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91.
Fred van de Velde Fanny Weinbreck Marijke W. Edelman Erik van der Linden R. Hans Tromp 《Colloids and surfaces. B, Biointerfaces》2003,31(1-4):159-168
Confocal scanning laser microscopy (CSLM) has been used to study the behaviour of mixtures of proteins, gelatine, whey proteins and β-lactoglobulin, and polysaccharides, dextran, gellan gum, carrageenan, gum Arabic, and starch. CSLM proved to be a suitable technique to visualise the microstructure of these (phase separated) mixtures in two and three-dimensional images. Contrast through fluorescence is obtained either by covalent labelling (polysaccharides and proteins) or non-covalent labelling (proteins and starch). Double and triple labelling allows the visualisation of individual components in a complex mixture of biopolymers. 相似文献
92.
Tibor Horvath Anthony Linden Fumihiko Yoshizaki ConradHans Eugster Peter Rüedi 《Helvetica chimica acta》2004,87(9):2346-2353
Antioxidative‐activity‐guided fractionation of extracts of the aerial parts of the title plant yielded the two novel abietanoid diterpenoids 11,20‐dihydroxysugiol (=11,12,20‐trihydroxyabieta‐8,11,13‐trien‐7‐one; 3 ) and 1,11‐epoxy‐6,12‐dihydroxy‐20‐norabieta‐1(10),5,8,11,13‐pentaen‐7‐one ( 4 ) in addition to 11‐hydroxysugiol (=12‐O‐demethylcryptojaponol=11,12‐dihydroxyabieta‐8,11,13‐trien‐7‐one; 2 ) and the main constituent carnosolon (=6,20‐epoxy‐6,11,12‐trihydroxyabieta‐8,11,13‐trien‐7‐one; 1 ). The structures were established on the basis of spectroscopic, chiroptic, and X‐ray crystallographic evidence. 相似文献
93.
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Selective determinations of several metal ions by means of amperometric complex-formation titrations employing normal pulse polarography with a DME appear to be possible. Concentrations down to 3 x 10(-7)M have been determined with adequate accuracy. In alkaline medium deaeration is necessary; in acidic medium it can be omitted. 相似文献
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97.
The steady Navier–Stokes equations in primitive variables are discretized in conservative form by a vertex-centred finite volume method Flux difference splitting is applied to the convective part to obtain an upwind discretization. The diffusive part is discretized in the central way. In its first-order formulation, flux difference splitting leads to a discretization of so-called vector positive type. This allows the use of classical relaxation methods in collective form. An alternating line Gauss–Seidel relaxation method is chosen here. This relaxation method is used as a smoother in a multigrid method. The components of this multigrid method are: full approximation scheme with F-cycles, bilinear prolongation, full weighting for residual restriction and injection of grid functions. Higher-order accuracy is achieved by the flux extrapolation method. In this approach the first-order convective fluxes are modified by adding second-order corrections involving flux limiting. Here the simple MinMod limiter is chosen. In the multigrid formulation the second-order discrete system is solved by defect correction. Computational results are shown for the well known GAMM backward-facing step problem and for a channel with a half-circular obstruction. 相似文献
98.
M. Rashdan A. Faessler N. Ohtsuka R. Linden W. Wadia M. Ismail 《Zeitschrift für Physik A Hadrons and Nuclei》1988,330(4):417-421
Using a complex energy density functional derived from the Reid soft-core potential, the changes in nuclear shapes of two colliding208Pb are investigated. At each separation distanceR, the total binding energy of the Pb + Pb system is minimized w.r.t. the quadrupole deformation and diffuseness parameters of nuclear densities. It is found that the nuclear shapes are strongly affected by the nuclear and Coulomb interactions. A sudden transition occurs from oblate to prolate shapes around R16.8fm and a smooth one from prolate to oblate shapes aroundR?11.76 fm. 相似文献
99.
The analytical applicability of a mixed sulfide copper-selective electrode has been evaluated, with special attention given to end-point indication in compleximetric titrations. In acidic medium, several metals can be titrated satisfactorily. The determination of calcium and magnesium in alkaline medium is discussed briefly. Selectivity coefficients are presented for several metal ions in acidic medium. 相似文献
100.
Tanya Tsoncheva Mika Linden Jessica Rosenholm Christo Minchev 《Reaction Kinetics and Catalysis Letters》2005,86(2):275-280
Summary Ni-modifiedlarge poremesoporous silicasarecharacterized by XRD, N2physisorption and TPR with H2. Theeffectof the supportpore structure on their catalytic behaviorin methanol decomposition to H2, CO and CH4is studied. 相似文献