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The precipitation and effect of nano nitrides in HSLC steel

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science china(Technological sciences) 2008年第7期51卷 989-998页

作者： FU Jie1, LIU YangChun1,2.& WU HuaJie1,3 1 School of Metallurgical and Ecological Engineering, University of science and technology {2., {2. 100083, china 2.Shougang technology Research Institute, Shougang (Group) Corporation, {2. 100041, china 3 Metallurgical Engineering Research Institute, University of science and technology {2., {2. 100083, china School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing China Shougang technology Research Institute Shougang (Group) Corporation Beijing China Metallurgical Engineering Research Institute University of Science and Technology Beijing Beijing China

The existing forms of N and Al in HSLC (high strength low carbon) steel produced by TSCR (thin slab casting and rolling process), the precipitation thermodynamics and kinetics of AlN, and its effects on structure and mechanical property are studied. The experimental results show that only a small quantity of nitrogen is com- bined into AlN in HSLC steel produced by TSCR and most of the nitrogen in steel is still free nitrogen. Aluminum-nitride is mainly precipitated during the period of slow air cooling after coiling, but not during rolling and water cooling. The acid-soluble aluminum has no obvious effect on the grain size and mechanical property of HSLC steel produced by TSCR whose acid-soluble aluminum content is 0.005%―0.043%. The precipitation of AlN is not the main cause of grain refinement of HSLC steel produced by TSCR, nor is AlN the dominating precipitate that has precipitation strengthening effect. The nano nitrides are not pure AlN, but have complex compositions.

关键词： thin slab casting and rolling high strength low carbon steel AlN nano nitride precipitation strengthening

Phenomenological Modeling of Warm Compaction and Experimental Verification

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International Journal of Minerals,Metallurgy and Materials 2000年第4期14卷 292-295页

作者： Shiju Guo, Tao Lin (Material science and Engineering School, University of science and {2. beijing, beijing 100083, china) Material science and Engineering School University of Science and Technology Beijing Beijing 100083 China

A phenomenological modeling approach to establishing the warm compaction equation and curves by modifying the regression equation of the room-temperature compaction curve is presented. An enhanced factor of compacting pressure is introduced into the equation in order to reveal the effects of powder/die temperature and filling height of powders on green density. Compaction curves yielded from this equation are consistent with the experimental data of ATOMET grade iron powders. The curves show that the powder/ die temperature should reduce as the filling heights of powders increase and that in some cases warm compaction can not give rise to a higher green density.

关键词： powder metallurgy warm compaction compaction equation Materials

Theoretical observation of hexaatomic molecules containing pentacoordinate planar carbon

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science china Chemistry 2008年第11期51卷 1030-1035页

作者： LUO Qiong State Key Laboratory of Explosion science and technology, {2. Institute of technology, {2. 100081, china State Key Laboratory of Explosion science and technology Beijing Institute of Technology Beijing China

The smallest molecules up to date containing a D5h pentacoordinate planar carbon (PPC) atom, CBe5 and CBe54-, are presented by means of ab initio calculations. To gain a better understanding about which electronic factors contribute to their stabilization, natural bond orbital (NBO) analysis and the nucleus independent chemical shifts (NICS) were calculated. The data reported here suggest that D5h CBe5 is σ aromaticity in nature, while in D5h CBe54- π aromaticity is dominating. The classical octet rule is well satisfied in both molecules, and is one of the fundamental reasons to understand the stability of the pentagon structures. The Be5 ring serves as σ donor in D5h CBe5, and π-acceptor in D5h CBe54-. The D5h CBe54- possessing 18 valence electrons with a closed-shell electron configuration is the most plau-sible candidate for experimental detection.

关键词： pentacoordinate planar carbon Be5 ring ab initio

Focus on polymer chemistry papers in science in china Series B:Chemistry of the year 2.09

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science china Chemistry 2010年第12期53卷 2663-2664页

作者： TIAN Ying science china Press,16 Donghuangchenggen North Street,{2. 100717,china science china Press Beijing China

The journal science in china Series B:Chemistry published 11 and 37 papers in polymer fields in 2.08 and 2.09,respectively,leading to a percentage increase of 2.6% and thereby a great historic breakthrough of the *** papers mainly focus on three fields:(1) polymer synthesis,(2. functional polymer materials and (3) biomedical *** research groups published a series of papers in science in china Series B:Chemistry and detailedly introduced their works in the related fields.

关键词： BZ ZK ATRP Focus on polymer chemistry papers in science in china Series B PDMAEMA

Compactness of the commutators of parabolic singular integrals

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science china Mathematics 2010年第10期53卷 2633-2648页

作者： CHEN YanPing1 & DING Yong2.3 1Department of Mathematics and Mechanics,University of science and technology {2.,{2. 100083,china 2.chool of Mathematical science,{2. Normal University,{2. 100875,china 3Laboratory of Mathematics and Complex Systems (BNU),ministry of Education of china,{2. 100875,china Department of Mathematics and Mechanics University of Science and Technology Beijing Beijing China School of Mathematical science Beijing Normal University Beijing China Laboratory of Mathematics and Complex Systems (BNU) Ministry of Education of China Beijing China

In this paper,the authors prove that the commutator [b,T] of the parabolic singular integrals is a compact operator on Lp(Rn)(1 < p < ∞) if and only if b ∈ VMO(Rn,ρ).The result is substantial improvement and extens... 详细信息

关键词： parabolic singular integrals commutators compactness BMO VMO

Annealing Texture Evolution of Ti-IF Steel during Batch Annealing

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International Journal of Minerals,Metallurgy and Materials 1998年第3期12卷 175-179页

作者： Jing Shi Xianjin Wang(Material science and Engineering School, University of science and {2. beijing, beijing 100083, china) Material science and Engineering School University of Science and Technology Beijing Beijing 100083 China

Texture development and recrystallization behavior of Ti-IF steel during Batch Annealing (BA) were investigared with X-ray diffraction and EBSP in lab, and the results were compared with research work on continu ous annealing (CA) with rapid heating rate. The basic tendencies are similar that eary nucleation takes place in ND fibers, RD fibers are consumed at the end of recrystallization, and ND texture dominates over annealing texture. However, the detailed texture transformation during batch annealing is different and somewhat more compicated than tha in rapid-heating process. Moreover, misorientation plays an important role in texture transformation of BA In addition, the results of EBSP are consistent with that of ODF well.

关键词： Ti-IF steel texture batch annealing X-ray diffraction EBSP

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 Materials science and technology and College of Materials science and Engineering, Yanshan University, Qinhuangdao 066004, china 2. Institute of Physics, Chinese Academy of sciences, beijing 100080, china Key Laboratory of Metastable Materials science and technology and College of Materials 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.

On some tests-based projection pursuit for elliptical symmetry of a high-dimensional distribution

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Chinese science Bulletin 1998年第6期43卷 450-458页

作者： JING Ping 1 and ZHU Lixing 2.1. Mathematics Lab, china University of Mining & technology, {2. 100083, china 2. Probability Lab, Institute of Applied Mathematics, Chinese Academy of sciences, {2. 100080, china Mathematics Lab China University of Mining & Technology Beijing China Probability Lab Institute of Applied Mathematics Chinese Academy of Sciences Beijing China

Some test statistics of Kolmogorov type and Cramér-von Mises type based on projection pursuit technique are proposed for the testing problem of sphericity of a high-dimensional distribution. The limiting distributions of the test statistics are derived under the null hypothesis and under any fixed alternative. The asymptotic properties of bootstrap approximation are investigated. Furthermore, for computational reasons, an approximation for the statistics, based on the number theoretic method, is suggested.

关键词： bootstrap approximation projection pursuit type statistic elliptical symmetry.

Suitability evaluation for land reclamation in mining area:A case study of Gaoqiao bauxite mine

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中国有色金属学会会刊：英文版 2011年第S3期21卷 506-515页

作者： WANG Shi-dong1, 2. LIU Chang-hua2. ZHANG He-bing2.1. College of Resources science and technology, {2. Normal University, {2. 100875, china 2. School of Surveying and Land Information Engineering, Henan Polytechnic University, Jiaozuo 454000, china College of Resources science and technology Beijing Normal University Beijing 100875 China School of Surveying and Land Information Engineering Henan Polytechnic University Jiaozuo 454000 China

Suitability evaluation plays an important role in land reclamation because the choice of evaluation methods affects the accuracy and objectivity of the suitability evaluation results. Furthermore, it influences the decision-making related to land reclamation. An improved method, which is called limit comprehensive conditions method, was developed after different suitability evaluation methods were studied. Based on this method, the reclaimed land of the Gaoqiao bauxite mining area was evaluated. The Gaoqiao mining area was divided into seven evaluation units that were evaluated respectively by selecting evaluation factors and establishing grade standards. The results show that the proposed method is more applicable and easier to handle. Moreover, its evaluation results are more scientific compared with the traditional evaluation methods. The improved method can be beneficial to the rapid monitoring and the effective management of reclaimed land in the opencast mine area.

关键词： mining area land reclamation suitability evaluation Gaoqiao bauxite mine