323 research outputs found

    Direct Observation of High-Spin States in Manganese Dimer and Trimer Cations by X-ray Magnetic Circular Dichroism Spectroscopy in an Ion Trap

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    The electronic structure and magnetic moments of free Mn2+_2^+ and Mn3+_3^+ are characterized by 2p2p x-ray absorption and x-ray magnetic circular dichroism spectroscopy in a cryogenic ion trap that is coupled to a synchrotron radiation beamline. Our results show directly that localized magnetic moments of 5 μB\mu_B are created by 3d5(6S)3d^5 (^6\mathrm{S}) states at each ionic core, which are coupled in parallel to form molecular high-spin states via indirect exchange that is mediated in both cases by a delocalized valence electron in a singly-occupied 4s4s derived orbital with an unpaired spin. This leads to total magnetic moments of 11 μB\mu_B for Mn2+_2^+ and 16 μB\mu_B for Mn3+_3^+, with no contribution of orbital angular momentum

    Biogeography and ecology of geographically distant populations of sibling Cryptocephalus leaf beetles

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    Different populations of two closely related species, Cryptocephalusflavipes and C. bameuli, from western (Alps, Apennines and Pyrenees) and central Europe (Poland, Ukraine and Pannonia) were analysed. On the basis of DNA sequences from two genes, cox1 and ef1-alpha, distinctiveness of both species was confirmed. Nevertheless, possible hybrids were identified in Carpathian mountains. We found a significant genetic differentiation among populations of C. flavipes and C. bameuli from distant regions but a high genetic similarity between populations of C. bameuli from north and south of the Carpathians. Demographic estimates suggest a past population expansion in the case of C. bameuli and a recent one for C. flavipes, possibly occurred during Pleistocene and Holocene, respectively. Distribution modelling showed that C. flavipes is typically present in the mountain systems, whereas C. bameuli is associated with hilly areas of central and eastern Europe. Based on the present data, Last Glacial Maximum refugia of both species were located in the Alpine region and Black Sea coasts, but on different elevations. The characterization of the insect diet, through a DNA metabarcoding approach targeting the trnL plant intron, demonstrated a significant differentiation of food preferences between the two species, as well as between geographic populations within the species

    To confirm certain land claims in the Territory of New Mexico. (To accompany bill H.R. no. 195.)

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    36-1Private Land ClaimsReport on Land Claims in New Mexico. [1068] Depredations of the Apaches and other tribes of the Southwest; etc.1860-8

    Sylvester Tiffany

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    25-2Invalid PensionsReport : Petition of S. Tiffany. [333] British and Indians.1838-
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