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Temperature-Insensitive Fibre-Optic Acceleration Sensor Based on Intensity-Referenced Fibre Bragg Gratings

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Chinese Physics Letters 2008年第10期25卷 3593-3596页

作者：孙利群董博王勇新 evan LALLY 王安波 tate Key Laboratory of Precision Measurement Technoiogy and Instrument Tsinghua University Beijing 100084 Center for Photonics Technology Bradley Department of Electrical and Computer Engineering Virginia Polytechnic Institute and State University Blacksburg Virginia 24061-0111 USA

A temperature-insensitive acceleration sensor using two fibre Bragg gratings （FBGs）, based on reflection spectrum intensity modulation and optical power detection, is proposed and demonstrated. A cantilever beam is used to generate acceleration-induced axial strain along two sensing gratings, which are glued on the two opposite surfaces of the beam. Because the two gratings operate within the linear spectral range of a light source, formed by a thermally-tunable extrinsic Fabry-Perot optical filter, the intensity difference of the two reflections from the gratings is proportional to the acceleration applied. This eliminates the need for sophisticated wavelength interrogation of the gratings, and it also endows the sensor with immunity to temperature variation. Compared with a commercial micromachined accelerometer, the sensor is proven to be capable of accurately detecting acceleration.

关键词： the power-law exponents precipitation durative abrupt precipitation change

An index for deformation controllability of small-volume materials

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Science China(Technological Sciences) 2014年第4期57卷 663-670页

作者： WANG Zhangjie SHAN ZhiWei LI ju SUN jun MA evan Center for Advancing Materials Performance from the Nanoscale CAMP-Nano) & Hysitron Applied Research Center in China (HARCC) State Key Laboratory for Mechanical Behavior of Materials Xi'an Jiaotong University Department of Nuclear Science and Engineering and Department of Materials Science and Engineering Massachusetts Institute of Technology Department of Materials Science and Engineering Johns Hopkins University

Mechanical tests on small-volume materials show that in addition to the usual attributes of strength and ductility, the controlla- bility of deformation would be crucial for the purpose of precise plastic shaping. In our present work, a ＂mechanical controlla- bility index＂（MCI） has been proposed to assess the controllability of mechanical deformation quantitatively. The index allows quantitative evaluation of the relative fraction of the controllable plastic strain out of the total strain. MCI=0 means completely uncontrollable plastic deformation, MCI=∞ means perfectly controllable plastic shaping. The application of the index is demonstrated here by comparing two example cases： 0.273 to 0.429 for single crystal A1 nanopillars that exhibit obvious strain bursts, versus 3.17 to 4.2 for polycrystalline A1 nanopillars of similar size for which the stress-strain curve is smoother.

关键词： mechanical controllability index plastic deformation strain bursts nanomechanics

Mitochondria as a therapeutic:a potential new frontier in driving the shift from tissue repair to regeneration

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Regenerative Biomaterials 2023年第1期10卷 1332-1355页

作者： evan N.Main Thaiz M.Cruz Gary L.Bowlin Department of Biomedical Engineering University of Memphis330 Engineering Technology BuildingMemphisTN 38152USA

Fibrosis,or scar tissue development,is associated with numerous pathologies and is often considered a worst-case scenario in terms of wound healing or the implantation of a *** that remains is a disorganized,densely packed and poorly vascularized bundle of connective tissue,which was once functional *** creates a significant obstacle to the restoration of tissue function or integration with any ***,it is of paramount importance in tissue engineering and regenerative medicine to emphasize regeneration,the successful recovery of native tissue function,as opposed to repair,the replacement of the native tissue(often with scar tissue).A technique dubbed‘mitochondrial transplantation’is a burgeoning field of research that shows promise in in vitro,in vivo and various clinical applications in preventing cell death,reducing inflammation,restoring cell metabolism and proper oxidative balance,among other reported ***,there is currently a lack of research regarding the potential for mitochondrial therapies within tissue engineering and regenerative ***,this review explores these promising findings and outlines the potential for mitochondrial transplantation-based therapies as a new frontier of scientific research with respect to driving regeneration in wound healing and host-biomaterial interactions,the current successes of mitochondrial transplantation that warrant this potential and the critical questions and remaining obstacles that remain in the field.

关键词： mitochondrial transplantation host-biomaterial integration biomaterials wound healing fibrosis

In-situ surface transformation of magnesium to protect against oxidation at elevated temperatures

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journal of Materials Science & Technology 2020年第9期44卷 48-53页

作者： Yuecun Wang Meng Li Yueqing Yang Xin’ai Zhao evan Ma Zhiwei Shan Center for Advancing Materials Performance from the Nanoscale(CAMP-Nano)&Hysitron Applied Research Center in China(HARCC) State Key Laboratory for Mechanical Behavior of MaterialsXi’an Jiaotong UniversityXi’an710049China Department of Materials Science and Engineering Johns Hopkins UniversityBaltimore21218MDUSA

The native oxide thin scale on magnesium(Mg)surface appears continuous and crack-free,but cannot protect the Mg matrix from further oxidation,especially at elevated *** thermal oxidation process is witnessed in its entirety using a home-made in-situ heating device inside an environmental electron transmission *** proposed,and verified with real-time experimental evidence,that transforming the native oxide scale into a thin continuous surface layer with high vacancy formation energy(low vacancy concentration),for example MgCO3,can effectively protect Mg from high-temperature oxidation and raise the threshold oxidation temperature by at least two hundred degrees.

关键词： Magnesium Thermal oxidation In-situ E-TEM Carbonation Oxidation inhibition

Adoption of technologies that enhance soil carbon sequestration in East Africa. What influence farmers' decision?

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International Soil and Water Conservation Research 2020年第1期8卷 90-101页

作者： Stanley Karanja Ng'ang'a Dorcas Anyango jalang'o evan Hartunian Girvetz International Centre for Tropical Agriculture(CIAT) National Agricultural Research Laboratories-KawandaP.O.Box 6247KampalaUganda International Centre for Tropical Agriculture(CIAT) P.O.Box 823-00621NairobiKenya

The last two decades have seen a rise of interest in the adoption and diffusion of agricultural technologies aimed at improving the sustainability of agricultural lands among smallholder farmers in developing *** papers set out to understand factors that influence the adoption of technologies that enhance soil carbon sequestration among smallholder farmers,using secondary data recorded in the World Overview of Conservation Approaches and Technologies(WOCAT)database from 45 to 50 smallholders'farmers in selected places in Kenya and Ethiopia respectively.A Probit model was used to analyse whether socio-economic,institutional,off-farm income,technical know-how,farmers'percep-tions,and land use characteristics influences the adoption of technologies that enhance soil carbon *** results show that smallholder farmers that positively perceived net benefits of the soil carbon enhancing technologies were more likely to adopt such technologies that enhance soil carbon sequestration in both *** to off-farm income and land ownership with title deeds were also found to be positively associated with ***-farm income positively influences adoption among farmer with a moderate income(100-500US$per year)but not the rich(>500US$)*** to high level of skills and technical know-how required for implementing and maintaining a technology on the farm had a negative influence on *** shows that interventions,aimed at addressing specific factors such as inadequate skills and knowledge,change in perception among farmers,and off-farm income are likely to have the greatest impact in decisions relating to the adoption of the soil carbon enhancing practices among farmers in East Africa.

关键词： Factors Influencing The adoption Soil carbon Sequestration East Africa

Application of the neuromuscular fatigue threshold treadmill test to muscles of the quadriceps and hamstrings

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journal of Sport and Health Science 2020年第6期9卷 628-633页

作者： Clayton L.Camic Attila j.Kovacs Trisha A.VanDusseldorp Ethan C.Hill evan A.Enquist Human Performance Laboratory Exercise and Sport ScienceUniversity of Wisconsin-La CrosseLa CrosseWisconsin 54601USA Department of Exercise Science and Sport Management Kennesaw State UniversityKennesawGeorgia 30144USA Department of Nutrition and Health Sciences University of Nebraska-LincolnLincolnNebraska 68583USA Department of Kinesiology University of AlabamaTuscaloosaAlabama 35487USA

Purpose:The purposes of the present study were:(1)to determine whether the physical working capacity at the fatigue threshold(PWCFT)model that has been used for estimating the onset of neuromuscular fatigue in the vastus lateralis(VL)during incremental treadmill running could also be applied to the vastus medialis(VM),biceps femoris(BF),and semitendinosus(ST)muscles;and(2)if applicable,to compare the running velocities associated with the PWCFT among these ***:Eleven subjects(age 21.7±1.8 years)performed an incremental treadmill test to exhaustion with electromyographic signals recorded from the VL,VM,BF,and ***:The results indicated there were no significant(p>0.05)mean differences in the running velocities associated with the PWCFT for the VL(14.4±2.0 km/h),VM(14.3±1.9 km/h),BF(13.8±1.8 km/h),and ST(14.7±2.3 km/h).In addition,there were significant inter-correlations(r=0.68-0.88)among running velocities associated with the PWCFT of each *** results also indicated that 9 of the 11 subjects exhibited identical PWCFT values for at least 3 of the 4 muscles,but there were no uniform patterns for any intra-individual ***:The findings of the present study suggested that the PWCFT test is a viable method to identify neuromuscular fatigue in the quadriceps and hamstrings during incremental treadmill exercise and results in consistent PWCFT values among these muscles.

关键词： EMG amplitude Muscle activation PWCFT

Weave geometry generation avoiding interferences for mesoscale RVEs

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journal of Materials Science & Technology 2019年第12期35卷 2869-2882页

作者： Daniel Höwer Shengkai Yu Trenton M.Ricks Brett A.Bednarcyk evan j.Pineda Bertram Stier Stefanie Reese jaan-Willem Simon Institute of Applied Mechanics RWTH Aachen University52074 AachenGermany NASA Glenn Research Center ClevelandOH 44135USA Collier Research and Development Corporation Newport NewsVA 23606USA

An algorithm which allows the generation of representative volume elements(RVEs) for complex woven and warp-interlaced fiber-reinforced composite topologies while avoiding unphysical tow intersections is presented. This is achieved by extending an existing RVE generation strategy in two significant ways:(1) the local cross section shape of the tow is adjusted depending on the local tow curvature in a way that preserves the cross sectional area of the tow, and(2) the elementary crimp interval is separated into a planar and a transition region. The modifications facilitate the generation of a wide range of elaborate textile topologies without tow intersections, which are present without the proposed modifications unless complex tow to tow contact models are introduced. The mechanical properties of plain weaves were predicted based on the topology generated with the proposed algorithm as well as based on RVEs which were constructed based on actual micrographs, i.e. a "digital twin" of the actual microstructure. A comparison of the predicted mechanical properties based on finite element and Multiscale Generalized Method of Cells techniques shows close agreement. However, some differences exist with respect to experimentally determined material parameters due to the finite dimensions of the specimens. Lastly,mechanical properties of multilayered weaves are predicted with the finite element method. The considered material systems are carbon fiber in epoxy matrix as well as C/C-SiC. However, the procedure is applicable to a wide range of material systems.

关键词： RVE generation Multiscale analysis Composites

The effect of surface electronic structures of Au/TiO_2 on sonophotochemical reactions

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Chinese Chemical Letters 2018年第6期29卷 783-786页

作者： Kun Qian evan Wenbo Zhao Shuai He Wei David Wei Department of Chemistry and Center for Catalysis University of Florida Department of Chemical Physics University of Science and Technology of China

Sonophotocatalysis combines ultrasonic and light irradiations to drastically boost the chemical reaction rate and has attracted many interests for its potential applications in the environmental remediation and protection. However, it still remains unclear whether the light irradiation could couple with the ultrasound to prompt the sonophotocatalytic process. Here, we selectively excited the TiO2 and Au to manipulate the electronic structures of Au/TiO2 and studied their influence in sonophotocatalytic water（H2 O） reduction. Surprisingly, no significant increase of the hydrogen（H2） production rate was observed under either the UV light irradiation or the visible light irradiation, suggesting that the change in electronic structures of Au/TiO2 does not prompt the generation of free radicals under sonication and the reaction is dominated by the recovery of active sites through ultrasound. Our findings established an indepth understanding of the origin of the enhanced catalytic activity in sonophotocatalysis.

关键词： Sonophotocatalysis Localized surface plasmon resonance Electronic structure Water reduction Au/TiO2

Safety and Immunogenicity of SARS-CoV-2 mRNA-1273 Vaccine in Older Adults

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四川生理科学杂志 2020年第4期42卷 468-468页

作者： evan j Anderson From the Center for Childhood Infections and Vaccines of Children’s Healthcare of Atlanta and the Department of Pediatrics Emory University School of Medicine (E.J.A. V.V.E. K.F. M.S.S. C.A.R.) and Emory Vaccine Center Yerkes National Primate Research Center Emory University (M.S.S.) Atlanta and Hope Clinic Department of Medicine Emory University School of Medicine Decatur (E.J.A. N.G.R. V.K.P.) — both in Georgia the Vaccine Research Center (A.T.W. A.B.M. B.F. B.C.L. N.A.D.-R. S.O. S.D.S. K.S.C. P.A.S. M.P. J.E.L. B.S.G.) and the Division of Microbiology and Infectious Diseases (P.C.R. M. Makhene W.B. C.J.L. J.H.B.) National Institute of Allergy and Infectious Diseases National Institutes of Health Bethesda the University of Maryland School of Medicine Baltimore (K.M.N.) and the Emmes Company Rockville (M. Makowski J.A. K.C.) — all in Maryland Kaiser Permanente Washington Health Research Institute Seattle (L.A.J.) the Department of Pediatrics (j.D.C. M.R.D. L.J.S. A.J.P.) the Vanderbilt Institute for Infection Immunology and Inflammation (J.D.C. M.R.D. A.J.P.) and the Departments of Pathology Microbiology and Immunology (M.R.D.) Vanderbilt University Medical Center Nashville Moderna Cambridge MA (H.B. B.L.) and the Departments of Epidemiology and Microbiology and Immunology University of North Carolina at Chapel Hill Chapel Hill (D.R.M. R.B.).

Background:Testing of vaccine candidates to prevent infection with severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)in an older population is important,since increased incidences of illness and death from co... 详细信息

关键词： vaccine acute respiratory