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A study on odd-parity high-lying states of the Sm atom with three-color resonant excitation

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science china(Physics,Mechanics & Astronomy) 2011年第6期54卷 1124-1130页

作者： LI Ming 1,2,DAI ChangJian 1,2 & XIE Jun 1,2 1 key laboratory of Display materials and Photoelectric Devices,Ministry of Education,tianjin 300191,china 2 School of science,tianjin university of technology,tianjin 300384,china key laboratory of Display materials and Photoelectric Devices Ministry of Education Tianjin China School of science Tianjin University of Technology Tianjin China

The odd-parity high-lying states of the Sm atom are investigated systematically by a three-color resonant excitation scheme with two different excitation *** two intermediate states,4f 6 6s7s 7 F 0 and 4f 6 6s7s 7 F 1 are employed for paths I and II,***-seven bound states are detected with paths I and II in the energy range between 44188 and 45515 cm 1,while 64 autoionizing states are found in the energy range from 45528 to 45761 cm *** only the level energies of all observed states,but also the line widths of autoionizing states are *** possible impact of configuration interaction on the line shape of autoionizing states is also *** addition,the total angular momentum is assigned uniquely to most of the states,whereas the information about the relative line intensity of all states is also presented.

关键词： high-lying states odd-parity the Sm atom resonant excitation

Effects of femtosecond laser ablation on the surface morphology and microstructure of a bulk TiCuPdZr glass alloy

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Rare Metals 2009年第3期28卷 272-276页

作者： WANG Hongshui LIANG Chunyong CHEN Xueguang WANG Lei YANG Yang YANG Jianjun ZHU Shengli LI Changyi School of materials science and Engineering Hebei University of Technology Tianjin 300130 China key laboratory of the Ministry of Education of china for Opto-electronic information science and technology Institute of Modem Optics Nankai University Tianjin 300071 China School of materials science and Engineering Tianjin University Tianjin 300072 China Stomatological Hospital Tianjin Medical University Tianjin 300070 China

The effects of femtosecond laser ablation on the surface characteristics and microstructure of a bulk TiCuPdZr glass alloy were investigated. The heat influence zone of femtosecond laser ablated with a laser energy of 100 μJ exhibits a ripple-like feather, while a porous structure appears on the surface of the specimen ablated by a 200 μJ femtosecond laser. The contents of Ti, Zr, and Pd on the ablated surface decrease and that of Cu increases with increasing laser energy. The crystallization process occurs on the glass alloy specimens during femtosecond laser ablation, and the crystallinity of a 100 μJ femtosecond laser-ablated specimen is greater than that of a 200 μJ femtosecond laser-ablated one.

关键词： femtosecond laser bulk glass alloy periodicity crystallization

Preparation of nanocrystalline BaTiO_3 ceramics

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science china(Technological sciences) 2009年第6期52卷 1730-1734页

作者： DENG XiangYun1,2,LI DeJun1,LI JianBao2,WANG XiaoHui3 & LI LongTu3 1 College of Physics and Electronic information,tianjin Normal university,tianjin 300387,china 2 materials and Chemical Engineering Institute,key laboratory for Hainan Advantage Resources and Applied technology in Chemical Engineering Material of Ministry of Education,Hainan Provincial key laboratory of Research on Utilization of Si-Zr-Ti,Hainan university,Haikou 570228,china 3 Department of materials science and Engineering,Tsinghua university,Beijing 100084,china College of Physics and Electronic information Tianjin Normal University Tianjin China materials and Chemical Engineering Institute Key Laboratory for Hainan Advantage Resources and Applied Technology in Chemical Engineering Material of Ministry of Education Hainan Provincial Key Laboratory of Research on Utilization of Si-Zr-Ti Hainan University Haikou China Department of materials science and Engineering Tsinghua University Beijing China

The high-dense nanocrystalline BaTiO3(BT)ceramics with grain size smaller than 100nm have been successfully prepared by the two step sintering and the spark plasma sintering(SPS)*** successive transitions in nanograin BT ceramics from rhombohedral to orthorhombic,tetragonal and cubic transitions,similar to those in coarse BT ceramics,were revealed by in-situ temperature dependent Raman *** multiphase coexistence and the diffused phase transition character were demonstrated in the 8nm nanocrystalline BT ceramics.

关键词： nanocrystalline BaTiO3 ceramics preparation microstructure size effect

Dominant point detecting based non-uniform B-spline approximation for grain contour

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science china(Technological sciences) 2007年第1期50卷 90-96页

作者： ZHAO XiuYang1, YIN YanSheng1,2 & YANG Bo3 1 Shandong key laboratory of Engineering Ceramics, Shandong university, Jinan 250061, china 2 School of materials, Ocean university of china, Qingdao 266003, china 3 State key laboratory of Advanced technology for materials Synthesis and Processing, Wuhan university of science and technology, Wuhan 430070, china Shandong key laboratory of Engineering Ceramics Shandong University Jinan China School of materials Ocean University of China Qingdao China State key laboratory of Advanced technology for materials Synthesis and Processing Wuhan University of Science and Technology Wuhan China

Three-dimension reconstruction from serial sections has been used in the last decade to obtain information concerning three-dimensional microstructural ge-ometry. One of the crucial steps of three-dimension reconstruction is getting compact and fairing grain contours. Based on the achievement of closed raw con-tours of ceramic composite grains by using wavelet and level set, an adaptive method is adopted for the polygonal approximation of the digitized raw contours. Instead of setting a fixed length of support region in advance, the novel method computes the suitable length of support region for each point to find the best es-timated curvature. The dominant points are identified as the points with local maximum estimated curvatures. Periodic closed B-spline approximation is used to find the most compact B-spline grain boundary contours within the given tolerance. A flexible distance selection approach is adopted to obtain the common knot vector of serial contours consisting of less knots that contain enough degrees of freedom to guarantee the existence of a B-spline curve interpolating each contour. Finally, a B-spline surface interpolating the serial contours is generated via B-spline surface skinning.

关键词： composite B-spline dominant points control points grain contour

In situ X-ray diffraction study of structural evaluation in Fe_(73)Cu_(1.5)Nd_3Si_(13.5)B_9 amorphous alloy at high temperature

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science china(Physics,Mechanics & Astronomy) 2008年第4期51卷 445-450页

作者： LI Gong,XU Tao,GAO YunPeng & LIU RiPing key laboratory of Metastable materials science and technology,Yanshan university,Qinhuangdao 066004,china key laboratory of Metastable materials science and technology Yanshan University Qinhuangdao China

The thermodynamics structural relaxation of Fe73Cu1.5Nd3Si13.5B9 amorphous alloy from room temperature to 400℃ has been investigated by measuring the structure factor with in situ X-ray diffraction. The structural information of the atomic con-figuration such as radial distribution function (RDF) and neighbor atomic distance was gained by Fourier transformation. The research result shows that the amor-phous structure remains stable in the temperature range of 30 to 400℃ but exhibits distinct changes in local atomic configuration with the increase of temperature. The quantitative determination of the neighbor atomic distance suggests that the de-gree of short-range order changes by the temperature altering the second nearest neighbor local atomic configuration of the amorphous when structural relaxation occurs.

关键词： Fe-based amorphous alloys in situ X-ray diffraction short-range order structure

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, china university of Mining and technology, Xuzhou 221116, china 2. Jiangsu key laboratory of Resources and Environmental information Engineering, china university of Mining and technology, Xuzhou 221116, china 3. State key laboratory of Geohazard Prevention and Geoenvironment Protection, Chengdu university of technology, Chengdu 610059, china 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 3240 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

Influence of reaction temperature on the formation process of ZnO quantum dots and the optical properties

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Optoelectronics Letters 2009年第1期5卷 1-5页

作者：庄晋艳李岚张晓松徐建萍魏军 Insititute of Material Physics Key Laboratory of Display Materials and Photoelectric DevicesMinistry of EducationTianjin Key Laboratory for Optoelectronic Materials and DevicesTianjin University of Technology Insititute of Material Physics Key Laboratory of Display Materials and Photoelectric Devices Ministry of EducationTianjin Key Laboratory for Optoelectronic Materials and DevicesTianjin University of Technology Colloge of information science Tianjin University of Technology Singapore Institute of Manufacturing technology

ZnO quantum dots (QDs)with the sizes of 3.0-5.6 nm are synthesized by solution-phase method at different temperatures. We find that temperature has great influence on the size of ZnO QDs. The growth process is the most sensitive to temperature, and the process is well explained by Lifshitz–Slyozov–Wagner (LSW) model. By photoluminescence (PL) spectra of the quantum dots at different temperatures and reactive time, we come to a conclusion that ultraviolet emission is mainly due to surface defects, and the or...

关键词： Electron mobility Emission spectroscopy Optical properties Semiconducting zinc compounds Surface defects Zinc oxide

Large second-order optical nonlinearities of s-triazine derivatives: View from micro molecules to macro crystals

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science china Chemistry 2005年第3期48卷 203-209页

作者： FANG Qi1, LEI Hong2, CUI Yuezhi3, HUANG Zhenli4, XUE Gang1 & YU Wentao1 1. State key laboratory of Crystal materials, Shandong university, Jinan 250100, china 2. School of information science and Engineering, Shandong university, Jinan 250100, china 3. Department of Chemical Engineering, Light Industry College of Shandong, Jinan 250100, china 4. key laboratory of Biomedical photonics, Ministry of Education, Huazhong university of science and technology, Wuhan 430074, china State key laboratory of Crystal materials Shandong University Jinan China School of information science and Engineering Shandong University Jinan China Department of Chemical Engineering Light Industry College of Shandong Jinan China key laboratory of Biomedical photonics Ministry of Education Huazhong University of Science and Technology Wuhan China

Three s-triazine derivatives have been synthesized and their structures been de-termined. These are Compound I: 2,4-dimethyl-6-(p-N,N-dimethylaminostyryl)-s-triazine (abbre-viated to NMe-1), Compound II: 2,4-dimethyl-6-(p-N,N-diethylaminostyryl)-s-triazine (to NEt-1), and Compound III: 2-methyl-4,6-bis(p-N,N-dimethylaminostyryl)-s-triazine (NMe-2). NMe-1 and NEt-1 molecules belong to the D-π-A type with a one-dimensional charge-transfer character. NMe-1 crystallizes to centrosymmetric P1 space group, while NEt-1 to non-centrosymmetric polar Cc space group with all of the molecular charge-transfer axes taking the same orientation. Under the irradiation of 1064 nm fundamental laser, NEt-1 powder crystals radiate a 2-order harmonic light with an intensity 46.8 times that of urea. The Λ typed NMe-2 molecule, which has a two-dimensional charge-transfer character, crystallizes to polar P21 space group. Its powder crystals exhibit a 2-order harmonic intensity 46.2 times that of urea. The quantum chemical cal-culations and tensor analyses have been carried out to reveal the dependence of the macro 2-order nonlinear optical (NLO) efficiency on the micro 2-order NLO coefficients (β) and on the crystalline packing styles.

关键词： s-triazine derivatives, synthesis, structure, SHG intensities of crystals, βvalues of molecules.

Level Set interface treatment and its application in Euler method

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science china(Physics,Mechanics & Astronomy) 2010年第2期53卷 227-236页

作者： WU KaiTeng1,2,HAO Li3,WANG Cheng4 & ZHANG Li1,2 1 Numerical Simulation Sichuan Higher School key laboratory,Neijiang Normal university,Neijiang 641112,china 2 College of Mathematics and information science,Neijiang Normal university,Neijiang 641112,china 3 College of science,Beijing university of Civil Engineering and Architecture,Beijing 100044,china 4 State key laboratory of Explosion science and technology,Beijing Institute of technology,Beijing 100081,china Numerical Simulation Sichuan Higher School key laboratory Neijiang Normal University Neijiang China College of Mathematics and information science Neijiang Normal University Neijiang China College of science Beijing University of Civil Engineering and Architecture Beijing China State key laboratory of Explosion science and technology Beijing Institute of Technology Beijing China

Level Set interface treatment method is introduced into Euler method,which is employed for interface treatment method for multi-materials. Combined with the ghost fluid method,the moving interface is tracked. Fifth-order WENO spatial discretization and third-order TVD Runge-Kutta time discretization methods are used. Shock-wave action on bubble,implosion and velocity field Shock effect bubbles; implosion and velocity field are simulated by means of LS-MMIC3D programmed by C++. Nu-merical results show that the Level Set interface treatment method is effective and feasible for multi-material interface treatment in comparison with the WENO method.

关键词： Euler method Level Set method shock-wave action on bubble implosion numerical simulation