检索结果-南通市图书馆

Interfacial stress engineering toward enhancement of ferroelectricity in Al doped HfO_(2)thin films

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 Physics B 2024年第9期33卷 637-643页

作者： S X Chen m m Chen Y Liu D W Cao G j Chen Department of microelectronics Jiangsu UniversityZhenjiang 212013China Department of Physics Jiangsu UniversityZhenjiang 212013China Guangdong–Hong Kong–macao joint Laboratory for Intelligent micro-Nano Optoelectronic Technology Foshan UniversityFoshan 528225China

Ferroelectric HfO_(2)has attracted much attention owing to its superior ferroelectricity at an ultra-thin thickness and good compatibility with Si-based complementary metal-oxide-semiconductor(CmOS)***,the crystallization of polar orthorhombic phase(o-phase)HfO_(2)is less competitive,which greatly limits the ferroelectricity of the as-obtained ferroelectric HfO_(2)thin ***,the crystallization of o-phase HfO_(2)can be thermodynamically modulated via interfacial stress *** this paper,the growth of improved ferroelectric Al doped HfO_(2)(HfO_(2):Al)thin films on(111)-oriented Si substrate has been *** analysis has suggested that nonpolar monoclinic HfO_(2):Al grown on(111)-oriented Si substrate suffered from a strong compressive strain,which promoted the crystallization of(111)-oriented o-phase HfO_(2)in the as-grown HfO_(2):Al thin *** addition,the in-plane lattice of(111)-oriented Si substrate matches well with that of(111)-oriented o-phase HfO_(2),which further thermally stabilizes the o-phase HfO_(2).Accordingly,an improved ferroelectricity with a remnant polarization(2P_(r))of 26.7C/cm^(2) has been *** results shown in this work provide a simple way toward the preparation of improved ferroelectric HfO_(2)thin films.

关键词： improved ferroelectricity interfacial stress engineering compressive strain HfO_(2)

Nano-enhanced solid-state hydrogen storage:Balancing discovery and pragmatism for future energy solutions

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第10期17卷 8729-8753页

作者： Chaochao Dun Xinyi Wang Linfeng Chen Sichi Li Hanna m.Breunig jeffrey j.Urban The molecular Foundry Lawrence Berkeley National Laboratory BerkeleyBerkeleyCA 94720USA Energy Analysis and Environmental Impacts Division Lawrence Berkeley National LaboratoryBerkeleyCA 94720USA Lawrence Livermore National Laboratory LivermoreCA 94550USA

Nanomaterials have revolutionized the battery industry by enhancing energy storage capacities and charging speeds,and their application in hydrogen(H_(2))storage likewise holds strong potential,though with distinct challenges and mechanisms.H_(2) is a crucial future zero-carbon energy vector given its high gravimetric energy density,which far exceeds that of liquid ***,its low volumetric energy density in gaseous form currently requires storage under high pressure or at low *** review critically examines the current and prospective landscapes of solid-state H_(2) storage technologies,with a focus on pragmatic integration of advanced materials such as metal-organic frameworks(mOFs),magnesium-based hybrids,and novel sorbents into future energy *** materials,enhanced by nanotechnology,could significantly improve the efficiency and capacity of H_(2) storage systems by optimizing H_(2) adsorption at the nanoscale and improving the kinetics of H_(2) uptake and *** discuss various H_(2) storage mechanisms—physisorption,chemisorption,and the Kubas interaction—analyzing their impact on the energy efficiency and scalability of storage *** review also addresses the potential of“smart mOFs”,single-atom catalyst-doped metal hydrides,mXenes and entropy-driven alloys to enhance the performance and broaden the application range of H_(2) storage systems,stressing the need for innovative materials and system integration to satisfy future energy ***-throughput screening,combined with machine learning algorithms,is noted as a promising approach to identify patterns and predict the behavior of novel materials under various conditions,significantly reducing the time and cost associated with experimental *** closing,we discuss the increasing involvement of various companies in solid-state H_(2) storage,particularly in prototype vehicles,from a techno-economic *** forward-looking perspective underscores t

关键词： nanomaterials nanotechnology solid-state H_(2)storage techno-economic analysis model-driven material development processes

Drought events influence nutrient canopy exchanges and green leaf partitioning during senescence in a deciduous forest

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Forest Ecosystems 2024年第1期11卷 110-119页

作者： j.Touche C.Calvaruso P.De Donato m.-P.Turpault INRAE BEFF-54000NancyFrance UmR 7359 GeoRessourcesFaculte des Sciences-Campus des Aiguillettes54506Vandoeuvre Les NancyFrance EcoSustain Environmental Engineering OfficeResearch and DevelopmentKanfen57330France

The increase in the frequency and intensity of drought events expected in the coming decades in Western Europe may disturb forest biogeochemical cycles and create nutrient deficiencies in *** possible origin of nutrient deficiency is the disturbance of the partitioning of the green leaf pool during the leaf senescence period between resorption,foliar leaching and senesced ***,the effects of drought events on this partitioning and the consequences for the maintenance of tree nutrition are poorly *** experiment in a beech forest in meuse(France)was conducted to assess the effect of drought events on nutrient canopy exchanges and on the partitioning of the green leaf pool during the leaf senescence *** aim was to identify potential nutritional consequences of droughts for *** nutrient dynamics,including resorption,chemistry of green and senesced leaves,foliar absorption and leaching in mature beech stands from 2012 to 2019 allowed us to compare the nutrient exchanges for three nondry and three dry years(i.e.,with an intense drought event during the growing season).During dry years,we observed a decrease by almost a third of the potassium(K)partitioning to resorption(*** efficiency),thus reducing the K reserve in trees for the next growing *** result suggests that with the increased drought frequency and intensity expected for the coming decades,there will be a risk of potassium deficiency in trees,as already observed in a rainfall exclusion experiment on the same study *** foliar leaching and higher parititioning to the senesced leaves for K and phosphorus(P)were also *** addition,a slight increase in nitrogen(N)resorption efficiency occurred during dry years which is more likely to improve tree *** calcium(Ca)negative resorption decreased,with no apparent consequence in our study *** results show that nutrient exchanges in the canopy and the partitioning of the green leaf

关键词： Natural drought Beech forest Canopy Resorption Foliar leaching Senesced leaves Nutrition

Automating selective area electron diffraction phase identification using machine learning

在线全文

学校读者我要写书评

暂无评论

journal of materiomics 2024年第4期10卷 896-905页

作者： m.mika N.Tomczak C.Finney j.Carter A.Aitkaliyeva Nuclear Engineering Program in Department of materials Science University of Florida100 Rhines HallGainesville32611FLUSA Department of materials Science&Engineering Case Western Reserve University2111 Martin Luther King Jr DrCleveland44106OHUSA

Selective area electron diffraction(SAED)patterns can provide valuable insight into the structure of a ***,the manual identification of collected patterns can be a significant bottleneck in the overall phase classification *** this work,we utilize the recent advances in computer vision and machine learning(mL)to automate the indexing of SAED *** performance of six different mL algorithms is demonstrated using metallic plutonium-zirconium *** most successful approach trained a neural network(NN)to make a classification of the phase and zone axis,and then utilized a second NN to synthesize multiple independent predictions of different tilts in a single sample to make an overall phase *** results demonstrate that automated SAED phase identification using mL is a viable route to accelerate materials characterization.

关键词： Selective area electron diffraction machine learning Phase identification metallic fuels Pu alloys

Influence of the zigzag fins and inlet arrangements on the cooling proficiency of the mini-channel heat sink

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Propulsion and Power Research 2024年第2期13卷 194-206页

作者： A.Torbatinezhad Y.Pahamli m.j.Hosseini R.bahrampoury School of mechanical Engineering Babol University of TechnologyBabolIran Department of mechanical Engineering Semnan UniversitySemnanIran Department of mechanical Engineering Faculty of EngineeringGolestan UniversityGorganIran Department of mechanical Engineering K.N.Toosi University of TechnologyTehranIran

mini-channel heatsinks are one of the most effective thermal management methods for high heatﬂux devices due to the high performance of convective heat *** recent years,various techniques have been innovated to improve the thermal proﬁciency of the mini-channel *** of these are taking advantage ofﬁns’structural designs and ar-rangements of inlets and *** zigzagﬁns and channels were considered in the previous works in heatsinks,and researchers analyzed their cooling enhancement ***,in the present work,a combined cooling technique,considering new-type zigzagﬁns’geometrical parameters(arrangement,length,and height)causes turbulenceﬂow and higher convective heat transfer along with different positionings ofﬂow inlet and outlets resulting in superior temper-ature uniformity,is proposed to evaluate their impacts on the cooling proﬁciency of the heat sink versus different Reynolds *** assess the thermal and hydraulic performance of the proposed heatsink,different parameters,including temperature contours,Nusselt numbers,thermal resistance,and entropy generation are *** a result,it is observed that in the case demonstrating the best thermal performance,the Nusselt number,pressure drop,thermal resistance,and entropy generation are respectively 37.13,4586.46 Pa,0.000078 m^(2)·K/W,and 0.1078 W/K in the best *** well,it is found that by changing the arrangements of inlets and outlets,the Nusselt number,and thermal resistance are improved by 12%and 13%,***,the proposed mini-channel heat sink could be used as a high-performance thermal management system for electronic devices in different industries,including energy,solar,and medical sectors.

关键词： Thermal management Heat transfer enhancement mini-channel heatsink Zigzagﬁn Entropy generation Electronic cooling

magnetic Topological Dirac Semimetal Transition Driven by SOC in Eumg_(2)Bi_(2)

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 Physics Letters 2024年第1期41卷 63-67页

作者：王佳萌钱浩吉姜琦乔山叶茂 State Key Laboratory of Functional materials for Informatics Shanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai 200050China Center of materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Research Center for Intelligent Chips and Devices Zhejiang LabHangzhou 311121China Center for Transformative Science ShanghaiTech UniversityShanghai 201210China School of Physical Science and Technology ShanghaiTech UniversityShanghai 201210China Shanghai Synchrotron Radiation Facility Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201204China

magnetic topological semimetals have been at the forefront of condensed matter physics due to their ability to exhibit exotic transport *** the interplay between magnetic and topological orders in systems with broken time-reversal symmetry is crucial for realizing non-trivial quantum *** delve into the electronic structure of the rare-earth-based antiferromagnetic Dirac semimetal Eumg_(2)Bi_(2) using first-principles calculations and angle-resolved photoemission *** calculations reveal that the spin-orbit coupling(SOC)in Eumg_(2)Bi_(2) prompts an insulator to topological semimetal transition,with the Dirac bands protected by crystal *** linearly dispersive states near the Fermi level,primarily originating from Bi 6p orbitals,are observed on both the(001)and(100)surfaces,confirming that Eumg_(2)Bi_(2) is a three-dimensional topological Dirac *** research offers pivotal insights into the interplay between magnetism,SOC and topological phase transitions in spintronics applications.

关键词： spectroscopy topological Dirac

The replication crisis and its relevance to Earth Science studies:Case studies and recommendations

在线全文

学校读者我要写书评

暂无评论

Geoscience Frontiers 2024年第4期15卷 304-314页

作者： Stephen j.Puetz Kent C.Condie Kurt Sundell Nick m.W.Roberts Christopher j.Spencer Slah Boulila Qiuming Cheng 475 Atkinson Dr Suite 704HonoluluHI 96814USA New mexico Institute of mining and Technology SocorroNM 87801USA Idaho State University PocatelloID 83209USA Geochronology and Tracers Facility British Geological SurveyKeyworthNottingham NG125GGUK Queen’s University Department of Geological Sciences and Geological EngineeringKingstonOntario K7L 3N6Canada Sorbonne Université CNRSInstitut des Sciences de la Terre ParisParisFrance State Key Laboratory of Geological Processes and mineral Resources China University of GeosciencesWuhan 430074China

Numerous scientific fields are facing a replication crisis,where the results of a study often cannot be replicated when a new study uses independent *** issue has been particularly emphasized in psychology,health,and medicine,as incorrect results in these fields could have serious consequences,where lives might be at *** other fields have also highlighted significant replication problems,the Earth Sciences seem to be an *** paucity of Earth Science research aimed at understanding the replication crisis prompted this ***,this work aims to fill that gap by seeking to replicate geological results involving various types of *** identify and discuss 11 key variables for replicating U-Pb age distributions:independent data,global sampling,proxy data,data quality,disproportionate non-random sampling,stratigraphic bias,potential filtering bias,accuracy and precision,correlating time-series segments,testing assumptions and divergent analytical methods,and analytical *** while this work primarily focuses on U-Pb age distributions,most of these factors(or variations of them)also apply to other geoscience ***,some of the discussions involve time-series consisting ofεHf,δ18O-zircon,14C,10Be,marineδ13C,and marineδ*** then provide specific recommendations for minimizing adverse effects related to these factors,and in the process enhancing prospects for replicating geological results.

关键词： Replication crisis Replicability Independent data Global time-series Globality index Filtered data

The initial stages of Li_(2)O_(2) formation during oxygen reduction reaction in Li-O_(2) batteries:The significance of Li_(2)O_(2) in charge-transfer reactions within devices

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

journal of Energy Chemistry 2024年第1期88卷 223-231,I0006页

作者： Daniela m.josepetti Bianca P.Sousa Simone A.j.Rodrigues Renato G.Freitas Gustavo Doubek Advanced Energy Storage Division LABCenter for Innovation on New EnergiesSchool of Chemical EngineeringUniversity of CampinasAv Albert Einstein 50013083-852CampinasSPBrazil Institute of Physics&Department of Chemistry Laboratory of Computational MaterialsFederal University of Mato Grosso78060-900CuiabáMTBrazil

Lithium-oxygen batteries are a promising technology because they can greatly surpass the energy density of lithium-ion ***,this theoretical characteristic has not yet been converted into a real device with high *** with air contamination,metallic lithium reactivity,and complex discharge and charge reactions are the main issues for this technology.A fast and reversible oxygen reduction reaction(ORR)is crucial for good performance of secondary batteries',but the partial knowledge of its mechanisms,especially when devices are concerned,hinders further *** this perspective,the present work uses operando Raman experiments and electrochemical impedance spectroscopy(EIS)to assess the first stages of the discharge processes in porous carbon electrodes,following their changes cycle by cycle at initial operation.A growth kinetic formation of the discharge product signal(Li_(2)O_(2))was observed with operando Raman,indicating a first-order reaction and enabling an analysis by a microkinetic *** solution mechanism in the evaluated system was ascribed for an equivalent circuit with three time *** the time constant for the anode interface reveals to remain relatively constant after the first discharge,its surface seemed to be more *** model indicated that the reaction occurs at the Li_(2)O_(2) surface,decreasing the associated resistance during the initial discharge ***,the growth of Li_(2)O_(2) forms a hetero-phase between Li_(2)O_(2)/electrolyte,while creating a more compact and homogeneous on the Li_(2)O_(2)/cathode *** methodology here described thus offers a way of directly probing changes in surface chemistry evolution during cycling from a device through EIS analysis.

关键词： Li-O_(2)battery Operando Raman analysis Equivalent circuit modeling Time-constant distribution

Interactive mechanism and friction modelling of transient tribological phenomena in metal forming processes: A review

在线全文

学校读者我要写书评

暂无评论

Friction 2024年第3期12卷 375-395页

作者： Xiao YANG Heli LIU Lemeng ZHANG Yiran HU Denis j.POLITIS mohammad m.GHARBI Liliang WANG Department of mechanical Engineering Imperial College LondonLondon SW72AZUK Department of mechanical and manufacturing Engineering University of CyprusNicosia 1678Cyprus Quaker Houghton Deutschland GmbH Dortmund 44319Germany

The accurate representation of tribological boundary conditions at the tool–workpiece interface is crucial for analysis and optimization of formability,material flow,and surface quality of components during metal forming *** has been found that these tribological conditions vary spatially and historically with process parameters and contact *** time-dependent tribological behaviours are also known as transient tribological phenomena,which are widely observed during forming processes and many other manufacturing application ***,constant friction values are usually assigned to represent complex and dynamic interfacial conditions,which would introduce deviations in the relevant *** this paper,transient tribological phenomena and the contemporary understanding of the interaction between friction and wear are reviewed,and it has been found that these phenomena are induced by the transitions of friction mechanisms and highly dependent on complex loading conditions at the *** modelling techniques for transient behaviours for metal forming applications are also *** accurately describe the evolutionary friction values and corresponding wear during forming,the advanced interactive friction modelling has been established for different application scenarios,including lubricated condition,dry sliding condition(metal-on-metal contact),and coated system.

关键词： transient tribological phenomena interactive friction mechanism modelling techniques metal forming