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Distinguishing Enantiomers by Tip-Enhanced Raman Scattering: Chemically Modified Silver Tip with an Asymmetric Atomic Arrangement

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Angewandte Chemie 2020年第34期132卷 14672-14677页

作者： Sukmanee T. Wongravee K. Kitahama Y. Ekgasit S. Itoh T. Pienpinijtham P. Ozaki Y. Department of Chemistry School of Science and Technology Kwansei Gakuin University 2-1 Gakuen Sanda Hyogo 669-1337 Japan Sensor Research Unit Department of Chemistry Faculty of Science Chulalongkorn University 254 Phayathai Rd. Pathumwan Bangkok 10330 Thailand National Nanotechnology Center of Advanced Structural and Functional Nanomaterials Faculty of Science Chulalongkorn University 254 Phayathai Rd. Pathumwan Bangkok 10330 Thailand National Institute of Advanced Industrial Science and Technology (AIST) Takamatsu Kagawa 761-0395 Japan

Discrimination between enantiomers is achieved by tip-enhanced Raman scattering (TERS) using a silver tip that is chemically modified by an achiral para-mercaptopyridine (pMPY) probe molecule. Differences in the relative intensities of the pMPY spectra were monitored for three pairs of enantiomers containing hydroxy (−OH) and/or amino (−NH2) groups. The N: or N+−H functionality of the pMPY-modified tip participates in hydrogen-bond interactions with a particular molecular orientation of each chiral isomer. The asymmetric arrangement of silver atoms at the apex of the tip induces an asymmetric electric field, which causes the tip to become a chiral center. Differences in the charge-transfer (CT) states of the metal-achiral probe system in conjunction with the asymmetric electric field produce different enhancements in the Raman signals of the two enantiomers. The near-field effect of the asymmetric electric field, which depends on the number of analyte functional groups capable of hydrogen-bond formation, improves the degree of discrimination. © 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

关键词： charge transfer chirality hydrogen bonding Raman spectroscopy silver

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Intra-spectral temperature-compensated FBG sensors for hydrogen detection and beyond

Intra-spectral temperature-compensated FBG sensors for hydro...

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Optica Sensing Congress 2023, AIS, FTS, HISE, sensors, ES 2023 - Part of Optical sensors and Sensing Congress 2023

作者： Buchfellner, F. Bian, Q. Moos, F. Nicolai, J. Zhang, F. Hu, W. Yang, M. Koch, A.W. Roths, J. Photonics Lab. Munich University of Applied Sciences Lothstrasse 34 Munich80335 Germany Institute for Measurement Systems and Sensor Technology Technical University Munich Munich80333 Germany Advanced Photonic Components Lab Carleton University OttawaONK1S 5B6 Canada National Engineering Research Center for Optical Fiber Sensing Technology Wuhan University of Technology Wuhan430070 China

Intra-spectral referencing of the notch to the π-FBG envelope enables direct measurement and compensation of temperature within an FBG element. This enhances reliability and enables versatile real-field applications ... 详细信息

ISBN: (纸本)9781957171241

关键词： Fiber Bragg gratings

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Evaluation of Adjacent and Opposite Current Injection Patterns for 3D Image Reconstruction of the Human Lung Based on a Realistic Model 17

Evaluation of Adjacent and Opposite Current Injection Patter...

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17th International Workshop on Impedance Spectroscopy, IWIS 2024

作者： Bouchhima, Mejda Bader, Oumaima Hafsa, Mariem Sahnoun, Salwa Ben Amara, Najoua Essoukri Kanoun, Olfa National School of Electronics and Telecommunications of Sfax University of Sfax Sfax3038 Tunisia Professorship Measurement and Sensor Technology Chemnitz University of Technology Chemnitz09111 Germany Université de Sousse Ecole Nationale d'Ingénieurs de Sousse LATIS - Laboratory of Advanced Technology and Intelligent Systems Sousse4023 Tunisia Laboratory of Signals Systems Artificial Intelligence and Networks Digital Research Center of Sfax Sfax3038 Tunisia

ISBN: (纸本)9798331507626

Electrical Impedance Tomography (EIT) is a non-invasive, radiation-free imaging technique that can be used for 2D lung imaging. However, 2D EIT has a simplified geometric assumption, which neglects the 3D dynamic lung changes. This study develops a realistic 3D geometrical model including the lungs and thoracic cavity For EIT analysis. Finite Element (FE) models are generated for forward calculation and image reconstruction using an optimized Gauss-Newton (GN) algorithm. Two common current injection patterns - Adjacent and Opposite - are compared. Results show that using the lung-refined model with prior knowledge of the lungs' elements, GN converges with a Pearson correlation (r) of 0.9707 for the opposite pattern, higher than the adjacent pattern which reaches 0.9703. The second metric is the mean squared errors (MSE) between boundary voltages (BV) from reconstructed images and ground truth. It reaches 5.3965 · 10-4,5.3963· 10-4, and 1.0276· 10-12 for the Opposite pattern, respectively, for an empty cavity, lung-refined mesh without, and with prior knowledge of the lungs' elements. The results prove the efficiency of the Opposite injection pattern compared to the Adjacent pattern. These findings highlight the importance of injection patterns and the benefits of using a lung-refined mesh with prior knowledge of the lungs' elements for more accurate reconstructions. © 2024 IEEE.

关键词： Mesh generation

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Highly efficient THz four-wave mixing in doped silicon

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Light(Science & Applications) 2021年第5期10卷 806-811页

作者： Nils Dessmann Nguyen H.Le Viktoria Eless Steven Chick Kamyar Saeedi Alberto Perez-Delgado Sergey G.Pavlov Alexander F.G.van der Meer Konstantin L.Litvinenko Ian Galbraith Nikolay V.Abrosimov Helge Riemann Carl R.Pidgeon Gabriel Aeppli Britta Redlich Benedict N.Murdin Radboud University Institute for Molecules and MaterialsHFML-FELIXNijmegenThe Netherlands Advanced Technology Institute and Department of Physics University of SurreyGuildford GU27XHUK Institute of Optical Sensor Systems German Aerospace CenterBerinGermany Institute of Photonics and Quantum Sciences SUPAHeriot-Watt UniversityEdinburghUK Leibniz-Institut fur Kristallzuchtung(IKZ) BerlinGermany Laboratory for Solid State Physics ETH Zurich8093 ZurichSwitzerland Institut de Physique EPFL1015 LausanneSwitzerland Paul Scherrer Institute 5232 VlligenSwitzerland

Third-order non-linearities are important because they allow control over light pulses in ubiquitous high-quality centro-symmetric materials like silicon and *** four-wave mixing provides a direct measure of the third-order non-linear sheet susceptibility x^(3)(where L represents the material thickness)as well as technological possibilities such as optically gated detection and emission of *** picosecond pulses from a free electron laser,we show that silicon doped with P or Bi has a value of x^(3)Lin the THz domain that is higher than that reported for any other material in any wavelength *** immediate implication of our results is the efficient generation of intense coherent THz light via upconversion(also a x^(3)process),and they open the door to exploitation of nondegenerate mixing and optical nonlinearities beyond the perturbative regime.

关键词： mixing wave Highly

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A frequency-tunable microactuator with a varied comb-width profile

A frequency-tunable microactuator with a varied comb-width p...

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IEEE International Conference on Micro Electro Mechanical Systems

作者： Ki Bang Lee L. Lin Young-Ho Cho Berkeley Sensor and Actuator Center Department of Mechanical Engineering University of California Berkeley Berkeley CA USA Digital Nanolocomotion Center Department of Biosystems Korea Advanced Institute of Science and Technology South Korea

A frequency-tunable microactuator with a varied comb-width profile for electrostatic, post-fabrication frequency tuning has been demonstrated. The theoretical comb-width profile was derived to obtain a constant electrostatic stiffness, independent of the position of the combs. A tunable microactuator, having 186 pairs of the varied comb-width profile, was designed and fabricated by the standard surface micromachining process. Under a biased voltage of 150 V, the resonant frequency was tuned and reduced by 55% from the initial resonant frequency of 19 kHz and the corresponding effective stiffness was decreased 80% from the initial value of 2.64 N/m. As such, this scheme can be applied to comb-shape, electrostatic-based microsensors and microactuators for active frequency tuning applications.

关键词： Microactuators Fingers Electrostatics Voltage control Resonant frequency Tuning Space stations Shape Displacement control Microstructure

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Smoothing The Way Towards Miniaturized MEMS AlN-based Piezoelectric Transformers

Smoothing The Way Towards Miniaturized MEMS AlN-based Piezoe...

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IEEE sensors Conference

作者： Guido Sordo Jacopo Iannacci Michael Schneider Ulrich Schmid Antonio Camarda Marco Tartagni Aldo Romani Center for Materials and MicroSystems - CMM Fondazione Bruno Kessler - FBK Institute of Sensor and Actuator Systems (ISAS) Vienna University of Technology (VUT) Advanced Research Center on Electronics Systems - ARCES University of Bologna

ISBN: (纸本)9781509010134

This work presents the electromechanical characterization and design of a Piezoelectric Transformer (PT) made on a Silicon-On-Insulator (SOI) structure through a bulk micromachining process exploiting low-frequency flexural-modes. The footprint area of the device is less than 3.5 mm~2. The purpose of this work is to show the enhancement obtained with respect to prior state of the art in terms of quality factor and voltage gain for the fundamental mode. As matter of fact, the presented device, achieves Q-factor ～71 at environmental pressure, being almost 6 times greater with respect to the one of the same membrane with double radius and almost 4X footprint area. The step-up ratio at environmental pressure is ～25mV/V, but it increases at 250mV/V when the device is operated in a vacuum chamber, thus being more than 20X times higher the step-up ratio achieved for the same membrane with double radius in vacuum environment.

关键词： Aluminum Nitride Butterworth-Van Dyke circuit Flexure-mode Membrane MEMS Piezoelectric Transformer aluminum nitrides Microelectromechanical systems membrane step-up ratio Transformer Quality factor state of the art Voltage gain environmental pressure fundamental mode silicon-on-insulator

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A Hybrid Biofuel and Triboelectric Nanogenerator for Bioenergy Harvesting

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Nano-Micro Letters 2020年第4期12卷 53-64页

作者： Hu Li Xiao Zhang Luming Zhao Dongjie Jiang Lingling Xu Zhuo Liu Yuxiang Wu Kuan Hu Ming‑Rong Zhang Jiangxue Wang Yubo Fan Zhou Li Beijing Advanced Innovation Centre for Biomedical Engineering Key Laboratory for Biomechanics and Mechanobiology of Chinese Education MinistrySchool of Biological Science and Medical EngineeringBeihang UniversityBeijing 100083People’s Republic of China CAS Center for Excellence in Nanoscience Beijing Key Laboratory of Micro‑Nano Energy and SensorBeijing Institute of Nanoenergy and NanosystemsChinese Academy of SciencesBeijing 100083People’s Republic of China School of Nanoscience and Technology University of Chinese Academy of SciencesBeijing 100049People’s Republic of China School of Physical Education Jianghan UniversityWuhan 430056People’s Republic of China Center on Nanoenergy Research School of Physical Science and TechnologyGuangxi UniversityNanning 530004People’s Republic of China Department of Radiopharmaceuticals Development National Institute of Radiological SciencesNational Institutes for Quantum and Radiological Science and TechnologyChiba 263‑8555Japan

Various types of energy exist everywhere around us,and these energies can be harvested from multiple sources to power micro-/nanoelectronic system and even personal electronic *** this work,we proposed a hybrid energy-harvesting system(HEHS)for potential in vivo *** HEHS consisted of a triboelectric nanogenerator and a glucose fuel cell for simultaneously harvesting biomechanical energy and biochemical energy in simulated body *** two energy-harvesting units can work individually as a single power source or work simultaneously as an integrated *** design strengthened the flexibility of harvesting multiple energies and enhanced corresponding electric *** with any individual device,the integrated HEHS outputs a superimposed current and has a faster charging *** the harvested energy,HEHS can power a calculator or a green light-emitting diode *** the widely existed biomechanical energy and glucose molecules in the body,the developed HEHS can be a promising candidate for building in vivo self-powered healthcare monitoring system.

关键词： Self-powered Triboelectric nanogenerator Glucose fuel cell Hybrid energy harvester Bioenergy

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Probabilistic neural network based olfactory classification for household burning in early fire detection application

Probabilistic neural network based olfactory classification ...

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IEEE Conference on Open Systems (ICOS)

作者： A.M. Andrew K. Kamarudin S.M. Mamduh A.Y.M. Shakaff A. Zakaria A.H. Adom D.L. Ndzi S. Ragunathan Centre of Excellence for Advanced Sensor Technology (CEASTech) University of Malaysia Perlis (UniMAP) Arau Perlis MALAYSIA Center of Excellence Geopolymer and Green Technology (CEGeoGtech) Universiti Malaysia Perlis (UniMAP) Kangar Perlis MALAYSIA

Determination of burning smell is important because it can help in early fire detection and prevention. In this paper, a household burning smell classification system for early fire detection application has been proposed using Probabilistic Neural Network (PNN) and PCA analysis. The experiments were performed on recorded smell samples from combustion of ten different commonly available household, including candle, joss sticks, air freshener, mosquito coil, newspaper, card board, plastic materials, Styrofoam and wood. All the experiments were done in a test chamber with humidity and temperature sensors. Portable Electronic Nose (PEN3) from Airsense Analytics is used as the measurement device. The smell source is placed 0.3m from the PEN3 and the time-series signal is measured for two minutes. The odour metrics is modelled using Probabilistic Neural Network. It is found that the average classification accuracy for the model is 99.62%.

关键词： Monitoring Biomedical monitoring Educational institutions Atmospheric measurements Particle measurements Materials Communication cables

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A Review: Deep Learning Classification Performance of Normal and COVID-19 Chest X-ray Images

A Review: Deep Learning Classification Performance of Normal...

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2021 International Conference on Biomedical Engineering, ICoBE 2021

作者： Markom, M.A. Taha, S. Mohd Adom, A.H. Sukor, A.S. Abdull Nasir, A.S. Abdul Yazid, H. Tan, E.S.M.M. Markom, A.M. Advanced Sensor Technology Center of Excellence Universiti Malaysia Perlis Arau Perlis 02600 Malaysia Faculty of Electronic Engineering Technology Universiti Malaysia Perlis Arau Perlis 02600 Malaysia Faculty of Electric Engineering Technology Universiti Malaysia Perlis Arau Perlis 02600 Malaysia Faculty of Mechanical Engineering Technology Universiti Malaysia Perlis Arau Perlis 02600 Malaysia Universiti Teknologi MARA Cawangan Johor Kampus Pasir Gudang Jalan Purnama Bandar Seri Alam Masai Johor81750 Malaysia

COVID19 chest X-ray has been used as supplementary tools to support COVID19 severity level diagnosis. However, there are challenges that required to face by researchers around the world in order to implement these chest X-ray samples to be very helpful to detect the disease. Here, this paper presents a review of COVID19 chest X-ray classification using deep learning approach. This study is conducted to discuss the source of images and deep learning models as well as its performances. At the end of this paper, the challenges and future work on COVID19 chest X-ray are discussed and proposed. © 2021 Institute of Physics Publishing. All rights reserved.

关键词： Image classification

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A wearable noncontact free-rotating hybrid nanogenerator for self-powered electronics

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InfoMat 2020年第6期2卷 1191-1200页

作者： Dongjie Jiang Han Ouyang Bojing Shi Yang Zou Puchuan Tan Xuecheng Qu Shengyu Chao Yuan Xi Chaochao Zhao Yubo Fan Zhou Li CAS Center for Excellence in Nanoscience Beijing Key Laboratory of Micro-nano Energy and SensorBeijing Institute of Nanoenergy and NanosystemsChinese Academy of SciencesBeijingChina Beijing Advanced Innovation Centre for Biomedical Engineering Key Laboratory for Biomechanics and Mechanobiology of Ministry of EducationSchool of Biological Science and Medical EngineeringBeihang UniversityBeijingChina School of Nanoscience and Technology University of Chinese Academy of SciencesBeijingChina Department of Biomedical Engineering School of Medical EngineeringFoshan UniversityFoshanChina

Self-powerability is a new trend in the development of portable *** biomechanical energy to power personal information electronics is of great *** this work,we report a wearable noncontact freerotating hybrid nanogenerator(WRG),which is constituted by a triboelectric nanogenerator and an electromagnetic generator.A continuous output over 2 seconds can be achieved during one instantaneous incentive by external force,which is improved by two orders of magnitude compared to other wearable nanogenerators due to its unique mechanical energy storage *** WRG can be integrated into shoes to generate an output energy of 14.68 mJ in each stepping,which meets the power requirements of most personal information *** wireless sensor,GPS,and smartphone can be powered by the WRG *** WRG is expected to be applied in self-powered information electronics extensively in the future.

关键词： electromagnetic generator hybrid nanogenerator self-powered electronics triboelectric nanogenerator wearable electronics

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