检索结果-南通市图书馆

Anomalous low-temperature heat capacity in antiperovskite compounds

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2017年第2期26卷 370-374页

作者： Xin-Ge Guo[l,2] Jian-Chao Lin Peng Tong Shuai Lin Cheng Yang wen-Jian Lu wen-hai song Yu-Ping Sun Key Laboratory of Materials Physics Institute of Solid State Physics Chinese Academy of Sciences Hefei 230031 China University of Science and Technology of China Hefei 230026 China High Magnetic FieM Laboratory Chinese Academy of Sciences Hefei 230031 China Collaborative Innovation Center of Advanced Microstructures Nanjing University Nanjing 210093 China

The low-temperature heat capacities are studied for antiperovskite compounds AX M_3（A = Al, Ga, Cu, Ag, Sn, X = C,N, M = Mn, Fe, Co）. A large peak in（C- γ T）/T^3 versus T is observed for each of a total of 18 compounds investigated,indicating an existence of low-energy phonon mode unexpected by Debye T^3 law. Such a peak is insensitive to the external magnetic field up to 80 k Oe（1 Oe = 79.5775 A·m-1）. For compounds with smaller lattice constant, the peak shifts towards higher temperatures with a reduction of peak height. This abnormal peak in（C- γ T）/T^3 versus T of antiperovskite compound may result from the strongly dispersive acoustic branch due to the heavier A atoms and the optical-like mode from the dynamic rotation of X M_6 octahedron. Such a low-energy phonon mode may not contribute negatively to the normal thermal expansion in AX M_3 compounds, while it is usually concomitant with negative thermal expansion in open-structure material（e.g., ZrW_2O_8, Sc F_3）.

关键词： low-temperature heat capacity low-energy phonon modes antiperovskite compound negative thermal expansion

Nonvolatile Resistive Switching and Physical Mechanism in LaCrO3 Thin Films

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2018年第4期35卷 98-102页

作者： Wan-Jing Hu Ling Hu Ren-Huai Wei Xian-Wu Tang wen-hai song Jian-Ming Dai Xue-Bin Zhu Yu-Ping Sun Key Laboratory of Materials Physics Institute of Solid State Physics Chinese Academy of Sciences Hefei 230031 University of Science and Technology of China Hefei 230026 High Magnetic Field Laboratory Chinese Academy of Sciences Hefei 230031 Collaborative Innovation Center of Advanced Microstructufes Nanjing University Nanjing 210093

Polycrystalline LaCrO3（LCO） thin films are deposited on Pt/Ti/SiO2/Si substrates by pulsed laser deposition and used as the switching material to construct resistive random access memory devices. The unipolar resistive switching（RS） behavior in the Au/LCO/Pt devices exhibits a high resistance ratio of ~104 between the high resistance state（HRS） and low resistance state（LRS） and exhibits excellent endurance/retention *** conduction mechanism of the HRS in the high voltage range is dominated by the Schottky emission, while the Ohmic conduction dictates the LRS and the low voltage range of HRS. The RS behavior in the Au/LCO/Pt devices can be understood by the formation and rupture of conducting filaments consisting of oxygen vacancies,which is validated by the temperature dependence of resistance and x-ray photoelectron spectroscopy *** analysis shows that the reset current IR and reset power PR in the reset processes exhibit a scaling law with the resistance in LRS（R0）, which indicates that the Joule heating effect plays an essential role in the RS behavior of the Au/LCO/Pt devices.

关键词： La Cr HRS LRS Pt Nonvolatile Resistive Switching and Physical Mechanism in LaCrO3 Thin Films

Concurrent Structural and Electronic Phase Transitions in V_(2)O_(3)Thin Films with Sharp Resistivity Change

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2021年第7期38卷 79-84页

作者： Chuang Xie Ling Hu Ran-Ran Zhang Shun-Jin Zhu Min Zhu Ren-Huai Wei Xian-Wu Tang wen-hai song Xue-Bin Zhu Yu-Ping Sun Institutes of Physical Science and Information Technology Anhui UniversityHefei 230601China Key Laboratory of Materials Physics Institute of Solid State PhysicsHFIPSChinese Academy of SciencesHefei 230031China High Magnetic Field Laboratory HFIPSChinese Academy of SciencesHefei 230031China Collaborative Innovation Center of Advanced Microstructures Nanjing 210093China

The relationship between structural and electronic phase transitions in V_(2)O_(3)thin films is of critical importance for understanding of the mechanism behind metal–insulator transition(MIT)and related technological *** being extensively studied,there are currently no clear consensus and picture of the relation between structural and electronic phase transitions so *** V_(2)O_(3)thin films grown on r-plane Al2O3 substrates,which exhibit abrupt MIT and structural phase transition,we show that the electronic phase transition occurs concurrently with the structural phase transition as revealed by the electrical transport and Raman spectra *** result provides experimental evidence for clarifying this issue,which could form the basis of theoretical studies as well as technological applications in V_(2)O_(3).

关键词： structural transition Transition

Epitaxial Bi_(2)Sr_(2)CuO_(y) thin films as p-type transparent conductors

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2022年第10期31卷 514-519页

作者： Chen Zhou Wang-Ping Cheng Yuan-Di He Cheng Shao Ling Hu Ren-Huai Wei Jing-Gang Qin wen-hai song Xue-Bin Zhu Chuan-Bing Cai Yu-Ping Sun Key Laboratory of Materials Physics Institute of Solid State PhysicsHFIPSChinese Academy of SciencesHefei 230031China University of Science and Technology of China Hefei 230026China Institute of Plasma Physics Chinese Academy of SciencesHFIPSChinese Academy of SciencesHefei 230031China Physics Department Shanghai Key Laboratory of High Temperature SuperconductorsShanghai UniversityShanghai 200444China High Magnetic Field Laboratory HFIPSChinese Academy of SciencesHefei 230031China Collaborative Innovation Centre of Advanced Microstructures Nanjing UniversityNanjing 210093China

Development of p-type transparent conducting thin films is tireless due to the trade-off issue between optical transparency and conductivity. The rarely concerned low normal state resistance makes Bi-based superconducting cuprates the potential hole-type transparent conductors, which have been realized in Bi_(2)Sr_(2)CaCu_(2)O_(y) thin films. In this study, epitaxial superconducting Bi_(2)Sr_(2)CuO_(y) and Bi_(2)Sr_(1.8)Nd_(0.2)CuO_(y) thin films with superior normal state conductivity are proposed as ptype transparent conductors. It is found that the Bi_(2)Sr_(1.8)Nd_(0.2)CuO_(y) thin film with thickness 15 nm shows an average visible transmittance of 65% and room-temperature sheet resistance of 650 Ω/sq. The results further demonstrate that Bi-based cuprate superconductors can be regarded as potential p-type transparent conductors for future optoelectronic applications.

关键词： p-type transparent conductor sol-gel Bi-2201

500kV架空输电线路张力架线施工质量控制

在线全文

学校读者我要写书评

暂无评论

电力系统装备 2019年第21期 45-46页

作者：温海松广东电网能源发展有限公司广东广州510160

高压架空输电线路敷设工程中,张力架线施工技术为不能缺少的一项内容,这一工程技术的应用范围甚广。对于整个路线的安全运行来说,张力架线施工技术质量水平能够形成严重的影响。因此,应有效地控制施工质量,提升高压张力架线的整体质量... 详细信息

高压架空输电线路敷设工程中,张力架线施工技术为不能缺少的一项内容,这一工程技术的应用范围甚广。对于整个路线的安全运行来说,张力架线施工技术质量水平能够形成严重的影响。因此,应有效地控制施工质量,提升高压张力架线的整体质量。本文主要是分析500 kV架空输电线路张力架线施工质量控制相关内容,以期辅助相关的课题研究。

关键词： 500 kV 架空输电线路张力架线施工质量控制策略

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

铜闪速吹炼过程多相平衡热力学分析

中国有色金属学报 2017年第7期27卷 1493-1503页

作者：李明周周孑民张文海李贺松童长仁中南大学冶金与环境学院长沙410083 江西理工大学冶金与化学工程学院赣州341000 中南大学能源科学与工程学院长沙410083

基于最小自由能原理,建立铜闪速吹炼过程多相平衡数学模型,考察粗铜含硫(CSCu)、渣中钙铁比(RCaFe)、富氧浓度(COxy)和温度(T)对平衡产物各相主元素与组分含量的影响。结果表明:对一定投入量和一定成分的铜锍,提高CSCu可增加粗铜产能,... 详细信息

基于最小自由能原理,建立铜闪速吹炼过程多相平衡数学模型,考察粗铜含硫(CSCu)、渣中钙铁比(RCaFe)、富氧浓度(COxy)和温度(T)对平衡产物各相主元素与组分含量的影响。结果表明:对一定投入量和一定成分的铜锍,提高CSCu可增加粗铜产能,但Cu品位降低,可减少渣量,渣含Fe_3O_4降低,渣流动性变好;随着RCaFe增加,粗铜量减小,渣量和熔剂量增加,渣含FeO和Fe_3O_4降低,渣含Cu升高;COxy增加,除对粗铜含氧、富氧和烟气量产生一定影响外,对其他组分含量影响不大;T增加,会影响粗铜含氧、粗铜和炉渣量,还可降低渣含铜。

关键词：铜闪速吹炼最小吉布斯自由能多相平衡热力学

An efficient quantum proactive incremental learning algorithm

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 49-57页

作者： Lingxiao Li Jing Li Yanqi song Sujuan Qin Qiaoyan wen Fei Gao State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications School of Cyberspace Security Beijing University of Posts and Telecommunications

In scenarios where a large amount of data needs to be learned, incremental learning can make full use of old knowledge, significantly reduce the computational cost of the overall learning process, and maintain high performance. In this paper, taking the MaxCut problem as our example, we introduce the idea of incremental learning into quantum computing, and propose a Quantum Proactive Incremental Learning algorithm(QPIL). Instead of a one-off training of quantum circuit, QPIL contains a multi-phase training on gradually-increased subgraphs of all vertices, proactively reducing large-scale problems to smaller ones to solve in steps, providing an efficient solution for MaxCut. Specifically, some vertices and corresponding edges are randomly selected for training to obtain optimized parameters of the quantum circuit at first. Then, in each incremental phase, the remaining vertices and corresponding edges are gradually added and the parameters obtained from the previous phase are reused in the parameter initialization of the current phase. We perform experiments on 120 different small-scale graphs, and it shows that QPIL performs superior to prevalent quantum and classical baselines in terms of approximation ratio(AR), time cost, anti-forgetting, and solving stability. In particular, QPIL's AR surpasses 20% of mainstream quantum baselines, and the time cost is less than 1/5 of them. The idea of QPIL is expected to inspire efficient and high-quality solutions in large-scale Max Cut and other combinatorial optimization problems.

关键词： variational quantum algorithm incremental learning multi-phase training MaxCut quantum computing

Subtle lattice distortion-driven phase transitions in layered ACu_(4)As_(2)(A=Eu,Sr)

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2023年第10期32卷 561-565页

作者：聂勇陈正梅明王园园吴嘉挺蒋佳良宋文海宁伟王钊胜朱相德田明亮 Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions High Magnetic Field LaboratoryHefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031China Department of Physics University of Science and Technology of ChinaHefei 230026China Key Laboratory of Materials Physics Institute of Solid State PhysicsHFIPSChinese Academy of SciencesHefei 230031China School of Physics Anhui UniversityHefei 230601China

The compounds composed of transition metal cations and pnictide anions provide a rich platform for studying novel physical *** we report on the observation of a phase transition at~70 K and 145 K in layered compound EuCu_(4)As_(2)and SrCu_(4)As_(2),*** both the transport and heat *** thermal expansion measurements show that the variation of the lattice parameters(△L_(b)/L_(ab))around T_(P) is much less than that for a typical crystalline phase *** experimental results reveal that the transition in EuCu_(4)As_(2)and SrCu_(4)As_(2)should be driven by subtle structural-distortion.

关键词： thermal expansion specific heat lattice-distortion

Effects of aggregate size distribution and carbon nanotubes on the mechanical properties of cemented gangue backfill samples under true triaxial compression

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 311-324页

作者： Qian Yin Fan wen Zhigang Tao hai Pu Tianci Deng Yaoyao Meng Qingbin Meng Hongwen Jing Bo Meng Jiangyu Wu State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering China University of Mining and TechnologyXuzhou 221116China State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines Anhui University of Science and TechnologyHuainan 232001China State Key Laboratory for Geomechanics&Deep Underground Engineering China University of Mining and Technology(Beijing)Beijing 100083China Key Laboratory of Xinjiang Coal Resources Green Mining Ministry of EducationXinjiang Institute of EngineeringUrumqi 830023China

The mechanical behavior of cemented gangue backfill materials(CGBMs)is closely related to particle size distribution(PSD)of aggregates and properties of cementitious ***,the true triaxial compression tests,CT scanning,SEM,and EDS tests were conducted on cemented gangue backfill samples(CGBSs)with various carbon nanotube concentrations(P_(CNT))that satisfied fractal theory for the PSD of *** mechanical properties,energy dissipations,and failure mechanisms of the CGBSs under true triaxial compression were systematically *** results indicate that appropriate carbon nanotubes(CNTs)effectively enhance the mechanical properties and energy dissipations of CGBSs through micropore filling and microcrack bridging,and the optimal effect appears at P_(CNT)of 0.08wt%.Taking PSD fractal dimension(D)of 2.500 as an example,compared to that of CGBS without CNT,the peak strength(σ_(p)),axial peak strain(ε_(1,p)),elastic strain energy(Ue),and dissipated energy(U_(d))increased by 12.76%,29.60%,19.05%,and90.39%,***,excessive CNTs can reduce the mechanical properties of CGBSs due to CNT agglomeration,manifesting a decrease inρ_(p),ε_(1,p),and the volumetric strain increment(Δε_(v))when P_(CNT)increases from 0.08wt%to 0.12wt%.Moreover,the addition of CNTs improved the integrity of CGBS after macroscopic failure,and crack extension in CGBSs appeared in two modes:detour and pass through the ***σ_(p)and U_(d)firstly increase and then decrease with increasing D,and porosity shows the opposite ***ε_(1,p)andΔε_(v)are negatively correlated with D,and CGBS with D=2.150 has the maximum deformation parameters(ε_(1,p)=0.05079,Δε_(v)=0.01990)due to the frictional slip effect caused by coarse *** increasing D,the failure modes of CGBSs are sequentially manifested as oblique shear failure,"Y-shaped"shear failure,and conjugate shear failure.

关键词： cemented gangue backfill materials particle size distribution true triaxial compression test carbon nanotubes mechanical properties failure modes