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[IEEE 2018 IEEE SmartWorld, Ubiquitous Intelligence & Computing, Advanced & Trusted Computing, Scalable Computing & Communications, Cloud & Big Data Computing, Internet of People and Smart City Innovation (SmartWorld/SCALCOM/UIC/ATC/CBDCom/IOP/SCI) - Guangzhou, China (2018.10.8-2018.10.12)] 2018 IEEE SmartWorld, Ubiquitous Intelligence & Computing, Advanced & Trusted Computing, Scalable Computing & Communications, Cloud & Big Data Computing, Internet of People and Smart City Innovation (SmartWorld/SCALCOM/UIC/ATC/CBDCom/IOP/SCI) - An Efficient Recognition Method for Incomplete Iris Image Based on CNN Model
摘要： The iris of the eye is a research hot spot in the field of biometric identification because of its uniqueness, non-contact and bioactivity. The incompleteness of the iris caused by the acquisition process has brought great uncertainty to the subsequent iris region segmentation and iris code matching, thereby reducing the efficiency of iris recognition. This paper describes a deep convolution neural network model with adaptive incomplete iris preprocessing mechanism. Based on the normalization of the iris image, the incomplete iris preprocessing mechanism adopts the method of making the inner circle or the outer circle. The iris region can be segmented by the line fitting and the circle fitting method for extracting as many iris features as possible. The deep convolution neural network then uses pixel coding of Irregular iris regions to complete the iris pattern classification. The model fully utilizes the characteristics of deep learning, local feature characterization and weight sharing, and realizes the problem of using large sample to compensate the incomplete feature of local feature. The experimental results show that this method has significant accuracy improvement compared with the traditional algorithms.
关键词： iris recognition,convolution neural network,iris image normalization,algorithm
更新于2025-09-23 15:23:52
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Raman Spectroscopic and Microscopic Analysis for Monitoring Renal Osteodystrophy Signatures
摘要： Defining the pathogenesis of renal osteodystrophy (ROD) and its treatment efficacy are difficult, since many factors potentially affect bone quality. In this study, confocal Raman microscopy and parallel statistical analysis were used to identify differences in bone composition between healthy and ROD bone tissues through direct visualization of three main compositional parametric ratios, namely, calcium content, mineral-to-matrix, and carbonate-to-matrix. Besides the substantially lower values found in ROD specimens for these representative ratios, an obvious accumulation of phenylalanine is Raman spectroscopically observed for the first time in ROD samples and reported here. Thus, elevated phenylalanine could also be considered as an indicator of the disease. Since the image results are based on tens of thousands of spectra per sample, not only are the average ratios statistically significantly different for normal and ROD bone, but the method is clearly powerful in distinguishing between the two types of samples. Furthermore, the statistical outcomes demonstrate that only a relatively small number of spectra need to be recorded in order to classify the samples. This work thus opens the possibility of future development of in vivo Raman sensors for assessment of bone structure, remodeling, and mineralization, where different biomarkers are simultaneously detected with unprecedented accuracy.
关键词： Raman spectroscopy,bone composition,statistical analysis,renal osteodystrophy
更新于2025-09-23 15:23:52
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Lewis Acid Catalyzed [3+3] Annulation of Donor-Acceptor Cyclopropanes and Indonyl Alcohols: One Step Synthesis of Substituted Carbazoles with Promising Photophysical Properties
摘要： A highly efficient protocol to access carbazole from donor-acceptor cyclopropane and indonyl alcohol via [3+3] annulation in the presence of a Lewis acid has been demonstrated. This method facilitates the post functionalization of the substituted carbazole into a fully conjugated π-system exhibiting intense emission bands in the visible range of the spectrum and also offers a convenient route toward the synthesis of pityriazole derivatives.
更新于2025-09-23 15:23:52
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Investigation of Electrical Characteristics on LaAlO <sub/>3</sub> /ZrO <sub/>2</sub> /IGZO TFTs with Microwave Annealing
摘要： Conventional thin film transistor suffered from high threshold voltage, poor subthreshold swing, and high operation voltage. These shortcomings make the traditional thin film transistor does not meet the needs with the high-performance, high-resolution, low temperature and energy conservation nowadays. Due to the good selectivity of energy transformation and rapid heating rate, microwave annealing is promising to replace conventional furnace annealing and applied in the investigation. LaAlO3/ZrO2 is employed as gate electrode and gate dielectric layer for a-IGZO TFTs, under the premise that performance of a-IGZO TFTs without decreasing. With adjusting the power/time of microwave annealing, the effect on electrical characteristics of a-IGZO TFTs is investigated.
关键词： ZrO2,Microwave Annealing,a-IGZO TFTs,LaAlO3
更新于2025-09-23 15:23:52
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ZnO Micro- and Nanostructures Obtained by Thermal Oxidation: Microstructure, Morphogenesis, Optical, and Photoluminescence Properties
摘要： ZnO micro- and nanostructures were obtained through thermal oxidation of Zn powders at high temperature under air atmosphere. A detailed study of the microstructure, morphology, optical, and photoluminescence properties of the generated products at different stages of thermal oxidation is presented. It was found that the exposure time has a strong influence on the resulting morphology. The morphogenesis of the different ZnO structures is discussed, and experimental parameters for fabricating ZnO tetrapods, hollow, core-shell, elongated, or rounded structures by thermal oxidation method are proposed on the basis on the obtained results. Notoriously, the crystal lattice of the ZnO structures has negligible residual strain, although, the density of point defects increases when the thermal treatment is extended; as consequence, their visible luminescence upon UV excitation enhances.
关键词： growth mechanism,ZnO structures,thermal oxidation,physical properties
更新于2025-09-23 15:23:52
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Absolute Nonlinear Refractive Index Spectra Determination of Organic Molecules in Solutions
摘要： It has been a great challenge to measure the spectrum of pure bound-electronic third-order nonlinear refraction (n2) of organic chromophores in solutions because of the spurious contribution from the solvent and cuvette walls. In order to circumvent this problem, we present here a new method to obtain highly accurate absolute n2 value of organic molecules in solutions with a self-referenced nonlinear ellipse rotation (NER) technique. As a proof of concept, we measured n2 spectra of two well-know chromophores, rhodamines B and 6G dissolved in methanol, in the range from ~600 to 1200 nm. Our results pointed out that these two dyes present similar dispersion curves with strong negative nonlinearities near the one-photon absorption band and small positive values at long wavelengths. Furthermore, the negative signal of the dyes can be strong enough to cancel and even invert the positive nonlinear refraction of the solvent (methanol) as the solution’s concentration increases. To understand the n2 spectrum and its connection to molecular properties of organic chromophores, we employed the sum-over-states (SOS) approach within the few-energy-level model and observed an excellent agreement between the experimental and theoretical spectra. In this way, we believe that employing our NER technique and the SOS model, it is possible to determine both experimentally and theoretically the absolute magnitude and spectra of pure electronic n2 for a large variety of other organic molecules.
更新于2025-09-23 15:23:52
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Spatial Interpolation Enables Normative Data Comparison in Gaze-Contingent Microperimetry
摘要： PURPOSE. To demonstrate methods that enable visual field sensitivities to be compared with normative data without restriction to a fixed test pattern. METHODS. Healthy participants (n ? 60, age 19–50) undertook microperimetry (MAIA-2) using 237 spatially dense locations up to 138 eccentricity. Surfaces were fit to the mean, variance, and 5th percentile sensitivities. Goodness-of-fit was assessed by refitting the surfaces 1000 times to the dataset and comparing estimated and measured sensitivities at 50 randomly excluded locations. A leave-one-out method was used to compare individual data with the 5th percentile surface. We also considered cases with unknown fovea location by adding error sampled from the distribution of relative fovea–optic disc positions to the test locations and comparing shifted data to the fixed surface. RESULTS. Root mean square (RMS) difference between estimated and measured sensitivities were less than 0.5 dB and less than 1.0 dB for the mean and 5th percentile surfaces, respectively. Root mean square differences were greater for the variance surface, median 1.4 dB, range 0.8 to 2.7 dB. Across all participants 3.9% (interquartile range, 1.8–8.9%) of sensitivities fell beneath the 5th percentile surface, close to the expected 5%. Positional error added to the test grid altered the number of locations falling beneath the 5th percentile surface by less than 1.3% in 95% of participants. CONCLUSIONS. Spatial interpolation of normative data enables comparison of sensitivity measurements from varied visual field locations. Conventional indices and probability maps familiar from standard automated perimetry can be produced. These methods may enhance the clinical use of microperimetry, especially in cases of nonfoveal fixation.
关键词： fundus perimetry,microperimetry,normative database,AMD,gaze-contingent
更新于2025-09-23 15:23:52
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Fast-curing halogen-free flame-retardant epoxy resins and their application in glass fiber-reinforced composites
摘要： A series of novel fast-curing halogen-free flame-retardant epoxy resins were formulated and used to prepare glass fiber-reinforced composites. Dynamic mechanical analysis showed that the optimized epoxy system could be completely cured in 0.5 h at 150°C and had a glass transition temperature (Tg) of above 130°C. The optimized epoxy system was also used as matrix resin to make glass fiber prepregs and composite panels. The flame-retardant properties of the glass fiber-reinforced composites were investigated, including the limiting oxygen index (LOI) and flaming, smoke and toxicity properties. The glass fiber-reinforced composite had good flame retardancy with a UL-94 V-1 rating and high LOI of ≥36%. More significantly, the composite based on the flame-retardant epoxy resin showed lower smoke density compared with those based on phenolic resins. Finally, the glass fiber prepregs were used to fabricate honeycomb sandwich composites. The peel strength of the epoxy-based composites was almost twice that of the composites based on phenolic resin.
关键词： prepregs,fast cure,glass fiber-reinforced composites,halogen-free flame retardancy,epoxy resins
更新于2025-09-23 15:23:52
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Facile and Green Synthesis of Graphene-Based Conductive Adhesives via Liquid Exfoliation Process
摘要： In this study, we report a facile and green process to synthesize high-quality and few-layer graphene (FLG) derived from graphite via a liquid exfoliation process. The corresponding characterizations of FLG, such as scanning electron microscopy (SEM), transmission electron microscope (TEM), atomic force microscopy (AFM) and Raman spectroscopy, were carried out. The results of SEM show that the lateral size of as-synthesized FLG is 1–5 μm. The results of TEM and AFM indicate more than 80% of graphene layers is <10 layers. The most surprising thing is that D/G ratio of graphite and FLG are 0.15 and 0.19, respectively. The result of the similar D/G ratio demonstrates that little structural defects were created via the liquid exfoliation process. Electronic conductivity tests and resistance of composite ?lm, in terms of different contents of graphite/polyvinylidene di?uoride (PVDF) and FLG/PVDF, were carried out. Dramatically, the FLG/PVDF composite demonstrates superior performance compared to the graphite/PVDF composite at the same ratio. In addition, the post-sintering process plays an important role in improving electronic conductivity by 85%. The composition-optimized FLG/PVDF thin ?lm exhibits 81.9 S·cm?1. These results indicate that the developed FLG/PVDF composite adhesives could be a potential candidate for conductive adhesive applications.
关键词： conductive adhesives,liquid exfoliation,graphene,?exiable,polyvinylidene ?uoride
更新于2025-09-23 15:23:52
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Third Order Nonlinear Properties of Pure and Na doped L-Arginine Acetate Single Crystal by Z-scan Technique
摘要： Single crystals of pure and Na doped L-arginine acetate (LAA) has been successfully grown from aqueous solution by slow evaporation technique. The crystalline qualities of the grown crystals were confirmed by powder X-ray diffraction studies. The nonlinear refractive index n2 and nonlinear susceptibility c(3) have been measured through the Z-scan technique. The results indicate that the compound exhibits reverse saturation absorption and self defocusing performance. Non-linear absorption co-efficient (b), the non-linear refractive index (n2), the real and imaginary parts of non-linear susceptibility c (3) have been measured at 632.8 nm.
关键词： Z-scan Technique,Na doped L-arginine acetate (LAA),Crystal
更新于2025-09-23 15:23:52