检索结果-南通市图书馆

Journal of Rare Earths 2024年第1期42卷 46-56,I0002页

作者： L.Vijayalakshmi K.Naveen Kumar Jong Dae Baek department of Automotive engineering Yeungnam UniversityGyeongsanGyeongbuk38541Republic of Korea department of mechanical engineering Yeungnam UniversityGyeongsan38541Republic of Korea

A set of co-doped(Tb^(3+)/Dy^(3+))lithium zinc borate(LZB)glasses were developed by melt *** structural evaluation was performed for synthesized glassy *** Dy^(3+)and Tb^(3+)individually doped glasses exhibit intense yellow and green luminescence bands at 575 nm(^(4)F_(9/2)→^(6)H_(13/2))and543 nm(^(5)D_(4)→^(7)F_(5)),*** sensitization effect of Dy^(3+)on Tb^(3+)was analyzed by increasing the Tb^(3+)content with respect to the optimum Dy^(3+)content(0.5 mol%)in Dy^(3+)/Tb^(3+).The spectral overlay of Dy^(3+)luminescence and Tb^(3+)absorption profiles,Dy^(3+)/Tb^(3+)PL spectra under different excitations 352,362,376,and 385 nm,shortening decay lifetimes of Dy^(3+)in Dy^(3+)/Tb^(3+)co-activated glasses,energy transfer(ET)parameters,chromaticity coordinates and their corresponding correlated temperatures all help to explain ET from Dy^(3+)to Tb^(3+).At 385 nm of Dy^(3+)excitation,the optimized co-activated(0.5Dy^(3+)+1.0Tb^(3+)):LZB glass displays cool white light *** non-radiative ET from Dy^(3+)to Tb^(3+)is dominated by electric dipole-dipole interaction and its ET efficiency was calculated to be 63%.At the same time,reverse ET from Tb^(3+)to Dy^(3+)was also *** shift in color coordinates from dominant yellow to greenish-yellow,green and white light emission suggests that Dy^(3+)/Tb^(3+)coactivated LZB glasses can be a potential candidate for UV converted multicolor and white light emitting devices.

关键词： Rare earths Photoluminescence Energy transfer Spectral overlap Decay lifetime Multicolor emitting LEDs

Tribological behavior of TiN,AlTiN,and AlTiCrN coatings in atmospheric and vacuum environments

在线全文

学校读者我要写书评

暂无评论

Friction 2024年第11期12卷 2611-2626页

作者： Youn-Hoo HWANG Kuk-Jin SEO Tae-Hyeong KIM You Jin MIN Yuzhen LIU Dae-Eun KIM department of mechanical engineering Yonsei UniversitySeoul 03722Republic of Korea department of Mechatronics and Energy engineering Ningbo Tech UniversityNingbo 315211China

In this study,the tribological characteristics of TiN,AlTiN,and AlTiCrN coatings sliding against a SUS420J1 stainless steel pin were investigated in atmospheric and vacuum *** coatings were deposited on SUS440C substrates using the arc-physical vapor deposition *** friction and wear behavior of the coatings were evaluated based on the systematic analyses of the friction coefficient data as well as the physical and chemical state of the wear *** results revealed that the friction coefficients of the SUS440C specimen and AlTiCrN coatings increased,whereas those of the TiN and AlTiN coatings decreased when the environment was changed from atmospheric to *** was confirmed that the formation of an oxide layer and adsorption of oxides on the surface were dominant factors that influenced the tribological behavior in the atmospheric *** the other hand,the compatibility,oxidation inhibition,and droplets of the surface mainly affected the frictional characteristics in the vacuum *** results of this work are expected to aid in the selection of proper coating materials for tribological systems operating in a vacuum.

关键词： friction wear coating vacuum TiN

Bilayer separator enabling dendrite-free zinc anode with ultralong lifespan >5000 h

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Green Energy & Environment 2024年第4期9卷 771-776页

作者： Lu Wang Feifei Wang Zhe Ding Yingxin Liu Ziyi Zhang Chunpeng Yang Kian Ping Loh Quan-Hong Yang Joint School of national university of singapore and Tianjin university International Campus of Tianjin UniversityFuzhou350207China Nanoyang Group State Key Laboratory of Chemical EngineeringSchool of Chemical Engineering and TechnologyTianjin UniversityCollaborative Innovation Center of Chemical Science and Engineering(Tianjin)Tianjin300072China Haihe Laboratory of Sustainable Chemical Transformations Tianjin300192China department of Chemistry National University of Singapore117543Singapore Institute of Process engineering Chinese Academy of SciencesBeijing100190China

Aqueous zinc(Zn)batteries with Zn metal anodes are promising clean energy storage devices with intrinsic safety and low ***,Zn dendrite growth severely restricts the use of Zn *** effectively suppress Zn dendrite growth,we propose a bilayer separator consisting of commercial butter paper and glassfiber *** dense cellulose-based butter paper(BP)with low zincophilicity and high mechanical properties prevents the pore-filling behavior of deposited Zn and related separator piercing,effectively suppressing the Zn dendrite *** a result,the bilayer separators endow the ZnjjZn symmetrical batteries with a superlong cycling life of Zn anodes(over 5000 h)at 0.5 mA cm^(-2) and the full batteries enhanced capacity retention,demonstrating the advancement of the bilayer separator to afford excellent cyclability of aqueous metal batteries.

关键词： Zn battery Bilayer separator Butter paper Zn metal anode Zn dendrite

Rapid surface texturing to achieve robust superhydrophobicity,controllable droplet impact,and anti-frosting performances

在线全文

学校读者我要写书评

暂无评论

Friction 2024年第2期12卷 291-304页

作者： Qingwen DAI Lei CHEN Jiabao PAN Liping SHI Dameng LIU Wei HUANG Xiaolei WANG College of mechanical and Electrical engineering Nanjing University of Aeronautics&AstronauticsNanjing 210016China State Key Laboratory of Tribology in Advanced Equipment Department of Mechanical EngineeringTsinghua UniversityBeijing 100084China School of mechanical engineering Anhui Polytechnic UniversityWuhu 241000China School of mechanical engineering Anhui University of TechnologyMa’anshan 243032China

Robust superhydrophobic surfaces with excellent capacities of repelling water and anti-frosting are of importance for many mechanical *** this work,wear-resistant superhydrophobic surfaces were fabricated by curing a mixture of polyurethane acrylate(PUA)coating and 1H,1H,2H,2H-Perfluorodecyltrichlorosilane(HFTCS)on titanium alloy(TC4)surfaces decorated with micropillars pattern,thus,composite functional surfaces with PUA coating in the valleys around the micropillars pattern of TC4 were *** contact angle on fabricated surfaces could reach 167°.Influences of the geometric parameters of micropillars pattern on the apparent contact angle were investigated,and the corresponding wear-resistant property was *** impact and anti-frosting performances on the prepared surfaces were *** optimized design of surface texture with robust superhydrophobicity,controllable droplet impact,and anti-frosting performances was *** design principle is of promising prospects for fabricating superhydrophobic surfaces in traditional mechanical systems.

关键词： surface texture robust superhydrophobic wear-resistant droplet impact anti-frosting

Metal-Organic Frameworks Housing Active Molecules as Bioinspired Catalysts

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

CCS Chemistry 2024年第6期6卷 1380-1402页

作者： Yin Zhang Peter E.VanNatta Junyu Ren Shengqian Ma department of Chemistry University of North TexasDentonTexas 76201 department of Chemical and Biomolecular engineering National University of SingaporeSingapore 117585

Optimization of activity,selectivity,and stability of catalysts for practical application is a long-soughtafter *** progress in the advancement of rational catalyst design routinely takes queues from ***,enzymes are renowned for their high efficiency and selectivity in diverse and significant reactions under mild *** the well-known merits of enzymes,they often remain unsuitable for industrial catalysis due to issues,including limited environment(solvent/temperature/pH)compatibility,considerable structural uncertainty,and highly specific reaction *** the context of bioinspired catalysis design,the development of synthetic heterogeneous catalyst analogs,which may not only mimic enzymes to reproduce or even surpass their performance but also bypass their intrinsic limitations,is thus,desirable and has been extensively studied in the context of porous *** metal-organic framework(MOF)is a superior candidate for porous materials towards this goal,thanks to facile and modular preparation,explicit crystalline composition/structure,tunable pore size/environment,and excellent *** introduction of active molecular species such as bioactive molecules(e.g.,proteins,enzymes,peptides,amino acids,porphyrins)and chemically active molecules(e.g.,frustrated Lewis pairs)into metal-organic frameworks(MOFs)via pore encapsulation,chemical postmodification,or bottom-up construction has been shown to facilitate the cooperative enhancement of catalysis through the enforcement of proximity,enhancement of control/activity,and even inducement of unexpected *** this minireview,we sought to summarize the last 5 years of fruitful progress,exploiting MOFs housing active molecules for substantial catalysis applications,including asymmetric reactions,CO_(2)conversion(reduction,cycloaddition),biocatalytic H_(2)O_(2)/dye degradation,and so on,and discuss challenges and opportunities in the prospective exploration of these system

关键词： metal-organic framework bioinspired catalyst active molecular species

Transmissive reconfigurable metasurface enabling independent control of active and passive modules through weak coupling

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Photonics Research 2024年第7期12卷 1449-1456页

作者： KUN XUE HENG WEI CILEI ZHANG YONGHAO ZHANG HAOLIANG SUN SHAOHUA DONG Peng Cheng Laboratory Shenzhen 518055China department of Electrical and Computer engineering National University of SingaporeSingapore 117583Singapore State Key Laboratory of Radio Frequency Heterogeneous Integration College of Electronics and Information EngineeringShenzhen UniversityShenzhen 518060China

Metasurfaces have demonstrated rich electromagnetic control capabilities and degrees of freedom in past years. As is well known, for passive metasurfaces, their functionalities cannot be further expanded accordingly once prototypes are established. Therefore, reconfigurable metasurfaces, utilizing active devices to replace geometric changes in passive structures, have received widespread attention, especially with the development of wireless communication recently. In reconfigurable metasurfaces, artificial meta-atoms are composed of active devices and passive structures combined together. However, these two modules are usually utilized as a whole due to the tight coupling of the active devices and the passive structures, which results in passive structures not receiving sufficient attention and being utilized as independent degrees of freedom. In this article, we propose the concept of weakly coupled reconfigurable metasurfaces in transmissive systems, enabling independent control of active and passive modules through weak coupling. As the proof of concept, a simple weakly coupled system is proposed, which can realize the transmission wavefront engineering through the geometric changes of meta-structures in passive mode, while achieving switching between transmission and reflection states in active mode, respectively. Our exploration lies in making use of the physical structure, which is easily neglected in traditional reconfigurable metasurface design, emphasizing the collaborative work of active and passive modules, exploring more available variables within the same aperture, and providing a potential solution for balancing functionality and resource consumption in practical applications.

关键词： modules coupling weakly

Thermal noise-driven resonant sensors

在线全文

学校读者我要写书评

暂无评论

Microsystems & Nanoengineering 2024年第3期10卷 259-271页

作者： Yan Qiao Alaaeldin Elhady Mohamed Arabi Eihab Abdel-Rahman Wenming Zhang School of mechanical engineering Shanghai Jiao Tong UniversityShanghaiChina department of Systems Design engineering University of WaterlooWaterlooONCanada

MEMS/NEMS resonant sensors hold promise for minute mass and force ***,one major challenge is that conventional externally driven sensors inevitably encounter undesired intrinsic noise,which imposes a fundamental limitation upon their signal-to-noise ratio(SNR)and,consequently,the ***,this restriction becomes increasingly pronounced as sensors shrink to the *** this work,we propose a counterintuitive paradigm shift that turns intrinsic thermal noise from an impediment to a constituent of the sensor by harvesting it as the driving force,obviating the need for external actuation and realizing‘noise-driven’*** sensors employ the dynamically amplified response to thermal noise at resonances for stimulus *** demonstrate that lightly damped and highly compliant nano-structures with high aspect ratios are promising candidates for this class of *** overcome the phase incoherence of the drive force,three noise-enabled quantitative sensing mechanisms are *** validated our sensor paradigm by experimental demonstrating noise-driven pressure and temperature ***-driven sensors offer a new opportunity for delivering practical NEMS sensors that can function at room temperature and under ambient pressure,and a development that suggests a path to cheaper,simpler,and low-power-consumption sensors.

关键词： noise resonant overcome

Review on Lithium-ion Battery PHM from the Perspective of Key PHM Steps

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of mechanical engineering 2024年第4期37卷 1-22页

作者： Jinzhen Kong Jie Liu Jingzhe Zhu Xi Zhang Kwok-Leung Tsui Zhike Peng Dong Wang School of mechanical engineering Hebei University of TechnologyTianjin 300401China School of mechanical engineering Shanghai Jiao Tong UniversityShanghai 200240China Grado department of Industrial and Systems engineering Virginia Polytechnic Institute and State UniversityBlacksburg 24061USA School of mechanical engineering Ningxia UniversityNingxia 750021China

Prognostics and health management(PHM)has gotten considerable attention in the background of Industry *** PHM contributes to the reliable and safe operation of electric ***,relevant reviews are still continuously updated over *** this paper,we browsed extensive literature related to battery PHM from 2018to 2023 and summarized advances in battery PHM field,including battery testing and public datasets,fault diagnosis and prediction methods,health status estimation and health management *** last topic includes state of health estimation methods,remaining useful life prediction methods and predictive maintenance *** of these categories is introduced and discussed in *** on this survey,we accordingly discuss challenges left to battery PHM,and provide future research *** research systematically reviews recent research about battery PHM from the perspective of key PHM steps and provide some valuable prospects for researchers and practitioners.

关键词： Lithium-ion batteries Prognostics and health management Remaining useful life State of health Predictive maintenance

Investigation of performance and emission characteristics using ethanol-blended gasoline fuel as a flex-fuel in two-wheeler vehicle mounted on a chassis dynamometer

在线全文

学校读者我要写书评

暂无评论

Clean Energy 2024年第3期8卷 174-193页

作者： Sourabh Gupta Sumit Kanchan Rupinder Kaur Sarbjot Singh Sandhu School of mechanical engineering Lovely Professional UniversityPunjabIndia Division of Innovation and Entrepreneurship Lovely Professional UniversityPunjabIndia department of mechanical engineering Dr BR Ambedkar National Institute of TechnologyJalandharIndia

This study investigated the performance and emissions of flex fuels in a 110-cc BS6-compliant fuel-injected two-wheeler without ethanol adaptation *** tests were carried out under controlled conditions on a chassis dynamometer at 1000,2000 and 3000 *** ethanol blends from 10%ethanol(E10)to 85%ethanol(E85).Parameters examined included brake power(BP)output,brake-specific fuel consumption(BSFC),peak in-cylinder pressure and exhaust ***,including carbon monoxide(CO),hydrocarbons(HC),nitrogen oxide(NOx)and unregulated emissions,were also *** the percentages of the ethanol blend increased from E10 to E85,there was a noticeable improvement in power *** 1000 r.p.m.,the BP ranged from 2.4 to 4.6 kW for different *** BSFC and the peak in-cylinder pressure followed a similar pattern,indicating enhanced performance and fuel efficiency with higher ethanol ***,using E85 at 1000 *** in a significant 41.08%reduction in exhaust temperature compared with E10,although this difference decreased with higher blend ***,replacing E10 with E85 at 1000 *** CO and HC emissions by 9.17%and 38.34%,*** contrast,NOx emissions increased at all *** with higher-ethanol blends,peaking at a 415 parts per million increase at 3000 ***,unregulated emissions decreased significantly with increased *** ethanol *** summary,the use of flex-fuel blends in a two-wheeler resulted in a modest increase in BP output,improved fuel efficiency and lower CO and HC *** findings are vital for optimizing ethanol blend utilization in two-wheeler engines under low-load conditions,considering both performance and environmental aspects.

关键词： flex fuel ethanol regulated emissions unregulated emissions chassis dynamometer performance characteristics

Mirrorless MEMS imaging:a nonlinear vibrational approach utilizing aerosol-jetted PZT-actuated fiber MEMS scanner for microscale illumination

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Microsystems & Nanoengineering 2024年第1期10卷 175-192页

作者： Wei-Chih Wang Ming-Yao Li Kuan-Chang Peng Yi-Feng Hsu Benjamin Estroff Pao-Yun Yen David Schipf Wen-Jong Wu department of Power mechanical engineering National Tsing Hua UniversityNo.101Section 2Kuang-Fu RoadHsinchuTaiwan 30013China Institute of Nanoengineering and Microsystems National Tsing Hua UniversityNo.101Section 2Kuang-Fu RoadHsinchuTaiwan 30013China department of mechanical engineering University of WashingtonSeattleWA 98195USA department of Electrical engineering University of WashingtonSeattleWA 98195USA department of engineering Science and Ocean engineering National Taiwan UniversityTaiwanChina

This study introduces a novel image capture and lighting techniques using a cutting-edge hybrid MEMS scanner system designed for compact microscopic *** scanner comprises a tapered optical fiber waveguide and innovative aerosol-jet printed PZT(lead zirconate titanate)bimorph push-pull actuators on a stainless-steel substrate,effectively addressing issues that are commonly associated with PZT on silicon substrates such as fracture and layer *** leveraging nonlinear vibration,the scanner achieves a spiral scan pattern from a single signal input,in addition to the expected two-dimensional scanning and target illumination from two phase-shifted *** capability is further enhanced by a novel process to taper the optical fiber,which reduces illumination scattering and tunes the fiber to the resonant frequencies of the *** precisely tapered tip enables large fields of view while maintaining independent 2-axis scanning through one-degree-of-freedom *** validation showcases the successful generation of a spiral scan pattern with a 60μm diameter scan area and a 10 Hz frame rate,effectively reconstructing scanned images of 5μm lines,cross patterns(15μm in length with a 5μm gap),and structures of a Psychodidae wing.

关键词： steel fiber scanner