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1.
Consider the one-dimensional catalytic super-Brownian motion X (called the reactant) in the catalytic medium
which is an autonomous classical super-Brownian motion. We characterize
both in terms of a martingale problem and (in dimension one) as solution of a certain stochastic partial differential equation.
The focus of this paper is for dimension one the analysis of the longtime behavior via a mass-time-space rescaling. When scaling
time by a factor of K, space is scaled by K
η and mass by K
−η. We show that for every parameter value η ≥ 0 the rescaled processes converge as K→ ∞ in path space. While the catalyst’s limiting process exhibits a phase transition at η = 1, the reactant’s limit is always the same degenerate
process.
相似文献
2.
Let p≥2, n
1≤⋅⋅⋅≤n
p
be positive integers and
be independent planar Brownian motions started uniformly on the boundary of the unit circle. We define a p-fold intersection exponent ς
p
(n
1,…,n
p
), as the exponential rate of decay of the probability that the packets
, i=1,…,p, have no joint intersection. The case p=2 is well-known and, following two decades of numerical and mathematical activity, Lawler et al. (Acta Math. 187:275–308,
2001) rigorously identified precise values for these exponents. The exponents have not been investigated so far for p>2. We present an extensive mathematical and numerical study, leading to an exact formula in the case n
1=1, n
2=2, and several interesting conjectures for other cases. 相似文献
3.
S. Sachsenberg Th. Klenke W. E. Krumbein E. Zeeck 《Fresenius' Journal of Analytical Chemistry》1992,342(1-2):163-166
Summary A ligand exchange liquid/liquid extraction method using dithiocarbamate complexes is elaborated for the graphite furnace atomic absorption spectrometry (GF-AAS) of seawater and marine interstitial water. Palladium is used for the exchange. This metal ensures a rapid and quantitative back-extraction. It simultaneously works as matrix modifier in the GF-AAS analysis. The proposed method is evaluated in the analysis of lead, copper, nickel, and cadmium in CASS-II marine reference seawater and samples from the North Sea. A microanalytical variant of the method is applied in marine interstitial water analysis down to sample volumes of 500 l. 相似文献
4.
Remco van der Hofstad Achim Klenke Wolfgang König 《Journal of statistical physics》2002,106(3-4):477-520
A polymer chain with attractive and repulsive forces between the building blocks is modeled by attaching a weight e
–
for every self-intersection and e
/(2d) for every self-contact to the probability of an n-step simple random walk on
d
, where , >0 are parameters. It is known that for d=1 and > the chain collapses down to finitely many sites, while for d=1 and < it spreads out ballistically. Here we study for d=1 the critical case = corresponding to the collapse transition and show that the end-to-end distance runs on the scale
n
=
(log n)–1/4. We describe the asymptotic shape of the accordingly scaled local times in terms of an explicit variational formula and prove that the scaled polymer chain occupies a region of size
n
times a constant. Moreover, we derive the asymptotics of the partition function. 相似文献
5.
6.
Andreas Greven Achim Klenke Anton Wakolbinger 《Probability Theory and Related Fields》2001,120(1):85-117
We study the longtime behaviour of interacting systems in a randomly fluctuating (space–time) medium and focus on models
from population genetics. There are two prototypes of spatial models in population genetics: spatial branching processes and
interacting Fisher–Wright diffusions. Quite a bit is known on spatial branching processes where the local branching rate is
proportional to a random environment (catalytic medium).
Here we introduce a model of interacting Fisher–Wright diffusions where the local resampling rate (or genetic drift) is proportional
to a catalytic medium. For a particular choice of the medium, we investigate the longtime behaviour in the case of nearest
neighbour migration on the d-dimensional lattice.
While in classical homogeneous systems the longtime behaviour exhibits a dichotomy along the transience/recurrence properties
of the migration, now a more complicated behaviour arises. It turns out that resampling models in catalytic media show phenomena
that are new even compared with branching in catalytic medium.
Received: 15 November 1999 / Revised version: 16 June 2000 / Published online: 6 April 2001 相似文献
7.
Abstract Prolonged treatment of tetra-O-acetyl-1, 5-anhydro-hex-1-enitols (“tetra-O-acetyl-hydroxy-glycals”) 3 and 5 with BF3 in CH2Cl2 at RT lead to anomeric mixtures of the title compounds 2 and 4a, the α-anomer 4a dominating. Reaction of 5 gave the higher yields of 4a (71%) and 2 (12%), the results being accounted mechanistic grounds. The same reaction performed in an aromatic solvent, like toluene, gave rise to competing C-alkylation., The ortho and para-tolyl derivatives 6 and 7, also with enone structure, were isolated in a combined maximum yield of 40% from 5. β-Enone 2 was also prepared in moderate yield by thermolysis of β-d-glucopyranose pentaacetate (1). In this case no α-anomer 4a was detected. 相似文献
8.
The generation of 0.5 mJ femtosecond laser pulses by coherent combining of two high power high energy fiber chirped-pulse amplifiers is reported. The system is running at a repetition frequency of 175 kHz producing 88 W of average power after the compressor unit. Polarizing beam splitters have been used to realize an amplifying Mach-Zehnder interferometer, which has been stabilized with a H?nsch-Couillaud measurement system. The stabilized system possesses a measured residual rms phase difference fluctuation between the two branches as low as λ/70 rad at the maximum power level. The experiment proves that coherent addition of femtosecond fiber lasers can be efficiently and reliably performed at high B-integral and considerable thermal load in the individual amplifiers. 相似文献
9.
Zimmer O. Schmidt-Wellenburg P. Fertl M. Wirth H.-F. Assmann M. Klenke J. van den Brandt B. 《The European Physical Journal C - Particles and Fields》2010,67(3-4):589-599
The European Physical Journal C - We report experiments on the production of ultracold neutrons (UCN) in a converter of superfluid helium coated with fluorinated grease (fomblin). We employed our... 相似文献
10.
Baabe D. Klauß H.-H. Hillberg M. Klenke J. Litterst F.J. Bremers H. Hesse J. 《Hyperfine Interactions》1999,120(1-8):263-266
Hyperfine Interactions - We performed Mössbauer spectroscopy on the ternary alloy system (Fe0.65Ni0.35)1-xMnx in applied external magnetic fields. From the hyperfine field distributions the... 相似文献