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Chinese Journal of Aeronautics 2024年第3期37卷 417-439页

作者： Dongyang SHANG Xiaopeng li Meng YIN Fanjie li School of Mechanical Engineering and Automation Northeastern UniversityShenyang 110819China Shenzhen Institute of Advanced Technology Chinese Academy of SciencesShenzhen 518055China

In space operation,flexible manipulators and gripper mechanisms have been widely used because of light weight and ***,the vibration caused by slender structures in manipulators and the parameter perturbation caused by the uncertainty derived from grasping mass variation cannot be *** existence of vibration and parameter perturbation makes the rotation control of flexible manipulators difficult,which seriously affects the operation accuracy of ***’s more,the complex dynamic coupling brings great challenges to the dynamics modeling and vibration *** solve this problem,this paper takes the space flexible manipulator with an underactuated hand(SFMUH)as the research *** dynamics model considering flexibility,multiple nonlinear elements and disturbance torque is established by the assumed modal method(AMM)and Hamilton’s principle.A dynamic modeling simplification method is proposed by analyzing the nonlinear ***’s more,a sliding mode control(SMC)method combined with the radial basis function(RBF)neural network compensation is ***,the control law is designed using a saturation function in the control method to weaken the chatter *** the help of neural networks to identify the uncertainty composition in the SFMUH,the tracking accuracy is *** results of ground control experiments verify the advantages of the control method for vibration suppression of the SFMUH.

关键词： Space flexible manipulator RBF neural network Underactuated hand Dynamic models Model simplification

Piezoelectric composite hydrogel with wireless electrical stimulation enhances motor functional recovery of spinal cord injury

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Journal of Materials Science & Technology 2024年第5期172卷 228-239页

作者： Zehao li Guanlin li Xinyu Wang Zheng Zhao State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China Sanya Science and Education Innovation Park of Wuhan University of Technology Sanya 572000China

Electrical stimulation(ES)can restore motor function after spinal cord injury(SCI).However,traditional intraspinal ES has many disadvantages,such as the need for a complex circuitry device,an external power source,and a second surgery to remove the *** materials have received increasing at-tention due to their potential to convert ambient mechanical energy into ES without an external power source or implantation of ***,a novel polydopamine(PDA)coated barium titanate(BaTiO_(3))nanoparticles(BaTiO_(3)@PDA)incorporated silk fibroin(SF)hydrogel(SFBT)was *** SFBT hy-drogel was crosslinked by horseradish peroxidase(HRP)/hydrogel peroxide(H_(2)O_(2))to integrate the piezo-electric potency of BaTiO_(3)with the thermal sensitivity of HRP/H_(2)O_(2)for SCI *** hydrogel con-taining 5%(w/v)BaTiO_(3)@PDA nanoparticles(SFBT-5),which was selected for in vivo study,exhibited a short gelation time(5 min),suitable storage modulus(925±35 Pa),and wireless ES(average current of 124 nA).Moreover,Basso-Beattie-Bresnahan(BBB)scores test and footprint analysis demonstrated that the SFBT-5 hydrogel successfully enhanced motor functional recovery of *** histopathological assess-ments,the SFBT-5 hydrogel significantly accelerated spinal cord healing,as indicated by smaller lesion cavities(∼16.7%of the SCI group).Meanwhile,the SFBT-5 hydrogel accelerated neurogenesis,facilitated axon regrowth and synapse formation,and promoted ***,this study highlights the potential of piezoelectric hydrogels for SCI regeneration.

关键词： Silk fibroin Barium titanate Piezoelectric hydrogel Spinal cord injury Electrical stimulation

Plastic deformation behavior of a Cu-10Ta alloy under strong impact loading

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Defence Technology（防务技术） 2024年第2期32卷 368-382页

作者： Ping Song Jianghai liu Wenbin li Yiming li Research Institute of Chemical Defense Academy of Military ScienceBeijing102205China Ministerial Key Laboratory of ZNDY Nanjing University of Science and TechnologyNanjing210094China

In this work,a Cu-10Ta alloy with a copper to tantalum mass ratio of 9:1 is prepared using powder metallurgy *** properties of the alloy,including density,microstructure,melting point,and constant-volume specific heat,are *** the split Hopkinson pressure bar(SHPB)and flyerplate impact experiments,the relationship between equivalent stress and equivalent plastic strain of the material is studied at temperatures of 298-823 K and under strain rates of 1×10^(-3)-5.2×10^(3)s^(-1),and the Hugoniot relationship at impact pressures of 1.46-17.25 GPa and impact velocities of 108-942 m/s is *** of the Cu-10Ta microstructure that occurs during high-strain-rate impact is *** indicate that the Cu-10Ta alloy possesses good thermal stability,and at ambient temperatures of up to 50%its melting point,stress softening of less than 15%of the initial strength is observed.A modified J-C constitutive model is employed to accurately predict the variation of yield strength with strain *** strong impact,the copper phase is identified as the primary source of plastic deformation in the Cu-10Ta alloy,while significant deformation of the high-strength tantalum particles is less ***,the longitudinal wave speed D is found to correlate linearly with the particle velocity u upon strong *** reveals that the sound speed and spallation strength of the alloy increase with increasing impact pressure.

关键词： Cu-10Ta SHPB Plastic deformation Flyer impact Hugoniot relationship

The origins of catalytic selectivity for the electrochemical conversion of carbon dioxide to methanol

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Nano Research 2024年第1期17卷 5-17页

作者： Tian Wang Yating Wang Yuhang li Chunzhong li Key Laboratory for Ultrafine Materials of Ministry of Education Shanghai Engineering Research Center of Hierarchical NanomaterialsFrontiers Science Center for Materiobiology and Dynamic ChemistrySchool of Materials Science and EngineeringEast China University of Science&TechnologyShanghai 200237China School of Chemical Engineering East China University of Science&TechnologyShanghai 200237China

The electrocatalytic conversion of carbon dioxide(CO_(2))into useful fuels and chemical feedstocks is an emerging route to alleviate global warming and reduce reliance on fossil ***(CH_(3)OH),as one of the most significant and widely used liquid fuels that can be generated by CO_(2)reduction,is essential in the chemical *** this minireview,we unravel the origins of the selective formation of CH_(3)OH via CO_(2)reduction,including catalyst composition designs,local structure modulations,and electrolyte/catalyst interface ***,the remaining challenges and perspectives for the CO_(2)-to-CH_(3)OH reduction are proposed.

关键词： methanol carbon dioxide(CO_(2))reduction reaction electrochemistry electrocatalyst catalyst-electrolyte interface

Modelling the formation and dissolution behavior of alumina agglomerate in the cryolite

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Particuology 2024年第3期86卷 211-222页

作者： Jiaqi Wang Mao li Benjun Cheng Hesong li School of Energy Science and Engineering Central South UniversityChangsha410083China

The presence of alumina agglomerates seriously affects the current efficiency of the aluminum electrolysis *** the dynamic dissolution process of agglomerates is essential to improve the current efficiency of aluminum electrolysis.A mathematical model is proposed to describe the different phenomena from the formation until complete dissolution of *** permeation and solidification processes of cryolite,a semi-analytical mathematical model is developed to formulate the formation,melting and dissolution processes of agglomerates,and the time duration for each stage is *** and heat mass transfer of agglomerates are explored based on the packing theory and mechanism of heat mass transfer in wet porous *** approach is applied to investigate the main factors affecting the dissolution stages and porosity of *** results show that the superheat has a great influence on the formation and melting stage,the diameter of agglomerates can reach 14.93 mm for 200 particles *** density decreases with the increase of agglomerated particle number,which varies in the range of 2.27-2.28 g/cm^(3).The average dissolution rate of agglomerates is about 1.83×10^(-5)-2.95×10^(-5) kg/s within the range of alumina concentration in this study.

关键词： Mathematical model Alumina agglomerate Porous media Packing theory Heatand mass transfer

Dendroclimatological study of Sabina saltuaria and Abies faxoniana in the mixed forests of the Qionglai Mountains,eastern Tibetan Plateau

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Journal of Forestry Research 2024年第1期35卷 72-82页

作者： Teng li Jianfeng Peng Tsun Fung Au Jingru li Jinbao li Yue Zhang School of Geography and Remote Sensing Guangzhou UniversityGuangzhou 510006People’s Republic of China College of Geography and Environmental Science Henan UniversityKaifeng 475004People’s Republic of China Institute for Global Change Biology School for Environment and SustainabilityUniversity of MichiganAnn ArborMIUSA Department of Ecology and Evolutionary Biology University of MichiganAnn ArborMIUSA Department of Geography University of Hong KongHong Kong SARPeople’s Republic of China HKU Shenzhen Institute of Research and Innovation Shenzhen 518057People’s Republic of China

Tree-ring chronologies were developed for Sabina saltuaria and Abies faxoniana in mixed forests in the Qionglai Mountains of the eastern Tibetan ***-growth relationship analysis indicated that the two co-exist-ing species reponded similarly to climate factors,although *** was more sensitive than *** strong-est correlation was between *** chronology and regional mean temperatures from June to *** on this relationship,a regional mean temperature from June to November for the period 1605-2016 was *** explained 37.3%of the temperature variance during th period *** major warm periods and five major cold periods were *** analysis detected significant interannual and multi-decadal *** also revealed the influence of the Atlantic Multi-decadal Oscillation,confirming its importance on climate change on the eastern Tibetan Plateau.

关键词： Tree-ring analysis Mixed forests Dendroclimatology Qionglai Mountains

Variable Selection for Generalized linear Model with Highly Correlated Covariates

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Acta Mathematica Sinica,English Series 2024年第6期40卷 1458-1480页

作者： li li YUE Wei Tao WANG Gao Rong li School of Statistics and Data Science Nanjing Audit UniversityNanjing 211815P.R.China School of Mathematics Statistics and MechanicsBeijing University of TechnologyBeijing 100124P.R.China School of Statistics Beijing Normal UniversityBeijing 100875P.R.China

The penalized variable selection methods are often used to select the relevant covariates and estimate the unknown regression coefficients simultaneously,but these existing methods may fail to be consistent for the setting with highly correlated *** this paper,the semi-standard partial covariance(SPAC)method with Lasso penalty is proposed to study the generalized linear model with highly correlated covariates,and the consistencies of the estimation and variable selection are shown in high-dimensional settings under some regularity *** simulation studies and an analysis of colon tumor dataset are carried out to show that the proposed method performs better in addressing highly correlated problem than the traditional penalized variable selection methods.

关键词： Generalized linear model highly correlated covariates Lasso penalty semi-standard partial covariance variable selection

Nanoscale Zero-Valent Iron(nZVI)for Heavy Metal Wastewater Treatment:A Perspective

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Engineering 2024年第5期36卷 16-20页

作者： Shaolin li Lei li Weixian Zhang State Key Laboratory for Pollution Control and Resource Reuse College of Environmental Science and EngineeringTongji UniversityShanghai 200092China Shanghai Institute of Pollution Control and Ecological Security Shanghai 200092China

Industries such as non-ferrous metal smelting discharge billions of gallons of highly toxic heavy metal wastewater(HMW)worldwide annually,posing a severe challenge to conventional wastewater treatment plants and harming the *** is traditionally treated via chemical precipitation using lime,caustic,or sulfide,but the effluents do not meet the increasingly stringent discharge *** issue has spurred an increase in research and the development of innovative treatment technologies,among which those using nanoparticles receive particular *** such initiatives,treatment using nanoscale zero-valent iron(nZVI)is one of the best *** nZVI is already well known for its site-remediation use,this perspective highlights its application in HMW treatment with metal *** demonstrate several advantages of nZVI in this wastewater application,including its multifunctionality in sequestrating a wide array of metal(loid)s(>30 species);its capability to capture and enrich metal(loid)s at low concentrations(with a removal capacity reaching 500 mg·g^(-1)nZVI);and its operational convenience due to its unique *** these advantages are attributable to nZVI’s diminutive nanoparticle size and/or its unique iron *** also present the first engineering practice of this application,which has treated millions of cubic meters of HMW and recovered tons of valuable metals(e.g.,Cu and Au).It is concluded that nZVI is a potent reagent for treating HMW and that nZVI technology provides an eco-solution to this toxic waste.

关键词： Nanoscale zero-valent iron Wastewater Heavy metal Resource recovery

AI enhances drug discovery and development

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National Science Review 2024年第3期11卷 52-54页

作者： Fang Bai Shiliang li Honglin li Shanghai Institute for Advanced Immunochemical Studies and School of life Science and Technology ShanghaiTech University lingang Laboratory Innovation Center for AI and Drug Discovery East China Normal University

The advent of the third wave of artificial intelligence(AI) heralds a new era in drug discovery. AI-powered techniques can be characteristic of identifying features that are difficult for humans to interpret from big ...

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Mathematical Analysis on a General Delayed HBV Model with Capsids and Two Infection Routes

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Acta Mathematicae Applicatae Sinica 2024年第2期40卷 508-525页

作者： li-li liU Hong-gang WANG Ya-zhi li Shanxi Key Laboratory of Mathematical Techniques and Big Data Analysis on Disease Control and Prevention Complex Systems Research CenterShanxi UniversityTaiyuan 030006China School of Mathematics and Statistics Qiannan Normal University for NationalitiesDuyun 558000China

Considering that HBV belongs to the DNA virus family and is hepatotropic,we model the HBV DNA-containing capsids as a *** this paper,a delayed HBV infection model is established,where the general incidence function and two infection routes including cell-virus infection and cell-cell infection are *** to some preliminaries,including well-posedness,basic reproduction number and existence of two equilibria,we obtain the threshold dynamics for the *** illustrate numerical simulations to verify the above theoretical results,and furthermore explore the impacts of intracellular delay and cell-cell infection on the global dynamics of the model.

关键词： delayed HBV model capsids general incidence function two infection routes global stability

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