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A metric normalization of tree edit distance

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Frontiers of Computer science 2011年第1期5卷 119-125页

作者： Yujian Li (1) liyujian@*** Zhang Chenguang (12) Beijing univ technol Coll Comp Sci & Technol Beijing 100124 Peoples R China Hainan univ Coll Informat Sci & Technol Haikou 570228 Peoples R China

Traditional normalized tree edit distances do not satisfy the triangle inequality. We present a metric normalization method for tree edit distance, which results in a new normalized tree edit distance fulfilling the triangle inequality, under the condition that the weight function is a metric over the set of elementary edit operations with all costs of insertions/deletions having the same weight. We prove that the new distance, in the range [0, 1], is a genuine metric as a simple function of the sizes of two ordered labeled trees and the tree edit distance between them, which can be directly computed through tree edit distance with the same complexity. Based on an efficient algorithm to represent digits as ordered labeled trees, we show that the normalized tree edit metric can provide slightly better results than other existing methods in handwritten digit recognition experiments using the approximating and eliminating search algorithm （AESA） algorithm.

关键词： metric normalization tree edit distance,triangle inequality approximating and eliminating searchalgorithm (AESA)

INFLUENCE OF MINERAL ADMIXTURES ON MECHANICAL PROPERTIES OF HIGH-PERFORMANCE CONCRETE

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Journal of Wuhan university of technology(Materials science) 1999年第2期14卷 1-7页

作者： Ma, Baoguo Li, Jinzong Peng, Jun Wuhan univ technol Coll Mat Sci & Technol Wuhan 430070 Peoples R China Hong Kong univ sci & technol Hong Kong Hong Kong

The improvements of the mechanical properties, including bulk density of fresh mixtures, elastic modulus, and compressive strengths of four high-performance concrete mixtures, made with the addition of fly ash, refined ground blast - furnace microslag (microslag) and silica fume are studied. The concrete mixtures were determined based on the dispersion testing results. The study indicates that the elastic modulus at 28 and 91 days, and compressive strengths of the concretes are improved a lot when fly ash and microslag by 25 percent by weight of cement are added into the mixtures individually. The improvement is especially evident when silica fume by 5 percent and fly ash by 25 percent by weight of cement are added together into the mixture, while the fresh concrete mixture keeps a good workability. Through the analysis of chemically combined water ratios of the four mixtures at various hydration ages, it is found that the addition of all these mineral mixtures are beneficial to the hydration process, especially, at later stages, which might be one of the reasons for the improvement of mechanical properties. (Author abstract) 4 Refs.

关键词： high-performance concrete mineral admixture mechanical properties

Influence of Mg and Ti on the microstructure and electrochemical performance of aluminum alloy sacrificial anodes

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Rare Metals 2009年第2期28卷 187-192页

作者： Ma Jingling Wen Jiuba Li Xudong Zhao Shengli Yan Yanfu Lanzhou univ technol Sch Mat Sci & Engn Lanzhou 730050 Peoples R China Henan univ sci & technol Sch Mat Sci & Engn Luoyang 471003 Peoples R China

The experiments focused on the influence of magnesium and titanium as additional alloying elements on the microstructure and electro-chemical behavior of Al-Zn-In sacrificial anodes. The electrochemical behavior of the aluminum sacrificial anode with 3 wt.% sodium chloride solution was studied by electrochemical impedance spectroscopy (EIS) tests. It was found that a microstructure with few precipitates and refined grains could be achieved by adding 1 wt.% Mg and 0.05 wt.% Ti to the Al-Zn-In alloy,resulting...

关键词： aluminum alloy sacrificial anode electrochemical performance microstructure

Thin-shell Structure and Reactivity of Nanostructured NiPdCe Particles

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Journal of Materials science & technology 1997年第3期13卷 215-218页

作者： Chen, KZ Zhang, ZK Cui, ZL Yang, DZ DALIAN univ technol DEPT MAT SCI & TECHNOLDALIAN 116024PEOPLES R CHINA

Nanostructured NiPdCe particles by are plasma method in Ar+H-2 atmosphere were characterized by TEM, HRTEM and XRD. The results show that nanostructured NiPdCe particles possess the special structure consisting of the thin-shell layer composed of a series of CeNi phases, Pd and CeO2 and the core composed of Ni and Pd. The thickness of the shell layer is 2 similar to 3 nm. The reactivity of nano-NiPdCe particles was measured in the gas-phase hydrogenation of toluene. The results show that nano-NiPdCe particles possess high reactivity above 325 degrees C and the product selectivity is 100%. The reactivity of nano-NiPdCe particles depends on the synergistic effects of CeNi phases, Ni and Pd as well as the hydrogen storage property.

关键词： Nanostructured materials

EFFECTS OF NH_4Cl ON THE INTERACTION BETWEEN POLY(ETHYLENE OXIDE) AND IONIC SURFACTANTS IN AQUEOUS SOLUTIONS

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Chinese Journal of Polymer science 2008年第1期26卷 31-37页

作者： Li, Jing Li, Hua-zhen Yang, Hai-yang Zhu, Ping-ping He, Ping-sheng univ sci & technol China Dept Polymer Sci & Engn Hefei 230026 Peoples R China

The interaction of poly(ethylene oxide)(PEO)with the ionic surfactants,sodium dodecylsulfate(SDS)and cetyltrimethylammonium chloride(CTAC)respectively,in aqueous solutions containing a certain concentration of NH_4Cl, is studied by the viscosity *** has been found that the ion-dipole interaction between PEO and ionic surfactants is changed considerably by the organic *** anionic suffactant of SDS,the addition of NH_4Cl into solution strengthens the interaction between PEO and the headgroup o...

关键词： Viscosity Ion-dipole interaction Non-ionic polymer Ionic surfactant NH_4Cl

Continuous unidirectional solidification of QAl9-4 Cu-Al alloy

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中国有色金属学会会刊：英文版 1999年第3期9卷 493-499页

作者： Chang Guowei(常国威) Yuan Junping(袁军平) Wang Zidong(王自东) Wu Chunjing(吴春京) Hu Hanqi(胡汉起) Miao Zhimin(苗治民) Beijing univ sci & technol Sch Mat Sci & Engn Beijing 100083 Peoples R China

A continuous unidirectional solidification equipment with the advantages of electric slag remelting, induction heating, continuous casting and unidirectional solidification was built to study the QAl9 4 Cu Al alloy. The results show that the electro slag induction continuous unidirectional solidification process can be used for the steady continuous unidirectional solidification of QAl9 4, and revitalizes the down pulling continuous unidirectional solidification process; that the temperature distribution in the mold wall reflects that of the molten metal in the mold, thus the temperature distribution in the mold wall can be used to control the electric slag induction continuous unidirectional solidification process; and that the mutual matching of the technological parameters is the key to stabilize the solidification process.

关键词： QAl9 4 Cu Al alloy continuous casting electro slag remelting unidirectional solidification

Hot Deformation and Modeling of Flow Stress for a Ti-containing HSLA Steel

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Journal of Materials science & technology 1998年第5期14卷 419-424页

作者： Xu, Yourong Hou, Dahua Wang, Deying Xu, W-Ping Shanghai univ sci & technol Sch Mat Sci & Engn Shanghai 201800 Peoples R China

Single stage and double-stage interrupted hot compression tests for simulating hot rolling have been carried out for a Ti-containing HSLA steel (10Ti). Physical simulation of hot rolling was in progress utilizing a Thermecmastor-Z simulator in 850-1150 degree C and strain rate of 0.1-60 s** minus **1. A model for residual strain ratio lambda was designed, and a model of flow stress considering residual strain has been obtained. The hot deformation behavior at various strain rate has also been studied. (Edited author abstract) 13 Refs.

关键词： Steel

Special issue： Development of renewable energy and smart grid

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Frontiers in Energy 2017年第2期11卷 105-118页

作者： Schwarz, Harald Cai, Xiaoshu Brandenburg univ technol Cottbus Senftenberg Cottbus Germany univ Shanghai sci & technol Grad Sch Shanghai Peoples R China univ Shanghai sci & technol Coll Power Engn Shanghai Peoples R China

Germany,as well as China,conducted a variety of activities in the past decade to reduce CO2 in national power supply and strived to move to more renewable *** to geological differences in both countries,Germany established very fast a huge number of decentralized generation units from wind energy and *** from a technical point of view,these types of generation are highly fluctuating and not easily able to follow the power demand in the system minute by minute.

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Sputtering Rates of Alloys in Glow Discharge

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Journal of Materials science & technology 1995年第4期11卷 295-298页

作者： REN, JS ZHANG, GS WANG, ZS ZHAO, JW SHANGHAI univ sci & technol SHANGHAI 200072PEOPLES R CHINA

The sputtering rates of alloys were investigated under constant Ar pressure and voltage supplied. The alloys studied in this work range from binary intermetallic alloys to ternary and quaternary alloys. It is revealed that the sputtering rates of alloy targets under steady states are q = 1/Sigma C-i/q(i)(0) where q is the sputtering rates of alloys, C-i the weight percentage of i-th component in the alloy, and q(i)(0) the sputtering rate of pure metal of i-th component.

关键词： Binary alloys