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Xinlong Wang

Publications and source records attributed to Xinlong Wang.

9 recordsLinked to original sources

Synthesis, characterization, and crystal structures of two novel high-nuclear nickel-substituted dimeric polyoxometalates.

Two novel high-nuclear Ni-substituted polyoxometalates Na9K[Ni7(OH)4(H2O)(CO3)2(HCO3)(A-alpha-SiW9O34)(beta-SiW10O37)].5H3O.18H2O (1) and K6Na4[{Ni6(H2O)4(mu2-H2O)4(mu3-OH)2}(x-SiW9O34)2].17.5H2O (2) have been obtained by reaction of K(8)[gamma-SiW10O36] with NiCl2.2H2O in basic conditions. Compounds 1 and 2 all represent the first polyoxometalates substituted by seven and six Ni centers, respectively. Also, compound 1 exhibits a novel asymmetric dimeric structure, composed of [A-alpha-SiW9O34]10- and [beta-SiW10O37]10- units linked by a Ni7 cluster and three carbonates, which exhibit tri- and bidentate coordination modes in 1.

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Acoustical diffraction tomography in a finite form based on the Rytov transform.

A new reconstruction algorithm in a finite form based on the Rytov transform is presented for acoustical diffraction tomography. Applying the Rytov transform to the governing differential wave equation necessarily introduces the so-called generalized scattering. Our analysis shows that the generalized scattered wave is asymptotically equivalent to the physically scattered wave, and also satisfies the Sommerfeld radiation condition in the far field. Using the method of formal parameter expansion, we further find that all other terms in the expansion of the object function vanish except the first- and second-order ones, and thus reach a finite form solution to the diffraction tomography. Our computer simulation confirms the effectiveness of the algorithm in the case of the scattering objects with cylindrical symmetry, also shows its limitations when it applies to the strong scattering.

Acoustics↗

Syntheses, structures, and photoluminescence of a novel class of d10 metal complexes constructed from pyridine-3,4-dicarboxylic acid with different coordination architectures.

Two novel d(10) metal coordination polymers [Zn(PDB)](n)() (1) and [Cd(3)(PDB)(2)(OH)(2)(H(2)O)(2)](n)() (2) (H(2)PDB = pyridine-3,4-dicarboxylic acid) have been synthesized under hydrothermal conditions and characterized by elemental analysis, IR, TG analysis, and single-crystal X-ray diffraction. Crystal data for 1: C(7)H(3)NO(4)Zn, orthorhombic Pna2(1), a = 8.423(17) A, b = 6.574(13) A, c = 12.899(3) A, Z = 4. Crystal data for 2: C(14)H(12)N(2)O(12)Cd(3), monoclinic C2/c, a= 20.130(4) A, b = 6.692(13) A, c = 13.081(3) A, beta = 102.78(3) degrees, Z = 4. Both compounds exhibit novel three-dimensional frameworks. Compound 1 not only possesses a one-dimensional rectangular channel but also contains infinite double-stranded helical chains. Compound 2 has two different types of channels, one being built up from pyridine rings and [CdO(5)N] and [CdO(6)] building units and the other being constructed from pyridine rings and [CdO(5)N] building units. Furthermore, both compounds show strong photoluminescence properties at room temperature.

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Hydrothermal synthesis and structure of a new helical chain constructed from only molybdenum-oxide building blocks.

The compound [NH(3)(CH(2))(2)NH(2)(CH(2))(2)NH(3)](2)[Mo(9)O(30)] was synthesized at 170 degrees C via hydrothermal techniques from the starting materials of Na(2)MoO(4).H(2)O, NH(2)(CH(2))(2)NH(CH(3))(2)NH(2), and H(2)O. The compound crystallizes in the space group C2/c of the monoclinic system with a = 21.308(4) A, b = 9.234(2) A, c = 19.195(4) A, beta = 120.27(3) degrees, V = 3261.9(11)A(3), Z = 4. Two novel and symmetrically related helices coexist in the centrosymmetric solid, in which the two kinds of helices appear in the left-handed and right-handed enantiomorphs, respectively. This is the first example of a helical chain structure consisting of only molybdenum-oxide building blocks. The central axis about each helical chain is a 2-fold screw axis.

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New vanadium phosphate ([(phen)VIVO]2(VV2O5)(HPO4))n with chiral layer architecture.

A new layered vanadium phosphate ([(phen)V(IV)O](2)(V(V)(2)O(5))(HPO(4))n has been hydrothermally synthesized and structurally characterized by elemental analysis, IR, and single-crystal X-ray diffraction. This compound crystallized in the monoclinic space group P2/c with a = 9.979(2) A, b = 9.886(2) A, c = 15.298(3) A, beta = 102.86(3) degrees, V = 1471.3(5) A(3), and Z = 4. In the structure of this compound, two nitrogen atoms of 1,10-phen are directly coordinated to the vanadium skeleton. Interestingly, the crystal structure consists of two types of chiral layers, one left-handed and the other right-handed, which lead to a racemic solid-state compound. In each layer, there coexist three distinct rings, described as a 8-membered ring [V(2)(oct)P(2)O(4)], 12-membered ring [V(2)(omicron)(ct)V(2)(tet)P(2)O(6)], and 16-membered ring [V(2)(omicron)(ct)V(4)(tet)P(2)O(8)].

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Layer-by-layer self-assembled ultrathin multilayer films of lanthanide polyoxometalates and poly(allylamine hydrochloride) and their photoluminescent properties.

Ultrathin multilayer films of two lanthanide polyoxometalates (LPOMs), K(17)[Eu(P(2)W(17)O(61))(2)] (EPW) and K(13)[Eu(SiW(11)O(39))(2)] (ESW), and poly(allylamine hydrochloride) (PAH) have been prepared by layer-by-layer self-assembly from dilute aqueous solutions. UV-vis spectroscopy and ellipsometry respectively show that the absorbance values at characteristic wavelengths and the thicknesses of the multilayer films increase linearly with the number of LPOM/PAH bilayers, suggesting that the deposition process is linear and highly reproducible from layer to layer. Average thicknesses of ca. 3.4 and 2.4 nm were determined for the EPW/PAH and ESW/PAH bilayers by ellipsometry, respectively. In addition, scanning electron microscopy (SEM) and atomic force microscopy (AFM) images provide the surface morphology of the LPOM/PAH films, indicating that the film surface is relatively uniform and smooth. The photoluminescent properties of these films have also been investigated by fluorescence spectroscopy. The LPOM/PAH multilayer film has a good thermal stability as shown by UV-vis, X-ray photoelectron, and fluorescence spectra.

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Ship recognition via its radiated sound: the fractal based approaches.

Due to the complexity of its radiated sound, ship recognition is difficult. Fractal approaches are proposed in this study, including fractal Brownian motion based analysis, fractal dimension analysis, and wavelet analysis, to augment existing feature extraction methods that are based on spectrum analysis. Experimental results show that fractal approaches are effective. When used to augment two traditional features, line and average spectra, fractal approaches led to better classification results. This implies that fractal approaches can capture some information not detected by traditional approaches alone.

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