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Broad-band spatial light modulation with dual epsilon-near-zero modes

Opto-Electronic Advances 2022年第6期5卷 63-73页

作者： Long Wen Xianghong Nan Jiaxiang Li david r.s.cumming Xin Hu Qin Chen Institute of Nanophotonics Jinan UniversityGuangzhou 511443China Hangzhou Dianzi University Hangzhou 310018China James Watt school of Engineering University of GlasgowGlasgow G128QQUK.

Epsilon-near-zero(ENZ)modes have attracted extensive interests due to its ultrasmall mode volume resulting in ex-tremely strong light-matter interaction(LMI)for active optoelectronic devices.The ENZ modes can be electrically toggled between on and off states with a classic metal-insulator-semiconductor(MIs)configuration and therefore allow access to electro-absorption(E-A)modulation.relying on the quantum confinement of charge-carriers in the doped semiconductor,the fundamental limitation of achieving high modulation efficiency with MIs junction is that only a nanometer-thin ENZ confinement layer can contribute to the strength of E-A.Further,for the ENZ based spatial light modulation,the require-ment of resonant coupling inevitably leads to small absolute modulation depth and limited spectral bandwidth as restric-ted by the properties of the plasmonic or high-Q resonance systems.In this paper,we proposed and demonstrated a dual-ENZ mode scheme for spatial light modulation with a TCOs/dielectric/silicon nanotrench configuration for the first time.such a sIs junction can build up two distinct ENZ layers arising from the induced charge-carriers of opposite polar-ities adjacent to both faces of the dielectric layer.The non-resonant and low-loss deep nanotrench framework allows the free space light to be modulated efficiently via interaction of dual ENZ modes in an elongated manner.Our theoretical and experimental studies reveal that the dual ENZ mode scheme in the sIs configuration leverages the large modulation depth,extended spectral bandwidth together with high speed switching,thus holding great promise for achieving electric-ally addressed spatial light modulation in near-to mid-infrared regions.

关键词： epsilon-near-zero modulation TCOs electro-optic light harvesting

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On-chip ultrasensitive and rapid hydrogen sensing based on plasmon-induced hot electron-molecule interaction

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Light(science & Applications) 2023年第4期12卷 625-635页

作者： Long Wen Zhiwei sun Qilin Zheng Xianghong Nan Zaizhu Lou Zhong Liu david r.s.cumming Baojun Li Qin Chen Guangdong Provincial Key Laboratory of Nanophotonic Manipulation Institute of NanophotonicsJinan University511443 GuangzhouChina College of Life science and Technology Jinan University510632 GuangzhouChina school of Engineering University of GlasgowGlasgow G128QQUK

Hydrogen energy is a zero-carbon replacement for fossil fuels.However,hydrogen is highly flammable and explosive hence timely sensitive leak detection is crucial.Existing optical sensing techniques rely on complex instruments,while electrical sensing techniques usually operate at high temperatures and biasing condition.In this paper an on-chip plasmonic-catalytic hydrogen sensing concept with a concentration detection limit down to 1 ppm is presented that is based on a metal-insulator-semiconductor(MIs)nanojunction operating at room temperature and zero bias.The sensing signal of the device was enhanced by three orders of magnitude at a one-order of magnitude higher response speed compared to alternative non-plasmonic devices.The excellent performance is attributed to the hydrogen induced interfacial dipole charge layer and the associated plasmonic hot electron modulated photoelectric response.Excellent agreements were achieved between experiment and theoretical calculations based on a quantum tunneling model.such an on-chip combination of plasmonic optics,photoelectric detection and photocatalysis offers promising strategies for next-generation optical gas sensors that require high sensitivity,low time delay,low cost,high portability and flexibility.

关键词： hydrogen interaction hence

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A monolithic single-chip point-of-care platform for metabolomic prostate cancer detection

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Microsystems & Nanoengineering 2021年第2期7卷 81-95页

作者： Valerio F.Annese samadhan B.Patil Chunxiao Hu Christos Giagkoulovits Mohammed A.Al-rawhani James Grant Martin Macleod david J.Clayton Liam M.Heaney ronan Daly Claudio Accarino Yash D.shah Boon C.Cheah James Beeley Thomas r.Jeffry Evans robert Jones Michael P.Barrett david r.s.cumming Electronics and Nanoscale Engineering James Watt School of EngineeringUniversity of GlasgowGlasgowG128QQUK Beatson West of scotland Cancer Centre GlasgowG120YNUK school of science and Technology Nottingham Trent UniversityNottinghamNG118NFUK school of sport Exercise&Health SciencesLoughborough UniversityLoughboroughLE113TUUK Glasgow Polyomics College of MedicalVeterinary and Life SciencesUniversity of GlasgowGlasgowG611BDUK Institute of Cancer sciences Beatson West of Scotland Cancer CentreUniversity of GlasgowGlasgowG120YNUK Institute of Infection Immunity and InflammationUniversity of GlasgowGlasgowG128TAUK

There is a global unmet need for rapid and cost-effective prognostic and diagnostic tools that can be used at the bedside or in the doctor’s office to reduce the impact of serious disease.Many cancers are diagnosed late,leading to costly treatment and reduced life expectancy.With prostate cancer,the absence of a reliable test has inhibited the adoption of screening programs.We report a microelectronic point-of-care metabolite biomarker measurement platform and use it for prostate cancer detection.The platform,using an array of photodetectors configured to operate with targeted,multiplexed,colorimetric assays confined in monolithically integrated passive microfluidic channels,completes a combined assay of 4 metabolites in a drop of human plasma in under 2 min.A preliminary clinical study using L-amino acids,glutamate,choline,and sarcosine was used to train a cross-validated random forest algorithm.The system demonstrated sensitivity to prostate cancer of 94%with a specificity of 70%and an area under the curve of 0.78.The technology can implement many similar assay panels and hence has the potential to revolutionize low-cost,rapid,point-of-care testing.

关键词： inhibited specificity hence

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single-atom Pt on carbon nanotubes for selective electrocatalysis

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Carbon Energy 2024年第1期6卷 63-71页

作者： samuel s.Hardisty Xiaoqian Lin Anthony r.J.Kucernak david Zitoun Department of Chemistry Bar Ilan Institute of Nanotechnology and Advanced Materials(BINA)Bar Ilan UniversityRamat GanIsrael Department of Chemistry Molecular Science Research HubImperial College LondonLondonUK

Utilizing supported single atoms as catalysts presents an opportunity to reduce the usage of critical raw materials such as platinum,which are essential for electrochemical reactions such as hydrogen oxidation reaction(HOr).Herein,we describe the synthesis of a Pt single electrocatalyst inside single-walled carbon nanotubes(sWCNTs)via a redox reaction.Characterizations via electron microscopy,X-ray photoelectron microscopy,and X-ray absorption spectroscopy show the single-atom nature of the Pt.The electrochemical behavior of the sample to hydrogen and oxygen was investigated using the advanced floating electrode technique,which minimizes mass transport limitations and gives a thorough insight into the activity of the electrocatalyst.The single-atom samples showed higher HOr activity than state-of-the-art 30%Pt/C while almost no oxygen reduction reaction activity in the proton exchange membrane fuel cell operating range.The selective activity toward HOr arose as the main fingerprint of the catalyst confinement in the sWCNTs.

关键词： confinement electrocatalysis hydrogen platinum single atom catalysts

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role of climatic variability in shaping intraspecific variation of thermal tolerance in Mediterranean water beetles

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Insect science 2024年第1期31卷 285-298页

作者： susana Pallarés david Garoffolo Belén rodríguez david sánchez-Fernández Department of Zoology University of SevilleSevilleSpain Faculty of Biology Department of Ecology and HydrologyUniversity of MurciaCampus EspinardoMurciaSpain

The climatic variability hypothesis(CVH)predicts that organisms in more thermally variable environments have wider thermal breadths and higher thermal plasticity than those from more stable environments.However,due to evolutionary trade-offs,taxa with greater absolute thermal limits may have little plasticity of such limits(trade-off hypothesis).The CVH assumes that climatic variability is the ultimate driver of thermal tolerance variation across latitudinal and altitudinal gradients,but average temperature also varies along such gradients.We explored intraspecific variation of thermal tolerance in three typical Mediterranean saline water beetles(families Hydrophilidae and Dytiscidae).For each species,we compared two populations where the species coexist,with similar annual mean temperature but contrasting thermal variability(continental vs.coastal population).We estimated thermal limits of adults from each population,previously acclimated at 17,20,or 25℃.We found species-specific patterns but overall,our results agree with the CVH regarding thermal ranges,which were wider in the continental(more variable)population.In the two hydrophilid species,this came at the cost of losing plasticity of the upper thermal limit in this population,supporting the trade-off hypothesis,but not in the dytiscid one.Our results support the role of local adaptation to thermal variability and trade-offs between basal tolerance and physiological plasticity in shaping thermal tolerance in aquatic ectotherms,but also suggest that intraspecific variation of thermal tolerance does not fit a general pattern among aquatic insects.Overlooking such intraspecific variation could lead to inaccurate predictions of the vulnerability of aquatic insects to global warming.

关键词： acclimation capacity aquatic insects climate change heat coma temperature supercooling point thermal plasticity

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Astrophysical s-factor and reaction rate for 15N(p,γ)16O within the modified potential cluster model

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Chinese Physics C 2024年第4期48卷 130-145页

作者： s.B.Dubovichenko A.s.Tkachenko r.Ya.Kezerashvili N.A.Burkova B.M.Yeleusheva Fesenkov Astrophysical Institute 050020 AlmatyKazakhstan New York City College of Technology City University of New YorkBrooklyn11201 New YorkUSA Graduate school and University Center City University of New York10016 New YorkUSA al-Farabi Kazakh National University 050040 AlmatyKazakhstan

We study radiative p^(15)N capture on the ground state of ^(16)O at stellar energies within the framework of a modified potential cluster model(MPCM)with forbidden states,including low-lying resonances.The investigation of the ^(15)N(p,γ0)^(16)O reaction includes the consideration of ^(3)s_(1) resonances due to E1 transitions and the contribution of the ^(3)P_(1) scattering wave in the p+^(15)N channel due to the ^(3)P_(1)→^(3)P_(0)M1 transition.We calculated the astrophysical low-energy s-factor,and the extrapolated s(0)turned out to be within 34.7−40.4 keV·b.The important role of the asymptotic constant(AC)for the ^(15)N(p,γ0)16O process with interfering ^(3)s_(1)(312)and ^(3)s_(1)(962)resonances is elucidated.A comparison of our calculation for the s-factor with existing experimental and theoretical data is addressed,and a reasonable agreement is found.The reaction rate is calculated and compared with the existing rates.It has negligible dependence on the variation of AC but shows a strong impact of the interference of ^(3)s_(1)(312)and ^(3)s_(1)(962)resonances in reference to the CNO Gamow windows,especially at low temperatures.We estimate the contribution of cascade transitions to the reaction rate based on the exclusive experimental data from Phys.rev.C.85,065810(2012).The reaction rate enhancement due to the cascade transitions is observed from T_(9)>0.3 and reaches the maximum factor~1.3 at T_(9)=1.3.We present the Gamow energy window and a comparison of rates for radiative proton capture reactions ^(12)N(p,γ)^(13)O,^(13)N(p,γ)^(14)O,^(14)N(p,γ)^(15)O,and ^(15)N(p,γ)^(16)O obtained in the framework of the MPCM and provide the temperature windows,prevalence,and significance of each process.

关键词： low and astrophysical energies p^(15)N system thermonuclear reaction rate potential cluster model CNO-cycle

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soil security and global food security

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Frontiers of Agricultural science and Engineering 2024年第2期11卷 297-302页

作者： david r.MONTGOMErY Department of Earth and space sciences University of Washington town

Over the course of the postglacial period has managed to add degrade a substantial portion of the world's potential agricultural land. The soil loss and degradation that has repeatedly impacted regional societies around the world resulted from agricultural practices that increased the physical loss of soil(erosion), reduced soil organic matter, changed p H(acidification) or salinity,and disrupted or altered communities of soil life. In the coming century, as continued soil degradation threatens global food security while the global population keeps rising it is imperative that farmers develop and adopt soilhealth building(regenerative) practices to solve a problem that has plagued societies throughout history. Growing evidence suggests that agricultural systems that combine cover crops, reduced tillage, and diverse crop rotations can reduce erosion, enhance soil health and rebuild soil organic matter to cultivate beneficial soil life and harvest both economic and environmental benefits. In the coming post-oil world, global food security would benefit from a global effort to promote soil restoration to help addresses the challenge of sustainably feeding the world, increase soil-based carbon sequestration,protect on-farm biodiversity and reduce off-farm water pollution. Because soil security sets a solid foundation for global food security, agricultural policies and subsidies should be reformed to encourage farmers to adopt regenerative,soil-building practices.

关键词： Agriculture soil security food security regenerative

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FEA-based Geometrical Modification of switched reluctance Motor for radial Force reduction

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Chinese Journal of Electrical Engineering 2024年第1期10卷 124-135页

作者： rani s Jayapragash r school of Electrical Engineering Vellore Institute of TechnologyChennai 600127India

switched reluctance motors(srMs)are becoming increasingly popular in the automotive sector owing to their robust design.Moreover,srMs are preferred particularly for EV applications owing to their fault tolerance,magnet-free structure,and high power/torque density.The main concerns of srM compared to other machines include torque ripple and vibration.The primary cause of vibration is the radial force created by the srM.A geometry-based modification of the srM to reduce the radial force without significantly changing the average torque produced is proposed.The primary goal is to design a 4-phase,8/6 srM with a lower radial force.Two possible geometrical alterations are proposed:one with square windows and the other with circular holes on the rotor core.The windows are sized and positioned to avoid flux saturation.General criteria are developed for the optimal window size and placement.Finite element analysis(FEA)modelling of the srM is used to validate its performance.The FEA results are compared with the performance parameters obtained using the analytical method.Utilizes the multiphysics design tool ANsYs to obtain the natural frequencies and associated deformations through modal analysis.Compared to the conventional geometry,the radial force is significantly reduced by providing windows.

关键词： 8/6 srM radial force modal analysis FEA analysis natural frequencies srM with windows

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There is more to the knee joint than just the quadriceps:A systematic review with meta-analysis and evidence gap map of hamstring strength,flexibility,and morphology in individuals with gradual-onset knee disorders

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Journal of sport and Health science 2024年第4期13卷 521-536页

作者： Helder s.Lopes Marina C.Waiteman Liliam B.Priore Neal r.Glaviano david M.Bazett-Jones ronaldo V.Briani Fabio M.Azevedo school of science and Technology Physical Therapy DepartmentSao Paulo State University(UNESP)Presidente Prudente 19060-900Brazil Department of Kinesiology College of AgricultureHealth and Natural ResourcesUniversity of ConnecticutStorrsCT 06269USA school of Exercise and rehabilitation sciences College of Health and Human ServicesUniversity of ToledoToledoOH 43606USA

Background:Impairments in hamstring strength,flexibility,and morphology have been associated with altered knee biomechanics,pain,and function.Determining the presence of these impairments in individuals with gradual-onset knee disorders is important and may indicate targets for assessment and rehabilitation.This systematic review aimed to synthesize the literature to determine the presence of impairments in hamstring strength,flexibility,and morphology in individuals with gradual-onset knee disorders.Methods:Five databases(MEDLINE,Embase,CINAHL,sPOrTDiscus,and Web of science)were searched from inception to september 2022.Only studies comparing hamstring outcomes(e.g.,strength,flexibility,and/or morphology)between individuals with gradual-onset knee disorders and their unaffected limbs or pain-free controls were included.Meta-analyses for each knee disorder were performed.Outcome-level certainty was assessed using the Grading of recommendations Assessment,Development,and Evaluation,and evidence gap maps were created.results:seventy-nine studies across 4 different gradual-onset knee disorders(i.e.,knee osteoarthritis(OA),patellofemoral pain(PFP),chondromalacia patellae,and patellar tendinopathy)were included.Individuals with knee OA presented with reduced hamstring strength compared to pain-free controls during isometric(standard mean difference(sMD)=-0.76,95%confidence interval(95%CI):-1.32 to-0.21)and concentric contractions(sMD=-0.97,95%CI:-1.49 to-0.45).Individuals with PFP presented with reduced hamstring strength compared to painfree controls during isometric(sMD=-0.48,95%CI:-0.82 to-0.14),concentric(sMD=-1.07,95%CI:-2.08 to-0.06),and eccentric contractions(sMD=-0.59,95%CI:-0.97 to-0.21).No differences were observed in individuals with patellar tendinopathy.Individuals with PFP presented with reduced hamstring flexibility when compared to pain-free controls(sMD=-0.76,95%CI:-1.15 to-0.36).Evidence gap maps identified insufficient evidence for chondromalacia patellae and hamstring morphology across all gradual-

关键词： Chondromalacia patellae Knee flexors Knee osteoarthritis Patellar tendinopathy Patellofemoral pain

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Kinematic analysis of flexible bipedal robotic systems

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Applied Mathematics and Mechanics(English Edition) 2024年第5期45卷 795-818页

作者： r.FAZEL A.M.sHAFEI s.r.NEKOO Department of Mechanical Engineering Shahid Bahonar University of KermanKerman ***Iran Departamento de Ingenieria de sistemas y Automatica Escuela Técnica Superior de IngenieriaUniversidad de SevillaSeville 41092Spain

In spite of its intrinsic complexities,the passive gait of bipedal robots on a sloping ramp is a subject of interest for numerous researchers.What distinguishes the present research from similar works is the consideration of flexibility in the constituent links of this type of robotic systems.This is not a far-fetched assumption because in the transient(impact)phase,due to the impulsive forces which are applied to the system,the likelihood of exciting the vibration modes increases considerably.Moreover,the human leg bones that are involved in walking are supported by viscoelastic muscles and ligaments.Therefore,for achieving more exact results,it is essential to model the robot links with viscoelastic properties.To this end,the Gibbs-Appell formulation and Newton's kinematic impact law are used to derive the most general form of the system's dynamic equations in the swing and transient phases of motion.The most important issue in the passive walking motion of bipedal robots is the determination of the initial robot configuration with which the system could accomplish a periodic and stable gait solely under the effect of gravitational force.The extremely unstable nature of the system studied in this paper and the vibrations caused by the impulsive forces induced by the impact of robot feet with the inclined surface are some of the very serious challenges encountered for achieving the above-mentioned goal.To overcome such challenges,an innovative method that uses a combination of the linearized equations of motion in the swing phase and the algebraic motion equations in the transition phase is presented in this paper to obtain an eigenvalue problem.By solving this problem,the suitable initial conditions that are necessary for the passive gait of this bipedal robot on a sloping surface are determined.The effects of the characteristic parameters of elastic links including the modulus of elasticity and the Kelvin-Voigt coefficient on the walking stability of this type of robotic systems are also studied.The findings o

关键词： bipedal robot flexible link swing phase transient phase eigenvalue problem Kelvin-Voigt coefficient

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