779 resultados para Taxation and government property
Resumo:
We report a simple method for novel flower-like In4SnS8 nanostructure synthesis. A flower-like In4SnS8 nanostructure was synthesized via a one-pot hydrothermal route using the biomolecule L-cysteine as a sulfur source. The structure was characterized using X-ray powder diffraction (XRPD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption analysis and photoluminescence spectra. This flower-like structure consists of crosslinked nanoflakes and possesses good thermostability and a high BET surface area.
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A new kind of polyfluorene copolymers, poly(2,7-(9,9-dioctyl-fluorene)-alt-5,5 -(4',7'-di-2-thienyl-2',1',3',-benzothiadiazole) (PFDTBT), was prepared. The introduction of ZnO nanoparticles with perfect wurtzite crystal character into PFDTBT makes the resulted single-layer photovoltaic device to perform a significant photovoltaic response. Among the tested devices, the best performance is observed for that containing 60 wt% of ZnO nanoparticles, which has a photocurrent density of 1.17 mu A/cm(2), an open circuit voltage of 0.81 V. a fill factor of 0.09 and a power conversion efficiency of 0.009%. The results show that the polyfluorene derivatives/ZnO nanoparticles hybrid composites are excellent fluorescence and photovoltaic materials.
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YVO4 nanocrystals doped with 10.0 mol% Eu3+ have been synthesized from an aqueous solution of ( Y, Eu)( NO3) (3) and NH4VO3 with or without ultrasonic irradiation. The ultrasonic irradiation has a strong effect on the morphology of the YVO4: Eu particles. The spindle-like particles with an equatorial diameter of 90 - 150 nm and a length of 250 - 300 nm could be obtained with ultrasonic irradiation, whereas only nanoparticles were produced without ultrasonic irradiation. The photoluminescence intensity of YVO4: Eu of the spindle-like particles was largely improved compared with that of the nanoparticles. The possible formation mechanism of the spindle-like particles of YVO4: Eu with the application of ultrasonic irradiation was discussed in this paper.
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One inorganic-organic hybrid and two host-guest complexes were synthesized from calix[4] arene tetra acetic ether derivative( C60H80O12, L) and potassium polyoxometalates. The structures of the complexes were characterized with the elemental analysis, IR, TG-DTA and X-crystallographic. X-ray crystallographic studies reveal the formation of an ionic crystal, which contains a calix-cluster and calix-cluster-calix line array, and belongs to a typical inorganic-organic hybrid ( complex 1) or has a host-guest structure ( complex 2 and 3). The results of cyclic voltammograms at different scanning rates showed that the anode peak current of complex 1 was proportional to the square root of the scanning rate and the charge transfer process was controlled by pervasion. The anode peak current of complexes 2 and 3 was proportional to the scanning rate and the charge transfer process was controlled by the surface. The results suggest that there are consanguineous relationship between the anode reaction and the structure.
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A novel 3D supramolecular assembly constructed from decavanadate and caffeine building blocks, (NH4)(2)(C8H10N4O2)(4)[H4V10O28].2H(2)O (1), has been synthesized in aqueous solution and characterized by elemental analysis, IR, H-1 NMR, V-51 NMR, TG-DTA, and single crystal X-Ray diffraction. The compound 1 crystallizes in monoclinic system, space group P2(1)/n, a = 15.801(1) Angstrom, b = 12.914(1) Angstrom, c = 15.913(2) Angstrom, beta = 113.55degrees, V = 2976.4 (5) Angstrom(3), Z = 2, R = 0.0498 with 6818 reflections. Water molecules, ammonium ions, and caffeine act as "cement" linking the polyanions into 1D chain along the c-axis by hydrogen bonding. In compound 1, extensive hydrogen-bond contacts and strong pi-pi interactions lead to an ordered 3D supramolecular framework. TG-DTA curves indicate that the weight loss of the complex can be divided into three stages.
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A new photoluminescent heterobimetallic Zn(II)-Ag(I) cyano-bridged coordination polymer, [Ag5Zn2(tren)(2)(CN)(9)] (tren = tris(2-aminoethyl)amine) (1), has been synthesized and structurally characterized. It features rare linear pentameric unit of dicyanoargentate(I) ions assembled by d(10)-d(10) interaction as building blocks. Solid state emission spectrum of I shows strong ultraviolet luminescence with emission peak in the range of 376 nm.
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New series of oxides, La3MMo2O12 (M = In, Ga and Al), have been prepared by the solid-state reaction. The composition and elemental distribution were analyzed by the energy-dispersive X-ray (EDX) analysis. As determined by the X-ray diffraction (XRD), these compounds have similar crystal structures that can be indexed on a monoclinic cell at room temperature. AC impedance spectra and the DC electrical conductivity measurements in various atmospheres indicate that they are oxide ion conductors with ionic conductivities between 10(-2) and 10(-3) S/cm at 800 degrees C. The conductivity decreases in the order of La3GaMo2O12 > La3AlMo2O12 > La3InMo2O12, implying that the effect of cell volume and polarization associated with In3+, Ga3+ and Al3+ play an important role in the anion transport of these materials. The reversible phase transition was observed in all these compounds as confirmed by the differential thermal analysis (DTA) and dilatometric measurements.
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An asymmetrical double Schiff-base Cu(II) mononuclear complex, HCuLp (H(3)Lp is N-3-carboxylsalicylidene-N'-5-chlorosalicylaldehyde-1,3-diaminopropane) and a heterometal trinuclear complex with double molecular structure (CuLp)(2)Co center dot 5H(2)O have been synthesized and characterized by means of elemental analyses, IR and electronic spectra. The crystal structure of the heterotrinucler complex was determined by X-ray analysis. Each asymmetric unit within the unit cell of the complex contains two heterotrinuclear neutral molecules (a) [CuLpCoCuLp], (b) [(CuLpH(2)O) CoCuLp] and four uncoordinated water molecules. In the two neutral molecules, the central Co2+ ions are located at the site of O-6 with a distorted octahedral geometry, one terminal Cu2+ ion (Cu(3)) at the square-pyramidal environment of N2O3, and the other three at the square planar coordination geometry with N2O2 donor atoms. Magnetic properties of the heterotrinucler complex have been determined in the temperature range 5-300 K, indicating that the interaction between the central Co2+ ion and the outer Co2+ ions is antiferromagnetic.
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The chain structure, spherulite morphology, and theological property of LL-DPE-g-AA were studied by using electronspray mass spectroscopy, C-13-NMR, and rheometer. Experimental evidence proved that AA monomers grafted onto the LLDPE backbone formed multiunit AA branch chains. It was found that AA branch chains could hinder movement of the LLDPE main chain during crystallization. Spherulites of LLDPE became more anomalous because of the presence of AA branch chains. Rheological behavior showed that AA branch chains could act as an inner plasticizer at the temperature range of 170-200 degreesC, which made LLDPE-g-AA easy to further process. (C) 2001 John Wiley & Sons, Inc.
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A series of Sr2+ doped perovskite like oxides La2-xSrxCuO4-lambda (x = 0 similar to 1) were prepared, the structure, lattice parameters, content of Cu3+, oxygen vacancies created by Sr2+ substitution and composition of these complex oxides were studied by XRD and iodic titration method. The redox ability,active oxygen species and surface image were evaluated and analyzed with TPD, TG, XPS and SEM measurements. The catalytic activity for ammonia oxidation over these oxides was tested, and the relationship among the catalytic properties, structure, nonstoichiometric oxygen,redox ability and surface behavior were correlated and some information on the mechanism of ammonia oxidation was obtained.
Resumo:
A new method for the preparation of polyalkyl and polyarenefullerene derivatives C-60(RH)(n)(R=Bu,n=1-3; R=Ph,n=1-10) by the reaction of C-60 with organotin hydride in toluene is described. Another series of products of stannanes R(a)Sn(b)H(c) (R=Bu, a=3-8, b=1-4, c=0-3 R=Ph, a=3-11, b=1-5, c=0-4) were also obtained, which shows that C-60 can catalyze polymerization of organic-tin. These products were determined by mass and infrared spectrometry. And the possible reaction mechanisms are discussed.
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In2CuO5 is isostructural to Y2Cu2O5 both in its crystal and magnetic structure. In and Y can be substituted by each other in any ratio to make new compounds Y2-xInxCu2O5 (x = 0-2) which were identified by XRD and IR spectrum. The structural change in Y2-x
Analysis of the expression and antioxidative property of a peroxiredoxin 6 from Scophthalmus maximus
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Peroxiredoxins (Prxs) are a group of antioxidant proteins that protect cells from oxidative damage caused by various peroxides. To date, six different isoforms of peroxiredoxin (Prx1 to Prx6) have been identified, of which, Prx6 belongs to the 1-Cys Prx subfamily. Although Prx6 of several fish species have been reported at sequence level, there are very few documented studies on the potential function of fish Prx6. In this report, we describe the identification and analysis of a Prx6 homologue, SmPrx6, from turbot Scophthalmus maximus. The full length cDNA of SmPrx6 contains a 5'- untranslated region (UTR) of 60 bp, an open reading frame of 666 bp, and a 3'-UTR of 244 bp. The deduced amino acid sequence of SmPrx6 shares 81-87% overall identities with known fish Prx6. In silico analysis identified in SmPrx6 a conserved Prx6 catalytic motif, PVCTTE, and the catalytic triads putatively involved in peroxidase and phospholipase A2 activities. Expression of SmPrx6 was detected in most fish organs, with the highest expression levels found in blood and heart and the lowest level in spleen. Experimental challenges with bacterial pathogens and poly(I:C) upregulated SmPrx6 expression in liver and spleen in a manner that is dependent on the challenging agent and the tissue type. Treatment of cultured primary hepatocytes with H2O2 enhanced SmPrx6 expression in a dose-dependent manner. Recombinant SmPrx6 expressed in and purified from Escherichia coli exhibited thiol-dependent antioxidant activity and could protect cultured hepatocytes from H2O2-induced oxidative damage. Taken together, these results indicate that SmPrx6 is a Prx6 homologue with antioxidative property and is likely to be involved in both cellular maintenance and protective response during host immune defense against bacterial infection. (C) 2010 Elsevier Ltd. All rights reserved.
Resumo:
A mass of geological, geophysical and geochemical data and information from the Okinawa Trough area are collected for comprehensive research in the study area from East China to Okinawa Trough and then to Ryukyu Island Are region. According to the seismic tomography result (P and S wave) and the processing result of free-air and Bouguer gravity anomaly and magnetic anomaly data in the study area, the comprehensive interpretation is carried out. The Moho depth distribution of the study area is obtained by the inversion calculation based on gravity data using the Harmonious Series method. The crust properties are analyzed. Meantime, some Cenozoic basalt data from Kuandian (NE China), Hannuoba (North China), Minxi (South China), Penghu Islands (Taiwan Strait), Okinawa Trough and Japan Island Arc regions are chosen to make the comparison research on element- isotopes. The result indicates that the lithosphere thickness in the Okinawa Trough area has obviously decreased, where a Low -velocity layer of upper-mantle has reached the Moho interface and the metasometized asthenosphere has formed. The research result on element- isotopes shows that the characteristic of the crust in the Okinawa Trough area is different from that in East China area and the Ryukyu Island Arc area. It is considered that the crust in the Okinawa Trough area belongs to the transition type, which is quite similar to the feature of the oceanic crust.