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Progress of Lyman-alpha-based beam emission spectroscopy(Ly BES)diagnostic on the HL-2. tokamak

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Plasma Science and Technology 2024年第3期26卷 118-125页

作者：周艺轩余羿许敏柯锐聂林徐皓赵光义刘灏袁子豪肖晨雨李继全肖池阶 the HL-2. Team Southwestern Institute of Physics Chengdu 610041People's Republic of China Sino-French Institute of Nuclear engineering and Technology Sun Yat-sen UniversityZhuhai 519082People's Republic of China State Key Laboratory of Nuclear Physics and Technology School of PhysicsPeking UniversityBeijing 100871People's Republic of China

An edge Lyman-alpha-based beam emission spectroscopy(LyBES)diagnostic,using a heating NBI(neutral beam injection)system,is currently under development on the HL-2. *** 2.-channel edge LyBES,which is intended to measure the density fluctuation in plasma edge(from R=1960 mm to R=2.2. mm)with an improved spatial resolution of 3.3 mm,is a complement to the existing conventional beam emission spectroscopy(BES)*** this article,we introduce the progress of LyBES diagnostic,including the collection optics,the monochromator,and the detector *** reflectance of the collection mirrors is measured to be~82.at 12. nm,and the aberration geometrical radius of the collection optics is tested to be~15.μm in the aimed *** linear dispersion of the LyBES monochromator is designed to be~0.09 nm mm^(-1).The bandwidth of the detector system with the 5.10^(7)V A^(-1)preamplifier gain is measured to be~2.0 kHz,and the peak-to-peak noise of the detector system is tested to be~16 *** finalized design,components development and testing of the LyBES diagnostic have been completed at present,and an overall performance of the LyBES diagnostic is to be confirmed in the next HL-2. campaign.

关键词： density fluctuation Ly BES BES vacuum ultraviolet

Direct gray-scale extraction of topographic features for vein recognition

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Science China(Information Sciences) 2010年第10期53卷 2062-2074页

作者： KANG WenXiong 1, LI HuaSong 2.& DENG FeiQi 1 1 College of Automation Science and engineering, South China university of Technology, Guangzhou {2.0640, China {2. of Information engineering, wuyi university,{{2., China 1. College of Automation Science and engineering South China University of Technology Guangzhou 510640 China2. School of Information Engineering Wuyi University Jiangmen 529000 China

Binarization processing is a key step in most vein pattern recognition, but may create flaws such as leakage of some feature information. In order to overcome this problem, a new approach is explored in this paper which can extract topographic features directly from gray-scale vein images without binarization processing. First, an extreme graph of directional fields (EGDF) is calculated according to neighborhood information of every pixel, and then the intravenous main ridge of the image can be separated step by step from EGDF with the defined constraint template sets. After that, the sub-ridge is extracted from end points of the main ridge in range constraint image with the tracing method of maximal neighboring point. According to contrast experiment the proposed method is better than the traditional processing (performing binarization first and then skeletonization), in that it can overcome the problem that some separate vein lines are extracted incorrectly, and it can avoid extracting two neighboring vein lines as one ridge. As such, the proposed method is an effective way to extract topographic features for vein recognition

关键词： vein recognition feature extraction directional fields

Effect of Preparation Methods on Mechanical Properties of PVA/HA Composite Hydrogel

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Journal of Bionic engineering 2010年第3期7卷 235-243页

作者： Dekun Zhang~1, Junjie Duan~1, Dagang Wang~2. Shirong Ge~2.1. school of Materials Science and engineering, China {2. of Mining and Technology Xuzhou 2.1116, P. R. China 2. school of Mechanical and Electrical engineering, China {2. of Mining and Technology, Xuzhou 2.1116, P. R. China [a] school of Materials Science engineering China University of Mining Technology Xuzhou 221116 P. R. China [b] School of Mechanical Electrical engineering China University of Mining Technology Xuzhou 221116 P. R. China

Poly(vinyl alcohol) (PVA)/hydroxyapatite (HA) composite hydrogel specimens were prepared with 15. PVA and 1%,2., 3%, 4% and 5. HA by repeated freezing-thawing. The tests of static and dynamic mechanical properties were carried out todiscuss the influence of different contents of HA and freezing-thawing cycles on the mechanical properties of PVA/HA compositehydrogel. The results of static mechanical tests showed that the PVA/HA composite hydrogel with 3% HA and ninefreezing-thawing cycles had excellent stress relaxation properties, higher relaxation ratio, lower stress equilibrium value andpresented better properties of creep and recovery. The results of dynamic mechanical test showed that the PVA/HA compositehydrogel with nine freezing-thawing cycles had higher storage modulus and loss modulus, so was the PVA/HA compositehydrogel with 3% HA.

关键词： composite hydrogel HA contents freezing-thawing cycles static properties dynamic properties

Analysis theory of random energy of train derailment in wind

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Science China(Physics,Mechanics & Astronomy) 2010年第4期53卷 751-757页

作者： CHEN RuiLin 1,2.3 , ZENG QingYuan 3 , HUANG YunQing 1 , XIANG Jun 3 , WEN Ying 3 , GUO XiaoGang 2., YIN ChangJun 2., DONG Hui 2.& ZHAO Gang 4 1 Hunan Key Laboratory for Computation and Simulation in Science and engineering, Xiangtan university, Xiangtan 41110{2. China {2. of Civil engineering & Mechanics, Xiangtan university, Xiangtan 41110{2. China 3 {{2. of Civil Architecture, Central South university, Changsha 41007{2. China 4 AMEC, Toronto M{2.{2.7, Canada 1. Hunan Key Laboratory for Computation and Simulation in Science and engineering Xiangtan University Xiangtan 411105 China2. School of Civil Engineering & Mechanics Xiangtan University Xiangtan 411105 China3. School of Civil Architecture Central South University Changsha 410075 China4. AMEC Toronto M5A5G7 Canada

Based on the analysis theory of random energy of train derailment, an analysis theory of random energy of train derailment in wind is suggested. Two methods are proposed -the time domain method and the frequency domain method of analysis theory of random energy of train derailment in wind. The curves of σ pw -v under various wind speeds are obtained through the computation. The original curve of σ p -v is expanded, which turns the analysis theory of random energy of train derailment into the all-weather theory. Train derailment condition has been established under wind action. The first and second criterions of train derailment have been proposed in light of wind action. The analysis of train derailment cases at home or abroad is made, in- cluding the first analysis of Xinjiang train derailment case encountered 13-level of gale, which explained the inevitability of train derailment. The analysis theory of random energy of train derailment in wind shows its validity and accuracy. The input energy σ pw of the transverse vibration of train-track(bridge)-wind system is linked to train speed. With the establishment of the analysis theory of random energy of train derailment in wind, It is likely to initiate an all-weather speed limit map for a train or any high-speed train.

关键词： train derailment analysis theory of random energy of train derailment analysis theory of random energy of train de- railment in wind train derailment condition in wind the criterion of train derailment in wind train derailment case

Optical pulse compression using a nonlinear optical loop mirror constructed from dispersion decreasing fiber

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Science China(Technological Sciences) 2004年第1期47卷 33-50页

作者： CAO Wenhua & LIU Songhaoschool of Information, wuyi university, {2. 5.902., China school for Information and Optoelectronic Science and engineering, South China Normal {5., Guangzhou 5.0631, China 1. school of Information Wuyi University 529020 Jiangmen China 2. school for Information and Optoelectronic Science and engineering South China Normal University 510631 Guangzhou China

A novel scheme to compress optical pulses is proposed and demonstrated numerically, which is based on a nonlinear optical loop mirror constructed from dispersion decreasing fiber (DDF). We show that, in contrast to the conventional soliton-effect pulse compression in which compressed pulses are always accompanied by pedestals and frequency chirps owning to nonlinear effects, the proposed scheme can completely suppress pulse pedestals and frequency chirps. Unlike the adiabatic compression technique in which DDF length must increase exponentially with input pulsewidth, the proposed scheme does not require adiabatic condition and therefore can be used to compress long pulses by using reasonable fiber lengths. For input pulses with peak powers higher than a threshold value, the compressed pulses can propagate like fundamental solitons. Furthermore, the scheme is fairly insensitive to small variations in the loop length and is more robust to higher-order nonlinear effects and initial frequency chirps than the adiabatic compression technique.

关键词： dispersion decreasing fiber (DDF), optical pulse compression, optical solitons.

Performance analysis of network coding for multicast relay system over Nakagami-m fading channels

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Science China(Information Sciences) 2011年第11期54卷 2338-2348页

作者： ZHAO Rui 1,YANG LvXi 2.& HUANG YongMing 2.1 school of Information Science and engineering,Huaqiao {2.,Xiamen 36102.,China 2.school of Information Science and engineering,Southeast {2.,Nanjing 2.0096,China 1. school of Information Science and engineering Huaqiao University Xiamen 361021 China2. School of Information Science and Engineering Southeast University Nanjing 210096 China

The outage probability performance of network coding for multicast relay system is analyzed in Nakagami-m fading *** transmission strategies,i.e.,complex field network coding (CFNC) and amplify-and-forward network coding (AFNC),are applied in the system,and the approximate expressions of outage probability are derived at high SNR and the conclusion is reached that the system diversity gains of two transmission strategies are both 2.,as is verified by numerical *** results also show that CFNC can outperform both AFNC and direct transmission without relay in the performances of system outage probability,sum rate and symbol error ratio.

关键词： multicast relay system network coding outage probability diversity gain

Dynamic Tensile Properties of Concrete under Different Environments

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Journal of Wuhan university of Technology(Materials Science) 2006年第4期21卷 163-168页

作者：闫东明 school of Civil and Hydraulic engineering Dalian University of Technology Dalian 116024 ChinaSchool of Environment and Water Conservancy Engineering Zhengzhou University Zhengzhou 450002China

By using an MTS810 hydra-electro-servo universal machine, the effect of moisture content and temperature on the rate sensitivity of concrete was irwestigated, the range of strain rate was varying from 10^- 5./ s to 10^-0.03/s. It is coneluded from the tests that the water content has a significant influence on the rate sensitivity of concrete whereas the tempature has a slight one, and the effects of rate sensitivity are attributed to both the viscosity caused by free water and the transformation of fracture mode when subjected to a high strain rate. The dynamic strength, initial modulus of elasticity, critical strain, Poisson ratio and energy absorption properties were studied systematically. It is found that the strength, initial modulus of elasticity, critical strain, and energy absorption capacity of concrete all increase with the increasing strain rate, whereas Poisson ratio keeps almost unchanged.

关键词： strain rate tension moisture content fracture mechanism

Ni60-SiC Coating Prepared by Plasma Spraying, Plasma Re-melting and Plasma Spray Welding on Surface of Hot Forging Die

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Journal of Wuhan university of Technology(Materials Science) 2011年第4期26卷 715-718页

作者：王洪福 school of Mechanical engineering and Automation North University of China

In order to produce the hear-resistant inner layer of hot-forging die, plasma spraying and plasma re-melting and plasma spray welding were adopted. Substrate material was W6Mo5.r4V2. including 10%, 2.%, 30% SiC ceramic powder used as coating material to obtain different Ni-based SiC alloys coating. Micro-structure and micro-hardness analysis of the coating layer were followed, as well as thermophysical properties for the coating layer were measured. The experimental results show that the coating prepared with 70% Ni60, 30% SiC powder has best properties with plasma spray welding, in which the micro-hardness can achieve 1100 HV, meanwhile can improve the thermal property of hot-forging die dramatically.

关键词： hot forging die plasma spraying plasma re-melting plasma spray welding thermo- physical properties

Influence of Ingredients of Carbon Black Nano-Particle Suspension of Ammonia Solution on Viscosity of Nanofluid

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湖南大学学报（自然科学版） 2009年第S1期36卷 115-118页

作者： CHENG Bo1,2.DU Kai1,ZHANG Xiao-song1,YANG Liu1(1.school of Energy & Environment,Southeast university,Nanjing,Jiangsu 2.0096,China {2. of Construction engineering,Anhui university of Technology,Maanshan,Anhui 2.3000,China) school of Energy and Environment Southeast University Nanjing 210096 China school of Construction engineering Anhui University of Technology Maanshan 243000 China

A series of experiments were performed on the viscosity of a nanofluid,produced by mixing carbon black and mulsifier OP-10 using ammonia-water with the ultrasonic *** results show that,when adding surfactant separately in low mass concentrations,at first the viscosity of solution decreases sharply compared with that of ammonia-water,then increases with increasing the concentration of *** a certain concentration of surfactant,the viscosity of nanofluids increases with increasing the concentration of *** on Einstein model and Langmuir absorption theory,a new model was summed up for *** with test values,the calculated values on the new model have verified that the model is suitable to predict the viscosity of nanofluids,because the maximum relative error is less than 5..Nano-particles absorption in the nanofluids is not only single-molecule layer adsorption,but also multi-layer molecular adsorption and other complicated *** the new model,only based on single-molecule layer adsorption theory of Langmuir,is not fully in line with the real circumstances.

关键词： nanofluid viscosity surfactant absorption