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Ulrich Dierkes 《manuscripta mathematica》1986,56(3):313-331
Plateau's problem for surfaces of prescribed mean curvature will be considered in regions which are not necessarily H-convex. 相似文献
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Ulrich Dierkes 《Inventiones Mathematicae》1995,122(1):453-473
We here prove pointwise curvature estimates for minimal hypersurfaces in singular spaces, using the integral curvature estimate and a generalized Simons inequality which were established recently. A further basic ingredient is a new Sobolev type inequality for stationary hypersurfaces.Oblatum 19-IX-1994This research was supported by the Deutsche Forschungsgemeinschaft through a Heisenberg award. Part of the work described here was carried out during visits to Dipartimento Matematica Applicata, University of Firenze and Department of Mathematics, Stanford University. The author would like to express his gratitude to both institutions for their kind hospitality and support. Also it is a pleasure to thank the referee for his useful comments concerning the formulation of the main theorem. 相似文献
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T. Mathew R. N. Datta W. K. Dierkes J. W. M. Noordermeer W. J. van Ooij 《Plasma Chemistry and Plasma Processing》2008,28(2):273-287
Carbon black is widely used as an active filler in the rubber industry to improve the physical properties of rubber. The surface
energy of carbon black is high compared to that of various elastomers like styrene–butadiene rubber (SBR), butadiene rubber
(BR) and ethylene–propylene–diene rubber (EPDM). The work aims at reducing the surface energy of carbon black by modifying
its surface for application especially in rubber blends. The present paper looks into the possibility of using plasma polymerisation
of acetylene as a surface modification technique for carbon black in comparison with silica. Thermogravimetric analysis, wetting
behaviour with various liquids of known surface tension and time of flight secondary ion mass spectrometry (ToF-SIMS) were
used to characterise the carbon black before and after surface modification. The study shows that surface modification of
carbon black by plasma polymerisation is difficult in comparison with silica, unless treated for long duration. The mechanistic
aspects of the surface modification and the importance of active sites on the carbon black surface for effective modification
are discussed in the paper. 相似文献
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Shailesh Ramdeehul Peter Dierkes Rafael Aguado Paul C. J. Kamer Piet W. N. M van Leeuwen John A. Osborn 《Angewandte Chemie (International ed. in English)》1998,37(22):3118-3121
Preferential rotation in substrate—palladium intermediates in a catalyzed asymmetric allylic alkylation is proposed to be responsible for both the observed kinetic resolution of the racemic allylic acetate starting material as well as the high selectivity found in the enantiodiscriminating product-forming step [Eq. (a)]. 相似文献
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Because changes in cell volume might disturb the normal function of animal cells, most cells are endowed with volume-regulating mechanisms. Experimentally induced changes in cell volume are often paralleled by changes in the membrane potential, which might affect a variety of transport processes across the cell membrane and, in turn, volume regulation [1, 2]. We have shown previously that multi-barrelled ion-selective microelectrodes are useful tools for measurement of cell volume and the intracellular concentrations of ions that might be relevant to volume regulation [1]. To investigate whether voltage-dependent transport processes are involved in cell-volume regulation we combined the potentiometric technique of ion-selective microelectrodes with the voltage-clamp technique. This combination enables simultaneous recording of cell volume, relevant intracellular ion concentrations, and ion currents across the cell membrane at a fixed membrane potential. 相似文献
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Peter Dierkes Shailesh Ramdeehul Laurent Barloy Andre De Cian Jean Fischer Paul C. J. Kamer Piet W. N. M van Leeuwen John A. Osborn 《Angewandte Chemie (International ed. in English)》1998,37(22):3116-3118
Palladium complexes of the chiral diphosphanes 1 and 2 which possess a rigid backbone and a large bite angle catalyze the alkylation of allyl compounds with both high enantioselectivities and reaction rates, particularly with less sterically demanding substrates. 1 : R=Me, X=S; 2 : R=H, X=C(CH3)2. 相似文献