7 research outputs found

    Facile generation of L10-FePt nanodot arrays from a nanopatterned metallopolymer blend of iron and platinum homopolymers

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    Hard ferromagnetic (L10 phase) FePt alloy nanoparticles (NPs) with extremely high magnetocrystalline anisotropy are considered to be one of the most promising candidates for the next generation of ultrahigh-density data storage system. The question of how to generate ordered patterns of L1 0-FePt NPs and how to transform the technology for practical applications represents a key current challenge. Here the direct synthesis of L10 phase FePt NPs by pyrolysis of Fe-containing and Pt-containing metallopolymer blend without post-annealing treatment is reported. Rapid single-step fabrication of large-area nanodot arrays (periodicity of 500 nm) of L10-ordered FePt NPs can also be achieved by employing the metallopolymer blend, which possesses excellent solubility in most organic solvents and good solution processability, as the precursor through nanoimprint lithography (NIL). Magnetic force microscopy (MFM) imaging of the nanodot pattern indicates that the patterned L10 phase FePt NPs are capable of exhibiting decent magnetic response, which suggests a great potential to be utilized directly in the fabrication of bit patterned media (BPM) for the next generation of magnetic recording technology. Rapid single-step fabrication of large-area nanodot arrays of L10-FePt nanoparticles (NPs) are achieved by employing a metallopolymer blend of individual Fe- and Pt-containing homopolymers as the precursor through nanoimprint lithography. Imaging of the nanodot pattern indicates that the patterned NPs exhibit a decent magnetic response, which suggests potential to be utilized directly in the fabrication of bit-patterned media for the next generation of magnetic recording technology.Department of Applied Physic

    A polyferroplatinyne precursor for the rapid fabrication of L1 0-FePt-type bit patterned media by nanoimprint lithography

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    A polyferroplatinyne polymer can be patterned on the surface of Si wafer in ordered nanoline or nanodot shapes with PDMS molds through nanoimprint lithography (NIL), and subsequent thermal treatment gives rise to the nanopatterned arrays of L1 0-FePt nanoparticles with the same periodicities. The method offers excellent potential to be utilized in the simple and rapid fabrication of bit patterned media for magnetic data recording. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.link_to_subscribed_fulltex

    Management of child abuse in Hong Kong: Results of a territory-wide interhospital prospective surveillance study

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    Objectives. To study suspected child abuse among children in hospital in terms of clinical characteristics and the outcome of multidisciplinary case conferences. Design. Prospective observational study. Setting. All public hospitals in Hong Kong with a paediatric department. Methods. Anonymous data were prospectively collected from July 1997 to June 1999 using a standard report form for each case of suspected child abuse. The characteristics of the incidents and factors influencing the conclusion at the multidisciplinary case conference were studied. Results. Data for 592 cases of suspected child abuse were evaluated. Two hundred and eighty-seven of the children were boys and 305 were girls. The mean age was 7.3 years (range, 0-16.7 years). Physical abuse, alone or in combination with other forms of maltreatment, accounted for 277 (86.6%) of the 320 substantiated cases. Either, or both, biological parents comprised 71.3% of the perpetrators. Seven (1.2%) children died. Of the 540 children about whom a multidisciplinary case conference was held, abuse was established for 281 (52.0%) children. Abuse was more likely to be established if the victim had been known to a childcare agency (odds ratio=2.2; 95% confidence interval, 1.4-3.5), the abuse was not sexual (odds ratio=2.7; 95% confidence interval, 1.4-5.0), or if the child was seen at a hospital that handled more than 100 cases of suspected abuse during the study period (odds ratio=3.6; 95% confidence interval, 2.4-5.4). Conclusion. Child abuse identified in the hospital setting is predominantly physical in nature and death is not uncommon. Appraisal of suspected child abuse by multidisciplinary case conference appears to be influenced by the region of Hong Kong in which the case was handled.link_to_subscribed_fulltex
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