12,073 research outputs found

    Electroresistance and field effects in epitaxial thin films of Pr 0.7Sr0.3MnO3

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    Highly epitaxial thin films of Pr0.7Sr0.3MnO 3 were grown on (100) SrTiO3 single crystal substrates by laser ablation. Similar to other manganite compounds, these Pr 0.7Sr0.3MnO3 films exhibited remarkable magnetoresistance. Application of electric currents could induce a remarkable reduction in resistivity, demonstrating a strong electroresistance effect. The ratio of the resistance variation, ER=[R(0)-R(I)]/R(I), is about 33% at metal-insulator transition temperature. Using a planar field effect configuration, significant field modulation of the metal-insulator transition was achieved. The observed field effects were discussed based on the strong interactions between carrier spins and localized spins in Mn ions, as well as the percolative mechanism of phase separation. Ā© 2010 The Author(s).published_or_final_versionSpringer Open Choice, 31 May 201

    Advance of molecular marker application in the tobacco research

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    Tobacco (Nicotiana spp.) is one of the most important commercial crops in the world. During the last two decades, molecular markers have entered the scene of genetic improvement in different fields of agricultural research. The principles and characteristics of several molecular markers such as RFLP, RAPD, AFLP, microsatellites and minisatellites applied in tobacco genetics and breeding were reviewed. The application and development of molecular marker in tobacco genetic research was presentedemphatically in the following areas: evolutionary genetics, population genetics and genotyping of cultivars, mapping and tagging of genes, and diversity analysis of germplasm. Finally, the perspective of molecular markerā€™s application in tobacco genetic breeding in the future was discussed

    Width and wavelength-tunable optical pulse train generation based on four-wave mixing in highly nonlinear photonic crystal fiber

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    Author name used in this publication: M. S. DemokanAuthor name used in this publication: H. Y. Tam2005-2006 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    Stable and broad bandwidth multiwavelength fiber ring laser incorporating a highly nonlinear photonic crystal fiber

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    Author name used in this publication: M. S. DemokanAuthor name used in this publication: H. Y. Tam2005-2006 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    Analysis of buck-boost converter inductor loss using a simpleonline B-H curve tracer

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    A simple method to plot online B-H curves and calculate the core loss of the inductor in a conventional buck-boost power converter is developed. In order to obtain a reliable loss data, measurement error and phase shift error are analyzed and then quantified. A new method to minimize measurement error is given. A new core loss model in terms of switching duty cycle is presented. This model predicts variation of core loss of an inductor operating in various conditions in a switching converter. This inductor model can be generalized to inductors in other switching converter topologies.published_or_final_versio

    Growth of long-period gratings in Hā‚‚-loaded fiber after 193-nm UV inscription

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    2000-2001 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    Excitation Spectra And Hard-core Thermodynamics Of Bosonic Atoms In Optical Superlattices

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    A generalized double-well-basis coupled representation is proposed to investigate excitation spectra and thermodynamics of bosonic atoms in double-well optical superlattices. In the hard-core limit and with a filling factor of one, excitations describing the creation of pairs of a doubly occupied state and a simultaneous empty state, and those from a symmetric singly occupied state to an antisymmetric state are carefully analyzed and their excitation spectra are calculated within mean-field theory. Based on the hard-core statistics, the equilibrium properties such as heat capacity and particle populations are studied in detail. The cases with other filling factors are also briefly discussed.published_or_final_versio

    A RAMP marker linked to the tobacco black shank resistant gene

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    Bulk segregant analysis (BSA) and randomly amplified microsatellite polymorphism (RAMP) were employed to analyze F2 individuals of the Yunyan 317ƗHubei 517 to screen and characterize molecularmarkers linked to black shank resistant gene. A total of 800 arbitrary decamer oligonucleotide primerpairs were used for RAMP analysis. Primer pair GT (CA) 4/S89, producing one RAMP marker GT (CA)4/S89550, was tightly linked to the black shank resistant gene. Results of Southern blot suggest that the fragment GT (CA) 4/S89550 was existed in Yunyan 317 and resistant plants, and absent in Hubei 517.Linkage analysis was carried out using marker GT (CA) 4/S89550 on 752 black shank high-resistant individuals of F2 progenies from crossing between Yunyan 317 and Hubei 517. Our results indicated thatthe genetic distances between GT (CA) 4/S89550 and black shank resistant gene was 1.4cM
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