Hui-Sheng Wang

Eicosanuclear Cluster [Cu13W7] of Copper-Octacyanotungstate Bimetallic Assembly: Synthesis, Structure, and Magnetic Properties

Octacyanotungstate(V) reacts with Cu(NO(3))(2).2H(2)O and 1,4,7-trimethyl-1,4,7-triazacyclononane in methanol, resulting in an eicosanuclear cluster [Cu(13)W(7)], which shows a diamondoid shape with a Tolkowsky cut and bears intracluster ferromagnetic coupling.

Angular diffraction of an optical vortex induced by the Gouy phase

We investigate the diffraction of an optical vortex, when half of the beam is blocked by a knife edge. The Gouy phase is shown to influence the diffraction pattern strongly, in particular leading to the emergence of distorted and deformed diffraction fringes in the azimuthal direction. In analogy with single-slit diffraction, this phenomenon is analyzed in terms of angular diffraction within the azimuthal degree of freedom, by considering the uncertainty principle for the angular position and the angular momentum. Numerical simulations based on the fast-Fourier algorithm and the angular momentum expansion fit well with the experimental results.

Syntheses, structures, and magnetic properties of two kinds of unique heterometallic chains with mixed-bridging ligands of tricyanometalate and alkoxide.

The reactions of copper(II) salts, 1,3-bis(dimethylamino)-2-propanol (bdmapH) or 1,3-bis(amino)-2-propanol (bapH) and [(Tp)Fe(CN)(3)](-) (Tp = tris(pyrazolyl)hydroborate) gave four mixed-bridged heterometallic one-dimensional (1D) coordination polymers, {[(Tp)(2)Fe(2)(CN)(6)(OAc)(bdmap)Cu(2)(H(2)O)]·2H(2)O}(n) (1, HOAc = acetic acid), {[(Tp)(2)Fe(2)(CN)(6)(Pa)(bdmap)Cu(2)(H(2)O)]·2MeCN}(n) (2, HPa = propionic acid), {[(Tp)(2)Fe(2)(CN)(6)(Tfa)(bdmap)Cu(2)(H(2)O)]·2MeCN}(n) (3, HTfa = trifluoroacetic acid), and {[(Tp)(2)Fe(2)(CN)(6)(OAc)(bap)Cu(2)(MeOH)]·2MeOH·H(2)O}(n) (4). Complexes 1-3 show unique branched zigzag chain structures and complex 4 exhibits as a steplike chain. Ferromagnetic interactions between Fe(III) and Cu(II) ions by bridging cyanides are observed in all complexes. Strong antiferromagnetic interactions are presented between the Cu(II) ions in complexes 1-3, whereas similar antiferromagnetic coupling between Cu(II) ions is obviously weakened in complex 4 because of the distortion of penta-coordinated Cu(II) ions.

Enhanced optical angular momentum in cylinder waveguides with negative-index metamaterials

The optical angular momentum (AM) of helical electromagnetic (EM) modes in cylinder waveguides with negative-index metamaterials (NIM) is investigated. The AM density in NIM is shown to be negative valued with respect to the azimuthal mode index, in sharp contrast to that in regular dielectrics and vacuum. Furthermore, the AM flux per single-photon flux is found to be greatly enhanced in the NIM waveguides; its value depends on the form of EM momentum used in the AM. This interesting phenomenon is shown to be associated with the unique trapped EM modes in the NIM waveguides. Our investigation results could contribute to many potential applications, especially in realizing high density optical memory and buffers, and in solving the Abraham–Minkowski dilemma.

Comparative Study on Iterative-Optimization-Based Image Registration Algorithms

A detail comparative study is carried out on three representative iterative-optimization-based image registration methods, namely digital Image Correlation Using Newton-Raphson Iteration, Iterative Gray-Gradient Algorithm and Least Square Image Matching , which are originated and developed in the fields of optical experimental mechanics and stereo vision respectively. The mathematical consistency of the three algorithms is first demonstrated. Analysis and comparison of some further conclusions drawn from the three methods are then conducted. As the analysis and comparison show, these further conclusions can explain each other and can be mutually employed among the three methods. However, in view of algorithm implementation and extension, Image Correlation Using Newton-Raphson Iteration is more adaptable and flexible.