87 research outputs found

    Effect of the oxygen flow on the properties of ITO thin films deposited by ion beam assisted deposition (IBAD)

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    ITO films were deposited onto glass substrates by ion beam assisted deposition method. The oxygen ions were produced using a Kaufman ion source. The oxygen flow was varied from 20 until 60 sccm and the effect of the oxygen flow on properties of ITO films has been studied. The structural properties of the film were characterized by X-ray diffraction and atomic force microscopy. The optical properties were characterized by optical transmission measurements and the optical constants (refractive index n and extinction coefficient k) and film thickness have been obtained by fitting the transmittance using a semi-quantum model. The electrical properties were characterized by Hall effect measurements. It has been found that the ITO film with low electrical resistivity and high transmittance can be obtained with 40 sccm oxygen flow (the working pressure is about 2.3 × 10−2 Pa at this oxygen flow).Fundação para a Ciência e a Tecnologia (FCT) - SFRH-BSAB-514

    Interaction-free, single-pixel quantum imaging with undetected photons

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    A typical imaging scenario requires three basic ingredients: 1. a light source that emits light, which in turn interacts and scatters off the object of interest; 2. detection of the light being scattered from the object and 3. a detector with spatial resolution. These indispensable ingredients in typical imaging scenarios may limit their applicability in the imaging of biological or other sensitive specimens due to unavailable photon-starved detection capabilities and inevitable damage induced by interaction. Here, we propose and experimentally realize a quantum imaging protocol that alleviates all three requirements. By embedding a single-photon Michelson interferometer into a nonlinear interferometer based on induced coherence and harnessing single-pixel imaging technique, we demonstrate interaction-free, single-pixel quantum imaging of a structured object with undetected photons. Thereby, we push the capability of quantum imaging to the extreme point in which no interaction is required between object and photons and the detection requirement is greatly reduced. Our work paves the path for applications in characterizing delicate samples with single-pixel imaging at silicon-detectable wavelengths

    Influence of concentration of vanadium in zinc oxide on structural and optical properties with lower concentration

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    ZnO films doped with different vanadium concentrations are deposited onto glass substrates by dc reactive magnetron sputtering using a zinc target doped with vanadium. The vanadium concentrations are examined by energy dispersive spectroscopy (EDS) and the charge state of vanadium in ZnO thin films is characterized by x-ray photoelectron spectroscopy. The results of x-ray diffraction (XRD) show that all the films have a wurtzite structure and grow mainly in the c-axis orientation. The grain size and residual stress in the deposited films are estimated by fitting the XRD results. The optical properties of the films are studied by measuring the transmittance. The optical constants (refractive index and extinction coefficient) and the film thickness are obtained by fitting the transmittance. All the results are discussed in relation with the doping of the vanadium.Supported by the National Natural Science Foundation of China under Grant Nos 60576016, 10774013, 10804006 and 10434030 (key project), the National High-Tech Research and Development Program of China under Grant No 2006AA03Z0412, the Natural Science Foundation of Beijing under Grant No 2073030, the National Basic Research Program of China under Grant No 2003CB314707, and Beijing Jiao Tong University under Grants Nos 2005SM057, 2006XM043 and 141028522

    Multi-frame image restoration method for novel rotating synthetic aperture imaging system

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    Abstract The novel rotating synthetic aperture (RSA) optical imaging system is an important development direction for future high-resolution optical remote sensing satellites in geostationary orbit. However, owing to the rotating rectangular pupil, the point spread function of the RSA system has an asymmetric spatial distribution, and the images obtained using the primary mirror from different rotation angles have nonuniform blur degradation. Moreover, platform vibration and pupil rotation have coupling effects on the RSA imaging, resulting in further radiometric and geometric quality degradation. To address these problems, the image degradation characteristics are first analyzed according to the imaging mechanism. Then, combined with the theory of mutual information, an image registration method is suggested by introducing the orientation gradient information. From this, a multi-frame image restoration model is proposed based on the directional gradient prior of the RSA system image. From the perspective of interpretation and application, when the aspect ratio is less than 3, the proposed inversion restoration method can achieve a satisfactory processing performance. This work can provide engineering application reference for the future space application of RSA imaging technology

    Structure and optical properties of ZnO:V thin films with different doping concentration

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    A series of ZnO thin films doped with various vanadium concentrations were prepared on glass substrates by direct current reactive magnetron sputtering. The results of the X-ray diffraction (XRD) show that the films with doping concentration less than 10 at.% have a wurtzite structure and grow mainly along the c-axis orientation. The residual stress, estimated by fitting the XRD diffraction peaks, increases with the doping concentration and the grain size also has been calculated from the XRD results, decreases with increasing the doping concentration. The surface morphology of the ZnO:V thin films was examined by SEM. The optical constants (refractive index and extinction coefficient) and the film thickness have been obtained by fitting the transmittance. The optical band gap changed from 3.12 eV to 3.60 eV as doping concentration increased from 1.8 at.% to 13 at.% mol. All the results have been discussed in relation with doping concentrationThe authors express their thanks to the NSFC (60576016 and 10774013), 863 program (2006AA03Z0412), BNSFC (2073030), 973 Program (2003CB314707), Key program of NSFC(10434030) and FBJTU (2005SM057 and 2006XM043) and Beijing Jiao Tong University Doctor Science Creative Grants No. 48027

    Targeting CBLB as a potential therapeutic approach for disseminated candidiasis

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    We thank J.M. Penninger (University of Toronto) for providing Cblb−/− mice, Y. Iwakura (Tokyo University of Science) for providing Clec4n−/− mice, S. Lipkowitz (National Cancer Institute, US National Institutes of Health) for providing Cblb constructs, X. Lin (MD Anderson Cancer Center) for providing the antibody to mouse dectin-3 and Card9−/− bone marrow cells, P.R. Sundstrom (Dartmouth University) for providing the C. albicans cap1 mutant, and L.D. Chaves (University at Buffalo) for flow cytometric analysis of myeloid cells in the kidneys. We also thank A. Lovett-Racke (Ohio State University) for her advice on in vivo Cblb-knockdown experiments. This work was supported by the US National Institutes of Health (grants R01 AI090901, R01 AI123253, and R21 AI117547; all to J.Z.), the American Heart Association (AHA Great Rivers Associate Grant-in-Aid grant 16GRNT26990004; J.Z.), a start-up fund from the Ohio State University College of Medicine (J.Z.), and the Wellcome Trust (G.D.B.).Peer reviewedPostprin

    Protocol for a Single-Center Randomized Controlled Trial of Percutaneous Coronary Intervention Via Distal Transradial Access Versus Transradial Access

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    Background: Although transradial access (TRA) has become the main vascular access for coronary intervention, its high radial artery occlusion rate limits its application in some patients. Studies have shown that compared with TRA, distal transradial access (dTRA) with the snuffbox area or the Hegu acupoint area as the puncture point significantly decreases the incidence of radial artery occlusion. However, no randomized controlled study has confirmed the safety and efficacy of coronary artery intervention via dTRA in China. Methods and analyses: This single-center, prospective, randomized controlled, superiority open-label study will enroll 428 consecutive patients with coronary heart disease undergoing percutaneous coronary intervention as the study population. After preoperative evaluation, the participants will be randomly divided into a study group (dTRA) and control group (TRA) in a 1:1 ratio. The primary endpoint (radial artery occlusion at 24 hours after operation) and secondary endpoint events will be evaluated and recorded. Study registration: This study has been registered in the Chinese Clinical Trial Registry (registration number: ChiCTR2300073902)
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