955 research outputs found

    Transmission area and two-photon correlated imaging

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    The relationship between transmission area of an object imaged and the visibility of its image is investigated in a lensless system. We show that the changes of the visibility are quite different when the transmission area is varied by different manners. An increase of the transmission by adding the slit number leads to a decrease of the visibility. While, the change is adverse when the slit width is widened for a given distance between two slits.Comment: 10 pages, 4 figure

    The Complaint Response Strategies in the Airline Outbound Calls from the Perspective of Rapport Management

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    Customer complaints can have a significant influence on the rapport and relationships between the customer and the company. This article aims to study the company’s response strategies for customer complaints from the perspective of rapport management, collecting the data from the airline outbound calls. Results show that there are three types of customer complaints and three kinds of response strategies related, but the effect of strategies on rapport management is not satisfying

    Sub-wavelength Coherent Imaging of a Pure-Phase Object with Thermal Light

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    We report, for the first time, the observation of sub-wavelength coherent image of a pure phase object with thermal light,which represents an accurate Fourier transform. We demonstrate that ghost-imaging scheme (GI) retrieves amplitude transmittance knowledge of objects rather than the transmitted intensities as the HBT-type imaging scheme does.Comment: 5 pages, 4 figures; Any comments pls. contact: [email protected]

    Improving the imaging ability of ultrasound-modulated optical tomography with spectral-hole burning

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    Ultrasound-modulated optical tomography is a hybrid imaging technique based on detection of the diffused light modulated by a focused ultrasonic wave inside a scattering medium. With the combined advantages of ultrasonic resolution and optical contrast, UOT is ideal for deep tissue imaging. Its growth in popularity and application, however, is hindered by the low efficiency in detecting the modulated diffused photons. Research activities on UOT have therefore been centered on improving its signal detection efficiency by exploring various technical solutions. A prime example is the use of spectral-hole burning (SHB) in UOT. By applying SHB crystal as a spectral filter, one modulation sideband of the diffused light can be efficiently selected while all the other frequency components are strongly suppressed. Immune to both the spatial and temporal incoherence of the signal with a high enough on/off ratio, SHB can boost the UOT imaging ability dramatically and push it towards practical applications. We compare SHB with the other technologies that have been applied to UOT, and identify the unique features that make SHB a preferable tool for UOT. We also discuss the desired improvements from the SHB side, which will help UOT pave the way from research to everyday life

    Focusing light into turbid media: time-reversed ultrasonically encoded (TRUE) focusing

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    In turbid media such as biological tissues, light undergoes multiple scattering. Consequently, it is not possible to focus light at depths beyond one transport mean free path in such media. To break through this limit, we proposed and experimentally demonstrated a novel technique, based on ultrasonic encoding of diffused laser light and optical time reversal, which effectively focuses light into a turbid medium. In the experimental implementation of the Time-Reversed Ultrasonically Encoded (TRUE) optical focusing, a turbid medium was illuminated by a laser beam with a long coherence length. The incident light was multiply scattered inside the medium and ultrasonically encoded within the ultrasonic focal zone. The wavefront of the ultrasonically encoded light was then time reversed by a Phase Conjugate Mirror (PCM) outside the medium. The time-reversed (or phase conjugated) optical wavefront traced back the trajectories of the ultrasonically encoded diffused light, and converged to the ultrasonic focal zone. With a commercially available photorefractive crystal as the PCM, the main approaches for increasing focusing depth are to improve the efficiencies of ultrasonic encoding and time reversal. Our recent experiments showed that light can be focused into a 5-mm thick tissue-mimicking phantom (optical thickness = 50, i.e., geometric thickness = 50 mean free paths) with a dynamically adjustable focus. The TRUE optical focusing opens a door to focusing light into turbid media or manipulating light-matter interactions

    Synchrotron radiation circular dichroism: a new tool for identification of point-mutation protein

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    AbstractMany diseases are associated with the mutation of wild-type proteins. Usually, a point mutation can lead to severe clinical outcomes. Few techniques have the ability to detect the minute differences between the wild-type and mutant proteins in solution under near physiological conditions. Circular dichroism (CD) is an established and valuable technique for examining protein structure. Because of its ability to sensitively detect conformational changes, it has important potential for identification of mutant protein. Synchrotron radiation CD (SRCD) offers significant enhancements with respect to conventional CD spectroscopy, which will enable its usage for high-resolution conformation detection and as a tool in the point-mutation protein identification. In this report, SRCD was used, as an example, to identify the point-mutations of human phosphoribosyl pyrophosphate synthetase 1 which were associated with an X chromosome-linked disease

    The relationship between CSR and CFP: the lag effect, virtuous circle, and non-linear relationship in this linkage

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    This dissertation discusses the relationship between corporate socially responsible and corporate financial performance. I use the UK’s firms as the sample and classify them by Industries. The data across from 2012 to 2017. This dissertation tests three questions and they are (1) the lagged relationship between the two, (2) the virtuous circle in CSR-CFP linkage, and (3) the non-linear relationship in this nexus. Using the GMM-system method to analyze the data, I found the relationship between the two is varied across industries. The lag effect is present in most of the industries. However, the virtuous circle is not stable in Health Care and Telecommunication Industries. The vicious circle presents in Utilities Industry. In addition, the non-linear relationship is detected in the Basic Materials and Telecommunications Industry, but the directions are varied across the different industry

    Time-reversed ultrasonically encoded optical focusing into tissue-mimicking media with thickness up to 70 mean free paths

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    In turbid media such as biological tissue, multiple scattering hinders direct light focusing at depths beyond one transport mean free path. As a solution to this problem, time-reversed ultrasonically encoded (TRUE) optical focusing is proposed based on ultrasonic encoding of diffused laser light and optical time reversal. In TRUE focusing, a laser beam of long coherence length illuminates a turbid medium, where the incident light undergoes multiple scattering and part of it gets ultrasonically encoded within the ultrasonic focal zone. A conjugated wavefront of the ultrasonically encoded light is then generated by a phase conjugate mirror outside the medium, which traces back the trajectories of the ultrasonically encoded diffused light and converges light to the ultrasonic focal zone. Here, we report the latest experimental improvement in TRUE optical focusing that increases its penetration in tissue-mimicking media from a thickness of 3.75 to 7.00 mm. We also demonstrate that the TRUE focus depends on the focal diameter of the ultrasonic transducer
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