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Gnetifolin K, a New Stilbene Diglucoside from Gnetum parvifolium

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Chinese Chemical Letters 1997年第6期8卷 509-510页

作者： Xu, q Lin, M CHINESE ACAD MED SCI INST MAT MEDBEIJING 100050PEOPLES R CHINA BEIJIng UNION MED COLL BEIJING 100050PEOPLES R CHINA

A new stilbene diglucoside, gnetifolin K, was isolated from the lianas of Gnetum parvifolium. Its structure was established as isorhapotigenin-3,4'-di-O-beta-D-glucoside on the basis of spectral and chemical evidence.

关键词： Gnetifolin K a New Stilbene Diglucoside from Gnetum parvifolium

Optimizing 6-mercaptopurine and azathioprine therapy in the management of inflammatory bowel disease

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World Journal of Gastroenterology 2011年第37期17卷 4166-4173页

作者： Kara Bradford David q Shih Department of Medicine Cedars Sinai Medical Center Inflammatory Bowel and Immunobiology Research Institute Cedars-Sinai Medical Center

The thiopurine drugs,6-mercaptopurine(6-MP) and azathioprine,are efficacious in the arsenal of inflammatory bowel disease(IBD) *** reports indicate that 6-thioguanine nucleotide(6-TGN) levels correlate with therapeutic efficacy,whereas high 6-methylmercaptopurine(6-MMP) levels are associated with hepatotoxicity and *** to their complex metabolism,there is wide individual variation in patient response therein,both in achieving therapeutic drug levels as well as in developing adverse *** strategies to optimize 6-TGN while minimizing 6-MMP levels have been adopted to administer the thiopurine class of drugs to patients who otherwise would not tolerate these drugs due to *** this report,we will review different approaches to administer the thiopurine medications,including the administration of 6-mercaptopurine in those unsuccessfully treated with azathioprine;coadministration of thiopurine with allopurinol;co-administration of thiopurine with anti-tumor necrosis factor α;6-TGN administration;desensitization trials;and split dosing of 6-MP.

关键词： Azathioprine Drug levels Inflammatory bowel disease 6-Mercaptopurine Thiopurine

RESEARCH AND DEVELOPMENT OF HIGH TEMPERATURESTRUCTURAL MATERIALS FOR AERO-EngINE APPLICATIONS

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Acta Metallurgica Sinica(English Letters) 2005年第4期18卷 443-452页

作者： G. q. Zhang Beijing Institute of Aeronautical Materials （BIAM） Beijing 100095 China

The status of research, development of superalloys and materials processing ＆ fabrication technologies for aero-engine applications in China Aviation Industry, with an emphasis on recent achievements at BIAM including directionally solidified and single crystal superalloys for blade and vane applications, wrought superqlloys for aero-engine disks and rings, and powder metalurgy （PM） superalloys for high performance disk applications were described. It was also reviewed the development of new class of high temperature structural materials, such as structural intermetallics, and advanced material processing technologies including rapid solidification, spray forming and so on. The trends of research and development of the above mentioned superalloys and processing technologies are outlined. Cast, wrought and PM superalloys are the workhorse materials for the hot section of current aero-engines. New high temperature materials and advanced processing technologies have been and will be the subject of study. It is speculated that high performance, high purity and low cost superalloys and technologies will play key roles in aero-engines.

关键词： superalloy intermetallic materials processing aero-engine application

SEPARATION　CHARACTERISTICS　OF　THE　HYDROCYCLONE　WITH　A　CENTRAL　CONE　AND　ANNULAR　TEETH

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中国有色金属学会会刊：英文版 1996年第4期6卷 11-15页

作者： Chu, LY Chen, WM Luo, q NORTHEASTERN UNIV DEPT MINERAL ENGN SHENYANG 110006 PEOPLES R CHINA SICHUAN UNION UNIV DEPT CHEM PROC MACHINERY CHENGDU 610065 PEOPLES R CHINA

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关键词： ydrocyclone central cone annular teeth separation sharpness classification efficiency separation characteristics

First-principles Investigation of Bi Segregation at the Solder Interface of Cu/Cu_3Sn(010)

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Journal of Materials Science & Technology 2010年第12期26卷 1057-1062页

作者： X.Y. Pang Z.q. Liu S.q. Wang J.K. Shang Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China Department of Materials Science and Engineering University of Illinois at Urbana-Champaign IL 61801 USA

Density functional theory was employed to investigate the bismuth segregation at Cu/Cu3Sn（010） interface. Five initial constructions were introduced by adopting the adhesion energy criterion. Among them, the so-called ＂between-Cu＂ construction in which the interface Cu atoms of Cu slab locate along Cu-Cu bond direction in Cu3Sn slab was found to be the most energy-favored at an adhesion energy of 1.96 J/m^2. Based on this construction, five possible segregation sites were examined, and the most likely segregation site was determined with adhesion energy as low as 1.06 J/m^2, which was almost half of the initial one. Comparing with other sitest adhesion energies, it was concluded that size effect took a large part in embrittlement. The analyses of atomic structure and electronic density revealed that the slabs shifted away from interfaces due to bismuth segregation, and the atoms around Bi atom were Dressed away. This calculated work agreed aualitativelv with reported experimental results.

关键词： First-principles calculation Segregation Bismuth Interface SnBi solder

Stationary distributions for two-dimensional sticky Brownian motions:Exact tail asymptotics and extreme value distributions

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Science China Mathematics 2021年第11期64卷 2539-2562页

作者： Hongshuai Dai Yiqiang q.Zhao School of Statistics Shandong University of Finance and EconomicsJinan 250014China School of Mathematics and Statistics Carleton UniversityOttawaON K1S 5B 6Canada

Sticky Brownian motions can be viewed as time-changed semimartingale reflecting Brownian motions,which find applications in many areas including queueing theory and mathematical *** this paper,we focus on stationary distributions for sticky Brownian *** results obtained here include tail asymptotic properties in the marginal distributions and joint *** kernel method,copula concept and extreme value theory are the main tools used in our analysis.

关键词： sticky Brownian motion queueing model stationary distribution exact tail asymptotic kernel method extreme value distribution

Large Amplitude Low Frequency Waves in a Magnetized Nonuniform Electron-Positron-Ion Plasma

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Chinese Physics Letters 2004年第5期21卷 884-887页

作者： q.Haque H.Saleem Abdus-SalamInternationalCentreforTheoreticalPhysicsTrieste Italy Permanentaddresses:DepartmentofPhysics COMSATSInstituteofInformationTechnologyH-8IslamabadPakistan.

It is shown that the large amplitude low-frequency electromagnetic drift waves in electron–positron–ion plasmas might give rise to dipolar vortices. A linear dispersion relation of several coupled electrostatic and electromagnetic low-frequency modes is obtained. The relevance of this work to both laboratory and astrophysical situations is pointed out.

关键词： Positrons

Elastoplastic homogenization of particulate composites complying with the Mohr–Coulomb criterion and undergoing isotropic loading

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Acta Mechanica Sinica 2015年第3期31卷 392-405页

作者： D.Yang q.C.He School of Mechanical Engineering Southwest Jiaotong University Université Paris-Est Laboratoire Modélisation et Simulation Multi Echelle UMR 8208 CNRS

This work aims at determining the overall response of a two-phase elastoplastic composite to isotropic loading. The composite under investigation consists of elastic particles embedded in an elastic perfectly plastic matrix governed by the Mohr-Coulomb yield criterion and a non-associated plastic flow rule. The composite sphere assemblage model is adopted, and closed-form estimates are derived for the effective elastoplastic properties of the composite either under tensile or compressive isotropic loading. In the case when elastic particles reduce to voids, the composite in question degenerates into a porous elastoplastic material. The results obtained in the present work are of interest, in particular, for soil mechanics.

关键词： Composite Porous medium. Elastoplasticity Mohr-Coulomb yield criterion Non-associated flow rule Homogenization

An analysis of the chaotic motion of particles of different sizes in a gas fluidized bed

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Particuology 2008年第6期6卷 549-556页

作者： Y.q. Feng A.B. Yu Lab for Simulation and Modelling of Particulate Systems School of Materials Science and Engineering University of New South Wales Sydney NSW 2052 Australia

The dynamic behavior of individual particles during the mixing/segregation process of particle mixtures in a gas fluidized bed is analyzed. The analysis is based on the results generated from discrete particle simulation, with the focus on the trajectory of and forces acting on individual particles. Typical particles are selected representing three kinds of particle motion： a flotsam particle which is initially at the bottom part of the bed and finally fluidized at the top part of the bed; a jetsam particle which is initially at the top part of the bed and finally stays in the bottom de-fluidized layer of the bed; and a jetsam particle which is intermittently joining the top fluidized and bottom de-fluidized layers. The results show that the motion of a particle is chaotic at macroscopic or global scale, but can be well explained at a microscopic scale in terms of its interaction forces and contact conditions with other particles, particle-fluid interaction force, and local flow structure. They also highlight the need for establishing a suitable method to link the information generated and modeled at different time and length scales.

关键词： Fluidization Segregation Discrete particle simulation Granular dynamics