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131.
Pure rotational coherent anti-Stokes Raman scattering (CARS) experiments have been performed in acetylene for temperatures
ranging from 294 to 582 K, and in mixtures of acetylene and nitrogen in the mole fraction range of 0.06–0.32 for acetylene
at room temperature. The experimental spectra are evaluated by a least-square fitting to libraries of theoretically calculated
spectra using two different Raman linewidth models, one with and one without dependence on the rotational quantum number J. It is found that a J-dependent model is favourable, both regarding temperature measurements in pure acetylene, and simultaneous acetylene concentration
and temperature measurements in different mixtures of acetylene and nitrogen. For the temperature measurements performed in
pure acetylene the temperature inaccuracy is generally less than 2% when the J-dependent model for the Raman linewidths is used. It is found that fitting the value of the non-resonant susceptibility significantly
improves the quality of the spectral fits and is a requirement for high temperature accuracy with the present model. The evaluated
concentrations show a maximum error of 13% on a relative scale. Potential sources of systematical errors both regarding measured
temperatures and acetylene concentrations are discussed.
Received: 8 June 1999 / Revised version: 3 Spetember 1999 / Published online: 3 November 1999 相似文献
132.
Wang E Ma Z Zhang Z Henriksson P Inganäs O Zhang F Andersson MR 《Chemical communications (Cambridge, England)》2011,47(17):4908-4910
A new low band gap polymer (E(g) = 1.6 eV) with alternating thiophene and isoindigo units was synthesized and characterized. A PCE of 3.0% and high open-circuit voltage of 0.89 V were realized in polymer solar cells, which demonstrated the promise of isoindigo as an electron deficient unit in the design of donor-acceptor conjugated polymers for polymer solar cells. 相似文献
133.
S?ren?AsmussenEmail author Mats?Pihlsg?rd 《Methodology and Computing in Applied Probability》2005,7(4):439-457
This paper deals with queues and insurance risk processes where a generic service time, resp. generic claim, has the form
U ∧ K for some r.v. U with distribution B which is heavy-tailed, say Pareto or Weibull, and a typically large K, say much larger than
. We study the compound Poisson ruin probability ψ(u) or, equivalently, the tail
of the M/G/1 steady-state waiting time W. In the first part of the paper, we present numerical values of ψ(u) for different values of K by using the classical Siegmund algorithm as well as a more recent algorithm designed for heavy-tailed claims/service times,
and compare the results to different approximations of ψ(u) in order to figure out the threshold between the light-tailed regime and the heavy-tailed regime. In the second part, we
investigate the asymptotics as K → ∞ of the asymptotic exponential decay rate γ = γ
(K) in a more general truncated Lévy process setting, and give a discussion of some of the implications for the approximations.
AMS 2000 Subject Classification Primary 68M20, Secondary 60K25
†Partially supported by MaPhySto—A Network in Mathematical Physics and Stochastics, founded by the Danish National Research
Foundation.
An erratum to this article is available at . 相似文献
134.
Mats Rudemo 《Journal of Mathematical Analysis and Applications》1973,44(3):581-611
Recursive equations are derived for the conditional distribution of the state of a Markov chain, given observations of a function of the state. Mainly continuous time chains are considered. The equations for the conditional distribution are given in matrix form and in differential equation form. The conditional distribution itself forms a Markov process. Special cases considered are doubly stochastic Poisson processes with a Markovian intensity, Markov chains with a random time, and Markovian approximations of semi-Markov processes. Further the results are used to compute the Radon-Nikodym derivative for two probability measures for a Markov chain, when a function of the state is observed. 相似文献
135.
136.
Takwa M Larsen MW Hult K Martinelle M 《Chemical communications (Cambridge, England)》2011,47(26):7392-7394
Based on molecular modelling, the enzyme Candida antarctica lipase B was redesigned as a catalyst for the ring opening polymerization of D,D-lactide. Two mutants with 90-fold increased activity as compared to the wild-type enzyme were created. In a preparative synthesis of poly(D,D-lactide) the mutants greatly improved the rate and the degree of polymerization. 相似文献
137.
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140.
Rie Fredrickson Takagi Daisy Torino Hjelmqvist Mats Johnsson Sven Lidin 《Solid State Sciences》2009,11(1):13-17
The compounds CaCo2Te3O8Cl2, SrCo2Te3O8Cl2 and SrNi2Te3O8Cl2 were synthesized via solid–gas reactions and investigated using single-crystal X-ray diffraction. While the compound CaCo2Te3O8Cl2 formed large enough single crystals to allow for a detailed structural analysis, crystals of the Sr-containing compounds yielded evidence that they are isostructural. CaCo2Te3O8Cl2 crystallizes in the monoclinic system, space group P21/c, a = 6.537(2) Å, b = 9.088(2) Å, c = 19.500(9) Å, β = 113.36(4)°, Z = 4. It exhibits [CoO5Cl] helical chains along the [010] direction, connected by [CaO8] polyhedra, [TeO3E] tetrahedra and [TeO4E] trigonal bipyramids (the lone pair of electrons on TeIV is designated as E) to form a layer. The layers are held together only by weak van der Waals forces; the shortest interlayer distance is a Te?Cl contact of 3.432(4) Å. 相似文献