenoid pi bond. Two-photon-pumped frequency-upconverted fluorescence was obtained, which is a wideband emission with the main peak wavelength at 337 nm and a subordinate peak. Donor groups and acceptor groups of electrons in the aromatic rings strengthen the two-photon-pumped frequency-upconverted fluorescence.     

Enhanced infrared transmission through subwavelength coaxial metallic arrays

We report the observation of enhanced near-infrared transmission through arrays of subwavelength coaxial metallic structures compared with that through comparable diameter hole arrays as a result of localized electromagnetic modes supported by the complex coaxial unit cell. Polarization and angle-dependent transmission measurements clearly demonstrate the coupling between this localized mode and delocalized surface plasmon modes. A generalized, multiple discrete states Fano line shape provides a good fit to the experimental results.     

Dirichlet inhomogeneous boundary value problem for the n+1 complex Ginzburg-Landau equation

We study the following complex Ginzburg-Landau equation with cubic nonlinearity on for under initial and Dirichlet boundary conditions u(x,0)=h(x) for x∈Ω, u(x,t)=Q(x,t) on ∂Ω where h,Q are given smooth functions. Under suitable conditions, we prove the existence of a global solution in H¹. Further, this solution approaches to the solution of the NLS limit under identical initial and boundary data as a,b→0⁺.     

Tetrahedral chalcogenide clusters and open frameworks

By integrating porosity with electrical or optical properties, microporous chalcogenides may have unique applications. Here we review recent advances and discuss concepts in the synthesis and crystal structure of tetrahedral clusters and their frameworks. These chalcogenides can be viewed as trivalent metal chalcogenides doped with tetra-, di-, or monovalent metal cations. Low-valent cations help to increase the cluster size, while high-valent cations have the opposite effect.     

Polyoxometalates matrixed into surfactants: synthesis, characterizations, and conformations of surfactants

We synthesized two surfactant-encapsulated polyoxometalate (POM) clusters (SECs), (DODA)(15)[H(3)Mo(57)V(6)(NO)(6)O(189)(H(2)O)(12)(VO)(6)].13H(2)O (SEC-2, DODA: dimethyldioctadecyl ammonium) and (DODA)(12)[Eu(H(2)O)P(5)W(30)O(110)].28H(2)O (SEC-3). SECs were characterized in detail by elemental analysis, UV-Vis absorption spectroscopy, FTIR, 1H NMR, thermogravimetric analysis, Langmuir isotherms, and powdered X-ray diffractions. SEC-2 can form a stable monolayer at the air-water interface. SEC-2 and SEC-3 possess a layered structure with periodicities of 3.8 and 5.05 nm, respectively. Alkyl chains in SEC-2 are disordered, but SEC-3 is indicative of well-ordered alkyl chains. According to the simplified structural analysis for SEC-2 and SEC-3, DODAs occupy areas of 1.12 and 0.589 nm(2) on the surface of the POMs, which are characteristic of the liquid-like and crystalline-like phases for DODA, respectively. The different conformations of DODAs then lead to the different packing structures of SECs. This work is aiming to control the organizational structures of the POM-based materials by selecting the appropriate POMs.     

Electrochemical investigations of baicalin and DNA–baicalin interactions

Baicalin is an anti-HIV drug purified from the traditional Chinese medicinal plant Scutellaria Baicalensis Georgi. Baicalin has proven to be electroactive at pyrolytic graphite (PG) electrodes. We thus studied its interaction with DNA via the electrochemical approach. We observed that the peak currents corresponding to the baicalin reduction–oxidation (redox) reaction significantly decrease upon the addition of DNA. With complementary ultraviolet/visible (UV/Vis) spectroscopic evidence, we suggest that baicalin binds to DNA through intercalation. This feature has enabled baicalin to discriminate between double-stranded DNA (dsDNA) and single-stranded DNA (ssDNA).Electronic Supplementary Material Supplementary material is available in the online version of this article at . A link in the frame on the left on that page takes you directly to the supplementary material.     

多圆柱上的完全准凸映射

在C~n中有界凸Reinhardt域上讨论了一类介于凸映射类与星形映射类之间的“完全准凸映射类”.特别地,在C~n中的多圆柱上给出了完全准凸映射的分解定理,得到了多圆柱上判别凸映射的一个改进的充分条件.     

Fano versus Kondo resonances in a multilevel "semiopen" quantum dot

Linear conductance across a large quantum dot via a single level epsilon(0) with large hybridization to the contacts is strongly sensitive to quasibound states localized in the dot and weakly coupled to epsilon(0). The conductance oscillates with the gate voltage due to interference of the Fano type. At low temperature and Coulomb blockade, Kondo correlations damp the oscillations on an extended range of gate voltage values, by freezing the occupancy of the epsilon(0) level itself. As a consequence, the antiresonances of Fano origin are washed out. The results are in good correspondence with experimental data for a large quantum dot in the semiopen regime.