550 research outputs found

    Effects analysis of three kinds of operation methods in treatment of dacryocystitis

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    AIM: To investigate the effects on patients with chronic dacryocystitis treated with three methods: external dacryocystorhinostomy(EDCR), intranasal endoscopic dacryocystorhinostomy(IEDCR)and Nd:YAG laser dacryoplasty, and to explore the best operation method. <p>METHODS:Totally 182 cases(202 eyes)were randomly divided into three groups, using EDCR, IEDCR and Nd:YAG laser dacryoplasty respectively, postoperative follow- up lasted 6-24months.<p>RESULTS: The success rate of three groups were 93.9%, 92.3% and 71.1% respectively. There was not significant difference between group EDCR and group IEDCR(<i>P</i>>0.05). There was significant difference between group Nd:YAG laser dacryoplasty and other two groups(<i>P</i><0.05).<p>CONCLUSION: EDCR and IEDCR are effective methods. Especially IEDCR is minimal invasive technique and worthy of promotion and application

    Computational Modeling and Experimental Study on Optical Microresonators using Optimal Spherical Structure for Chemical Sensing

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    Chemical sensors based on optical microresonators have been demonstrated highly sensitive by monitoring the refractive index (RI) changes in the surrounding area near the resonator surface. In an optical resonator, the Whispering Gallery Modes (WGMs) with high quality (Q) factor supported by the spherical symmetric structure interacts with the contiguous background through evanescent field. Highly sensitive detection can be realized because of the long lifetime of the photons. The computational models of solid glass microspheres and hollow glass spheres with porous wall (PW-HGM) were established. These two types of microresonators were studied through simulations. The PWHGM resonator was proved as an optimal chemical sensor and verified by experiments and compared for chemical vapor detection. The simulation and experimental results agreed well in the sensing trends for PW-HGM microresonator

    CODAS methods for multiple attribute group decision making with interval-valued bipolar uncertain linguistic information and their application to risk assessment of Chinese enterprises’ overseas mergers and acquisitions

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    Bipolar fuzzy set theory has been successfully applied in some areas, but there are situations in real life which can’t be represented by bipolar fuzzy sets. However, all the existing approaches are unsuitable to describe the positive and negative membership degree an element to an uncertain linguistic label to have an interval value, which can reflect the decision maker’s confidence level when they are making an evaluation. In order to overcome this limit, we propose the definition of interval-valued bipolar uncertain linguistic sets (IVBULSs) to solve this problem based on the bipolar fuzzy sets and uncertain linguistic information processing models. In this paper, we extend the traditional information aggregating operators to interval-valued bipolar uncertain linguistic sets (IVBULSs) and propose some IVBUL aggregating operators. Then, we extend the CODAS method to solve multiple attribute group decision making (MAGDM) issues with interval-valued bipolar uncertain linguistic numbers (IVBULNs) based on these operators. An example for risk assessment of Chinese enterprises’ overseas mergers and acquisitions (M&As) is given to illustrate the proposed methodology

    Controllable Plasmonic Nanostructures induced by Dual-wavelength Femtosecond Laser Irradiation

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    We demonstrated an abnormal double-peak (annular shaped) energy deposition through dualwavelength synthesis of the fundamental frequency (ω) and the second-harmonic frequency (2ω) of a femtosecond (fs) Ti:sapphire laser. The annular shaped distribution of the dual-wavelength fs laser was confirmed through real beam shape detection. This uniquely simple and flexible technique enables the formation of functional plasmonic nanostructures. We applied this double-peak fs-laser-induced dewetting effect to the controlled fabrication and precise deposition of Au nanostructures, by using a simple, lithography-free, and single-step process. In this process, the double-peak energy-shaped fs laser pulse induces surface patterning of a thin film followed by nanoscale hydrodynamic instability, which is highly controllable under specific irradiation conditions. Nanostructure morphology (shape, size, and distribution) modulation can be achieved by adjusting the laser irradiation parameters, and the subsequent ion-beam polishing enables further dimensional reduction and removal of the surrounding film. The unique optical properties of the resulting nanostructure are highly sensitive to the shape and size of the nanostructure. In contrast to a nanoparticle, the resonance-scattering spectrum of an Au nanobump exhibites two resonance peaks. These suggest that the dual-wavelength fs laserbased dewetting of thin films can be an effective means for the scalable manufacturing of patterned functional nanostructures

    Assessing the utility of structure in amorphous materials

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    This paper presents a set of general strategies for the analysis of structure in amorphous materials and a general approach to assessing the utility of a selected structural description. Measures of structural diversity and utility are defined and applied to two model glass forming binary atomic alloys. In addition, a new measure of incipient crystal-like organization is introduced, suitable for cases where the stable crystal is a compound structure

    Manipulation of LIPSS orientation on silicon surfaces using orthogonally polarized femtosecond laser double-pulse trains

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    Laser-induced periodic surface structures (LIPSS) provide an easy and costeffective means of fabricating gratings and have been widely studied in recent decades. To overcome the challenge of orientation controllability, we developed a feasible and efficient method for manipulating the orientation of LIPSS in real time. Specifically, we used orthogonally polarized and equal-energy femtosecond laser (50 fs, 800 nm) double-pulse trains with time delay about 1ps, total peak laser fluence about 1.0 J/cm2, laser repetition frequency at 100 Hz and scanning speed at 150 ÎĽm/s to manipulate the LIPSS orientation on silicon surfaces perpendicular to the scanning direction, regardless of the scanning paths. The underlying mechanism is attributed to the periodic energy deposition along the direction of surface plasmon polaritons (SPPs), which can be controlled oriented along the scanning direction in orthogonally polarized femtosecond laser double-pulse trains surface scan processing. An application of structural colors presents the functionality of our method

    Manipulation of LIPSS orientation on silicon surfaces using orthogonally polarized femtosecond laser double-pulse trains

    Get PDF
    Laser-induced periodic surface structures (LIPSS) provide an easy and costeffective means of fabricating gratings and have been widely studied in recent decades. To overcome the challenge of orientation controllability, we developed a feasible and efficient method for manipulating the orientation of LIPSS in real time. Specifically, we used orthogonally polarized and equal-energy femtosecond laser (50 fs, 800 nm) double-pulse trains with time delay about 1ps, total peak laser fluence about 1.0 J/cm2, laser repetition frequency at 100 Hz and scanning speed at 150 ÎĽm/s to manipulate the LIPSS orientation on silicon surfaces perpendicular to the scanning direction, regardless of the scanning paths. The underlying mechanism is attributed to the periodic energy deposition along the direction of surface plasmon polaritons (SPPs), which can be controlled oriented along the scanning direction in orthogonally polarized femtosecond laser double-pulse trains surface scan processing. An application of structural colors presents the functionality of our method

    The properties of the high-mass star formation region IRAS22475+5939

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    IRAS22475+5939 has been well researched by previous astronomers. But we still get some new characteristics about it, using the first observations in lines of CO J=2-1,13CO J=2-1,13CO J=3-2 by the KOSMA 3 m telescope. The mapping of the intensity ratio of 13CO J=3-2 and 13CO J=2-1 shows the distribution of the temperature with two peaks, which don't coincide with IRAS22475+5939 source and the center of the HII region, but at the edge of the HII region. The overlays of the Spitzer IRAC 8um and CO contours indicate that they are associated with each other and the strongest polycyclic aromatic hydrocarbons (PAHs) emission is at the position of IRAS22475+5939 source. While the IRAS LRS spectrum at 7-23 um and the PHT-s spectrum at 2-12 um of IRAS22475+5939 source also exhibit strong PAHs emission characters at the main PAH bands. The diversity of PAH family should be responsible for the plateaus of PAHs emission in the PHT-s spectrum and the IRAS-LRS spectrum. An analysis and modeling in infrared bands suggest that IRAS22475+5939 is more likely to be a Class I YSO. Where this is the case, the star is likely to have a temperature T_{EFF} \sim 9995.8 K, mass \sim15.34 M_(sun), luminosity \sim 1.54*10^4 L_(sun) and age \sim 1.54*10^4 yr. The model shows that the circumstellar disc emission is important for the wavelength between 1 and 10 um, otherwise, envelope fluxes for lambda >10 um. The bipolar outflow is confirmed in the molecular cloud. The excited star of the HII region has the chance to be the driving source of the outflow. The high resolution is required.Comment: 12 pages, 20 figures and 5 tables, Accepted for publication in RA
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