379 research outputs found

    Crystal structure and electronic structure of quaternary semiconductors Cu2_2ZnTiSe4_4 and Cu2_2ZnTiS4_4 for solar cell absorber

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    We design two new I2-II-IV-VI4 quaternary semiconductors Cu2_2ZnTiSe4_4 and Cu2_2ZnTiS4_4, and systematically study the crystal and electronic structure by employing first-principles electronic structure calculations. Among the considered crystal structures, it is confirmed that the band gaps of Cu2_2ZnTiSe4_4 and Cu2_2ZnTiS4_4 originate from the full occupied Cu 3dd valence band and unoccupied Ti 3dd conducting band, and kesterite structure should be the ground state. Furthermore, our calculations indicate that Cu2_2ZnTiSe4_4 and Cu2_2ZnTiS4_4 have comparable band gaps with Cu2_2ZnTSe4_4 and Cu2_2ZnTS4_4, but almost twice larger absorption coefficient α(ω)\alpha(\omega). Thus, the materials are expected to be candidate materials for solar cell absorber.Comment: 4 pages, 4 figure

    Beliefs about medicines and non-adherence in patients with stroke, diabetes mellitus and rheumatoid arthritis: a cross-sectional study in China

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    OBJECTIVES: To investigate beliefs about medicines and their association with medicine adherence in patients with chronic diseases in China. DESIGN: A cross-sectional questionnaire-based study SETTING: Two large urban hospitals in Hefei and Tianjin, China PARTICIPANTS: Hospital inpatients (313 stroke patients) and outpatients (315 diabetic patients and 339 rheumatoid arthritis (RA) patients) were recruited between January 2014 and September 2014. OUTCOME MEASURES: The Beliefs about Medicines Questionnaire (BMQ), assessing patients' beliefs about the specific medicine (Specific-Necessity and Specific-Concerns) prescribed for their conditions (stroke/diabetes/RA) and more general background beliefs about pharmaceuticals as a class of treatment (BMQ-General Benefit, Harm and Overuse); the Perceived Sensitivity to Medicines scale (PSM) assessed patients' beliefs about how sensitive they were to the effects of medicines and the Medication Adherence Report Scale. The association between non-adherence and beliefs about medicines was assessed using a logistic regression model. RESULTS: Patients with diabetes mellitus had a stronger perceived need for treatment (mean (SD) Specific-Necessity score, 3.75 (0.40)) than patients with stroke (3.69 (0.53)) and RA (3.66 (0.44)) (p=0.049). Moderate correlations were observed between Specific-Concerns and General-Overuse, General-Harm and PSM (Pearson correlation coefficients, 0.39, 0.49 and 0.49, respectively, p<0.01). Three hundred and eleven patients were non-adherent to their medicine (159 (51.0%) in the stroke group, 60 (26.7%) in the diabetes mellitus group and 62 (19.8%) in the RA group, p<0.01). Across the whole sample, after adjusting for demographic characteristics, non-adherence was associated with patients who had higher concerns about their medicines (OR, 1.35, 95% CI 1.07 to 1.71) and patients who believed that they were personally sensitive to the effects of medications (OR 1.44, 95% CI 1.16 to 1.85). CONCLUSION: The BMQ is a useful tool to identify patients at risk of non-adherence. In the future, adherence intervention studies may use the BMQ to screen for patients who are at risk of non-adherence and to map interventional support

    Towards Top-Down Stereoscopic Image Quality Assessment via Stereo Attention

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    Stereoscopic image quality assessment (SIQA) plays a crucial role in evaluating and improving the visual experience of 3D content. Existing binocular properties and attention-based methods for SIQA have achieved promising performance. However, these bottom-up approaches are inadequate in exploiting the inherent characteristics of the human visual system (HVS). This paper presents a novel network for SIQA via stereo attention, employing a top-down perspective to guide the quality assessment process. Our proposed method realizes the guidance from high-level binocular signals down to low-level monocular signals, while the binocular and monocular information can be calibrated progressively throughout the processing pipeline. We design a generalized Stereo AttenTion (SAT) block to implement the top-down philosophy in stereo perception. This block utilizes the fusion-generated attention map as a high-level binocular modulator, influencing the representation of two low-level monocular features. Additionally, we introduce an Energy Coefficient (EC) to account for recent findings indicating that binocular responses in the primate primary visual cortex are less than the sum of monocular responses. The adaptive EC can tune the magnitude of binocular response flexibly, thus enhancing the formation of robust binocular features within our framework. To extract the most discriminative quality information from the summation and subtraction of the two branches of monocular features, we utilize a dual-pooling strategy that applies min-pooling and max-pooling operations to the respective branches. Experimental results highlight the superiority of our top-down method in simulating the property of visual perception and advancing the state-of-the-art in the SIQA field. The code of this work is available at https://github.com/Fanning-Zhang/SATNet.Comment: 13 pages, 4 figure

    Global Dynamics of an HTLV-1 Model with Cell-to-Cell Infection and Mitosis

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    A mathematical model of human T-cell lymphotropic virus type 1 in vivo with cell-to-cell infection and mitosis is formulated and studied. The basic reproductive number R0 is derived. It is proved that the dynamics of the model can be determined completely by the magnitude of R0. The infection-free equilibrium is globally asymptotically stable (unstable) if R01). There exists a chronic infection equilibrium and it is globally asymptotically stable if R0>1

    Advances in Antenna Design and System Technologies for Next Generation Cellular Systems

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    10.1155/2013/610319International Journal of Antennas and Propagation201361031

    Limits to Sustained Energy Intake XXXI : Effect of Graded Levels of Dietary Fat on Lactation Performance in Swiss Mice

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    We thank the staff of animal facility for their care of the animals. This study was funded by the National Key Research and Development Program of China (SQ2018YFA08003201) and the Chinese Academy of Sciences Strategic Program (XDB13030100).Peer reviewedPostprin
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