检索结果-南通市图书馆

Effects of Rattling Behavior of K and cd Atoms along Different Directions in Anisotropic KcdAs on Lattice Thermal Transport and Thermoelectric Properties

在线全文

学校读者我要写书评

暂无评论

enERGY & enVIRONMenTAL MATERIALS 2024年第6期7卷 388-398页

作者： Wang, Yue Zhao, Yinchang Ni, jun Dai, Zhenhong Yantai Univ Dept Phys Yantai 264005 Peoples R China Tsinghua Univ Dept Phys State Key Lab Low Dimens Quantum Phys Beijing 100084 Peoples R China Frontier Sci ctr Quantum Informat Beijing 100084 Peoples R China

We employ advanced first principles methodology, merging self-consistent phonon theory and the Boltzmann transport equation, to comprehensively explore the thermal transport and thermoelectric properties of KcdAs. Notably, the study accounts for the impact of quartic anharmonicity on phonon group velocities in the pursuit of lattice thermal conductivity and investigates 3ph and 4ph scattering processes on phonon lifetimes. Through various methodologies, including examining atomic vibrational modes and analyzing 3ph and 4ph scattering processes, the article unveils microphysical mechanisms contributing to the low kappa(L) within KcdAs. Key features include significant anisotropy in cd atoms, pronounced anharmonicity in K atoms, and relative vibrations in non-equivalent As atomic layers. cd atoms, situated between As layers, exhibit rattling modes and strong lattice anharmonicity, contributing to the observed low kappa(L). Remarkably flat bands near the valence band maximum translate into high PF, aligning with ultralow kappa(L) for exceptional thermoelectric performance. Under optimal temperature and carrier concentration doping, outstanding ZT values are achieved: 4.25 (a(b)-axis, p-type, 3 x 10(19) cm(-3), 500 K), 0.90 (c-axis, p-type, 5 x 10(20) cm(-3), 700 K), 1.61 (a(b)-axis, n-type, 2 x 10(18) cm(-3), 700 K), and 3.06 (c-axis, n-type, 9 x 10(17) cm(-3), 700 K).

关键词： anharmonic lattice dynamics electron transport characteristics first principles calculation lattice thermal transport octahedron thermoelectric properties TOTAL-enERGY cALcULATIONS FIGURE cONDUcTIVITY MERIT cRYSTALS LIMIT HEAT PBSE PBTE

Directly predicting N2 electroreduction reaction free energy using interpretable machine learning with non-DFT calculated features

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10期97卷 139-148页

作者： Yaqin Zhang Yuhang Wang Ninggui Ma jun Fan Department of Materials Sc.ence and engineering City University of Hong Kong center for Advanced Nuclear Safety and Sustainable Development City University of Hong Kong Department of Mechanical engineering City University of Hong Kong

Electrocatalytic nitrogen reduction to ammonia has garnered significant attention with the blooming of single-atom catalysts（SAcs）,showcasing their potential for sustainable and energy-effic.ent ammonia ***,cost-effectively designing and screening effic.ent electrocatalysts remains a *** this study,we have successfully established interpretable machine learning（ML） models to evaluate the catalytic activity of SAcs by directly and accurately predicting reaction Gibbs free *** models were trained using non-density functional theory（DFT） calculated features from a dataset comprising 90 graphene-supported *** results underscore the superior prediction accuracy of the gradient boosting regression（GBR） model for both Δg（N2→NNH） and ΔG（NH2→NH3）,boasting coeffic.ent of determination（R2） score of 0.972 and 0.984,along with root mean square error（RMSE） of 0.051 and 0.085 eV,***,feature importance analysis elucidates that the high accuracy of GBR model stems from its adept capture of characteristics pertinent to the active center and coordination environment,unveilling the significance of elementary descriptors,with the colvalent radius playing a dominant ***,Shapley additive explanations（SHAP） analysis provides global and local interpretation of the working mechanism of the GBR *** analysis identifies that a pyrrole-type coordination（flag=0）,d-orbitals with a moderate occupation（Nd=5）,and a moderate difference in covalent radius(rTM-avenear 140 pm) are conducive to achieving high ***,we extend the prediction of activity to more catalysts without additional DFT calculations,validating the reliability of our feature engineering,model training,and design *** findings not only highlight new opportunity for accelerating catalyst design using non-DFT calculated features,but also shed light on the working mechanism of "black box" ML ***,the model provides valuable guidanc

关键词： Graphene Interpretable machine learning Nitrogen reduction Non-DFT features Single-atom catalyst

Gas microchannel plate-pixel detector for X-ray polarimetry

在线全文

学校读者我要写书评

暂无评论

Nuclear Sc.ence and Techniques 2024年第5期35卷 60-73页

作者： Huan-Bo Feng Hong-Bang Liu Dong Wang Zi-Li Li Shu-Lin Liu Qian Liu Hang-Zhou Li Bin-Long Wang Yan-jun Xie Zong-Wang Fan Hui Wang Ran c.en Di-Fan Yi Rui-Ting Ma Fei Xie Bo Peng Xiang-Ming Sun Jin Li en-Wei Liang Present Address:Guangxi Key Laboratory for Relativistic Astrophysics School of Physical Science and TechnologyGuangxi UniversityNanning 530004China PLAc Key Laboratory of Quark and Lepton Physics(MOE)Central China Normal UniversityWuhan 430079China School of Sc.ence Huzhou UniversityHuzhou 313000China Institute of High energy Physics Chinese Academy of SciencesBeijing 100049China School of Nuclear Sc.ence and Technology University of Chinese Academy of SciencesBeijing 100049China School of Physical Sc.ence University of Chinese Academy of SciencesBeijing 100049China The 13th Research Institute of china Electronics Technology Group corporation Shijiazhuang 050057China

POLAR-2 is a gamma-ray burst(GRB)polarimeter that is designed to study the polarization in GRB radiation emissions,aiming to improve our knowledge of related ***-2 is expected to utilize an on-board polarimeter that is sensitive to soft X-rays(2-10 keV),called low-energy polarization *** have developed a new soft X-ray polari-zation detector prototype based on gas microchannel plates(GMcPs)and pixel chips(Topmetal).The GMcPs have bulk resistance,which prevents charging-up effects and ensures gain stability during *** detector is composed of low outgassing materials and is gas-sealed using a laser welding technique,ensuring long-term stability.A modulation factor of 41.28%±0.64% is obtained for a 4.5 keV polarized X-ray beam.A residual modulation of 1.96%±0.58% at 5.9 keV is observed for the entire sensitive area.

关键词： X-ray polarimetry Gas microchannel plate-pixel detector Gamma-ray bursts

Effect of heat treatment on microstructure and mechanical properties of selective laser-melted PH13-8Mo stainless steel

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2024年第4期31卷 945-955页

作者： Yuan Zhang Xiang Liu chang-jun Wang chang Liu School of Material Sc.ence and engineering Kunming University of Science and TechnologyKunming 650093YunnanChina central Iron&Steel Research Institute co. Ltd.Beijing 100081China

PH13-8Mo stainless steel powder with high sphericity and well fluidity was prepared by the plasma rotating electrode *** formed parts with ultra-high purity were manufactured by selective laser *** tensile and impact mechanical properties of the printed parts under three heat treatment regimes were compared to those without heat *** microstructure,grain orientation and phase composition were characterized by electron-backscatter diffraction,X-ray diffraction and transmission electron *** characterization results reveal that the addition of heat treatment makes the grains enlarge,and after different heat treatments,the average grain size from 1.51μm in the printed state increases to 2.78,3.09 and 2.06μm,*** formed parts are mainly composed of martensite and retained ***,the NiAl and M23c precipitates form,which are the major strengthening phases of PH13-8Mo stainless *** optimal heat treatment process is 925℃×1 h water cooling(Wc)+0℃×2 h air cooling(Ac)+540℃×4 h *** this heat treatment process,PH13-8Mo formed parts have the optimal comprehensive mechanical properties:the tensile strength,yield strength and impact energy KU2 are 1492 MPa,1432 MPa and 63 J,*** strengthening and toughening via heat treatment are mainly attributed to dislocation strengthening,the formation of NiAl and M23co precipitates and the change of volume fraction of the retained austenite.

关键词： High-strength stainless steel-Selective laser melting-Heat treatment Microstructure Mechanical property

Wearable Triboelectric Nanogenerators Based on Printed Polyvinylidene Fluoride Films Incorporated with cobalt-Based Metal-Organic Framework for Self-Powered Mobile Electronics

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

energy & environmental Materials 2024年第4期7卷 396-403页

作者： Myeong-Hyeon Kim Sang-Joon Park Tae-jun Ha Department of Electronic Materials engineering Kwangwoon University

In this study,wearable triboelectric nanogenerators comprising bar-printed polyvinylidene fluoride (PVDF) films incorporated with cobalt-based metalorganic framework (co-MOF) were *** enhanced output performance of the Tencs was attributed to the phase transition of PVDF from α-crystals to β-crystals,as facilitated by the incorporation of the MOF.

关键词： bar printing phase transition polyvinylidene fluoride incorporated with cobalt-based metal–organic framework self-powered mobile electronics wearable triboelectric nanogenerators

Quantitative characterizations of anisotropic dynamic properties in organic-rich shale with different kerogen content

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Petroleum Sc.ence 2024年第2期21卷 855-865页

作者： Jian-Yong Xie Yan-Ping Fang Xing-Hua Wu Jian'er Zhao jun-c.eng Dai jun-Xing cao Ji-Xin Deng State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Chengdu University of TechnologyChengdu610059SichuanChina Key Lab of Earth Exploration&Information Techniques of Ministry of Education Geophysical InstituteChengdu University of TechnologyChengdu610059SichuanChina Petrochina Southwest Oil&Gasfield company Chengdu610017SichuanChina

Understanding the quantitative responses of anisotropic dynamic properties in organic-rich shale with different kerogen content(Kc)is of great significance in hydrocarbon exploration and *** controlled experiments with a single variable is challenging for natural shales due to their high variations in components,diagenesis conditions,or pore *** employed the hot-pressing technique to construct 11 well-controlled artificial shale with varying *** artificial shale samples were successive machined into prismatic shape for ultrasonic measurements along different *** revealed bedding perpendicular P-wave velocities are more sensitive to the increasing Kc than bedding paralleling velocities due to the preferential alignments of *** elastic stiffnesses except c_(13)are generally decreasing with the increasing Kc,the variation of c_(1) and c_(33)on kerogen content are more sensitive than those of c_(44)and c_(66).Apparent dynamic mechanical parameters(v and E)were found to have linear correlation with the true ones from complete anisotropic equations independent of Kc,which hold value towards the interpretation of well logs consistently across formations,Anisotropic mechanical parameters(ΔE and brittlenessΔB)tend to decrease with the reducing Kc,withΔB showing great sensitivity to Kc *** the range of low Kc(correlation with Kc,and the V_(P)/V_(S) ratio magnitude of less than 1.75may serve as a significant characterization for highly organic-rich(>10%)shale,compilation of data from natural organic rich-shales globally verified the similar systematic relationships that can be empirically used to predict the fraction of Kc in shales.

关键词： Elastic properties Organic shale Anisotropy Kerogen content Physical modeling

Unraveling the role of iron on Ni-Fe alloy nanoparticles during the electrocatalytic ethanol-to-acetate process

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第4期17卷 2328-2336页

作者： junshan Li Luming Li Xinyu Ma jun Wang jun Zhao Yu Zhang Ren He Yaoyue Yang Andreu cabot Yongfa Zhu Institute for Advanced Study Chengdu University610106 ChengduChina State Key Laboratory of environmental-Friendly energy Materials Southwest University of Science and TechnologyMianyang 621010China college of Food and Biological engineering Chengdu UniversityChengdu 610106China School of chemistry and environment Southwest Minzu UniversityChengdu 610041China Hebei Key Laboratory of Photoelectric control on Surface and Interface College of ScienceHebei University of Science and TechnologyShijiazhuang 050018China catalonia Institute for energy Research-IREc Sant Adriàde BesòsBarcelona 08930CataloniaSpain IcREA Pg.Lluís Companys 23Barcelona 08010CataloniaSpain Department of chemistry Tsinghua UniversityBeijing 100084China

The anodic electrooxidation of ethanol to value-added acetate is an excellent example of replacing the oxygen evolution reaction to promote the cathodic hydrogen evolution reaction and save ***,we present a colloidal strategy to produce Ni-Fe bimetallic alloy nanoparticles(NPs)as effic.ent electrocatalysts for the electrooxidation of ethanol in alkaline ***-Fe alloy NPs deliver a current density of 100 mA·cm^(-2) in a 1.0 M KOH solution containing 1.0 M ethanol merely at 1.5 V *** hydrogen electrode(RHE),well above the performance of other electrocatalysts in a similar *** continuous 10 h testing at this external potential,this electrode is able to produce an average of 0.49 mmol·cm^(-2)·h^(-1) of acetate with an ethanol-to-acetate Faradaic effic.ency of 80%.A series of spectroscopy techniques are used to probe the electrocatalytic process and analyze the ***,density functional theory(DFT)calculations demonstrate that the iron in the alloy NPs significantly enhances the electroconductivity and electron transfer,shifts the rate-limiting step,and lowers the energy barrier during the ethanol-to-acetate reaction pathway.

关键词： electrocatalysis ethanol oxidation reaction alloy nanoparticle acetate biorefinery

Synergistic integration of self-supported 1T/2H-WS_(2) and nitrogendoped rGO on carbon cloth for pH-universal electrocatalytic hydrogen evolution

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3期17卷 1267-1280页

作者： Feng Ming Yap Jian Yiing Loh Wee-jun Ong School of energy and chemical engineering Xiamen University MalaysiaSelangor Darul Ehsan 43900Malaysia center of Excellence for NaNo energy&catalysis Technology(cONNEcT) Xiamen University MalaysiaSelangor Darul Ehsan 43900Malaysia State Key Laboratory of Physical chemistry of Solid Surfaces College of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China Gulei Innovation Institute Xiamen UniversityZhangzhou 363200China Shenzhen Research Institute of Xiamen University Shenzhen 518057China

Hydrogen economy based on electrochemical water splitting exemplified one of the most promising means for overcoming the rapid consumption of fossil fuels and the serious deterioration of global *** development of earth-abundant,effic.ent,and durable electrocatalysts for hydrogen evolution reaction(HER)plays a vital role in the commercialization of water ***,the self-supported electrode with unique nitrogen-doped reduced graphene oxide(N-rGO)nanoflakes and WS_(2) hierarchical nanoflower that were grown directly on carbon cloth(cc)substrate(WS_(2)/N-rGO/cc)was successfully synthesized using a facile dual-step hydrothermal *** as-synthesized 50%1T/2H-WS_(2)/N-rGO/cc(WGc),which possessed high metallic 1T phase of 57%not only effic.ently exposed more active sites and accelerated mass/charge diffusion,but also endowed excellent structural lustiness,robust stability,and durability at a high current *** a result,the 50%WGc exhibited lower overpotentials and Tafel slopes of 21.13 mV(29.55 mV∙dec^(-1))and 80.35 mV(137.02 mV∙dec^(-1))as compared to 20%Pt-c/cc,respectively for catalyzing acidic and alkaline hydrogen evolution ***,the as-synthesized 50%WGc also depicted long-term stability for more than 8 h in the high-current-density regions(100 and 220 mA∙cm^(-2)).In brief,this work reveals a self-supported electrode as an extraordinary alternative to Pt-based catalysts for HER in a wide pH range,while paving a facile strategy to develop advanced electrocatalysts with abundant heterointerfaces for practical applications in energy-saving hydrogen production.

关键词： self-supported electrocatalyst carbon-based substrate phase engineering pH-universal water splitting

Pion-photon and kaon-photon transition distribution amplitudes in the Nambu–Jona-Lasinio model

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 c 2024年第8期48卷 94-103页

作者： Jin-Li Zhang jun Wu Department of Mathematics and Physics Nanjing Institute of TechnologyNanjing 211167China National Laboratory of Solid State Microstructures Department of PhysicsNanjing UniversityNanjing 210093China

The Nambu–Jona-Lasinio model is utilized to investigate the pion-and kaon-photon leading-twist transition distribution amplitudes using proper time ***,the properties of the vector and axial vector pion-photon transition distribution amplitudes are examined,and the results meet the desired *** study involves sum rule and polynomiality *** vector and axial vector pion-photon transition form factors that are present in theπ^(+)→γe^(+)νprocess are the first Mellin moments of the pion-photon transition distribution *** vector transition form factor originates from the internal structure of hadrons,the axial current can be coupled to a pion,this pion is virtual,and its contribution will be present independently of the external *** kaon transition form factors are *** vector form factor's value at zero momentum transfer is determined by the axial anomaly,while this is not the case for the axial *** vector and axial form factors,as well as the neutral pion vector form factor F_(πγγ)(t),are *** to our findings,the pion axial transition form factor is harder than the vector transition form factor and harder than the electromagnetic form *** also discuss the link betweenπ−γandγ−πtransitions distribution amplitudes.

关键词： transition form factors NJL model transition distribution amplitudes