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121.
Piotr Bojarski Leszek Kulak Czeslaw Bojarski Alfons Kawski 《Journal of fluorescence》1995,5(4):307-319
High-accuracy Monte Carlo simulations of the time-dependent excitation probabilityG
s
(t) and steady-state emission anisotropyr
M
/r
0M
for one-component three-dimensional systems were performed. It was found that the values ofr
M
/r
0M
obtained for the averaged orientation factor
only slightly overrate those obtained for the real values of the orientation factor
ik
2
. This result is essentially different from that previously reported. Simulation results were compared with the probability coursesG
s
(t) andR(t) obtained within the frameworks of diagrammatic and two-particle Huber models, respectively. The results turned out to be in good agreement withR(t) but deviated visibly fromG
s
(t) at long times and/or high concentrations. Emission anisotropy measurements on glycerolic solutions of Na-fluorescein and rhodamine 6G were carried out at different excitation wavelengths. Very good agreement between the experimental data and the theory was found, with ex0-0 for concentrations not exceeding 3.5·10–2 and 7.5·10–3
M in the case of Na-fluorescein and rhodamine 6G, respectively. Up to these concentrations, the solutions investigated can be treated as one-component systems. The discrepancies observed at higher concentrations are caused by the presence of dimers. It was found that for
ex
<0-0 (Stokes excitation) the experimental emission anisotropies are lower than predicted by the theory. However, upon anti-Stokes excitation (ex>0-0), they lie higher than the respective theoretical values. Such a dispersive character of the energy migration can be explained qualitatively by the presence of fluorescent centers with 0-0 transitions differing from the mean at 0-0. 相似文献
122.
123.
Natural (?)-menthol was applied to construction of mono-N-tosylated-1,2-diamine derivatives. The O-tosylation and elimination of the tosylate of the menthol intermediate led to trans-p-menth-2-ene. The unsaturated menth-2-ene was next transformed into a mixture of N-tosylaziridines, which upon reaction with sodium azide gave four isomeric azides. The reduction of the formed tosylazides on Pd/C gave new chiral mono-N-tosylated-1,2-diamines, which were used as ligands in the asymmetric transfer hydrogenation protocol on aromatic ketones and endocyclic imine. 相似文献
124.
125.
126.
We consider an abstract first-order evolutionary inclusion in a reflexive Banach space. The inclusion contains the sum of L-pseudomonotone operator and a maximal monotone operator. We provide an existence theorem which is a generalization of former results known in the literature. Next, we apply our result to the case of nonlinear variational–hemivariational inequalities considered in the setting of an evolution triple of spaces. We specify the multivalued operators in the problem and obtain existence results for several classes of variational–hemivariational inequality problems. Finally, we illustrate our existence result and treat a class of quasilinear parabolic problems under nonmonotone and multivalued flux boundary conditions. 相似文献
127.
Leszek Zalewski Dr. Michael Wykes Sergio Brovelli Dr. Massimo Bonini Dr. Thomas Breiner Dr. Marcel Kastler Dr. Florian Dötz Dr. David Beljonne Dr. Harry L. Anderson Prof. Franco Cacialli Prof. Paolo Samorì Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(13):3933-3941
A dithiophene rotaxane 1 ?β‐CD and its shape‐persistent corresponding dumbbell 1 were synthesized and fully characterized. 2D NOESY experiments, supported by molecular dynamics calculations, revealed a very mobile macrocycle (β‐CD). Steady‐state and time‐resolved photoluminescence experiments in solution were employed to elucidate the excited‐state dynamics for both systems and to explore the effect of cyclodextrin encapsulation. The photoluminescence (PL) spectrum of 1 ?β‐CD was found to be blueshifted with respect to the dumbbell 1 (2.81 and 2.78 eV, respectively). Additionally, in contrast to previous observations, neither PL spectra nor the decay kinetics of both threaded and unthreaded systems showed changes upon increasing the concentration or changing the polarity of the solutions, thereby providing evidence for a lack of tendency toward aggregation of the unthreaded backbone. 相似文献
128.
Hoffmann M Eitner K von Grotthuss M Rychlewski L Banachowicz E Grabarkiewicz T Szkoda T Kolinski A 《Journal of computer-aided molecular design》2006,20(5):305-319
The modeling of the severe acute respiratory syndrome coronavirus helicase ATPase catalytic domain was performed using the protein structure prediction Meta Server and the 3D Jury method for model selection, which resulted in the identification of 1JPR, 1UAA and 1W36 PDB structures as suitable templates for creating a full atom 3D model. This model was further utilized to design small molecules that are expected to block an ATPase catalytic pocket thus inhibit the enzymatic activity. Binding sites for various functional groups were identified in a series of molecular dynamics calculation. Their positions in the catalytic pocket were used as constraints in the Cambridge structural database search for molecules having the pharmacophores that interacted most strongly with the enzyme in a desired position. The subsequent MD simulations followed by calculations of binding energies of the designed molecules were compared to ATP identifying the most successful candidates, for likely inhibitors—molecules possessing two phosphonic acid moieties at distal ends of the molecule. 相似文献
129.
130.
Leszek Pia?tkiewicz 《Topology and its Applications》2010,157(16):2555-2561
The Banach-Mazur game as well as the strong Choquet game are investigated on the Wijsman hyperspace from the nonempty player's (i.e. α's) perspective. For the strong Choquet game we show that if X is a locally separable metrizable space, then α has a (stationary) winning strategy on X iff it has a (stationary) winning strategy on the Wijsman hyperspace for each compatible metric on X. The analogous result for the Banach-Mazur game does not hold, not even if X is separable, as we show that α may have a (stationary) winning strategy on the Wijsman hyperspace for each compatible metric on X, and not have one on X. We also show that there exists a separable 1st category metric space such that α has a (stationary) winning strategy on its Wijsman hyperspace. This answers a question of Cao and Junnila (2010) [6]. 相似文献