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Acta Metallurgica Sinica(English Letters) 2004年第6期17卷 830-834页

作者： y.H.li J.Wang y.S.li y.KShan Dep.ofMaterialScienceandEngineering ShenyangLigongUmversityShenyang110168China InstituteofIndustry NingboPolytechnicNingbo315800China SchoolofMaterial＆ChemicalEngineering SouthernInstituteofMetallurgy＇Ganzhou341000China InstituteofMetalResearch TheChineseAcademyofSdencesShenyang110016China

Recrystallization behavior of a low carbon X70 pipeline steel was studied in the plane strain compression condition. It was found that the dynamic recovery but no dynamic recrystal- lization occurred in the current ex... 详细信息

关键词： pipeline steel, plane strain compression, recrystallization, austenite grain boundary

全球变暖背景下青藏高原北缘气候干湿变化模式的转型与机制——古气候视角

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中国科学：地球科学 2024年第6期54卷 1960-1979页

作者：李育张占森周雪如高铭君段俊杰薛雅欣尚好刘世瑜兰州大学西部环境教育部重点实验室兰州大学资源环境学院兰州730000

青藏高原北缘是季风西风协同影响的敏感区.夏季,水汽输送可以到达青海湖和祁连山东段;冬季,气候主要受控于西风.本文从古气候视角,对比了该区域中全新世暖期、中世纪暖期、现代暖期和未来百年暖期的干湿变化,发现中全新世暖期主要受轨... 详细信息

青藏高原北缘是季风西风协同影响的敏感区.夏季,水汽输送可以到达青海湖和祁连山东段;冬季,气候主要受控于西风.本文从古气候视角,对比了该区域中全新世暖期、中世纪暖期、现代暖期和未来百年暖期的干湿变化,发现中全新世暖期主要受轨道控制的东亚夏季风影响,区域整体表现出温暖湿润的气候特征;中世纪暖期主要受控于太阳辐射,存在暖干的现象;现代暖期和未来百年暖期主要由温室气体增加导致的温度升高控制,气候干旱化趋势显著.青藏高原北缘现代暖期和未来百年暖期的干湿格局与中世纪暖期类似,而持续升温会导致西风带扩张,气候逐渐湿润,未来干湿变化将与中全新世暖期更加相似.

关键词：青藏高原北缘干湿变化暖期相似驱动机制未来评估

A Safe and Brief Way for Preparing Anhydrous LnCl_3 (Ln=Sc, y, La to Lu)

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Rare Metals 2000年第2期19卷 157-161,152页

作者： li, y Wang, LS Wang, yH Department of Chemistry Northeastern University Shenyang 110006 China

Anhydrous lanthanide chlorides LnCl 3 (Ln=Sc, y, La to Lu except for Pm), which are difficult to prepare in other ways, were prepared by chemical vapor transport (CVT) process. Rare earth oxide reacted with Al 2Cl 6 at 300℃ to produce LnCl 3, which was then separated from other solids by means of CVT at a temperature gradient from 400 to 180℃. Residual Al 2Cl 6 (g) was removed by carrier of dry N 2 gas at 200℃. The yielding rates were >90%, and the purity of products was >99.5%.

关键词： Anhydrous lanthanide chlorides AlCl 3 Chemical vapor transport

COUPLED SIMULATION OF 3D ELECTRO-MAGNETO-FLOW FIELD IN HALL-HEROULT CELLS USING FINITE ELEMENT METHOD

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Acta Metallurgica Sinica(English Letters) 2006年第2期19卷 105-116页

作者： J. li W. liu y.Q. Lai Q.y. li y.X. liu School of Metallurgy Science and Engineering Central South University Changsha 410083 China Chemistry Department Guangxi Normal University Guilin 531400 China

Two full 3D steady mathematical models are developed by finite element method （FEM） to calcalate coupled physics fields. the electro-magnetic model is built and solved first and so is the fluid motion model with the acquired electromagnetic force as source body forces in Navier-Stokes equations. Effects caused by the ferromagnetic shell, busbar system around, and open boundary problem as well as inside induced current were considered in terms of the magnetic field. Furthermore, a new modeling method is found to set up solid models and then mesh them entirely with so-called structuralized grids, namely hex-mesh. Examples of 75kA prebaked cell with two kinds of busbar arrangements are presented. Results agree with those disclosed in the literature and confirm that the coupled simulation is valid. It is also concluded that the usage of these models facilitates the consistent analysis of the electric field to magnetic field and then flow motion to the greater extent, local distributions of current density and magnetic flux density are very much dependent on the cell structure, the steel shell is a shield to reduce the magnetic field and flow pattern is two dimensional in the main body of the metal pad.

关键词： coupled simulation electromagnetic field flow field aluminum reduction cell finite element analysis

Accelerated Approach to the Synthesis of Fluoriated Polyether Dendrimers

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Chinese Chemical Letters 1998年第9期9卷 809-812页

作者： Cao, XP li, XH Chow, HF li, y Lanzhou Univ Natl Lab Appl Organ Chem Lanzhou 730000 Peoples R China Chinese Univ Hong Kong Dept Chem Shatin NT Hong Kong

Fluorinated polyether dendritic sectors 4, 7 and 10 from the first to the third generations, respectively, were prepared by a convergent approach from readily available pentafluorophenol, phloroglucinol and 1,3-dibromopropane. These dendritic sectors have good solubility properties and are stable in both acidic and basic media. Hence they are useful dendritic building blocks for the preparation of functional dendrimers.

关键词： synthesis fluoriated polyether dendrimers

Nanotexturing and Wettability Ageing of Polypropylene Surfaces Modified by Oxygen Capacitively Coupled Radio Frequency Plasma

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Journal of Materials Science & Technology 2014年第10期30卷 965-972页

作者： y.P.li M.K.Lei Surface Engineering Laboratory School of Materials Science and EngineeringDalian University of Technology

Polypropylene （PP） was treated by an oxygen capacitively coupled radio frequency plasma （CCP） under a radio frequency （RF） power of 200 W for exposure time of 1, 5, and 10 rain. The ageing process of the plasma- treated PP was studied at an ageing temperature of 90 ~C during an ageing time up to 25 h. The formation of the nanotextures with different geometry and aspect ratio and the grafting of large number of oxygen- containing groups were achieved on as-treated PP surfaces under the oxygen CCP treatment for the increased exposure time. The hydrophilicity on the as-treated PP surfaces with the stable nanotextures was rapidly depressed during the ageing process at 90 ℃ due to the restructuring of chemical composition. The surface restructuring rate was dependent on the aspect ratio and the oxygen-containing groups on the nanotextured PP with increasing exposure time. The hydrophobic over-recovery to high hydrophobicity and superhydrophobicity were observed on the post-aged surfaces with the stable nanofibrils from as-treated hydrophilic surfaces. The superhydrophobicity with the low water adhesion was achieved on the post-aged surfaces preserving the nanofibrils with high aspect ratio and large distance due to the decrease of the oxygen-containing groups after the surface restructuring.

关键词： Polypropylene Plasma nanotexturing Ageing Surface restructuring Superhydrophobicity

THE MICROSTRUCTURAL BANDING IN THE CENTER OF HOT ROLLLNG STRIP

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Acta Metallurgica Sinica(English Letters) 2005年第5期18卷 664-668页

作者： C.L. Mo y. T. Zhang D.Z. li y. y. li Institute of Metal Research The Chinese Academy of Sciences Shenyang 110016China Shenyang ligong University Shenyang 110168 China

The microstructural banding in steels is often found in hot rolling strips, which plays a very important role in mechanical properties. Much work has been done to investigate how the microstructural banding is formed during hot rolling. In the present study, the microstructure of hot rolling strips was examined in term of optical microscopy and transmission electron microscopy. Electron probe microanalysis was also used to decide the distribution of microchemical bands, by this means, the phases in these strips were found to be ferrite and pearlite. The average distance between the carbon lamellas in pearlite is about 0.06-0.1μm. It is also shown that microstructural banding in hot rolled carbon steel was closely related to the segregation of manganese and silicon into those bands. Based on the transformation kinetic, the simulated results pointed out that the thermodynamic stability of austenite would increase with the increasing of Mn, which led to a decrease of ferrite growth rate. The effect of Mn on the decomposition of austenite is attributed to segregation of Mn atoms along the ferrite/austenite phase boundary which causes a strong solute drag effect. The addition of Mn to steel decreases the activity of austenite, thereby it is beneficial to the formation of non-equilibrium phase, such as degenerate pearlite. The formation of banded structure on the hot rolled process was discussed.

关键词： pearlite ferrite microstructural banding hot rolling strip

Photoisomerization of norbornadiene group in a rigid bichromophoric compound initiated by remote keto chromophore: long-distance through-bond triplet energy transfer

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Chinese Journal of Chemistry 1996年第4期14卷 377-380页

作者： Tung, CH Zhang, LP li, y CHINESE ACAD SCI INST PHOTOG CHEMBEIJING 100101PEOPLES R CHINA

A diad compound 3 beta(bicyclo[2,2,1]hepta-2,5-diene-2-methylcarboxylate-3-carboxy)-androst-5-en-17-one (NBD-S-ONE) was synthesized and its photochemistry was examined. Irradiation of NBD-S-ONE in acetonitrile at lambda > 300 nm selectively excited the keto chromophore. After intersystem crossing, the triplet energy of the keto group was transferred to the NBD group with 18.6% efficiency via a through-bond mechanism, resulting in the isomerization of the latter group to the quadricyclane group.

关键词： norbornadiene photoisomerization through-bond triplet energy transfer

HCV genotypes in hepatitis C patients and their clinical significances

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World Journal of Gastroenterology 1999年第6期5卷 547-549页

作者： Huang F Zhao GZ li y China Med Univ Affiliated Hosp 2 Dept Infect Dis Shenyang 110003 Liaoning Prov Peoples R China

INTRODUCTIONIt has been discovered that hepatitis C virus (HCV) presents considerable nucleotide variation and has many genotypes. At least twelve, 5 of which prevalent, i.e.: Ⅰ/1a, Ⅱ/1b, Ⅲ/2a, Ⅳ/2b, and Ⅴ/3a types. The different genotypes of HCV may possess some retationship with regional distribution, clinical manifestation, response to treatment and prognosis of HCV infection, thus to study the genotypes of HCV further in different areas is of practical value. We detected HCV genotypes in 94 patients with hepatitis C and in 6 patients with primary hepatocarcinoma by PCR assay with four kinds of type-specific primers with a view to study the distribution of HCV genotypes in hepatitis C in Shenyang area and their clinical significances.

关键词： hepatitis C hepatitis C virus genotyping

Dielectric Behavior of Middle Phase Microemulsion

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Chinese Chemical Letters 2000年第8期11卷 739-742页

作者： Lei, JP li, y Zhao, KS S China Normal Univ Dept Chem Guangzhou 510631 Peoples R China

Dielectric measurements were performed on middle phase microemulsions composed of sodium dodecylsulfate(SDS), cetyltrimethylammonium bromide(CTAB), n-butanol, n-heptane and brine. Distinct and unique dielectric behavior, with characteristic frequency dependence regularity on the salinity of the microemulsions, was observed in the low-frequency range from 10-10(3)Hz. It can be considered to be an interfacial polarization mechanism.

关键词： middle phase microemulsions dielectric spectroscopy relaxation time