The analysis of 10 normal and 51 mitral valve pathology making a total of 61 heart sound signals that were obtained with Littmann 4100 Digital Stethoscope were conducted in this study. Following the recorded sound signals were denoised by using wavelet filters, the signals were applied bicoherence analysis that is an high order spectral analysis method. It has been demonstrated that varieties of mitral valve pathology could be determined by three-dimensional surfaces of bicoherence and maximum bicoherence values. 相似文献
New lead(II)‐saccharin complexes, [Pb(sac)2(pym)] (1) and [Pb(sac)2(pydm)] (2) (sac = saccharinate anion; pym = 2‐pyridylmethanol; pydm = pyridine‐2, 6‐dimethanol) were synthesized and characterized by IR spectroscopy and single crystal X‐ray diffractometry. Complex 1 crystallizes in the monoclinic P21/c space group with Z = 4, while the crystals of complex 2 are extremely X‐ray sensitive and decompose by the X‐ray beam within one day. Pym and pydm act as bi‐ and tridentate ligands, respectively. Most important feature of the complexes is non‐equivalent coordination of the sac ligands to the lead(II) atom. In the complex 1 , the sac ligands coordinate to the lead(II) ion in two distinct manners. One sac ligand behaves as a bridge between the lead(II) atoms through its N and carbonyl O atoms, whereas the other sac ligand acts as a bidentate chelating ligand through its N and carbonyl O atoms which is bicoordinating and also bridges the metal atoms to achieve the seven‐coordination. The structure is built up of three‐dimensional chains formed by the bridging of the PbN3O2 units and also held intermolecular hydrogen bonds. The IR spectra of the complexes were discussed in detail. 相似文献
The reaction of sodium benzoxasulfamate (nbs) with cadmium(II) and mercury(II) sulfate in aqueous solution yield the novel complexes [Cd(nbs)2(H2O)4] (1) and [Hg(nbs)2(H2O)3] ( 2 ), respectively. The complexes were characterized by elemental analyses, IR spectroscopy and X‐ray crystallography. Complex 1 is monomeric and has an octahedral arrangement in which the N‐donor nbs ligands occupy the axial positions, while the water oxygen atoms form the equatorial plane. Complex 2 is polymeric and shows a pentagonal bipyramidal arrangement achieved by the bridging of the HgN2O3 units through the weak interaction of the O atoms of the nitro group. The nbs ligands also occupy the axial positions of the pentagonal bipyramid, whereas three water and two nitro oxygen atoms constitute the pentagonal plane. The crystal structure packing in both crystals is achieved by the intermolecular hydrogen bonds involving water hydrogen atoms, nitro and sulfonyl oxygen atoms. 相似文献
The title compound, C6H8NO+·H2PO4−, consists of 2‐(hydroxymethyl)pyridinium and dihydrogenphosphate ions. The dihydrogenphosphate moieties are linked into chains by pairs of P—O—H⃛O—P hydrogen bonds. The 2‐(hydroxymethyl)pyridinium cations are connected to the dihydrogenphosphate units by O—H⃛O and N—H⃛O hydrogen bonds. Weak π–π interactions help to determine the interchain packing. 相似文献
Sharp dynamic thermal gradient (∇T ≈ 45 °C mm−1) field‐driven assembly of cylinder‐forming block copolymer (c‐BCP) films filled with PS‐coated gold nanoparticles (AuNPs; dNP ≈ 3.6 nm, φNP ≈ 0–0.1) is studied. The influence of increasing AuNP loading fraction on dispersion and assembly of AuNPs within c‐BCP (PS‐PMMA) films is investigated via both static and dynamic thermal gradient fields. With φNP increasing, a sharp transition from vertical to random in‐plane horizontal cylinder orientation is observed due to enrichment of AuNPs at the substrate side and favorable interaction of PMMA chains with gold cores. Furthermore, a detachable capping elastomer layer can self‐align these random oriented PMMA microdomains into unidirectional hybrid AuNP/c‐BCP nanolines, quantified with an alignment order parameter, S.
New palladium(II) and platinum(II) complexes of saccharinate (sac) with 2-(2-pyridyl)benzimidazole (pybim) have been synthesized and characterized by elemental analysis and spectroscopic techniques. From the experimental studies, these complexes were formulated as [Pd(pybim)(sac)2] (1), and [Pt(pybim)(sac)2]·4H2O (2). The ground-state geometries of both complexes were optimized using density functional theory (DFT) methods at the B3LYP level. A bidentate pybim ligand together with two N-coordinated sac ligands form the square-planar MN4 coordination geometry around the palladium(II) and platinum(II) ions. The calculated IR and UV-vis spectral data have been correlated to the experimental results. Thermal analysis data support the molecular structures of both complexes. 相似文献
Two new copper(II) complexes of saccharinate (sac) with bis(2‐pyridylmethyl)amine (bpma) and N,N′‐bis[1‐(pyridin‐2‐yl)ethylidene]ethane‐1,2‐diamine (bapen), [Cu(bpma)(sac)2] · H2O ( 1 ) and [Cu(bapen)(sac)2] ( 2 ), were synthesized and characterized by elemental analysis, TG‐DTA, X‐ray diffraction, and UV/Vis and IR spectroscopy, respectively. In 1 , the copper(II) ion is coordinated by two N‐bonded sac ligands, and three nitrogen atoms of bpma, in a distorted square‐pyramidal coordination arrangement, whereas the arrangement around the copper ion in 2 is a distorted octahedron with two N‐coordinated sac ligands and a tetradentate bapen ligand. In addition to hydrogen bonding involving the water molecule in 1 , the mononuclear species of 1 and 2 are further connected by weak intermolecular C–H ··· π and C–H ··· O interactions to form a three‐dimensional network. Both complexes are luminescent at room temperature and their emissions seem to be due to ligand‐based π–π* transitions. 相似文献
Titanium dioxide (TiO2) thin films, with and without silver (Ag), were prepared on float glass via sol–gel processing. The float glass substrates
were pre-coated with a silica-barrier layer prior to the deposition of TiO2-based thin films. Silver nanoparticle incorporation into the TiO2 matrix was achieved by thermal reduction of Ag ions dissolved in a titanium-n-butoxide (Ti[O(CH2)3CH3]4) based sol during calcination in air at 250, 450 and 650 °C. Thin films were characterized using glancing incidence X-ray
diffraction, UV–visible spectroscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy. The effects of Ag concentration
and calcination temperature on microstructure and on chemical and physical properties of the thin films have been reported.
The size and chemical state of Ag particles, as well as the phase characteristics of the titania matrix were strongly influenced
by Ag concentration and calcination temperature. Results from this study can be utilized in both processing and structure-functional
property optimization of sol–gel based Ag-TiO2 thin films by aqueous routes. 相似文献