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101.
Consider the catalytic super-Brownian motion X
ϱ (reactant) in ℝ
d
, d≤3, which branching rates vary randomly in time and space and in fact are given by an ordinary super-Brownian motion ϱ (catalyst).
Our main object of study is the collision local time L = L
[ϱ,Xϱ]
(d(s,x) )of catalyst and reactant. It determines the covariance measure in themartingale problem for X
ϱ and reflects the occurrence of “hot spots” of reactant which can be seen in simulations of X
ϱ. In dimension 2, the collision local time is absolutely continuous in time, L(d(s,x) ) = ds K
s
(dx). At fixed time s, the collision measures K
s
(dx) of ϱ
s
and X
s
ϱ
have carrying Hausdorff dimension 2. Spatial marginal densities of L exist, and, via self-similarity, enter in the long-term randomergodic limit of L (diffusiveness of the 2-dimensional model). We alsocompare some of our results with the case of super-Brownian motions withdeterministic
time-independent catalysts.
Received: 2 December 1998 / Revised version: 2 February 2001 / Published online: 9 October 2001 相似文献
102.
Mohamed Ali Ayedi Yves Le Bigot Souhir Abid Rachid El Gharbi Michel Delmas 《合成通讯》2013,43(16):2127-2133
We report here a novel, one-pot, two-step reductive amination of aldehydes for the atom-economical synthesis of primary amines. The amination step has been carried out with hydroxylammonium chloride and does not require the use of a base. In the subsequent reduction step, a metal zinc/hydrochloride acid system has been used. This method is applicable to both aliphatic and aromatic aldehydes. The operational simplicity, the short reaction times, and the mild reaction conditions add to the value of this method as a practical alternative to the reductive amination of aldehydes. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file. 相似文献
103.
Sym-phthaloyl chloride under controlled cathodic reduction is converted into trans-[1(3H)-isobenzofuranone, 3-(3-oxo-1(3H)-isobenzofuranylidene)]: trans-biphthalyl in 65% yield. 相似文献
104.
The use of potassium carbonate leads to a stereoselective synthesis of epoxyesters in the presence of substituted thiolanium salt and a carbonyl compound in a solid-liquid low hydrated organic medium. 相似文献
105.
We consider the height process of a Lévy process with no negative jumps, and its associated continuous tree representation.
Using Lévy snake tools developed by Le Gall-Le Jan and Duquesne-Le Gall, with an underlying Poisson process, we construct
a fragmentation process, which in the stable case corresponds to the self-similar fragmentation described by Miermont. For
the general fragmentation process we compute a family of dislocation measures as well as the law of the size of a tagged fragment.
We also give a special Markov property for the snake which is of its own interest.
相似文献
106.
107.
Bromine-modified oligodeoxynucleotides (ODNs) were fragmented in the electrospray source to study the influence of brominated bases on fragmentation. Several 13-mer ODNs containing a brominated pyrimidine base, BrdU (5-bromodeoxyuridine) or BrdC (5-bromodeoxycytidine), were analyzed. Low cone voltage fragmentation yields a loss of the brominated base with a preferential loss for the brominated base closer to the 5'-end (2-position > 4-position > 12-position) as well as a preferential loss of BrdU over BrdC. Higher cone voltage produces backbone fragmentation with complementary a(n)-base and w(m) ions close to the brominated base. On the basis of these observations, we located the brominated base in the sequence for all of the ODNs studied. 相似文献
108.
We consider the exploration process associated to the continuous random tree (CRT) built using a Lévy process with no negative
jumps. This process has been studied by Duquesne, Le Gall and Le Jan. This measure-valued Markov process is a useful tool
to study CRT as well as super-Brownian motion with general branching mechanism. In this paper we prove this process is Feller,
and we compute its infinitesimal generator on exponential functionals and give the corresponding martingale.
The research of the second author was partially supported by NSERC Discovery Grants of the Probability group at Univ. of British
Columbia. 相似文献
109.
The latest investigations on the acylation of aromatic and heteroaromatic structures (1,2,3) have shown that, in the case of furan, the yield and the selectivity observed are poor. Furylic ketones are however derivatives of major interest (4–6). 相似文献
110.
Based on segmentation-recombination principle, a specific optical device is designed to homogenize a highpower CO2 laser beam which is used as a heating source. 相似文献