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Simultaneous Determination of Ultraviolet absorbers and Antibacterial Agents in Textiles by Ultra-High Performance Liquid Chromatography/Orbitrap High Resolution Mass Spectrometry

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World Journal of Engineering and Technology 2017年第1期5卷 1-18页

作者： Chengyun Wang Tangtang Xie Rong Xu Junfeng Lin Lixia Li Shenzhen Entry-Exit Inspection and Quarantine Bureau Shenzhen China

This paper reported a new analytical method for the simultaneous determination of seven benzotriazole ultraviolet absorbers and seven antibacterial agents in textiles. After ultrasonic extraction for the textile samples in methanol, the solutions were analyzed by ultra-high performance liquid chromotagraphy/orbitrap high resolution mass spectrometry (UPLC/Orbitrap HRMS). It showed that a good chromatographic separation for these target compounds was achieved by a Hypersil GOLD column (100 mm × 2.1 mm × 1.9 μm) with a gradient elution of methanol and 0.1% aqueous formic acid solution (containing 0.5 mmol/L ammonium acetate). Triclosan and 4-chloro-3,5-dimethyl phenol (PCMX) were detected by the orbitrap HRMS in an electrospray ionization (ESI) negative mode while the other twelve target compounds were detected by orbitrap HRMS in ESI positive mode. Full scan experiment was performed over the range from m/z 100 to m/z 500. These target compounds were routinely detected with mass accuracy below 2 × 10-6 (2 ppm) at the optimized conditions. The results showed that the limits of detection (LODs) were in the range from 0.1 to 0.3 μg/kg. The blank samples were spiked at three levels and their average recoveries varied from 80.5% to 96.3% while the relative standard deviation (RSD) changed from 3.2% to 9.9%. The present method was also applied for the determination of those ultraviolet absorbers and antibacterial agents in the commercial textiles.

关键词： Ultra-High Performance Liquid Chromatography/Orbitrap High Resolution Mass Spectrometry Benzotriazoleultraviolet absorbers Isothiazolinone Tric-losan 4-Chloro-3 5-Dimethyl Phenol

Metamaterial absorbers in Terahertz Band

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Journal of Electronic Science and Technology 2013年第4期11卷 360-366页

作者： Qi-Ye Wen Huai-Wu Zhang Qing-Hui Yang Man-Man Mo the State Key Laboratory of Electronic Films and Integrated Devices University of Electronic Science and Technology of China

In recent years, a great deal of effort has been made to a create terahertz （THz） wave absorber based on metamaterials （MM）. Metamaterials absorbers have a variety of potential applications including thermal emitters, detector, stealth technology, phase imaging, etc. In this paper, we firstly introduce the basic structure and work principle of the THz MM absorbers, and a transmission line model is developed for devices analysis. To expand the application of THz absorbers, dual-band and broadband THz MM absorbers are designed, fabricated, and measured. At the end of this article, the future development trends of MM absorbers are discussed.

关键词： absorbers broadband dual-band,metamaterials terahertz transmission line mode.

Rapid Prototyping of Pyramidal Structured absorbers for Ultrasound

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Open Journal of Acoustics 2017年第3期7卷 83-93页

作者： Fabián Acquaticci Maximiliano M. Yommi Sergio N. Gwirc Sergio E. Lew Instituto de Ingeniería Biomédica Universidad de Buenos Aires Buenos Aires Argentina Laboratorio de Transductores Piezoeléctricos Instituto Nacional de Tecnología Industrial Buenos Aires Argentina

Acoustic measurements or ultrasonic testing can be strongly affected by reflections or echoes from test tank walls. In order to create a non-reflecting environment equivalent to infinite medium, a pyramidal structured absorber (PSA) can be used to coat the walls of an ultrasonic tank. In this work, we model an array of tetragonal pyramid ultrasonic wave absorbers. This model is based on two coupled first-order equations describing the stress and particle velocity within an isotropic medium. For absorbing media, the Kelvin-Voigt model of viscoelasticity is used. The equations are discretized in 2D using an efficient time-stepping pseudo-spectral scheme that takes in consideration both, the acoustic properties and attenuation characteristics of the composite materials. We then built a 3D printed PSA using a Stratasys Objet500 Connex 3D printer, which allows to combine photopolymers in specific concentrations and microstructures. We designed PSA covering the frequency ranges from 0.5 MHz to 5 MHz and from 1 MHz to 10 MHz, with double homogeneous layer: a core of rubber material with a skin of a variety of elastomers by combining rigid and flexible materials. Each single pyramid contains two major parts: the ground of the pyramid (9.4 mm base × 4.7 mm height, for 0.5 MHz and 4.7 mm base × 2.35 mm height, for 1 MHz) and the body of the pyramid (23.5 mm height, for 0.5 MHZ and 11.75 mm height, for 1 MHz). The measured echo-reduction was greater than 35 dB at the covering frequency range and the transmission loss was estimated by 20 dB. Echoes increase rapidly for frequencies below the minimum frequency of the covering range. The modeling and 3D printing of PSA with different sizes, in a wide range of frequencies, is a cost-effective custom solution for a wide range of applications including for example, radiation force balances, hydrophone mounts and medical ultrasound equipment.

关键词： Pyramidal absorbers Medical Ultrasonic Measurements Absorbing Targets Anechoic Linings Acoustic Materials

Underwater acoustic metamaterials

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National Science Review 2023年第6期10卷 258-280页

作者： Erqian Dong Peizheng Cao Jinhu Zhang Sai Zhang Nicholas X.Fang Yu Zhang Key Laboratory of Underwater Acoustic Communication and Marine Information Technology of the Ministry of Education College of Ocean and Earth Sciences Xiamen University State Key Laboratory of Marine Environmental Science Xiamen University School of Physics and Electronic Engineering Jiangsu University Department of Mechanical Engineering Massachusetts Institute of Technology

Acoustic metamaterials have been widely investigated over the past few decades and have realized acoustic parameters that are not achievable using conventional *** demonstrating that locally resonant acoustic metamaterials are capable of acting as subwavelength unit cells,researchers have evaluated the possibility of breaking the classical limitations of the material mass density and bulk *** with theoretical analysis,additive manufacturing and engineering applications,acoustic metamaterials have demonstrated extraordinary capabilities,including negative refraction,cloaking,beam formation and super-resolution *** to the complexity of impedance boundaries and mode transitions,there are still challenges in freely manipulating acoustic propagation in an underwater *** review summarizes the developments in underwater acoustic metamaterials over the past 20 years,which include underwater acoustic invisibility cloaking,underwater beam formation,underwater metasurfaces and phase engineering,underwater topological acoustics and underwater acoustic metamaterial *** the evolution of underwater metamaterials and the timeline of scientific advances,underwater acoustic metamaterials have demonstrated exciting applications in underwater resource development,target recognition,imaging,noise reduction,navigation and communication.

关键词： underwater acoustic metamaterials invisibility cloaking beam formation topological acoustics metasurfaces absorbers

Electromagnetic Waves Absorbing Characteristics of Composite Material Containing Carbonyl Iron Particles

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Materials Sciences and Applications 2014年第11期5卷 803-811页

作者： Victor A. Zhuravlev Valentin I. Suslyaev Evgeny Yu. Korovin Kyrill V. Dorozhkin Department of Radioelectronics National Research Tomsk State University Tomsk Russia

Results of measurements of permeability, permittivity and radar absorption properties of composites on basis of carbonyl iron particles R-10 brand are presented in this paper. The calculations and experimental studies have shown that in the super high frequency (SHF) and extremely high frequency (EHF) ranges on the basis of two-layer structures with different content of carbonyl iron particles can create a radar absorbing coatings with a reflectivity of less than -10 dB over a wide bandwidth from 3.1 to 17.1 GHz and from 27 to 37 GHz. Absorbing properties of composites are saved in terahertz frequency range from 250 to 525 GHz.

关键词： Electromagnetic Wave absorbers Radar Absorbing Materials and Coatings Composite Materials Carbonyl Iron Powders Spectrum of Permittivity and Permeability

Passive RFID Tag for Railway Application

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Open Journal of Antennas and Propagation 2018年第2期6卷 15-24页

作者： Shreine Abd El-Rahman Ahmed Attiya Hossam El-Deen Mamoud Hala Abd-El Kader Electronics Research Institute Giza Egypt Shoubra Faculty of Engineering Benha University Cairo Egypt

Passive RFID tags based on narrow band absorbers are proposed for railway applications. The tags consist of absorbing tiles of size 30 × 30 cm2. The de-signs of these narrow band absorbers are presented based on infinite array approximation by using periodic boundary conditions. Then, the radar cross sections (RCS) of finite tiles of these designed absorbers are compared with the corresponding RCS of a conduction plate of the same size of the tiles. The difference between the RCS of the absorbing tiles and the conducting tiles corresponds to the RFID digit “1” or “0”. An experiential verification for a sample of these narrow band absorbers is presented based on measuring a fi-nite tile inside a transverse electromagnetic (TEM) cell. The design of this TEM cell is also discussed in detail.

关键词： RFID Tag TEM Cell absorbers Periodic Structures

Effective Offshore Piling Noise Mitigation in Deep Waters

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Journal of Civil Engineering and Architecture 2018年第9期12卷 662-668页

作者： Karl-Heinz Elmer OffNoise-Solutions GmbH 31535 NeustadtMarktstrasse 5Germany

Underwater noise is a severe annoyance and danger to marine *** innovative HSD(hydro sound damper)leads to an effective general method to reduce underwater *** was developed and patented between 2007 and 2010 by the author to reduce general marine noise and especially offshore piling *** theory and the acoustical background of the new noise mitigation method will be *** systems use nets with gas filled elastic balloons and special PE-foam elements with high dissipative effects to reduce continuous and impact *** resonance frequency of the HSD-elements,the optimum damping rate for impact noise,the distribution and the effective frequency range can be fully *** tests and serial applications in offshore wind farms in Germany and Great Britain demonstrate this new effective way to reduce the very high offshore piling *** systems are very small systems and easy to *** are independent of external air supply,not influenced by tidal currents,not expensive and easy adaptable to different *** noise reductions by HSD systems and bubble curtains are measured by an independent acoustics institute when using the biggest hammers in the *** results between 14 dB(decibels)(SEL—sound exposure level)and more than 27 dB(SEL)are presented and discussed.

关键词： Wind turbines and windfarms transient or impulsive noise scattering resonant absorbers construction noise underwater noise mitigation