180 research outputs found
Ladder operators for subtle hidden shape invariant potentials
Ladder operators can be constructed for all potentials that present the
integrability condition known as shape invariance, satisfied by most of the
exactly solvable potentials. Using the superalgebra of supersymmetric quantum
mechanics we construct the ladder operators for two exactly solvable potentials
that present a subtle hidden shape invariance.Comment: 9 pages, based on the talk given at International Conference Progress
in Supersymmetric Quantum Mechanics (PSQM03), Valladolid, Spain, 15-19 July,
2003, to appear in a Special Issue of J. Phys. A: Math. Ge
Utilization of the wastes of vital activity
The recycling of wastes from the biological complex for use in life-support systems is discussed. Topics include laboratory equipment, heat treatment of waste materials, mineralization of waste products, methods for production of ammonium hydroxide and nitric acid, the extraction of sodium chloride from mineralized products, and the recovery of nutrient substances for plants from urine
Upper critical magnetic field in Ba_0.68K_0.32Fe_2As_2 and Ba(Fe_0.93Co_0.07)_2As_2
We report measurements of the temperature dependence of the radio-frequency
magnetic penetration depth in Ba_0.68K_0.32Fe_2As_2 and
Ba(Fe_0.93Co_0.07)_2As_2 single crystals in pulsed magnetic fields up to 60 T.
From our data, we construct an H-T phase diagram for the inter-plane (H || c)
and in-plane (H || ab) directions for both compounds. For both field
orientations in Ba_0.68K_0.32Fe_2As_2, we find a concave curvature of the
Hc2(T) lines with decreasing anisotropy and saturation towards lower
temperature. Taking into account Pauli spin paramagnetism we can describe
Hc2(T) and its anisotropy. In contrast, we find that Pauli paramagnetic pair
breaking is not essential for Ba(Fe_0.93Co_0.07)_2As_2. For this electron-doped
compound, the data support a Hc2(T) dependence that can be described by the
Werthamer Helfand Hohenberg model for H || ab and a two-gap behavior for H ||
c.Comment: 7 pages, 8 figure
An Algebraic q-Deformed Form for Shape-Invariant Systems
A quantum deformed theory applicable to all shape-invariant bound-state
systems is introduced by defining q-deformed ladder operators. We show these
new ladder operators satisfy new q-deformed commutation relations. In this
context we construct an alternative q-deformed model that preserve the
shape-invariance property presented by primary system. q-deformed
generalizations of Morse, Scarf, and Coulomb potentials are given as examples
Fermi surface and effect of high magnetic fields on the metal–semimetal Peierls-like transition of (TSeT)₂Cl
Resistance measurements in pulsed magnetic fields up to 55 T as well as a first-principles DFT calculation of the Fermi surface for the organic metal (TSeT)₂Cl have been performed to investigate its metal–semimetal phase transition. The results obtained are in line with the imperfect nesting that can be inferred from both the observed
metallic behavior of the resistivity at low temperature and the previously reported Shubnikov–de Haas oscillations due to small carrier pockets. The DFT study points out the possibility that the LUMO bands of the TSeT donor may interact with the HOMO ones and modify the shape of the Fermi surface under pressure
Order of strength exercises on the performance of judo athletes
OBJETIVO: El objetivo fue investigar el efecto del orden distintas de
ejercicios de fuerza para extremidades superiores e inferiores en el rendimiento
específico de judokas junior. MÉTODO: Se divide una muestra de 39 atletas
masculinos en tres grupos: Experimental-EG1; EG2 y Control. Los Grupos
realizaron ejercicios de fuerza máxima y potencia con intensidades del 80-90%
para 12 semanas de intervención. El orden de los ejercicios para el EG1 fue del
de extremidades superiores primero e inferiores después. El EG2 realiza los
mismos ejercicios en secuencia inversa. Se utilizó la Prueba Especial Judo
Fitness (SJFT) para evaluación. RESULTADOS: Los experimentos intra e inter
grupos muestran diferencias (p<0.05) en los derribos-caídas y en el índice SJFT,
con EG2 mostrando mejores resultados. CONCLUSIONES: Las variables de
SJFT tuvieron mejores resultados en el orden de ejercicios seguidos por el EG2OBJECTIVE: To analyze the effect of strength exercises using different orders
for upper and lower limbs on the specific performance of junior judo athletes.
METHODS: 39 male athletes were divided into three groups: experimental-
EG1, experimental-EG2 and control group. Experimental groups performed with
intensities 80-90% of strength and power for 12 weeks. The exercise-order for
EG1 followed an upper to lower limb sequence and EG2 performed the same
exercises in reverse. The Special Judo Fitness Test (SJFT) was used in the
assessment. RESULTS: Experimental intra and inter-groups showed
differences (p<0.05) in the throws-falls and SJFT-index, but the EG2 showed
best results. CONCLUSIONS: The SJFT-variables had better results to
exercises order in EG
Evidence for antiferromagnetism coexisting with charge order in the trilayer cuprate HgBaCaCuO
Multilayered cuprates possess not only the highest superconducting
temperature transition but also offer a unique platform to study disorder-free
CuO planes and the interplay between competing orders with
superconductivity. Here, we study the underdoped trilayer cuprate
HgBaCaCuO and we report the first quantum oscillation
and Hall effect measurements in magnetic field up to 88 T. A careful analysis
of the complex spectra of quantum oscillations strongly supports the
coexistence of an antiferromagnetic order in the inner plane and a charge order
in the outer planes. The presence of an ordered antiferromagnetic metallic
state that extends deep in the superconducting phase is a key ingredient that
supports magnetically mediated pairing interaction in cuprates.Comment: 6+5 pages, 4+6 figure
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