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71.
Hanspeter Schmidli 《Insurance: Mathematics and Economics》2010,46(2):281-289
A risk process that can be Markovised is conditioned on ruin. We prove that the process remains a Markov process. If the risk process is a PDMP, it is shown that the conditioned process remains a PDMP. For many examples the asymptotics of the parameters in both the light-tailed case and the heavy-tailed case are discussed. 相似文献
72.
Abstract The knowledge of water exchange reaction mechanism in aqueous solutions of Gd3+ polyaminocarboxylates is important for the understanding of the relatively slow water exchange rates measured for these complexes. Variable ressure measurements show a change of mechanism from associatively activated on [Gd(H2O)8]3+ and [Gd(PDTA)(H2O2)2]? to probably limiting dissociative on the MRI contrast agents [Gd(DOTA)(H2O)]?, [Gd(DTPA)(H2O)]2? and [Gd(DTPA-BMA)(H2O)]. 相似文献
73.
Experimental data from an excised larynx are analyzed in the light of nonlinear dynamics. The excised larynx provides an experimental framework that enables artificial control and direct observation of the vocal fold vibrations. Of particular interest in this experiment is the coexistence of two distinct vibration patterns, which closely resemble chest and falsetto registers of the human voice. Abrupt transitions between the two registers are typically accompanied by irregular vibrations. Two approaches are presented for the modeling of the excised larynx experiment; one is the nonlinear predictive modeling of the experimental time series and the other is the biomechanical modeling (three-mass model) that takes into account basic mechanisms of the vocal fold vibrations. The two approaches show that the chest and falsetto vibrations correspond to two coexisting limit cycles, which jump to each other with a change in the bifurcation parameter. Irregular vibrations observed at the register jumps are due to chaos that exists near the two limit cycles. This provides an alternative mechanism to generate chaotic vibrations in excised larynx experiment, which is different from the conventionally known mechanisms such as strong asymmetry between the left and right vocal folds or excessively high subglottal pressure. 相似文献
74.
Dominik Jacob Kathrin Thüring Aurellia Galliot Virginie Marchand Adeline Galvanin Akif Ciftci Karin Scharmann Michael Stock Jean‐Yves Roignant Sebastian A. Leidel Yuri Motorin Raffael Schaffrath Roland Klassen Mark Helm 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(28):9666-9670
75.
Kehr SC Cebula M Mieth O Härtling T Seidel J Grafström S Eng LM Winnerl S Stehr D Helm M 《Physical review letters》2008,100(25):256403
We demonstrate the imaging of ferroelectric domains in BaTiO3, using an infrared-emitting free-electron laser as a tunable optical source for scattering scanning near-field optical microscopy and spectroscopy. When the laser is tuned into the spectral vicinity of a phonon resonance, ferroelectric domains can be resolved due to the anisotropy of the dielectric properties of the material. Slight detuning of the wavelength gives rise to a contrast reversal clearly evidencing the resonant character of the excitation. The near-field domain contrast shows that the orientation of the dielectric tensor with respect to the sample surface has a clear influence on the near-field signal. 相似文献
76.
77.
78.
Monte L. Helm Kristi D. Loveday Charles M. Combs Elizabeth L. Bentzen Donald G. VanDerveer Robin D. Rogers Gregory J. Grant 《Journal of chemical crystallography》2003,33(5-6):447-455
We report here two crystal structures of heavy metal complexes containing macrocyclic trithioethers. The trithioether, 10S3 (1,4,7-trithiacyclodecane) complexes Pb(II) to form a compound of the formula [Pb(10S3)](ClO4)2(H2O) (Compound 1). This behavior contrasts the related trithioether 9S3 (1,4,7-trithianonane), which readily forms a bis Pb(II) complex. Crystals of Compound 1 consist of [Pb(10S3)(H2O)]2+ units and perchlorate anions which are weakly bound to the Pb2+ center. The two perchlorate anions serve as bidentate ligands to a single lead(II) center. However, a third oxygen in one of the perchlorates also serves as a bridging group between two lead(II) centers, linking the [Pb(10S3)(H2O)]2+ units into zigzag chains. Thus, a highly irregular nine-coordinate (S3O6) environment around the Pb2+ion is formed by the three sulfur donors from the 10S3 ligand, one coordinated water, and five oxygens from three different perchlorate anions. Also, the lone pair electrons on the Pb center are stereochemically active. Compound 2, [Cd(9S3)2](ClO4)2 2 CH3NO2, forms a distorted octahedral structure with unusual hexakis(thioether) coordination to the Cd(II) center. Bond distances and angles are very comparable to those found in the structure of the tetrafluoroborate salt of the complex cation. (1): P21/c, a = 9.1720(6) Å, b = 15.7687(11) Å, c = 11.8427(8) Å, = 93.0180(10) , V = 1710.4 (2) Å3, Z = 4; (2): P21/c , a = 10.4305(10) Å, b = 15.2059(6) Å, c = 9.4919(7) Å, = 99.324(9), V = 1485.6(2) Å3, Z = 2. 相似文献
79.
Wenger D Gerecke AC Heeb NV Naegeli H Zenobi R 《Analytical and bioanalytical chemistry》2008,390(8):2021-2029
An in vitro reporter gene assay based on human breast cancer T47D cells (ER-CALUX) was applied to examine the ability of diesel exhaust to induce or inhibit estrogen receptor (ER)-mediated gene expression. Exhaust from a heavy-duty diesel engine was either treated by iron- or copper/iron-catalyzed diesel particulate filters (DPFs) or studied as unfiltered exhaust. Collected samples included particle-bound and semivolatile constituents of diesel exhaust. Our findings show that all of the samples contained compounds that were able to induce ER-mediated gene expression as well as compounds that suppressed the activity of the endogenous hormone 17beta-estradiol (E2). Estrogenic activity prevailed over antiestrogenic activity. We found an overall ER-mediated activity of 1.63 +/- 0.31 ng E2 CALUX equivalents (E2-CEQs) per m(3) of unfiltered exhaust. In filtered exhaust, we measured 0.74 +/- 0.07 (iron-catalyzed DPF) and 0.55 +/- 0.09 ng E2-CEQ m(-3) (copper/iron-catalyzed DPF), corresponding to reductions in estrogenic activity of 55 and 66%, respectively. Our study demonstrates that both catalytic DPFs lowered the ER-mediated endocrine-disrupting potential of diesel exhaust. 相似文献
80.
Interactions and dynamics in ionic liquids 总被引:1,自引:0,他引:1
Stoppa A Hunger J Buchner R Hefter G Thoman A Helm H 《The journal of physical chemistry. B》2008,112(16):4854-4858
Precise dielectric spectra have been determined at 25 degrees C over the exceptionally broad frequency range of 0.1 相似文献