Magneto-optical characteristics of magnetic nanowire arrays in anodic aluminium oxide templates

Nanocomposite films consisting of regularly ordered iron nanowires embedded in anodic aluminum oxide templates have been fabricated and their magneto-optical properties studied by determining the four Stokes parameters of the transmitted laser beam (λ=670 nm), originally linearly polarized and at normal incidence to the film surfaces. The results of the nanowire arrays are found to be considerably different from that of bulk iron. While an increase in diameter of the nanowire leads to a substantial increase in the values of the Faraday rotation angles per unit length at a fixed value of the magnetic fields, they are substantially less than that of bulk iron, indicating that the effective media theory may not be directly applicable

Phase-locking of multiple magnetic droplets by a microwave magnetic field

Manipulating dissipative magnetic droplet is of great interest for both the fundamental and technological reasons due to its potential applications in the high frequency spin-torque nano-oscillators. In this paper, a magnetic droplet pair localized in two identical or non-identical nano-contacts in a magnetic thin film with perpendicular anisotropy can phase-lock into a single resonance state by using an oscillating microwave magnetic field. This resonance state is a little away from the intrinsic precession frequency of the magnetic droplets. We found that the phase-locking frequency range increases with the increase of the microwave field strength. Furthermore, multiple droplets with a random initial phase can also be synchronized by a microwave field.published_or_final_versio

A hybrid algorithm for spatial and wavelet domain image restoration

The recent algorithm ForWaRD based on the two steps: (i) the Fourier domain deblurring and (ii) wavelet domain denoising, shows better restoration results than those using traditional image restoration methods. In this paper, we study other deblurring schemes in ForWaRD and demonstrate such two-step approach is effective for image restoration.published_or_final_versionS P I E Conference on Visual Communications and Image Processing 2005, Beijing, China, 12-15 July 2005. In Proceedings Of Spie - The International Society For Optical Engineering, 2005, v. 5960 n. 4, p. 59605V-1 - 59605V-

Content-aware photo collage using circle packing

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Effect of atomic ordering on hydrogen dissociation on Ni₃Fe surfaces

2008-2009 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Diagnostic Value of Methylated Human Telomerase Reverse Transcriptase in Human Cancers: A Meta-Analysis

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Electrical and FT-IR measurements of undoped N-type INP materials grown from various stoichiometric melts

P-rich, In-rich and Stoichiometric undoped InP melts have been synthesed by phosphorus in-situ injection method. InP crystal ingots have been grown from these melts by Liquid Encapsulated Czochralski (LEC). Samples from these ingots grown from various Stoichiometric melts have been characterized by Hall Effect and Fourier Transform Infrared (FT-IR) spectroscopy measurements respectively. The Hall Effect measurement results indicate that the net carrier concentration of P-inch undoped InP is higher than that of In-rich and Stoichiometric undoped InP materials. FT-IR spectroscopy measurements reveal that there are intensive absorption peaks which have been proved to be hydrogen related indium vacancy complex V InH 4. By comparing FT-IR spectra, it is found that P-rich InP material has the most intensive absorption peak of V InH 4, while In-rich InP material has the weakest absorption peak.published_or_final_versio

Socio-economic and psychological correlates of suicidality among Hong Kong working-age adults: Results from a population-based survey

Background. The global toll of suicide is estimated to be one million lives per year, which exceeded the number of deaths by homicide and war combined. A key step to suicide prevention is to prevent less serious suicidal behaviour to preclude more lethal outcomes. Although 61% of the world's suicides take place in Asia and the suicide rates among middle age groups have been increasing since the economic crisis in many Asian countries, population-based studies of suicidal behaviour among working-age adults in non-western communities are scarce. Method. Data from a population-based survey with 2015 participants were used to estimate the prevalence of suicidal ideation and behaviour among the working-age population in Hong Kong, and to study the associated socio-economic and psychological correlates. We focused particularly on potential modulating factors between life-event-related factors and suicidal ideation. Results. Six per cent of the Hong Kong population aged 20-59 years considered suicide in the past year, while 1.4% attempted suicide. Hopelessness, reasons for living, and reluctance to seek help from family and friends had direct association with past-year suicidal ideation. Reasons for living were found to moderate the effect of perceived stress on suicidal ideation. Conclusions. Suicidality is a multi-faceted problem that calls for a multi-sectored, multi-layered approach to prevention. Prevention programmes can work on modulating factors such as reasons for living to reduce suicidal risk in working-age adults. © 2006 Cambridge University Press.published_or_final_versio

Effectiveness of a universal school-based programme for preventing depression in Chinese adolescents: a quasi-experimental pilot study

BACKGROUND: Evidence of the effectiveness, rather than efficacy, of universal school-based programmes for preventing depression among adolescents is limited. This study examined the effectiveness of a universal depression prevention programme, 'The Little Prince is Depressed' (LPD), which adopted the cognitive-behavioural model and aimed to reduce depressive symptoms and enhance protective factors of depression among secondary school students in Hong Kong. METHODS: A quasi-experimental design was adopted for this pilot study. Thirteen classes were assigned to the intervention or control conditions according to the deliberation of the programme administrator of the four participating schools. Implementation was carried out in two phases, with a professional-led first phase and teacher-led programme second phase. LPD consisted of a 12-week school-based face-to-face programme with psycho-educational lessons and homework assignments. RESULTS: Students completed the programme generally showed positive development in help-seeking attitudes and self-esteem. For students who had more depressive symptoms at pre-assessment, the programme was found to be significant in enhancing cognitive-restructuring skills and support-seeking behaviours. The programme was not, however, found to be statistically significant in reducing depressive symptoms of the participants over the study period. LIMITATIONS: A small sample size, a high attrition rate, and a short follow-up time frame. CONCLUSIONS: The LPD programme was successful in building resilience of the students in general and enhancing the cognitive-behavioural skills of students with depressive symptoms. While we did not find sufficient evidence for concluding that the LPD was effective in reducing depressive symptoms, we believe that these results highlight the challenges of implementing evidence-based practices generated from highly controlled environments in real-life settings.postprin

An Early Warning System for Detecting H1N1 Disease Outbreak - A Spatio-temporal Approach

The outbreaks of new and emerging infectious diseases in recent decades have caused widespread social and economic disruptions in the global economy. Various guidelines for pandemic influenza planning are based upon traditional infection control, best practice and evidence. This article describes the development of an early warning system for detecting disease outbreaks in the urban setting of Hong Kong, using 216 confirmed cases of H1N1 influenza from 1 May 2009 to 20 June 2009. The prediction model uses two variables – daily influenza cases and population numbers – as input to the spatio-temporal and stochastic SEIR model to forecast impending disease cases. The fairly encouraging forecast accuracy metrics for the 1- and 2-day advance prediction suggest that the number of impending cases could be estimated with some degree of certainty. Much like a weather forecast system, the procedure combines technical and scientific skills using empirical data but the interpretation requires experience and intuitive reasoning.postprin