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Phase formation analysis of Sn-rich bonding layer by x-ray absorption spectroscopy

AIP Conference Proceedings 2018年第1期2008卷

作者： Chupong Pakpum Kanokwan Kanchiang 1Program in Applied Physics Faculty of Science Maejo University Chiang Mai 50290 Thailand

This work aims to investigate the phase formation of SnAu binary system which is Sn-rich bonding layer of total thickness in order of about 2 μm. Stack of metals layer prepared on silicon were prepared by evaporation technique that compose of Ti/Pt/Au on one side of silicon surface and Ti/Pt/Sn/Au on another side of silicon surface. Both silicon surface was bonded under vacuum pressure with annealing temperature 320°C and 57.5 g bonding force for 30 minutes. A mixing of δ-AuSn, ε−AuSn2 and η-AuSn4 are detected by energy-dispersive x-ray (EDX) micro-analyzer and x-ray absorption spectroscopy (XAS).

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Dynamics of topological solitons, knotted streamlines, and transport of cargo in liquid crystals

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Physical Review E 2018年第5期97卷 052701-052701页

作者： Hayley R. O. Sohn Paul J. Ackerman Timothy J. Boyle Ghadah H. Sheetah Bengt Fornberg Ivan I. Smalyukh Soft Materials Research Center and Materials Science and Engineering Program University of Colorado Boulder Colorado 80309 USA Department of Physics and Department of Electrical Computer and Energy Engineering University of Colorado Boulder Colorado 80309 USA Department of Applied Mathematics University of Colorado Boulder Colorado 80309 USA Renewable and Sustainable Energy Institute National Renewable Energy Laboratory and University of Colorado Boulder Colorado 80309 USA

Active colloids and liquid crystals are capable of locally converting the macroscopically supplied energy into directional motion and promise a host of new applications, ranging from drug delivery to cargo transport at the mesoscale. Here we uncover how topological solitons in liquid crystals can locally transform electric energy to translational motion and allow for the transport of cargo along directions dependent on frequency of the applied electric field. By combining polarized optical video microscopy and numerical modeling that reproduces both the equilibrium structures of solitons and their temporal evolution in applied fields, we uncover the physical underpinnings behind this reconfigurable motion and study how it depends on the structure and topology of solitons. We show that, unexpectedly, the directional motion of solitons with and without the cargo arises mainly from the asymmetry in rotational dynamics of molecular ordering in liquid crystal rather than from the asymmetry of fluid flows, as in conventional active soft matter systems.

关键词： Chirality Topological defects Active nematics Cholesteric liquid crystals Nanoparticles Nematic liquid crystals Soft colloids Solitons

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Multi-frequency effect towards High Conductivity Overburden Responses using Horizontal Coplanar (HCP) coil configuration for Landslide Hazard Instrumentation

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IOP Conference Series: Earth and Environmental Science 2019年第1期273卷

作者： Bukhari Bukhari Muhammad Syukri Surbakti Nazli Ismail Nasrullah Idris Elin Yusibani Muhammad Isa Saumi Syahreza Department of Physics Faculty of Mathematics and Natural Sciences Universitas Syiah Kuala Banda Aceh 23111 Indonesia. Doctorate Program of Mathematics and Applied Science (DMAS) Postgraduate Program Universitas Syiah Kuala Banda Aceh 23111 Indonesia. Tsunami and Disaster Mitigation Research Center (TDMRC) Universitas Syiah Kuala Banda Aceh 23111 Indonesia.

The instrumentation for the sensing of natural disaster phenomena as like as landslide instrumentation has acquired great importance for the instrumentation community. The novel instrumentation for landslide application has been made and calibrated using Horizontal Coplanar (HCP) coil orientation. The early instrumentation for landslide slopes was gradually equipped with standard and automatic instrumentation consisting of three the piezometric cells, two deep-seated steel wire extensometers, four in clinometric tubes, a rainfall gauge, a snow gauge and an air thermometer. This novel instrumentation works in electromagnetic methods similar with electromagnetic methods in geophysics. HCP coil orientation is a coplanar array where both coils are horizontal. In HCP, the depth of sounding is about 1.5 times of the coils separation which have maximum coupled configuration (HCP, VCP, and Vertical Coaxial configuration). The overburden response had inverted the percent value of maximum negative response then there were three maximum response amplitude peaks. Measurement and data processing were performed using a computer through Delphi program. The diagonal cross sections of the overburden as the centre were the maximum value of inverted response of anomaly positions. In aluminium thin plate overburden, the diagonal cross section point as the overburden centre was the maximum value of inverting value of the highest minimum response amplitude. The measurement graphic in the computer screen with several types of overburdens would be displayed. As the result, that the overburden widths for overburden were determined by subtracted of two turning points positions. The overburden positions were accurate for Type P overburden. The master curve had a high anomaly contrasts with two of positive anomaly peaks. Otherwise, the anomaly positions were between two of the negative anomaly peaks.

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Fabrication of ruby by flame fusion technique and their properties

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Materials Today: Proceedings 2018年第7期5卷 15010-15013页

作者： Kitipun Boonin Wichaboon Songpakob Nina Siti Aminah Jakrapong Kaewkhao Applied Physics Program Faculty of Sciences and Technology Suan Sunandha Rajabhat University Bangkok 10300 Thailand Center of Excellence in Glass Technology and Materials Science (CEGM) Nakhon Pathom Rajabhat University Nakhon Pathom 73000 Thailand 13 Charansanitwong 8 Thapra Bangkok 10600 Thailand Faculty of Mathematics and Natural Sciences Institut Teknologi Bandung 40132 Indonesia

In this work, ruby (Cr doped Al 2 O 3 bulk crystal) with the size of ∅10×21 mm was grown by the flame fusion technique (FFT). Absorption spectrum was carried out in the range of 300–800 nm by spectrophotometer, It shows 2 absorption peaks of Cr 3+ in ruby near 400 nm and 550 nm . The crystal structure and the lattice parameters were estimated using X-Ray diffraction studies. The density, refractive index and hardness of synthesis ruby were measured and shown the values in the range of natural ruby material.

关键词： Crystal growth Ruby Optical Hardness

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Deep learning models of the retinal response to natural scenes

arXiv

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arXiv 2017年

作者： McIntosh, Lane T. Maheswaranathan, Niru Nayebi, Aran Ganguli, Surya Baccus, Stephen A. Neurosciences PhD Program Singapore Department of Applied Physics Singapore Neurobiology Department Stanford University United States

A central challenge in sensory neuroscience is to understand neural computations and circuit mechanisms that underlie the encoding of ethologically relevant, natural stimuli. In multilayered neural circuits, nonlinear processes such as synaptic transmission and spiking dynamics present a significant obstacle to the creation of accurate computational models of responses to natural stimuli. Here we demonstrate that deep convolutional neural networks (CNNs) capture retinal responses to natural scenes nearly to within the variability of a cell's response, and are markedly more accurate than linear-nonlinear (LN) models and Generalized Linear Models (GLMs). Moreover, we find two additional surprising properties of CNNs: they are less susceptible to overfitting than their LN counterparts when trained on small amounts of data, and generalize better when tested on stimuli drawn from a different distribution (e.g. between natural scenes and white noise). An examination of the learned CNNs reveals several properties. First, a richer set of feature maps is necessary for predicting the responses to natural scenes compared to white noise. Second, temporally precise responses to slowly varying inputs originate from feedforward inhibition, similar to known retinal mechanisms. Third, the injection of latent noise sources in intermediate layers enables our model to capture the sub-Poisson spiking variability observed in retinal ganglion cells. Fourth, augmenting our CNNs with recurrent lateral connections enables them to capture contrast adaptation as an emergent property of accurately describing retinal responses to natural scenes. These methods can be readily generalized to other sensory modalities and stimulus ensembles. Overall, this work demonstrates that CNNs not only accurately capture sensory circuit responses to natural scenes, but also can yield information about the circuit's internal structure and function. Copyright © 2017, The Authors. All rights reserved.

关键词： Ophthalmology

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Biologically inspired protection of deep networks from adversarial attacks

arXiv

引用

arXiv 2017年

作者： Nayebi, Aran Ganguli, Surya Neurosciences PhD Program Stanford University United States Department of Applied Physics Stanford University United States

Inspired by biophysical principles underlying nonlinear dendritic computation in neural circuits, we develop a scheme to train deep neural networks to make them robust to adversarial attacks. Our scheme generates highly nonlinear, saturated neural networks that achieve state of the art performance on gradient based adversarial examples on MNIST, despite never being exposed to adversarially chosen examples during training. Moreover, these networks exhibit unprecedented robustness to targeted, iterative schemes for generating adversarial examples, including second-order methods. We further identify principles governing how these networks achieve their robustness, drawing on methods from information geometry. We find these networks progressively create highly flat and compressed internal representations that are sensitive to very few input dimensions, while still solving the task. Moreover, they employ highly kurtotic weight distributions, also found in the brain, and we demonstrate how such kurtosis can protect even linear classifiers from adversarial attack. Copyright © 2017, The Authors. All rights reserved.

关键词： Deep neural networks

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Emerging contaminants:A One Health perspective

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The Innovation 2024年第4期5卷 140-170,139页

作者： Fang Wang Leilei Xiang Kelvin Sze-Yin Leung Martin Elsner Ying Zhang Yuming Guo Bo Pan Hongwen Sun Taicheng An Guangguo Ying Bryan WBrooks Deyi Hou Damian EHelbling Jianqiang Sun Hao Qiu Timothy MVogel Wei Zhang Yanzheng Gao Myrna JSimpson Yi Luo Scott XChang Guanyong Su Bryan MWong Tzung-May Fu Dong Zhu Karl JJobst Chengjun Ge Frederic Coulon Jean Damascene Harindintwali Xiankui Zeng Haijun Wang Yuhao Fu Zhong Wei Rainer Lohmann Changer Chen Yang Song Concepcion Sanchez-Cid Yu Wang Ali El-Naggar Yiming Yao Yanran Huang Japhet Cheuk-Fung Law Chenggang Gu Huizhong Shen Yanpeng Gao Chao Qin Hao Li Tong Zhang Natàlia Corcoll Min Liu Daniel SAlessi Hui Li Kristian KBrandt Yolanda Pico Cheng Gu Jianhua Guo Jianqiang Su Philippe Corvini Mao Ye Teresa Rocha-Santos Huan He Yi Yang Meiping Tong Weina Zhang Fidèle Suanon Ferdi Brahushi Zhenyu Wang Syed AHashsham Marko Virta Qingbin Yuan Gaofei Jiang Louis A.Tremblay Qingwei Bu Jichun Wu Willie Peijnenburg Edward Topp Xinde Cao Xin Jiang Minghui Zheng Taolin Zhang Yongming Luo Lizhong Zhu Xiangdong Li DamiàBarceló Jianmin Chen Baoshan Xing Wulf Amelung Zongwei Cai Ravi Naidu Qirong Shen Janusz Pawliszyn Yong-guan Zhu Andreas Schaeffer Matthias C.Rillig Fengchang Wu Gang Yu James M.Tiedje State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil ScienceChinese Academy of SciencesNanjing 210008China University of Chinese Academy of Sciences Beijing 100049China Department of Chemistry Hong Kong Baptist UniversityHong KongChina HKBU Institute of Research and Continuing Education Shenzhen Virtual University ParkShenzhenChina Technical University of Munich TUM School of Natural SciencesInstitute of Hydrochemistry85748 GarchingGermany School of Resources&Environment Northeast Agricultural UniversityHarbin 150030China Climate Air Quality Research UnitSchool of Public Health and Preventive MedicineMonash UniversityMelbourneVICAustralia Faculty of Environmental Science&Engineering Kunming University of Science&TechnologyKunming 650500China Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria College of Environmental Science and EngineeringNankai UniversityTianjin 300350China Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control School of Environmental Science and EngineeringInstitute of Environmental Health and Pollution ControlGuangdong University of TechnologyGuangzhou 510006China Ministry of Education Key Laboratory of Environmental Theoretical Chemistry South China Normal UniversityGuangzhouGuangdong 510006China Department of Environmental Science Baylor UniversityWacoTXUSA Center for Reservoir and Aquatic Systems Research(CRASR) Baylor UniversityWacoTXUSA School of Environment Tsinghua UniversityBeijing 100084China School of Civil and Environmental Engineering Cornell UniversityIthacaNY 14853USA Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province Zhejiang University of TechnologyHangzhou 310014China School of Environmental Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China Laboratoire d’Ecologie Microbienne Universite Claude Bernard Lyon 1UMR CNRS 5557UMR INRAE 1418VetAgro Sup69622 VilleurbanneFrance Department of Pla

Environmental pollution is escalating due to rapid global development that often prioritizes human needs over planetary *** global efforts to mitigate legacy pollutants,the continuous introduction of new substances remains a major threat to both people and the *** response,global initiatives are focusing on risk assessment and regulation of emerging contaminants,as demonstrated by the ongoing efforts to establish the UN’s Intergovernmental Science-Policy Panel on Chemicals,Waste,and Pollution *** review identifies the sources and impacts of emerging contaminants on planetary health,emphasizing the importance of adopting a One Health *** for monitoring and addressing these pollutants are discussed,underscoring the need for robust and socially equitable environmental policies at both regional and international *** actions are needed to transition toward sustainable pollution management practices to safeguard our planet for future generations.

关键词： pollution planet contaminants

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Disorder-driven glasslike thermal conductivity in colusite Cu26V2Sn6S32 investigated by Mössbauer spectroscopy and inelastic neutron scattering

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Physical Review Materials 2020年第2期4卷 025404-025404页

作者： Christophe Candolfi Gabin Guélou Cédric Bourgès Andrew R. Supka Rabih Al Rahal Al Orabi Marco Fornari Bernard Malaman Gérard Le Caër Pierric Lemoine Vincent Hardy Jean-Marc Zanotti Raju Chetty Michihiro Ohta Koichiro Suekuni Emmanuel Guilmeau Institut Jean Lamour UMR 7198 CNRS – Université de Lorraine 2 allée André Guinier-Campus ARTEM BP 50840 54011 Nancy Cedex France Laboratoire CRISMAT UMR 6508 CNRS ENSICAEN 6 Boulevard du Maréchal Juin 14050 Caen Cedex 04 France Department of Physics and Science of Advanced Materials Program Central Michigan University Mt. Pleasant Michigan 48859 United States Solvay Design and Development of Functional Materials Department AXEL’ ONE Collaborative Platform − Innovative Materials 87 Rue des Freres Perret − BP62 69192 Saint Fons Cedex France Institut de Physique de Rennes UMR UR1-CNRS 6251 Université de Rennes I Campus de Beaulieu 35042 Rennes Cedex France Université de Rennes CNRS ISCR – UMR 6226 F-35000 Rennes France Laboratoire Léon Brillouin CNRS-CEA (UMR 12) CNRS Université Paris-Saclay CEA Saclay 91191 Gif-sur-Yvette Cedex France Research Institute for Energy Conservation National Institute of Advanced Industrial Science and Technology (AIST) Tsukuba Ibaraki 305–8568 Japan Department of Applied Science for Electronics and Materials Interdisciplinary Graduate School of Engineering Sciences Kyushu University Kasuga Fukuoka 816–8580 Japan

The influence of structural disorder on the thermal transport in the colusite Cu26V2Sn6S32 has been investigated by means of low-temperature thermal conductivity and specific heat measurements (2–300 K), Sn119 Mössbauer spectroscopy and temperature-dependent powder inelastic neutron scattering (INS). Variations in the high-temperature synthesis conditions act as a key parameter for tuning the degree of disorder in colusite compounds. Intriguingly, we find that all synthesized samples are disordered, the degree of which varies with the synthesis conditions used. Mössbauer data clearly evidence that Sn atoms do not solely occupy the 6c site of the crystal lattice but are present on possibly both the Cu and V sites, leading to a random distribution of these three cations within the unit cell. Increasing the disorder in these materials tends to lead to a smearing out of the main features in the phonon density of states measured by INS. Although the evolution of the inelastic signal upon warming is well described by a quasiharmonic approximation, elastic properties calculations indicate large average Grüneisen parameters, consistent with those determined experimentally from thermodynamic data. Increasing the level of disorder results in a decreased average Grüneisen parameter suggesting that the lowered lattice thermal conductivity is not driven by enhanced anharmonicity. These results provide experimental evidence to support that the remarkable changeover in the lattice thermal conductivity from crystalline to glasslike is solely driven by enhanced disorder accompanied by local lattice distortions.

关键词： Thermal properties Polycrystalline materials Mössbauer spectroscopy Time-of-flight neutron spectroscopy

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A two-point diagnostic for the hii galaxy hubble diagram

arXiv

引用

arXiv 2017年

作者： Leaf, Kyle Melia, Fulvio Department of Physics University of Arizona AZ85721 United States Applied Math Program Department of Physics University of Arizona AZ85721 United States

A previous analysis of starburst-dominated HII Galaxies and HII regions has demonstrated a statistically significant preference for the Friedmann-Robertson-Walker cosmology with zero active mass, known as the Rh = ct universe, over CDM and its related dark-matter parametrizations. In this paper, we employ a 2-point diagnostic with these data to present a complementary statistical comparison of Rh = ct with Planck CDM. Our 2-point diagnostic compares-in a pairwise fashion-the difference between the distance modulus measured at two redshifts with that predicted by each *** results support the conclusion drawn by a previous comparative analysis demonstrating that Rh = ct is statistically preferred over Planck CDM. But we also find that the reported errors in the HII measurements may not be purely Gaussian, perhaps due to a partial contamination by non-Gaussian systematic effects. The use of HII Galaxies and HII regions as standard candles may be improved even further with a better handling of the systematics in these sources. Copyright © 2017, The Authors. All rights reserved.

关键词： Galaxies

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Light Localization in Local Isomorphism Classes of Quasicrystals

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Physical Review Letters 2018年第24期120卷 247401-247401页

作者： Chaney Lin Paul J. Steinhardt Salvatore Torquato Department of Physics Princeton University Princeton New Jersey 08544 USA Princeton Center for Theoretical Science Princeton University Princeton New Jersey 08544 USA Department of Chemistry Princeton University Princeton New Jersey 08544 USA Program of Applied and Computational Mathematics Princeton University Princeton New Jersey 08544 USA Princeton Institute for the Science and Technology of Materials Princeton University Princeton New Jersey 08544 USA

We study a continuum of photonic quasicrystal heterostructures derived from local isomorphism (LI) classes of pentagonal quasicrystal tilings. These tilings are obtained by direct projection from a five-dimensional hypercubic lattice. We demonstrate that, with the sole exception of the Penrose LI class, all other LI classes result in degenerate, effectively localized states, with precisely predictable and tunable properties (frequencies, frequency splittings, and densities). We show that localization and tunability are related to a mathematical property of the pattern known as “restorability,” i.e., whether the tiling can be uniquely specified given only a set of rules that fix all allowed clusters smaller than some bound.

关键词： Photonic crystals Photonics Quasicrystals

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