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Urban Physics： Effect of the micro-climate on comfort, health and energy demand

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Frontiers of Architectural Research 2012年第3期1卷 197-228页

作者： Peter Moonen Thijs Defraeye Viktor Dorer Bert Blocken Jan Carmeliet ETH Swiss Federal Institute of Technology Zurich ZUrich Switzerland Empa Swiss Federal Laboratories for Materials Science and Technology KUL Katholieke Universiteit Leuven Leuven Belgium TU/e Eindhoven University of Technology Eindhoven The Netherlands

The global trend towards urbanisation explains the growing interest in the study of the modification of the urban climate due to the heat island effect and global warming, and its impact on enersy use of buildings. Also urban comfort, health and durability, referring respectively to pedestrian wind/ thermal comfort, pollutant dispersion and wind-driven rain are of interest. Urban Physics is a well- established discipline, incorporating relevant branches of physics, environmental chemistry, aerodynamics, meteorolosy and statistics. Therefore, Urban Physics is well positioned to provide keycontributions to the current urban problems and challenges. The present paper addresses the role of Urban Physics in the study of wind comfort, thermal comfort, energy demand, pollutant dispersion and wind-driven rain. Furthermore, the three major research methods applied in Urban Physics, namely field experiments, wind tunnel experiments and numerical simulations are discussed. Case studies illustrate the current challenges and the relevant contributions of Urban Physics.

关键词： Fietd experiments Wind tunnet experi-ments Nurnerical simutations Computationat fluiddynamics (CFD) Wind comfort Thermal comfort Energy demand Pollutant dispersion Wind-driven rain

Fusion and one-neutron stripping process for 6Li+94Zr system around the Coulomb Barrier

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Chinese Physics C 2024年第9期 137-145页

作者：苏学斗张广鑫胡世鹏温琣威 H.O.Soler 张高龙蔡博帅袁岑溪 J.L.Ferreira 焦振威王明李汪小雨黄珍张焕乔张春雷吴晓光郑云李聪博李天晓 J.Lubian School of Physics Beihang University Sino-French Institute of Nuclear Engineering and technology Sun Yat-sen University Institute for Advanced Study in Nuclear Energy & Safety Shenzhen University Shenzhen Key Laboratory of Research and Manufacture of High Purity Germanium materials and Fetectors Shenzhen University China Institute of Atomic Energy Instituto de Física Universidade Federal Fluminense State Key Laboratory of Radiation Medicine and Protection School of Radiation Medicine and ProtectionSoochow University The Key Laboratory of Beam technology and Material Modification of Ministry of Education College of Nuclear Science and Technology Beijing Normal University

The complete and incomplete fusion cross section as well as one-neutron stripping process of6Li+94Zr system were measured at the energies around the Coulomb barrier by online γ-ray *** addition to a 30% suppression factor when compared with the measured total fusion process,the complete fusion cross section in 6Li+94Zr system was observed to be significantly lower than those in the nearby6Li+90,96Zr *** new experimental result implies that the coupling with breakup channel in the 6Li-induced fusion processes can be affected by the inner structure of the target,which is still not clear in any available model *** the one-neutron stripping process,the direct production cross sections for each level in 95Zr were extracted and compared with the coupled reaction channel calculation,offering a unique opportunity to examine the single-particle nature of the produced excited *** the fact that an overall overestimation of the production cross section for 954-keV and1618-keV levels was observed in the comparison,further investigation is highly demanded in order to understand the full reaction mechanism for the one-neutron stripping process induced by6Li.

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Molecular heterostructure by fusing graphene nanoribbons of different lengths through a pentagon ring junction

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Nano Research 2022年第9期15卷 8465-8469页

作者： Qiang Sun Hao Jiang Yuyi Yan Roman Fasel Pascal Ruffieux materials Genome Institute Shanghai UniversityShanghai 200444China Empa Swiss Federal Laboratories for Materials Science and TechnologyDübendorf 8600Switzerland Department of Chemistry Biochemistry and Pharmaceutical SciencesUniversity of BernBern 3012Switzerland

Graphene nanoribbons(GNRs)have attracted great research interest because of their widely tunable and unique electronic *** required atomic precision of GNRs can be realized via on-surface synthesis *** this work,through a surface assisted reaction we have longitudinally fused the pyrene-based graphene nanoribbons(pGNR)of different lengths by a pentagon ring junction,and built a molecular junction structure on Au(111).The electronic properties of the structure are studied by scanning tunneling spectroscopy(STS)combined with tight binding(TB)*** pentagon ring junction shows a weak electronic coupling effect on graphene nanoribbons,which makes the electronic properties of the two different graphene nanoribbons connected by a pentagon ring junction analogous to type I semiconductor heterojunctions.

关键词： graphene nanoribbons(GNRs) scanning tunneling spectroscopy(STS) non-contact atomic force microscopy(nc-AFM) tight-binding(TB)calculations junction structure

Porous and Ultra-Flexible Crosslinked MXene/Polyimide Composites for Multifunctional Electromagnetic Interference Shielding

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Nano-Micro Letters 2022年第4期14卷 59-74页

作者： Zhi-Hui Zeng Na Wu Jing-Jiang Wei Yun-Fei Yang Ting-Ting Wu Bin Li Stefanie Beatrice Hauser Wei-Dong Yang Jiu-Rong Liu Shan-Yu Zhao Key Laboratory for Liquid-Solid Structural Evolution and Processing of materials Ministry of Education and School of Materials Science and EngineeringShandong UniversityJinan 250061People’s Republic of China Department of Chemistry and Applied Biosciences ETH ZurichCH-8093 ZurichSwitzerland Laboratory for Cellulose and Wood materials Swiss Federal Laboratories for Materials Science and Technology(Empa)8600 DübendorfSwitzerland Laboratory for Building Energy materials and Components Swiss Federal Laboratories for Materials Science and Technology(Empa)8600 DübendorfSwitzerland School of Aerospace Engineering and Applied Mechanics Tongji UniversityShanghai 200092People’s Republic of China

Lightweight,ultra-flexible,and robust crosslinked transition metal carbide(Ti3C2 MXene)coated polyimide(PI)(C-MXene@PI)porous composites are manufactured via a scalable dip-coating followed by chemical crosslinking *** addition to the hydrophobicity,anti-oxidation and extreme-temperature stability,efficient utilization of the intrinsic conductivity of MXene,the interfacial polarization between MXene and PI,and the micrometer-sized pores of the composite foams are ***,the composites show a satisfactory X-band electromagnetic interference(EMI)shielding effectiveness of 22.5 to 62.5 dB at a density of 28.7 to 48.7 mg cm−3,leading to an excellent surface-specific SE of 21,317 dB cm^(2)g^(−1).Moreover,the composite foams exhibit excellent electrothermal performance as flexible heaters in terms of a prominent,rapid reproducible,and stable electrothermal effect at low voltages and superior heat performance and more uniform heat distribution compared with the commercial heaters composed of alloy ***,the composite foams are well attached on a human body to check their electromechanical sensing performance,demonstrating the sensitive and reliable detection of human motions as wearable *** excellent EMI shielding performance and multifunctionalities,along with the facile and easy-to-scalable manufacturing techniques,imply promising perspectives of the porous C-MXene@PI composites in next-generation flexible electronics,aerospace,and smart devices.

关键词： MXene Polyimide Electromagnetic interference shielding Heater Sensor

Identification of abnormal tribological regimes using a microphone and semi-supervised machine-learning algorithm

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Friction 2022年第4期10卷 583-596页

作者： Vigneashwara PANDIYAN Josef PROST Georg VORLAUFER Markus VARGA Kilian WASMER Laboratory for Advanced materials Processing(LAMP) Swiss Federal Laboratories for Materials Science and Technology(Empa)Thun CH-3602Switzerland AC2T research GmbH Viktor-Kaplan-Straße 2/CWiener Neustadt 2700Austria

Functional surfaces in relative contact and motion are prone to wear and tear,resulting in loss of efficiency and performance of the workpieces/*** occurs in the form of adhesion,abrasion,scuffing,galling,and scoring between ***,the rate of the wear phenomenon depends primarily on the physical properties and the surrounding *** the integrity of surfaces by offline inspections leads to significant wasted machine time.A potential alternate option to offline inspection currently practiced in industries is the analysis of sensors signatures capable of capturing the wear state and correlating it with the wear phenomenon,followed by in situ classification using a state-of-the-art machine learning(ML)*** this technique is better than offline inspection,it possesses inherent disadvantages for training the ML ***,supervised training of ML models requires the datasets considered for the classification to be of equal weightage to avoid *** collection of such a dataset is very cumbersome and expensive in practice,as in real industrial applications,the malfunction period is minimal compared to normal ***,classification models would not classify new wear phenomena from the normal regime if they are *** a promising alternative,in this work,we propose a methodology able to differentiate the abnormal regimes,i.e.,wear phenomenon regimes,from the normal *** is carried out by familiarizing the ML algorithms only with the distribution of the acoustic emission(AE)signals captured using a microphone related to the normal *** a result,the ML algorithms would be able to detect whether some overlaps exist with the learnt distributions when a new,unseen signal *** achieve this goal,a generative convolutional neural network(CNN)architecture based on variational auto encoder(VAE)is built and *** the validation procedure of the proposed CNN architectures,we were

关键词： surface integrity acoustic emission auto encoders condition monitoring wear prediction

Renewable Polymers in Biomedical Applications:From the Bench to the Market

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Journal of Renewable materials 2024年第4期12卷 643-666页

作者： Rauany Cristina Lopes Tamires Nossa Wilton Rogério Lustri Gabriel Lombardo Maria Inés Errea Eliane Trovatti Department of Health and Biological sciences University of Araraquara—UNIARAAraraquara14801-340Brazil Laboratory of materials(LabMat)and Laboratory of Biopolymers(LaBioPol) Federal Institute of EducationScience and Technology of São Paulo Campus Itapetininga(IFSP)Itapetininga18.202‑000Brazil Instituto Tecnológico de Buenos Aires Cidade Autônoma de Buenos AiresC1437FBCArgentina Conselho Nacional de Pesquisas Científicas e Técnicas(CONICET) Cidade Autônoma de Buenos AiresC1425FQBArgentina Tecnologia YPF(Y-TEC) BerissoBuenos Aires1923Argentina

Polymers from renewable resources have been used for a long time in biomedical applications and found an irreplaceable role in some of *** uses have been increasing because of their attractive properties,contributing to the improvement of life quality,mainly in drug release systems and in regenerative *** using natural polymer,nano and microscale particles preparation,composites,blends and chemical modification strategies have been used to improve their properties for clinical *** many studies have been carried out with these natural polymers,the way to reach the market is long and only very few of them become commercially *** cellulose,bacterial cellulose,chitosan,poly(lactic acid)and starch can be found among the most studied polymers for biological applications,some with several derivatives already established in the market,and others with potential for *** this scenario this work aims to describe the properties and potential of these renewable polymers for biomedical applications,the routes from the bench to the market,and the perspectives for future developments.

关键词： Polymers renewable biomedical applications market

Synthesis and Thermal Insulation Performance of Silica Aerogel from Recycled Coal Gangue by Means of Ambient Pressure Drying

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Journal of Wuhan University of technology(materials science) 2015年第5期30卷 908-913页

作者：朱平华 ZHENG Meng 赵善宇 WU Junyong 徐海珣 School of Environmental and Safety Engineering Changzhou University swiss federal Institute for materials science

Silica aerogel materials are well recognized for their superinsulation performance and are regarded as one of the hot candidates to revolutionize building insulation. To date, high production cost related to exorbitant precursors as well as cumbrous multi-step hydrophobization process has often narrowed the field of applications. In this work, granular silica aerogel materials were synthesized by extracting Si O2 from recycled rich silicon coal gangue, followed by one-step hydrophobization and ambient pressure drying. Lightweight(about 0.16 g/cm3) and nanostructural aerogels were obtained through this route. They exhibit a 3D open porous microstructure with around 600 cm2/g surface area and 20 nm of the average pore diameter, thermal conductivity of 4-5 mm packed granules is 20-25 m W/(m·K), which was proved by both guarded hot plate and hot-wire transient methods. This study offers a new facile route for the synthesis of silica aerogel from recycled solid waste coal gangue and suggests a method, which may lead to a cost reduction in terms of industrial production.

关键词： silica aerogel coal gangue thermal insulation one-step hydrophobization

Phase composition,conductivity,and sensor properties of cerium-doped indium oxide

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Nano materials science 2024年第2期6卷 193-200页

作者： M.I.Ikim G.N.Gerasimov V.F.Gromov O.J.Ilegbusi L.I.Trakhtenberg N.N.Semenov federal Research Center for Chemical Physics of RAS MoscowRussia University of Central Florida OrlandoFLUSA Moscow Institute of Physics and technology(State University) DolgoprudnyMoscow RegionRussia Lomonosov Moscow State University MoscowRussia

The hydrothermal synthesis of In_(2)O_(3)and CeO_(2)–In_(2)O_(3)is investigated as well as the properties of sensor layers based on these *** the synthesis of In_(2)O_(3),intermediate products In(OH)_(3)and InOOH are formed,which are the precursors of stable cubic(c-In_(2)O_(3))and metastable rhombohedral(rh-In_(2)O_(3))phases,respectively.A transition from c-In_(2)O_(3)to rh-In_(2)O_(3)is observed with the addition of CeO_(2).The introduction of cerium into rh-In_(2)O_(3)results in a decrease in the sensor response to hydrogen,while it increases in composites based on c-In_(2)O_(3).The data on the sensor activity of the composites correlate with XPS results in which CeO_(2)causes a decrease in the concentrations of chemisorbed oxygen and oxygen vacancies in rh-In_(2)O_(3).The reverse situation is observed in composites based on c-In_(2)O_(3).Compared to In_(2)O_(3)and CeO_(2)–In_(2)O_(3)obtained by other methods,the synthesized composites demonstrate maximum response to H_(2)at low temperatures by 70–100℃,and have short response time(0.2–0.5 s),short recovery time(6–7 s),and long-term stability.A model is proposed for the dependence of sensitivity on the direction of electron transfer between In_(2)O_(3)and CeO_(2).

关键词： Cerium oxide Indium oxide Nanocomposite Hydrothermal method Cubic phase Rhombohedral phase Sensor response Conductivity Hydrogen Response/recovery time

Magnesium stress corrosion cracking

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中国有色金属学会会刊：英文版 2007年第A1期17卷 150-155页

作者： N. Winzer A. Atrens W. Dietze G. Song K. U. Kainer materials Engineering The University of Queensland Brisbane Australia swiss federal laboratories for materials science and technology EMPA Dept 136 lSrberlandstrasse 129 CH-8600 Dubendorf Switzerland GKSS-Forschungszentrum Geesthacht GmbH Germany

The significant positive green environment influence of magnesium alloy usage in transport could be compromised by catastrophic fast fracture caused by stress corrosion cracking(SCC). Transgranular stress corrosion cracking(TGSCC) of AZ91 was evaluated using the linearly increasing stress test(LIST) and the constant extension rate test(CERT). The TGSCC threshold stress was 55-75 MPa in distilled water and in 5 g/L NaCl. The TGSCC velocity was 7×10-10-5×10-9 m/s. A delayed hydride-cracking(DHC) model for TGSCC was implemented using a finite element script in MATLAB and the model predictions were compared with experiment. A key outcome is that,during steady state TGSCC propagation,a high dynamic hydrogen concentration is expected to build up behind the crack tip. A number of recommendations are given for preventing SCC of Mg alloys in service. One of the most important recommendations might be that the total stress in service(i.e. the stress from the service loading + the fabrication stress + the residual stress) should be below a threshold level,which,in the absence of other data,could be(conservatively) estimated to be about 50% of the tensile yield strength.

关键词：压力抗腐蚀强度氢化合物合金