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Journal of Bionic Engineering 2024年第2期21卷 821-841页

作者： Vipin Pachouri Pushparaj mani Pathak Indian Institute of Technology Roorkee Roorkee247667India

Continuum manipulators(CM)are soft and flexible manipulators with large numbers of degrees of freedom and can perform complex tasks in an unstructured ***,their deformability and compliance can deviate distal tip under uncertain external *** address this challenge,a novel tension-based control scheme has been proposed to modulate the stiffness of a tendon-driven CM,reducing the tip position errors caused by uncertain external *** minimize the tip position error,a virtual spring is positioned between the deviated and the desired tip *** proposed algorithm corrects the manipulator deviated tip position,improving tension distribution and stiffness profile,resulting in higher stiffness and better *** corresponding task space stiffness and condition numbers are also computed under different cases,indicating the effectiveness of the tension control scheme in modulating the manipulator's *** validation conducted on an in-house developed prototype confirms the practical feasibility of the proposed approach.

关键词： Continuum arm Hyper-redundant robots Variable stiffness manipulator Tension-based control Mechatronic systems

Contrasting physical mechanisms of yellowfin tuna fluctuations between the western and eastern Indian Ocean

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Journal of Oceanology and Limnology 2024年第3期42卷 960-971页

作者： Peng LIAN le GAO Key Laboratory of Ocean Observation and Forecasting and Key Laboratory of Ocean Circulation and Waves Institute of OceanologyChinese Academy of SciencesQingdao 266071China University of Chinese Academy of sciences Beijing 100049China Laboratory for Ocean Dynamics and Climate Laoshan LaboratoryQingdao 266061China

As an economically critical pelagic migratory species,yellowfin tuna(Thunnus albacores,YFT)is very sensible to physical and environmental conditions,such as sea surface temperature(ssT),ocean heat content(OHC),and the mixed layer depth(MLD).We investigated the impact of ssT,OHC,and MLD on fluctuations of YFT catch in the western/eastern Indian Ocean using the long time series of 63-year environmental and YFT *** found that the impact of ssT on YFT was heavily overestimated in the past,and MLD plays a more critical role in the YFT catch *** the MLD deepens(>34.8 m),ssT was more influential in predicting the catches of YFT than OHC in the western Indian Ocean,and OHC was more critical to YFT than ssT in the eastern Indian ***,when the MLD shallows(s more vital to predict the catch per unit effort(CPUE)of YFT than ssT/OHC in the *** 2000,there was an asynchronous pattern of YFT CPUE induced by higher frequency variations and ocean hiatus of ssT/OHC signals in the western and eastern Indian Oceans *** impact of the subsurface hiatus may induce the decrease of YFT in the eastern Indian *** above findings clarified a non-stationary relationship between the environmental factors and catches of YFT and provided new insights into variations in YFT abundance.

关键词： yellowfin tuna Indian Ocean sea surface temperature(ssT) ocean heat content(OHC) mixed layer depth(MLD) hiatus

Impacts of central-Pacific El Niño and physical drivers on eastern Pacific bigeye tuna

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Journal of Oceanology and Limnology 2024年第3期42卷 972-987页

Bigeye tuna Thunnus obesus is an important migratory species that forages deeply,and El Niño events highly influence its distribution in the eastern Pacific *** sea surface temperature is widely recognized as the main factor affecting bigeye tuna(BET)distribution during El Niño events,the roles of different types of El Niño and subsurface oceanic signals,such as ocean heat content and mixed layer depth,remain *** conducted A spatial-temporal analysis to investigate the relationship among BET distribution,El Niño events,and the underlying oceanic signals to address this knowledge *** used monthly purse seine fisheries data of BET in the eastern tropical Pacific Ocean(ETPO)from 1994 to 2012 and extracted the central-Pacific El Niño(CPEN)indices based on Niño 3 and Niño ***,we employed Explainable Artificial Intelligence(XAI)models to identify the main patterns and feature importance of the six environmental variables and used information flow analysis to determine the causality between the selected factors and BET ***,we analyzed Argo datasets to calculate the vertical,horizontal,and zonal mean temperature differences during CPEN and normal years to clarify the oceanic thermodynamic structure differences between the two types of *** findings reveal that BET distribution during the CPEN years is mainly driven by advection feedback of subsurface warmer thermal signals and vertically warmer habitats in the CPEN domain area,especially in high-yield fishing *** high frequency of CPEN events will likely lead to the westward shift of fisheries centers.

关键词： bigeye tuna central-Pacific El Niño(CPEN) ocean heat content Argo explainable artificial intelligence(XAI) information flow

Dynamic response of honeycomb-FGs shells subjected to the dynamic loading using non-polynomial higher-order IGA

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Defence Technology（防务技术） 2024年第7期37卷 149-161页

作者： Pham Binh le Trung-Thanh Tran Faculty of Mechanical Engineering Le Quy Don Technical UniversityHanoiViet Nam

The main goal of this study is to use higher-order isogeometric analysis(IGA)to study the dynamic response of sandwich shells with an auxetic honeycomb core and two different functionally graded materials(FGM)skin layers(namely honeycomb-FGs shells)subjected to dynamic ***'s non-polynomial higher-order shear deformation theory(HsDT)is used due to its simplicity and *** governing equation is derived from Hamilton's *** verifying the present approach,the effect of input parameters on the dynamic response of honeycomb-FGs shells is carried out in detail.

关键词： IGA Elastic foundation Dynamic response FGM Auxetic honeycomb shell

Heat Transfer and Flow structure of a Turbine Blade's Air-cooled leading Edge Considering Different Hole shapes and Additional Flow Angles

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Journal of Thermal science 2024年第4期33卷 1421-1442页

作者： QIN Runxuan ZHOU Xun WANG songtao CAI le school of Energy science and Engineering Harbin Institute of TechnologyHarbin150001China

A numerical study is conducted to elucidate the impact of hole shapes and additional flow angles on the flow structure of the coolant and temperature field in the leading edge area of the gas turbine *** typical hole shapes are considered for the GE-E3 *** impact of the additional flow angle(E)within each hole shape on the temperature field is *** results indicate that for the leading edge area and suction surface,the fan-shaped hole case performs best in decreasing temperatures,with a decrease of about 43 *** is mainly due to the fact that the fan-shaped hole has the maximum expansion in hole spanwise *** the pressure surface,the console hole case performs best in decreasing temperatures,with a maximum reduction of about 47.2 *** influence of E on the surface temperature at leading edge area varied between the different hole *** the cylinder hole and console hole,the E=-20°case has the lowest area-averaged *** both the fan-shaped hole and the 7-7-7 shaped hole are expansion holes,the pattern of variation of the leading edge area temperature with increasing E is similar for the fan-shaped hole case and 7-7-7 shaped hole *** E=20°case shows the lowest spanwise-averaged temperature near the hole outlet,and the E=-20°case shows the lowest spanwise-averaged temperature further downstream.

关键词： film cooling GE-E3 turbine rotor blade conjugate heat transfer leading edge

Nonlinear Coupling of Kinetic Alfvén Waves and Ion Acoustic Waves in the Inner Heliosphere

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Research in Astronomy and Astrophysics 2024年第10期24卷 141-158页

作者： mani K.Chettri Vivek shrivastav Rupak Mukherjee Nidhi Gaur R.P.sharma Hemam D.singh Department of Physics Sikkim UniversityGangtokSikkimIndia DAV Public school Sector 14GurugramHaryanaIndia Plasma simulation Laboratory Department of Energy Science and EngineeringIndian Institute of Technology DelhiDelhiIndia

We study the nonlinear coupling of kinetic Alfvén waves with ion acoustic waves applicable to the Earth’s radiation belt and near-sun streamer belt solar wind using dynamical equations in the form of modified Zakharov *** simulations show the formation of magnetic field filamentary structures associated with density humps and dips which become turbulent at later times,redistributing the energy to higher *** magnetic power spectra exhibit an inertial range Kolmogorov-like spectral index value of-5/3 for k_(⊥)ρ_(i)steeper dissipation range spectra with indices~-3 for the radiation belt case and~-4 for the nearsun streamer belt solar wind case,here k_(⊥)andρ_(i)represent the wavevector component perpendicular to the background magnetic field and the ion thermal gyroradius,*** quasilinear theory in terms of the Fokker-Planck equation in the region of wavenumber turbulent spectra,we find the particle distribution function flattening in the superthermal tail population which is the signature of particle energization and plasma heating.

关键词： sun:chromosphere sun:corona sun:heliosphere

Prognostic value of N-terminal pro B-type natriuretic peptide and troponin Ⅰ in children with dengue shock syndrome

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Asian Pacific Journal of Tropical Medicine 2024年第4期17卷 166-172页

作者： Truyen Phuoc le Phung Nguyen The Nguyen University of Medicine and Pharmacy at Ho Chi Minh city Ho Chi Minh CityVietnam Children's Hospital 1 Ho Chi Minh CityVietnam

Objective:To investigate the contribution of N-terminal pro B-type natriuretic peptide(NT-pro BNP)and troponin Ⅰ to mortality in children with dengue shock ***:A longitudinal study was conducted on children with dengue shock syndrome in a hospital in southern *** clinical histories,physical examinations,and laboratory parameters,including NT-pro BNP and troponin Ⅰ,were recorded.A comparison between survival and non-survival was carried out to identify factors influencing ***:A total of 107 patients with a median age of 9 years were included in the *** them,63.6%(68/107)presented with compensated shock,36.4%(39/107)had hypotensive shock,23.4%(25/107)required mechanical ventilation,and 12.1%(13/107)*** NT-pro BNP levels were 3.9 pmol/L(IQR:1.9,10.3)and 15.2 pmol/L(5.8,46.3),while the median high sensitivity troponin Ⅰ levels were 20 pg/L(6,95)and 62 pg/L(12,325)at the first and second measurements,*** mortality group exhibited higher rates of hypotensive shock,prolonged shock,lactate levels,liver damage,NT-pro BNP,and troponin Ⅰ *** shock(OR 12.96,95%CI 2.70-62.30,P=0.004),prolonged shock(OR 39.40,95%CI 6.68-232.70,PsT>1000 IU/L(OR 9.50,95%CI 2.63-34.34,P=0.041),and NT-pro BNP>7 pmol/L(OR 44.40,95%CI 5.44-362.20,P=0.001)were identified as predictive factors for mortality in dengue shock ***:The NT-pro BNP level could serve as a potential biomarker for predicting mortality in children with dengue shock syndrome.

关键词： Dengue shock syndrome Cardiac enzyme NT-pro BNP TroponinⅠ

Theoretical study of the nonlinear force-loading control in single-molecule stretching experiments

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Communications in Theoretical Physics 2024年第4期76卷 167-175页

作者： Xingyu Qi Zilong Guo shimin le Hu Chen Research Institute for Biomimetics and soft Matter Fujian Provincial Key Lab for Soft Functional Materials ResearchDepartment of PhysicsXiamen UniversityXiamen 361005China Center of Biomedical Physics Wenzhou InstituteUniversity of Chinese Academy of SciencesWenzhou 325000China

Force spectrum measurements with constant loading rates are widely used in single-molecule manipulation experiments to study the mechanical stability and force response of ***-dependent transition rates can be obtained from the transition force distribution,but it is limited to the force range with non-zero force *** constant loading rate control can be realized with magnetic tweezers,the loading rate range is limited due to the slow movement of permanent ***-linear exponential and exponential squared force loading functions are more feasible in magnetic tweezers,while there is no theoretical result available for these two kinds of non-linear force loading *** this study,we solved the unfolding process of a protein following Bell's model under nonlinear exponential and exponential squared force loading functions,which offer a broader range of unfolding force distribution compared to the traditional constant loading rate ***,we derived two force loading functions,which can produce uniform unfolding force *** research contributes fundamental equations for the analysis of experimental data obtained through single-molecule manipulation under nonlinear force loading controls,paving the way for the use of nonlinear force control in magnetic tweezer experiments.

关键词： single-molecule manipulation magnetic tweezers force loading transition rates force distribution

Disturbances rejection optimization based on improved two-degree-of-freedom LADRC for permanent magnet synchronous motor systems

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Defence Technology（防务技术） 2024年第3期33卷 518-531页

作者： Chenggang Wang Jianhu Yan Wenlong Li Liang shan le sun school of Automation Nanjing University of Science and TechnologyNanjing 210094China

Permanent magnet synchronous motor(PMsM)speed control systems with conventional linear active disturbance rejection control(CLADRC)strategy encounter issues regarding the coupling between dynamic response and disturbance suppression and have poor performance in suppressing complex nonlinear *** order to address these issues,this paper proposes an improved two-degree-of-freedom LADRC(TDOF-LADRC)strategy,which can enhance the disturbance rejection performance of the system while decoupling entirely the system's dynamic and anti-disturbance performance to boost the system robustness and simplify controller parameter *** models that consider total disturbances are developed to design the TDOF-LADRC speed controller ***,to evaluate the control performance of the TDOF-LADRC strategy,its stability is proven,and the influence of each controller parameter on the system control performance is *** on it,a comparison is made between the disturbance observation ability and anti-disturbance performance of TDOF-LADRC and CLADRC to prove the superiority of TDOF-LADRC in rejecting ***,experiments are performed on a 750 W PMsM experimental platform,and the results demonstrate that the proposed TDOF-LADRC exhibits the properties of two degrees of freedom and improves the disturbance rejection performance of the PMsM system.

关键词： Permanent magnet synchronous motor(PMsM) Active disturbance rejection control(ADRC) Disturbance observer Two-degree-of-freedom control Anti-disturbance

Understanding the Activity Performance of Comets 38P/stephan-Oterma,64P/swift-Gehrels and C/2017 M4(ATLAs)through Broadband Photometric Observations

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Research in Astronomy and Astrophysics 2024年第8期24卷 147-156页

作者： Xuan Zhang Jin-Zhong Liu le-Tian Wang Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China

In this work,we report observations of three comets:38P/stephan-Oterma,64P/swift-Gehrels,and C/2017 M4(ATLAs),conducted with the Nanshan one-meter wide-field telescope in 2018 August and November,and *** extracted morphological features through image enhancement techniques and calculated the dust activity parameter,Afρ,along with dust mass loss rates and coma color indices using broadband photometric *** morphological analysis uncovered a spectrum of dust characteristics among the observed comets,ranging from a significant twisted structure in comet 38P/stephan-Oterma’s coma to the regular coma envelope surrounding comet 64P/*** Afρvalues varied between 148.8±0.3 cm for 64P/swift-Gehrels and1118.5±6.2 cm for C/2017 M4(ATLAs)(measured within a reference aperture radius ofρ=6″),indicating a range from moderate to high activity *** mass loss rates were estimated from 328.1 kg s^(-1)for comet 64P/swift-Gehrels to 1395.5 kg s^(-1)for comet C/2017 M4(ATLAs).The color indices of comets 38P/stephan-Oterma and C/2017 M4(ATLAs)closely resemble the average colors of active short-period comets and active longperiod comets,*** contrast,64P/swift-Gehrels exhibits a significantly bluer hue than typical Jupiter family comets.

关键词： comets general-comets individual(38P/stephan-Oterma,64P/swift-Gehrels,C/2017 M4(ATLAs))-techniques photometric