342 research outputs found

    A possible mechanism to tune magneto-electroluminescence in organic light-emitting diodes through adjusting the triplet exciton density

    Get PDF
    At 15 K, the high field decay of magneto-electroluminescence (MEL) in tris (8-hydroxyquinoine) aluminum (Alq 3)-based organic light-emitting diodes is greatly suppressed by mixing hole transport material N,N′-bis(naphthalen-1-y)-N,N′-bis(phenyl) benzidine (NPB) into Alq 3 emission layer. The positive correlation between the MEL decay and the triplet exciton density indicates the reduced triplet exciton density is the major contributing factor. The change of triplet exciton density and then the MEL upon NPB mixing may result from the strengths change of charge-triplets interaction, in which the injected charges flowing through the exciton formation zone without forming static space charges play the most important role. © 2011 American Institute of Physics.published_or_final_versio

    Spatio-Temporal Characteristics of Global Warming in the Tibetan Plateau during the Last 50 Years Based on a Generalised Temperature Zone - Elevation Model

    Get PDF
    Temperature is one of the primary factors influencing the climate and ecosystem, and examining its change and fluctuation could elucidate the formation of novel climate patterns and trends. In this study, we constructed a generalised temperature zone elevation model (GTEM) to assess the trends of climate change and temporal-spatial differences in the Tibetan Plateau (TP) using the annual and monthly mean temperatures from 1961-2010 at 144 meteorological stations in and near the TP. The results showed the following: (1) The TP has undergone robust warming over the study period, and the warming rate was 0.318°C/decade. The warming has accelerated during recent decades, especially in the last 20 years, and the warming has been most significant in the winter months, followed by the spring, autumn and summer seasons. (2) Spatially, the zones that became significantly smaller were the temperature zones of -6°C and -4°C, and these have decreased 499.44 and 454.26 thousand sq km from 1961 to 2010 at average rates of 25.1% and 11.7%, respectively, over every 5-year interval. These quickly shrinking zones were located in the northwestern and central TP. (3) The elevation dependency of climate warming existed in the TP during 1961-2010, but this tendency has gradually been weakening due to more rapid warming at lower elevations than in the middle and upper elevations of the TP during 1991-2010. The higher regions and some low altitude valleys of the TP were the most significantly warming regions under the same categorizing criteria. Experimental evidence shows that the GTEM is an effective method to analyse climate changes in high altitude mountainous regions

    Superlattice in austenitic Ni-Mn-Ga shape memory microwires

    Get PDF
    The link between microstructure evolution, micromodulated domain and the structure transformation of Ni-Mn-Ga shape memory microwires prepared with rapid solidification is studied systematically by TEM and HRTEM. Multiple microdomain structures are determined according to the corresponding diffraction spots. The domain structure with a periodic distortion is a kind of characteristic of premartensitic phase. When cooling below the martensitic transformation temperature, the austenitic phase transforms to modulated 5M martensite, and the sequence of phase transformation can finally be confirmed from austenite to premartensite to 5M martensite during cooling. The characterization of micromodulated domain and the structure characteristics of austenite at atomic scale provide comprehensive understanding on the martensitic phase transformation route. (C) 2018 Published by Elsevier B.V.</p

    Long-term structural performance monitoring system for the Shanghai Tower

    Get PDF
    Author name used in this manuscript: You-Lin Xu2012-2013 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe

    From RNAi Screens to Molecular Function in Embryonic Stem Cells

    Get PDF
    The ability of embryonic stem (ES) cells to generate any of the around 220 cell types of the adult body has fascinated scientists ever since their discovery. The capacity to re-program fully differentiated cells into induced pluripotent stem (iPS) cells has further stimulated the interest in ES cell research. Fueled by this interest, intense research has provided new insights into the biology of ES cells in the recent past. The development of large-scale and high throughput RNAi technologies has made it possible to sample the role of every gene in maintaining ES cell identity. Here, we review the RNAi screens performed in ES cells to date and discuss the challenges associated with these large-scale experiments. Furthermore, we provide a perspective on how to streamline the molecular characterization following the initial phenotypic description utilizing bacterial artificial chromosome (BAC) transgenesis

    Retinal microvascular parameters are not associated with reduced renal function in a study of individuals with type 2 diabetes

    Get PDF
    Abstract The eye provides an opportunistic “window” to view the microcirculation. There is published evidence of an association between retinal microvascular calibre and renal function measured by estimated glomerular filtration rate (eGFR) in individuals with diabetes mellitus. Beyond vascular calibre, few studies have considered other microvascular geometrical features. Here we report novel null findings for measures of vascular spread (vessel fractal dimension), tortuosity, and branching patterns and their relationship with renal function in type 2 diabetes over a mean of 3 years. We performed a nested case-control comparison of multiple retinal vascular parameters between individuals with type 2 diabetes and stable (non-progressors) versus declining (progressors) eGFR across two time points within a subset of 1072 participants from the GoDARTS study cohort. Retinal microvascular were measured using VAMPIRE 3.1 software. In unadjusted analyses and following adjustment for age, gender, systolic blood pressure, HbA1C, and diabetic retinopathy, no associations between baseline retinal vascular parameters and risk of eGFR progression were observed. Cross-sectional analysis of follow-up data showed a significant association between retinal arteriolar diameter and eGFR, but this was not maintained following adjustment. These findings are consistent with a lack of predictive capacity for progressive loss of renal function in type 2 diabetes
    corecore