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Dynamics of momentum distribution and structure factor in a weakly interacting Bose gas with a periodical modulation

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communications in Theoretical Physics 2020年第12期72卷 171-175页

作者： Ning Liu z c tu Department of Physics Beijing Normal UniversityBeijing 100875China

The momentum distribution and dynamical structure factor in a weakly interacting Bose gas with a time-dependent periodic modulation in terms of the Bogoliubov treatment are *** evolution equation related to the Bogoliubov weights happens to be a solvable Mathieu equation when the coupling strength is periodically *** exact relation between the time derivatives of momentum distribution and dynamical structure factor is derived,which indicates that the single-particle property is strongly related to the two-body property in the evolutions of Bose–Einstein *** is found that the momentum distribution and dynamical structure factor cannot display periodical *** stable dynamics,some particular peaks in the curves of momentum distribution and dynamical structure factor appear synchronously,which is consistent with the derivative relation.

关键词： Bose gas periodical coupling constant dynamical structure factor Mathieu equation

Deep Learning Quantum States for Hamiltonian Estimation

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chinese Physics Letters 2021年第11期38卷 1-6页

作者： Xinran Ma z.c.tu Shi-Ju Ran Department of Physics Beijing Normal UniversityBeijing 100875China Department of Physics Capital Normal UniversityBeijing 100048China

Human experts cannot efficiently access physical information of a quantum many-body states by simply "reading"its coefficients, but have to reply on the previous knowledge such as order parameters and quantum *** demonstrate that convolutional neural network(cNN) can learn from coefficients of many-body states or reduced density matrices to estimate the physical parameters of the interacting Hamiltonians, such as coupling strengths and magnetic fields, provided the states as the ground states. We propose QubismNet that consists of two main parts: the Qubism map that visualizes the ground states(or the purified reduced density matrices) as images, and a cNN that maps the images to the target physical parameters. By assuming certain constraints on the training set for the sake of balance, QubismNet exhibits impressive powers of learning and generalization on several quantum spin models. While the training samples are restricted to the states from certain ranges of the parameters, QubismNet can accurately estimate the parameters of the states beyond such training regions. For instance, our results show that QubismNet can estimate the magnetic fields near the critical point by learning from the states away from the critical vicinity. Our work provides a data-driven way to infer the Hamiltonians that give the designed ground states, and therefore would benefit the existing and future generations of quantum technologies such as Hamiltonian-based quantum simulations and state tomography.

关键词： cNN MSE RDM image Hamiltonian Deep Learning Quantum States for Hamiltonian Estimation Quantum

Initial-state dependence of phase behaviors in a dense active system

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chinese Physics B 2023年第8期32卷 355-360页

作者：陈璐张博凯涂展春 Department of Physics Beijing Normal UniversityBeijing 100875China complex Systems Division Beijing Computational Science Research CenterBeijing 100193China School of Physical Science and Technology Southwest UniversityChongqing 400715China

There are rich emergent phase behaviors in non-equilibrium active *** and clustering are two representative dynamic *** relationship between both the phases is still ***,we numerically investigate the evolution of flocking and clustering in a system consisting of self-propelled particles with active *** consider the interplay between flocking and clustering phases with different initial configurations,and observe a domain in steady state order parameter phase diagrams sensitive to the choice of initial ***,by tuning the initial degree of polar ordering,either a more ordered flocking or a disordered clustering state can be observed in the steady *** results enlighten us to manipulate emergent behaviors and collective motions of an active system,and are qualitatively different from the emergence of a new bi-stable regime observed in aligned active particles due to an explicit attraction[New ***.14073033(2012)].

关键词： initial state flocking clustering active systems

EVALUATION OF THE TIME DEPENDENT FAILURE ASSESSMENT cURVES FOR 10crMo910 AND 316 SS AT 550℃

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Acta Metallurgica Sinica(English Letters) 2004年第4期17卷 443-449页

作者： F.z.Xuan S.D.tu z.D.Wang c.W.Ma School of Mechanical Engineering East China University of Science and Technology Shanghai 200237ChinaSchool of Mechanical Engineering East China University of Science and Technology Shanghai 200237ChinaSchool of Mechanical Engineering East China University of Science and Technology Shanghai 200237ChinaSchool of Mechanical Engineering East China University of Science and Technology Shanghai 200237China

10crMo910 and 316 stainless steel are widely adopted in high temperature structures of power generations, chemical processing plants and petroleum refineries. In this work, a total of 10000 hour tensile creep test on 16 specimens of such two materials was conducted at 550℃. On the basis of the experimental results, the isochronous stress-strain curves and time-dependent failure assessment curves of the two materials were given. Finally, the formulae of time dependent failure assessment curve for 10crMo910 and 316 stainless steel corresponding to long-term creep cases, which could be utilized in the high temperature defects assessment, were established. The procedure for defining the time-dependent failure assessment curves was also presented.

关键词： 10crMo910 316 stainless steel creep time-dependent failure assessment curve

ISOcHRONOUS STRESS-STRAIN cURVES OF LOW ALLOY STEEL cROSS-WELD-SPEcIMEN AT HIGH TEMPERAtuRE

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Acta Metallurgica Sinica(English Letters) 2004年第4期17卷 612-617页

作者： c.W.Ma F.z.Xuan z.D.Wang S.T.tu East china University of Science and Technology Shanghai 200237 ChinaEast China University of Science and Technology Shanghai 200237 ChinaEast China University of Science and Technology Shanghai 200237 ChinaEast China University of Science and Technology Shanghai 200237 China Nanjing University of Technology Nanjing 210009 China

In this work, a parametric approach is presented and utilized to determine the creep properties of weldments; then the model of creep strain for cross weld specimen is given. On the basis of the experimental results, attempt has been made to establish equations of the isochronous stress-strain for weld joint that can predict the function of loading and service time in use of the creep data of base metal and weld metal.

关键词： isochronous stress-strain curve creep deformation high temperature welded joint low alloy steel

Performance of Sacrificial Anodes in Reinforced concrete

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武汉理工大学学报 2010年第17期32卷 165-169页

作者： tu L Q DONG c WANG c J zHANG G z LEI Y F SHUI z H School of Materials Science and Engineering Wuhan University of TechnologyWuhan 430070China Wuhan Harbour Engineering Design & Research co. Ltd Wuhan 430071China Key Lab of Large-span Bridge construction Technology Minstry of CommunicationsWuhan 430071China zhejiang Province zhoushan Island Linking construction commanding Department Zhoushan 316032China

The electrochemical performance of the anodes was measured in the reinforced concrete test block in artificial sea water. Their chemical composition,metallographic structure and surface morphology were analyzed. It was found that concrete mix proportion and the covering layer thickness had an impact on the performance of sacrificial anodes. The thermal-sprayed zinc alloy anodes had a more negative corrosion potential and larger galvanic current than metallurgy ones in the same conditions. They had similar chemical composition. But metallographic structure showed that the structure of thermal-sprayed zinc alloy anodes was a loose porous. This structure had the catalytic effect on the andes electrochemical reactions and made the anodes the electrochemical exchange current density increase and the corrosion potential move to negative direction.

关键词： sacrificial anode reinforced concrete concrete mix proportion thermal-sprayed anodes electrochemical performance

Design and Pilot Programs of Marine Exposure Station of A Sea-crossing Bridge

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武汉理工大学学报 2010年第17期32卷 131-136页

作者： QIN M Q WANG c J tu L Q zHANG G z SUN T X Wuhan Harbour Engineering Design and Research co. Ltd. Wuhan 430071China Key Lab of Large-span Bridge construction Technology Ministry of CommunicationsWuhan 430071China zhejiang Province zhoushan Island Linking construction commanding Department Zhoushan 316032China School of Materials Science and Engineering Wuhan University of TechnologyWuhan 430070China

This paper presents the Location,the structural design as well as the anti-corrosion and the pilot programs of the marine exposure station of zhoushan Archipelago seas sea-crossing bridges. Subjected to the marine environment,the concrete structures in serve with different mixing proportions,cover thickness,additional anti-corrosion measures such as rust-preventing agent,coating,penetration crystalline waterproof material,silicone and permeable fabric were studied. Those results obtained provide important information for the maintenance of marine concrete and the structural design of sea-crossing bridges in the above sea area.

关键词： exposure station sea-crossing bridge marine concrete durability design

Two-dimensional pipe leakage through a line crack in water distribution systems

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Journal of zhejiang University-Science A(Applied Physics & Engineering) 2013年第5期14卷 371-376页

作者： Shuai GUO tu-qiao zHANG Wei-yun SHAO David z.zHU Yuan-yu DUAN college of civil Engineering and Architecture Zhejiang University Deptment of civil and Environmental Engineering University of AlbertaEdmontonABT6G 2W2Canada

In water distribution systems,water leakage from cracked water pipes is a major concern for water ***,the relationship between the leakage rate and the water pressure can be modeled by a power function developed from the orifice *** paper presents an approximate solution for the computation of the steady-state leakage rate through a longitudinal line crack of a water distribution pipe considering the surrounding soil *** derived solution agrees well with results of numerical *** with the traditional models,the new solution allows assessment of all the parameters that related with leakage including the pressure head inside the pipe,hydraulic conductivity,crack size and its position,and pipe size and its depth.

关键词： Leakage Pipe crack Soil Water distribution systems Water pipes

Non‐chromate conversion process for zinc coating with durable hydrophobicity and enhanced corrosion resistance

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Biosurface and Biotribology 2022年第3期8卷 266-277页

作者： J.Y.chen z.Y.Hu z.X.Li X.L.Wang c.D.Gu J.P.tu School of Materials Science and Engineering State Key Laboratory of Silicon MaterialsZhejiang UniversityHangzhouChina Key Laboratory of Advanced Materials and Applications for Batteries of zhejiang Province HangzhouChina zhejiang Ecological and Environmental Monitoring center HangzhouChina zhejiang Key Laboratory of Ecological and Environmental Monitoring Forewarning and Quality ControlHangzhouChina

A zn‐based coating with durable hydrophobicity and good corrosion resistance was formed on a mild steel substrate,which involves electroplating zn from a non‐aqueous electrolyte,followed by passivation in an oleic acid(OA)*** electrodeposited zn coatings were porous,which facilitated the formation of a chemical conversion layer of zn oleate(zO)during OA *** zn coating after passivation had a twolayer structure,which included an outer layer of zO with a thickness of~26μm and an inner layer of zn with a thickness of~6μ*** outer layer zO is a type of metal soap with a smooth surface and durable hydrophobicity,such that water droplets can easily slip off its *** testing and electrochemical measurements in 3.5 wt.%Nacl aqueous solution indicate that the zn coating after OA passivation exhibits outstanding anti‐corrosion properties compared with those exhibited by pure zn *** corrosion products and mechanism of the two‐layer coating were *** study shows that smooth metal oleate coatings can provide hydrophobicity and corrosion resistance simultaneously to mild steel substrates.

关键词： Anti‐corrosion Electrodeposition Hydrophobic coating Passivation zn oleate