976 resultados para deceptive activities
Resumo:
The three-photon absorption (3PA) properties of two thiophene-fluorene derivatives (abbreviated as MOTFTBr and ATFTBr) have been determined by using a Q-switched Nd:YAG laser pumped wish 38ps pulses at 1064nm in DMF. The measured 3PA cross-sections are 152x10(-78)cm(6)s(2) and 139x10(-78)cm(6)s(2), respectively. The optimized structures were obtained by AM1 calculations and the results indicate that these two molecules show nonplanar structures, and attaching different donors has different effects on the molecular structure. The charge density distributions during the excitation were also systematically studied by using AM1 method. In addition, an obvious optical power limiting effect induced by 3PA has been demonstrated for both derivatives.
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311 p.
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Data from the Mexican purse seiner fleet operating in the eastern Tropical Pacific, for the year 1985-1990, are used to show that the fraction of surface schools of yellowfin tuna Thunnus albacares associated with dolphins (Stenella attenuata and others) increases with sea surface temperature. Possible reasons for this correlation are briefly discussed.
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Seaweed production is an important secondary, activity for fishers in eastern Indonesia. In Lombok and Bali, however, it is a major enterprise involving whole village communities in a range of activities from trading to tourism.