In this work, we utilize the dynamic invariant method to obtain a solution for the time-dependent Schrödinger equation, aiming to explore the quantum theory of a p-form gauge field propagating in ...D-dimensional de Sitter spacetimes. Thus, we present a generalization, through the use of p-form gauge fields, of the quantization procedure for the scalar, electromagnetic, and Kalb–Ramond fields, all of which have been previously studied in the literature. We present an exact solution for the p-form gauge field when D=2(p+1), and we highlight the connection of the p=4 case with the chiral N=2, D=10 superstring model. We could observe particle production for D≠2(p+1) because the solutions are time-dependent. Additionally, observers in an accelerated co-moving reference frame will also experience a thermal bath. This could have significance in the realm of extra-dimensional physics, and presents the intriguing prospect that precise observations of the Cosmic Microwave Background might confirm the presence of additional dimensions.
A series of crystals KxRhO2 (x = 0.72, 0.63, 0.55, 0.39, and 0.24) have been synthesized and their vibrational properties have been studied by first principles calculations, Raman spectroscopy, and ...inelastic neutron scattering. The measured vibrational spectra of KxRhO2 for x = 0.72 and 0.63 are consistent with the theoretical prediction for the stoichiometric KRhO2. For samples with x = 0.55, 0.39 and 0.24, extra vibrational modes have been observed and they are believed to be due to the symmetry reduction and the loss of translational symmetry induced by K disorder. The good agreement was found for the phonon density of states among the Raman spectroscopic observations, inelastic neutron scattering and the first principles calculations, as an evidence for the generation of structure disorder by K deficiency.
In this work, we report the multifunctional character of neodymium-doped LaF3 core/shell nanoparticles. Because of the spectral overlap of the neodymium emission bands with the transparency windows ...of human tissues, these nanoparticles emerge as relevant subtissue optical probes. For neodymium contents optimizing the luminescence brightness of Nd3+:LaF3 nanoparticles, subtissue penetration depths of several millimeters have been demonstrated. At the same time, it has been found that the infrared emission bands of Nd3+:LaF3 nanoparticles show a remarkable thermal sensitivity, so that they can be advantageously used as luminescent nanothermometers for subtissue thermal sensing. This possibility has been demonstrated in this work: Nd3+:LaF3 nanoparticles have been used to provide optical control over subtissue temperature in a single-beam plasmonic-mediated heating experiment. In this experiment, gold nanorods are used as nanoheaters while thermal reading is performed by the Nd3+:LaF3 nanoparticles. The possibility of a real single-beam-controlled subtissue hyperthermia process is, therefore, pointed out.
Neste trabalho apresentamos as soluções analítica e numérica da equação de movimento de uma partícula clássica em um potencial pseudo-harmônico, definido como V(x) = ¹/2kx²+¹/2 a/x². Também ...calculamos a função de partição e obtemos algumas funções termodinâmicas do sistema.
In this work, we report the multifunctional character of neodymium-doped LaF sub(3) core/shell nanoparticles. Because of the spectral overlap of the neodymium emission bands with the transparency ...windows of human tissues, these nanoparticles emerge as relevant subtissue optical probes. For neodymium contents optimizing the luminescence brightness of Nd super(3+):LaF sub(3) nanoparticles, subtissue penetration depths of several millimeters have been demonstrated. At the same time, it has been found that the infrared emission bands of Nd super(3+):LaF sub(3) nanoparticles show a remarkable thermal sensitivity, so that they can be advantageously used as luminescent nanothermometers for subtissue thermal sensing. This possibility has been demonstrated in this work: Nd super(3+):LaF sub(3) nanoparticles have been used to provide optical control over subtissue temperature in a single-beam plasmonic-mediated heating experiment. In this experiment, gold nanorods are used as nanoheaters while thermal reading is performed by the Nd super(3+):LaF sub(3) nanoparticles. The possibility of a real single-beam-controlled subtissue hyperthermia process is, therefore, pointed out.
Neste trabalho estudamos um sistema clássico de dois osciladores harmônicos acoplados com massas (m i), constantes de mola (k i) e parâmetro de acoplamento (κ) dependentes do tempo. Para encontrar as ...soluções das equações de movimento de cada oscilador, usamos uma transformação canônica para reescrever a hamiltoniana do sistema acoplado como a soma das hamiltonianas de dois osciladores harmônicos desacoplados com frequências modificadas e massas unitárias. Analisamos o comportamento de x i,v i = ẋi e do diagrama de fase x i vs.vi para o sistema m1=m2=moeγt e k1=k2=κ=koeγt
In this work we study a coupled system of two classical oscillators with time-dependent masses (m i), spring constants (k i) and coupling parameter (κ). To obtain the solution of the equation of motion for each oscillator, we use a canonical transformation to rewrite the Hamiltonian of the coupled system as the sum of the hamiltonians of two uncoupled harmonic oscillators with modified frequencies and unitary masses. We analyze the behavior of x i,v i = ẋi and the phase diagram x i vs. v i for the system m1=m2=moeγt and k1=k2=κ=koeγt
Neste trabalho calculamos o potencial elétrico para algumas distribuições infinitas de cargas puntiformes. Para cada distribuição discutimos os critérios de convergência das séries obtidas. ...Calculamos também a densidade de carga superficial induzida em um plano condutor infinito "aterrado" e em uma esfera condutora "aterrada" de raio a por uma distribuição infinita de cargas puntiformes com sinais alternados e magnitude que diminui harmonicamente com n (~ q/n)
In this work we obtain the electric potential for some infinite distributions of point charges. The convergence criteria for the resulting series are discussed. We also calculate the surface charge density induced on an infinite grounded conducting plane and on a grounded conducting sphere of radius a by an infinite distribution of point charges with alternate signs and harmonically decreasing magnitude (∼ q/n)
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