检索结果-南通市图书馆

Amorphous hybrid tungsten oxide–nickel hydroxide nanosheets used as a highly efficient electrocatalyst for hydrogen evolution reaction

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2024年第4期17卷 2499-2508页

作者： Chao Lyu Chenghai Dai Yiwei Tan State Key laboratory of Materials-Oriented Chemical engineering School of Chemistry and Chemical EngineeringNanjing Tech UniversityNanjing 211816China

There are more challenges for alkaline hydrogen evolution reaction(HER)via simultaneously expediting the electron-coupled water dissociation process(Volmer step)and the following electrochemical H_(2) desorption(Heyrovsky step).Hybrid amorphous electrocatalysts are highly desirable for efficient hydrogen evolution from water-alkali electrolyzers due to the bifunctionality for the different elementary steps of HER and optimal interactions with water molecules and the reactive hydrogen intermediates(Had).Herein,the synthesis of amorphous hybrid ultrathin(tungsten oxide/nickel hydroxide)hydrate(a-[WO_(3)/Ni(OH)_(2)]·0.2H_(2)O)nanosheets on nickel foam(NF)for efficient alkaline HER is described.The structural and composition features of a-[WO_(3)/Ni(OH)_(2)]·0.2H_(2)O are characterized in detailed.The resulting a-[WO_(3)/Ni(OH)_(2)]·0.2H_(2)O/NF electrocatalyst with the synergistic effect of both hybrid components for the HER elementary steps shows greatly improved the activity and durability for the HER with a low overpotential of-41 and-163 mV at-10 and-500 mA·cm^(-2),respectively,a Tafel slope as low as-72.9 mV·dec^(-1),and long-term stability of continuous electrolysis for at least 150 h accompanying by inappreciable overpotential change in 1 M KOH.In the hybrid a-[WO_(3)/Ni(OH)_(2)]·0.2H_(2)O,Ni(OH)_(2) and WO_(3) moieties are separately responsible for accelerating dissociative adsorption of water and weakening Had adsorption strength,which is beneficial to the improvement of the alkaline HER activity.

关键词： amorphous nanomaterial bimetallic electrocatalyst tungsten oxide ultrathin nanosheet hydrogen evolution reaction

Numerical Study on the Aerodynamic and Fluid−Structure Interaction of An NREL-5MW Wind Turbine

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

China Ocean engineering 2024年第3期38卷 363-378页

作者： ZHAO Mi YU Wan-li WANG Pi-guang QU Yang DU Xiu-li Key laboratory of Urban Security and Disaster engineering of Ministry of Education Beijing University of TechnologyBeijing 100124China State Key laboratory of Bridge engineering Safety and Resilience Beijing University of TechnologyBeijing 100124China

A 5-MW wind turbine has been modeled and analyzed for fluid-structure interaction and aerodynamic performance.In this study,a full-scale model of a 5-MW wind turbine is first developed based on a computational fluid dynamics(CFD)approach,in which the unsteady,noncompressible Reynolds Averaged Navier‒Stokes(RANS)method is used.The main focus of the study is to analyze the tower shadow effect on the aerodynamic performance of the wind turbine under different inlet flow conditions.Subsequently,the finite element model is established by considering fluid/structure interactions to study the structural stress,displacement,strain distributions and flow field information of the structure under the uniform wind speed.Finally,the fluid-structure interaction model is established by considering turbulent wind and the tower shadow effect.The variation rules of the dynamic response of the one-way and twoway fluid−structure interaction(FSI)models under different wind speeds are analyzed,and the numerical calculation results are compared with those of the centralized mass model.The results show that the tower shadow effect and structural deformation are the main factors affecting the aerodynamic load fluctuation of the wind turbine,which in turn affects the aerodynamic performance and structural stability of the blades.The structural dynamic response of the coupled model shows significant similarity,while the structural displacement response of the former exhibits less fluctuation compared with the conventional centralized mass model.The one-way fluid-structure interaction(FSI)model shows a higher frequency of stress-strain and displacement oscillations on the blade compared with the twoway FSI model.

关键词： computational fluid dynamics methods(CFD) tower shadow effect aerodynamic performance fluidstructure interaction space flow field

Understanding the correlation between energy-state mismatching and open-circuit voltage loss in bulk heterojunction solar cells

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Carbon Energy 2024年第5期6卷 164-174页

作者： Hyun-Seock Yang Danbi Kim Chang-Mok Oh Vellaiappillai Tamilavan Pesi MHangoma Hojun Yi Bo RLee Insoo Shin In-Wook Hwang Sung Heum Park Pukyong National University BusanRepublic of Korea Clarendon laboratory University of OxfordOxfordUK Institute of Energy Transport and Fusion Research Pukyong National UniversityBusanRepublic of Korea Advanced Photonics Research Institute Gwangju Institute of Science and TechnologyGwangjuRepublic of Korea Department of Chemical and biomolecular engineering Tandon School of EngineeringNew York UniversityBrooklynNew YorkUSA

Photoinduced intermolecular charge transfer(PICT)determines the voltage loss in bulk heterojunction(BHJ)organic photovoltaics(OPVs),and this voltage loss can be minimized by inducing efficient PICT,which requires energy-state matching between the donor and acceptor at the BHJ interfaces.Thus,both geometrically and energetically accessible delocalized state matching at the hot energy level is crucial for achieving efficient PICT.In this study,an effective method for quantifying the hot state matching of OPVs was developed.The degree of energy-state matching between the electron donor and acceptor at BHJ interfaces was quantified using a mismatching factor(MF)calculated from the modified optical density of the BHJ.Furthermore,the correlation between the open-circuit voltage(Voc)of the OPV device and energy-state matching at the BHJ interface was investigated using the calculated MF.The OPVs with small absolute MF values exhibited high Voc values.This result clearly indicates that the energy-state matching between the donor and acceptor is crucial for achieving a high Voc in OPVs.Because the MF indicates the degree of energy-state matching,which is a critical factor for suppressing energy loss,it can be used to estimate the Voc loss in OPVs.

关键词： bulk heterojunction open circuit voltage organic photovoltaics photoinduced charge transfer voltage loss

Study of deep transportation and plugging performance of deformable gel particles in porous media

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Petroleum Science 2024年第2期21卷 962-973页

作者： Wen-Jing Zhao Jing Wang Zhong-Yang Qi Hui-Qing Liu National Key laboratory of Petroleum Resources and engineering China University of PetroleumBeijing102249China MOE Key laboratory of Petroleum engineering China University of PetroleumBeijing102249China

Deformable gel particles(DGPs) possess the capability of deep profile control and flooding. However, the deep migration behavior and plugging mechanism along their path remain unclear. Breakage, an inevitable phenomenon during particle migration, significantly impacts the deep plugging effect. Due to the complexity of the process, few studies have been conducted on this subject. In this paper, we conducted DGP flow experiments using a physical model of a multi-point sandpack under various injection rates and particle sizes. Particle size and concentration tests were performed at each measurement point to investigate the transportation behavior of particles in the deep part of the reservoir. The residual resistance coefficient and concentration changes along the porous media were combined to analyze the plugging performance of DGPs. Furthermore, the particle breakage along their path was revealed by analyzing the changes in particle size along the way. A mathematical model of breakage and concentration changes along the path was established. The results showed that the passage after breakage is a significant migration behavior of particles in porous media. The particles were reduced to less than half of their initial size at the front of the porous media. Breakage is an essential reason for the continuous decreases in particle concentration, size, and residual resistance coefficient. However, the particles can remain in porous media after breakage and play a significant role in deep plugging. Higher injection rates or larger particle sizes resulted in faster breakage along the injection direction, higher degrees of breakage, and faster decreases in residual resistance coefficient along the path. These conditions also led to a weaker deep plugging ability. Smaller particles were more evenly retained along the path, but more particles flowed out of the porous media, resulting in a poor deep plugging effect. The particle size is a function of particle size before injection, transport distance, and different injection

关键词： Physical simulation Deformable gel particle Breakage Particle size Residual resistance coefficient

Laser-upgraded coal tar for smart pavements in road and bridge monitoring applications

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Microsystems & Nanoengineering 2024年第2期10卷 231-239页

作者： Jincai Huang Man Zhang Haoyun He Qingang Li Yixin Zhao Qiulin Tan Xining Zang Department of Mechanical engineering Tsinghua UniversityBeijing100084China State Key laboratory of Clean and Efficient Turbomachinery Power Equipment Department of Mechanical EngineeringTsinghua UniversityBeijing100084China Key laboratory for Advanced Materials Processing Technology Ministry of EducationBeijing100084China Science and Technology on Electronic Test and Measurement laboratory North University of ChinaTaiyuan030051China School of Energy and Mining engineering China University of Mining and Technology(Beijing)Beijing100083China

The implementation of an intelligent road network system requires many sensors for acquiring data from roads,bridges,and vehicles,thereby enabling comprehensive monitoring and regulation of road networks.Given this large number of required sensors,the sensors must be cost-effective,dependable,and environmentally friendly.Here,we show a laser upgrading strategy for coal tar,a low-value byproduct of coal distillation,to manufacture flexible strain-gauge sensors with maximum gauge factors of 15.20 and 254.17 for tension and compression respectively.Furthermore,we completely designed the supporting processes of sensor placement,data acquisition,processing,wireless communication,and information decoding to demonstrate the application of our sensors in traffic and bridge vibration monitoring.Our novel strategy of using lasers to upgrade coal tar for use as a sensor not only achieves the goal of turning waste into a resource but also provides an approach to satisfy large-scale application requirements for enabling intelligent road networks.

关键词： gauge bridge smart

Hydrogen spillover bridged dual nano-islands triggered by built-in electric field for efficient and robust alkaline hydrogen evolution at ampere-level current density

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2024年第6期17卷 5050-5060页

作者： Kecheng Tong Liangliang Xu Hanxu Yao Xingkun Wang Canhui Zhang Fan Yang Lei Chu Jinwoo Lee Heqing Jiang Minghua Huang School of Materials Science and engineering Ocean University of ChinaQingdao 266100China Department of Chemical and biomolecular engineering Korea Advanced Institute of Science and Technology(KAIST)291Daejeon 34141Republic of Korea Qingdao New Energy Shandong laboratory Qingdao Institute of Bioenergy and Bioprocess TechnologyChinese Academy of SciencesQingdao 266101China University of Chinese Academy of Sciences Beijing 100049China

Employing the alkaline water electrolysis system to generate hydrogen holds great prospects but still poses significant challenges,particularly for the construction of hydrogen evolution reaction(HER)catalysts operating at ampere-level current density.Herein,the unique Ru and RuP_(2)dual nano-islands are deliberately implanted on N-doped carbon substrate(denoted as Ru-RuP_(2)/NC),in which a built-in electric field(BEF)is spontaneously generated between Ru-RuP_(2)dual nano-islands driven by their work function difference.Experimental and theoretical results unveil that such constructed BEF could serve as the driving force for triggering fast hydrogen spillover process on bridged Ru-RuP_(2)dual nano-islands,which could invalidate the inhibitory effect of high hydrogen coverage at ampere-level current density,and synchronously speed up the water dissociation on Ru nano-islands and hydrogen adsorption/desorption on RuP_(2)nano-islands through hydrogen spillover process.As a result,the Ru-RuP_(2)/NC affords an ultra-low overpotential of 218 mV to achieve 1.0 A·cm^(−2)along with the superior stability over 1000 h,holding the great promising prospect in practical applications at ampere-level current density.More importantly,this work is the first to advance the scientific understanding of the relationship between the constructed BEF and hydrogen spillover process,which could be enlightening for the rational design of the cost-effective alkaline HER catalysts at ampere-level current density.

关键词： built-in electric field hydrogen spillover dual nano-islands ampere-level current density alkaline hydrogen evolution

Promising thermal photonic management materials for sustainable human habitat

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2024年第1期17卷 112-131页

作者： Houze Yao Qihua Liao Huhu Cheng Liangti Qu Key laboratory of Organic Optoelectronics&Molecular engineering Ministry of EducationDepartment of ChemistryLaboratory of Flexible Electronics TechnologyTsinghua UniversityBeijing 100084China State Key laboratory of Tribology in Advanced Equipment(SKLT) Department of Mechanical EngineeringTsinghua UniversityBeijing 100084China

The spectral characteristics of outdoor structures,such as automobiles,buildings,and clothing,determine their energy interaction with the environment,from broad-spectrum absorption of light energy to high-efficiency thermal emission.Recently developed spectrally selective absorption(SSA)materials permit the reduction of energy loss from human habitat eco-system in the sustainable way and further reduce the utilization of fossil energy to achieve carbon neutrality.Here we review recent advances in SSA materials that enable rational and efficient management of thermal energy and provide new solutions for the resource base that supports human life like comfortable heat management,electricity production,and water supply.The basic principles of thermal photonic management,the regulation of SSA materials,and functional properties are summarized.An outlook discussing challenges and opportunities in SSA material energy management for comfortable living environments is finally presented,which expects the enormous potential of this interdisciplinary research in solving growing resource-shortage of human society.

关键词： spectrally selective absorption passive cooling solar power eco-system

Persistent radical anion of perylene dianhydride:an emerging metal-free photocatalyst for near-infrared photocontrolled RAFT polymerization

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第2期67卷 677-686页

作者： Haitao Zhao Guoqing Bian Xiang Xu Weiwei He Lifen Zhang Zhenping Cheng State and Local Joint engineering laboratory for Novel Functional Polymeric Materials Jiangsu Key Laboratory of Advanced Functional Polymer Design and ApplicationSuzhou Key Laboratory of Macromolecular Design and Precision SynthesisCollege of ChemistryChemical Engineering and Materials ScienceSoochow UniversitySuzhou215123China

Developing a new type of photocatalyst(PC) and catalytic mechanism for near-infrared(NIR) photocontrolled reversibledeactivation radical polymerization(RDRP) system is charming but challenging.Herein,a novel PC of the persistent radical anion(PRA)(possessing the properties of both radical and anion) was developed for NIR photocontrolled reversible additionfragmentation chain transfer(RAFT) polymerization,enabling successful polymerization while gaining a deep insight into the mechanism of photo-induced electron transfer RAFT(PET-RAFT) polymerization.Different from the conventional and wellaccepted reductive quenching(RQ) pathway,in which the radical anion intermediates of PCs(PCs^(·-)) must be generated in an excited state(ES),here,the PRA(3,4,9,10-perylenetetracarboxylic dianhydride radical anion(PTCDA^(·-))) could generate conveniently in situ in the ground state(GS) and subsequently serve as highly efficient PC in the NIR region(740–850 nm).The successful implementation of this strategy elucidates the peculiar role played by light and the real way of electron transfer behaviors.In fact,the transfer of a single electron from PRA to chain transfer agent(CTA) and cleavage of the C–S bonds is a process from ES to GS,rather than always from GS(PCs^(·-)) to GS(CTA) in the RQ pathway as is well known to all.In addition,the excellent spatial-temporal control and powerful penetration ability of the NIR light were also confirmed by this PRAcatalyzed polymerization system.

关键词： photocatalyst persistent radical anion(PRA) near-infrared(NIR)light reversible-deactivation radical polymerization(RDRP) photo-induced electron transfer RAFT(PET-RAFT)polymerization

Experimental study on the influences of cutter geometry and material on scraper wear during shield TBM tunnelling in abrasive sandy ground

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical engineering 2024年第2期16卷 410-425页

作者： Shaohui Tang Xiaoping Zhang Quansheng Liu Qi Zhang Xinfang Li Haojie Wang Key laboratory of Safety for Geotechnical and Structural engineering of Hubei Province School of Civil EngineeringWuhan UniversityWuhan430072China State Key laboratory of Water Resources and Hydropower engineering Science Wuhan UniversityWuhan430072China

When shield TBM tunnelling in abrasive sandy ground,the rational design of cutter parameters is critical to reduce tool wear and improve tunnelling efficiency.However,the influence mechanism of cutter parameters on scraper wear remains unclear due to the lack of a reliable test method.Geometry and material optimisation are often based on subjective experience,which is unfavourable for improving scraper geological adaptability.In the present study,the newly developed WHU-SAT soil abrasion test was used to evaluate the variation in scraper wear with cutter geometry,material and hardness.The influence mechanism of cutter parameters on scraper wear has been revealed according to the scratch characteristics of the scraper surface.Cutter geometry and material parameters have been optimised to reduce scraper wear.The results indicate that the variation in scraper wear with cutter geometry is related to the cutting resistance,frictional resistance and stress distribution.An appropriate increase in the front angle(or back angle)reduces the cutting resistance(or frictional resistance),while an excessive increase in the front angle(or back angle)reduces the edge angle and causes stress concentration.The optimal front angle,back angle and edge angle for quartz sand samples areα=25°,β=10°andγ=55°,respectively.The wear resistance of the modelled scrapers made of different metal materials is related to the chemical elements and microstructure.The wear resistances of the modelled scrapers made of 45#,06Cr19Ni10,42CrMo4 and 40CrNiMoA are 0.569,0.661,0.691 and 0.728 times those made of WC-Co,respectively.When the alloy hardness is less than 47 HRC(or greater than 58 HRC),scraper wear decreases slowly with increasing alloy hardness as the scratch depth of the particle asperity on the metal surface stabilizes at a high(or low)level.However,when the alloy hardness is between 47 HRC and 58 HRC,scraper wear decreases rapidly with increasing alloy hardness as the scratch depth transitions from high to low levels.The sensitive hardness i

关键词： Shield TBM Scraper wear Cutter shape Metal material Alloy hardness