180 research outputs found

    Design and Implementation of Reusable Components Using PowerBuilder

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    AbstractComponent technology is a key technology of software reuse. This paper investigates PowerBuilder based technology of software reuse, especially the technology of component design. To build a reusable component, reusable elements in the application system are firstly extracted. The reusable components are then used to form a reusable component library. When designing application system, suitable components are selected from the reusable library and then instantiated. Software system is implemented by composing the instanced components under a reusable framework. Practical results show that the use of reusable components can improve the efficiency of software development

    Giant negative magnetoresistance of spin polarons in magnetic semiconductors–chromium-doped Ti2O3 thin films

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    Epitaxial Cr-doped Ti2O3 films show giant negative magnetoresistance up to –365% at 2 K. The resistivity of the doped samples follows the behavior expected of spin (magnetic) polarons at low temperature. Namely, rho= rho0 exp(T0/T)p, where p = 0.5 in zero field. A large applied field quenches the spin polarons and p is reduced to 0.25 expected for lattice polarons. The formation of spin polarons is an indication of strong exchange coupling between the magnetic ions and holes in the system

    Magnetic and transport properties of NiMnAl thin films

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    The magnetic and transport properties of Ni2MnAl thin films prepared using pulse laser deposition were investigated. It was shown that the films are granular and multiphase. Contrary to the data reported earlier we observe nonmonotonic temperature dependence of resistance with minimum in the vicinity of 100 K for the films deposited on substrates held at 773 K and negative magnetoresistance (MR) values of about 2.5% at 5 K and 1.6% at RT in magnetic field of 50 kOe. These values of MR are the highest reported up to date for Ni2MnAl films. Large negative MR in our films arises from a nonhomogeneous structure and its origin is the same as for granular films

    Magnetic and transport properties of NiMnAl thin films

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    The magnetic and transport properties of Ni2MnAl thin films prepared using pulse laser deposition were investigated. It was shown that the films are granular and multiphase. Contrary to the data reported earlier we observe nonmonotonic temperature dependence of resistance with minimum in the vicinity of 100 K for the films deposited on substrates held at 773 K and negative magnetoresistance (MR) values of about 2.5% at 5 K and 1.6% at RT in magnetic field of 50 kOe. These values of MR are the highest reported up to date for Ni2MnAl films. Large negative MR in our films arises from a nonhomogeneous structure and its origin is the same as for granular films

    Magnetic and transport properties of NiMnAl thin films

    Get PDF
    The magnetic and transport properties of Ni2MnAl thin films prepared using pulse laser deposition were investigated. It was shown that the films are granular and multiphase. Contrary to the data reported earlier we observe nonmonotonic temperature dependence of resistance with minimum in the vicinity of 100 K for the films deposited on substrates held at 773 K and negative magnetoresistance MR values of about 2.5% at 5 K and 1.6% at RT in magnetic field of 50 kOe. These values of MR are the highest reported up to date for Ni2MnAl films. Large negative MR in our films arises from a nonhomogeneous structure and its origin is the same as for granular films. © 2006 American Institute of Physics

    Study on the rare radiative decay Bc→Ds∗γB_c \to D_s^*\gamma in the standard model and multiscale walking technicolor model

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    Applying the perturbative QCD ( PQCD ) method, we study the decay Bc→Ds∗γB_c\rightarrow D_s^*\gamma in the standard model and multiscale walking technicolor model. In the SM, we find that the contribution of weak annihilation is more important than that of the electromagnetic penguin. The presence of Pseudo-Goldstone-Bosons in the MWTCM leads to a large enhancement in the rate of Bc→Ds∗γB_c\rightarrow D_s^*\gamma, but this model is in conflict with the branching ratio of Z→bb‾Z\rightarrow b\overline b ( RbR_b ) and the CLEO data on the branching ratio BR ( b→sγb\rightarrow s\gamma ). If topcolor is further introduced, the calculated results in the topcolor assisted MWTCM can be suppressed and be in agreement with the CLEO data for a certain range of the parameters.Comment: 16 pages, Latex, no macros, 1 figure(in Latex), hard copy is available upon request. to appear in Phys. Rev.
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