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Wear of semi-solid rheocast SiC_p/Al metal matrix composites

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中国有色金属学会会刊：英文版 2010年第S3期20卷 852-856页

作者： u.A.CuRlE l.IVANCHEV Materials Science and Manufacturing Council for Scientific and Industrial Research(South Africa)

Rheocasting of plates in Al alloy 359 reinforced with SiC at 11%,27% and 50%(volume fractions) exhibits the capability of the council for scientific and industrial research-rheocasting system(CSIR-RCS) in rheo-processing and high pressure die casting of SiC metal matrix *** metal matrix consisting of nearly spherical proeutectic α(Al) globules was *** of fibrous eutectic silicon took place upon heat treatment of the as-cast metal matrix composites(MMCs).Hardness increases as the volume fractions of SiC *** rates of the MMCs in the F and T6 heat treatment conditions were assessed with a metallographic preparation *** is found that the 11% SiC MMC wear rate is higher on SiC abrasives compared with the 50% SiC MMC wear rate due to wear of the aluminum *** trend is reversed on diamond abrasives due to pull-out of the irregular shaped composite *** 50% SiC MMC suffers from composite particle fracture porosity after high pressure die casting(HPDC).

关键词： CSIR-RCS HPDC SiC F condition T6 condition wear rate hardness porosity

On the detection of closed orbits in time-dependent systems by using double-pulse lasers

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Communications in Theoretical Physics 2020年第9期72卷 111-117页

作者： S u Khan M l Du Institute of Theoretical Physics Chinese Academy of Sciences.Beijing 100190China university of Chinese Academy of Sciences Beijing100049China

In the photodetachment of atoms or negative ions by a double-pulse laser, the first pulse of the double-pulse laser generates waves and the delayed second pulse may detect them. The phenomenon of the excitation and detection of waves by a double-pulse laser can be used to identify the closed orbits in the system. We demonstrate this phenomenon with a negative hydrogen ion(H^-) by analyzing the total population excited by a double-pulse laser in a timedependent field for different physical parameters. By analyzing the total excited population using a double-pulse laser, we can uncover all the closed orbits existing in the system. We demonstrate that this can be realized by scanning the first pulse position and the time delay between the two pulses.

关键词： double-pulse laser detection of closed orbits photodetachment spectra time-dependent systems

Effect of densification distribution on the Young's modulus of porous coatings after nano-indentation

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Acta Metallurgica Sinica(English letters) 2012年第5期25卷 383-390页

作者： Xiaojuan l u Ping XIAO Haiyan lI School of Environment Science and Engineering North China Electric Power University Yonghua North Street Baoding 071000 China School of Materials The University of Manchester Manchester M1 7HS UK School of Mechanical Aerospace and Civil Engineering The University of Manchester P.O. Box 88Sackville Street Manchester M60 1QD UK

Nano-indentation of a porous ceramic coating leads to crushing and densification of the coating under the indenter. In this work, finite element simulations of indentation on the porous coating have been carried out to study the effect of the size and dis- tribution of densification on Youngts modulus measured by nano-indentation. Two totally different distribution patterns have been simulated in this work. In the case of gradient densification, the Youngts modulus increased by 8.6% when the densifi- cation has occurred in the maximum influenced area. While the Young^s modulus increased by 2% with a uniformed densification. Examinations of the cross-section of the coatings have suggested that the densification after the indentation is close to the second model. The measured Young＇s modulus could have differed by 2%. The effect of densification on the Young＇s modulus measured by using nano-indentation is strongly dependent on the densification patterns of the porous coating.

关键词： Film Mechanical property Finite element simulation Porosity Electron Microscopy

Focal distance tabu search

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Science China(Information Sciences) 2021年第5期64卷 5-16页

作者： Fred GlOVER Zhipeng lü Meta-Analytics Inc. School of Computer Science and Technology Huazhong University of Science and Technology

Focal distance tabu search modifies a standard tabu search algorithm for binary optimization by augmenting a periodic diversification step that drives the search away from a current best(or elite) solution until the objective function deteriorates beyond a specified threshold or until attaining a lower bound on the distance from the originating solution. The new augmented algorithm combines the threshold and lower bound approaches by introducing an initial focal distance for the lower bound which is updated when the diversification step is completed. However, rather than terminating the diversification step at the customary completion point, focal distance tabu search(TS) retains the focal distance bound through additional search phases designed to improve the objective function, drawing on a strategy proposed with strategic *** algorithm realizes this strategy by partitioning the variables into two sets which are managed together with an abbreviated tabu search process. An advanced version of the approach drives the search away from a collection of solutions rather than a single originating solution, introducing the concept of a signature solution to guide the search. The method can be employed to augment a variety of other metaheuristic algorithms such as those using threshold procedures, late acceptance hill climbing, iterated local search, breakout local search, GRASP, and path relinking.

关键词： tabu search diversification strategic oscillation adaptive partitioning metaheuristics

Variational data encoding and correlations in quantum-enhanced machine learning

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Chinese Physics B 2024年第9期33卷 298-306页

作者： Ming-Hao Wang Hua l¨u School of Physics Hubei UniversityWuhan 430062China School of Science Hubei University of TechnologyWuhan 430068China

leveraging the extraordinary phenomena of quantum superposition and quantum correlation,quantum computing offers unprecedented potential for addressing challenges beyond the reach of classical *** paper tackles two pivotal challenges in the realm of quantum computing:firstly,the development of an effective encoding protocol for translating classical data into quantum states,a critical step for any quantum *** encoding strategies can significantly influence quantum computer ***,we address the need to counteract the inevitable noise that can hinder quantum *** primary contribution is the introduction of a novel variational data encoding method,grounded in quantum regression algorithm *** adapting the learning concept from machine learning,we render data encoding a learnable *** allowed us to study the role of quantum correlation in data *** numerical simulations of various regression tasks,we demonstrate the efficacy of our variational data encoding,particularly post-learning from instructional ***,we delve into the role of quantum correlation in enhancing task performance,especially in noisy *** findings underscore the critical role of quantum correlation in not only bolstering performance but also in mitigating noise interference,thus advancing the frontier of quantum computing.

关键词： quantum machine learning variational data encoding quantum correlation

Effects of slag fineness on durability of mortars

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Journal of Zhejiang university-Science A(Applied Physics & Engineering) 2007年第11期8卷 1725-1730页

作者： TOPu lker Bekir BlR Turhan Department of Civil Engineering Eski■ehir Osmangazi university Eski■ehir 26480 Turkey

In recent years, the usages of by-products and wastes in industry have become more important. The importance of the sustainable development is also of increasing. The utilizations of wastes, as mineral admixture or fine aggregate, reduce the consumption of the natural resources and improve the durability of concrete. In this study, the effect of the fineness on the high temperature and sulphate resistances of concrete mortar specimens, produced with ground granulated blast-furnace slag (GBFS) replacing cement, is investigated. The compressive and flexural strength test results for all series related to durability effects, exposing temperature and solutions, exposure times for these durability effects, slag content and fineness are discussed. Conse- quently, the optimum slag contents are determined for producing the sulphate and high temperature resistant mortars.

关键词： Cement Fineness Ground slag High temperature effect Sulphate attack Sustainable development

Simulation of rainfall-runoff and watershed convergence process in the upper reaches of Heihe River Basin,July 2002

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Science China Earth Sciences 2004年第Z1期47卷 1-8页

作者： GAO Yanhong l(u) Shihua CHENG Guodong Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China

The watershed flow concentration scheme in the distributed hydrology-soil- vegetation model (DHSVM) is coupled with the mesoscale atmospheric model MM5 version 3.5, in which the Oregen States university land surface model (OSulSM) was involved. The flood event which happened in July 2002 in the upper reaches of Heihe river basin is simulated and the surface flow convergence process is shown with this coupled model. It has been concluded that times water head reaches each place of the basin are different. Water amount at each point is split-flow proportionally as the drops in elevation between it and neighbor points. large part of the water amount pass away in greater slope direction and small part pass away in smaller slope *** of the slope convergence makes the atmospheric model redistributes the surface water laterally.

关键词： distributed hydrology-soil-vegetation model, mesoscale atmospheric model, watershed flow concentration process.

RATIONAl GENERAl SOluTIONS OF HIGHER ORDER AlGEBRAIC ODES

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Journal of Systems Science & Complexity 2013年第2期26卷 261-280页

作者： HuANG Yanli NG l X Chu WINKlER Franz School of Computer Science and Software Engineering Tianjin Polytechnic University Research Institute for Symbolic Computation(RISC) Johannes Kepler University Department of Mathematics Quy Nhon University

This paper generalizes the method of Ng6 and Winkler （2010, 2011） for finding rational general solutions of a first order non-autonomous algebraic ordinary differential equation （AODE） to the case of a higher order AODE, provided a proper parametrization of its solution hypersurface. The authors reduce the problem of finding the rational general solution of a higher order AODE to finding the rational general solution of an associated system. The rational general solutions of the original AODE and its associated system are in computable 1-1 correspondence. The authors give necessary and sufficient conditions for the associated system to have a rational solution based on proper reparametrization of invariant algebraic space curves. The authors also relate invariant space curves to first integrals and characterize rationally solvable systems by rational first integrals.

关键词： Algebraic ODE associated system invariant algebraic space curve rational first integral rational general solution.

Null Controllability for Some Systems of Two Backward Stochastic Heat Equations with One Control Force

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Chinese Annals of Mathematics,Series B 2012年第6期33卷 909-918页

作者： Hongheng lI Qi lÜ College of Mathematics and Information Science Leshan Normal University School of Mathematical Sciences University of Electronic Science and Technology of China Basque Center for Applied Mathematics Mazarredo 14 48009BilbaoBasque CountrySpain.

Abstract The authors establish the null controllability for some systems coupled by two backward stochastic heat equations. The desired controllability result is obtained by means of proving a suitable observability e... 详细信息

关键词： Backward stochastic heat equation, Null controllability Observabilityestimate