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Tungsten carbide coatings with different binders prepared by low power plasma spray system

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中国有色金属学会会刊：英文版 2004年第Z1期14卷 77-82页

作者： GAO Yang M.F.Morks FU ying-qing Materials and Technology Institute Dalian Maritime University Dalian 116026 China Materials and Technology Institute Dalian Maritime University Dalian 116026 China Central Metallurgical Research and Development Institute P.O. Box 87 Helwan El-Tibben Cairo Egypt Materials and Technology Institute Dalian Maritime University Dalian 116026 China

Thermal spraying of cermet coatings is widely used for protection of machining parts against wear and corrosion. These coatings consist of WC particles in metal binders such as Co, Cr and Ni. Three kinds of WC powders with different metal binders (Co, NiCr and CoCr) were sprayed by low power plasma spray system on Al-Si-Cu alloy substrate. Fundamental aspects of sprayed cermet coatings, including (i) the effects of binder type on the coating structure, (ii) the hardness and (iii) the microstructure, were investigated. All cermet coatings have the same phase structure such as WC and W2 C. However, the intensities of these phases are different in each coating, mainly due to the difference in solidification rate in each case. Moreover, the hardness measurements are found to be different in each coating. The results show that, binder type has a significant effect on the physical and mechanical properties of the sprayed coatings.

关键词： tungsten carbide binders aluminum alloy substrate hardness microstructure

Effect of vacuum annealing on the characteristics of composite pellets containing DBSA-doped polyaniline and Fe nanoparticles

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International Journal of Minerals,Metallurgy and Materials 2009年第2期16卷 236-241页

作者： qing Wu Hong Qiu Chun-ying Fang Kun Fang School of Applied Science University of Science and Technology Beijing Beijing 100083 China Material Research Center Beijing Institute of Science and Technology Beijing 100081 China

The DBSA-PANI-Fe composite powder with 50wt% of Fe nanoparticles was prepared by mechanically mixing the DBSA-doped polyaniline powder and Fe nanoparticles. The composite powder was compacted to pellets and the pellets were annealed in vacuum at 443,493,543, and 593 K for 60 and 120 min. The conductivity of the pellet increases markedly with increasing the annealing temperature up to 493 K, and then decreases with further increasing the annealing temperature. When the pellet was annealed at 493 K for 60 min, the increment of conductivity reaches a maximum value, and the conductivity is 2.6 times as large as that of the pellet unannealed. The conductivities of the pellets annealed under the conditions of 543 K/120 min, 593 K/60 min, and 593 K/120 min are lower than the conductivity of the pellet unannealed. For all the pellets, the variation in conductivity with temperature reveals that the charge transport mechanism can be considered to be 1-D variable-range-hopping （1-D VRH）. The composite pellet shows a magnetic hysteresis loop independent of the annealing condition. The saturation magnetization is about 5.4×10^4 emu/kg. The saturation field and the coercivity are estimated to be 4.38×10^5 and 3.06×10^4 A/m, respectively. The crystalline structure ofFe nanoparticles in the composites does not change with the annealing condition. The annealing condition cannot destroy the polymer backbones.

关键词： doped polyaniline dodecylbenzene sulfonic acid (DBSA) Fe nanoparticles vacuum annealing structure conductivity magnetization

Haptics-equiped interactive PCI simulation for patient-specific surgery training and rehearsing

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Science China(Information Sciences) 2016年第10期59卷 233-238页

作者： Shuai LI qing xia Aimin HAO Hong QIN Qinping ZHAO State Key Laboratory of Virtual Reality Technology and Systems Beihang University Department of Computer Science Stony Brook University

Despite the long history of medical simulations, suffering from the patient-specific heterogeneous heart physiological structure and complex intravascular procedures, it is still challenging for patient-specific percutaneous coronary intervention(PCI) surgery simulation. In this paper, we advocate a haptics-equiped interactive prototype system towards PCI surgeons training and patient-specific surgery rehearsing, which can afford trainees the opportunity to approximately experience the entire PCI procedures and customized emergency cases that might occur in common clinical settings. The full simulation covers tissue deformation, catheter and wire simulation, X-ray simulation, haptic feedback, and 3D realistic rendering, which in all give rise to the integrated physical, visual, haptic, and procedural realism. Our system can accommodate various comprehensive operations involved in PCI-related procedures, including feeding wires, releasing stents, injecting contrast medium, simulating X-ray, bleeding, etc. Moreover, our system framework is fully built upon CUDA, and thus can achieve real-time performance even on a common desktop. The high-fidelity, real-time efficiency and stableness of our system show great potentials for its practical applications in clinical training fields.

关键词： percutaneous coronary intervention(PCI) PCI surgery simulation patient-specific surgery rehearsing physically-based modeling haptics

Synthesis of TiO_2 films on glass slides by the sol-gel method and their photocatalytic activity

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Rare Metals 2009年第4期28卷 378-384页

作者： ZHANG Cuixuan CHEN Rufen ZHOU Juan CHENG Jianhui xia qing College of Chemistry and Material Science Hebei Normal University Shijiazhuang 050016 China

Titanium dioxide （TiO2） films with rod-like and sphere-like TiO2 particles were prepared on glass slides employing the sol-gel method. The shape and size of TiO2 particles were controlled using different concentrations of sodium dodecylbenzensulfonate （SDBS）. By increasing the mole ratio of SDBS, the shape of TiO2 particles transformed from rod-like to sphere-like. Also, the size of TiO2 particles became gradually smaller. Then, the size became bigger when an excess amount of SDBS was added. The films were mainly composed of anatase titania and the relative content of anatase increased with the increasing amount of SDBS. The photocatalytic activity of the TiO2 films that were added with SDBS was higher than that without SDBS. When the concentration of SDBS was 8.0 at%, the sample exhibited the best photocatalytic activity.

关键词： titanium dioxide film synthesis photocatalytic activity particle shape

Analysis of the buoyancy-induced heat transferin a rotating cavity

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航空动力学报 2012年第3期27卷 566-571页

作者： Tian, Shu-qing Xue, Hang Gao, Chao Li, ying Technology Department Aviation Industry Corporation of China Commercial Aircraft Engine Company Limited Shanghai 200241 China Institute of Steam and Gas Turbines Rheinisch-Westfaelische Technische Aachen University Germany Civil Aircraft Marketing and Sales Aviation Industry Corporation of China International Holding Corporation Beijing 100101 China School of Jet Propulsion Beijing University of Aeronautics and Astronautics Beijing 100191 China Hekou Oil Production Plant of Shengli Oilfield Sinopec Group Shandong Dongying 257200 China

In order to get a better knowledge of the heat transfer in compressor cavities of aero-engines,the simplified rotating cavity with two-plane discs,a shaft and a cylindrical rim has been investigated numerically and compared with the available *** numerical results in agreement with the available experiments show large-scale *** disk local Nusselt numbers show mainly radial rising distributions for the heated disks with radial rising temperature *** the present work,at the Reynolds number of 20 000,the disk local Nusselt numbers are the correlations of the local Grashof number to the power of 1.89-2.6,and the value of the power is increased as the rotational Reynolds number goes *** the rotational Reynolds number of 800 000,the local Nusselt numbers are the correlations of the local Grashof number to the power of 0.68-2.6,and the value of the power is decreased as Reynolds number goes *** area-averaged disk Nusselt number is the correlation of the Reynolds number to the power of 0.479 and the rotational Grashof number to the power of 0.12.

关键词： buoyancy force Coriolis force rotating cavity heat transfer turbine

Risk analysis for a cascade reservoir system using the brittle risk entropy method

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Science China(Technological Sciences) 2016年第6期59卷 882-887页

作者： YANG Yin REN qing Wen TIAN ying XIONG Yao College of Hydraulic Conservation and Hydropower Engineering Hohai University Department of Engineering Mechanics Hohai University

The principal means of conserving water and utilizing hydropower in China is to exploit the use of a series of reservoirs in a cascade. This method and its inherent engineering safety problems are receiving increasing attention nowadays. In the field of engineering safety analysis, much work has focused on single reservoir projects in the past few years, but there is little research available on the safety risk analysis of cascade reservoirs, either within China or internationally. Therefore, a framework for risk analysis on the cascade reservoir system based on the theory of system engineering is constructed in this article. A cascading failure model is established and the connection degree factor discussed. In addition, the importance degree of the subsystem, which can be calculated by combining the analytical hierarchy process and the entropy weight method, is explained. According to brittleness theory of a complex system, brittle risk entropy is proposed as a performance index for measuring the collapse uncertainty of the cascade reservoir system. In addition, the brittle risk of the cascade reservoir system is predicted, which provides a reference for safety analysis in water conservation and hydropower construction projects in China.

关键词： cascading failure model safety analysis risk assessment complex system brittle risk entropy

Synthesis, UV-curing Behavior and Surface Properties of New Fluorine-containing Aromatic Oxetane Monomers

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Chinese Journal of Polymer Science 2018年第4期36卷 521-527页

作者： Shu-qing Fang Yu-Lian Pang ying-Quan Zou College of Chemistry Beijing Normal University

In this paper, we combined high-end cationic UV-curable material with fluorinated chain obtaining a series of new fluorine-containing aromatic oxetane monomers via a mild nucleophilic substitution reaction. The structures and properties of monomers were characterized using ~1 H-NMR, ^（19） F-NMR, dynamic viscosity tests and differential scanning calorimetry（DSC）. It was determined that all of the fluorinated monomers obtained had much lower viscosity and higher thermostability after the introduction of hexafluorobenzene. Then, UV-curable coatings were prepared using four fluorine-containing aromatic oxetane monomers（FOX1-4）; the UV-curing kinetics, with three kinds of initiators, and properties of the cured films were evaluated using real-time Fourier transform infrared（FTIR） spectroscopy, water and diiodomethane contact angle tests, surface energy calculations and scanning electron microscopy（SEM）. The FTIR spectroscopy results showed that the coatings possessed excellent conversion rate（〉 99% with liquid initiator PAG-201 in 150 s）, and as the fluorine content increased, the monomers exhibited decreased mobility with the increasing viscosity and worse solubility with fluorinated monomers, resulting in a lower conversion rate. Moreover, the coatings possessed favorable hydrophobic and oleophobic properties and low surface energies owing to the fluoride chains floating to the membrane-air interface, which was also confirmed by discrete concave structures in SEM images. These new kinds of monomers can replace traditional fluorinated cationic monomers applied to the fingerprint resistant, fouling resistant, scratch resistant and anti-aging coatings, adhesives or printing ink materials.

关键词： Fluorine-containing monomers Oxetane UV-curing kinetics Surface properties

On Cultural Self-Confidence and Communication from the Perspective of“Belt and Road”Initiative

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学术界 2018年第12期 249-259页

作者： xia ying Wang Yang School of Foreign Languages Chongqing Three Gorges University Chongqing 404020

An important part of the "Belt and Road " Initiative is to achieve people-to-people bonds. People-to-people bonds are certainly based on cultural self-confidence and cultural self-awareness. Cultural self-confidence is an important cultural strategy put forward by the party and the country in the vision of contemporary society,and an important deployment to realize the great rejuvenation of the Chinese nation. This paper first gives a brief overview of the advantages of cultural self-confidence in external communication,and then analyzes the opportunities and challenges that cultural self-confidence faces in external communication in the newera. Finally,it focuses on exploration on the external communication ways of cultural self-confidence in the "Belt and Road"Initiative. O nly based on the deep understanding of local culture can we can shape the soul of culture in the process of further opening-up and external communication to the outside world,and enhance the cultural self-aw areness of the people; build a solid foundation of culture and promote cultural exchanges with other countries.

关键词： “Belt and Road”Initiative people-to-people bonds,cultural self-confidence,external communication

Brownian Dynamics Simulations of Rigid Polyelectrolyte Chains Grafting to Spherical Colloid

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Chinese Journal of Polymer Science 2018年第6期36卷 791-798页

作者： qing-Hai Hao Zhen Zheng Gang xia Hong-Ge Tan College of Science Civil Aviation University of China

Brownian dynamics simulations are employed to explore the effects of chain stiffness and trivalent salt concentration on the conformational behavior of spherical polyelectrolyte brush. The rigid brush adopts bundle-like morphology at a wide range of trivalent salt concentration. The number variation of bundles pinned on the colloid surface shows a non-monotonic profile as a function of the chain stiffness. The radial distributions of monomers and ions and the charge ratio between condensed ions and monomers are calculated. The charge inversion is observed for the high salt concentration regardless of chain rigidity. Furthermore, the pair correlation functions of monomer-monomer and monomer-salt cation are used to elucidate the aggregated mechanism of the bundle-like structure.

关键词： Brownian dynamics simulation Spherical polyelectrolyte brush Chain stiffness Trivalent salt concentration Pinned bundle morphology