检索结果-南通市图书馆

Coexistence of plastic and partially diffusive phases in a helium-methane compound

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

National Science Review 2020年第10期7卷 1540-1547页

作者： Hao Gao Cong Liu Andreas Hermann Richard J.Needs Chris J.Pickard Hui-Tian Wang Dingyu Xing Jian Sun National Laboratory of Solid State Microstructures School of Physics and Collaborative Innovation Center of Advanced MicrostructuresNanjing University Centre for Science at extreme Conditions and The School of Physics and Astronomy The University of Edinburgh Theory of Condensed Matter Group Cavendish Laboratory Department of materials Science & Metallurgy University of Cambridge Advanced institute for materials Research Tohoku University

Helium and methane are major components of giant icy planets and are abundant in the universe. However,helium is the most inert element in the periodic table and methane is one of the most hydrophobic molecules, thus whether they can react with each other is of fundamental importance. Here, our crystal structure searches and first-principles calculations predict that a He;CH;compound is stable over a wide range of pressures from 55 to 155 GPa and a HeCH;compound becomes stable around 105 GPa. As nice examples of pure van der Waals crystals, the insertion of helium atoms changes the original packing of pure methane molecules and also largely hinders the polymerization of methane at higher pressures. After analyzing the diffusive properties during the melting of He;CH;at high pressure and high temperature, in addition to a plastic methane phase, we have discovered an unusual phase which exhibits coexistence of diffusive helium and plastic methane. In addition, the range of the diffusive behavior within the helium-methane phase diagram is found to be much narrower compared to that of previously predicted helium-water compounds. This may be due to the weaker van der Waals interactions between methane molecules compared to those in helium-water compounds, and that the helium-methane compound melts more easily.

关键词： crystal structure prediction ab initio molecular dynamics ab initio calculations high pressure and high temperature melting and phase transition collective motion

Sodium metals for single emitter strong coupling:Alternative plasmonic candidates beyond noble metals

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2024年第8期67卷 106-117页

作者： Yi Zhang Shuying Chen Yuning Han Xiulai Xu Lin Zhou National Laboratory of Solid State Microstructures Collaborative Innovation Center of Advanced MicrostructuresJiangsu Key Laboratory of Artificial Functional MaterialsCollege of Engineering and Applied SciencesNanjing UniversityNanjing 210008China School of Information and Electronic Engineering(Sussex Artificial Intelligence institute) Zhejiang Gongshang UniversityHangzhou 310018China Department of Physics&Astronomy University College LondonLondon WC1E 6BTUK State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics School of PhysicsPeking UniversityBeijing 100871China

This work provides a theoretical investigation into the strong coupling between a single quantum emitter(QE)and the surface plasmons of sodium metals in two representative plasmonic systems,i.e.,the semi-infinite metal-dielectric interface and the metal nanoparticles(NPs)of monomer/dimer *** both configurations,sodium metals exhibit distinctly stronger coupling strength and lower optical loss in the optical region than their noble metal counterparts,demonstrating the ideal candidate characteristics for single-molecule-level strong couplings with distinctly facile operation *** results provide new insights into extreme light-matter interactions with potential applications in quantum information,optical sensors,quantum chemistry,etc.

关键词： sodium metals plasmonics single quantum emitter strong coupling pseudomode

同方期刊数据库

Associative learning of a three-terminal memristor network for digits recognition

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2023年第2期66卷 209-218页

作者： Yiming REN Bobo TIAN Mengge YAN Guangdi FENG Bin GAO Fangyu YUE Hui PENG Xiaodong TANG Qiuxiang ZHU Junhao CHU Chungang DUAN Key Laboratory of Polar materials and Devices (MOE) Ministry of Education Department of ElectronicsEast China Normal University Zhejiang Lab institute of Microelectronics Beijing Innovation Center for Future Chips (ICFC) Tsinghua University Collaborative Innovation Center of extreme Optics Shanxi University

Imitating the associative intelligence of the biological brain is attractive but is poorly achieved in hardware because the complex tunable connection in neural networks is difficult to reproduce. We develop a circuit composed of a three-terminal memristor network to reproduce the biological conditioning process artificially. The synaptic weight between co-firing neurons is strengthened simultaneously by generating a feedback signal from the integrate-and-fire neuron to the gate of the synaptic memristor. The network allows the multi-associative capacity of recalling more than one digit in one circuit. Both single and multi-associative learning for recalling digital images are achieved. Furthermore, all 10 digital images from “0” to “9” are successfully recalled in an associative network with such paralleling circuits. Assisted by this associative layer, a typical classification network effectively improves the recognition rate for fragmentary digital *** work sheds light on brain-inspired artificial associative memory and provides a strategy for applications,such as object recognition with partial features and similar scenes.

关键词： artificial intelligence associative learning memristor classification network

Machine learning for predicting the outcome of terminal ballistics events

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第1期31卷 14-26页

作者： Shannon Ryan Neeraj Mohan Sushma Arun Kumar AV Julian Berk Tahrima Hashem Santu Rana Svetha Venkatesh Applied Artificial Intelligence institute(A2I2) Deakin University75 Pigdons RdWaurn PondsVIC3216Australia

Machine learning(ML) is well suited for the prediction of high-complexity,high-dimensional problems such as those encountered in terminal *** evaluate the performance of four popular ML-based regression models,extreme gradient boosting(XGBoost),artificial neural network(ANN),support vector regression(SVR),and Gaussian process regression(GP),on two common terminal ballistics’ problems:(a)predicting the V50ballistic limit of monolithic metallic armour impacted by small and medium calibre projectiles and fragments,and(b) predicting the depth to which a projectile will penetrate a target of semi-infinite *** achieve this we utilise two datasets,each consisting of approximately 1000samples,collated from public release *** demonstrate that all four model types provide similarly excellent agreement when interpolating within the training data and diverge when extrapolating outside this *** extrapolation is not advisable for ML-based regression models,for applications such as lethality/survivability analysis,such capability is *** circumvent this,we implement expert knowledge and physics-based models via enforced monotonicity,as a Gaussian prior mean,and through a modified loss *** physics-informed models demonstrate improved performance over both classical physics-based models and the basic ML regression models,providing an ability to accurately fit experimental data when it is available and then revert to the physics-based model when *** resulting models demonstrate high levels of predictive accuracy over a very wide range of projectile types,target materials and thicknesses,and impact conditions significantly more diverse than that achievable from any existing analytical *** with numerical analysis tools such as finite element solvers the ML models run orders of magnitude *** provide some general guidelines throughout for the development,application,and reporting of ML models in terminal ballist

关键词： Machine learning Artificial intelligence Physics-informed machine learning Terminal ballistics Armour

High performance columnar-like Fe2O3@carbon composite anode via yolk@shell structural design

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2020年第2期29卷 126-134页

作者： Zhiming Zheng Pei Li Jason Huang Haodong Liu Yi Zao Zhongli Hu Li Zhang Huixin Chen Ming-Sheng Wang Dong-Liang Peng Qiaobao Zhang Department of materials Science and Engineering College of MaterialsXiamen UniversityXiamen 361005FujianChina Department of Nanoengineering University of California San DiegoLa Jolla 92093CAUSA Joint Laboratory for extreme Conditions Matter Properties Southwest University of Science and TechnologyMianyang 621010SichuanChina Soochow institute for Energy and materials Innovations(SIEMIS) Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu ProvinceSoochow UniversitySuzhou 215006Jiangsu.China Xiamen institute of Rare Earth materials Haixi institutesChinese Academy of SciencesXiamen 361024Fujian.China

Conversion-type reaction anode materials with high specific capacity are attractive candidates to improve lithium ion batteries(LIBs), yet the rapid capacity fading and poor rate capability caused by drastic volume change and low electronic conductivity greatly hinder their practical applications. To circumvent these issues, the successful design of yolk@shell Fe2 O3@C hybrid composed of a columnar-like Fe2O3 core within a hollow cavity completely surrounded by a thin, self-supported carbon(C) shell is presented as an anode for high-performance LIBs. This yolk@shell structure allows each Fe2O3 core to swell upon lithiation without deforming the carbon shell. This preserves the structural and electrical integrity against pulverization, as revealed by in situ transmission electron microscopy(TEM) measurement. Benefiting from these structural advantages, the resulting electrode exhibits a high reversible capacity(1013 m Ah g-1 after80 cycles at 0.2 A g-1), outstanding rate capability(710 m Ah g-1 at 8 A g-1) and superior cycling stability(800 m Ah g-1 after 300 cycles at 4 A g-1). A Li-ion full cell using prelithiated yolk@shell Fe2 O3@C hybrid as the anode and commercial Li CoO2(LCO) as the cathode demonstrates impressive cycling stability with a capacity retention of 84.5% after 100 cycles at 1 C rate, holding great promise for future practical applications.

关键词： Fe2O3 Mesoporous carbon Yolk@shell Lithium ion battery

Novel fabrication techniques for ultra-thin silicon based flexible electronics

在线全文

学校读者我要写书评

暂无评论

International Journal of extreme Manufacturing 2024年第4期6卷 116-149页

作者： Ju Young Lee Jeong Eun Ju Chanwoo Lee Sang Min Won Ki Jun Yu School of Electrical and Electronic Engineering Yonsei University50 Yonsei-roSeodaemunguSeoul 03722Republic of Korea Department of Electrical and Computer Engineering Sungkyunkwan UniversitySuwon 16419Republic of Korea YU-Korea institute of Science and Technology(KIST)institute Yonsei University50Yonsei-roSeodaemun-guSeoul 03722Republic of Korea

Flexible electronics offer a multitude of advantages,such as flexibility,lightweight property,portability,and high *** unique properties allow for seamless applications to curved and soft surfaces,leading to extensive utilization across a wide range of fields in consumer *** applications,for example,span integrated circuits,solar cells,batteries,wearable devices,bio-implants,soft robotics,and biomimetic ***,flexible electronic devices have been developed using a variety of materials such as organic,carbon-based,and inorganic semiconducting ***(Si)owing to its mature fabrication process,excellent electrical,optical,thermal properties,and cost efficiency,remains a compelling material choice for flexible ***,the research on ultra-thin Si in the context of flexible electronics is studied rigorously *** thinning of Si is crucially important for flexible electronics as it reduces its bending stiffness and the resultant bending strain,thereby enhancing flexibility while preserving its exceptional *** review provides a comprehensive overview of the recent efforts in the fabrication techniques for forming ultra-thin Si using top-down and bottom-up approaches and explores their utilization in flexible electronics and their applications.

关键词： flexible electronics silicon fabrication technique top-down approach bottom-up approach

Hetero-deformation promoted strengthening and toughening in BCC rich eutectic and near eutectic high entropy alloys

在线全文

学校读者我要写书评

暂无评论

Journal of materials Science & Technology 2023年第15期146卷 1-9页

作者： D.H.Chung J.Lee Q.F.He Y.K.Kim K.R.Lim H.S.Kim Y.Yang Y.S.Na Department of Special Alloys Extreme Materials Research InstituteKorea Institute of Materials ScienceChangwonThe Republic of Korea Department of Mechanical Engineering City University of Hong KongKowloon TongKowloonHong KongChina Graduate institute of Ferrous Technology Pohang University of Science and TechnologyPohangThe Republic of Korea Center for Heterogenic Metal Additive Manufacturing Pohang University of Science and TechnologyPohangThe Republic of Korea Department of materials Science and Engineering City University of Hong KongKowloon TongKowloonHong KongChina

Heterostructured eutectic high-entropy alloys(EHEAs)have attracted significant attention owing to their novel properties,such as balanced combinations of strength and fracture ***,the toughening/strengthening mechanisms of these EHEAs have not been thoroughly *** this study,we developed a series of dual-phase Al_((18–2x))Co_(30)Cr_((11+x))Fe_((11+x))Ni_(3)0(x=-1,0,1)eutectic and neareutectic HEAs containing face-centered cubic(FCC)and body-centered cubic(BCC)*** the high amount of BCC,which is referred to as the brittle phase,newly developed EHEAs exhibited superior fracture ***,we discovered that a fully eutectic HEA exhibited further improvements in both yield stress and fracture toughness,outperforming our off-eutectic and other previously reported *** combining experiments and theoretical models,we demonstrated that the synergistic increase in both strength and toughness in our fully eutectic HEA was derived from the high hetero-deformationinduced(HDI)strengthening/toughening associated with a high misorientation angle at the grain/phase boundaries.

关键词： Eutectic high entropy alloy Fracture toughness Heterogeneous structure Hetero deformation induced strengthening Misorientation angle

An index for deformation controllability of small-volume materials

维普期刊数据库评论

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(Technological Sciences) 2014年第4期57卷 663-670页

作者： WANG ZhangJie SHAN ZhiWei LI Ju SUN Jun MA Evan Center for Advancing materials Performance from the Nanoscale CAMP-Nano) & Hysitron Applied Research Center in China (HARCC) State Key Laboratory for Mechanical Behavior of Materials Xi'an Jiaotong University Department of Nuclear Science and Engineering and Department of materials Science and Engineering Massachusetts Institute of Technology Department of materials Science and Engineering Johns Hopkins University

Mechanical tests on small-volume materials show that in addition to the usual attributes of strength and ductility, the controlla- bility of deformation would be crucial for the purpose of precise plastic shaping. In our present work, a ＂mechanical controlla- bility index＂（MCI） has been proposed to assess the controllability of mechanical deformation quantitatively. The index allows quantitative evaluation of the relative fraction of the controllable plastic strain out of the total strain. MCI=0 means completely uncontrollable plastic deformation, MCI=∞ means perfectly controllable plastic shaping. The application of the index is demonstrated here by comparing two example cases： 0.273 to 0.429 for single crystal A1 nanopillars that exhibit obvious strain bursts, versus 3.17 to 4.2 for polycrystalline A1 nanopillars of similar size for which the stress-strain curve is smoother.

关键词： mechanical controllability index plastic deformation strain bursts nanomechanics

Dissipative Kerr solitons in optical microresonators with Raman effect and third-order dispersion

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2021年第5期30卷 395-400页

作者： Chaohua Wu Zhiwei Fang Jintao Fan Gang Chen Ya Cheng State Key Laboratory of Quantum Optics and Quantum Optics Devices Institute of Laser SpectroscopyShanxi UniversityTaiyuan 030006China Collaborative Innovation Center of extreme Optics Shanxi UniversityTaiyuan 030006China The extreme Optoelectromechanics Laboratory(XXL) School of Physics and Materials ScienceEast China Normal UniversityShanghai 200241China Collaborative Innovation Center of Light Manipulations and Applications Shandong Normal UniversityJinan 250358China

Using the mean-field normalized Lugiato-Lefever equation,we theoretically investigate the dynamics of cavity soliton and comb generation in the presence of Raman effect and the third-order *** of them can induce the temporal drift and frequency *** on the moment analysis method,we analytically obtain the temporal and frequency shift,and the results agree with the direct numerical ***,the compensation and enhancement of the soliton spectral between the Raman-induced self-frequency shift and soliton recoil are *** results pave the way for further understanding the soliton dynamics and spectral characteristics,and providing an effective route to manipulate frequency comb.

关键词： dissipative Kerr soliton frequency comb Raman effect dispersive wave