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Friction 2024年第11期12卷 2441-2457页

作者： Zhuocheng li Enhui ZHANG Weimin li Haichao liU State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Zibo Innovation center of High-End Synthetic Lubricating Materials Zibo 255000China

Deep eutectic solvents(DESs)are acknowledged as a novel class of functional *** share similar physical properties with ionic liquids(ILs)and have the potential to be a novel class of *** this study,two DESs,namely tetrabutylammonium chloride-decanoic acid DES(c4-DES)and methyl tricaprylmethylammonium chloride-decanoic acid DES(c8-DES),were synthesized,and their physico-chemical properties and tribological performances were ***-analysis of the rubbing surfaces used multiple techniques to gain insights into the lubrication *** show that the coefficient of friction(cOF)and wear were reduced by approximately 29%and 91%for the c4-DES,and 36%and 94%for the c8-DES,compared to an ester base *** friction reduction behavior of the DESs is attributed to the monolayer adsorption of the polar group in the decanoic acid(DEAc),whose effectiveness is affected by the component of the ammonium salts in the DESs and the operating *** addition to the adsorbed film,worn surface analysis revealed that an ultra-thin tribochemical film with a thickness of 3–7 nm was formed on the surfaces lubricated with the *** composition of the film was studied,and the lubrication mechanisms of the two DESs were discussed.

关键词： deep eutectic solvent(DES) lubricants tribological performance boundary lubrication

Low-temperature graphitization of lignin via co-assisted electrolysis in molten salt

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Green Energy & Environment 2024年第9期9卷 1449-1458页

作者： Shijie li Wei-li Song Xue Han Qingqing cui Yan-li Zhu Shuqiang Jiao Institute of Advanced Structure Technology Beijing Institute of Technology State Key Laboratory of Advanced Metallurgy University of Science and Technology Beijing State Key Laboratory of Explosion Science and Technology Beijing Institute of Technology

The ever-growing energy demand and environmental issues have stimulated the development of sustainable energy ***,an efficient and environmentally friendly electrochemical transformation technology was proposed to prepare highly graphitized carbon materials from an abundant natural resource-lignin （LG）.The preparation process mainly includes pyrolytic carbonization of raw LG material and electrochemical conversion of amorphous carbon ***,with the assistance of co catalyst,the graphitization degree of the products was significantly improved,in which the mechanism was the removal of heteroatoms in LG and the rearrangement of carbon atoms into graphite ***,tunable microstructures （nanoflakes） under catalytic effects could also be observed by controlling the electrolytic *** with the products cN1 （without catalyst） and cN5 （with 10%catalyst）,the specific surface area are 158.957 and202.246 m2g-1,*** used as the electrode material for lithium-ion batteries,cN5 delivered a competitive specific capacity of～350 m Ah g-1（0.5 c） compared with commercial *** strategy proposed in this work provides an effective way to extract value-added graphite materials from lignin and can be extended to the graphitization conversion of any other amorphous carbon precursor materials.

关键词： lignin Graphitic carbon Electrochemical conversion lithium-ion batteries

Multichannel coupling induced topological insulating phases with full multimerization

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Photonics Research 2024年第3期12卷 491-498页

作者： JUN li YAPING YANG c-M.HU MOE Key Laboratory of Advanced Micro-Structured Materials School of Physics Science and EngineeringTongji UniversityShanghai 200092China Department of Physics and Astronomy University of ManitobaWinnipegManitoba R3T 2N2Canada

We propose and experimentally realize a class of quasi-one-dimensional topological lattices whose unit cells are constructed by coupled multiple identical resonators,with uniform hopping and inversion *** the presence of coupling-path-induced effective zero hopping within the unit cells,the systems are characterized by complete multimerization with degenerate-1 energy edge states for open boundary condition.

关键词： symmetry topological coupling

Multipartite oil-flower/oil-bee mutualisms involving male-bee-pollinated orchids in tropical Asia

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National Science Review 2024年第5期11卷 105-107页

作者： Meng Zhang li-Bing Jia Susanne S.Renner Zhi-Xi Tian Xiao-An Wang Jiang-Yun Gao Yi-Bo Luo Antonio J.c.Aguiar Huan-li Xu Shuang-Quan Huang Institute of Evolution and Ecology School of Life Sciences Central China Normal University Department of Biology Washington University State Key Laboratory for conservation and Utilization of Bio-resources in Yunnan Yunnan University State Key Laboratory of Systematic and Evolutionary Botany Institute of Botany Chinese Academy of Sciences Department of Zoology University of Brasília Department of Entomology College of Plant Protection China Agricultural University

Most animal-pollinated flowers offer nectar or pollen as a reward to their pollinators. A small fraction, however, have switched to other rewards, such as fatty oils offered in glandular hairs or just below the epidermis. This type of reward has evolved in some 150 genera in at least 11 families, including South American and African Orchidaceae [1,2]. Oiloffering flowers are exploited by a few hundred species of oil-collecting bees in temperate and tropical biomes on all continents except Antarctica [1,2]. Oil bees depend obligatorily on floral oil for cell lining and as larval food [3,4], which is why oil collecting usually is confined to female bees.

关键词： cTENOPLEcTRINI HYMENOPTERA DENDROBIUM APIDAE

Optimal pivot path of the simplex method for linear programming based on reinforcement learning

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Science china Mathematics 2024年第6期67卷 1263-1286页

作者： Anqi li Tiande Guo congying Han Bonan li Haoran li School of Mathematical Sciences University of Chinese Academy of SciencesBeijing100049China

Based on the existing pivot rules,the simplex method for linear programming is not polynomial in the worst ***,the optimal pivot of the simplex method is *** this paper,we propose the optimal rule to find all the shortest pivot paths of the simplex method for linear programming problems based on Monte carlo tree ***,we first propose the SimplexPseudoTree to transfer the simplex method into tree search mode while avoiding repeated basis ***,we propose four reinforcement learning models with two actions and two rewards to make the Monte carlo tree search suitable for the simplex ***,we set a new action selection criterion to ameliorate the inaccurate evaluation in the initial *** is proved that when the number of vertices in the feasible region is c_(n)^(m),our method can generate all the shortest pivot paths,which is the polynomial of the number of *** addition,we experimentally validate that the proposed schedule can avoid unnecessary search and provide the optimal pivot ***,this method can provide the best pivot labels for all kinds of supervised learning methods to solve linear programming problems.

关键词： simplex method linear programming pivot rules reinforcement learning

Humanoid robot heads for human-robot interaction:A review

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Science china(Technological Sciences) 2024年第2期67卷 357-379页

作者： li Yi ZHU liXiang ZHANG ZiQian GUO MingFei li ZhiXin li YanBiao HASHIMOTO Minoru Key Laboratory of Special Purpose Equipment and Advanced Processing Technology of Ministry of Education Zhejiang University of TechnologyHangzhou 310023China Zhejiang Provincial Key Laboratoryof Special Purpose Equipment and Advanced Processing Technology Zhejang Universityof Technology Hangzhou 310023 China Faculy of Textile Science and Technology Shinshu UniversityUeda 386-8567Japan

The humanoid robot head plays an important role in the emotional expression of human-robot interaction(HRI).They are emerging in industrial manufacturing,business reception,entertainment,teaching assistance,and tour *** recent years,significant progress has been made in the field of humanoid ***,there is still a lack of humanoid robots that can interact with humans naturally and *** review comprises a comprehensive survey of state-of-the-art technologies for humanoid robot heads over the last three decades,which covers the aspects of mechanical structures,actuators and sensors,anthropomorphic behavior control,emotional expression,and human-robot ***,the current challenges and possible future directions are discussed.

关键词： humanoid robot head anthropomorphic behaviors emotional expression human-robot interaction

LPcS Ni-Zn-Al_(2)O_(3) Intermediate Layer Enhanced SPS Nicr-cr_(3)c_(2) coating with Higher corrosion and Wear Resistances

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Journal of Wuhan University of Technology(Materials Science) 2024年第1期39卷 188-195页

作者：白杨 li Yan XING Lukuo li Xiangbo WANG Zhenhua State Key Laboratory of Marine coatings Marine Chemical Research Institute Co.Ltd.Qingdao 266071China college of Mechanical and Electrical Engineering University of China Petroleum(East China)Qingdao 266580China Science and Technology on Marine corrosion and Protection Laboratory Luoyang Ship Materials Research InstituteQingdao 266101China

The double-layer Nicr-cr_(3)c_(2)/Ni-Zn-Al_(2)O_(3) coatings with sufficient corrosion and wear resistance were prepared on low carbon steel *** intermediate layers Ni-Zn-Al_(2)O_(3) were fabricated by using low-pressure cold spray (LPcS) method to improve the salt fog corrosion resistance properties of the supersonic plasma spray (SPS) Nicr-cr_(3)c_(2) *** friction and wear performance for the double-layer and single-layer Nicr-cr_(3)c_(2) coatings were carried out by line-contact reciprocating sliding,*** with the coating surface analysis techniques,the effect of the salt fog corrosion on the tribological properties of the double-layer coatings was *** results showed that the double-layer coatings exhibited better wear resistance than that of the single-layer coatings,due to the better corrosion resistance of the intermediate layer;the wear mass losses of the double-layer coatings was reduced by 70%than that of the single layer coatings and the wear mechanism of coatings after salt fog corrosion conditions is mainly corrosion wear.

关键词： low-pressure cold spray Nicr-cr_(3)c_(2)coating wear behavior salt fog corrosion

Erosion-induced recovery cO_(2) sink offset the horizontal soil organic carbon removal at the basin scale

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Science china Earth Sciences 2024年第6期67卷 2019-2033页

作者： lingxia WANG Xiaodong NIE Jiaqi li Yaojun liU Hui WANG Yazhe li Zhongwu li School of Geographic Science Hunan Normal UniversityChangsha 410081China Institute of Interdisciplinary Studies Hunan Normal University and Hunan Provincial Key Laboratory for Eco-environmental Changes and Carbon Sequestration of the Dongting Lake BasinChangsha 410081China college of Environmental Science and Engineering Hunan University and Key Laboratory of Environmental Biology and Pollution Control(Hunan University)Ministry of EducationChangsha 410082China

To improve soil carbon sequestration capacity,the full soil carbon cycle process needs to be understood and *** is essential to evaluate whether water erosion acts as a net source or sink of atmospheric cO_(2)at the basin scale,which encompasses the entire hydrological *** study introduced an approach that combined a spatially distributed sediment delivery model and biogeochemical model to estimate the lateral and vertical carbon fluxes by water erosion at the basin *** this coupling model to the Dongting Lake Basin,the results showed that the annual average amount of soil erosion during 1980-2020 was 1.33×10^(8)t,displaying a decreasing trend followed by a slight *** 12% of the soil organic carbon displacement was ultimately lost in the riverine systems,and the rest was deposited downhill within the *** average lateral soil organic carbon loss induced by erosion was 8.86×10^(11)g c in 1980 and 1.50×10^(11)g c in 2020,with a decline rate of 83%.A net land sink for atmospheric cO_(2)of 5.54×1011g c a^(-1)occurred during erosion,primarily through sediment burial and dynamic ***,ecological restoration projects and tillage practice policies are still significant in reducing erosion,which could improve the capacity of the carbon sink for recovery beyond the rate of horizontal carbon ***,our model enables the spatial explicit simulation of erosion-induced carbon fluxes using costeffective and easily accessible input data across large spatial scales and long ***,it offers a valuable tool for predicting the interactions between carbon dynamics,land use changes,and future climate.

关键词： Water erosion Sediment transfer Lateral soil carbon loss Land-atmosphere cO_(2) flux Dongting Lake Basin

concentration breaking on two optimization problems

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Science china Mathematics 2024年第7期67卷 1555-1570页

作者： Yong Huang Qinfeng li Qiuqi li School of Mathematics Hunan UniversityChangsha410082China

In the present paper, we study the boundary concentration-breaking phenomena on two thermal insulation problems considered on lipschitz domains, based on Serrin's overdetermined result, the perturbation argument, and a comparison of Laplacian eigenvalues with different boundary conditions. Since neither of the functionals in the two problems is c^(1), another key ingredient is to obtain the global H?lder regularity of minimizers of both problems on lipschitz domains. Also, the exact dependence on the domain of breaking thresholds is given in the first problem, and the breaking values are obtained in the second problem on ball domains, which are related to 2π in dimension 2.

关键词： spectral inequalities symmetry breaking Laplacian eigenvalue

Development in oxide metallurgy for improving the weldability of high -strength low-alloy steel-combined deoxidizers and microalloying elements

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International Journal of Minerals,Metallurgy and Materials 2024年第6期31卷 1263-1284页

作者： Tingting li Jian Yang State Key Laboratory of Advanced Special Steel School of Materials Science and EngineeringShanghai UniversityShanghai 200444China

The mechanisms of oxide metallurgy include inducing the formation of intragranular acicular ferrite(IAF)using micron-sized inclusions and restricting the growth of prior austenite grains(PAGs)by nanosized particles during *** chaotically oriented IAF and refined PAGs inhibit crack initiation and propagation in the steel,resulting in high impact *** work summarizes the com-bined effect of deoxidizers and alloying elements,with the aim to provide a new perspective for the research and practice related to im-proving the impact toughness of the heat affected zone(HAZ)during the high heat input *** complex deoxidation with other strong deoxidants,such as Mg,ca,Zr,and rare earth metals(REMs),can improve the toughness of the heat-affected zone(HAZ)by re-fining PAGs or increasing IAF ***,it is difficult to identify the specific phase responsible for IAF nucleation because ef-fective inclusions formed by complex deoxidation are usually *** alloying elements,such as c,Si,Al,Nb,or cr,con-tents can impair HAZ toughness.A high c content typically increases the number of coarse carbides and decreases the potency of IAF ***,cr,or Al addition leads to the formation of undesirable *** reduces the high-temperature stability of the ***,V,and B can enhance HAZ ***-containing precipitates present good thermal *** or V(c,N)is ef-fective in promoting IAF nucleation due to its good coherent crystallographic relationship with *** formation of the B-depleted zone around the inclusion promotes IAF *** interactions between alloying elements are complex,and the effect of adding dif-ferent alloying elements remains to be *** the future,the interactions between various alloying elements and their effects on ox-ide metallurgy,as well as the calculation of the nucleation effects of effective inclusions using first principles calculations will become the focus of

关键词： oxide metallurgy technology heat affected zone high-strength low-alloy steel intragranular acicular ferrite microalloying element