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A Comparative Study of Boron and Phosphorus Doping Effects in SiC: H Films Prepared by ECR-CVD

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Journal of Materials Science & technology 1998年第1期14卷 65-71页

作者： S.F. Yoon (School of Electrical and Electronic Engineering, Nanyang technological university, Nanyang Avenue,Singapore 639798, Rep. of Singapore) Nanyang technol univ Sch Elect & Elect Engn Singapore 639798 Singapore

Hydrogenated silicon carbide films (SiC:H) were deposited using the electron cyclotron resonance chemical vapour deposition (ECR-CVD) technique from a mixture of methane, silane and hydrogen, and using diborane and phosphine as doping gases. The effects of changes in the microwave power on the deposition rate and optical bandgap were investigated, and variations in the photoand dark-conductivities and activation energy were studied in conjunction with film analysis using the Raman scattering technique. In the case of boron-doped samples, the conductivity increased rapidly to a maximum, followed by rapid reduction at high microwave power. The ratio of the photo- to dark-conductivity (σph/σd) peaked at microwave power of ~600 W. Under conditions of high microwave power, Raman scattering analysis showed evidence of the formation and increase in the silicon microcrystalline and diamond-like phases in the films, the former of which could account for the rapid increase and the latter the subsequent decrease in the *** the case of phosphorusdoped SiC:H samples, it was found that increase in the microwave power has the effect of enhancing the formation of the silicon microcrystalline phase in the films which occurred in correspondence to a rapid increase in the conductivity and reduction in the activation energy The conductivity increase stabilised in samples deposited at microwave power exceeding 500 W probably as a result of dopant saturation. Results from Raman scattering measurements also showed that phosphorus doping had the effect of enhancing the formation of the silicon microcrystals in the film whereas the presence of boron had the effect of preserving the amorphous structure.

关键词： ECR A Comparative Study of Boron and Phosphorus Doping Effects in SiC H Films Prepared by ECR-CVD

Seismic Performance of Steel Reinforced Ultra High-strength Concrete Columns

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四川大学学报（工程科学版） 2009年第3期41卷 216-222,230页

作者：贾金青 Inst.of Structural Eng. Dalian Univ.of Technol.

The seismic performance of steel reinforced ultra-high-strength concrete columns(SRSHC) with various shear-span ratios(λ) were studied through a series of *** concrete compressive cube strength value of experimental specimens ranged from 92.9 MPa to 108.1 *** main experimental variables affecting seismic performance of specimens were axial load ratio and stirrup reinforcement *** columns(λ=2.75) subjected to low cyclic reversed lateral loads failed mainly in the flexural-shear mode failure and columns(λ≤2.0) subjected to low cyclic reversed lateral loads failed mainly in the shear mode *** force-displacement hysteretic curves and skeleton curves were *** of the specimen displacement ductility was *** results indicate that ductility decreases with axial pressure ratio increasing,and increases with stirrup reinforcement ratio *** values of axial pressure ratio and minimum stirrup reinforcement ratio of columns are proposed to satisfy definite ductility *** suggested values provide a reference for engineering application and for the amendment of the current Chinese design code of steel reinforced concrete composite structures.

关键词：建筑结构建筑物抗震设计混凝土结构

Effect of Pulse Current on Interface Microstructure and Bonding Properties of TA1/304 Double-Layer Clad plates

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CHINESE JOURNAL OF MECHANICAL ENGINEERING 2024年第1期37卷 1-16页

作者： Guo, Xiongwei Ren, Zhongkai Zhang, Pengjie Zhang, Chao Jiang, Shuyong Zhang, Qi Wang, Tao Huang, Qingxue Taiyuan univ technol Coll Mech & Vehicle Engn Taiyuan 030024 Peoples R China Taiyuan univ technol Minist Educ Engn Res Ctr Adv Met Composites Forming Technol & Taiyuan 030024 Peoples R China Natl Key Lab Met Forming technol & Heavy Equipment Taiyuan 030024 Peoples R China Taiyuan univ technol China Australia Joint Res Ctr Taiyuan 030024 Peoples R China

It is difficult to effectively improve the low bonding strength of TA1/304 clad plates. This study proposes a new process for applying pulse current (1500 A, 500 Hz, 50% duty cycle) to TA1/304 clad plates during the rolling process, which changes the interface microstructure and effectively improves the bonding strength of the clad plates. The influence of the pulsed current on the interface microstructure and bonding strength was systematically studied. The results indicate that the clad plate is initially bonded at 750 degrees C and 35% reduction ratio under electrically-assisted rolling (EAR), and finally the higher bonding strength is obtained at 850 degrees C and 48% reduction ratio, reaching 395 MPa. The strengthening of the interface element diffusion and grain refinement under the action of the pulsed current are important reasons for the improvement in the bonding strength of the clad plate. This discovery provides new ideas for the preparation of clad plates with high bonding performance.

关键词： TA1/304 clad plates Electrically-assisted rolling (EAR) Element diffusion Microstructure Tensile shear strength

Electrochemical Properties of Sn Doped AB_5 Non-Stoichiometric Hydrogen Absorbing Alloys-Ⅱ

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Journal of Rare Earths 2001年第1期19卷 29-33页

作者：王志兴李新海陈启元郭华军彭文杰郭炳昆 Central South univ. of technol. Changsha 410083 China

The effects of some substituting elements on the specific discharge capacity, activation and cycling life of AB 5 non stoichiometric hydrogen absorbing alloys were studied electrochemically. Results show that the characteristics of hydrogen absorbing alloys under low current density are greatly improved through the substitution of Ni by Sn, Co, and Mn. Three hydrogen storage alloys, i.e., La(NiSn) 5.14 , La(NiSnCo) 5.12 and La(NiSnMn) 5.12 have the higher specific capacity and easy activation. However, Al in the alloy shows the opposite effect on the electrochemical properties. Under high current density, the discharge capacity and potential of La(NiSn) 5.14 is superior to La(NiSnCo) 5.12 and La(NiSnMn) 5.12 , but the cycling life of La(NiSn) 5.14 is very short. The addition of Mn, Co and Al to the alloys improves the cycling characteristics. In all these alloys, La(NiSnCo) 5.12 is considered as an ideal hydrogen storage alloy.

关键词： rare earths hydrogen absorbing alloy nonstoichiometry Ni MH battery electrochemistry

Hydration Characteristics of Sodium Sulfate Slag Cement System

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Journal of Wuhan university of technology(Materials Science) 2001年第4期16卷 45-47,61页

作者：陈友治 Wuhan univ technol Coll Mat Sci & Technol Wuhan 430070 Peoples R China Chongqing Jianzhu univ Chongqing Peoples R China

The hydration characteristics by thermal analysis (DTA) were determined, and an isothermal calorimeter (IC) was used to study the pastes. The experimental results indicate: (1) The main hydration products of SSC are C-S-H (I) gel with a low Ca/Si ratio, crystalline Thomsonite-type and AFt-type phases containing certain alkali cations; (2) No phases of the AFm-type and high alkaline Ca (OH)(2) in SSC system could benefit the hydrated cements to improve its strength and durability; (3) Crystalline Thomsonite-type and AFt-type phases containing Na+ will greatly reduce free alkali and alleviate the harmness of alkali aggregate reaction (AAR) in SSC system; (4) Similar to ordinary Portland cement (OPC), the hydration process of SSC could be classified into five stage: initial, induction, acceleration, deceleration and decay; (5) Regardless of the activator used, the apparent activation energy is higher with the increased slag in cement system, and the rising temperature could promote the hydration of SSC.

关键词： sodium sulfate slag cement (SSC) hydration alkali cation crysta pline phase heat evolution apparent activation energy

Network Diffusion Framework to Simulate Spreading Processes in Complex Networks

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BIG DATA MINING AND ANALYTICS 2024年第3期7卷 637-654页

作者： Czuba, Michal Nurek, Mateusz Serwata, Damian Qiu, Yu-Xuan Jia, Mingshan Musial, Katarzyna Michalski, Radoslaw Brodka, Piotr Wroclaw univ Sci & technol Dept Artificial Intelligence PL-50370 Wroclaw Poland univ technol Sydney Data Sci Inst Ultimo NSW 2007 Australia

With the advancement of computational network science, its research scope has significantly expanded beyond static graphs to encompass more complex structures. The introduction of streaming, temporal, multilayer, and hypernetwork approaches has brought new possibilities and imposed additional requirements. For instance, by utilising these advancements, one can model structures such as social networks in a much more refined manner, which is particularly relevant in simulations of the spreading processes. Unfortunately, the pace of advancement is often too rapid for existing computational packages to keep up with the functionality updates. This results in a significant proliferation of tools used by researchers and, consequently, a lack of a universally accepted technological stack that would standardise experimental methods (as seen, e.g., in machine learning). This article addresses that issue by presenting an extended version of the Network Diffusion library. First, a survey of the existing approaches and toolkits for simulating spreading phenomena is shown, and then, an overview of the framework functionalities. Finally, we report four case studies conducted with the package to demonstrate its usefulness: the impact of sanitary measures on the spread of COVID-19, the comparison of information diffusion on two temporal network models, and the effectiveness of seed selection methods in the task of influence maximisation in multilayer networks. We conclude the paper with a critical assessment of the library and the outline of still awaiting challenges to standardise research environments in computational network science.

关键词： Surveys Nanoelectromechanical systems Computational modeling Machine learning Nonhomogeneous media Libraries Software computational framework seed selection influence maximisation spreading models temporal networks multilayer networks network science network control

Degradation particles derived from high-purity magnesium inhibit osteogenic differentiation through regulation of macrophage polarization

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Journal of Materials Science & technology 2023年第8期139卷 113-119页

作者： Yu Sun Han Yu Hongzhou Peng Xinbao Kang Zhaoxiang Peng Xieping Dong Wenhui Wang Yang Song Xiaonong Zhang State Key Laboratory of Metal Matrix Composites School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China Department of Orthopaedic Surgery Ningbo Medical Treatment Center Lihuili HospitalNingbo 315040China Department of Orthopaedic Surgery Jiangxi People’s HospitalNanchang 330006China Suzhou Origin Medical technology Co.Ltd. Jiangsu 215513China

Magnesium(Mg)and its alloys have great potential as orthopedic implant candidates,which could release various bioactive substances during *** particles(DPs)are one of the degradation products,but the osteoimmunology effects are still *** this study,the effect of DPs on the polar-ization of macrophages and their release of cytokines was *** results verify that excessive generation of DPs from biodegradable Mg can induce macrophages to realize polarization of proinflamma-tory M1 ***,macrophages secrete proinflammatory cytokines to inhibit the osteogenic differentiation of rat bone marrow stem cells(rBMSCs).This suggests that the effects of DPs should be considered when evaluating Mg-based *** continuously produced with the degradation of Mg-based implants may influence osseointegration.

关键词： Magnesium Degradation particles Macrophage Phagocytosis Osteoimmunology

NUMERICAL SIMULATION FOR THE SIMPLE SHEAR TEST IN AMORPHOUS GLASSY POLYMERS

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Acta Mechanica Solida Sinica 1999年第1期12卷 36-42页

作者： Hu Ping Wang Demin Jilin univ technol Inst Automobile Panel Forming Technol Changchun 130025 Peoples R China Jilin univ technol Dept Appl Mech Changchun 130025 Peoples R China

In this paper , a driving stress finite element method ofelastic-plastic large deformation based on implicit time integratingalgorithm and an eight-chain molecular network model is used for thenumerical simulation of the simple shear test ofpolycarbonate(PC)materials. The simulated results are compared withexperimental ones. The strain localiztaion propagation for the shearband deforma- tion for simple shear deformation is investigatednumerically. The effects of microstructure parameters in the model onstrain softening and orientation hardening of the PC are discussed indetail.

关键词： driving stress finite element method eight-chain molecular network model polycarbonate

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