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SLIP SYSTEMS AND DISLOCATION DISTRIBUTION IN α-PHASE OF SUPERPLASTICALLY DEFORMED Ti-6AI-4V ALLOY

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Acta Metallurgica Sinica(English Letters) 1990年第4期3卷 256-261页

作者： ZHAO Linruo ZHANG Shaoqing YAN Minggao Institute of Aeronautical Materials,Beijing,china lab.No.4,Beijing Institute of Aeronautical Materials,Beijing 100095,china

The activated slip systems in the α-phase of the superplastically deformed Ti-6Al-4V alloy were analyzed by systematic operation method with *** results show that the dominately activated slip systems in the α-phase are{01(?)0}〈2(?)0〉and{01(?)}2(?)0〉, The{0001}〈2(?)0〉system as well as the c+a dislocalions of b=[1/3]〈11(?)3〉will be acti- vated when the deformation temperature is *** amounts of TEM observations in- dicate that the dislocations in the α-phase were mainly activated near the triple grain bounda- ry junctions,α/α grain boundaries and α/β interlaces.

关键词： titanium alloy superplastic deformation dislocation

A novel adaptive spectrum forming filter:Application in cognitive ultra-wideband

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Science china(Information Sciences) 2010年第12期53卷 2584-2599页

作者： LI Bin ,ZHOU Zheng & ZOU WeiXia Key lab of Universal Wireless Communications,MOE.Wireless Network lab,Beijing University of Posts and Telecommunications,Beijing 100876,china Key lab of Universal Wireless Communications MOE. Wireless Network Lab Beijing University of Posts and Telecommunications Beijing China

Ultra wideband impulse radio(UWB-IR) has important applications in high data rate communications,high precision positioning and penetrating target *** with cognitive radio(CR),UWB can also greatly alleviate the current spectrum ***,the existing UWB waveforms are faced with two *** spectrum utilization of UWB signal is rather low,which reduces the communication ***,it appears difficult for UWB-IR to avoid spectrum collision with other incumbent *** UWB will inevitably interfere other legal wireless *** by these considerations,we model the UWB waveform design into an interpolation *** on radial basis function neural network,a novel UWB pulse is presented in this *** UWB pulse is then realized though reasonable simplification on the already proposed theoretical *** designed UWB pulses can adaptively track the external spectral environment where UWB devices work and reconfigure its emission spectrum according to the state of primer users without any modification on *** frequency utilization is maximized when there is no active primary *** adequate spectrum avoidance has also been achieved without much spectrum utilization degradation within the non-primary *** and analysis show that our UWB-IR pulse is much superior to the other existing UWB signals in the frequency utilization,spectrum avoidance and in the transmission performance.

关键词： UWB-IR cognitive radio pulse design RBF network spectrum efficiency spectrum avoidance

One-pot synthesis of hyperbranched poly(amido amine) clicked with a sugar shell via Michael addition polymerization and thiol click reaction

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Science china Chemistry 2010年第8期53卷 1663-1668页

作者： YU ZhiQiang,CUI MengMeng,YAN JunJie & YOU YeZi CAS Key lab of Soft Matter Chemistry Department of Polymer Science and Engineering,University of Science and Technology of china,Hefei 230026,china CAS Key lab of Soft Matter Chemistry Department of Polymer Science and Engineering University of Science and Technology of China Hefei China

This paper reports the production of glycopolymers via a simple and flexible method.A novel glycopolymer with a hyperbranched poly(amido amine) core and a sugar shell (HPAA-GLc) was synthesized by using thiol-ene click reaction via facile one-pot *** poly(amido amine) with vinyl terminals was first synthesized by Michael addition polymerization of N,N'-methylene bisacrylamide (MBA) with 1-(2-aminoethyl) piperazine (AEPZ).Subsequently,thiol-ene click reaction between vinyl units of hyperbranched poly(amido amine) and thio-glucose was performed in *** on the NMR result,all the vinyl groups reacted with thiol-glucose in 120 *** photoluminescence emission was observed from the aqueous solution of HPAA-GLc.

关键词： thiol-ene click reaction glycopolymers hyperbranched poly(amido amine) photoluminescence

In situ preparation of Nanoparticles/polymer composites

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Science china(Technological Sciences) 2008年第11期51卷 1886-1901页

作者： SUN HaiZhu & YANG Bai State Key lab of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, china College of Chemistry, Northeast Normal University, Changchun 130024, china State Key lab of Supramolecular Structure and Materials College of Chemistry Jilin University College of Chemistry Northeast Normal Universit

Nanoparticle (NP) is the matter between molecule and bulk material. It has attracted much attention in catalysis, optoelectronics and biology due to its unique physical and chemical properties. Incorporation of these NPs into the polymer matrix is one of the best methods to display their special functions, which not only stabilize the NPs but also realize the functional assembly of NPs and polymers. However, reali- zation of this idea depends largely on the compatibility of NPs and polymers as well as the interaction between them. Therefore, many methods have been developed to prepare the composites of NPs and polymers in order to obtain the function ex- pected. In this review, we mainly focus on the combination of in situ method with other methods to synthesize different functional one-dimension, two-dimension as well as bulk composites, which has been recently developed by our group. The most striking character of our method is the excellent compatibility between NPs and polymers which ensures a homogeneous distribution of NPs in the polymer matrix. The existence of the polymer network makes the NPs more stable, and is significant for displaying their functions.

关键词： in situ nanoparticle polymer composite function

Microstructure of Differently Annealed NanocrystallineFe_(72.7)Cu_1Nb_(1.8)Mo_2Si_(13)B_(9.5) Alloy

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Journal of Materials Science & Technology 1998年第4期14卷 327-330页

作者： YanZhong ZHANG and Huijuan JIN (Shanghai Key lab. of Metallic Functional Materials, Shanghai Iron and Steel Research Institute,Shanghai 200940, china) Shanghai Key lab. of Metallic Functional Materials Shanghai Iron and Steel Research Institute Shanghai 200940 China

The microstructure of differently annealed nanocrystalline Fe72.7Cu1Nb1.8Mo2Si13B9.5 alloy was investigated by using Mssbauer spectroscopy and transmission electron microscope. The specimens were isochronally annealed at temperatures between 480℃ and 600℃ for 0.5 h. The experimental results show that the microstructure mainly consists of the nanoscale bcc α-Fe(Si) grains and the residual amorphous matrix phase. A trace paramagnetic phase was found for annealing about above 500℃. The volume fraction of cr-Fe(Si) grain increases with increasing annealing temperature, whereas the average size of grain is almost unchanged above 480℃ up to 580℃. The calculated thickness of the intergranular layer of the residual amorphous matrix clearly decreases with increasing annealing temperature.

关键词： Mo2Si Microstructure of Differently Annealed NanocrystallineFe Si Alloy Cu1Nb

Thermodynamic Calculation of A_(r3) Temperature inLow Alloy Steels

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Journal of Materials Science & Technology 1998年第4期14卷 380-382页

作者： Jinbo QU Zhenyu LIU Xianghua LIU and Guodong WANG (State Key lab. of Rolling and Automation, Northeatern University Shenyang 110006, china) State Key lab. of Rolling and Automation Northeastern University Shenyang 110006 China

On the basis of superelement model, Cahn's transformation kinetics theory and Scheil's additivity rule, actual γ/α transformation start temperature, A.3 in Fe-Σ Xi-C (Xi=Mn, Si, Ni, Mo etc.)multi-component low alloy Steels during continuous cooling process was calculated. Influences of chemical composition, hot deformation of γ and cooling rate on Ar3 temperature were analyzed. Calculated Ar3 temperatures are in reasonable agreement with measured ones.

关键词： Si Temperature inLow Alloy Steels Thermodynamic Calculation of A r3

Investigation on the Tribology of Co Implanted Stainless Steel Using Metal Vapor Vacuum Arc Ion Source

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Journal of Materials Science & Technology 2004年第3期20卷 265-268页

作者： Junxia GUO Xun CAI Qiulong CHEN Key lab for High Temperature Materials and Testing, Shanghai Jiao Tong University, Shanghai 200030, china lab. for High Temp. Mat. and Testing Shanghai Jiaotong Univ. Shanghai 200030 China

AISI 304 stainless steel was ion implanted with Co, and the tribological property on the surface of the stainless steelwas investigated. The Co ion implantation was carried out using a metal vapor vacuum arc (Mevva) broad-beam ionsource with an extraction voltage of 40 kV, implantation doses of 3×10^(17)/cm^2 and 5×10^(17)/cm^2, and ion currentdensities of 13, 22 and 32μA/cm^2. The results showed that the near-surface hardness of Co-implanted stainless steelsample was increased by 50% or more, and it increased with increasing ion current density at first and then declined.The friction coefficient decreased from 0.74 to 0.20 after Co implantation. The wear rate after Co implantationreduced by 25% or more as compared to the unimplanted sample. The wear rate initially decreased with increasingion current density and then an increase was observed. Within the range of experimental parameters, there existsa critical ion current density for the Co-implanted stainless steel, at which the wear rate decreased with increasingretained dose, going through a minimum and then increased. The critical ion current density in this paper is about22μA/cm^2.

关键词： Tribology Metal vapor vacuum arc Cobalt Implanted stainless steel

Synthesis and Properties of Laβ-Al_2O_3

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Journal of Materials Science & Technology 1997年第2期13卷 157-160页

作者： Congjin JIN Yanruo HONG (State Support lab. on Solid Electrolytes and Testing Techniques, University of Science & Technology Beijing,Beijing 100083, china) State Support lab. on Solid Electrolytes and Testing Techniques University of Science and Technology Beijing Beijing 100083 China

Laβ-Al2O3 solid electrolytes were synthesized directly and their conductivities were measured in terms of ac impedance *** magnitude of conductivities is 10-6 to 10-2 S·*** on these data, the dependence of the conductivity of Laβ-Al2O3 upon the temperature and the dopant concentration in the electrolytes was studied, and the activation energy for conduction was calculated, which is 0.89 eV to 1.02 eV from 450℃ to 1000℃. The ion transference numbers were also determined.

关键词： Al2O3 Synthesis and Properties of La

Improvement and Realization of DSR Routing Protocol with QoS Support in Wireless Mesh Networks

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china Communications 2009年第1期6卷 123-127页

作者： Gu Xiaoyan , Liu Feng Image Processing and Image Communications Key lab, Nanjing University of Posts and Telecommunications, Nanjing 210003, china Image Processing and Image Communications Key lab Nanjing University of Posts and Telecommunications Nanjing 210003 China

In Wireless Mesh Network,multimedia applications require the network to guarantee Quality-of-Service(QoS). A new QoS-aware routing protocol based on DSR named QDSR(QoS-DSR) is further proposed. QDSR guarantees the QoS of application, such as bandwidth and delay, defines routing cost function according to the number of hops of path and buffer and chooses the best path based on routing cost. Simulation results show that, compared with DSR, QDSR greatly improves the throughput, reduces the average end to end delay, improves the efficiency, satisfies the QoS of application better and has stronger applicability and expansibility.

关键词： Wireless Mesh network Quality-of-Service routing protocol bandwidth delay routing cost function