At the second order Douglas–Kroll–Hess（DKH2） level, the B3 PW91 functional in conjunction with the relativistic all-electron basis set of valence triple zeta quality plus polarization functions are employed to com...At the second order Douglas–Kroll–Hess（DKH2） level, the B3 PW91 functional in conjunction with the relativistic all-electron basis set of valence triple zeta quality plus polarization functions are employed to compute bond lengths, dissociation energies, vertical ionization potentials, and the highest occupied molecular orbital-lowest unoccupied molecular orbital energy gaps of the small iridium clusters（Irn, n≤8）. These results are compared with the experimental and theoretical data available in the literature. Our results confirm the theoretical predictions made by Feng et al. about the catalytic activities of the Ir4 and Ir6 clusters. From the optimized geometries, DKH2 calculations of static electric mean dipole polarizabilities and polarizability anisotropies are also carried out. It is the first time that the polarizabilities of small iridium clusters have been studied. For n≤4, the mean dipole polarizabilities per atom present an odd–even oscillatory behavior,whereas from Ir5 to Ir8, they decrease with the cluster size increasing. The dependence of the polarizability anisotropy on the structure symmetry of the iridium cluster is verified.展开更多
An action of general form is proposed for a Universe containing matter, radiation and dark energy. The latter is interpreted as a tachyon field non-minimally coupled to the scalar curvature. The Palatini approach is u...An action of general form is proposed for a Universe containing matter, radiation and dark energy. The latter is interpreted as a tachyon field non-minimally coupled to the scalar curvature. The Palatini approach is used when varying the action so the connection is given by a more generic form. Both the self-interaction potential and the non-minimally coupling function are obtained by constraining the system to present invariability under global point transformation of the fields （Noether Symmetry）. The only possible solution is shown to be that of minimal coupling and constant potential （Chaplygin gas）. The behavior of the dynamical properties of the system is compared to recent observational data, which infers that the tachyon field must indeed be dynamical.展开更多
We consider a three-dimensional generalization of the two-dimensional Henon map. We first investigate the emergence of quasiperiodic states, as a result of Naimark-Sacker bifurcations of period-1 and period-2 orbits. ...We consider a three-dimensional generalization of the two-dimensional Henon map. We first investigate the emergence of quasiperiodic states, as a result of Naimark-Sacker bifurcations of period-1 and period-2 orbits. Secondly we investigate the disappearance of the resonance torus in the transition from quasiperiodieity to chaos.展开更多
We report the preparation of poly(3,4-ethylene dioxythiophene)(PEDOT)-modified polyvinylidene fluoride electrospun fibers and their use as a novel adsorbent material for the removal of the anionic dye Methyl Orange(MO...We report the preparation of poly(3,4-ethylene dioxythiophene)(PEDOT)-modified polyvinylidene fluoride electrospun fibers and their use as a novel adsorbent material for the removal of the anionic dye Methyl Orange(MO)from aqueous media.This novel adsorbent material can be used to selectively remove MO on a wide p H range(3.0-10.0),with a maximum capacity of 143.8 mg/g at p H 3.0.When used in a recirculating filtration system,the maximum absorption capacity was reached in a shorter time(20 min)than that observed for batch mode experiments(360 min).Based on the analyses of the kinetics and adsorption isotherm data,one can conclude that the predominant mechanism of interaction between the membrane and the dissolved dye molecules is electrostatic.Besides,considering the estimated values for the Gibbs energy,and entropy and enthalpy changes,it was established that the adsorption process is spontaneous and occurs in an endothermic manner.The good mechanical and environmental stability of these membranes allowed their use in at least 20 consecutive adsorption/desorption cycles,without significant loss of their characteristics.We suggest that the physical-chemical characteristics of PEDOT make these hybrid mats a promising adsorbent material for use in water remediation protocols and effluent treatment systems.展开更多
There has been a growing interest in disordered optical media in recent years due to their potential applications in solar collectors, random lasers, light confinement, and other advanced photonic functions. This pape...There has been a growing interest in disordered optical media in recent years due to their potential applications in solar collectors, random lasers, light confinement, and other advanced photonic functions. This paper studies the transport of light for different incidence angles in a strongly disordered optical medium composed of core-shell TiO_2@Silica nanoparticles suspended in an ethanol solution. A decrease of optical conductance and an increase of absorption near the input border are reported when the incidence angle increases. The specular reflection, measured for the photons that enter the sample, is lower than the effective internal reflection undergone by the coherently backscattered photons in the exact opposite direction, indicating a nonreciprocal propagation of light.This study represents a novel approach in order to understand the complex physics involved at the phase transition to localization.展开更多
We study the sound perturbation of a rotating acoustic black hole in the presence of a disclination. The radial part of the massless Klein-Gordon equation is written into a Heun form, and its analytical solution is ob...We study the sound perturbation of a rotating acoustic black hole in the presence of a disclination. The radial part of the massless Klein-Gordon equation is written into a Heun form, and its analytical solution is obtained. These solutions have an explicit dependence on the parameter of the disclination. We obtain the exact Hawking-Unruh radiation spectrum.展开更多
The efficacy of photodynamic treatments of tumors can be significantly improved by using a new generation of nanoparticles that take advantage of the unique properties of the tumor microenvironment.
In this work we consider black hole solutions to Einstein’s theory coupled to a nonlinear powerlaw electromagnetic field with a fixed exponent value.We study the extended phase space thermodynamics in canonical and g...In this work we consider black hole solutions to Einstein’s theory coupled to a nonlinear powerlaw electromagnetic field with a fixed exponent value.We study the extended phase space thermodynamics in canonical and grand canonical ensembles,where the varying cosmological constant plays the role of an effective thermodynamic pressure.We examine thermodynamical phase transitions in such black holes and find that both first-and second-order phase transitions can occur in the canonical ensemble while,for the grand canonical ensemble,Hawking-Page and second-order phase transitions are allowed.展开更多
Using local central Yukawa-type Malfliet-Tjon interactions reproducing the low-energy parameters and phase shifts of the nn system, and the latest updates of the nΛ and ΛΛ Nijmegen ESC08c potentials, we study the p...Using local central Yukawa-type Malfliet-Tjon interactions reproducing the low-energy parameters and phase shifts of the nn system, and the latest updates of the nΛ and ΛΛ Nijmegen ESC08c potentials, we study the possible existence of a ^4 ΛΛn bound state. Our results indicate that the ^4 ΛΛn is unbound, being just above threshold.We discuss the role played by the -1S0 nn repulsive term of the Yukawa-type Malfliet-Tjon interaction.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 60576016, 10774013, 10804006 and 10434030 （key project）, the National High-Tech Research and Development Program of China under Grant No 2006AA03Z0412, the Natural Science Foundation of Beijing under Grant No 2073030, the National Basic Research Program of China under Grant No 2003CB314707, and Beijing Jiao Tong University under Grants Nos 2005SM057, 2006XM043 and 141028522.
文摘与不同的钒集中做的 ZnO 电影被反应磁控管用一个锌目标劈啪作响与钒做了的 dc 扔到玻璃底层上。钒集中被精力检验散光谱学(版本) 和在 ZnO 薄电影的钒的费用状态被 X 光光电子描绘光谱学。X 光衍射(XRD ) 的结果证明所有这些电影有 wurtzite 结构并且主要在 c 轴取向成长。在扔的电影的谷物尺寸和剩余压力被适合 XRD 结果估计。这些电影的光性质被测量发射度学习。光常数(折射索引和扑灭系数) 和电影厚度被适合发射度获得。所有结果与做钒在关系被讨论。
基金supported by the CNPq,CAPES,and FAPES(Brazilian Agencies)
文摘At the second order Douglas–Kroll–Hess（DKH2） level, the B3 PW91 functional in conjunction with the relativistic all-electron basis set of valence triple zeta quality plus polarization functions are employed to compute bond lengths, dissociation energies, vertical ionization potentials, and the highest occupied molecular orbital-lowest unoccupied molecular orbital energy gaps of the small iridium clusters（Irn, n≤8）. These results are compared with the experimental and theoretical data available in the literature. Our results confirm the theoretical predictions made by Feng et al. about the catalytic activities of the Ir4 and Ir6 clusters. From the optimized geometries, DKH2 calculations of static electric mean dipole polarizabilities and polarizability anisotropies are also carried out. It is the first time that the polarizabilities of small iridium clusters have been studied. For n≤4, the mean dipole polarizabilities per atom present an odd–even oscillatory behavior,whereas from Ir5 to Ir8, they decrease with the cluster size increasing. The dependence of the polarizability anisotropy on the structure symmetry of the iridium cluster is verified.
基金CNPq for the financial support that allowed this work to be done
文摘An action of general form is proposed for a Universe containing matter, radiation and dark energy. The latter is interpreted as a tachyon field non-minimally coupled to the scalar curvature. The Palatini approach is used when varying the action so the connection is given by a more generic form. Both the self-interaction potential and the non-minimally coupling function are obtained by constraining the system to present invariability under global point transformation of the fields （Noether Symmetry）. The only possible solution is shown to be that of minimal coupling and constant potential （Chaplygin gas）. The behavior of the dynamical properties of the system is compared to recent observational data, which infers that the tachyon field must indeed be dynamical.
文摘We consider a three-dimensional generalization of the two-dimensional Henon map. We first investigate the emergence of quasiperiodic states, as a result of Naimark-Sacker bifurcations of period-1 and period-2 orbits. Secondly we investigate the disappearance of the resonance torus in the transition from quasiperiodieity to chaos.
文摘We report the preparation of poly(3,4-ethylene dioxythiophene)(PEDOT)-modified polyvinylidene fluoride electrospun fibers and their use as a novel adsorbent material for the removal of the anionic dye Methyl Orange(MO)from aqueous media.This novel adsorbent material can be used to selectively remove MO on a wide p H range(3.0-10.0),with a maximum capacity of 143.8 mg/g at p H 3.0.When used in a recirculating filtration system,the maximum absorption capacity was reached in a shorter time(20 min)than that observed for batch mode experiments(360 min).Based on the analyses of the kinetics and adsorption isotherm data,one can conclude that the predominant mechanism of interaction between the membrane and the dissolved dye molecules is electrostatic.Besides,considering the estimated values for the Gibbs energy,and entropy and enthalpy changes,it was established that the adsorption process is spontaneous and occurs in an endothermic manner.The good mechanical and environmental stability of these membranes allowed their use in at least 20 consecutive adsorption/desorption cycles,without significant loss of their characteristics.We suggest that the physical-chemical characteristics of PEDOT make these hybrid mats a promising adsorbent material for use in water remediation protocols and effluent treatment systems.
基金Fundacao De AmparoaPesquisa Do Estado De Sao Paulo(FAPESP)(2017/05854-9,2017/10765-5,2012/10127-5)Instituto Nacional de Ciencia e Tecnologia de Engenharia de Superficies(INCT/INES)(465423/2014-0)
文摘There has been a growing interest in disordered optical media in recent years due to their potential applications in solar collectors, random lasers, light confinement, and other advanced photonic functions. This paper studies the transport of light for different incidence angles in a strongly disordered optical medium composed of core-shell TiO_2@Silica nanoparticles suspended in an ethanol solution. A decrease of optical conductance and an increase of absorption near the input border are reported when the incidence angle increases. The specular reflection, measured for the photons that enter the sample, is lower than the effective internal reflection undergone by the coherently backscattered photons in the exact opposite direction, indicating a nonreciprocal propagation of light.This study represents a novel approach in order to understand the complex physics involved at the phase transition to localization.
基金Supported by Conselho Nacional de Desenvolvimento Científico e Tecnológico(140612/2014-9)
文摘We study the sound perturbation of a rotating acoustic black hole in the presence of a disclination. The radial part of the massless Klein-Gordon equation is written into a Heun form, and its analytical solution is obtained. These solutions have an explicit dependence on the parameter of the disclination. We obtain the exact Hawking-Unruh radiation spectrum.
基金the Ministerio de Ciencia e Innovacion de Espana under project PID2019-106211RB-100E.X.is grateful for a Juan de la Cierva Formaci6n scholarship(FJC2018-036734-I).
文摘The efficacy of photodynamic treatments of tumors can be significantly improved by using a new generation of nanoparticles that take advantage of the unique properties of the tumor microenvironment.
基金supported by ANID Chile through FONDECYT Grant No.1210635(J S)support from the Dirección de Investigación y Desarrollo de la Universidad de La Serena,Grant No.PR18142supported in part by NNSFC under Grant No.12075202。
文摘In this work we consider black hole solutions to Einstein’s theory coupled to a nonlinear powerlaw electromagnetic field with a fixed exponent value.We study the extended phase space thermodynamics in canonical and grand canonical ensembles,where the varying cosmological constant plays the role of an effective thermodynamic pressure.We examine thermodynamical phase transitions in such black holes and find that both first-and second-order phase transitions can occur in the canonical ensemble while,for the grand canonical ensemble,Hawking-Page and second-order phase transitions are allowed.
基金Supported by COFAA-IPN(Mxico),Ministerio de Economía,Industria y Competitividad and EU FEDER(FPA2013-47443,FPA2015-69714-REDT,FPA2016-77177)Junta de Castilla y Len(SA041U16)Generalitat Valenciana Prometeo II/2014/066
文摘Using local central Yukawa-type Malfliet-Tjon interactions reproducing the low-energy parameters and phase shifts of the nn system, and the latest updates of the nΛ and ΛΛ Nijmegen ESC08c potentials, we study the possible existence of a ^4 ΛΛn bound state. Our results indicate that the ^4 ΛΛn is unbound, being just above threshold.We discuss the role played by the -1S0 nn repulsive term of the Yukawa-type Malfliet-Tjon interaction.
