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101.
102.
Maren Lorenzen Peter Bsecke Christian Riekel Karen Reynders Harry Reynaers Noel Overbergh 《Macromolecular rapid communications》1996,17(3):189-192
Small-angle X-ray scattering using synchrotron radiation at pressures up to 700 MPa has been performed on triblock-copolymer gels, polystyrene-rubber-polystyrene with poly(ethylene/butylene) as the rubber mid-blocks. A 2-stage pressure behaviour could be verified by comparison of the experimental data with the Tait-equation and a model of pressure screening. 相似文献
103.
Christian Decker Danielle Decker Trieu Nguyen Thi Viet Hien Le Xuan 《Macromolecular Symposia》1996,102(1):63-71
Different types of tridimensional polymer networks have been synthetised by photoinitiated cationic polymerisation of vinyl ether and epoxy-functionalised oligomers and polymers. The polymerisation kinetics was followed by real-time infrared (RTIR) spectroscopy, a technique that records directly conversion versus time profiles in a timescale as short as 1 s. The addition of a diacrylate monomer was shown to accelerate the ring-opening polymerisation of epoxidized polyisoprene, with formation of interpenetrating polymer networks having well contrasted properties. A dual polymer network has been generated by photocrosslinking of a polyisoprene functionalised with both epoxy and acrylate groups. 相似文献
104.
Spartan 4.1.1 ist ein Molecular Modelling-Programm, das “state of the art” Rechenverfahren mit einer exzellenten Visualisierung der Ergebnisse bei gleichzeitig akzeptablem Preis verbindet. 相似文献
105.
106.
Navindra Keerthisinghe Matthew S. Christian Anna A. Berseneva Gregory Morrison Vladislav V. Klepov Mark D. Smith Hans-Conrad zur Loye 《Molecules (Basel, Switzerland)》2022,27(1)
The solvothermal synthesis, structure determination and optical characterization of five new metastable halometallate compounds, [1,10-phenH][Pb3.5I8] (1), [1,10-phenH2][Pb5I12]·(H2O) (2), [1,10-phen][Pb2I4] (3), [1,10-phen]2[Pb5Br10] (4) and [1,10-phenH][SbI4]·(H2O) (5), are reported. The materials exhibit rich structural diversity and exhibit structural dimensionalities that include 1D chains, 2D sheets and 3D frameworks. The optical spectra of these materials are consistent with bandgaps ranging from 2.70 to 3.44 eV. We show that the optical behavior depends on the structural dimensionality of the reported materials, which are potential candidates for semiconductor applications. 相似文献
107.
Thomas Rigotti Daniel P. Schwinger Raphaela Graßl Christian Jandl Thorsten Bach 《Chemical science》2022,13(8):2378
In intramolecular [2+2] photocycloaddition reactions, the two tethered olefins can approach each other in a straight or in a crossed fashion. Despite the fact that the latter reaction mode leads to intriguing, otherwise inaccessible bridged skeletons, there has so far not been any enantioselective variants thereof. This study concerned the crossed [2+2]-photocycloaddition of 2-(alkenyloxy)cyclohex-2-enones to bridged cyclobutanes. It was found that the reaction could be performed with high enantioselectivity (80–94% ee) under visible light conditions when employing a chiral rhodium Lewis acid as a catalyst (2 mol%).An enantioselective crossed [2+2] photocycloaddition is presented which proceeds under visible light irradiation in the presence of a chiral Lewis acidic metal complex. Chelation of two oxygen atoms to the metal centre accounts for the observed enantioface differentiation. 相似文献
108.
109.
Christian Grosche 《Fortschritte der Physik》1994,42(6):509-584
In this paper path integration in two- and three-dimensional spaces of constant curvature is discussed: i.e. the flat spaces R2 and R3, the two- and three-dimensional sphere and the two- and three-dimensional pseudosphere. We are going to discuss all coordinates systems where the Laplace operator admits separation of variables. In all of them the path integral formulation will be stated, however in most of them an explicit solution in terms of the spectral expansion can be given only on a formal level. What can be stated in all cases, are the propagator and the corresponding Green function, respectively, depending on the invariant distance which is a coordinate independent quantity. This property gives rise to numerous identities connecting the corresponding path integral representations and propagators in various coordinate systems with each other. 相似文献