http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Enrichment of molecular antenna triplets amplifies upconverting nanoparticle emission
Garfield, David J.,Borys, Nicholas J.,Hamed, Samia M.,Torquato, Nicole A.,Tajon, Cheryl A.,Tian, Bining,Shevitski, Brian,Barnard, Edward S.,Suh, Yung Doug,Aloni, Shaul,Neaton, Jeffrey B.,Chan, Emory M Nature Publishing Group UK 2018 Nature photonics Vol.12 No.7
<P>Efficient photon upconversion at low light intensities promises major advances in technologies spanning solar energy harvesting to deep-tissue biophotonics. Here, we discover the critical mechanisms that enable near-infrared dye antennas to significantly enhance performance in lanthanide-doped upconverting nanoparticle (UCNP) systems, and leverage these findings to design dye-UCNP hybrids with a 33,000-fold increase in brightness and a 100-fold increase in efficiency over bare UCNPs. We show that increasing the lanthanide content in the UCNPs shifts the primary energy donor from the dye singlet to its triplet, and the resultant triplet states then mediate energy transfer into the nanocrystals. Time-gated phosphorescence, density functional theory, singlet lifetimes and triplet-quenching experiments support these findings. This interplay between the excited-state populations in organic antennas and the composition of UCNPs presents new design rules that overcome the limitations of previous upconverting materials, enabling performances now relevant for photovoltaics, biophotonics and infrared detection.</P>
Optimized Structures for Photonic Quasicrystals
Rechtsman, Mikael C.,Jeong, Hyeong-Chai,Chaikin, Paul M.,Torquato, Salvatore,Steinhardt, Paul J. American Physical Society 2008 Physical review letters Vol.101 No.7
<P>A photonic quasicrystal consists of two or more dielectric materials arranged in a quasiperiodic pattern with noncrystallographic symmetry that has a photonic band gap. We use a novel method to find the pattern with the widest TM-polarized gap for two-component materials. Patterns are obtained by computing a finite sum of density waves, assigning regions where the sum exceeds a threshold to a material with one dielectric constant, epsilon1, and all other regions to another, epsilon0. Compared to optimized crystals, optimized quasicrystals have larger gaps at low constrasts epsilon1/epsilon0 and have gaps that are much more isotropic for all contrasts. For high contrasts, optimized hexagonal crystals have the largest gaps.</P>
Quality parameters of chicken breast meat affected by carcass scalding conditions
Rosana Aparecida da Silva-Buzanello,Alexia Francielli Schuch,Andre Wilhan Gasparin,Alex Sanches Torquato,Fernando Reinoldo Scremin,Cristiane Canan,Adriana Lourenco Soares 아세아·태평양축산학회 2019 Animal Bioscience Vol.32 No.8
Objective: The influence of broiler carcass scalding conditions on chicken breast meat quality parameters was investigated. Methods: Two hundred and seventy Cobb broiler chickens from 42 to 48 days old were slaughtered according to the standard industry practice and scalded in five temperature/time combinations—T1, 54°C/210 s; T2, 55°C/180 s; T3, 56°C/150 s; T4, 57°C/120 s; T5, 58°C/90 s. Results: Scalding temperature increase resulted in higher values of external and ventral lightness and in protein functionality reduction—determined by emulsification capacity and protein denaturation—in chicken breast fillets 24 h post-mortem. Protein secondary structures had conformational changes, with a decrease of the α-helix and an increase of the β-sheet and β-turn proportions, mainly in T1 and T5 samples, determined by Fourier-transform infrared spectroscopy in an attenuated reflectance mode analysis. The chemical composition, pH, water holding capacity and Warner-Bratzler shear force did not differ among the treatments. In the fatty acid profile, the 18:1n-9 was lower in T5, which suggested that the high scalding-temperature could have caused the lipid oxidation. The values of the polyunsaturated fatty acids (PUFA), such as 22:2, 20:4n-6, and 22:6n-3, were highest in the T5, thus being related to the phospholipid cellular membrane collapse in this experimental condition and subsequent release of these PUFA. Conclusion: Intermediate scalding-parameters avoided the negative changes in the chicken meat quality.