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Understanding micro-diffusion bonding from the fabrication of B_4C/Ni composites

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International Journal of Minerals,Metallurgy and Materials 2018年第3期25卷 365-374页

作者： Miao Wang Wen-xian Wang Hong-sheng Chen yu-li li College of Materials Science and Engineering Taiyuan University of Technology Key Laboratory of Interface Science and Engineering in Advanced Materials Ministry of Education Taiyuan University of Technology

A Ni-B_4C macroscopic diffusion welding couple and a Ni-15 wt% B_4C composite fabricated by spark plasma sintering(SPS) were used to understand the micro-scale diffusion bonding between metals and ceramics. In the Ni-B_4C macroscopic diffusion welding couple a perfect diffusion welding joint was achieved. In the Ni-15 wt% B_4C sample, microstructure analyses demonstrated that loose structures occurred around the B_4C particles. Energy dispersive X-ray spectroscopy analyses revealed that during the SPS process, the process of diffusion bonding between Ni and B_4C particles can be divided into three stages. By employing a nano-indentation test, the room-temperature fracture toughness of the Ni matrix was found to be higher than that of the interface. The micro-diffusion bonding between Ni and B_4C particles is quite different from the Ni-B_4C reaction couple.

关键词： B4C/Ni composites spark plasma sintering micro-diffusion welding microstructure nano-mechanical property

DESIGN TECHNOLOGY FOR INJECTION MOLD PARTING SURFACE BASED ON CASES AND KNOWLEDGE

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Chinese Journal of Mechanical Engineering 2005年第4期18卷 609-612页

作者： yu Tongmin li Guanhua li Youmin Lan Jian Key Laboratory for Precision and Nontraditional Machining Technology of Ministry of Education Dalian University of Technology Dalian 116024 China

On the basis of the comprehensive analysis about the automatic generation of the injection mold parting surface, the parting surface design method which introduces knowledge and case-based reasoning （CBR） into the computer-aided design is described by combining with the actual characteristic in injection mold design, and the design process of case-based reasoning method is also given. A case library including the information of parting surface is built with the index of main shape features, The automatic design of the mold parting surface is realized combined with the forward-reasoning method and the similarity solution procedure. The rule knowledge library is also founded including the knowledge, principles and experiences for parting surface design. An example is used to show the validity of the method, and the quality and the efficiency of the mold design are improved.

关键词： Injection mold Parting surface design Case-based reasoning (CBR)Similarity solution

Maxwell-Chern-Simons Casimir Force Between Perfectly Conducting Parallel lines

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Communications in Theoretical Physics 2001年第10期36卷 431-432页

作者： ZHENG Tai-yu ZHENG li li Chang-Song The Institute of Theoretical Physics Northeast Normal University Changchun 130022 China The Center of Theoretical Physics Jilin University Changchun 130000 China The Institute of Theoretical Physics Northeast Normal University Changchun 130022 China Technique School of Yanbian Yanji 133000 Jilin Province China

Using Feynman path integral method we calculate the Casimir force of Maxwell Chern Simons Abelian gauge field between perfectly conducting parallel lines.

关键词： Casimir force, path integral method, Maxwell Chern Simons gauge field

Theoretical Calculation of a Focused Acoustic Field from a linear Phased Array on a Concave Cylindrical Transducer

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Chinese Physics Letters 2011年第10期28卷 138-141页

作者： yu li-li SHOU Wen-De HUI Chun School of Biomedical Engineering Shanghai Jiao Tong UniversityShanghai 200030 Shanghai Institute of Ultrasound in Medicine Shanghai 200233

A new linear phased array on a concave cylindrical transducer is designed for meeting the specific requirements of applications for interstitial thermal *** the array,a focal line can be generated rapidly and the focal position can be adjusted in the proper range without the use of complex mechanical *** focused acoustic field distributions in the axial,radial and azimuthal directions of the transducer are investigated theoretically by numerical *** of the focal distance,steering angle,element arc-width,arc-space between adjacent elements and number of elements on the acoustic field are also thoroughly *** important results are obtained.

关键词： Transducer Focus thoroughly

In-situ Investigation of BBr_3/benzene Solution by Fourier Transformation Infrared Spectroscopy

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Chemical Research in Chinese Universities 2009年第5期25卷 733-737页

作者： yu li-li GAI li-gang CUI De-liang WANG Qi-long State Key Laboratory of Crystal Materials Shandong University Jinan 250100 P. R. China School of Chemical Engineering Shandong Institute of Light Industry Jinan 250353 P. R. China

By means of the in-situ Fourier transformation infrared spectroscopy（FTIR）, the properties of BBr3/ benzene solution, which is usually used as the reactant and solution to synthesize BN by benzene-thermal method, have been investigated. The results show that there are some side reactions between BBr3 and benzene：（1） BBr3 as an electron-deficient molecule reacts with benzene at room temperature; （2） below 100℃, substitution of Br atom for H atom of benzene（ring-H） dominates in BBr3/benzene solution; （3） cracking of benzene ring occurs at a temperature above 100℃; （4） decomposition of benzene molecules and formation of long-chain aliphatic compounds feature the spectra of BBr3/benzene solution collected at above 160℃, They are unfavor for BN to form when BBr3 is excessive in the synthesis of BN by benzene-thermal route. On the basis of the experimental results, a coordination reaction mechanism via a η^2-C6H6 binding mode in BBr3/benzene solution is suggested.

关键词： In-situ FTIR technique BBr3 Benzene Boron nitride Reaction mechanism

Corrosion Behavior of B_4C/6061Al Neutron Absorber Composite in Different H_3BO_3 Concentration Solutions

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Acta Metallurgica Sinica(English Letters) 2016年第11期29卷 1037-1046页

作者： yu-li li Wen-Xian Wang Hong-Sheng Chen Jun Zhou Qiao-Chu Wu School of Materials Science and Engineering Taiyuan University of Technology Key Laboratory of Interface Science and Engineering in Advanced Materials Ministry of Education Taiyuan University of Technology Department of Mechanical Engineering Pennsylvania State University Erie The Behrend College

In this study, electrochemical corrosion tests, full-soak corrosion tests and associated microstructure analysis were conducted to investigate the corrosion behaviors of B4C/6061Al neutron absorber composites（NACs） manufactured by powder metallurgy method in solutions having different boric acid（H3BO3） concentrations（500, 2500 and 10,000 ppm）. In electrochemical corrosion tests, B4C/6061Al NACs demonstrate the highest（short-term） corrosion resistance in the 2500 ppm H3BO3 solution. While for full-soak corrosion tests, the B4C/6061Al NACs show the highest（long-term） corrosion resistance in the 500 ppm H3BO3 solution. This difference is found to be mainly due to the formation of different surface morphologies during these two different corrosion tests. As noticed, a layer of Al（OH）3was formed on the composite surface during full-soak corrosion tests, but it cannot be found in the electrochemical corrosion tests. The full-soak corrosion mechanism of the B4C/6061Al NACs in the H3BO3 solution is found to be primarily determined by the dynamic balance between the formation and dissolution rates of the oxide film, which is mainly controlled by the density of H~＋ ions in the solution.

关键词： B4C/6061Al NACs Powder metallurgy Electrochemical corrosion Full-soak corrosion

Theoretical study on the reaction of VS^+(~3∑^-,~1Γ)with CO

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Chinese Chemical Letters 2008年第8期19卷 1008-1011页

作者： Shi Wen yu li Qing Yin li Feng Yao Ming li Xiao Guang Xie Department of Chemistry Yunnan University Kunming 650091 China

Two possible reaction mechanisms of VS^＋（^3∑^-, 1^Г） with CO in the gas phase have been studied by using B3LYP/TZVP and CCSD（T）/6-311＋G （3df, 3pd） methods： the O/S exchange reaction （VS^＋＋CO→VO^＋＋CS） and the S-transfer reaction （VS^＋＋ CO → V^＋＋ COS）. The two reactions proceed via two-step and one-step mechanism, respectively. The barriers of the triplet and singlet PESs are 30.6 and 50.9 kcal/mol, respectively, for O/S exchange reaction and 7.3 and 50.2 kcal/mol, respectively, for the S-transfer reaction. The results indicate that the triplet ground state reaction is more favorable, and the S-transfer reaction is more favorable than the O/S exchange reaction, which is in good agreement with the experimental observation.

关键词： Vanadium sulfide ion CO Reaction CCSD(T)

Grinding Properties of Abandoned Concrete

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Journal of China University of Mining and Technology 2007年第2期17卷 281-285页

作者： ZHENG Fang-yu WANG li-jiu li Qiang School of Civil and Hydraulic Engineering Dalian University of Technology Dalian Liaoning 116024 China

The grinding properties of abandoned concrete, which consists primarily of hardened cement, limestone aggregate and river sand, are studied. Theoretical models of grinding are used to explain the experimental observation. The results show that 1) The principle disintegration mechanism of hardened cement and river sand is volumetric grinding, although at later stages grinding of cement becomes difficult because of its flaked structure; 2) The lime- stone grinding process can be divided into two steps. First, volumetric grinding, with an obvious component of surface grinding, followed by primarily surface grinding as the micro-particle content increases; 3) Initially, the principle mechanism of grinding limestone and river sand is volumetric grinding, albeit less efficient grinding than if these components were ground separately, and; 4) After 10 to 20 min of grinding the grinding bottleneck phenomenon ap- pears and after 20 min of grinding the content of micro-particles is large and surface grinding is the main mechanism while the particle size of the mixture is smaller than that of separately ground river sand and cement but bigger than that of separately ground limestone.

关键词： abandoned concrete cement stone limestone river sand grinding

Selective removal of phenol by spherical particles of α-,β- and γ-cyclodextrin polymers： kinetics and isothermal equilibrium

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Frontiers of Chemical Science and Engineering 2013年第2期7卷 162-169页

作者： Qingchuan CHEN Yicun WEN yu CANG li li Xuhong GUO Rui ZHANG State Key Laboratory of Chemical Engineering East China University of Science and Technology Shanghai 200237 China

Spherical particles of α-,β- and γ-cyclodextrin （CD） polymers to efficiently remove phenol from waste water were prepared by reverse suspension polymerization with epichlorohydrin as crosslinker in liquid paraffin. By controlling the amounts of crosslinker and water, well- defined spherical polymer particles with controllable size were obtained. Due to the selective inclusion associations between CD groups and phenol, these CD spherical polymer particles were demonstrated to be ideal candidates for removal of phenol. Among them β-CD polymer particles showed the best performance. The kinetics and isothermal equilibrium models were used to fit the experimental data of phenol removal from aqueous solution using these CD polymer particles. It was found that the kinetics followed the Ho and Mckay equation, suggesting that the adsorption process of phenol was controlled by diffusion and the host-guest interaction between CD and phenol. Equilibrium isothermal data can be well fitted by the Freundlich equation. The negative free energy change indicated the spontaneous nature of adsorption of phenol by α-,β- and γ-CD spherical polymer particles, while the lowest free energy for β-CD polymer reflected its best adsorption ability, compared to α- and γ- CD polymer particles.

关键词： cyclodextrin polymer particles phenol,kinetic models adsorption isotherm equilibrium models