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Temperature-Dependent Tearing Behavior of Rubber Materials:Characterization and Modeling

Acta Mechanica Solida Sinica 2024年第2期37卷 316-326页

作者： Qinyuan yao Feilong Zhang Pan dong Ziyuan zhao Yi He Weiguo Li Liming Chen State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing UniversityChongqing400044China College of Aerospace Engineering Chongqing UniversityChongqing400044China

With the increasingly widespread application of rubber in many fields,there is a growing demand for quantitative characterization of temperature-dependent mechanical properties in high-temperature service *** critical tearing energy is an important criterion for determining whether rubber materials will experience tearing instability,while tear strength is a key parameter for rubber materials to resist *** is necessary to quantitatively characterize their evolution with *** theoretical research mainly relies on fitting a large amount of experimental data,which is not convenient for engineering ***,in this work,a temperature-dependent critical tearing energy model is firstly developed based on the force-heat equivalence energy density *** model considers the equivalent relationship between the critical tearing energy required for crack instability propagation and the thermal energy stored in the rubber *** is demonstrated that our model has higher prediction accuracy when compared to other ***,combining with the Griffith fracture theory,temperature-dependent tear strength models applicable to three different crack modes are separately *** models are validated using experimental data for Mode I opening cracks and ModeⅢtearing cracks,and good consistency is ***,a quantitative analysis of the influence of elastic modulus on tear strength at different temperatures is *** work provides a reliable way for predicting temperature-dependent tearing instability behavior and offers beneficial suggestions for improving the tear strength of rubber materials at different temperatures.

关键词： Temperature-dependent Critical tearing energy Tear strength Rubber Theoretical model

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Limits of Uneven Battery Power in Modular Multilevel Converter-based Battery Energy Storage Systems

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CSEE Journal of Power and Energy Systems 2024年第2期10卷 686-695页

作者： yao Pan Xiaofeng Sun Wei zhao Xin Li yao Cai Institute of Electrical Engineering Yanshan UniversityQinhuangdao 066004China

For modular multilevel converter-based battery energy storage systems (MMC-BESS), uneven power among batteries of SMs will be deduced by battery aging, battery fault, etc., which will degrade performance and even lead to system failure. For maintaining the balance of capacitor voltage, this paper analyzes the limits of the uneven power of batteries, which are presented as the current limits in this paper. According to analysis, an analytical method is proposed that only the dc and fundamental frequency components of the arm current are used to calculate current limits. With the current limits it is able to evaluate the reasonability of power distribution among batteries. Meanwhile, increase of fundamental frequency component will enhance the current limits, and the dc component determines the size relationship between the absolute values of the upper and lower current limits. Finally, simulation model and experiment prototype are built for verifying the theoretical analysis and current limits calculation method, and satisfactory results are provided.

关键词： Arm current balance of capacitor voltage current limits MMC-BESS uneven power

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Resilient control of flexible hypersonic vehicles against unmatched distributed faults

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Chinese Journal of Aeronautics 2024年第5期37卷 60-70页

作者： dong zhao Wenjing REN School of Artificial Intelligence Anhui UniversityHefei 230601China Key Laboratory of System Control and Information Processing Ministry of EducationShanghai Jiao Tong UniversityShanghai 200240China School of Electrical Engineering and Automation Hefei University of TechnologyHefei 230009China

This paper studies a robust fault compensation and vibration suppression problem of flexible hypersonic *** controlled plant is represented by a cascade system composed of a nonlinear Ordinary Differential Equation(ODE)and an Euler-Bernoulli Beam Equation(EBBE),in which the vibration dynamics is coupled with the rigid dynamics and suffers from distributed faults.A state differential transformation is introduced to transfer distributed faults to an EBBE boundary and a longitudinal dynamics is refined by utilizing T-S fuzzy IF-THEN rules.A novel T-S fuzzy based fault-tolerant control algorithm is developed and related stability conditions are *** robust exponential stability and well-posedness are proved by using the modified l_(0)-semigroup based Lyapunov direct approach.A simulation study on the longitudinal dynamics of flexible hypersonic vehicles effectively verifies the validity of the developed theoretical results.

关键词： Flexible hypersonic vehicles ODE-EBBE cascade Robust exponential stability Unmatched distributed fault compensation Vibration suppression

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First Description of Fossil Naucoridae (Heteroptera:Nepomorpha) from Late Mesozoic of China

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Acta Geologica Sinica(English Edition) 2011年第2期85卷 490-500页

作者： ZHANG Weiting yao Yunzhi REN dong zhao Yunyun College of Life Sciences Capital Normal University Beijing 100048 China

Herein the description and illustration of two new fossil genera and species of Naucoridae,Exilcrus cameriferus gen. ＆ sp. Nov. and Miroculus laticephlus gen. ＆ sp. Nov., are provided. Both species were collected from the Late Jurassic to Early Cretaceous Yixian Formation of western Liaoning, China. The complete preservation of the new specimens enable us to determine the characters of the specimens reported here. This finding represents the first record of fossil Naucoridae from China, which includes well-preserved nymphs. The possibility of a predatory habit of these specimens is discussed.

关键词： Naucoridae fossil Yixian Formation Upper Mesozoic China

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The clustering of QSOs and the dark matter halos that host them

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Research in Astronomy and Astrophysics 2013年第10期13卷 1141-1154页

作者： dong-yao zhao Chang-Shuo Yan Youjun Lu National Astronomical Observatories Chinese Academy of Sciences

The spatial clustering of QSOs is an important measurable quantity which can be used to infer the properties of dark matter halos that host *** construct a simple QSO model to explain the linear bias of QSOs measured by recent observations and explore the properties of dark matter halos that host a *** assume that major mergers of dark matter halos can lead to the triggering of QSO phenomena,and the evolution of luminosity for a QSO generally shows two accretion phases,i.e.,initially having a constant Eddington ratio due to the self-regulation of the accretion process when supply is sufcient,and then declining in rate with time as a power law due to either diminished supply or long term disk *** a Markov Chain Monte Carlo method,the model parameters are constrained by fitting the observationally determined QSO luminosity functions（LFs）in the hard X-ray and in the optical band *** the model parameters that best fit the QSO LFs,the linear bias of QSOs can be predicted and then compared with the observational measurements by accounting for various selection efects in diferent QSO *** find that the latest measurements of the linear bias of QSOs from both the SDSS and BOSS QSO surveys can be well *** typical mass of SDSS QSOs at redshift 1.5

关键词： black hole physics galaxies:active cosmology

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Thylakoid engineered M2 macrophage for sonodynamic effect promoted cell therapy of early atherosclerosis

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Nano Research 2024年第4期17卷 2919-2928页

作者： Guanghao Wu Changwen Mu Qianru zhao yao Lei Ran Cheng Weidong Nie Jiamin Qu Yuping dong Ruili Yang Haiyan Xie State Key Laboratory of Natural and Biomimetic Drugs School of Pharmaceutical SciencesChemical Biology CenterPeking UniversityBeijing 100191China School of Materials Science and Engineering Beijing Institute of TechnologyBeijing 100081China School of Life Science Beijing Institute of TechnologyBeijing 100081China School of Stomatology Peking UniversityBeijing 100081China

Atherosclerosis is the most common cause of cardiovascular diseases that contribute to the major morbidity worldwide,but still lacking of effective treatment ***,a hybrid cell is constructed for the sonodynamic effect promoted cell therapy of early atherosclerosis by fusing M2 macrophages with thylakoid(TK)*** systemic administration,the obtained TK-M2 actively accumulates in the early atherosclerotic plaques,wherein M2 macrophages relieve the cholesterol accumulation and the inflammation in the foam ***,the TK membranes decorated on the M2 macrophages exhibit both type I and type II sonodynamic effects under ultrasound(US)activation,inducing the direct apoptosis of foam *** cooperation of M2 and TK leads to significant outcome in eliminating atherosclerotic plaques without obvious side-effects,providing a new avenue for atherosclerosis treatment.

关键词： atherosclerosis thylakoid ultrasound M2 macrophage

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Event-Triggered Bipartite Consensus Tracking and Vibration Control of Flexible Timoshenko Manipulators Under Time-Varying Actuator Faults

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IEEE/CAA Journal of Automatica Sinica 2024年第5期11卷 1190-1201页

作者： Xiangqian yao Hao Sun Zhijia zhao Yu Liu School of Automation Science and Engineering South China University of TechnologyGuangzhou 510640China Yongjiang Laboratory Ningbo 315202 School of Astronautics Harbin Institute of TechnologyHarbin 150001China School of Mechanical and Electrical Engineering Guangzhou UniversityGuangzhou 510006China

For bipartite angle consensus tracking and vibration suppression of multiple Timoshenko manipulator systems with time-varying actuator faults,parameter and modeling uncertainties,and unknown disturbances,a novel distributed boundary event-triggered control strategy is proposed in this *** contrast to the earlier findings,time-varying consensus tracking and actuator defects are taken into account *** addition,the constructed event-triggered control mechanism can achieve a more flexible design because it is not required to satisfy the input-to-state *** achieve the control objectives,some new integral control variables are given by using back-stepping technique and boundary ***,adaptive neural networks are applied to estimate system *** the proposed event-triggered scheme,control inputs can reduce unnecessary ***,tracking errors and vibration states of the closed-looped network can be exponentially convergent into some small fields,and Zeno behaviors can be *** last,some simulation examples are given to state the effectiveness of the control algorithms.

关键词： Vibration satisfy bipartite

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Edge dislocation-induced strains break the limit of PtNi alloys in boosting Pt mass activity for efficient alkaline hydrogen evolution

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Nano Research 2024年第6期17卷 4711-4719页

作者： Miao Zhou yao zhao Zhanwei Liu Xueru zhao Enzuo Liu Liyang Xiao Pengfei Yin Cunku dong Hui Liu Xiwen Du Jing Yang New Energy Materials Institute School of Materials Science and EngineeringTianjin UniversityTianjin 300072China School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China Chemistry Division Brookhaven National LaboratoryUptonNew York 11973USA Advanced Metallic Materials Institute School of Materials Science and EngineeringTianjin UniversityTianjin 300072China

Creating lattice defects and alloying to produce strain effect in Pt-based bimetallic alloys are both effective methods to optimize the crystal and electronic structure and improve the electrocatalytic ***,the principles that govern the alkaline hydrogen evolution reaction(HER)performance remain unclear,which is detrimental to the rational design of efficient Pt-based ***,PtNi alloys with different Pt/Ni ratios and edge dislocations were synthesized,and the effects of Pt/Ni composition and edge dislocations on the alkaline HER electrocatalytic activity of PtNi alloys were systematically *** experimental and theoretical investigations reveal that tuning Pt/Ni ratio results in only 1.1 times enhancements in Pt mass activity,whereas edge dislocations-induced extra tensile strain on Ni site and compressive strain on Pt site further boost the alkaline HER intrinsic activity at all Pt/Ni ***,the introduction of edge dislocations in PtNi alloys could break the limit of alloying in boosting Pt mass activity and result in up to 13.7-fold enhancement,in the case that Pt and Ni contents are nearly identical and thus edge dislocation density reaches the *** mechanism studies demonstrate that the edge dislocation strategy could make a breakthrough in facilitating water dissociation kinetics of PtNi alloys.

关键词： edge dislocations PtNi composition strain effects water dissociation hydrogen evolution reaction

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ZP2:the precision regulator of egg coat architecture during fertilization

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Science China(Life Sciences) 2024年第8期67卷 1779-1780页

作者： Yi dong Shigang zhao Han zhao State Key Laboratory of Reproductive Medicine and Offspring Health Center for Reproductive MedicineInstitute of WomenChildren and Reproductive HealthShandong UniversityJinan 250012China

In a recent study published in Cell,(Nishio et al.,2024)elucidated the molecular regulatory mechanism through which organisms prevent *** process intricately involves conformational changes in the zona pellucida(ZP)*** authors present a fascinating mechanism whereby post-fertilization cleavage of the ZP subunit ZP2 triggers its oligomerization,leading to crosslinking of filaments to harden the egg coat and prevent *** also systematically analyzed the pattern of ZP filament assembly,which revealed that two protofilaments comprising type I(ZP3)and type II(ZP1/ZP2/ZP4)components interlock to form a left-handed double helix *** findings are immensely beneficial for understanding the specific role of the egg coat,providing a plethora of insights.

关键词： mechanism finding crosslinking

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Degradation of warm permafrost and talik formation on the Qinghai-Tibet Plateau in 2006-2021

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Advances in Climate Change Research 2024年第2期15卷 275-284页

作者： Qi-Hang MEI Ji CHEN You-Qian LIU Shou-Hong ZHANG Jing-Yi zhao Tian-Chun dong Jun-Cheng WANG yao-Jun zhao Beiluhe Observation and Research Station of Frozen Soil Engineering and Environment Key Laboratory of Cryospheric Science and Frozen Soil EngineeringNorthwest Institute of Eco-Environmental and ResourcesChinese Academy of SciencesLanzhou 730000China China Railway Qinghai-Tibet Group Co.Ltd Xining 810007China University of Chinese Academy of Sciences Beijing 100049China

Permafrost is degrading globally,particularly those with low thermal stability on the Qinghai-Tibet Plateau,owing to climate ***,the inadequacy of direct research on permafrost degradation based on in-situ monitoring limits the prediction of permafrost degradation and engineering *** study explored the processes and modes of permafrost degradation into talik by analyzing ground temperature data from five points in the hinterland of the Qinghai-Tibet Plateau from 2006 to *** results showed that the degradation of the warm permafrost layer with a geothermal gradient of zero occurred simultaneously in the top and bottom *** rate of permafrost degradation from the top down and bottom up increase during the degradation process,but the increase of the former is more drastic after the formation of thawed ***,the construction of the Qinghai-Tibet Railway changed the degradation modes of the permafrost in adjacent natural sites through horizontal heat transfer,particularly after through talik formation under the *** findings suggest that taking countermeasures before or immediately after forming thawed interlayer is more *** evaluating the thermal impact of projects in warm permafrost regions,special attention should be given to the horizontal heat transfer process that may result from the formation of a through talik.

关键词： Warm permafrost Degradation Talik Qinghai-Tibet Plateau Climate change

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