79 resultados para Mn2
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Synthetic procedures for new mixed-donor macrocycle compounds were reported. The macrocyclic compounds were used in solvent extraction metal picrates such as Ag+, Hg2+, Cd2+, Zn2+, Cu2+, Ni2+, Mn2+, Pb2+, and Co2+. The metal picrate extractions were investigated at 250.1C with the aid of UV-visible spectrometry. It was found that 6,7,9,10,12,13,23,24-octahydro-19H,26Hdibenzo[h,t](1,4,7,13,16,22,10,19) dioxatetrathiadiazasiclotetracosine-20,27(21H,28H)-dione showed selectivity towards Ag+, Hg2+, and Cd2+ among the other metals. The extraction constants (Log Kex) and complex compositions were determined for the Ag+ and Hg2+ complexes for this compound and 9,10,12,13,23,24,26,27,29,30-decahydro-5H,15H-dibenzo-[h,w][1,4,7,13,16,19,25-,10,22] dioxapentathiadiazacycloheptacosine-6,16(7H,17H)-dione.
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3 200~3 600 m185,1B1394,873 U/mL16S rDNA,(Bacillus subtilis):60,pH 8.0,3040,40~60,;Mn2+Mg2+Ca2+,Hg2+Fe3+Cu2+Zn2+Fe2+;PMSF,
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Mn2+Manganese-enhanced magnetic resonanceimagingMEMRI4.7TEEG MEMRIMn2+Ca2+Ca2+Ca2+Mg2+ (MILDVAN and COHN, 1963; EISINGER et al., 1965)Mn2+MEMRIMn2+Mn2+Mn2+80mMol/L200nlGlu 0.5mM/L-aminobutyric acidGABA 0.5M/LMn2+Mn2+ 358n=510Mn2+Mn2++Glu/Mn2+Mn2+20p=0.016, student t-test, *p <0.05Mn2++GABAp=0.047, *p<0.05Mn2+Ca2+Mn2+Mn2+Mn2+Mn2+ 5Mn2+3p0.0558p=0.004*p<0.052432Mn2+80mM/L,200nl510%(10mg/kg, 12)MEMRI16Mn2+( one-way ANOVA, Post Hoc Dunnetts C Tests), F (6,28)=7.242, P<0.001)357Mn2+(one-way ANOVA, *p<0.05)EEGgammaEEG(Two-way ANOVA, F(1,10)=13.626,p=0.006)1gammaEEG35gammaEEGMEMRI
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Different effects of divalent metal ions on electrochemiluminescence (ECL) sensor with Ru(bPY)(3)(2+) immobilized in Eastman-AQ membrane were investigated. Mg2+,Ca2+ and Fe2+ can elevate the ECL of Ru(bpY)(3)(2+)/proline; while metal ions that underwent redox reactions on the electrode such as Mn2+ and Co2+ presented intensive quenching effects on Ru(bpy)(3)(2+) ECL. Also, the quenching effect of Mn2+ on the ECL sensor with Ru(bpY)(3)(2+) immobilized in Eastman-AQ membrane enhanced to about 30-folds compared with the case that Ru(bpy)(3)(2+) was dissolved in phosphate buffer, and the enhanced quenching effects of Mn2+ were studied.
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Four transition-metal-amine complexes incorporating indium thioarsenates with the general formula M(tren)InAsS4 (M=Mn, Co, and Zn) and a noncondensed AsS33- unit have been prepared and characterized. Single-crystal X-ray diffraction analyses show that compound 1 (M=Mn) crystallizes in the triclinic crystal system (space group: P (1) over bar) and consists of a one-dimensional (1D) inorganic (1)(infinity){[InAsS4](2-)} chain and [Mn(tren)](2+) groups bonded to the opposite sides of an eight-membered In2As2S4 ring along the backbone of the infinite inorganic chains. Compounds 2 (M=Mn), 3 (M=Zn), and 4 (M=Co) are isomorphous molecular compounds. They all crystallize in the monoclinic crystal system (space group: P2(1)/c). The Mn2+ cation of [Mn(tren)](2+) in 1 has a distorted octahedral environment, while the transition-metal cations of [M(tren)](2+) in the other three compounds locate in trigonal-bipyramidal environments.
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In this paper, we report a facile route which is based Oil tuning doping concentration of Mn2+ ions in ZnS nanocrystals, to achieve deliberate color modulation from blue to orange-yellow under single-wavelength excitation. X-ray diffraction (XRD), transmission electron microscopy (TEM), as well as photoluminescence (PL) spectra were employed to characterize the obtained samples. In this process, the relative emission intensities of both ZnS host (blue) and Mn2+ dopant (orange-yellow) are sensitive to the Mn2+ doping concentration, due to the energy transfer from ZnS host to Mn2+ dopant. As a result of fine-tuning of these two emission components, white emission can be realized for Mn2+-doped ZnS nanocrystals. Furthermore.
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The Sr3Al2O5Cl2:Ce3+,Eu2+ phosphors were prepared by solid state reaction. The obtained phosphors exhibit a strong absorption in the UV-visible region and have two intense emission bands at 444 and 609 nm. The energy transfer from the Ce3+ to Eu2+ ions was observed, and the critical distance has been estimated to be about 24.5 A by spectral overlap method. Furthermore, the developed phosphors can generate lights from yellow-to-white region under the excitation of UV radiation by appropriately tuning the activator content, indicating that they have potential applications as an UV-convertible phosphor for white light emitting diodes.
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Mn2+NaYMnNaY,(IR)X(XRD).Mn2+3.2%.4.99.7mmolLs-1,Gd-DTPA,MRI..
Sol-Gel Preparation of Zn2 Si04Mn Phosphor Layers on Silica Spheres and Their Luminescent Properties
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The synthesis and luminescence properties of Zn2SiO4:Mn phosphor layers on spherical silica spheres,i.e.,a kind of core-shell complex phosphor,Zn2SiO4:Mn@SiO2 were described.Firstly,monodisperse silica spheres were obtained via the Stober method by the hydrolysis of tetraethoxysilane(TEOS)Si(OC2H5)4 under base condition (using NH4OH as the catalyst).Secondly,the silica spheres were coated with a Zn2SiO4:Mn phosphor layer by a Pechini sol-gel process.X-ray diffraction(XRD),scanning electron microscope(SEM),energy-dispersive X-ray spectrum(EDS) and photoluminescence(PL) were employed to characterize the resulting complex phosphor.The results comfirm that 1000 annealed sample consists of crystalline Zn2SiO4:Mn shells and amorphous SiO2 cores.The phosphor show the green emission of Mn2+ at 521nm corresponding 4T1(4G)-6A1(6S) transition,and the possible luminescence mechanism is proposed.
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The effect of metal cations in solution on the oxidation of methanol on the electrode surface of platinum is a neglected aspect to direct methanol fuel cell (DMFC). In this paper, a smooth platinum electrode absorbing metal cations as the working electrode was applied to investigate the methanol oxidation with the cyclic voltammetry (CV) in 1.0 mol L-1 H2SO4. From the analysis of experiment, it is found that the cations, Li+, Ce4+, Mn2+, Ni2+, Cu2+, have some negative effect on the catalytic oxidation of methanol on the surface of platinum. The degree of the effect from different cations was analyzed.
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BaMgAl10 O17R(R =Eu ,Mn) , , 16 5nm ,Mn2 + 170 2 40nm ,Eu2 + 4f 5d 2 10 40 0nm
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LaMgAl11O19R(R=Mn,Tb),,170nm,Mn2+170510nm,Tb3+4f 5d170250nm147nm,,
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The influences of different cations on plasmid DNA network structures on a mica substrate were investigated by atomic force microscopy (AFM). Interactions between the DNA strands and mica substrate, and between the DNA strands themselves were more strongly influenced by the complex cations (Fe(phen)(3)(2+), Ni(phen)(3)(2+), and Co(phen)(3)(3+)) than by the simple cations (Mg2+, Mn2+, Ni2+, Ca2+, Co3+). The mesh height of the plasmid DNA network was higher when the complex cations were added to DNA samples. The mesh size decreased with increasing DNA concentration and increased with decreasing DNA concentration in the same cation solution sample. Hence, plasmid DNA network height can be controlled by selecting different cations, and the mesh size can be controlled by adjusting plasmid DNA concentration.
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( AFM) 1 986 [1,2 ] , , .DNA AFM , DNA , , [3,4 ] . DNA AFM , . ( Mg2 + ,Ba2 + ,Mn2 + Ca2 + [5] ) , , , , , , DNA , DNA . AFM , Ni( phen) 2 + 3 DNA , .11 .1Ni( phen) 2 + 3 Ni2 SO4 ( ) 1 ,1 0 - ( ) .PBR32 2 /pst ...
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ZnGa2 O4ZnGa2 O4Mn2 + /Eu3 + ,X(XRD) (TG DTA)ZnGa2 O4ZnGa2 O4Mn2 + /Eu3 + XRD , 5 0 0 , 70 0ZnGa2 O4 , 5 0 0ZnGa2 O4Mn2 + 4 5 0nm 5 0 6nm ,ZnGa2 O4 ,Mn2 + 4T16A1ZnGa2 O4Eu3 + Eu3 + , 6 13nm ,Eu3 + 5D0 7F2 ZnGa2 O4Mn2 + /Eu3 + ,
