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structural energy storage composites based on modified carbon fiber electrode with metal-organic frame enhancing layered double hydroxide

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Nano Research 2024年第3期17卷 1552-1563页

作者： Jinrui Ye Zhongbao Wang Qin lei lei sun Jinfeng Gu school of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China Tangshan Research Institute Beijing Institute of TechnologyTangshan 063000China school of Materials science and Engineering Shenyang Jianzhu UniversityShenyang 110168China Department of stomatology PLA Strategic Support Force Characteristic Medical CenterBeijing 100101China Beijing Electromechanical Engineering Research Institute Beijing 100074China

structural energy storage composites present advantages in simultaneously achieving structural strength and electrochemical *** of carbon fiber electrodes and resin structural electrolytes in energy storage composite poses challenges in maintaining good mechanical and electrochemical properties at reasonable cost and ***,we report a simple method to fabricate structural supercapacitor using carbon fiber electrodes(modified by Ni-layered double hydroxide(Ni-LDH)and in-situ growth of Co-metal-organic framework(Co-MOF)in a two-step process denoted as Co-MOF/Ni-LDH@CF)and bicontinuous-phase epoxy resin-based structural ***-MOF/Ni-LDH@CF as electrode material exhibits improved specific capacity(42.45 F·g^(-1))and cycle performance(93.3%capacity retention after 1000 cycles)in a three-electrode *** bicontinuous-phase epoxy resin-based structural electrolyte exhibits an ionic conductivity of 3.27×10^(-4) s·cm^(-1).The fabricated Co-MOF/Ni-LDH@CF/sPE-50 structural supercapacitor has an energy density of 3.21 Wh·kg^(-1) at a power density of 42.25 W·kg^(-1),whilst maintaining tensile strength and modulus of 334.6 MPa and 25.2 *** results show practical potential of employing modified commercial carbon fiber electrodes and epoxy resin-based structural electrolytes in structural energy storage applications.

关键词： carbon fiber electrode structural electrolyte structural energy storage composites supercapacitor

The Role of Underlying Boundary Forcing in shaping the Recent Decadal Change of Persistent Anomalous Activity over the Ural Mountains

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Advances in Atmospheric sciences 2024年第8期41卷 1496-1510,1661-1667页

作者： Ting lei shuanglin LI Climate Change Research Center Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Beijing Meteorological service Center Beijing 100089China University of Chinese Academy of sciences Beijing 100049China Department of Atmospheric science China University of GeosciencesWuhan 430074China

Observational analyses demonstrate that the Ural persistent positive height anomaly event(PAE) experienced a decadal increase around the year 2000, exhibiting a southward displacement afterward. These decadal variations are related to a large-scale circulation shift over the Eurasian Continent. The effects of underlying sea ice and sea surface temperature(ssT) anomalies on the Ural PAE and the related atmospheric circulation were explored by Atmospheric Model Intercomparison Project(AMIP) experiments from the Coupled Model Intercomparison Project Phase 6 and by sensitivity experiments using the Atmospheric General Circulation Model(AGCM). The AMIP experiment results suggest that the underlying sea ice and ssT anomalies play important roles. The individual contributions of sea ice loss in the Barents-Kara seas and the ssT anomalies linked to the phase transition of the Pacific Decadal Oscillation(PDO) and Atlantic Multidecadal Oscillation(AMO) are further investigated by AGCM sensitivity experiments isolating the respective *** sea ice decline in Barents-Kara seas triggers an atmospheric wave train over the Eurasian mid-to-high latitudes with positive anomalies over the Urals, favoring the occurrence of Ural PAEs. The shift in the PDO to its negative phase triggers a wave train propagating downstream from the North Pacific. One positive anomaly lobe of the wave train is located over the Ural Mountains and increases the PAE there. The negative-to-positive transition of the AMO phase since the late-1990s causes positive 500-h Pa height anomalies south of the Ural Mountains, which promote a southward shift of Ural PAE.

关键词： Ural persistent anomaly Pacific decadal oscillation Atlantic multidecadal oscillation sea ice loss in Barents-Kara seas

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Chien-physics-informed neural networks for solving singularly perturbed boundary-layer problems

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Applied Mathematics and Mechanics(English Edition) 2024年第9期45卷 1467-1480页

作者： Long WANG lei ZHANG Guowei HE The state Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of SciencesBeijing 100190China school of Engineering sciences University of Chinese Academy of SciencesBeijing 100049China

A physics-informed neural network(PINN)is a powerful tool for solving differential equations in solid and fluid ***,it suffers from singularly perturbed boundary-layer problems in which there exist sharp changes caused by a small perturbation parameter multiplying the highest-order *** this paper,we introduce Chien's composite expansion method into PINNs,and propose a novel architecture for the PINNs,namely,the Chien-PINN(C-PINN)*** novel PINN method is validated by singularly perturbed differential equations,and successfully solves the wellknown thin plate bending *** particular,no cumbersome matching conditions are needed for the C-PINN method,compared with the previous studies based on matched asymptotic expansions.

关键词： physics-informed neural network(PINN) singular perturbation boundarylayer problem composite asymptotic expansion

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Reducing social Media Attention Inequality in Disasters: The Role of Official Media During Rainstorm Disasters in China

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International Journal of Disaster Risk science 2024年第3期15卷 388-403页

作者： Longfei Zheng lei Chen Fenjie Long Jianing Liu lei Li school of Geography Faculty of Geographical Science Beijing Normal University Hang Lung Center for Real Estate and Department of Construction Management Tsinghua University

Unequal social media attention can lead to potentially uneven distribution of disaster-relief funds, resulting in long-term inequality among regions after disasters. This study aimed to measure inequalities in social media attention to regions during disasters and explore the role of official media in reducing such inequality. This is performed by employing social media,official media, and official aggregated statistics regarding China's rainstorm disasters. Through a set of panel-data regressions and robustness tests, three main conclusions were drawn:(1) There were inequalities among regions regarding social media attention they received during rainstorm disasters. For disasters of the same magnitude, regions with low economic outcome per capita received less attention on social media.(2) Official media can reduce inequality in social media attention during disasters. Official media statements can encourage netizens to pay attention to disaster-stricken areas, and especially the overlooked underdeveloped areas.(3) Of all the measures taken by official media, timely, accurate, and open disclosure of disaster occurrences proved to be the most potent means of leveling the playing field in terms of social media attention;contrarily, promotional or booster-type messages proved futile in this regard. These findings revealed the vulnerabilities within social media landscapes that aff ect disaster relief response, shedding light on the role of official guidance in mitigating inequalities in social media attention during such crises. Our study advises social media stakeholders and policymakers on formulating more equitable crisis communication strategies to bridge the gap in social media attention and foster a more balanced and just relief process.

关键词： China, inequality of attention Official media Rainstorm disasters situational crisis communication theory social media

Numerical analysis of a projecting wall type oscillating water column(PW-OWC)wave energy converter in regular waves

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Journal of Hydrodynamics 2024年第3期36卷 479-491页

作者： lei Tan Ruiyuan Chang Tomoki Ikoma Department of Oceanic Architecture and Engineering College of Science and TechnologyNihon UniversityChibaJapan

Oscillating water column(OWC)based wave energy absorption devices are classic which have been widely used for harnessing ocean wave *** paper presents a numerical study on a projecting wall(PW)type OWC wave energy converter in regular *** computational fluid dynamics(CFD)modelling of a stationary floating PW-OWC model in a three-dimensional wave flume is achieved by the software *** analyses are carried out based on CFD simulations and the linear potential flow solutions with modifications to account for turbine-induced *** present numerical solutions are validated against our previous experimental *** is found that both the CFD and modified linear potential flow predictions are in reasonably good agreements with the experimental data in the first order results of OWC and air pressure *** the nonlinear responses are included in the result,the modified linear potential flow solution is found to slightly under-estimate the wave energy conversion performance at long *** the airflows above and below the chamber orifice,the CFD results suggest that they are almost unidirectional,oscillating in not only the base frequency but also subharmonic and ultraharmonic *** evolution of the OWC responses during an entire period and the phase analysis based on CFD simulations are *** phase results provide the crucial evidence to the reasonability of the physics-based modification of the potential flow model in modelling of *** present results and analysis are expected to be beneficial to the understanding on the physical mechanism of OWCs and the design of phase control strategies.

关键词： Computational fluid dynamics(CFD)simulation hydrodynamic analysis oscillating water column(OWC)damping orifice airflow phase difference

Progress and prospect of Pt-based catalysts for electrocatalytic hydrogen oxidation reactions

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Nano Research 2024年第3期17卷 960-981页

作者： Xu Zhang Ying Xie lei Wang Key Laboratory of Functional Inorganic Material Chemistry Ministry of Education of the People’s Republic of ChinaHeilongjiang UniversityHarbin 150080China

To achieve the goals of the peak carbon dioxide emissions and carbon neutral,the development and utilization of sustainable clean energy are extremely *** fuel cells are an important system for converting hydrogen energy into electrical ***,the slow hydrogen oxidation reaction(HOR)kinetics under alkaline conditions has limited its ***,elucidating the catalytic mechanism of HOR in acidic and alkaline media is of great significance for the construction of highly active and stable *** terms of practicality,Pt is still the primary choice for commercialization of fuel *** the above basis,we first introduced the hydrogen binding energy theory and bifunctional theory used to describe the HOR activity,as well as the pH *** that,the rational design strategies of Pt-based HOR catalysts were systematically classified and summarized from the perspective of activity *** addition,we further emphasized the importance of theoretical simulations and in situ characterization in revealing the HOR mechanism,which is crucial for the rational design of ***,the practical application of Pt-based HOR catalysts in fuel cells was also *** closing,the current challenges and future development directions of HOR catalysts were *** review will provide a deep understanding for exploring the mechanism of highly efficient HOR catalysts and the development of fuel cells.

关键词： Pt-based catalysts hydrogen oxidation reaction(HOR) electrocatalytic mechanism hydrogen binding energy theory bifunctional theory

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

Cyclohexanol optimizes Pt/ionomer interface in fuel cell cathodes

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science China Chemistry 2024年第2期67卷 417-419页

作者： lei Tong Hai-Wei Liang Hefei National Research Center for Physical sciences at the Microscale Department of ChemistryUniversity of Science and Technology of ChinaHefei230026China

This highlight is based on a recent article published in Nature Catalysis, in which Wei's group [1] from Chongqing University proposes a novel approach to enhance the performance of proton exchange membrane fuel cells(PEMFCs)by adjusting the interface between Pt and ionomer in the cathode catalyst layer. Their strategy involves adding cyclohexanol to the cathode catalyst ink to impede the adsorption of sulfonate groups from the ionomer onto Pt nanoparticles, which results in the release of Pt activity sites and a significant improvement in the mass transport efficiency.

关键词： interface catalyst adding

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Dynamic motion of quadrupedal robots on challenging terrain:a kinodynamic optimization approach

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Frontiers of Mechanical Engineering 2024年第3期19卷 23-40页

作者： Qi LI lei DING Xin LUO Engineering Research Center of Hubei Province for Clothing Information Wuhan 430200China school of Computer science and Artificial Intelligence Wuhan Textile UniversityWuhan 430200China state Key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China

The dynamic motion of quadrupedal robots on challenging terrain generally requires elaborate spatial–temporal kinodynamic motion planning and accurate control at higher refresh rate in comparison with regular ***,conventional quadrupedal robots usually generate relatively coarse planning and employ motion replanning or reactive strategies to handle terrain *** resultant complex and computation-intensive controller may lead to nonoptimal motions or the breaking of locomotion *** this paper,a kinodynamic optimization approach is *** generate long-horizon optimal predictions of the kinematic and dynamic behavior of the quadruped robot on challenging terrain,we formulate motion planning as an optimization problem;jointly treat the foot’s locations,contact forces,and torso motions as decision variables;combine smooth motion and minimal energy consumption as the objective function;and explicitly represent feasible foothold region and friction constraints based on terrain *** track the generated motions accurately and stably,we employ a whole-body controller to compute reference position and velocity commands,which are fed forward to joint controllers of the robot’s *** verify the effectiveness of the developed approach through simulation and on a physical quadruped robot *** show that the quadruped robot can successfully traverse a 30°slope and 43% of nominal leg length high step while maintaining the rhythm of dynamic trot gait.

关键词： quadrupedal robot kinodynamic planning nonlinear optimization challenging terrain whole-body control