Room temperature phosphorescence from a platinum(II) diimine bis(pyrenylacetylide) complex

Room temperature phosphorescence has been observed in a synthetically facile Pt(II) complex, Pt(dbbpy)(CtriplebondC-pyrene)(2) (dbbpy = 4,4'-di(tert-butyl)-2,2'-bipyridine; CtriplebondC-pyrene = 1-ethynylpyrene), in fluid solution. The static and time-resolved absorption and luminescence data are consistent with phosphorescence emerging from the appended CtriplebondC-pyrenyl units following excitation into the low energy dpi Pt --> pi* dbbpy metal-to-ligand charge transfer absorption bands.     

Multiresolution Analysis and Radon Measures on a Locally Compact Abelian Group

A multiresolution analysis is defined in a class of locally compact abelian groups G. It is shown that the spaces of integrable functions and the complex Radon measures M(G) admit a simple characterization in terms of this multiresolution analysis.     

Shear induced phase transition in PbO under high pressure

We have studied the structural behavior of lead monoxide (PbO) as a function of pressure via angular dispersive X-ray diffraction employing two different pressure transmitting media that were quasi-hydrostatic (N₂) and non-hydrostatic (MgO), respectively. Besides litharge (-PbO) and massicot (β-PbO), which are both stable at ambient pressure, there is an orthorhombic γ-PbO phase which appears upon application of pressure to -PbO. We have found that the orthorhombic γ-PbO phase is favored by shear stress under non-hydrostatic conditions. -PbO shows strong anisotropy in compressibility. The a-axis is rather incompressible with a linear stiffness coefficient of K_a0=540(30) GPa whereas the c-axis stiffness is K_c0=25(1) GPa. The bulk modulus of -PbO is K₀=23.1(3) GPa and its derivative .     

Identifying the underlying structure and dynamic interactions in a voting network

We analyse the structure and behaviour of a specific voting network using a dynamic structure-based methodology which draws on Q-Analysis and social network theory. Our empirical focus is on the Eurovision Song Contest over a period of 20 years. For a multicultural contest of this kind, one of the key questions is how the quality of a song is judged and how voting groups emerge. We investigate structures that may identify the winner based purely on the topology of the network. This provides a basic framework to identify what the characteristics associated with becoming a winner are, and may help to establish a homogenous criterion for subjective measures such as quality. Further, we measure the importance of voting cliques, and present a dynamic model based on a changing multidimensional measure of connectivity in order to reveal the formation of emerging community structure within the contest. Finally, we study the dynamic behaviour exhibited by the network in order to understand the clustering of voting preferences and the relationship between local and global properties.     

Synthesis and Pd-catalyzed coupling of1-C-stannylated glycals

Abstract

1-Tributylstannyl glycals were applied as versatile tools in the Pd(0)-mediated synthesis of glycal phthalonitrile conjugates. Likewise, selective homo-coupling of 1-tributylstannyl glycals furnishing C1-C1’ linked glycal dimers was investigated by using Pd(II)-species. For both Stille type couplings the rate-accelerating effect of copper(I) thiophene-2-carboxylate (CuTC) was exploited. The synthesis of stannylated glycal precursors was significantly improved by establishing a one-pot two-step procedure via glycosyl sulfoxides.     

Gauß' wissenschaftliches Tagebuch 1796–1814

Ohne ZusammenfassungMit Anmerkungen herausgegebenHierzu ein Faksimile     

Ueber den Stand der Herausgabe von Gauss' Werken

Ohne ZusammenfassungAbgedruckt aus den Nachrichten der K. Gesellschaft der Wissenschaften zu Göttingen, Geschäftliche Mittheilungen, 1898, Heft I. (Oeffentliche Sitzung vom 30. April 1898.)