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Isotropic bodies and Bourgain's problem

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Science china Mathematics 2005年第5期48卷 666-679页

作者： HE Binwu & LENG Gangsong department of Mathematics, Shanghai university, Shanghai 2.0444, {2. 1. department of Mathematics Shanghai University 200444 Shanghai China

Let K (?) Rn be a convex body of volume 1 whose barycenter is at the origin, LK be the isotropic constant of K. Finding the least upper bound of LK , being called Bourgain's problem, is a well known open problem in the local theory of Banach space. The best estimate known today is LK 2.(?) K (?) r2.n2.(r1≥1/2. r2.(?)/2., then (?) ≤ (?) and find the conditions with equality. Further, the geometric characteristic of isotropic bodies is shown.

关键词： convex body isotropic body isotropic constant Bourgain’s problem spherical section function.

Atomic-scale computer simulation for early precipitation process of Ni75 Alx V2.-x alloy with intermediate Al composition

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Progress in Natural Science:Materials International 2005年第4期 64-70页

作者： ZHAO Yuhong 1*, JU Dongying 2. CHEN Zheng 3.* and HOU Hua 1(1. College of Material Science & Engineering, china North university, Taiyuan 03.051, china 2. department of Mechanical Engineering, Saitama Institute of Technology, Okabe, Saitama 3.9 02.9, Japan 3. Colledge of Materials Science & Engineering, Northwestern Polytechnical university, Xi'an 710072. china) College of Material Science & Engineering China North University Taiyuan 030051 China department of Mechanical Engineering Saitama Institute of Technology Okabe Saitama 369-0239 Japan Colledge of Materials Science & Engineering Northwestern Polytechnical University Xi' an 710072 China

The microscopic phase field approach is applied to model the early precipitation process of Ni 75 Al x V 2.- x alloy. Without any prior assumptions, this model can be used to simulate the temporal evolution of arbitrary morphologies and microstructures on atomic scale. By simulating the atomic pictures, and calculating the order parameters and volume fraction of the θ (Ni 3.) and γ′ (Ni 3.l) ordered phases, we study Ni 75 Al x V 2.- x alloys with Al composition of 0.05, 0.053.and 0.055 (atom fraction). Our calculated results show that, for these alloys, θ and γ′ phases precipitate at the same time; with the increase of Al content, the amount of γ′ phase increases and that of θ phase decreases; the precipitation characteristic of γ′ phase transforms from Non Classical Nucleation and Growth (NCNG) to Congruent Ordering + Spinodal Decomposition (CO+SD) gradually; otherwise, the precipitation characteristic of θ phase transforms from Congruent Ordering + Spinodal Decomposition (CO+SD) to Non Classical Nucleation and Growth (NCNG) mechanism gradually. Both θ and γ′ phases have undergone the transition process of mixture precipitation mechanism characterized by both NCNG and CO+SD mechanisms. No incontinuous transition of precipitation mechanism has been found.

关键词： computer simulation early precipitation mechanism phase field model Ni75Alx V2.-x alloy.

Altered subcellular distribution of nucleolar protein fibrillarin by actinomycin D in HEp-2.cells

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Acta Pharmacologica Sinica 2004年第7期25卷 56-60页

作者： Min CHEN2. Ping JIANG Research Center of Basic Medicine, School of Medicine, Jiangsu university, Zhenjiang 2.2.01, china Research Center of Basic Medicine School of Medicine Jiangsu University Zhenjiang 212001 Chin

AIM: To study the effects of actinomycin D on subcellular distribution of nucleolar protein fibrillarin in HEp-2.(human esophageal epithelial type 2. cells, and molecular mechanisms for maintenance of fibrillarin in nucleolus. METHODS: Indirect immunofluorescence assay was employed to investigate subcellular distribution of nucleolar protein fibrillarin and immunoblotting analysis was used to detect the total cellular amount of fibrillarin. RESULTS: Control cells with no drug treatment showed bright clumpy nucleolar staining, which indicated that fibrillarin decorated the nucleolus only. Treatment with actinomycin D caused dislocation of fibrillarin from nucleoli to nucleoplasm with numerous stained small nucleoplasmic entities. Immunoblotting showed that neither total cellular amount of fibrillarin nor the integrity of fibrillarin was changed upon the treatment. The dislocation of fibrillarin in cells treated at a lower concentration (0.05 mg/L) of actinomycin D, was totally reversible after removal of the drug from the medium. However, this reversion was not observed at a high drug concentration (1 mg/L). CONCLUSION: Actinomycin D induced dislocation of fibrillarin from nucleoli to nucleoplasm in HEp-2.cells. The retention of fibrillarin within the nucleolus was related to active RNA synthesis.

关键词： dactinomycin nuclear proteins fluorescence antibody technique immunoblotting

Study on Microstructure Refinement of Vanadium and Nitrogen Microalloyed Low Carbon Bainitic Steel

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Journal of Iron and Steel Research International 2011年第S1期18卷 355-359页

作者： GAO Fei 1,2.WANG Rui-zhen 1,QIAN Tian-cai 2.(1.china Central Iron and Steel Research Institute,Beijing 100081,china 2.Kunming {2. of Science and Technology,Kunming 650093.Yunnan,china) china Cent Iron & Steel Res Inst Beijing 100081 Peoples R China Kunming Univ Sci & Technol Kunming 650093 Yunnan Peoples R China

The effect of relaxation treatment after finish rolling on microstructure and mechanical properties has been investigated for a vanadium and nitrogen microalloyed low carbon bainitic *** lath bainite microstructure can be obtained in the plate with *** results of quantitative statistics show that in the plate without relaxation,80% of the total bainite lath bundles are in the range 5-15μm in length and 3.13.m in width,while in the plate with relaxation 80% of the total bundles are in the range 3.9μm in length and 1-7μm in *** mechanical properties show that the plate with relaxation has higher impact energy,yield strength and hardness than the plate without relaxation,also the comprehensive performance after tempered at 650℃ is superior to the plate without relaxation.

关键词： low carbon bainitic steel microstructure refinement V-N Microalloying

A new species: S(?)ea ( Cladophlebis ) henanense sp. nov. in Henan Province and its evolutional significance

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Chinese Science Bulletin 1997年第12期42卷 1023-1028页

作者： YANG Guanxiu, SHENG Axing and WANG Hongshanchina university of {2., Beijing {3. china

Oligocarpia and Chansitheca,which are subordinated to Gleicheniacea,were reported longago in the Permian of North *** and Taylor discovered several specimens of fertilefronds possessing gleicheniaceous characters in Funiushan Coalfield of Zhenjiang in *** characters are different from those of Oligocarpia and *** study on reproductive organs in situ,they established a new genus——Szea and as-

关键词： Middle Permian Gleicheniaceae Szea.

Infrared Spectra of La_(0.65)Ba_xMnO_(3.δ) Oxides

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Rare Metals 2001年第4期20卷 255-258页

作者： Jifan Hu1, Hongwei Qjn 1), Yanming Hao2. Yangxian Li2. Yizhong Wang3., Zhenxi Wan g3. 1) department of Physics, Shandong {3., Jinan 2.0100, {2. 2. School of Electronic Engineering and Material Science, Hehei {3. of Technology. Tianjing 3. Shandong Univ Dept Phys Jinan 250100 Peoples R China Hebei Univ Technol Sch Elect Engn & Mat Sci Tianjin 300130 Peoples R China Chinese Acad Sci Inst Phys Beijing 100080 Peoples R China

The infrared spectra of La_(0.65)Ba_xMnO_(3.|?￡(c) (x = 0.3., 0.3. and 0.3.) were investigated experimentally. The result shows that the sample La_(0.65)Ba_xMnO_(3.|?￡(c) has the largest Curie temperature and the smallest resistivity and wave number of the stretching vibration mode of MnO_6 octaheUron at 3.0 K among the investigated samples. However, the absorption strength for the stretching vibration mode of Mn0_6 octahedron in La_(0.65)Ba_xMnO_(3.|?￡(c) is stronger for parainagnetic phase than that for ferromagnelic phase, which may be connected with the reducing of the dynamic in- coherent Jahn-Teller distortion below Curie temperature. In addition, the large shift of wave number for the stretching mode at the temperatures from 2.3.to 42. K has been observed in La_(0.65)Ba_xMnO_(3.|?￡(c), which may be due to the in- crease of the Mn-O bond length with temperature increasing.

关键词： infrared spectra colossal magnetoresistance effect perovskite manganite stretching vibration mode Jahn-Teller distortion

MECHANISM AND APPLICATION OF COAL DRY BENEFICIATION WITH AIR-DENSE MEDIUM FLUIDIZED BED

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Journal of Central South university 1998年第2期10卷 27-30页

作者： Wei Lubin (department of Mineral Engineering, Central South university of Technology, Changsha 410083.{2.) department of Mineral Engineering Central South University of Technology Changsha 410083 China

The mechanism of beneficiation with air dense fluidized bed has been theoretically studied in the paper. Focusing attention on the misplacing resources in separation process, the misplacing effects are divided into two parts called respectively as misplacing effect of viscosity and misplacing effect of motion. The proposed separation theory can reasonably explain the results of separation in different fluidization states. Experimental results in pilot and commercial plants showed that the air dense medium fluidized bed is a high efficiency dry cleaning technique. The dynamic stability of fluidized bed density is directly affected by the variation of fine coal content in fluidized bed and can be controlled in expected range through measurement of fluidized bed density and adjusting of split flow rate. With air dense medium fluidized bed, various coals of size 50—6 mm can be efficiently beneficiated. The separation density can be adjusted between 1.2.2.2.g/cm 3. and the probable error E p value is about 0.06.

关键词： dry beneficiation air dense medium fluidized bed separation mechanism

The Practice Model and Optimization Strategy of the New-type Rural Social Old-age Insurance System

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学术界 2010年第7期 282-285页

作者： Yang Faxiang Sociology department,East china {2. of Science and Technology

Paragraph 1 Since 1986,the exploration of national rural social old-age insurance started. In 1991,based on the practicing on experimental units,the whole work was gradually launched.

关键词： type The Practice Model and Optimization Strategy of the New-type Rural Social Old-age Insurance System

Microstructure Study on Semi-solid 60Si2.n during Compressing

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Journal of university of Science and Technology Beijing 2001年第2期8卷 115-118页

作者： Yonglin Kang, Xiongfei Yang, Renbo Song, Weimin Mao, Maosheng Yang (Material Science & Engineering School, university of Science and Technology Beijing, Beijing 100083. {2.) Material Sci. and Eng. School University of Science and Technology Beijing 100083 China

The microstructure behavior and deformation mechanism of semi-solid 60Si2.n fabricated by electromagnetic stirring under different deformation conditions during thixoforming are studied by means of Gleeble-1500 thermal-strain-stress simulator. The micro- structure of deformed 60Si2.n and that of the non-deformed are compared. The results show that the grain size within deformation zone decreases as the amount of deformation increases or deformation temperature decreases, but deformation fate has small effect on grain size when the rate is very low. Besides, there is a critical amount of deformation to reduce grain size. These results offer theoretical and experimental basis for further producing semi-solid material with high melting temperature and direct forming of semi-solid slurry.

关键词： semi-solid microstructure grain size segregation, reduction