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11.
Surya Prakash Singh CH Pavan Kumar G. D. Sharma J. A. Mikroyannidis Manjeet Singh Rajnish Kurchania 《Journal of Polymer Science.Polymer Physics》2012,50(23):1612-1618
Power conversion efficiency (PCE) of phenylenevinylene‐based copolymer with BF2 azopyrrole complex (PB)/modified PC70BM, that is, CN‐PC70BM bulk heterojunction solar cells improves from 2.16 to 4.90% using a processing additive and drying condition. The results demonstrate that a processing additive and drying condition provides an effective means to control both the surface roughness and finer interpenetrating networks to enhance the exciton dissociation into free charge carriers, charge transportation, and collection. Taking into the account of simple device fabrication process without thermal annealing, the PCE of the polymer solar cell can further improved by chloronapthalene (CN) additive under the fast drying condition. The average carrier lifetimes extracted from the impedance spectra and found to correlate with measured PCEs. At short circuit conditions and illumination, the average charge carrier lifetime was found vary from 16.8 to 32 μs with power conversion efficiencies ranging from 3.0 to 4.9%. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012 相似文献
12.
Photodynamic Therapy Efficacy Enhanced by Dynamics: The Role of Charge Transfer and Photostability in the Selection of Photosensitizers
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Prof. Luis G. Arnaut Prof. Mariette M. Pereira Dr. Janusz M. Dąbrowski Elsa F. F. Silva Dr. Fábio A. Schaberle Dr. Artur R. Abreu Luís B. Rocha Dr. Madalina M. Barsan Prof. Krystyna Urbańska Prof. Grażyna Stochel Prof. Christopher M. A. Brett 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(18):5346-5357
Progress in the photodynamic therapy (PDT) of cancer should benefit from a rationale to predict the most efficient of a series of photosensitizers that strongly absorb light in the phototherapeutic window (650–800 nm) and efficiently generate reactive oxygen species (ROS=singlet oxygen and oxygen‐centered radicals). We show that the ratios between the triplet photosensitizer–O2 interaction rate constant (kD) and the photosensitizer decomposition rate constant (kd), kD/kd, determine the relative photodynamic activities of photosensitizers against various cancer cells. The same efficacy trend is observed in vivo with DBA/2 mice bearing S91 melanoma tumors. The PDT efficacy intimately depends on the dynamics of photosensitizer–oxygen interactions: charge transfer to molecular oxygen with generation of both singlet oxygen and superoxide ion (high kD) must be tempered by photostability (low kd). These properties depend on the oxidation potential of the photosensitizer and are suitably combined in a new fluorinated sulfonamide bacteriochlorin, motivated by the rationale. 相似文献
13.
Yuri A. de Oliveira Só Mônica de Abreu Silva Fernando M. Carvalho Alessandra S. Kiametis Ricardo Gargano 《International journal of quantum chemistry》2020,120(11):e26194
Oxidative stress is an imbalance between the production of free radicals and the antioxidant defenses of the organism. Heart diseases, anemia, inflammation, and neurodegenerative disorders have been associated with this biological condition. Trolox is a notable antioxidant drug similar to vitamin E, and it is used to decrease the oxidative stress or repair the damage caused by it. In this work, the virtual screening technique is applied to identify compounds with antioxidant activities similar to Trolox. The antioxidant activity of these compounds was assessments by the mechanisms of hydrogen atom transfer and single electron transfer. Properties such as bond dissociation enthalpy, adiabatic ionization potential, Gibbs free reaction energy, spin density, highest occupied molecular orbital (HOMO), and GAP (HOMO-LUMO) energies, obtained from the DFT approach, point out to the predominance of the HAT mechanism for the antioxidant action of these compounds. The obtained results contribute to a better understanding of the chemical and physical properties responsible for antioxidant activity and the design of new antioxidant agents. 相似文献
14.
Langone Marta A. P. De Abreu Melissa E. Rezende Michelle J. C. Sant’Anna Geraldo L. 《Applied biochemistry and biotechnology》2002,98(1-9):987-996
The synthesis of monocaprin, monolaurin, and monomyristin in a solvent-free system was conducted by mixing a commercial immobilized
lipase with the organic reactants (glycerol and fatty acids) in a 20-mL batch reactor with constant stirring. The effects
of temperature, fatty acid/glycerol molar ratio, and enzyme concentration on the reaction conversion were determined. The
addition of molecular sieves in the assays of monomyristin synthesis was also evaluated. The reactions were carried out for
5 to 6 h and the nonpolar phase was analyzed by gas chromatography. The best results in terms of selectivity and conversion
(defined as the percentage of fatty acid consumed) were achieved when the stoichiometric amount of reagents (molar ratio=1)
and 9% (w/w) commercial enzyme were used and the reaction was performed at 60°C. The addition of molecular sieves did not
improve the synthesis of monomyristin. Conversions as high as 80%, with monoglycerides being the major products, were attained.
After 5 h of reaction, the concentration of monoglyceride was about twice that of diglyceride, and only trace amounts of triglyceride
were found. The results illustrate the technical possibility of producing medium chain monoglycerides in a solvent-free medium
using a simple batch reactor. 相似文献
15.
G. Spavieri V. Guerra R. De Abreu G. T. Gillies 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,47(3):457-463
Propagation of Aharonov-Bohm matter waves and light waves in moving media is
characterized by the interaction electromagnetic momentum. Thus, recent
models of light propagation in moving rarefied media justify and call for an optical experiment of the Mascart-Jamin type,
capable of testing the
modern interpretations of ether drift experiments. 相似文献
16.
Properties associated with the infrared, Rayleigh, and Raman spectra of the CO(3) molecule are calculated by the Hartree-Fock and M?ller-Plesset perturbation theory methods. Vibrational frequencies and infrared activities are found to be in agreement with the experiment and previous calculations. The values obtained for the Raman spectrum show a very sensitive dependence to the treatment of electron correlation. The OCO wag normal mode, unobserved in the IR experiment, is predicted to have a very small Raman scattering activity. Copyright 2000 Academic Press. 相似文献
17.
In a recent article [M. Consoli, E. Costanzo, Phys. Lett. A 333 (2004) 355], M. Consoli and E. Costanzo have investigated classical and modern aether drift experiments and explored the narrow window for detection of a preferred reference frame. This Letter proposes an easy to perform variant of Fizeau's experiment, which may confirm or deny Consoli–Costanzo's claims. 相似文献
18.
J. Dorenbosch F. Udo J. V. Allaby U. Amaldi G. Barbiellini M. Baubillier F. Bergsma A. Capone W. Flegel F. Grancagnolo M. Jonker L. Lanceri M. Metcalf C. Nieuwenhuis J. Panman R. Plunkett C. Santoni K. Winter I. Abt F. W. Büsser H. Daumann P. D. Gall T. Hebbeker F. Niebergall P. Stähelin P. Gorbunov E. Grigoriev V. Kaftanov V. Khovansky A. Rosanov A. Baroncelli L. Barone B. Borgia C. Bosio M. Diemoz U. Dore F. Ferroni E. Longo L. Luminari P. Monacelli S. Morganti F. de Notaristefani L. Tortora V. Valente CHARM Collaboration 《Zeitschrift fur Physik C Particles and Fields》1989,41(4):567-589
A determination of sin2 θ w based on measurements of elastic scattering of muon-neutrinos and muon-anti-neutrinos on atomic electrons is described. These purely leptonic processes were studied using the CHARM calorimeter exposed to neutrino and antineutrino wide-band beams at the CERN super proton synchrotron. A total of 83±16 neutrino-electron and 112±21 antineutrino-electron events have been detected. From the measurement of the ratio of muon-neutrino and muon-antineutrino cross-sections a value of sin2 θ w =0.211±0.037 was obtained. 相似文献
19.
P. Abreu et al. 《The European Physical Journal C - Particles and Fields》1999,11(3):383-407
The data collected with the DELPHI detector at centre-of-mass energies between 130 and 172 GeV, during LEP operation in 1995
and 1996, have been used to determine the hadronic and leptonic cross-sections and leptonic forward–backward asymmetries.
In addition, the cross-section ratios and forward–backward asymmetries for flavour-tagged samples of light (uds), c and b
quarks have been measured. No significant deviations from the Standard Model expectations are found. The results are interpreted
by performing S-matrix fits to these data and to the data collected previously at the energies near the resonance peak (88-93 GeV). The results are also interpreted in terms of physics beyond the Standard Model: contact interactions,
R-parity violating SUSY particle exchange and of possible Z bosons.
Received: 9 February 1999 / Published online: 14 October 1999 相似文献
20.