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991.
The purpose of this paper is to determine all commutative hypergroup extensions of a countable discrete commutative hypergroup by a locally compact Abelian group, in terms of second order cohomology of hypergroups, a notion which generalizes the cohomology of groups.  相似文献   
992.
Journal of High Energy Physics - Recently an orthogonal basis of $$ {\mathcal{W}}_N $$ -algebra (AFLT basis) labeled by N-tuple Young diagrams was found in the context of 4D/2D duality. Recursion...  相似文献   
993.
994.
Five new firefly luciferin ( 1 ) analogues were synthesized and their light emission properties were examined. Modifications of the thiazoline moiety in 1 were employed to produce analogues containing acyclic amino acid side chains ( 2 – 4 ) and heterocyclic rings derived from amino acids ( 5 and 6 ) linked to the benzothiazole moiety. Although methyl esters of all of the synthetic derivatives exhibited chemiluminescence activity, only carboluciferin ( 6 ), possessing a pyrroline‐substituted benzothiazole structure, had bioluminescence (BL) activity (λmax=547 nm). Results of bioluminescence studies with AMP‐carboluciferin (AMP=adenosine monophosphate) and AMP‐firefly luciferin showed that the nature of the thiazoline mimicking moiety affected the adenylation step of the luciferin–luciferase reaction required for production of potent BL. In addition, BL of 6 in living mice differed from that of 1 in that its luminescence decay rate was slower.  相似文献   
995.
A versatile phosphorus‐containing π‐conjugated building block, thieno[3,4‐c]phosphole‐4,6‐dione (TPHODO), has been developed. The utility of this simple but hitherto unknown building block has been demonstrated by preparing novel functional organophosphorus compounds and bandgap‐tunable conjugated polymers.  相似文献   
996.
Micro- and nano-fabrications of polystyrene (PS) having the atactic and syndiotactic structures were carried out with direct maskless etching using focused ion beam (FIB). Micro- and nano-scale structures were obtained with selective beam and material conditions avoiding the beam-heating and charge-up effects. The etching rates were different between atactic and syndiotactic PS. The rate of fabrication for syndiotactic PS shows higher than that of atactic one. Moreover, the direct etching was influenced by the molecular weight. The etching rate for the lower molecular weight became the faster. The FIB direct etching proceeds through the two steps (decomposition and desorption (outgas)). Both decomposition and desorption are influenced by both conformation (morphology) and configuration (stereoregularity). Furthermore, the beam profiles and fluence play the important roles to perform the nano-fabrication of PS.  相似文献   
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We study hidden parasupersymmetry structures in purely bosonic quantum mechanics on compact equilateral graphs. We consider a single free spinless particle on the graphs and show that the Huang–Su parasupersymmetry algebra is hidden behind degenerate spectra.  相似文献   
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