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Origin of tradeoff between movement velocity and attachment duration of kinesin motor on a microtubule

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Chinese physics B 2024年第2期33卷 557-566页

作者：刘玉颖张志强 Department of physics College of ScienceChina Agricultural UniversityBeijing 100083China Basic Ministry Space Engineering UniversityBeijing 101416China

Kinesin-1 motor protein is a homodimer containing two identical motor domains connected by a common long coiledcoil stalk via two flexible neck linkers. The motor can step on a microtubule with a velocity of about 1 μm·s-1and an attachment duration of about 1 s under physiological conditions. The available experimental data indicate a tradeoff between velocity and attachment duration under various experimental conditions, such as variation of the solution temperature,variation of the strain between the two motor domains, and so on. However, the underlying mechanism of the tradeoff is unknown. Here, the mechanism is explained by a theoretical study of the dynamics of the motor under various experimental conditions, reproducing quantitatively the available experimental data and providing additional predictions. How the various experimental conditions lead to different decreasing rates of attachment duration versus velocity is also explained.

关键词： motor protein velocity detachment time processivity

Luminescence properties and optical sensing behaviors of Sr_(2)GdSbO_(6):Eu^(3+) phosphors

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Journal of Rare Earths 2024年第8期42卷 1458-1469,I0002页

作者： Youfa Tai Ruirui Cui Jun Zhang Chunkai Wang Tingyu Zhao Beiqiao Zhang Chaoyong Deng Key Laboratory of Functional Composite Materials of Guizhou Province College of Big Data and Information EngineeringGuizhou UniversityGuiyang550025China college of Computer and Information engineering Guizhou University of CommerceGuiyang550014China School of electronics and Information engineering Guiyang UniversityGuiyang550005China

Novel orange-red Sr_(2)GdSbO_(6):xEu^(3+)(x=0,0.05,0.1,0.2,0.3,0.4,0.5 and 0.6) phospho rs were successfully prepared by the traditional high-temperature solid-state *** results of Rietveld refinement,energy dispersive spectroscopy(EDS) spectrum and elemental mapping demonstrate that Eu^(3+) successfully replaces the Gd^(3+) sites and distributes uniformly in the particles of *** luminescence properties of Sr_(2)GdSbO_(6):Eu_(3+)phosphors were investigated in *** emission spectra of the strongest emission peak is the ^(5)D_(0)→^(7)F_(1)(593 nm) transition,which can emit orange-red light under393 nm *** the doping concentration of Eu3+ions is x=0.2,the luminescence intensity of the phosphors reaches the *** detailed mechanism of concentration quenching is attributed to dipole-dipole *** thermal stability values of Sr_(2)GdSbO_(6):0.2Eu^(3+) phosphors are 87%,82% and114% under 393,467 and 527 nm excitations,*** causes of the abnormal thermal quenching under 527 nm excitation were *** on the abnormal thermal quenching under527 nm excitation,the optical thermometry properties of Sr_(2)GdSbO_(6):0.2Eu^(3+)phosphors were investigated by fluorescence intensity ratio(FIR) technique,and appreciable relative sensitivity was *** results suggest that Sr_(2)GdSbO_(6):0.2Eu^(3+)phosphors can be potentially applied to w-LEDs and optical thermometers.

关键词： Sr_(2)GdSbO_(6):Eu^(3+) Phosphors Luminescence properties Abnormal thermal quenching Rare earths

Highly efficient tunable photodetector with a bipolar response in van der Waals heterojunctions

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Science China(Technological Sciences) 2024年第2期67卷 639-646页

作者： SHI ChaoFan ZHANG Shi XIAO KeNing ZHANG LiBo HAN Li ZHU YuLin TANG WeiWei LIU ChangLong LI GuanHai CHEN XiaoShuang college of physics and optoelectronic engineering Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of Sciences Hangzhou310024China State Key Laboratory of Infrared physics Shanghai Institute of Technical PhysicsChinese Academy of SciencesShanghai 200083China

The heterojunction integration of two-dimensional(2D)materials via van der Waals(vdW)forces,unencumbered by lattice and processing constraints,constitutes an efficacious approach to enhance the overall optoelectronic performance of photodetectors,due to an assortment of distinctive light-matter ***,vdW heterojunction photodetectors based on transition metal dichalcogenides(TMDs)face an inevitable trade-off between low dark currents and high responsivity,curtailing the application potential of myriad novel optoelectronic components in sensing,spectral,and communication *** this study,we present the successful actualization of a highly sensitive,self-powered,and gate-tunable bipolar response *** mechanisms underlying photocurrent generation were scrutinized via bias-,power-,and position-dependent mapping photoresponse measurements,identifying the photovoltaic effect,which is attributable to the Schottky junction’s built-in electric field,as the predominant *** prototype Au-WS2-graphene photodetector exhibits a remarkable light on/off ratio of 1.2×10^(6),a specific detectivity of 6.12×10^(11)cm H^(z1/2)W^(-1)with 20μs response time at 638 *** wide gate-tunable responsivity provides an adjustability scope,ranging from 0.9 to 3.1 A W^(-1).Notably,the device demonstrates an exceptional linear photocurrent response,with a linear dynamic range(LDR)value approximating 130 dB,which significantly surpasses that of other photodetectors based on TMDs.

关键词： WS2/graphene van der Waals heterojunction gate-tunable bipolar response

Emotion Detection Using ECG Signals and a Lightweight CNN Model

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Computer Systems Science & engineering 2024年第5期48卷 1193-1211页

作者： Amita U.Dessai Hassanali G.Virani Department of electronics and Telecommunication engineering Goa College of EngineeringGoa UniversityPonda403401India

Emotion recognition is a growing field that has numerous applications in smart healthcare systems and Human-Computer Interaction(HCI).However,physical methods of emotion recognition such as facial expressions,voice,and text data,do not always indicate true emotions,as users can falsify *** the physiological methods of emotion detection,Electrocardiogram(ECG)is a reliable and efficient way of detecting ***-enabled smart bands have proven effective in collecting emotional data in uncontrolled *** use deep machine learning techniques for emotion recognition using ECG signals,but there is a need to develop efficient models by tuning the ***,most researchers focus on detecting emotions in individual settings,but there is a need to extend this research to group settings aswell since most of the emotions are experienced in *** this study,we have developed a novel lightweight one dimensional(1D)Convolutional Neural Network(CNN)model by reducing the number of convolution,max pooling,and classification *** optimization has led to more efficient emotion classification using *** tested the proposed model’s performance using ECG data from the AMIGOS(A Dataset for Affect,Personality and Mood Research on Individuals andGroups)dataset for both individual and group *** results showed that themodel achieved an accuracy of 82.21%and 85.62%for valence and arousal classification,respectively,in individual *** group settings,the accuracy was even higher,at 99.56%and 99.68%for valence and arousal classification,*** reducing the number of layers,the lightweight CNNmodel can process data more quickly and with less complexity in the hardware,making it suitable for the implementation on the mobile phone devices to detect emotions with improved accuracy and speed.

关键词： Emotions AMIGOS ECG lightweight 1D CNN

Thermodynamics of charged black holes in Maxwell-dilaton-massive gravity

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Chinese physics C 2024年第7期48卷 232-243页

作者：岳瑞宏钱凯强刘博邹德成 Center for Gravitation and Cosmology College of Physical Science and TechnologyYangzhou UniversityYangzhou 225009China School of physics Northwest UniversityXi'an 710127China School of physics and Information Science Shaanxi University of Science and TechnologyXi'an 710021China college of physics and Communication electronics Jiangxi Normal UniversityNanchang 330022China

Considering the nonminimal coupling of the dilaton field to the massive graviton field in Maxwelldilaton-massive gravity,we obtain a class of analytical solutions of charged black holes,which are neither asymptotically flat nor(A)*** calculated thermodynamic quantities,such as mass,temperature,and entropy,verify the validity of the first law of black hole ***,we further investigate the critical behaviors of these black holes in the grand canonical and canonical ensembles and find a novel critical phenomenon never before observed,known as the"reverse"reentrant phase transition with a tricritical *** implies that the system undergoes a novel"SBH-LBH-SBH"phase transition process and is the reverse of the"LBH-SBH-LBH"process observed in reentrant phase transitions.

关键词： Maxwell-dilaton-massive gravity charged black hole reverse reentrant phase transition VdW-like phase transitions

Unlocking high-efficiency oxygen evolution reaction through Co-N coordination engineering in Co@N-doped porous carbon core–shell nanoparticles

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Nano Research 2024年第8期17卷 7068-7076页

作者： Shucheng Liu Yu Shuai Xiaosi Qi Zhao Ding Yi Liu college of Big Data and Information engineering Guizhou UniversityGuiyang 550025China college of physics Guizhou Province Key Laboratory for Photoelectrics Technology and ApplicationGuizhou UniversityGuiyang 550025China

Modulation of metal sites coordination can significantly refine the electronic architecture of catalysts,thereby improving their catalytic *** work successfully developed a core–shell Co@N-doped porous carbon(Co@NC)catalyst by pyrolyzing the COF/MOF(IISERP-COF3/ZIF-67)composite in an inert *** Co@NC catalyst exhibited impressive oxygen evolution reaction(OER)performance,with a small overpotential of 304 mV and a modest Tafel slope of 88.6 mV·dec^(−1) in a 1 M KOH,alongside remarkable stability,maintaining 98.5%of its activity over 13 *** role of IISERP-COF3 was pivotal in preventing Co atom aggregation during the ZIF-67 pyrolysis,which facilitated the creation of mesopores for enhanced mass transport and ***,it effectively modulated the Co-N coordination to fine-tune the electronic structure,thereby optimizing the catalyst's capacity for adsorption of intermediates and boosting its intrinsic *** functional theory(DFT)studies corroborate that the exceptional OER efficiency of Co@NC can be linked to the enhanced Co-N coordination,optimizing the localized electronic structure at the Co active *** study not only proposes an innovative approach for optimizing COF/MOF as effective electrocatalysts but also clears the path for the emergence of affordable,high-performance alternatives to precious metal-based catalysts,marking a significant advancement in sustainable energy technologies.

关键词： covalent organic framework(COF) metal-organic framework(MOF) core-shell structure catalysts oxygen evolution reaction

AlScSbN:An opportunity for ferroelectric semiconductor field effect transistor

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Science China(physics,Mechanics & Astronomy) 2024年

作者： Shujin Guo Xianghua Kong Hong Guo college of physics and Electronic engineering Center for Computational Sciences Sichuan Normal University college of physics and optoelectronic engineering Shenzhen University Department of physics Mc Gill University

For the in-memory computation architecture, a ferroelectric semiconductor field-effect transistor （FeSFET） incorporates ferroelectric material into the FET channel to realize logic and memory in a single device. The emerging group Ⅲ nitride material Al1-xScxN provides an excellent platform to explore FeSFET, as this material has significant electric polarization, ferroelectric switching, and high carrier mobility. However, steps need to be taken to reduce the large band gap of～5 e V of Al1-xScxN to improve its transport property for in-memory logic applications. By state-of-the-art first principles analysis, here we predict that alloying a relatively small amount （less than～5%） of Sb impurities into Al1-xScxN very effectively reduces the band gap while maintaining excellent ferroelectricity. We show that the co-doped Sb and Sc act cooperatively to give a significant band bowing leading to a small band gap of～1.76 eV and a large polarization parameter～0.87 C/m2, in the quaternary Al1-xScx Sby N1-y compounds. The Sb impurity states become more continuous as a result of interactions with Sc and can be used for impurity-mediated transport. Based on the Landau-Khalatnikov model, the Landau parameters and the corresponding ferroelectric hysteresis loops are obtained for the quaternary compounds. These findings indicate that Al1-xScxSbyN1-yis an excellent candidate as the channel material of FeSFET.

关键词：

Full-Stokes metasurface polarimetry requiring only a single measurement

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Photonics Research 2024年第3期12卷 514-521页

作者： CHENGLONG ZHENG HUI LI JINGYU LIU MENGGUANG WANG HUAPING ZANG YAN ZHANG JIANQUAN YAO Key Laboratory of Material physics Ministry of EducationSchool of Physics and MicroelectronicsZhengzhou UniversityZhengzhou 450052China Key Laboratory of opto-electronics Information Technology(Tianjin University) Ministry of EducationSchool of Precision Instruments and Opto-Electronics EngineeringTianjin UniversityTianjin 300072China Beijing Key Laboratory for Metamaterials and Devices Key Laboratory of Terahertz OptoelectronicsMinistry of Educationand Beijing Advanced Innovation Center for Imaging TechnologyDepartment of PhysicsCapital Normal UniversityBeijing 100048China State Key Laboratory of Modern Optical Instrumentation College of Optical Science and EngineeringZhejiang UniversityHangzhou 310027China

Polarization is crucial in various fields such as imaging,sensing,and substance detection.A compact,fast,and accurate polarization detection device is vital for these ***,we demonstrate a multifocus metalens for terahertz polarization detection that requires only a single measurement to obtain complete polarization parameters and reconstruct the polarization state of the incident *** individual subarrays of this metalens convert each of the six polarized components into the same polarization,which in turn links the Stokes parameters to these six *** incident linear polarizations and elliptical polarizations are characterized by Stokes parameters and polarization *** and experimental results show that the scheme can accurately detect the incident polarization with a single *** proposed metasurface polarimetry may find applications in the fields of real-time terahertz detection and integrated optics.

关键词： field incident polar

Controllable optical bistability in a Fabry-Pérot cavity with a nonlinear three-dimensional Dirac semimetal

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Chinese physics B 2024年第3期33卷 441-446页

作者：袁红霞李佳雪马奇军田海山叶云洋罗文昕吴杏华蒋乐勇 School of physics and electronics Hunan Normal UniversityChangsha 410081China School of Intelligent Manufacturing and Electronic engineering Wenzhou University of TechnologyWenzhou 325035China Key Laboratory for Microstructural Functional Materials of Jiangxi Province College of ScienceJiujiang UniversityJiujiang 332005China

Optical bistability(OB)is capable of rapidly and reversibly transforming a parameter of an optical signal from one state to another,and homologous nonlinear optical bistable devices are core components of high-speed all-optical communication and all-optical *** this paper,we theoretically investigated the controllable OB from a Fabry-Pérot(FP)cavity with a nonlinear three-dimensional Dirac semimetal(3D DSM)in the terahertz *** OB stems from the third-order nonlinear bulk conductivity of the 3D DSM and the resonance mode has a positive effect on the generation of *** FP cavity structure is able to tune the OB because the transmittance and the reflectance can be modulated by the Fermi energy of the 3D *** believe that this FP cavity configuration could provide a reference concept for realizing tunable bistable devices.

关键词： optical bistability Dirac semimetal Fabry-Pérot cavity