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91.
We have demonstrated a spectroscopic technique for simultaneously obtaining broad spectral bandwidth and high frequency resolution absorption measurements, with 5 μs temporal resolution, continuously for tens of microseconds in an apparatus with no active stabilization. The technique utilizes two passive air-gap etalons to imprint two frequency comb patterns onto a single pulsed light source. The air-gap etalons also serve as cavity ringdown cells increasing the sensitivity of the absorption spectroscopy by increasing the interrogation path length. Here, we demonstrate the operation of the spectrometer utilizing a ~0.15 cm(-1) bandwidth pulsed dye laser and two nearly identical 300 MHz free-spectral range confocal air-gap etalons each with a finesse of ~1 × 10(5), to investigate the (1,1,3) overtone of water and the R(7) transition of the O(2) b(1)Σ(g)(+)←X(3)Σ(g)(-) (2,0) band with high spectral resolution. 相似文献
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93.
George E. Strecker 《Applied Categorical Structures》2000,8(3):559-578
Flows with respect to a functor F are introduced as a common generalization of the concepts of F-co-structured sinks and small F-co-structured sources. Appropriate factorization structures for functors are investigated and used to obtain several results that characterize coadjoint functors that have domains with various completeness conditions. When the functor in question is an identity functor, these results reduce to earlier results of Herrlich and Meyer for flows in a category. Functors of the type in question are shown to be nicely behaved with respect to composition. The dual notion of wolfs with respect to a functor is introduced, as is the concept of (co)limit with respect to a functor. 相似文献
94.
Peter Brucker Sigrid Knust Duncan Roper Yakov Zinder 《Mathematical Methods of Operations Research》2000,52(3):369-387
Problems with unit execution time tasks and two identical parallel processors have received a great deal of attention in
scheduling theory. In contrast to the conventional models, where each task requires only one processor, we consider a situation
when a task may require both processors simultaneously. For problems without precedence constraints we present several polynomial
time algorithms which complement recent results of Lee and Cai. We also show that the introduction of precedence constraints
leads to NP-hardness results for maximum lateness and mean flow time objective functions. For the maximum lateness problem,
a family of algorithms, based upon the idea of modified due dates, is considered. The worst case behaviour of these algorithms
is analysed, and it is shown that the same upper bound is tight for each algorithm of this family. 相似文献
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A MRD CI procedure has been used to calculate several electronic states of the hydroperoxyl radical. The basis set is of double-zeta plus polarization quality augmented with s- and p-type bond and Rydberg functions. The vertical excitation energies of the lowest eight doublet and six quartet states are reported. Oscillator strengths for transitions form the ground to upper doublet states were calculated. A cut of the potential energy surfaces along the OOH fragmentation pathway is used to discuss the mechanisms of HO2 photodissociation below 6.4 eV. Arguments are presented which indicate O(1D) rather than O(3P) is the primary dissociation product, and so support the experimental findings rather than theory in the conflict raised earlier on this matter. Ostensibly the dissociation proceeds diabatically on the surface of the initially populated 2A″(1a″ → 2a″) state yielding OH(X2II) + O(1D). 相似文献
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