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The mathematical model of wetting angle of heterogeneous nucleation

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Science china(Technological Sciences) 2004年第4期47卷 391-397页

作者： HUANG Cheng1, SONG Bo1, MAO Jinghong2.& ZHAO Pei3.1. School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083. china 2. School of Material Science, University of Science and Technology Beijing, Beijing 100083. china 3. Central Iron and Steel Research {2., Beijing 100081, china 1. School of Metallurgical and Ecological Engineering University of Science and Technology Beijing 100083 Beijing China 2. School of Material Science University of Science and Technology Beijing 100083 Beijing China 3. Central Iron and Steel Research institute 100081 Beijing China

The heterogeneous nucleation has been analyzed in terms of the thermodynamic theory, and the mathematical model of wetting angle of heterogeneous nucleation has been developed based on the dynamic requirements of hetero- and homogeneous nucleation. With the wetting angel model, the wetting angles of different catalysts in liquid iron have been calculated. The result shows that the wetting angle of most catalysts is smaller than 40, and the value of f() is far less than 1. The wetting angles of TiN, TiC and RE2.3.are smaller, while the wetting angle of MnO is bigger among the ordinary nucleation catalysts. The wetting angles calculated by this model are in agreement with the results of other research work.

关键词： heterogeneous nucleation, mathematical model, wetting angle, undercooling.

The reconstruction and interpretations of lake status at 6 ka and 18 ka *** inland mainland Asia

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Chinese Science Bulletin 1998年第14期43卷 1145-1157页

作者： QIN Boqiang 1, SHI Yafeng 1 and YU Ge 2. 3.1. Nanjing institute of Geography & Limnology, Chinese Academy of Sciences, Nanjing 2.0008, {3. 2. Dynamic Palaeoclimatology, Lund University, PO Box 117, S 2.1 00, Lund, Sweden 3. Department of Nanjing institute of Geography & Limnolagy Chinese Academy of Sciences Nanjing China Dynamic Palaeoclimatology Lund University Lund Sweden Department of Geology and Ocean Sciences Nanjing University Nanjing China

By means of survey of literature through compilations of sedimentological, biogeological and geomorphologic data, the inland lake level changes in arid or semi arid mainland Asia at 6 and 18 ka B.P. have been reconstructed. The results showed that the lakes from western and northwestern Asia were characterized by very high water levels at 18 ka B.P., but low or intermediate water stands at 6 ka B.P. The high lake level in this region was associated with the southward displacement of westerlies, therefore, the extent of the high lake stand indicated the southern flank of westerlies during the glaciation. Conversely, the lakes from the eastern and southern Asia registered comparative low levels at 18 ka B.P. and significantly high one at 6 ka B.P. The lowering of lake level at 18 ka B.P. was caused by the weakened summer monsoon and the high lake level at 6 ka B.P. by the enhanced summer monsoon induced by the enlarged thermal contrast between land and ocean. The extent of high lake levels indicated the northern boundary of monsoon expansion. Between the above two regions, there is a climatic transitional zone in the Central Asia where the lake behavior was close to that in southeastern Asia at 6 ka B.P. but became similar to that in northwestern Asia at 18 ka B.P. Thus this zone became a transitional sector from the monsoon to the westerlies.

关键词： lake status inland mainland Asia westerlies monsoon.

Some properties on multivariate filter banks with a matrix factorization

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Progress in Natural Science:Materials International 2005年第2期15卷 20-30页

作者： LIAN Qiaofang1, XIAO Hongying2. and CHEN Qiuhui3.1. Department of Mathematics, Beijing Jiaotong University, Beijing 100044, china 2. {3. of Mathematics, Academy of Mathematics and System Sciences, Chinese Academy of Sciences, Beijing 100080, china 3. Department of Scientific Computing and Computer Applications, Zhongshan University, Guangzhou 5102.5, china) Department of Mathematics Beijing Jiaotong University Beijing 100044 China. institute of Mathematics Academy of Mathematics and System Sciences Chinese Academy of Sciences Beijing 100080 China. Department of Scientific Computing and Computer Applications Zhongshan University Guangzhou 510275 China

A class of multivariate filter banks with a matrix factorization has been developed by Chen et al. The main purpose of this paper is to discuss some further properties of this kind of filter bank, such as the completeness, accuracy of the corresponding scaling functions and the relationships with Daubechies' wavelets and the multi-wavelets provided by Chui and Lian. Moreover, some examples are given to show that this kind of filter bank has a higher accuracy for the scaling functions.

关键词： filter banks completeness accuracy matrix factorization

Simulation study of phase retrieval for hard X-ray in-line phase contrast imaging

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Science china(Physics,Mechanics & Astronomy) 2005年第4期48卷 450-458页

作者： YU Bin1,2. PENG Xiang1,2. TIAN Jindong1, NIU Hanben1, DIAO Luhong3.& LI Hua3.1. Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education, institute of Optoelec- tronics, Shenzhen University, Shenzhen 518060, {3. 2. State Key Laboratory of Precision Measuring Technology and Instruments, Tianjin University, Tianjin 3.0072.{3. 3. Key Laboratory of Intelligent Information Processing, institute of Computing Technology, Chinese Academy of Sciences, Beijing 100080,{3. 1. Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education Institute of Optoelectronics Shenzhen University 518060 Shenzhen China 2. State Key Laboratory of Precision Measuring Technology and Instruments Tianjin University 300072 Tianjin China 3. Key Laboratory of Intelligent Information Processing Institute of Computing Technology Chinese Academy of Sciences 100080 Beijing China

Two algorithms for the phase retrieval of hard X-ray in-line phase contrast imaging are presented. One is referred to as Iterative Angular Spectrum Algorithm (IASA) and the other is a hybrid algorithm that combines IASA with TIE (transport of intensity equation). The calculations of the algorithms are based on free space propagation of the angular spectrum. The new approaches are demonstrated with numerical simulations. Comparisons with other phase retrieval algorithms are also performed. It is shown that the phase retrieval method combining the IASA and TIE is a promising technique for the application of hard X-ray phase contrast imaging.

关键词： X-ray optics, phase contrast imaging, phase retrieval, angular spectrum, hard X-ray.

Discovery of seep carbonate nodules as new evidence for gas venting on the northern continental slope of South china Sea

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Chinese Science Bulletin 2006年第10期51卷 1228-1237页

作者： CHEN Zhong1,2.3. YAN Wen1,2.3. CHEN Muhong1,3. WANG Shuhong1,2.3. LU Jun1,3. ZHANG Fan1,3. XIANG Rong1,3. XIAO Shangbin1,3. YAN Pin1,2.3.& GU Senchang1,2.3.1. South china Sea institute of Oceanology, Chinese Academy of Sci-ences, Guangzhou 5103.1, china 2. Guangzhou Center for Gas Hydrate Research, Chinese Academy of Sciences, Guangzhou 5103.1, china 3. Key Laboratory of Marginal Sea Geology, South china Sea institute of Oceanology and Guangzhou institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 5103.1, china South china Sea institute of Oceanology Chinese Academy of Science Guangzhou China Guangzhou Center for Gas Hydrate Research Chinese Academy of Sciences Guanzhou China Key Laboratory of Marginal Sea Geology South China Sea Institute of Oceanology and Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou China

Seep carbonate nodules were firstlycollected from the southwestern Dongsha area onnorthern continental slope of South china Sea formineralogical and geochemical studies. The resultsof X-ray diffraction show that carbonate nodules arecomposed of Fe-rich domolite,siderite and a few cal-cite and aragonite, as well as a small quantity ofnon-carbonate minerals such as goethite, quartz andclay minerals. Fe-rich dolomite and siderite charac-terized by euhedral microcrystalline structure weredirectly precipitated at cold seeps. The δ 13. valuesfor Fe-rich dolomite and siderite in the bulk nodulesvary from ?18.2.‰ to ?3..07‰, and the δ 18O valuesrange from 0.42.to 2.76‰. Their moderate depleted13. reflects that carbon origin is possibly thermoge- netic gas or mixed gas, which is evidence of gasventings in the seafloor. Moreover, massive wormtube fossils related to cold seeps were found on thesurfaces of carbonate nodules, and the conduitsand/or channels in semi-solidified nodules whichwere not filled by carbonate or sediment were alsoobserved. A preliminary conclusion is that activemicro gas venting with a conduit/channel diameterrange from 2.0 μm to 600 μm possibly exists inmodern seafloor of the carbonate nodule area.

关键词：渗出碳酸盐节碳氧同位素甲烷渗漏天然气水化物

Effective solutions to a global 3. visual system in networking environments

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Science china Earth Sciences 2005年第11期48卷 2032-2039页

作者： ZHANG Liqiang1,2. ZHANG Yan3. YANG Chongjun2. LIU Suhong1, REN Yingchao2. RUI Xiaoping2.& LIU Donglin2.1. State Key Laboratory of Remote Sensing Sciences, School of Geography and Remote Sensing, Beijing Normal University, Beijing 100875, china 2. State Key Laboratory of Remote Sensing Sciences, institute of Remote Sensing Applications, Chinese Academy of Sciences, Beijing 101001, china 3. institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 101001, china 1. State Key Laboratory of Remote Sensing Sciences School of Geography and Remote Sensing Beijing Normal University 100875 Beijing China 2. Chinese Academy of Sciences State Key Laboratory of Remote Sensing SciencesInstitute of Remote Sensing Applications 101001 Beijing China 3. institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences 101001 Beijing China

The development of Web-based global 3. visual system has made progresses. However, there exist few mature and effective ways for managing, transmitting and visualizing massive spatial data. Based on the related work, the paper illustrates the ellipsoidal quadtree technique for rapid access multi-scale and multiple level geographical data, integrates the streaming with level-of-detail rendering method for transmitting the data on the network, and im-plements large-scale terrain surface simplification using M-band wavelet transforms and mul-tiresolution triangulations. We fulfil a web-based global terrain visual system using COM com-ponents on the basis of the above techniques. The system has a good prospect in the military simulation and city plans.

关键词： massive spatial data, streaming transmission, system architecture, M-band wavelet

Approaches to improving critical current density of YBCO superconducting thick films deposited by electrophoresis

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Science china(Physics,Mechanics & Astronomy) 2004年第2期47卷 165-172页

作者： ZHU Yabin1,2. ZHOU Yueliang2. LIU Zhen2. WANG Shufang2. CHEN Zhenghao2. L?Huibin2. YANG Guozhen2. XIAO Ling3. REN Hongtao3. JIAO Yulei3.& ZHENG Minghui3.1. Department of Physics, College of Science, Beijing Jiaotong University, Beijing 100044, china 2. Laboratory of Optical Physics, institute of Physics and Center for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100080, china 3. General Research institute for Nonferrous Metals, Beijing 100088, china Correspondence should be addressed to Zhu Yabin (email: ybzhu@***) 1. Department of Physics College of Science Beijing Jiaotong University 100044 Beijing China 2. Laboratory of Optical Physics institute of Physics and Center for Condensed Matter Physics Chinese Academy of Sciences 100080 Beijing China 3. General Research institute for Nonferrous Metals 100088 Beijing China

Fabrication of YBCO superconducting thick films by electrophoresis has been widely reported. However, the value of critical current density (J c) is far from what the practical application requires. The superconducting thick films are obtained using top-seeded melt growth method with different proportional Y2.aCuO5 (Y2.1) addition. High-pressure oxygen has been used in the annealing process to improve the uniformity of the oxygen content in the superconducting thick films. When 40mol% Y2.1 powder is added to the YBa2.u3.7–5 (Y12.) powder,J c for the superconducting thick film by approaches described above reaches 7.008×103.A/cm2.(77 K, 0 T), which is greater than the value ever reported.

关键词： YBCO thick films, electrophoretic deposition, melt-textured.

Effect of excess Y_2._3.addition on the physical properties of melt processed YBCO bulks

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Science china(Physics,Mechanics & Astronomy) 2004年第1期47卷 17-23页

作者： YANG Wanmin1,2.3. ZHOU Lian2. FENG Yong2. ZHANG Pingxiang2. WU Minzhi3.& W. GAWALEK3.1. Department of Physics, Shaanxi Normal University, Xi抋n 710062. china 2. Northwest institute for Nonferrous Metal Research. Xi抋n 710016, china 3. institute fur Physikalische Hochtechnologie e.V(IPHT), Jena, Germany Correspondence should be addressed to Yang Wanmin (email: wm-yang@***) Received June 2., 2.03 1. Department of Physics Shaanxi Normal University 710062 Xi’an China 2. Northwest institute for Nonferrous Metal Research 710016 Xi’an China 3. institute fur Physikalische Hochtechnologie e.V (IPHT) Jena Germany

The YBCO superconductors with Y2.3.addition were prepared by a modified melt textured process and the effects of excess Y2.3.addition on the physical properties of melt textured YBCO have been investigated. It is found that the melt temperature of YBCO samples decreases drastically with the increasing Y2.3. and the maximum levitation forces are drastically different for samples with different Y2.3.addition. It is also found that the optimal Y2.3.addition to YBCO is about 10wt%. Considering the microstructure and the starting composition, the results are well discussed and interpreted.

关键词： YBCO superconductor, melt growth, Y2.3 addition, levitation force.

Comparison study of trapped water in human erythrocytes by EPC and DSC method and its application

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Science china(Technological Sciences) 2004年第3期47卷 343-351页

作者： ZHAO Gang1, HE Liqun1, GUO Xiaojie2. LIU Zhong3. LUO Dawei1,3.& GAO Dayong1,3.1. Cryobiomedical Engineering Research institute, Department of Thermal Science and Energy Engineering, University of Science and Technology of china, Hefei 2.002., china 2. Red Cross Blood Center of Hefei, Hefei 2.002., china 3. Department of Mechanical Engineering, University of Kentucky, Lexington, KY 40506-0108, USA Univ Sci & Technol china Cryobiomed Engn Res Inst Dept Thermal Sci & Energy Engn Hefei 230027 Peoples R China Red Cross Blood Ctr Hefei Hefei 230022 Peoples R China Univ Kentucky Dept Mech Engn Lexington KY 40506 USA

The novel differential scanning calorimetry method for determining trapped water volume of human red blood cell during freezing process has been reexamined. Results show that the final erythrocyte volume is 53. of its isotonic volume after freezing to -40℃. An electronic particle counter (MultisizerTM III, Beckman Coulter Inc., USA) was used to measure cell volume changes in response to hypertonic solution. Using this approach, when extracellular solution was 3.86 mOsm, the equilibrium cell volume was found to be 57% of its isotonic value. Both results indicate that 3.%—40% of intracellular water is trapped and cannot respond to osmotic difference between intra- and extracellular solution. These findings are consistent with the published data: at least 2.%—3.0} of the isotonic cell water volume is retained within RBCs during freezing. Some applications of the values of trapped water are addressed.

关键词： differential scanning calorimeter/DSC, electronic particle counter/EPC, cell volumetric change, red blood cell/RBC/erythrocyte