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Modeling static friction behavior of elastic–plastic spherical adhesive microcontact in full-stick condition

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Friction 2024年第11期12卷 2594-2610页

作者： Guo XIANG Roman GOLTSBERG Izhak ETSION Department of Mechanical Engineering TechnionHaifa 32000Israel

The static friction behavior of an elastic–plastic spherical adhesive microcontact between a rigid flat and a deformable sphere under combined normal and tangential loading is studied by the finite element method(FEM).The contact between the sphere and the rigid flat is assumed to be full-stick,and the sliding inception is related to a loss of tangential *** intermolecular force between the rigid flat and the sphere is assessed by the Lennard–Jones(LJ)potential,which is applied to the sphere and the rigid flat by a user *** evolution of the adhesive force with tangential displacement in the full-stick condition is *** results indicate that the increasing effect of adhesive energy on the static friction coefficient gradually diminishes with an increase in the adhesive energy and the external normal ***,based on an extensive parametric study,an empirical dimensionless expression is obtained to predict the static friction coefficient of the spherical adhesive microcontact considering the intermolecular force.

关键词： adhesive spherical microcontact Lennard–Jones(LJ)potential elastic–plastic static friction

Quafu-RL:The cloud quantum computers based quantum reinforcement learning

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Chinese Physics B 2024年第5期33卷 29-34页

作者：靳羽欣许宏泽王正安庄伟峰黄凯旋时运豪马卫国李天铭陈驰通许凯冯玉龙刘培陈墨李尚书杨智鹏钱辰马运恒肖骁钱鹏顾炎武柴绪丹普亚南张翼鹏魏世杰曾进峰李行龙桂鲁金贻荣于海峰范桁刘东胡孟军 Beijing Academy of Quantum Information sciences Beijing 100193China State Key Laboratory of Low Dimensional Quantum Physics Department of PhysicsTsinghua UniversityBeijing 100084China Institute of Physics Chinese Academy of SciencesBeijing 100190China Frontier Science Center for Quantum Information Beijing 100184China School of Physical sciences University of Chinese Academy of SciencesBeijing 100190China CAS Center for Excellence in Topological Quantum Computation University of Chinese Academy of SciencesBeijing 100190China School of Mathematical sciences Nankai UniversityTianjin 300071China

With the rapid advancement of quantum computing,hybrid quantum–classical machine learning has shown numerous potential applications at the current stage,with expectations of being achievable in the noisy intermediate-scale quantum(NISQ)*** reinforcement learning,as an indispensable study,has recently demonstrated its ability to solve standard benchmark environments with formally provable theoretical advantages over classical ***,despite the progress of quantum processors and the emergence of quantum computing clouds,implementing quantum reinforcement learning algorithms utilizing parameterized quantum circuits(PQCs)on NISQ devices remains *** this work,we take the first step towards executing benchmark quantum reinforcement problems on real devices equipped with at most 136 qubits on the BAQIS Quafu quantum computing *** experimental results demonstrate that the policy agents can successfully accomplish objectives under modified conditions in both the training and inference ***,we design hardware-efficient PQC architectures in the quantum model using a multi-objective evolutionary algorithm and develop a learning algorithm that is adaptable to quantum *** hope that the Quafu-RL can be a guiding example to show how to realize machine learning tasks by taking advantage of quantum computers on the quantum cloud platform.

关键词： quantum cloud platform quantum reinforcement learning evolutionary quantum architecture search

Research progress on rolling superlubricity in solid lubricants

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Science china(Technological sciences) 2024年第7期67卷 1980-1990页

作者： LI PanPan LI HongXuan ZHU DongXiang ZHU YongQi KANG FuYan WANG Wan ZHANG YaXin LIU XiaoHong JI Li ZHOU HuiDi CHEN JianMin 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 School of Chemical Engineering Northwest Minzu UniversityLanzhou 730030China

Superlubricity is an ideal lubrication state where friction nearly vanishes between contact interfaces. It has become one of the most important research topics and approaches owing to its significance in reducing energy consumption and preventing device failures. As an efficient and universal lubricating principle capable of achieving superlubricity, rolling lubrication has attracted widespread attention in recent years. In this review, the theoretical concept of rolling lubrication and the experimental research progress of spherical/scroll structures are summarized. The review focuses on the possibility of achieving rolling lubrication using spherical/scroll structures(such as spherical fullerenes, carbon nanotubes, and formed and constructed spherical/scroll structures). The challenges in achieving rolling lubrication are summarized, and the possibility of molecular rolling lubrication,as well as its potential applications in superlubrication, are discussed.

关键词： spherical/scroll structure rolling lubrication superlubricity fullerene

Rosemary leaf powder improves egg quality, antioxidant status, gut barrier function, and cecal microbiota and metabolites of late-phase laying hens

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Animal Nutrition 2024年第2期17卷 325-334页

作者： Lianhua Zhang Junwei Ge Fei Gao Min Yang Hui Li Fei Xia Hongtong Bai Xiangshu Piao Zhiying Sun Lei Shi Key Laboratory of Plant Resources Institute of Botany Chinese Academy of Sciences china National Botanical Garden State Key Laboratory of Animal Nutrition Institute of Animal Science Chinese Academy of Agricultural Sciences College of Pharmacy Shandong University of Traditional Chinese Medicine University of Chinese Academy of sciences Beijing Jingwa Agricultural Science&Technology Innovation Center State Key Laboratory of Animal Nutrition College of Animal Science and Technology China Agricultural University

his study sought to determine the effects of rosemary leaf powder(RP) on laying performance, egg quality, serum indices, gut barrier function, and cecal microbiota and metabolites of late-phase laying hens. A total of 84 “Jing Tint 6” laying hens at 65-week old were randomly divided into 2 groups and fed either a basal diet(CON) or a basal diet supplemented with 0.3% RP. Our study revealed that RP improved the Haugh unit and decreased yolk n-6/n-3 polyunsaturated fatty acid(PUFA) ratio of laying hens,increased serum superoxide dismutase(SOD), jejunal activities of SOD and catalase(CAT), and jejunal zonula occludens-1(ZO-1) expression, as well as decreased serum tumor necrosis factor-a(TNF-a) level and jejunal TNF-a m RNA expression. Rosemary leaf powder markedly enhanced(P < 0.05) cecal abundances of Rikenellaceae, Rikenellaceae＿RC9＿gut＿group, and Turicibacter, tended to promote(P = 0.076)butyrate concentration, and reduced(P < 0.05) cecal abundances of Erysipelatoclostridiaceae, Sutterellaceae, Fusobacteriaceae, Campylobacteraceae, Sutterella, Campylobacter, and Fusobacterium, which were closely linked with Haugh unit, yolk n-6/n-3 PUFA ratio, serum SOD and TNF-a. In addition, RP altered the metabolic functions of cecal microbiota and enhanced the abundances of butyratesynthesizing enzymes, including lysine 2,3-aminomutase, β-lysine 5,6-aminomutase, and 3-oxoacid Co A-transferase. Together, 0.3% RP has the potential to enhance egg quality by partially modulating serum antioxidant status, jejunal barrier function, and cecal microbiota structure and metabolites,indicating that RP could be considered a promising feed additive to promote the production performance of late-phase laying hens.

关键词： Rosemary leaf powder Production Antioxidant status Gut health Microbial community Laying hen

Disorder-to-order transition induced by spontaneous cooling regulation in robotic active matter

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Chinese Physics B 2024年第7期33卷 96-103页

作者：侯帅旭王高马星宇汪楚云王鹏陈怀城刘雳宇王璟 Chongqing Key Laboratory of Soft Condensed Matter Physics and Smart Materials College of PhysicsChongqing UniversityChongqing 401331China Wenzhou Institute University of Chinese Academy of SciencesWenzhou 325011China School of Physical sciences University of Chinese Academy of SciencesBeijing 100049China School of Ophthalmology and Optometry Eye HospitalSchool of Biomedical EngineeringWenzhou Medical UniversityWenzhou 325035China Postgraduate Training Base Alliance Wenzhou Medical UniversityWenzhou 325035China

In classical matter systems, typical phase-transition phenomena usually stem from changes in state variables, such as temperature and pressure, induced by external regulations such as heat transfer and volume adjustment. However, in active matter systems, the self-propulsion nature of active particles endows the systems with the ability to induce unique collectivestate transitions by spontaneously regulating individual properties to alter the overall states. Based on an innovative robot-swarm experimental system, we demonstrate a field-driven active matter model capable of modulating individual motion behaviors through interaction with a recoverable environmental resource field by the resource perception and *** the simulated model, by gradually reducing the individual resource-conversion coefficient over time, this robotic active matter can spontaneously decrease the overall level of motion, thereby actively achieving a regulation behavior like the cooling-down control. Through simulation calculations, we discover that the spatial structures of this robotic active matter convert from disorder to order during this process, with the resulting ordered structures exhibiting a high self-adaptability on the geometry of the environmental boundaries.

关键词： active matter robot swarm collective-state transitions environmental self-adaptability

Two-dimensional localized modes in nonlinear systems with linear nonlocality and moiré lattices

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Frontiers of physics 2024年第4期19卷 265-273页

作者： Xiuye Liu Jianhua Zeng Center for Attosecond Science and Technology State Key Laboratory of Transient Optics and PhotonicsXi’an Institute of Optics and Precision Mechanics of Chinese Academy of SciencesXi’an 710119China University of Chinese Academy of sciences Beijing 100049China Collaborative lnnovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006China

Periodic structures structured as photonic crystals and optical lattices are fascinating for nonlinear waves engineering in the optics and ultracold atoms ***éphotonic and optical lattices—two-dimensional twisted patterns lie somewhere in between perfect periodic structures and aperiodic ones—are a new emerging investigative tool for studying nonlinear localized waves of diverse ***,a theory of two-dimensional spatial localization in nonlinear periodic systems with fractional-order diffraction(linear nonlocality)and moiréoptical lattices is ***,the flat-band feature is well preserved in shallow moiréoptical lattices which,interact with the defocusing nonlinearity of the media,can support fundamental gap solitons,bound states composed of several fundamental solitons,and topological states(gap vortices)with vortex charge s=1 and 2,all populated inside the finite gaps of the linear Bloch-wave *** the linear-stability analysis and direct perturbed simulations,the stability and instability properties of all the localized gap modes are surveyed,highlighting a wide stability region within the first gap and a limited one(to the central part)for the third *** findings enable insightful studies of highly localized gap modes in linear nonlocality(fractional)physical systems with shallow moirépatterns that exhibit extremely flat bands.

关键词： moiréoptical lattices gap solitons and vortices ultracold atoms Gross-Pitaevskii/nonlinear fractional Schrödinger equation nonlinear fractional systems

Stepping forward:T-cell redirecting bispecific antibodies in cancer therapy

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Acta Pharmaceutica Sinica B 2024年第6期14卷 2361-2377页

作者： Xiaojing Qin Wenjing Ning Han Liu Xue Liu Wenxin Luo Ningshao Xia State Key Laboratory of Vaccines for Infectious Diseases Xiang An Biomedicine LaboratorySchool of Public HealthXiamen UniversityXiamen 361102China National Institute of Diagnostics and Vaccine Development in Infectious Diseases State Key Laboratory of Molecular Vaccinology and Molecular DiagnosticsNational Innovation Platform for IndustryeEducation Integration in Vaccine Researchthe Research Unit of Frontier Technology of Structural Vaccinology of Chinese Academy of Medical SciencesXiamen UniversityXiamen 361102China

T cell-redirecting bispecific antibodies are specifically designed to bind to tumor-associated antigens,thereby engaging with CD3 on the T cell *** linkage between tumor cells and T cells actively triggers T cell activation and initiates targeted killing of the identified tumor *** antibodies have emerged as one of the most promising avenues within tumor ***,despite success in treating hematological malignancies,significant advancements in solid tumors have yet to be *** this review,we aim to address the critical challenges associated with T cellredirecting bispecific antibodies and explore novel strategies to overcome these obstacles,with the ultimate goal of expanding the application of this therapy to include solid tumors.

关键词： Bispecific antibody(BsAbs) T-cell redirecting BsAbs Tumor-associated antigens Toxicity Cytokine release syndrome Tumor microenvironment Cancer immunotherapy Combination therapy strategies

Linking nutrient resorption stoichiometry with plant growth under long-term nitrogen addition

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Forest Ecosystems 2024年第5期11卷 642-649页

作者： Aijun Xing Haihua Shen Longchao Xu Mengying Zhao Zhengbing Yan Jingyun Fang State Key Laboratory of Vegetation and Environmental Change Institute of BotanyChinese Academy of SciencesBeijing100093China University of Chinese Academy of sciences Beijing100049China Institute of Ecology College of Urban and Environmental Sciencesand Key Laboratory for Earth Surface Processes of the Ministry of EducationPeking UniversityBeijing100871China College of Ecology Taiyuan University of TechnologyShanxi030024China

Increased nitrogen(N)input can potentially lead to secondary phosphorus(P)limitation;however,it remains unclear whether differences in the plant's ability to cope with this P deficiency are related to their growth *** a long-term experiment of N addition in a boreal forest,we explored the potential role of plant nutrient resorption efficiency and its stoichiometry in mediating plant growth responses to increased N *** recorded the cover and measured the concentration and resorption efficiency of leaf N and P as well as the photosynthesis of a grass Deyeuxia angustifolia and a shrub Vaccinium *** cover of the grass *** increased with increasing N addition,while that of the shrub ***-idaea decreased with N addition rate and almost disappeared from the high-level N addition over time.P resorption efficiency(PRE)increased in *** but decreased in ***-idaea with increasing leaf N:P which was increased by N addition for both *** addition,photosynthesis increased linearly with N resorption efficiency(NRE)and PRE but was better explained by NRE:PRE,changing nonlinearly with the ratio in a hump-shaped ***,the variance(CV)of NRE:PRE for ***-idaea(123%)was considerably higher than that for ***(29%),indicating a more stable nutrient resorption stoichiometry of the *** together,these results highlight that efficient P acquisition and use strategy through nutrient resorption processes could be a pivotal underlying mechanism driving plant growth and community composition shifts under N enrichment.

关键词： Nitrogen deposition Understory layer Community shift Nutrient limitation Phosphorus resorption efficiency Stoichiometric homeostasis

Spatiotemporal variation of rainy season span and precipitation recorded by lacustrine laminated pollen in the Tibetan Plateau during the past two millennia

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Science china Earth sciences 2024年第3期67卷 789-801页

作者： Anning CUI Houyuan LU Juzhi HOU Xingqi LIU Deke XU Key Laboratory of Cenozoic Geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Innovation Academy for Earth Science Chinese Academy of SciencesBeijing 100029China College of Earth and Planetary sciences University of Chinese Academy of SciencesBeijing 100049China Group of Alpine Paleoecology and Human Adaptation State Key Laboratory of Tibetan Plateau Earth SystemResources and EnvironmentInstitute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China University of Chinese Academy of sciences Beijing 100049China Capital Normal University College of Resource Environment and Tourism Beijing 100048China

The quantitative reconstruction of the length of the rainy season and precipitation on the Tibetan Plateau(TP) is crucial for revealing the spatiotemporal evolution of the Westerlies and Asian summer monsoon, as well as its ecological and environmental effects. Accurately determining the start and end times of the rainy season on the Plateau remains *** study determined the start and end times of the rainy season in different locations on the Plateau by identifying precipitation inflection points. We calculated the duration and precipitation amount of the rainy season and established a transfer function between the modern pollen assemblages and them. Then, we reconstructed the rainy season variations in Kusai Lake(northern TP) and Jiang Co(central TP) during the past two millennia. The results showed that, the rainy season precipitation in Kusai Lake recorded five periods of high precipitation: AD 580–680, 1000–1100, 1200–1450, 1550–1780, and 1920–present, corresponding to the stages with long rainy season. The rainy season precipitation sequence in Jiang Co recorded four periods of high precipitation: AD 80–500, 800–950, 1250–1450, and 1780–present, which is consistent with the long rainy season before AD 1000 but unclear afterward. Spatially, rainy season precipitation on the Plateau exhibited four patterns: “wet in both north and south” may be related to abnormally strong summer monsoons;“dry in both north and south” likely associated with weak Westerly wind and weak summer monsoon;“wet in the south and dry in the north” linked to strong summer monsoon and weak Westerly wind;and “dry in the south and wet in the north” connected to weak summer monsoon and strong Westerly wind. This study revealed the spatiotemporal evolution pattern of the rainy season onset and end, duration, and precipitation amount on the Plateau over the past two millennia. It provides natural background support for further understanding the coupling between Westerly wind and Asia

关键词： Tibetan Plateau Past two millennia Rainy season length Rainy season precipitation Quantitative reconstruction