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Comparative study on CO_2 corrosion behavior of N80,P110,X52 and 13Cr pipe lines in simulated stratum water

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Science china(Technological Sciences) 2010年第9期53卷 2342-2349页

作者： CAI YiDong1,GUO PengChao1,LIU DaMeng1,CHEN ShiYu2 & LIU JunLai3 1 School of Energy Resources,china university of Geosciences,beijing 100083,china 2 School of Materials Science and Engineering,university of Science and technology beijing,beijing 100083,china 3 School of Earth Sciences and Resources,china university of Geosciences,beijing 100083,china 1. School of Energy Resources China University of Geosciences Beijing 100083 China2. School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China3. School of Earth Sciences and Resources China University of Geosciences Beijing 100083 China

To better understand the carbon dioxide (CO2) corrosion behavior of carbon steel and its influence on petroleum development (including drilling,production and transportation) in the Daqing Oilfield,CO2 corrosion behaviors of N80,P110,X52 and 13Cr pipe lines in simulated solution at high temperature and high pressure condition are investigated by dynamic corrosion experiments,scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDS) *** show that the corrosion rate of all pipe lines increases quickly when CO2 partial pressure increases from 0.5 to 1.5 MPa,but it slows down when CO2 partial pressure further increases from 1.5 to 4.5 MPa,during which localized corrosion is *** the experimental temperature ranges from 60 to 120°C,localized corrosion *** corrosion rate of all pipe lines decreases sharply when the temperature changes from 60 to 100°C,and it becomes stable after the temperature is higher than 100°*** the flow rate is in the range of 0–1.5 m/s,the corrosion rate of sample X52 remains unchanged,but localized corrosion gradually becomes very serious when the flow rate further *** analyzing the corrosion product scales of sample 13Cr,some remarkable phenomena are *** the temperature range of 60–100°C,the corrosion product scales are loose and thick,but become very compact when the temperature increases above 100°*** the later case,localized corrosion is *** main components of the corrosion product scales are FeCO3 and Cr2O3.

关键词： CO2 corrosion pipe lines weight loss SEM EDS

Oxidation of O'-SiAlON-ZrO_2 Composite Ceramics

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Journal of university of Science and technology beijing 2001年第1期8卷 43-47页

作者： Xidong Wang , Hong Bao, Wenchao Li Metallurgy School, university of Science and technology beijing, beijing 100083, china Department of Metallurgy, East china university of Metallurgy Maan Shan 243002, china Univ Sci & Technol beijing Met Sch Beijing 100083 Peoples R China E china Univ Met Dept Met Maan Shan 243002 Peoples R China

The oxidation kinetics of O'-SiAlON-ZrO2 composite ceramics in the temperature range of 1373-1773K has been studied. The oxidation experiments with powder and plates of O'-SiAlON-ZrO2 composite ceramics in air have been carried out. The overall activation energy of oxidation reaction is 263.69 kJ/mol. The products and structures of O'-SiAlON-ZrO2 oxidation layer have been analysed by XRD (X-ray diffraction), SEM (scanning electron microscope) and AFM (atomic force microscope).

关键词： O '-SiAlON ZrO2 ceramics oxidation

Prediction of Enthalpies of Fusion for Divalent Rare Earth Halides Based on Modeling by Artificial Neural Networks and Pattern Recognition

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International Journal of Minerals,Metallurgy and Materials 1999年第1期13卷 24-26页

作者： Yimin Sun Zhiyu Qiao Minghong He(Applied Science School, university of Science & technology beijing, beijing 100083, china)(National Natural Science Foundation of china, beijing 100083, china) Applied Science School University of Science and Technology Beijing Beijing 100083 China National Natural Science Foundation of china Beijing 100083 China

The artificial neural network (ANN) and the pattern recognition were applied to study the correlation of enthalpies of fusion for divalent rare earth halides with their microstructural parameters,such as ionic radius and electronegativity. The model,represented by a back-propagation netal network, was trained with a 12 set of published data for divalent rare earth halides and then was used to predict the unknown ones. Also the criterion equations were ptesented to determine the enthalpies of fuSion for divalent rare earth halides using pattern recognition in mis work. The results from the model in ANN and criterion equations are in very good agreement with reference data.

关键词： BP neural network pattern recognition enthalpy of fusion divalent rare earth halides microstructural parameters

Current distribution and stability of LTS/HTS hybrid superconducting conductors

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Science china(Technological Sciences) 2010年第7期53卷 2000-2007页

作者： GUAN XiaoJin1,2, WANG YinShun1 & ZHOU WeiWei3 1 Key Laboratory of HV and EMC beijing, north china Electric Power university, beijing 102206, china 2 Department of Physics, Baoding university, Baoding 071000, china 3 Institute of Electrical Engineering, Chinese Academy of Sciences, beijing 100190, china 1. Key Laboratory of HV and EMC beijing North China Electric Power University Beijing 102206 China2. Department of Physics Baoding University Baoding 071000 China3. Institute of Electrical Engineering Chinese Academy of Sciences Beijing 100190 China

Current distribution and stability of a hybrid LTS/HTS superconductor, consisting of multifilamentary NbTi/Cu and Bi2223/Ag tapes, were numerically analyzed according to power-law models. The results showed that most of current passed through the LTS and the current increased in the HTS with temperature rise when the transport current was below the critical current of the hybrid conductor. The quench propagation velocity of the hybrid conductor was smaller but its minimum quench energy was larger than those of LTS conductors, indicating that the stability of the hybrid superconducting conductor was effectively improved and a high engineering current density was simultaneously achieved. Finally, a hybrid sample, made by soldering Bi2223/Ag tape onto NbTi/Cu conductor, was prepared and tested successfully at helium temperature. The experimental results qualitatively agreed with the simulated ones.

关键词： distribution hybrid conductor minimum quench energy quench propagation velocity n value stability

Mixed boundary conditions for piezoelectric plates

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Science china(Physics,Mechanics & Astronomy) 2009年第5期52卷 755-761页

作者： GAO Yang 1 ,XU SiPeng 2 &ZHAO BaoSheng 3 1College of Science,china Agricultural university,beijing 100083,china 2College of Engineering,Ocean university of china,Qingdao 266071,china 3 School of Mechanical Engineering,university of Science and technology of Liaoning,Anshan 114044,china College of Science China Agricultural University Beijing 100083 China College of Engineering Ocean University of China Qingdao 266071 China School of Mechanical Engineering University of Science and Technology of Liaoning Anshan 114044 China

For plate bending and stretching problems in piezoelectric materials,the reciprocal theorem and the general solution of piezoelasticity are applied in a novel way to obtain the appropriate mixed boundary conditions accurate to all order.A decay analysis technique is used to establish necessary conditions that the prescribed data on the edge of the plate must satisfy in order that it should generate a decaying state within the *** the case of axisymmetric bending and stretching of a circular plate,these decaying state conditions are obtained explicitly for the first time when the mixed conditions are imposed on the plate *** are then used for the correct formulation of boundary conditions for the interior solution.

关键词： boundary conditions piezoelectric plates mixed data bending problems stretching problems

Recommendation Method for Contrastive Enhancement of Neighborhood Information

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Computers, Materials & Continua 2024年第1期78卷 453-472页

作者： Hairong Wang beijing Zhou Lisi Zhang He Ma School of Computer Science and Engineering North Minzu UniversityNingxia750021China

Knowledge graph can assist in improving recommendation performance and is widely applied in various person-alized recommendation ***,existing knowledge-aware recommendation methods face challenges such as weak user-item interaction supervisory signals and noise in the knowledge *** tackle these issues,this paper proposes a neighbor information contrast-enhanced recommendation method by adding subtle noise to construct contrast views and employing contrastive learning to strengthen supervisory signals and reduce knowledge ***,first,this paper adopts heterogeneous propagation and knowledge-aware attention networks to obtain multi-order neighbor embedding of users and items,mining the high-order neighbor informa-tion of users and ***,in the neighbor information,this paper introduces weak noise following a uniform distribution to construct neighbor contrast views,effectively reducing the time overhead of view *** paper then performs contrastive learning between neighbor views to promote the uniformity of view information,adjusting the neighbor structure,and achieving the goal of reducing the knowledge noise in the knowledge ***,this paper introduces multi-task learning to mitigate the problem of weak supervisory *** validate the effectiveness of our method,experiments are conducted on theMovieLens-1M,MovieLens-20M,Book-Crossing,and Last-FM *** results showthat compared to the best baselines,our method shows significant improvements in AUC and F1.

关键词： Contrastive learning knowledge graph recommendation method

Boundary conditions for the bending of a piezoelectric beam

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Science china(Physics,Mechanics & Astronomy) 2008年第7期51卷 847-856页

作者： GAO Yang1, XU SiPeng2 & ZHAO BaoSheng3 1 College of Science, china Agricultural university, beijing 100083, china 2 College of Engineering, Ocean university of china, Qingdao 266071, china 3 School of Mechanical Engineering, university of Science and technology Liaoning, Anshan 114044, china 1. College of Science China Agricultural University Beijing 100083 China 2. College of Engineering Ocean University of China Qingdao 266071 China 3. School of Mechanical Engineering University of Science and Technology Liaoning Anshan 114044 China

For beam bending in transversely isotropic piezoelectric media, the reciprocal theorem and the general solution of piezoelasticity are applied in a novel way to obtain the appropriate stress and mixed boundary conditions accurate to all orders for the beam of general edge geometry and loadings. By generalizing the method developed by Gregory and Wan, a set of necessary conditions on the edge-data for the existence of a rapidly decaying solution is established. The prescribed edge-data of the beam must satisfy these conditions in order that they could generate a decaying state within the beam. When stress and mixed conditions are imposed on the beam edge, these decaying state conditions for the case of bending deformation of piezoelectric beam are derived explicitly. They are then used for the correct formulation of boundary conditions for the beam theory solution (or the interior solution). Besides, an analytical solution of elastic beam is formulated to verify validity of our boundary conditions. For the stress data, our boundary conditions coincide with those obtained in conventional forms of beam theories. More importantly, the appropriate boundary conditions with two sets of mixed edge-data are obtained for the first time.

关键词： boundary conditions beam bending piezoelectric media decaying states regular states

Thermodynamic properties and mixing thermodynamic parameters of binary homogeneous metallic melts

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Rare Metals 2003年第1期22卷 25-32页

作者： ZHANG ManMetallurgical Engineering School, university of Science and technology beijing, beijing 100083, china Metallurgical Engineering School University of Science and Technology Beijing 北京 100083

After the investigation on the thermodynamic properties and mixingthermodynamic parameters of binary homogeneous metallic melts involving compound, peritectic as wellas solid solution, it was found that the equations of mixing free energy DELTA G^m and excess freeenergy DELTA G^(XS) of them can he expressed by the following equations: DELTA G^m = SIGMA x [SIGMAN_i DELTA G_I^(THETA) + RT(SIGMA N_j ln N_j + SIGMA N_i ln N_i )] and DELTA G^(XS) = DELTA G^m -RT(a ln a + b ln b), respectively.

关键词： metallic melt mixing thermodynamic parameter coexistence theory activity mass action concentration

Study on Sulfide-melt Inclusions in Mantle Xenoliths of Xinchang, Zhejiang

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International Journal of Minerals,Metallurgy and Materials 2000年第1期14卷 5-9页

作者： Jiuhua Xu Xuelei Chu YulingXie Fenglei Bie Dayi Qian university of Science and technology beijing, beijing 100083, china china university of Geosciences, beijing 100083, china The Research Center of Mineral Resources Exploration, Chinese Academy Univ Sci & Technol beijing Beijing 100083 Peoples R China china Univ Geosci Beijing 100083 Peoples R China Chinese Acad Sci Res Ctr Mineral Resources Explorat Beijing 100101 Peoples R China Chinese Acad Sci Inst Geol Beijing 100029 Peoples R China

In minerals of mantle xenoliths captured within Tertiary alkali-basalt from Xinchang, Zhejiang province, china, many sulfidemelt inclusions were found by the observation of polished thin section. Electron microprobe analysis has been applied to detect the components of sulfide-melt inclusions. The result shows that the sulfide phases of inclusions are mainly pentlandite, and secondarily pyrrho- tite, The molar ratio of Ni to Fe, r_Ni,/r_Fe, of mineral phases in sulfide inclusions is related to olivine contents in host mantle xenoliths. The r_Ni/r_Ni, of sulfides from Xinchang samples has a possitive correlation to r_(Fe+Ni),/r_S. The r_(Fe+Ni),/r_S, becomes higher with the increasing of r_Ni/r_Fe In single sulfide-melt inclusions, r_Ni,/r_Fe, r_(Fe+Ni),/r, and Ni contents increase from the center to edge, reflecting a result of different cooling speed in an inclusion. A comparison between the data from Hannuoba, West Eifel of Germany and Nograd-Gomor of east Europe suggests that the composition of the inclusions is different for each area, which indicated that a regional differentiation of sulfide in mantle fluids.

关键词： mantle xenolith sulfide-melt inclusion electron microprobe analysis, Xinchang