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Study on the cluster of floating dross before nucleating during hot-dipping process

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Science china Chemistry 2005年第1期48卷 83-88页

作者： WEI Yunhe1, ZHANG Changqiao1, QIN Jingyu2.& LIU Chengbu1 1. School of Chemistry and Chemical Engineering, Shandong university, jinan 2.0100,{2. 2. The key laboratory of Liquid Structure and Heredity of materials of Ministry of Education, Shandong university, jinan 2.0061,{2. School of Chemistry and Chemical Engineering Shandong University Jinan China The key laboratory of Liquid Structure and Heredity of {2. of Ministry of Education Shandong University Jinan China

During hot-dipping in molten Zn-55Al, the forming of “floating” dross is closely re- lated with the interaction between the Al and the Fe atoms. Utilizing the thita-thita X-ray diffraction and the Percus-Yevick hard sphere model, this paper investigates the structure of molten Al3Fe that is an approximant of partial melt in practical Zn-55Al alloy melt. It is found that in the melt there exist clusters that resemble the structure of intermetallic compound Al3Fe. The strong in- teraction between Al and Fe atoms is also indicated by the deficiency of the coordination number from 12.and the shrinkage of averaged atomic diameter. Based on such information, it is specu- lated that in the molten Zn-55Al, with the accumulation of Fe, Al3Fe-like clusters form with priority, then grow into dross. On the other hand, after deflating of the effective hard sphere diameter of pure Al atom and enlarging that of the pure Fe atom, the modified model can achieve reasonable fit to the experimental structure factor. Hard sphere modeling also gave a good estimation of the mass density 3.65 g/cm3 of liquid Al3Fe alloy at 1550℃. Compared with the density of 3.7 g/cm3 of Zn-55Al, the reason for dross floating is satisfactorily understood.

关键词： hot-dipping, dross, Al3Fe alloy, molten structure, P-Y model.

Magnetron sputtering synthesis of large area well-ordered boron nanowire arrays

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Science china(Physics,Mechanics & Astronomy) 2004年第4期47卷 403-415页

作者： CAO Limin1,2. ZHANG Ze2.& WANG Wenkui1,2.1. key laboratory of Metastable {2. Science and Technology and College of {2. Science and Engineering, Yanshan university, Qinhuangdao 066004, china 2. Institute of Physics, Chinese Academy of Sciences, Beijing 100080, china key laboratory of Metastable {2. Science and Technology and College of {2. Science and Engineering Yanshan University Qinhuangdao China Institute of Physics Chinese Academy of Sciences Beijing China

One-dimensionally nanostructured materials, such as nanowires and nanotubes, are the smallest dimensional structures for efficient transport of electrons and excitons, and are therefore critical building blocks for nanoscale electronic and mechanical devices. In this paper, boron nanowires with uniform diameters from 2. to 80 nm were synthesized by radio-frequency magnetron sputtering of pure boron powder and B2.3 powder mixtures in argon atmosphere. The boron nanowires produced stand vertically on the substrate surface to form well-ordered arrays over large areas with self- organized arrangements without involvement of any template and patterned catalyst. The high-density boron nanowires are parallel to each other and well distributed, forming highly ordered and uniform arrays. A more interesting and unique feature of the boron nanowires is that most of their tips are flat rather than hemispherical in morphologies. Detailed studies on its structure and composition indicate that boron nanowires are amorphous. Boron nanowire appears as a new member in the family of one-dimensional nanostructures. Considering the unique properties of boron-rich solids and other nanostructures, it is reasonable to expect that the boron nanowires will display some exceptional and interesting properties. A vapor-cluster-solid (VCS) mechanism was proposed to explain the growth of boron nanowires based on our experimental observations.

关键词： boron nanowires, magnetron sputtering, arrays, self-assembly.

Large-scale boron nanowire nanojunctions and their highly-oriented arrays

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Science china(Physics,Mechanics & Astronomy) 2004年第5期47卷 621-632页

作者： CAO Limin1,2. ZHANG Ze2.& WANG Wenkui1,2.1. key laboratory of Metastable {2. Science and Technology, Yanshan university, Qinhuangdao 066004, china 2. Institute of Physics, Chinese Academy of Sciences, Beijing 100080, china key laboratory of Metastable {2. Science and Technology Yanshan University Qinhuangdao China Institute of Physics Chinese Academy of Sciences Beijing China

Highly oriented multiple boron nanowire nanojunctions with unilateral feather- like morphology were first successfully prepared using a radio-frequency magnetron sputtering method. The branched boron nano-feathers always nucleate and grow on the same sidewall of the stems, and align in parallel to form multiple T- and/or Y-type nanojunctions. The diameters of the branches and the stems are in the range of 2.—40 and 60—80 nm, respectively. The thinner branches and thicker stems of the boron nanowires self-assembled into large-scale, highly ordered arrays on various substrates. During the formation and self-assembly of the arrays, no template or catalyst was needed. We believe that the approach presented here can be used to fabricate heterostructures with bottom-up assembly of a wide variety of one-dimensional nanostructures via the rational design of targets and the proper control of the experimental conditions.

关键词： boron nanowires, nanojunctions, self-assembly, magnetron sputtering.

Flatness and Profile Integration Control Model for Tandem Cold Mills

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Journal of Iron and Steel Research International 2012年第3期19卷 31-37页

作者： SHAN Xiu-ying1,2.3, LIU Hong-min1,2. JIA Chun-yu1,2. SUN Jian-liang1,2.(1. Engineering Research Center of Rolling Equipment and Complete Technology of Ministry of Education, Yanshan university, Qinhuangdao 066004, Hebei, china 2. State {2. laboratory of Metastable materials Science and Technology, Yanshan university, Qinhuangdao 066004, Hebei, china 3. Hot Tandem Rolling Factory, jinan Iron and Steel Co Ltd, jinan 2.0101, Shandong, china) Engineering Research Center of Rolling Equipment and Complete Technology of Ministry of Education Yanshan University Qinhuangdao Hebei China State key laboratory of Metastable {2. Science and Technology Yanshan University Qinhuangdao Hebei China Hot Tandem Rolling Factory Jinan Iron and Steel Co Ltd Jinan Shandong China

Using the effective matrix methods of flatness and profile control synthetically, the flatness and profile in- tegration control scheme for tandem cold mills is built in order to increase flatness and profile control precision of tan- dem cold mills. Corresponding control strategies are adopted for various control objectives of different stands and the coordination control strategies of various stands are given, which makes the on-line flatness control cooperate with on-line profile control and implements the parallel control of different stands. According to the measured flatness and profile data of some 1550 mm tandem cold mills, the control scheme is verified and the result indicates that the scheme has high flatness and profile control precision with steady and reliable control process. A new way and method is supplied for researching shade control of tandem cold mills.

关键词： flatness profile shape effective matrix tandem cold mill

Electron transport properties of boron-doped capped-carbon-nanotube-based molecular junctions

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Science Bulletin 2010年第36期55卷 4104-4107页

作者： ZHAO Peng1 & LIU DeSheng2.1 School of Science, university of jinan, jinan 2.002., china 2.School of Physics, State key laboratory of crystal materials, Shandong university, jinan 2.0100, china School of Science University of Jinan Jinan China School of Physics State Key Laboratory of Crystal Materials Shandong University Jinan China

Using the Landauer formalism that combines both the non-equilibrium Green’s function and first-principles density functional theory, the electron transport properties of a one-dimensional molecular junction based on capped carbon nanotubes with boron doping at various sites are investigated. The results show that the electron transport properties are strongly dependent on the boron-doping site. Negative differential resistance behavior can be observed when boron-atom dopants are present in the tip region.

关键词： carbon nanotube doping non-equilibrium Green’s function density functional theory

Numerical research on the 3D fiber orientation distribution in arbitrary planar flows

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Progress in Natural Science:materials International 2007年第11期17卷 1357-1362页

作者： Zhou Kun1 and Lin Jianzhong1,2.1. State key laboratory of Fluid Power Transmission and Control, Zhejiang {2., Hangzhou 31002., china 2. china Jiliang {2., Hangzhou 310018, china) State key laboratory of Fluid Power Transmission and Control Zhejiang University Hangzhou 310027 China china Jiliang university Hangzhou 310018 China

The fiber orientation distribution in a fiber suspension flow was investigated by a finite difference scheme in spherical coordinates. The diffusivity was transformed between Cartesian and spherical coordinates through tensor analysis to obtain efficiency. It is found that under simple shear flow condition the diffusivity in the azimuthal direction, Dr, has greater effect on the orientation distribution than that in the colatitude direction, Drθθ.

关键词： fiber suspension flow orientation distribution diffusivity

Numerical simulation of the efficiency of mixing in heterogeneous microchannels with patterned surface potentials

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Progress in Natural Science:materials International 2006年第12期16卷 1322-1328页

作者： ZHANG Kai~1, LIN Jianzhong~ 1,2.** and LI Huijun~1(1. State key laboratory of Fluid Power Transmission and Control, Zhejiang {2., Hangzhou 31002., china 2. china Jiliang {2., Hangzhou 310018, china) State key laboratory of Fluid Power Transmission and Control Zhejiang University Hangzhou 310027 China china Jiliang university Hangzhou 310018 China

The mixing of samples in heterogeneous microchannels with a periodically stepwise surface potential was analyzed numerically using the control volume method. The equations describing the wall potential and external potential were solved first to get the distribution of wall potential and external potential, respectively, then the momentum equation was solved to get the developed flow field. Finally, the mass transport equation was solved to get the concentration field. The simulation results show that the distribution of samples at the inlet of the microchannel determines its theoretical value of concentration, therefore, the pattern of the distribution of samples at the inlet and its corresponding velocity can be changed to get the desirable concentration of solute. The heterogeneous wall potential almost has no effect on the mixing of samples in two-inlet microfluidic devices. For three-inlet microfluidic devices, the comprehensive ability of transportation and mixing has an optimization when the ratio of periodic length of wall potential to the height of the microchannel is about 4.88. The above conclusions are helpful to the optimization of the design of microfluidic devices.

关键词： microchannel mixing efficiency electroosmosis numerical simulation.

Subsidence control and farmland conservation by solid backfilling mining technology

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中国有色金属学会会刊：英文版 2011年第S3期21卷 665-669页

作者： GUO Guang-li1, 2. FENG Wen-kai3, ZHA Jian-feng1, 2. 3, LIU Yuan-xu1, 2. WANG Qiang1, 2.1. key laboratory for Land Environment and Disaster Monitoring of the State Bureau of Surveying and Mapping,{2. university of Mining and Technology, Xuzhou 2.1116,{2. 2. Jiangsu key laboratory of Resources and Environmental Information Engineering,{2. university of Mining and Technology, Xuzhou 2.1116,{2. 3. State key laboratory of Geohazard Prevention and Geoenvironment Protection, Chengdu university of Technology, Chengdu 610059,{2. key laboratory for Land Environment and Disaster Monitoring of the State Bureau of Surveying and Mapping China University of Mining and Technology Xuzhou 221116 China Jiangsu key laboratory of Resources and Environmental Information Engineering China University of Mining and Technology Xuzhou 221116 China State key laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of Technology Chengdu 610059 China

Solid backfilling mining technology, which decreases the height of fissure zone and caving zone, and alleviates the subsidence, is a new technology for farmland conservation. Based on the situation analysis of farmland destruction in mining area, three ways for farmland protection were proposed. In order to improve the feasibility of this technology, the limited filling materials should be used to increase resources recovery ratio, and then the surplus materials could be backfilled into goaf. An index, namely farmland conservation ability, was put forward to optimize the ways for farmland conservation. At last, the Wanbei coal mine was taken as a case for farmland conservation. It was shown that 32.0 t dull coal was substituted and 52.hm2.farmland was conserved by solid backfilling mining in this coal mine.

关键词： solid backfilling farmland conservation mining subsidence equivalent mining height

Measurement of the linear electro-optic coefficient of a minute cBN sample

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Science china(Technological Sciences) 2005年第2期48卷 233-340页

作者： DOU Qingping1, , MA Haitao1, JIA Gang1, CHEN Zhanguo1 2.& ZHANG Tiechen3 1. College of Electronic Science and Engineering, State key laboratory on Integrated Optoelectronics, Jilin {2., Changchun 13002., china 2. Mudanjiang Normal Institute, Mudanjiang 157012. china 3. State key laboratory of Superhard materials, Jilin {2., Changchun 130012. china College of Electronic Science and Engineering State Key Laboratory on Integrated Optoelectronics Jilin University Changchun China Mudanjiang Normal Institute Mudanjiang China State key laboratory of Superhard {2. Jilin University Changchun China

Cubic boron nitride (cBN) is a kind of artificial (synthetic) crystal. Transverse electro-optic modulation in a minute cBN sample was carried out. Basing on the practical form of the crystal, we established the theoretical and experimental method according to the sample. For the first time, the linear electro-optic effect was observed in cBN, and half-wave voltage of the cBN sample was measured successfully. Furthermore, its linear electro-optic coefficient was calculated at 1.17×10?14 m/V.

关键词： cBN crystal, linear electro-optic effect, half-wave voltage, linear electro-optic coefficient.