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ON NEVANLINNA DIRECTIONS OF ALGEBROID FUNCTIONS

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Acta Mathematica Scientia 2005年第2期25卷 367-375页

作者：卢谦顾永兴 College of sciences Southwest University of science and Technology Mianyang 621010China College of Mathematic SciencesSichuan UniversityChengdu 610064China College of Mathematics and sciences Chongqing University Chongqing 400044China

In this paper, a notation delta(x)(w) is derived from the counting function N-x(r, w) of branch points of algebriod functions. With this notation, the authors give the definition of the Nevanlinna direction for algebriod functions and discuss its existence in certain condition. By this notation the authors also obtain the numbers of exceptional value of the Julia direction and Borel direction of algebriod functions are not more than 2 + [delta(x) (w)] here [x] implies an maximum integer number which does not exceed x.

关键词： Algebriod functions deficient relations Nevanlinna directions

Enhancement in Magnetorheological Effect of Magnetorheological Elastomers by Surface Modification of Iron Particles

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Chinese Journal of Chemical Physics 2008年第1期21卷 87-92页

作者： Wan-quan Jiang Jing-jing Yao Xing-long Gong Lin Chen Department of Chemistry University of Science and Technology of China Hefei 230026 China CA5 Key Laboratory of Mechanical Behavior and Design of Materials Department of Mechanics andMechanical Engineering University of Science and Technology of China Hefei 230027 China

In order to obtain magnetorheological （MR） elastomers with high magnetorheological effect, a family of anisotropic rubber-based MR elastomers was developed using a new form of chemical modification. Three different kinds of surfactants, i.e. anionic, nonionic and compound surfactants, were employed separately to modify iron particles. The MR effect was evaluated by measuring the dynamic shear modulus of MR elastomer with a magneto-combined dynamic mechanical analyzer. Results show that the relative MR effect can be up to 188% when the iron particles are modified with 15% Span 80. Besides the surface activity of Span 80, however, such high modifying effect is partly due to the plasticizing effect of Span 80. Compared with the single surfactant, the superior surface activity of compound surfactant makes the relative MR effect reach 77% at a low content of 0.4%. Scanning electron microscope observation shows that the modification of compound surfactant results in perfect compatibility between particles and rubber matrix and special self-assembled structure of particles. Such special structure has been proved beneficial to the improvement of the relative MR effect.

关键词： Magnetorheological elastomers Shear modulus Surfactant Microstructure

MECHANISM FOR PHOTOSTIMULATED LUMINESCENCE (PSL) OF BaFX: Eu2^+

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维普期刊数据库

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Chinese Chemical Letters 1992年第11期3卷 929-932页

作者： Mian Zeng SU Wei ZHAO Wei CHEN Department of Chemistry Peking UniversityBeijing 100871

Some new photostimulable F centers in the X-rayed BaFX: Eu2^+ were found. Their absorption bands are located in IR region. PSL process of X-rayed BaFX:Eu^(2+) consists of two subordinated process—e^--h^+ recombination and radiative transition of Eu2^+ ions. The latter is a slow and rate-determining step. Dynamics and mechanism of that PSL have been investigated.

关键词： Eu2 MECHANISM FOR PHOTOSTIMULATED LUMINESCENCE OF BaFX PSL

Microstructures and tensile properties of as-cast Mg-5Sn-1Si magnesium alloy modified with trace elements of Y,Bi,Sb and Sr

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china Foundry 2021年第1期18卷 9-17页

作者： He-shuai Yu Xue-feng Guo Hong-bao Cui School of Materials science and Engineering Henan Polytechnic UniversityJiaozuoHenan454000China Henan International Joint Research Laboratory for High-Performance Light Metallic Materials and Numerical Simulations Henan Polytechnic UniversityJiaozuoHenan454000China

The microstructures and mechanical properties of as-cast Mg-5 Sn-1 Si magnesium alloy modified with trace elements Y,Bi,Sb and Sr were investigated and *** show that the microstructure of the as-cast Mg-5 Sn-1 Si alloy consists ofα-Mg,Mg_(2) Si,Mg_(2) Sn and Mg_(2)(Si_xSn_(1-x))*** adding 0.8 wt.%Y,0.3 wt.%Bi,0.9 wt.%Sb and 0.9 wt.%Sr,respectively into the Mg-5 Sn-1 Si magnesium alloy,Mg_(24)Y_(5),Mg_(3) Bi_(2),Mg_(3) Sb_(2) and Mg_(2) Sr phases are precipitated *** elements can refineα-Mg grain and Chinese scriptshaped Mg_(2) Si *** efficiency of different trace elements onα-Mg grain and Mg_(2) Si phase is *** element has the best refinement effect,followed by Sb and Bi,while Y has the least refinement ***-5 Sn-1 Si-0.9 Sr alloy has higher tensile properties than the other three modified *** refinement mechanism of Y,Bi and Sr elements on Mg-5 Sn-1 Si magnesium alloy can be explained by the growth restriction factors and the solute *** Mg-5 Sn-1 Si-0.9 Sb alloy,the heterogeneous nuclei of Mg_(3) Sb_(2) phase is the main reason for the refinement of grains and second phases.

关键词： magnesium alloy Mg-5Sn-1Si alloy Y Bi Sb Sr Mg2Si phase

Significant relationship between spring AO and the summer rainfall along the Yangtze River

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Chinese science Bulletin 2002年第11期47卷 948-951页

作者： GONG Daoyi ZHU Jinhong WANG Shaowu Laboratory of Environmental Change and natural Disaster Institute of Resources ScienceBeijing Normal UniversityBeijing 100875China Department of Atmospheric sciences Peking UniversityBeijing 100871China

The influence of spring AO on the summer rainfall along the Yangtze River is investigated. The long-term rainfall observations are filtered to remove the low-frequency variations longer than 10 years. The inter-annual components show a high correlation to AO in the last hundred years. The strongest correlation appears for May AO and summer rainfall with a value of -0.39, significant above the 99% confidence level. Associated with one standard deviation stronger May AO index, the rainfall over the Yangtze River to the southern Japan decreases by about 3%-9%, while, at the same time increases by about 3%-6% in the northern china and far-eastern Russia. The coherent changes in rainfall are significantly related to the East Asian summer jet stream in the upper troposphere. When there is stronger AO in spring, the jet stream tends to move polarward in summer, and leads the rainfall-belt to move northward too. That gives rise to a drier condition in the Yangtze River valley, wetter anomalies in northern china.

关键词： Yangtze River precipitation Arctic Oscillation (AO).

Phosphine oxide directing-group-enabled atroposelective C-H bond acyloxylation via an eight-membered palladacycle intermediate

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Chinese Chemical Letters 2023年第5期34卷 277-280页

作者： Peng-Bo Bai Ming-Ying Wu Xin-Xin Yang Gang-Wei Wang Shang-Dong Yang State Key Laboratory of Applied Organic Chemistry Lanzhou UniversityLanzhou 730000China State Key Laboratory for Oxo Synthesis and Selective Oxidation Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China

Herein,we report the first atroposelective C(sp^(2))-H bond acyloxylation enabled by a phosphine oxide directing ***,this transformation is shown to proceed through an eight-membered palladacycle intermediate,as opposed to the kinetically and thermodynamically favored five-membered palladacycle ***,L-pGlu-OH,a cheap and abundant chiral amino acid derivative,was identified as the best chiral ligand to promote this atroposelective remote C-H functionalization reaction.

关键词： Palladiumcatalyst Axially chiral Acetylation Dibenzophosphorus oxide

Cloning of Na^+/H^+ antiport gene from Dunaliella salina

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Acta Geologica Sinica(English Edition) 2014年第S1期88卷 78-79页

作者： KONG Fanjing CHEN Susu MLR Key lab of saline lake and resources Institute of Mineral resources Chinese Academy of Geological Sciences

1 Introduction Dunaliella Salina,which taxi Dunaliella,Volvocales,Chlorophyceae Chlorophyta,is unicell algae with double flagllum at top,and cup shaped chloroplast without cell *** Salina is the most salt tolerance **... 详细信息

关键词： Dunaliella.Salina Na+/H+ antiport gene gene cloning degenerate primers RT-PCR.

Isolation and Identity of Halophiles in The Floating Bath Water in Yuncheng

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Acta Geologica Sinica(English Edition) 2014年第S1期88卷 341-342页

作者： KONG Fanjing WANG Xue HU Bin MLR Key lab of saline lake and resources Institute of Mineral resourcesChinese Academy of Geological Sciences

1 Introduction The study of floating bath began in 1914,by *** ***,the expert of medical and *** has done different kinds of floating experiments to study about the origin of consciousness and the relationship with **... 详细信息

关键词： Floating Bath Halophiles Halobacillus Virgibacillus

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Java动态类加载分析

计算机科学 2005年第4期32卷 194-196页

作者：左天军朱智林韩俊刚陈平西安电子科技大学软件工程研究所西安710071 西安邮电学院计算机系西安710061

动态类加载是Java的一个重要功能,它支持Java在运行时安装程序组件。Java的动态加载具有惰性加载、用户自定义加载策略以及动态名字空间等新特征。本文详细讨论了Java的动态加载机制,研究了动态加载与Java平台安全性之间的关系,分析了... 详细信息

动态类加载是Java的一个重要功能,它支持Java在运行时安装程序组件。Java的动态加载具有惰性加载、用户自定义加载策略以及动态名字空间等新特征。本文详细讨论了Java的动态加载机制,研究了动态加载与Java平台安全性之间的关系,分析了针对类加载的典型攻击,讨论了形式化验证的方法和存在的相应问题,最后总结全文并指出进一步研究的方向。

关键词：动态加载 Java平台用户自定义形式化验证安装程序名字空间安全性组件攻击