Synthesis and characterization of the crystal structure, the magnetic and the electrochemical properties of the new fluorophosphate LiNaFe[PO(4)]F

The new compound LiNaFe[PO(4)]F was synthesized by a solid state reaction route, and its crystal structure was determined using neutron powder diffraction data. LiNaFe[PO(4)]F was characterized by (57)Fe M?ssbauer spectroscopy, magnetic susceptibility, specific heat capacity, and electrochemical measurements. LiNaFe[PO(4)]F crystallizes with orthorhombic symmetry, space group Pnma, with a = 10.9568(6) ?, b = 6.3959(3) ?, c = 11.4400(7) ?, V = 801.7(1) ?(3) and Z = 8. The structure consists of edge-sharing FeO(4)F(2) octahedra forming FeFO(3) chains running along the b axis. These chains are interlinked by PO(4) tetrahedra forming a three-dimensional framework with the tunnels and the cavities filled by the well-ordered sodium and lithium atoms, respectively. The specific heat and magnetization measurements show that LiNaFe[PO(4)]F undergoes a three-dimensional antiferromagnetic ordering at T(N) = 20 K. The neutron powder diffraction measurements at 3 K show that each FeFO(3) chain along the b-direction is ferromagnetic (FM), while these FM chains are antiferromagnetically coupled along the a and c-directions with a non-collinear spin arrangement. The galvanometric cycling showed that without any optimization, one mole of alkali metal is extractable between 1.0 V and 5.0 V vs. Li(+)/Li with a discharge capacity between 135 and 145 mAh g(-1).     

Polynuclear and mixed-ligand mononuclear Cu(I) complexes with N-thiophosphorylated thioureas and 1,10-phenanthroline or PPh3

Deprotonation of the N-thiophosphorylated thioureas RC(S)NHP(S)(OiPr)(2) (R = Me(2)N, HL(I); iPrNH, HL(II); 2,6-Me(2)C(6)H(3)NH, HL(III), 2,4,6-Me(3)C(6)H(2)NH, HL(IV), aza-15-crown-5, HL(V)) and reaction with CuI or Cu(NO(3))(2) in aqueous EtOH leads to the polynuclear complexes [Cu(4)(L(I)-S,S')(4)], [Cu(8)(L(II)-S,S')(8)], and [Cu(3)(L(III-V)-S,S')(3)]. The structures of these compounds were investigated by IR, (1)H, (31)P{(1)H} NMR, UV-vis spectroscopy and elemental analyses. The crystal structures of [Cu(4)L(I)(4)], [Cu(8)L(II)(8)], [Cu(3)L(III,IV)(3)] were determined by single-crystal X-ray diffraction. Reaction of the deprotonated ligands (L(I-V))(-) with a mixture of CuI and 1,10-phenanthroline (phen) or PPh(3) leads to the mixed-ligand mononuclear complexes [Cu(phen)L(I-V)], [Cu(PPh(3))L(I-V)] or [Cu(PPh(3))(2)L(I-V)]. The same mixed-ligand complexes were obtained from the reaction of [Cu(4)L(I)(4)], [Cu(8)L(II)(8)], [Cu(3)L(III-V)(3)] with phen or PPh(3).     

Padé approximants to certain elliptic-type functions

Among all continua joining non-collinear points a ₁, a ₂, a ₃ ∈ ?, there exists a unique compact Δ ? ? that has minimal logarithmic capacity. For a complex-valued non-vanishing Dini-continuous function h on Δ, we define $${f_h}(z): = \frac{1}{{\pi i}}\int_\Delta {\frac{{h(t)}}{{t - z}}\frac{{dt}}{{{w^ + }(t)}}} $$ , where $w(z): = \sqrt {\prod\nolimits_{k = 0}^3 {(z - {a_k})} } $ and w ⁺ is the one-sided value according to some orientation of 1. In this work, we present strong asymptotics of diagonal Padé approximants to f _h and describe the behavior of the spurious pole and the regions of locally uniform convergence from a generic perspective.     

Extreme Value Theory for Hurwitz Complex Continued Fractions

The Hurwitz complex continued fraction is a generalization of the nearest integer continued fraction. In this paper, we prove various results concerning extremes of the modulus of Hurwitz complex continued fraction digits. This includes a Poisson law and an extreme value law. The results are based on cusp estimates of the invariant measure about which information is still limited. In the process, we obtained several results concerning the extremes of nearest integer continued fractions as well.     

Graphene supports the propagation of subwavelength optical solitons

Nonlinear propagation of light in a graphene monolayer is studied theoretically. It is shown how the large intrinsic nonlinearity of graphene at optical frequencies enables the formation of quasi one‐dimensional self‐guided beams (spatial solitons) featuring subwavelength widths at moderate electric‐field peak intensities. A novel class of nonlinear self‐confined modes resulting from the hybridization of surface plasmon polaritons with graphene optical solitons is also demonstrated.     

Assessing epithelial cell nuclear morphology by using azimuthal light scattering spectroscopy

We describe azimuthal light scattering spectroscopy (phi/LSS), a novel technique for assessing epithelial-cell nuclear morphology. The difference between the spectra measured at azimuthal angles phi = 0 degrees and phi = 90 degrees preferentially isolates the single backscattering contribution due to large (approximately 10 microm) structures such as epithelial cell nuclei by discriminating against scattering from smaller organelles and diffusive background. We demonstrate the feasibility of using phi/LSS for cancer detection by showing that spectra from cancerous colon tissue exhibit significantly greater azimuthal asymmetry than spectra from normal colonic tissues.     

Binding of single gold atoms on thin MgO(001) films

In the present Letter the first electron paramagnetic resonance spectra of single metal atoms on a single crystalline oxide surface are presented. For Au atoms on a MgO(001) film investigated here an analysis of the angular dependent resonance positions and the hyperfine coupling to (17)O shows that the atoms are bound on top of oxygen ions on the terrace of the film. This result is in perfect agreement with scanning tunneling microscopy measurements at 5 K presented here. The measured hyperfine matrix components allow an experimental verification of the theoretically proposed binding mechanism of Au atoms on MgO. In particular, the large reduction of the isotropic hyperfine coupling constant of supported Au as compared to free atoms is not due to a charge transfer at the interface but a hybridization of orbitals and a resulting polarization of the unpaired electron.     

Flavor- and CP-violating physics from new supersymmetric thresholds

Treating the minimal supersymmetric standard model as an effective theory, we study the implications of having dimension-five operators in the superpotential for flavor- and CP-violating processes, exploiting the linear decoupling of observable effects with respect to the new threshold scale c. We show that the assumption of weak-scale supersymmetry, when combined with the stringent limits on electric dipole moments and lepton-flavor-violating processes, provides sensitivity to Lambda as high as 10(7)-10(9) GeV (and up to 10(17) GeV through the theta term), while the next generation of experiments could directly probe the high-energy scales suggested by neutrino physics.     

Kinetic energy of free electrons affects MALDI positive ion yield via capture cross-section

A method for enhancing positive analyte ion signal in MALDI is described. The idea is based on influencing the kinetic energy of free electrons emitted from the organic/metal interface. It has been recently shown that free electrons in MALDI have energies around 1 eV. This energy is close to the maximum capture cross-section of most common MALDI matrices, leading to the efficient formation of negative matrix ions. This results in the reduction of the positive analyte ion yield. The effect can be minimized by shifting the kinetic energy of the electrons away from the maximum of the matrix capture cross-section by choosing a different substrate material.     

Yangians and Mickelsson Algebras I

We study the composition of the functor from the category of modules over the Lie algebra to the category of modules over the degenerate affine Hecke algebra of GL_N introduced by I. Cherednik, with the functor from the latter category to the category of modules over the Yangian due to V. Drinfeld. We propose a representation theoretic explanation of a link between the intertwining operators on the tensor products of -modules, and the "extremal cocycle" on the Weyl group of defined by D. Zhelobenko. We also establish a connection between the composition of the functors, and the "centralizer construction" of the Yangian discovered by G. Olshanski.