356 research outputs found

    Dissertation on iodine

    Get PDF

    1862-03-22 George Anson writes General Hodsdon regarding supplies for Eli Rowe of Brewer

    Get PDF
    https://digitalmaine.com/cw_me_1st_cav/1230/thumbnail.jp

    Synthesis and Supramolecular Structure of a (5-(3-(1H-tetrazol-5-yl)phenyl)-1H-tetrazole) Cobalt Complex

    Get PDF
    The reaction of CoCl2·6H2O with m-BDTH2 (1,3-benzeneditetrazol-5-yl) leads to [Co(C8H6N8)2(H2O)2(CH3CN)2]Cl2 (1). Both tetrazolic groups remain protonated existing in a 1H tautomeric form. A trifurcated chlorine atom and stacking interactions assemble compound 1 into a three-dimensional network

    Tetranuclear CuII2DyIII2 coordination cluster as Suzuki (C–C) coupling reaction promoter

    Get PDF
    The air stable and high yielding tetranuclear coordination cluster [CuII2DyIII2L4(NO3)2(CH3CN)2]·2(CH3CN) promotes the Suzuki coupling reaction of phenylboronic acid with substituted aryl halides in environmentally benign conditions

    Synthesis, structure and electrochemical characterization of the isopolytungstate (W4O16) held by MnII anchors within a superlacunary crown heteropolyanion {P8W48}

    Get PDF
    An isopolyanion {W4O16} within archetypal {P8W48} heteropolyanion assembly [(P8W48O184)(W4O16)K10Li4Mn10Na(H2O)50Cl2] 15- (Mn10W4-P8W48) has been synthesized by the reaction of the cyclic superlacunary anion [H7P8W48O184] 33− and Mn(ClO4)2.6H2O in I M LiCl soultion medium at pH 8. The isolated compound has been characterized by single crystal X-ray crystallography, powder X-ray diffraction (PXRD), Fourier-transform infrared (FTIR) spectroscopy, elemental analysis and thermogravimetric analysis. Electrochemical studies were also performed on Mn10W4-P8W48 confirmed the presence of Mn centres bonded to the tunsgtic framework. The novel polyanion [(P8W48O184)(W4O16)K10Li4Mn10Na(H2O)50Cl2] 15- is the first example of macrocyclic complex where an isopolyanion (W4O16) 8- is embedded within in the inner cavity of the {P8W48} and is placed in position by six MnII cations as anchors. Whereas, the exocyclic coordination of the four MnII atoms to {P8W48} yields extended structure by linking neighbouring polyanions through {W−O−Mn−O−W} bridges. Further, the polyanion Mn10W4-P8W48 is the first derivative of {P8W48} with six MnII ions (largest) coordinated to the inner side the crown ring as anchors

    The effect of reionization on direct measurements of the mean free path

    Full text link
    Recent measurements of the ionizing photon mean free path (MFP) based on composite quasar spectra may point to a late end to reionization at z<6z<6. These measurements are challenging, however, because they rely on assumptions about the proximity zones of the quasars in the analysis. For example, some of the z∌6z\sim 6 quasars in the composite might have been close to large-scale regions where reionization was still ongoing ("neutral islands"), and it is unclear how this would affect the measurements. We address the question here with mock MFP measurements from radiative transfer simulations. We find that, even in the presence of neutral islands, the inferred MFP tracks to within 30%30 \% the true attenuation scale of the spatially averaged IGM, which includes opacity from both the ionized medium and the islands. During reionization, this scale is always shorter than the MFP in the ionized medium. The inferred MFP is sensitive at the <50%< 50\% level to assumptions about the quasar environments and lifetimes for realistic models. We demonstrate that future analyses with improved data may require explicitly modeling the effects of neutral islands on the composite spectra, and we outline a method for doing this. Lastly, we quantify the effects of neutral islands on Lyman-series transmission, which has been modeled with optically thin simulations in previous MFP analyses. Neutral islands can suppress transmission at λrest<912\lambda_{\rm rest} < 912 \r{A} significantly, up to a factor of 2 for zqso=6z_{\rm qso} = 6 in a plausible reionization scenario, owing to absorption by many closely spaced lines as quasar light redshifts into resonance. However, the suppression is almost entirely degenerate with the spectrum normalization, thus does not significantly bias the inferred MFP.Comment: 11 pages, 8 figures, submitted to MNRA
    • 

    corecore