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71.
D. Gudat E. Niecke W. Sachs P. Rademacher 《Phosphorus, sulfur, and silicon and the related elements》2013,188(3-4)
Abstract UV- and He-I-p.e. spectra of phosphaalkenes 1 are discussed. 相似文献
72.
73.
In this paper the one-parameter subgroups of the several conformal transformation groups of the isotropic plane I
2 are investigated. In the first part we develop invariants of the groups such as differential of arc and curvature and in the second part we give a geometrical interpretation of these invariants. 相似文献
74.
Dr. A. Sachs 《Numerische Mathematik》1972,20(5):356-363
Summary We state three theorems concerning iterative methods for solving equations containing monotone, but not necessarily uniformly monotone operators in Hilbert space, which may be not Lipschitz bounded, thus extending results obtained by Sibony [9, 10]. We apply the method to a nonlinear elliptic Dirichlet problem of laminar flow theory of non Newtonian fluids, thus improving the rather experimental treatment given in Ames [1] and removing the condition of nonzero difference quotients assumed by Cryer [3]. 相似文献
75.
Véronique Delouille Rainer Von Sachs 《Annals of the Institute of Statistical Mathematics》2005,57(2):235-253
We estimate nonlinear autoregressive models using a design-adapted wavelet estimator. We show two properties of the wavelet
transform adapted to an autoregressive design. First, in an asymptotic setup, we derive the order of the threshold that removes
all the noise with a probability tending to one asymptotically. Second, with this threshold, we estimate the detail coefficients
by soft-thresholding the empirical detail coefficients. We show an upper bound on thel
2-risk of these soft-thresholded detail coefficients. Finally, we illustrate the behavior of this design-adapted wavelet estimator
on simulated and real data sets.
Financial support from the contract ‘Projet d'Actions de Recherche Concertées’ nr. 98/03-217 from the Belgian government,
and from the IAP research network nr. P5/24 of the Belgian State (Federal Office for Scientific, Technical and Cultural Affairs)
is gratefully acknowledged. 相似文献
76.
Krepelová A Reich T Sachs S Drebert J Bernhard G 《Journal of colloid and interface science》2008,319(1):40-47
To determine the influence of humic acid (HA), pH, and presence of atmospheric CO2 on the sorption of U(VI) onto kaolinite, the structure of the surface complexes was studied by U L III-edge extended X-ray absorption fine structure (EXAFS) spectroscopy. The best fits to the experimental EXAFS data were obtained by including two uranium coordination shells with two axial (O ax) and five equatorial (O eq) oxygen atoms at 1.77+/-0.02 and 2.34+/-0.02 A, respectively, and two coordination shells with one Al/Si atom each at 3.1 and 3.3 A. As in the case of the binary system U(VI)-kaolinite, uranium forms inner-sphere surface complexes by edge sharing with aluminum octahedra and/or silicon tetrahedra. HA and atmospheric CO2 as well as pH had no influence on the EXAFS structural parameters in the pH range of 5-8. Despite the presence of HA, U(VI) prefers to sorb directly onto kaolinite and not to HA that is bound to the clay surface. X-ray photoelectron spectroscopy (XPS) measurements of kaolinite particles that had been exposed to HA suspensions showed that significant parts of the kaolinite surface are not covered by HA. 相似文献
77.
Kucerka N Pencer J Sachs JN Nagle JF Katsaras J 《Langmuir : the ACS journal of surfaces and colloids》2007,23(3):1292-1299
High-resolution small-angle X-ray scattering (SAXS), complemented by small-angle neutron scattering (SANS) and dynamic light scattering (DLS) experiments, was used to study the effect of curvature on the bilayer structure of dioleoyl-phosphatidylcholine (DOPC) and dioleoyl-phosphatidylserine (DOPS) unilamellar vesicles (ULVs). Bilayer curvature, as a result of finite vesicle size, was varied as a function of vesicle radius and determined by DLS and SANS measurements. Unilamellarity of large DOPC ULVs was achieved by the addition of small amounts (up to 4 mol %) of the charged lipid, DOPS. A comparison of SANS data over the range of 0.02 < q <0.2 A-1 indicated no change in the overall bilayer thickness as a function of ULV diameter (620 to 1840 A). SANS data were corroborated by high-resolution (0.06 < q <0.6 A-1) SAXS data for the same diameter ULVs and data obtained from planar samples of aligned bilayers. Both the inner and outer leaflets of the bilayer were found to be indistinguishable. This observation agrees well with simple geometric models describing the effect of vesicle curvature. However, 1220-A-diameter pure DOPS ULVs form asymmetric bilayers whose structure can most likely be rationalized in terms of geometrical constraints coupled with electrostatic interactions, rather than curvature alone. 相似文献
78.
Meng F Wiener MC Sachs JR Burns C Verma P Paweletz CP Mazur MT Deyanova EG Yates NA Hendrickson RC 《Journal of the American Society for Mass Spectrometry》2007,18(2):226-233
Label-free LC-MS profiling is a powerful quantitative proteomic method to study relative peptide abundances between two or more biological samples. Here we demonstrate the use of a previously described comparative LC-MS method, differential mass spectrometry (dMS), to analyze high-resolution Fourier transform mass spectrometry (FTMS) data for detection and quantification of known peptide differences between two sets of complex mixtures. Six standard peptides were spiked into a processed plasma background at fixed ratios from 1.25:1 to 4:1 to make two sets of samples. The resulting mixtures were analyzed by microcapillary LC-FTMS and dMS. dMS successfully identified five out of the six peptides as statistically significant differences (p 相似文献
79.
Geovani N. Grapiglia Ekkehard W. Sachs 《Computational Optimization and Applications》2017,68(3):555-577
A general class of non-monotone line search algorithms has been proposed by Sachs and Sachs (Control Cybern 40:1059–1075, 2011) for smooth unconstrained optimization, generalizing various non-monotone step size rules such as the modified Armijo rule of Zhang and Hager (SIAM J Optim 14:1043–1056, 2004). In this paper, the worst-case complexity of this class of non-monotone algorithms is studied. The analysis is carried out in the context of non-convex, convex and strongly convex objectives with Lipschitz continuous gradients. Despite de nonmonotonicity in the decrease of function values, the complexity bounds obtained agree in order with the bounds already established for monotone algorithms. 相似文献
80.
Steudtner R Müller K Schmeide K Sachs S Bernhard G 《Dalton transactions (Cambridge, England : 2003)》2011,40(44):11920-11925
The complexation of U(VI) with humic acid (HA) in aqueous solution has been investigated at an ionic strength of 0.1 M (NaCl) in the pH range between pH 2 and 10 at different carbonate concentrations by attenuated total reflection Fourier-transform infrared (ATR FT-IR) spectroscopy. For the first time, the formation of binary and ternary U(VI) humate complexes was directly verified by in situ spectroscopic measurements. The complex formation constants for the binary U(VI) humate complex (UO(2)HA(II)) and for the ternary U(VI) mono hydroxo humate complex (UO(2)(OH)HA(I)) as well as the ternary U(VI) dicarbonato humate complex (UO(2)(CO(3))(2)HA(II)(4-)) determined from the spectroscopic data amount to log β(0.1 M) = 6.70 ± 0.25, log β(0.1 M) = 15.14 ± 0.25 and log β(0.1 M) = 24.47 ± 0.70, respectively, and verify literature data. 相似文献