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991.
K S Divy Athulya K Madhu T U Umadevi T Suprabh P. Radhakrishnan Nair Suresh Mathew 《半导体学报》2017,38(6):063002-8
In this paper an improvement in the photocatalytic performance of TiO2 was carried out via hybridizing with graphene. Graphene-TiO2 (GR-TiO2)nanocomposites with different weight addition ratios of graphene oxide (GO) have been prepared via a facile microwave irradiation of GO and tetrabutyl titanate in isopropyl alcohol. Raman spectroscopy (RS), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-visible spectroscopy (UV-vis), Fourier transform infrared spectra (FTIR), energy dispersive X-ray spectroscopy (EDX) and photoluminescence spectra (PL) are employed to determine the properties of the samples. Microwave irradiation can heat the reactant to a higher temperature in a short time, simultaneously GO is reduced to graphene and TiO2 nanoparticles grown on the surface of GR. GR-TiO2 nanocomposites synthesized via this approach have efficient electron conductivity in GR, resulting in a reduced electron-hole recombination rate. Among the synthesized nanocomposites, GT-8wt% exhibited the best photocatalytic activity toward photocatalytic degradation of MB. Our current work provides a new insight for the fabrication of GR-TiO2 nanocomposites within a short reaction time and also explains the mechanism of photocatalysis employing radical and hole scavengers. 相似文献
992.
An enhancement mode p-GaN gate AlGaN/GaN HEMT is proposed and a physics based virtual source charge model with Landauer approach for electron transport has been developed using Verilog-A and simulated using Cadence Spectre, in order to predict device characteristics such as threshold voltage, drain current and gate capacitance. The drain current model incorporates important physical effects such as velocity saturation, short channel effects like DIBL (drain induced barrier lowering), channel length modulation (CLM), and mobility degradation due to self-heating. The predicted Id-Vds, Id-Vgs, and C-V characteristics show an excellent agreement with the experimental data for both drain current and capacitance which validate the model. The developed model was then utilized to design and simulate a single-pole single-throw (SPST) RF switch. 相似文献
993.
An approach to automated detection of tumors in mammograms 总被引:5,自引:0,他引:5
An automated system for detecting and classifying particular types of tumors in digitized mammograms is described. The analysis of mammograms is performed in two stages. First, the system identifies pixel groupings that may correspond to tumors. Next, detected pixel groupings are subjected to classification. The essence of the first processing stage is multiresolution image processing based on fuzzy pyramid linking. The second stage uses a classification hierarchy to identify benign and malignant tumors. Each level of the hierarchy uses deterministic or Bayes classifiers and a particular measurement. The measurements pertain to shape and intensity characteristics of particular types of tumors. The classification hierarchy is organized in such a way that the simplest measurements are used at the top, with the system stepping through the hierarchy only when it cannot classify the detected pixel groupings with certainty. 相似文献
994.
Yang D Bertram JM Converse MC O'Rourke AP Webster JG Hagness SC Will JA Mahvi DM 《IEEE transactions on bio-medical engineering》2006,53(3):533-537
We report a novel coaxial antenna for hepatic microwave ablation. This device uses a floating sleeve, that is, a metal conductor electrically isolated from the outer connector of the antenna coaxial body, to achieve a highly localized specific absorption rate pattern that is independent of insertion depth. This floating sleeve coaxial dipole antenna has low power reflection in the 2.4-GHz IMS band. Ex vivo experiments confirm our numerical simulation results. Index Terms-Ablation, coaxial aperture antennas, finite element methods, floating sleeve, microwave heating. 相似文献
995.
Chung AJ Deligianni F Shah P Wells A Yang GZ 《IEEE transactions on medical imaging》2006,25(4):503-513
This paper presents an image-based method for virtual bronchoscope with photo-realistic rendering. The technique is based on recovering bidirectional reflectance distribution function (BRDF) parameters in an environment where the choice of viewing positions, directions, and illumination conditions are restricted. Video images of bronchoscopy examinations are combined with patient-specific three-dimensional (3-D) computed tomography data through two-dimensional (2-D)/3-D registration and shading model parameters are then recovered by exploiting the restricted lighting configurations imposed by the bronchoscope. With the proposed technique, the recovered BRDF is used to predict the expected shading intensity, allowing a texture map independent of lighting conditions to be extracted from each video frame. To correct for disocclusion artefacts, statistical texture synthesis was used to recreate the missing areas. New views not present in the original bronchoscopy video are rendered by evaluating the BRDF with different viewing and illumination parameters. This allows free navigation of the acquired 3-D model with enhanced photo-realism. To assess the practical value of the proposed technique, a detailed visual scoring that involves both real and rendered bronchoscope images is conducted. 相似文献
996.
GUO Ning LIANG Xiong-jian Beijing University of Posts Telecommunications Beijing P.R.China 《中国邮电高校学报(英文版)》2005,12(2)
1IntroductionIn the long evolution, many life-forms in the naturalecosystem have formed very perfect and exact system,which has uncommon capability to adapt the change ofthe environment and can use the substance andthe ener-gy efficiently. Moreover ,the telecommunicationindus-trylooks like the natural ecosystem. Every telecommu-nication enterprise can be regarded as an ani mated life-form,competing and cooperating with others ,adjustingitself gradually to adapt the environment that changeswith… 相似文献
997.
ZHAO Dong-fan LIU LeiCollege of Computer Science Technology Jilin University Changchun P.R. China 《中国邮电高校学报(英文版)》2005,12(3)
1 Buffer Overflow Detection Technology Buffer overflow detection approaches can be dividedinto two categories :static approaches and dynamic ap-proaches[1 ,7 ~9]. Both dynamic approaches , such asStackGuard[2],StackShield[3],and Ref .[6] ,andstaticapproaches,such as ITS4[4], Rats[5],and Refs .[14 ~15] ,have their own disadvantages andli mitations .Dy-namic approaches increase the system operation spend-ing,and could become a service rejected attack easily.This paper presents anapproachto… 相似文献
998.
1 IntroductionOrthogonalFrequencyDivisionMultiplexing(OFDM) [1~5] isapromisingtechniqueforhighda ta ratetransmission ,especiallyinwirelesscommuni cationsystems,whichcaneffectivelyminimizeIn tersymbolInterference (ISI)causedbydelayspreadawingtomultipathfading .… 相似文献
999.
1 IntroductionInmanyapplications,suchasradar,sonar,geophysics,radiocommunicationandmedicalimag ing ,theproblemoftwo dimensionalfrequencyesti mationhasreceivedalotofattentioninrecentyears.InthecaseofadditivewhiteGaussiannoise,numerousmethodssuchasMEMP[1 ] ,MUS… 相似文献
1000.
Z. Liang Andre Arens P. Kanschat R. Rudolf 《电力电子》2005,3(5):42-47,50
本文基于SOI技术,开发了一款新型的600V/0.3A 6-pack IGBT/MOSFET驱动器芯片.此款名为6ED003L06-F的芯片集成了三相电平转换、门极驱动和电路保护等诸多特性,在缩小芯片尺寸的同时也提高了性能,例如抗反相瞬态电压的鲁棒性等。另外,本文还利用该SOI驱动芯片开发了SmartPACK/SmartPIM系列新型IPM模块,该模块在一块基于DCB层的底板上集成了SOI驱动器,600V IGBT3和自举功能,并且无须支承板。这种IPM可对应6A-12A的额定电流,同时具有结构紧凑、成本低廉、操作简单等优点,适用于各类小功率驱动特别是消费类驱动应用。 相似文献