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Chinese Science Bulletin 1989年第5期34卷 356-360页

作者：郭聿琦 C.M.REIS g.THIERRIN Lanzhou University University of Western Ontario

Ⅰ. INTROOUCTIONLet X be a nonempty finite set called an alphabet, and X~* the free monoid generated by X and X^+=X~*—{1}, where 1 is the identity of X~* called the empty word over X. Elements and subsets of X~* are called words and languages over X respectively. The length of a word x which is the number of the letters occurring in x will be denoted by lg(x).

关键词： fd-domain rf-disjunctive language uniformly dense language.

ADER Methods for Hyperbolic Equations with a Time-Reconstruction Solver for the generalized Riemann Problem: the Scalar Case

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Communications on Applied Mathematics and Computation 2020年第3期2卷 369-402页

作者： R.Demattè V.A.Titarev g.I.Montecinos E.F.Toro Department of Aerospace Science and Technology Politecnico di MilanoMilanItaly Dorodnicyn Computing Center Federal Research Center Computer Science and ControlRussianAcademy of SciencesMoscowRussia Departamento de Ciencias Naturales y Tecnología Universidad de AysénCoyhaiqueChile Laboratory of Applied Mathematics DICAMUniversity of TrentoTrentoItaly

The ADER approach to solve hyperbolic equations to very high order of accuracy has seen explosive developments in the last few years,including both methodological aspects as well as very ambitious *** spite of methodological progress,the issues of efficiency and ease of implementation of the solution of the associated generalized Riemann problem(gRP)remain the centre of attention in the ADER *** the original formulation of ADER schemes,the proposed solution procedure for the gRP was based on(i)Taylor series expansion of the solution in time right at the element interface,(ii)subsequent application of the Cauchy-Kowalewskaya procedure to convert time derivatives to functionals of space derivatives,and(iii)solution of classical Riemann problems for high-order spatial derivatives to complete the Taylor series *** realistic problems the Cauchy-Kowalewskaya procedure requires the use of symbolic manipulators and being rather cumbersome its replacement or simplification is highly *** this paper we propose a new class of solvers for the gRP that avoid the Cauchy-Kowalewskaya procedure and result in simpler ADER *** is achieved by exploiting the history of the numerical solution that makes it possible to devise a time-reconstruction procedure at the element *** relying on a time Taylor series expansion of the solution at the interface,the time derivatives are then easily calculated from the time-reconstruction *** resulting schemes are called ADER-TR.A thorough study of the linear stability properties of the linear version of the schemes is carried out using the von Neumann method,thus deducing linear stability ***,via careful numerical experiments,we deduce stability regions for the corresponding non-linear *** examples using the present simplified schemes of fifth and seventh order of accuracy in space and time show that these compare favourably with conventional ADER ***

关键词： Hyperbolic equations Finite volume ADER methods generalized Riemann problem(gRP) Time-reconstruction(TR)

Influence of process parameters on physical dimensions of AA6063 aluminium alloy coating on mild steel in friction surfacing

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Defence Technology（防务技术） 2015年第3期11卷 275-281页

作者： B.VIJAYA KUMAR g.MADHUSUDHAN REDDY T.MOHANDAS Department of Mechanical Engineering Guru Nanak Institute of Technology Defence Metallurgical Research Laboratory Department of Mechanical Engineering Nalla Malla Reddy Engineering College

An attempt is made in the present study to obtain the relationships among process parameters and physical dimensions of AA6063 aluminium alloy coating on IS2062 mild steel obtained through friction surfacing and their impact on strength and ductility of the coating. Factorial experimental design technique was used to investigate and select the parameter combination to achieve a coating with adequate strength and ductility. Spindle speed, axial force and table traverse speed were observed to be the most significant factors on physical dimensions. It was observed that the thickness of the coating decreased as the coating width increased. In addition, the width and thickness of the coatings are higher at low and high torques. At intermediate torque values, when the force is high, the width of the coating is high, and its thickness is thin; and when the force is low, the width and thickness are low. The interaction effect between axial force(F)-table traverse speed(Vx) and spindle speed(N)-table traverse speed(Vx) produced an increasing effect on coating width and thickness, but other interactions exhibited decreasing influence. It has also been observed that sound coatings could be obtained in a narrow set of parameter range as the substrate-coating materials are metallurgically incompatible and have a propensity to form brittle intermetallics.

关键词：合金涂层摩擦表面尺寸物理工艺参数碳钢涂层厚度试验设计技术

Visible light communication with efficient far-red/near-infrared polymer light-emitting diodes

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Light(Science & Applications) 2020年第1期9卷 1362-1372页

作者： Alessandro Minotto Paul A.Haigh Łukasz g.Lukasiewicz Eugenio Lunedei Daniel T.gryko Izzat Darwazeh Franco Cacialli Department of Physics and Astronomy and London Centre for Nanotechnology University College LondonLondon WC1E 6BTUK School of Engineering Newcastle UniversityNewcastle-upon-Tyne NE17RUUK Communications and Information Systems University College LondonLondon WC1E 6BTUK Institute of Organic Chemistry Polish Academy of Sciences01-224 WarsawPoland ISMN-CNR Institute for the Study of Nanostructured Materials40129 BolognaItaly

Visible light communication(VLC)is a wireless technology that relies on optical intensity modulation and is potentially a game changer for internet-of-things(IoT)***,VLC is hindered by the low penetration depth of visible light in non-transparent *** solution is to extend operation into the“nearly(in)visible”near-infrared(NIR,700-1000 nm)region,thus also enabling VLC in photonic bio-applications,considering the biological tissue NIR semitransparency,while conveniently retaining vestigial red emission to help check the link operativity by simple eye ***,we report new far-red/NIR organic light-emitting diodes(OLEDs)with a 650-800 nm emission range and external quantum efficiencies among the highest reported in this spectral range(>2.7%,with maximum radiance and luminance of 3.5 mW/cm^(2) and 260 cd/m^(2),respectively).With these OLEDs,we then demonstrate a“real-time”VLC setup achieving a data rate of 2.2 Mb/s,which satisfies the requirements for IoT and biosensing *** are the highest rates ever reported for an online unequalised VLC link based on solution-processed OLEDs.

关键词： communication diodes IoT

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全绝缘自支撑电缆系统设计(英文)

高电压技术 2011年第11期37卷 2715-2720页

作者： george g.Karady Kumaraguru Prabakar School of Electrical Computer and Energy Engineering Arizona State UniversityTempeArizona

All-dielectric self-supporting(ADSS) cables are installed along with transmission line for the purpose of *** installation the outer layer of the cable is hydrophobic and is not prone to dry band arcing. These cables become less hydrophobic over time and become vulnerable to dry band *** loss in hydrophobicity is because of the contamination formed on the outer layer due to *** is one of the reasons which cause cable *** amount of losses will be incurred on the occurrence of a cable failure as the cables are also leased to other *** improved equivalent circuit is used to calculate the voltage and current distribution of the double circuit line.A three-phase single circuit line and a three-phase double circuit line are used to calculate their corresponding voltage distribution and current *** results could be used to predict dry band arcing on similar *** method used considers sag,span and pollution on ADSS cable.

关键词： dry band arcing all-dielectric self-supporting cable fiber optic cable voltage distribution current distribution all-dielectric self-supporting circuit simulation

Fiber gas sensor-integrated smart face mask for roomtemperature distinguishing of target gases

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Nano Research 2018年第1期11卷 511-519页

作者： Zhiyi gao Zhoe n g Lou Shuai Chen La Li Kai Jiang Zuoling Fu Wei Han guozhen Shen Coherent Light and Atomic and Molecular Spectroscopy Laboratory Key Laboratory of Physics and Technology for Advanced Batteries College of Physics Jilin University Changchun 130012 China State Key Laboratory for Superlattices and Microstructures Institute of Semiconductors Chinese Academy of Sciences Beijing 100083 China Institute & Hospital of Hepatobiliary Surgery Key Laboratory of Digital Hepatobiliary Surgery of Chinese PLA Chinese PLA Medical School Chinese PLA General Hospital Beijing 100853 China Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education)-Intemational Center of Future Science Jilin University Changchun 130012 China College of Materials Science and Opto-electronic Technology University of Chinese Academy of Sciences Beijing 100029 China

Wearable gas sensors that are lightweight, portable, and inexpensive have great potential application in the real-time detection of human health and environmental monitoring. In this work, we fabricated flexible fiber gas sensors with single-walled carbon nanotube （SWCNT）, multi-walled carbon nanotube （MWCNT）, and ZnO quantum dot-decorated SWCNT （SWCNTs@ZnO） sensing elements. These flexible fiber gas sensors could be operated at room temperature to detect target gases with good sensitivity and recovery time. They also exhibited superior long-term stability, as well as good device mechanical bending ability and robustness. Integrating these flexible gas sensors into face masks, the fabricated wearable smart face masks could be used to selectively detect CaHsOH, HCHO, and NH3 by reading the corresponding LEDs with different colors. Such face masks have great potential application in the Internet of Things and wearable electronics.

关键词： wearable electronics gas sensors flexible fiber devices

硅甲基接枝改性MCM-48的结构特征及表面性质

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无机化学学报 2002年第9期18卷 879-886页

作者：杨佳何静段雪 EvansD.g. 北京化工大学可控化学反应科学与技术基础教育部重点实验室北京100029

本文利用三甲基氯硅烷与未焙烧MCM-48反应,实现对MCM-48的表面硅甲基接枝改性。结果表明:原未焙烧MCM-48孔道内的CTAB模板剂被脱除,三甲基氯硅烷与表面羟基反应,将硅甲基官能团接枝到MCM-48的内外表面。改性后MCM-48具有良好的长程有序... 详细信息

本文利用三甲基氯硅烷与未焙烧MCM-48反应,实现对MCM-48的表面硅甲基接枝改性。结果表明:原未焙烧MCM-48孔道内的CTAB模板剂被脱除,三甲基氯硅烷与表面羟基反应,将硅甲基官能团接枝到MCM-48的内外表面。改性后MCM-48具有良好的长程有序结构,较窄的孔径分布,较大的孔体积和较高的比表面积,相对于未焙烧MCM-48,硅甲基接枝改性MCM-48的表面亲水性降低,亲油性得到提高。

关键词：硅甲基接枝改性结构特征表面性质 MCM-48 分子筛孔径分布亲水性表面改性

Seismic performance and global ductility of RC frames rehabilitated with retrofi tted joints by CFRP laminates

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Earthquake Engineering and Engineering Vibration 2014年第1期13卷 59-73页

作者： M.Fakharifar M.K. Sharbatdar Z.Lin A.Dalvand A.Sivandi-Pour g.Chen Department of Civil Architectural and Environmental EngineeringMissouri University of Science and Technology Department of Civil Engineering Semnan University Department of Civil and Environmental Engineering North Dakota State University

This paper presents a new FRP retrofi tting scheme to strengthen local beam-column joints in reinforced concrete(RC) *** new retrofi tting scheme was proposed following a preliminary study of four different existing retrofi tting schemes.A numerical simulation was conducted to evaluate the effectiveness of FRP-strengthened reinforced concrete frames by bridging behavior of local joints to the whole *** confi nement effects due to varying retrofi tting schemes in the joints were simulated in the frame *** seismic behavior factor was used to evaluate the seismic performance of the strengthened RC *** results demonstrated that the new proposed retrofi tting scheme was robust and promising,and fi nite element analysis appropriately captured the strength and global ductility of the frame due to upgrading of the local joints.

关键词： beam-column joints behavior factor retrofit FRP dynamic analysis seismic performance

Computational synthesis of substrates by crystal cleavage

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npj Computational Materials 2021年第1期7卷 1336-1341页

作者： Joshua T.Paul Alice galdi Christopher Parzyck Kyle M.Shen Jared Maxson Richard g.Hennig Department of Materials Science and Engineering University of FloridaGainesvilleFLUSA Quantum Theory Project University of FloridaGainesvilleFLUSA Department of Physics Cornell UniversityIthacaNYUSA Cornell Laboratory for Accelerator-Based Sciences and Education Cornell UniversityIthacaNYUSA

The discovery of substrate materials has been dominated by trial and error,opening the opportunity for a systematic *** generate bonding networks for materials from the Materials Project and systematically break up to three bonds in the networks for three-dimensional *** cleavage reduces the bonding network to two periodic *** identify 4693 symmetrically unique cleavage surfaces across 2133 bulk crystals,4626 of which have a maximum Miller index of *** characterize the likelihood of cleavage by creating monolayers of these surfaces and calculating their thermodynamic stability using density functional theory to discover 3991 potential ***,we identify distinct trends in the work of cleavage and relate them to bonding in the three-dimensional *** illustrate the potential impact of the substrate database by identifying several improved epitaxial substrates for the transparent conductor *** open-source databases of predicted and commercial substrates are available at ***.

关键词： cleavage bonding synthesis