960 resultados para Succession of States


Relevância:

100.00% 100.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Space-charge-limited currents measurements have been carried out on undoped amorphous poly p-phenylene sulfide. The scaling law is checked for different samples with varying thickness, and J-V data analyzed. The position of the quasi-Fermi level and the density of states was obtained.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The Gel'fand-Levitan formalism is used to study how a selected set of bound states can be eliminated from the spectrum of the Coulomb potential and also how to construct a bound state in the Coulomb continuum. It is demonstrated that a sizeable quantum well can be produced by deleting a large number of levels from the s spectral series and the edge of the Coulomb potential alone can support the von Neumann-Wigner states in the continuum. © 1998 Elsevier Science B.V.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Includes bibliography

Relevância:

100.00% 100.00%

Publicador:

Resumo:

We theoretically investigate the local density of states (LDOS) probed by an STM tip of ferromagnetic metals hosting a single adatom and a subsurface impurity. We model the system via the two-impurity Anderson Hamiltonian. By using the equation of motion with the relevant Green's functions, we derive analytical expressions for the LDOS of two host types: a surface and a quantum wire. The LDOS reveals Friedel-like oscillations and Fano interference as a function of the STM tip position. These oscillations strongly depend on the host dimension. Interestingly, we find that the spin-dependent Fermi wave numbers of the hosts give rise to spin-polarized quantum beats in the LDOS. Although the LDOS for the metallic surface shows a damped beating pattern, it exhibits the opposite behavior in the quantum wire. Due to this absence of damping, the wire operates as a spatially resolved spin filter with a high efficiency. © 2013 American Physical Society.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

In this work, we investigate theoretically the spin-resolved local density of states (SR-LDOS) of a ferromagnetic (FM) island hybridized with an adatom, which is described by the Single Impurity Anderson Model (SIAM). Our results are comparable with Scanning Tunneling Microscope (STM) experimental data. © 2012 Springer Science+Business Media, LLC.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

In a finite size bag like picture consisting of quarks (2 flavour) and gluons with SU(3) colour singlet restriction on the partition function and the chemical potential μ ≠ 0 with the constraint that the baryon number b = 0 and b = 1 for mesons and baryons, respectively we find a very good agreement with baryon density of states upto 2 GeV and with mesonic ones upto 1.3 GeV. Similar to a hadron-scale string theory our calculation also suggests that beyond 1.3 GeV there should exist exotic mesons.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The metallic carbides exhibit many novel prototypes of crystalline structure. Among these compounds Th2NiC2 was reported in 1991 as a new carbide which crystallizes in the U2IrC2 prototype structure. In this work we report a reinvestigation of the synthesis of this compound. We find that Th2NiC2 is a new superconductor. Our results suggest that this phase is stable only at high temperatures in the system Th-Ni-C. The substitution of Th by Sc stabilizes the phase and improves the superconducting properties. The highest superconducting critical temperature occurs at 11.2 K with nominal composition Th1.8Sc0.2NiC2. The electronic coefficient determined by specific heat measurements is close to zero. This unusual result can be explained by covalent bonding in the compound.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Polarized magnetophotoluminescence is employed to study the energies and occupancies of four lowest Landau levels in a couple quantum Hall GaAs/AlGaAs double quantum well. As a result, a magnetic field-induced redistribution of charge over the Landau levels manifesting to the continuous formation of the charge density wave and direct evidence for the symmetric-antisymmetric gap shrinkage at v = 3 are found. The observed interlayer charge exchange causes depolarization of the ferromagnetic ground state.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Statement of the problem and public health significance. Hospitals were designed to be a safe haven and respite from disease and illness. However, a large body of evidence points to preventable errors in hospitals as the eighth leading cause of death among Americans. Twelve percent of Americans, or over 33.8 million people, are hospitalized each year. This population represents a significant portion of at risk citizens exposed to hospital medical errors. Since the number of annual deaths due to hospital medical errors is estimated to exceed 44,000, the magnitude of this tragedy makes it a significant public health problem. ^ Specific aims. The specific aims of this study were threefold. First, this study aimed to analyze the state of the states' mandatory hospital medical error reporting six years after the release of the influential IOM report, "To Err is Human." The second aim was to identify barriers to reporting of medical errors by hospital personnel. The third aim was to identify hospital safety measures implemented to reduce medical errors and enhance patient safety. ^ Methods. A descriptive, longitudinal, retrospective design was used to address the first stated objective. The study data came from the twenty-one states with mandatory hospital reporting programs which report aggregate hospital error data that is accessible to the public by way of states' websites. The data analysis included calculations of expected number of medical errors for each state according to IOM rates. Where possible, a comparison was made between state reported data and the calculated IOM expected number of errors. A literature review was performed to achieve the second study aim, identifying barriers to reporting medical errors. The final aim was accomplished by telephone interviews of principal patient safety/quality officers from five Texas hospitals with more than 700 beds. ^ Results. The state medical error data suggests vast underreporting of hospital medical errors to the states. The telephone interviews suggest that hospitals are working at reducing medical errors and creating safer environments for patients. The literature review suggests the underreporting of medical errors at the state level stems from underreporting of errors at the delivery level. ^