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41.
We suggest a novel method for significant improvement of fiber Bragg grating (FBG) spectral characteristics based on compensation of repeatable errors during the grating writing process. The method is based on an open loop scheme in which a test grating is written first and then a corrected design is obtained and implemented by writing another (compensated) grating. The results are presented for a FBG dispersion compensator. 相似文献
42.
43.
The behavior of the symmetrical ethane-bridged bis(Zn porphyrin) (1) has been investigated at the air-water interface. The molecular organization of floating films of pure 1 and its mixture with amphiphilic substances, such as arachidic acid and n-octadecylamine, was inspected by means of surface pressure-area isotherms, Brewster angle microscopy and reflection spectroscopy in the UV-Vis region. The overall results suggest the presence in all cases of mainly the anti conformer of 1 even when the dimer was spread on pure water, through the ligation of water molecules to the zinc atoms in the axial positions. It was also demonstrated for the first time that the syn-to-anti conformational transition of the porphyrin dimer can be accelerated by the ligation of suitable amphiphiles even at the liquid-air interface. In particular, it is noted that n-octadecylamine, and arachidic acid (to a lesser extent), added to the system as amphiphiles, drive the syn ? anti equilibrium of 1 towards the anti form through the axial ligation of the amino or carboxylate group to the zinc atoms. 相似文献
44.
A.A. Borovkov 《Probability Theory and Related Fields》2003,125(3):421-446
Let be independent identically distributed random variables with regularly varying distribution tails:
where α≤ min (1,β), and L and L
W
are slowly varying functions as t→∞. Set S
n
=X
1
+⋯+X
n
, ˉS
n
= max
0≤ k ≤ n
S
k
. We find the asymptotic behavior of P
(S
n
> x)→0 and P
(ˉS
n
> x)→0 as x→∞, give a criterion for ˉS
∞
<∞ a.s. and, under broad conditions, prove that P (ˉS
∞
> x)˜c V(x)/W(x).
In case when distribution tails of X
j
admit regularly varying majorants or minorants we find sharp estimates for the mentioned above probabilities under study.
We also establish a joint distributional representation for the global maximum ˉS
∞
and the time η when it was attained in the form of a compound Poisson random vector.
Received: 4 June 2001 / Revised version: 10 September 2002 / Published online: 21 February 2003
Research supported by INTAS (grant 00265) and the Russian Foundation for Basic Research (grant 02-01-00902)
Mathematics Subject Classification (2000): 60F99, 60F10, 60G50
Key words or phrases: Attraction domain of a stable law – Maximum of sums of random variables – Criterion for the maximum of sums – Large deviations 相似文献
45.
46.
47.
Dmitrii S. Yufit Judith A. K. Howard Sergei I. Kozhushkov Rafael R. Kostikov Armin de Meijere 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(8):968-969
The central three‐membered ring in the title compound, trans‐1,1′,1′′‐cyclopropane‐1,2,3‐triyltris(cyclopropanol), C12H18O3, shows pronounced asymmetry of the bond lengths, which is induced by the different orientations of the substituents. A network of hydrogen bonds links the molecules into sheets. 相似文献
48.
Siberian Mathematical Journal - 相似文献
49.
Konstantin A. Borovkov David C.M. Dickson 《Insurance: Mathematics and Economics》2008,42(3):1104-1108
We derive a closed-form (infinite series) representation for the distribution of the ruin time for the Sparre Andersen model with exponentially distributed claims. This extends a recent result of Dickson et al. [Dickson, D.C.M., Hughes, B.D., Zhang, L., 2005. The density of the time to ruin for a Sparre Andersen process with Erlang arrivals and exponential claims. Scand. Actuar. J., 358–376] for such processes with Erlang inter-claim times. The derivation is based on transforming the original boundary crossing problem to an equivalent one on linear lower boundary crossing by a spectrally positive Lévy process. We illustrate our result in the cases of gamma, mixed exponential and inverse Gaussian inter-claim time distributions. 相似文献
50.
Vitalii S. Tkach Dmitrii S. Suslov Gennadii V. Ratovskii Tuczek Felix 《Journal of organometallic chemistry》2008,693(12):2069-2073
A series of palladium complexes of general formula [(Acac)PdL1L2]+A−, where L1, L2 = phosphines and A = BF4, CF3SO3, were synthesized. Preliminary studies show that the complexes are active in selective dimerization of styrene and addition polymerization of norbornene. 相似文献