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Targeted principle component analysis:A new motion artifact correction approach for near-infrared spectroscopy

Journal of Innovative Optical Health Sciences 2014年第2期7卷 98-105页

作者： Meryen A.Yücel Julitte Selb Robert J.C.ooper David A.Boas Athinoula A.Martinos Center for Biomedical Imaging department of Radiology Massachusetts General Hospital Haruard Medical SchoolCharlestownMAUSA department of medical physics and bioengineering university college london LondonUK

As near-infrared spectroscopy(NIRS)broadens its application area to diferent age and diseasegroups,motion artifacts in the NIRS signal due to subject movement is becoming an *** artifacts generally produce signal fiuctuations that are larger than physio-logical NIRS signals,thus it is cruciai to corect for them before obtaining an cstimate ofstimulusevoked hemodynamic responses.,There are various methods for correction such as principlecomponent analy sis(P CA),wavelet-based filt ering and spline int ***,we introduce anew approach to motion artifact correction,targeted principle component analysis(PCA),which incorporates a PCA filter only on the segments of data identified as motion *** expected that this will overcome the issues of filtering desired signals that plagues standardPCA fitering of entire data *** compared the new approach with the most efiective motionartifact correction algorithms on a set of data acquired simultaneously with a collodion-fixedprobe(low motion artifact content)and a standard Velcro probe(high motion artifact content).Our results show that tPCA gives statistically better results in recovering hemodynamic responsefunction(HRF)as compared to wavelet-based fltering and spline interpolation for the *** resulis in a significant reduction in mean-squauared'error(MSE)and significant en-hancement in Pearson's correlation coeficient to the true HRF,The collodion-fixed fiber probewith no motion correction performed better than the Velcro probe corrected for motion artifactsin terms of MSE and Pearson's correlation ***,if the experimental study permits,the use of a collodion-fixed fiber probe may be desirable.I the use of a collodion-fixed probe is notfeasible,then we suggest the use of tP CA in the processing of motion artifact contaminated data.

关键词： Wavelet spline collodion-fixed fiber.

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Light tuning CO/H_(2)composition on Ag:Unraveling CO_(2)mass transfer and electron-phonon coupling in plasmon-enhanced electrocatalysis

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Nano Research 2025年第1期18卷 173-185页

作者： Rui Lin Dong Fan Luca MBerger Thomas Possmayer Yu Zhou Jiexin Zhu Xingbao Chen Wen Luo Lars Allmendinger Andreas Tittl Leonardo de Souza Menezes Guillaume Maurin Shihe Yang and Stefan AMaier Nanoinstitute Munich Faculty of PhysicsLudwig-Maximilians-Universität München80539 MunichGermany Institut Charles Gerhardt Montpellier UMR 5253 CNRS ENSCM UniversitéMontpellierPlace E.Bataillon34090 MontpellierFrance Guangdong Provincial Key Lab of Nano-Micro Material Research School of Advanced MaterialsPeking University Shenzhen Graduate SchoolShenzhen 518055China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China Faculty of Chemistry and Pharmacy Ludwig-Maximilians-Universität München81377 MunichGermany Departamento de Física Universidade Federal de Pernambuco50670-901 Recife-PEBrazil School of physics and Astronomy Monash University Clayton CampusMelbourneVictoria 3800Australia department of physics Imperial College LondonSW72AZ LondonUK

Plasmon-enhanced electrocatalysis(PEEC)is an emerging approach to mitigate CO_(2)*** mechanisms behind CO_(2)adsorption and reduction at the catalyst-electrolyte interface in PEEC still need to be further ***,we employ a well-defined Ag nanostructure to elucidate these pivotal *** shining light with wavelengths of 625,525,405 nm on Ag,an adjustable CO/H_(2)ratio from 35 to 1 can be *** reaction pathway changing under plasmonic excitation does not originate from the lowered CO_(2)mass transfer in the vicinity of Ag,as the electrochemical quartz crystal microbalance results unravel that a slightly elevated temperature in bulk electrolyte caused by light irradiation cannot weaken the CO_(2)adsorption at the Ag catalyst-electrolyte *** calculations reveal that optical excitation towards shorter wavelengths leads to a progressive lowered energy barrier for H_(2)formation together with an enhanced energy barrier for^(*)COOH *** thermodynamically suppressed,CO_(2)reduction can still be improved kinetically by optimizing the excitation wavelength and intensity,being accompanied with the enhanced *** absorption spectroscopy results further correlate the higher photocurrent with a prolonged electron-phonon coupling time,verifying that the improvement of CO_(2)reduction kinetics in PEEC can be realized by hot electron harnessing.

关键词： plasmonic catalysis photoelectrochemical CO_(2)reduction CO/H_(2)ratio hot electron generation electronphonon coupling thermal effect

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Woven fabric triboelectric nanogenerators for human-computer interaction and physical health monitoring

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Nano Research 2024年第6期17卷 5540-5548页

作者： Yu Miao Mengjuan Zhou Jia Yi Yanyan Wang Guangjin Tian Hongxia Zhang Wenlong Huang Wenhao Wang Ronghui Wu Liyun Ma college of Textile and Clothing Xinjiang UniversityUrumqi 830046China college of Textiles Donghua UniversityShanghai 201620China college of physics Xiamen UniversityXiamen 201620China department of bioengineering Imperial College LondonLondon SW72AZUK

Triboelectric nanogenerator(TENG)converts mechanical energy into valuable electrical energy,offering a solution for future energy *** an indispensable part of TENG,textile TENG(T-TENG)has incredible advantages in harvesting biomechanical energy and physiological signal ***,the application of T-TENG is restricted,partly because the fabric structure parameter and structure on T-TENG performance have not been fully *** study comprehensively investigates the effect of weaving structure on fabric TENGs(F-TENGs)for direct-weaving yarn TENGs and post-coating fabric *** direct-weaving F-TENGs,a single-yarn TENG(Y-TENG)with a core-sheath structure is fabricated using conductive yarn as the core layer yarn and polytetrafluoroethylene(PTFE)filaments as the sheath *** fabrics with five different sets of parameters were designed and *** post-coating F-TENGs,fabrics with weaving structures of plain,twill,satin,and reinforced twill were fabricated and coated with conductive silver ***,the twill F-TENGs have the best electrical outputs,followed by the satin F-TENGs and plain weave ***,the increase of the Y-TENG gap spacing was demonstrated to improve the electrical output ***,T-TENGs are demonstrated for human-computer interaction and self-powered real-time *** systematic work provides guidance for the future T-TENG’s design.

关键词： single-yarn triboelectric nanogenerators woven fabric triboelectric nanogenerators fabric weaving structures and parameters human-computer interaction physical health monitoring

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The Key Role of the Blood Supply to Bone

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Bone Research 2013年第3期1卷 203-215页

作者： Massimo Marenzana Timothy R.Arnett department of bioengineering Imperial College London and Kennedy Institute of Rheumatology University of OxfordUK department of Cell and Developmental Biology University College LondonUK

The importance of the vascular supply for bone is well-known to orthopaedists but is still rather overlooked within the wider field of skeletal research. Blood supplies oxygen, nutrients and regulatory factors to tissues, as well as removing metabolic waste products such as carbon dioxide and acid. Bone receives up to about 10% of cardiac output, and this blood supply permits a much higher degree of cellularity, remodelling and repair than is possible in cartilage, which is avascular. The blood supply to bone is delivered to the endosteal cavity by nutrient arteries, then flows through marrow sinusoids before exiting via numerous small vessels that ramify through the cortex. The marrow cavity affords a range of vascular niches that are thought to regulate the growth and differentiation of hematopoietic and stromal cells, in part via gradients of oxygen tension. The quality of vascular supply to bone tends to decline with age and may be compromised in common pathological settings, including diabetes, anaemias, chronic airway diseases and immobility, as well as by tumours. Reductions in vascular supply are associated with bone loss. This may be due in part to the direct effects of hypoxia, which blocks osteoblast function and bone formation but causes reciprocal increases in osteoclastogenesis and bone resorption. Common regulatory factors such as parathyroid hormone or nitrates, both of which are potent vasodilators, might exert their osteogenic effects on bone via the vasculature. These observations suggest that the bone vasculature will be a fruitful area for future research.

关键词： vasculature skeleton oxygen hypoxia osteoblast osteoclast

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Constrain the Jerk Parameters with DESI 2024 Data

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Research in Astronomy and Astrophysics 2024年第12期24卷 177-184页

作者： Jia-Wei Wu Kun-Yuan Hong School of physics and Astronomy Sun Yat-sen University department of physics and Astronomy University College London

The deceleration coefficient q and the jerk coefficient j obtained by the Taylor expansion of the scale factor a（t）play an important role in the study of *** current value of these coefficients for a cosmological model reflects the transition time between the phases dominated by dark energy and matter and can be used to determine if and how much the universe is ***,these coefficient values offer a way of constraining a particular cosmology *** based on this scenario was completed by Orlando Luongo and Marco ***,some approaches in this method should be tested prudently because some conditions such as ■may not be *** this study,we used the MAPAge model to reconstruct the jerk parameters （q0and j0） with DESI 2024 *** the MAPAge model ensures particular physical circumstances are satisfied in the approach of determining the jerk *** to the previous method,which used the Taylor expansion series q0,j0,and s0as model-independent parameters,we obtained more physical and slightly different results for the jerk *** results suggest that the DESI 2024 BAO data set favours different jerk parameters compared to the jerk parameters in the standardΛCDM model.

关键词： (cosmology:) cosmological parameters (cosmology:) dark energy (cosmology:) large-scale structure of universe

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Tuning structural,electrical,dielectric and magnetic properties of Mg-Cu-Co ferrites via dysprosium(Dy^(3+))doping

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Journal of Rare Earths 2024年第1期42卷 137-146,I0005页

作者： Maria Akhtar M.S.Hasan Nasir Amin N.A.Morley Muhammad Imran Arshad department of physics Government College UniversityFaisalabad38000Pakistan department of physics The University of Lahore53700Pakistan department of Materials Science and Engineering The University of SheffieldS13JDUK department of physics&Astronomy University College LondonUK

In current research work,Dy3+substituted Mg0.5Cu0.25Co0.25Fe2-xDyxO4(0.0≤x≤0.04 with the step interval of 0.01)soft ferrites were synthesized by the sol-gel auto combustion *** prepared samples were characterized by the techniques using X-ray diffraction(XRD),scanning electron microscopy(SEM),energy dispersive X-ray spectroscopy(EDS),Fourier transform infrared(FTIR)spectroscopy,curre nt-voltage(Ⅰ-Ⅴ)measurement,LCR meter,vibrating sample magnetometer(VSM)and *** data reveal that the average crystallite size is 49.71 nm and the lattice constant is 0.83703 nm for sample x=*** non-uniform grain growth was demonstrated by micrographs and impurity-free elemental composition was observed from EDX *** DC resistivity has an increasing and decreasing trend in ferromagnetic and paramagnetic regions with an increase in ***,the high resistivity is observed with the order of 1010Ω·cm,and the activation energy is 0.944 eV for samples x=*** dielectric parameters including dielectric constant,dielectric losses,and impedance gradually decrease with the increase in frequency from 8 Hz to 8 *** minimum dielectric loss at high frequency is found for sample x=*** coercivity(Hc)and saturation magnetization(Ms)are found in the ranges of 520.82-544.02 Oe and 20.5841-21.1473 emu/g,*** observations confirm that dysprosium(x=0.03)doped MCC-soft ferrites may be applicable in transformer cores,microwave absorbance,and telecommunication devices.

关键词： Soft ferrites DC resistivity Dielectric loss Impedance Coercivity Rare earths

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Atomic-to-molecular gas conversion:Combining multi-wavelength and multi-scale data

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Science China(physics,Mechanics & Astronomy) 2024年第9期67卷 203-204页

作者： Amelie Saintonge department of physics and Astronomy University College LondonLondon WC1E 6BTUK

Our view on galaxy evolution has changed significantly over the past decade,with considerable attention now being paid to better understanding the full baryon *** includes careful characterisation of the gas flows in and out of galaxies,the connection of galaxies with their circumgalactic medium,and the impacts of feedback on the interstellar medium.

关键词： galaxies galaxy galactic

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Temperature-Dependent Photoluminescence Characteristics of InAs/GaAs Quantum Dots Directly Grown on Si Substrates

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Chinese physics Letters 2016年第4期33卷 52-55页

作者：王霆刘会赟张建军 Institute of physics Chinese Academy of Sciences department of Electronic & Electrical Engineering University College London

The first operation of an electrically pumped 1.3μm InAs/GaAs quantum-dot laser was previously reported epitaxially grown on Si （100） substrate. Here the direct epitaxial growth condition of 1.3μm InAs/OaAs quantum on a Si substrate is further investigated using atomic force microscopy, etch pit density and temperature-dependent photoluminescence （PL） measurements. The PL for Si-based InAs/GaAs quantum dots appears to be very sensitive to the initial OaAs nucleation temperature and thickness with strongest room-temperature emission at 40000 （17Onto nucleation layer thickness）, due to the lower density of defects generated under this growth condition, and stronger carrier confinement within the quantum dots.

关键词： GaAs InAs Temperature-Dependent Photoluminescence Characteristics of InAs/GaAs Quantum Dots Directly Grown on Si Substrates of Si on

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Relativistic Theoretical Calculation of O III:Radiative Transition Rates and the Bowen Mechanism in Planetary Nebulae

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Chinese physics Letters 1994年第2期11卷 69-72页

作者： TONG Xiaomin ZOU Yu LI Jiaming LIU Xiaowei Institute of physics Academia SinicaBeijing 100080 department of physics and Astronomy University College LondonUK

A full relativistic configuration interaction(RCI)calculation of transition energies and radiative transition rates involved in O III Bowen fluorescence mechanism is *** calculated ratios of transition line intensities are in good agreement with the observed *** discrepancies between the RCI calculation and prediction based on LS coupling scheme show that a delicate balance between the electron correlations and the spin-orbital interactions should be important even for the low-Z O Ⅲ ion.

关键词： Transition transition orbital

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Entanglement and discord assisted entropic uncertainty relations under decoherence

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Science China(physics,Mechanics & Astronomy) 2014年第9期57卷 1703-1711页

作者： YAO ChunMei CHEN ZhiHua MA ZhiHao SEVERINI Simone SERAFINI Alessio department of physics and Electronic Science Hunan University of Arts and Science department of physics and Astronomy University College London department of Science Zhijiang College Zhejiang University of Technology Centre for Quantum Technologies National University of Singapore department of Mathematics Shanghai JiaoTong University department of Computer Science University College London Gower Street

The uncertainty principle is a crucial aspect of quantum *** has been shown that quantum entanglement as well as more general notions of correlations,such as quantum discord,can relax or tighten the entropic uncertainty relation in the presence of an ancillary *** explored the behaviour of entropic uncertainty relations for system of two qubits—one of which subjects to several forms of independent quantum noise,in both Markovian and non-Markovian *** uncertainties and their lower bounds,identified by the entropic uncertainty relations,increase under independent local unital Markovian noisy channels,but they may decrease under non-unital *** behaviour of the uncertainties(and lower bounds)exhibit periodical oscillations due to correlation dynamics under independent non-Markovian *** addition,we compare different entropic uncertainty relations in several special cases and find that discord-tightened entropic uncertainty relations offer in general a better estimate of the uncertainties in play.

关键词： entropic uncertainty relation entanglement quantum discord decoherence Markovian and non-Markovian reservoirs

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