Current Issue : April - June Volume : 2019 Issue Number : 2 Articles : 6 Articles
A method for adjusting the working distance and spot size of a fiber probe while\nsuppressing or enhancing the back-coupling to the lead-in fiber is presented. As the optical fiber\nprobe, a lensed optical fiber (LOF) was made by splicing a short piece of coreless silica fiber (CSF) on\na single-mode fiber and forming a lens at the end of the CSF. By controlling the length of the CSF and\nthe radius of lens curvature, the optical properties of the LOF were adjusted. The evolution of the\nbeam in the LOF was analyzed by using the Gaussian ABCD matrix method. To confirm the idea\nexperimentally, 17 LOF samples were fabricated and analyzed theoretically and also experimentally.\nThe results show that it is feasible in designing the LOF to be more suitable for specific or dedicated\napplications. Applications in physical sensing and biomedical imaging fields are expected....
The three-point bending behavior of a single Au nanowire deformed by an atomic force\nmicroscope was monitored by coherent X-ray diffraction using a sub-micrometer sized hard X-ray\nbeam. Three-dimensional reciprocal-space maps were recorded before and after deformation by\nstandard rocking curves and were measured by scanning the energy of the incident X-ray beam\nduring deformation at different loading stages. The mechanical behavior of the nanowire was\nvisualized in reciprocal space and a complex deformation mechanism is described. In addition to the\nexpected bending of the nanowire, torsion was detected. Bending and torsion angles were quantified\nfrom the high-resolution diffraction data....
Laser-based displays have attracted much attention owing to large-size screen\nand full-color gamut compared with other displays such as liquid crystal display\nand light emitting diode. However, there exists a phenomenon, speckle,\nlimits the applications of laser display because of the high coherence of laser.\nIn this work, we developed an electrically injected 6xx nm dual-emitter laser\nwhich combines the low-spatial coherence with the high-power. The output\npower of the dual-emitter laser exceeds 500 mW under�����....
In this paper, we study various cosmological models involving new nonlinear forms of\ninteraction between cold dark matter (DM) and dark energy (DE) assuming that DE is a barotropic\nfluid. The interactions are nonlinear either due to log.................
This minireview aims at providing a complete survey concerning the use of X-ray\nabsorption spectroscopy (XAS) for time-resolved studies of electrochemical and photoelectrochemical\nphenomena. We will see that time resolution can range from the femto-picosecond to the second\n(or more) scale and that this joins the valuable throughput typical of XAS, which allows for\ndetermining the oxidation state of the investigated element, together with its local structure. We will\nanalyze four different techniques that use different approaches to exploit the in real time capabilities\nof XAS. These are quick-XAS, energy dispersive XAS, pump & probe XAS and fixed-energy X-ray\nabsorption voltammetry. In the conclusions, we will analyze possible future perspectives for\nthese techniques....
The technique of Faraday tomography is a key tool for the study of magnetised plasmas in the\nnew era of broadband radio-polarisation observations. In particular, observations at metre wavelengths\nprovide significantly better Faraday depth accuracies compared to traditional centimetre-wavelength\nobservations. However, the effect of Faraday depolarisation makes the polarised signal very challenging\nto detect at metre wavelengths (MHz frequencies). In this work, Faraday tomography is used to\ncharacterise the Faraday rotation properties of polarised sources found in data from the LOFAR\nTwo-Metre Sky Survey (LoTSS). Of the 76 extragalactic polarised sources analysed here, we find that\nall host a radio-loud AGN (Active Galactic Nucleus)��.....
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