检索结果-南通市图书馆

Combining LBP and Adaboost for Facial Expression Recognition

在线全文

学校读者我要写书评

暂无评论

Combining LBP and Adaboost for Facial Expression Recognition

Study on the isothermal oxidation behavior in air of Ti_(3)AlC_(2. sintered by hot pressing

2.08 9th International Conference on Signal Processing(ICSP’2.08)

作者： Ying Zilu 1 2.Fang Xieyan 1 1.school of Information wuyi {2. jiangmen Guangdong 5.902. 2.school of Electronics and Information {5. Beihang {2. Beijing 100083

A novel approach to facial expression recognition based on the combination of local binary pattern（LBP） and Adaboost is ***,facial expression images are processed with LBP operator,which can eliminate the effect of environment lighting in a certain extent and has the powerful capability of texture feature *** then facial expression features are presented with LBP histograms of expression image which is divided into several *** features with powerful discriminability are selected by a modified Adaboost so as to predigest the design of classifier and shorten the cost ***,the support vector machine（SVM） classifier is used for expression *** algorithm is implemented with Matlab and experimented on Japanese female facial expression database（JAFFE database）.A facial expression recognition rate of 65.71% for person-independent is obtained and shows the effectiveness of the proposed algorithm.

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2006年第5期49卷 513-520页

作者： XU Xuewen1, 2. LI Yangxian1, MEI Bingchu2. ZHU Jiaoqun2. LIU Heyan1 & QU Jingping1 1. school of Material Science and engineering, Hebei {2. of Technology, Tianjin 300130, China 2. State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan Univer- sity of Technology, Wuhan 430070, China 1. school of Material Science and engineering Hebei University of Technology Tianjin 300130 China 2. State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan 430070 China

The isothermal oxidation behavior at 900–1300°C for 2. h in air of bulk Ti3AlC2.with 2.8 wt% TiC sintered by means of hot pressing was investigated in the work. The isothermal oxidation behavior generally followed a parabolic rate law. The parabolic rate constants increased from 1.39×10[10] kg[2.·m[4]·s[1] at 900°C to 5.5.×10[9] kg[2.·m[4]·s[1] at 1300°C. The calculated activation energy was 136.45.kJ/mol. It was demonstrated that Ti3AlC2.had excellent oxidation resistance due to the continuous, dense; adhesive protect scales consisted of a mass of α-Al2.3; a little of TiO2./or Al2.iO5. In principle, the oxide scale was grown by the inward diffusion of O[2.; the outward diffusion of Ti[4+]; Al[3+]. The rapid outward diffusion of cations usually resulted in the formation of cracks, gaps,; holes.

关键词： Ti3AlC2. oxidation behavior, kinetics.

Effect of Interfacial Bonding on the Toughening of Al_2._3/Ni Ceramic Matrix Composites

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 1996年第1期12卷 29-34页

作者： Xudong SUN(Dept. of Materials Science and engineering, Northeastern university, Shenyang 110006, China)J.A. Yeomans(Dept. of Materials Science and engineering, university of Surrey, Guildford, Surrey GU2.5.H, UK) Dept. of Materials Science and engineering Northeastern University Shenyang 110006 China Dept. of Materials Science and engineering University of Surrey Guildford Surrey GU2 5XH United Kingdom

The main Iimitation to the toughening of the α-Al2.3/Ni composite is the poor bonding atthe interface. which causes the nickel particles to be pulled-out during crack propagation with-out obvious plastic deformation. A proper control of oxygen content at the Al2.3-Ni interfacecan promote wetting at the intedece, and produce a mechanically interlocked and chemically strengthened intedece, causing most of the nickel particles to be stretched to failure and to expe-rience severe plastic deformation during crack propagation in the composite. Fracture toughnesstesting using a modified double cantilever beam method with in situ observation of crack prop-agation in a scanning electron microscope shows that the composite with the strengthenedinterface has a more desirable R-curve behaviour and a higher fracture toughness value than thenormal composite.

关键词： Al Effect of Interfacial Bonding on the Toughening of Al2.3/Ni Ceramic Matrix Composites Ni

Supporting of Nickel(Ⅱ) Acenaphthenediimine with Free Amino Group for Ethylene Polymerization

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan university of Technology(Materials Science) 2010年第2期25卷 260-264页

作者：胡扬剑 Department of Chemistry and Chemical engineering Huaihua College

Bis （4-（4-amino-3, 5.diethylbenzyl）-2. 6-diethylphenylimino） acenaphthene] di- chloronickel （NiLCl2. was prepared and supported on SiO2.modified by methyl trichlorsilane（S-1） and on SiO2.MgCl2.TiCl4 （S-2. respectively. Two supported catalysts S-1 and S-2.used as catalysts for ethylene polymerization were studied and the influences of various polymerization conditions, including the polymerization temperature, cocatalysts, Al/Ni molar ratio on the catalytic activity, branching degree and branch length of PE were also investigated. The experimental results show that the supported catalysts exhibit higher catalytic activity for ethylene polymerization, the highest catalytic activity of S-1 using AlEt2.l as cocatalyst at 5. ℃, reaching 5.8×10^5.PE/molNi·h, and needed lower Al/Ni molar ratio compared to homogeneous analogue.

关键词： nickel diimine complex supported catalyst branched polyethylene diethylaluminium chloride

A Study on Super Speed Forming of Metal Sheet by Laser Shock Waves

在线全文

学校读者我要写书评

暂无评论

厦门大学学报（自然科学版） 2002年第S1期41卷 127-128页

作者： ZHOU Jian-zhong 1, YANG Ji-chang 1, ZHANG Yong-kang 1, ZHOU Ming 2.(1. school of Mechanical engineering, Jiangsu {2., Zhenjiang, 2. 2.13 China 2. school of Material Science and engineering, Jiangsu {2., Zhenjiang 2. 2.00, China)

Metal sheet plastic deformation or forming is gener at ed through a mechanical pressure or a thermal variation. These pressure variatio ns or thermal variations can be created by a variety of means such as press form ing, hydroforming, imploding detonation and so on. According to the magnitude of the strain rates all these forming methods can be divided into quasi-static fo rming and dynamical forming. Up to now there are no reports of forming methods w ith the strain rates above 10 5.ec -1, even though the exploding forming. In this article, we work on a dynamic super-speed forming method driven by lase r shock waves and advanced a novel concept of laser shock forming. The initial o bservation of the laser shock forming is done through a bugle testing with speci mens of SUS430 sheet metal, using a neodymium-glass laser of pulse energy 10J～ 3 0J and duration of 2. ns (FWHM). The investigation revealed that the plastic de formation during the laser shock forming is characterized as ultrahigh strain ra te up to 10 7sec -1. We indicate that plastic deformation increases nonlin early when the energy density of the laser varies. By investigating the hardness and residual stress of the surfaces, we conclude that laser shock forming is a combination technique of laser shock strengthening and metal forming for introdu cing a strain harden and a compressive residual stress on the surface of the wor k-piece, and the treated surface by laser shock forming has good properties in fatigue and corrosion resistance. This technique can achieve forming wit h or without mould.

关键词： laser shock wave metal sheet forming ultrahigh strain rate residual stresses

Preparation and Characterization of Polylactide/Montmorillonite Nanocomposites

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan university of Technology(Materials Science) 2009年第4期24卷 562-565页

作者：吴选军 school of Chemical engineering Wuhan University of Technology

The montmorillonite, a form of layered silicate, was successfully intercalated into polylactide （PLA） matrix through solvent-casting technique. In addition, PLA/MMT nanocomposite films were produced, in which homogenous distribution of the silicate lamellae plays a key role in the mechanical properties of the films. A small amount（5.t%） of OMMT intercalated into the PLA matrix resulted in their flexibility enhancement, from 3.68%（pure PLA film） to 35..65.. The results of wide-angle X-ray diffraction （WAXD） patterns confirmed that the silicate interlayer distance increased from 3.044 nm （for OMMT） to 3.5.nm （for 5.t%, maximum） with increasing OMMT contents, but decreased to 3.319 nm when OMMT content was over 8wt%. FT-IR also verified the molecular-level associations between PLA chains and OMMT lamellae by vibration variances of hydrogen bonding. DSC thermograms demonstrated that thermal stabilities of the nanocomposite films enhanced, due to the silicate lamellae dispersed into PLA matrix.

关键词： polylactide montmorillonite nanocomposite characterization thermo-mechanic at property

Study on Ceramic Cutting by Plasma Arc

在线全文

学校读者我要写书评

暂无评论

厦门大学学报（自然科学版） 2002年第S1期41卷 55-56页

作者： XU Wen-ji 1, FANG Jian-cheng 2. LU Yi-shen 1 (1. school of Mechanical engineering, Dalian {2. of Technology, Dalian 11602., China 2. College of Mechanical engineering and Automation, Huaqiao {2., Quanzhou 362.11, China)

engineering ceramics are typical difficult-to-machine materials because of high hardness and brittleness. PAC (Plasma Arc Cutting) is a very important thermal cutting process and has been successfully used in cutting stainless steel and other difficult-to-machine alloys. PAC’s application in cutting ceramics, however, is still limited because the most ceramics are not good electronic conducts, and transferred plasma arc cannot be produced between cathode and work-piece. So we presented a method of plasma arc cutting engineering ceramics with additional anode. To reduce the kerf width and to improve the kerf quality, the hydro-magnetically confined plasma arc is used to cut engineering ceramic plates. By experiments and analyses the mechanism and characteristics of hydro-magnetic confined plasma are discussed and the effects of secondary confinement on cutting quality, arc properties, and optimal process parameters are presented. When the nozzle diameter is 3 mm, the kerf width of the Al 2. 3 ceramic plate with 6 mm thickness is less than 4.6 mm, and the cutting speed reaches to 0.9～1.2.m/min. Both theoretical analysis and experimental results have proved the feasibility and validity of the newly advanced hydro-magnetic plasma arc cutting, and the following conclusion can be drawn: (1)Synthesizing the advantages of both the water-constriction and magnetic constriction, the hydro-magnetic constriction of plasma arc forms a three-dimensional constriction with improved shape and uniformity of arc column, narrower kerfs, minimal beveling of cuts and higher dross-free cutting speeds than those under either water-constriction or magnetic constriction alone.(2.Hydro-magnetic constriction is capable of improving arc stability, which is reflected in the higher arc voltage at which arc-extinction occurs, than that under any single constriction. (3)For a given diameter of nozzle, quality cut can be produced by using a lower arc current than usually required in conventional plas

关键词： plasma cutting engineering ceramic plasma confinement

Minocycline inhibits 5.lipoxygenase activation and brain inflammation after focal cerebral ischemia in rats

在线全文

学校读者我要写书评

暂无评论

Acta Pharmacologica Sinica 2007年第6期28卷 763-772页

作者： Li-sheng CHU~(2.3),San-hua FANG~2.Yu ZHOU~2.Guo-liang YU~2.Meng-ling WANG~2.Wei-ping ZHANG~2.Er-qing WEI~(2.4)~2.Department of Pharmacology,school of Medicine,Zhejiang university,Hangzhou 3100{2.,China ~3 Department of Physiology ZhejiangChinese Medical university Hangzhou 3100{2.,China Department of Pharmacology School of Medicine Zhejiang University Hangzhou 310058 China

Aim:To determine whether the anti-inflammatory effect of minocycline on postis-chemic brain injury is mediated by the inhibition of 5.lipoxygenase （5.LOX）expression and enzymatic activation in ***:Focal cerebral ischemiawas induced for 30 min with middle cerebral artery occlusion,followed *** ischemic injuries,endogenous IgG exudation,the accumulationof neutrophils and macrophage/microglia,and 5.LOX mRNA expression weredetermined 72.h after reperfusion.5.LOX metabolites （leukotriene B4and cysteinylleukotrienes） were measured 3 h after ***:Minocycline （2..5.nd 45.mg/kg,ip,for 3 d） attenuated ischemic injuries,IgG exudation,and theaccumulation of neutrophils and macrophage/microglia 72.h after *** inhibited 5.LOX expression 72.h after reperfusion and the production ofleukotrienes 3 h after reperfusion,Conclusion:Minocycline inhibited postis-chemic brain inflammation,which might be partly mediated by the inhibition of5.LOX expression and enzymatic activation.

关键词： minocycline 5.1ipoxygenase leukotriene focal cerebral ischemia inflammation

Characterzation and separation of Al_(13) species using gel-filtration chromatography

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2006年第4期49卷 326-331页

作者： CHU Yongbao1,2. GAO Baoyu1, YUE Qinyan1, WANG Yan1 & WANG Shuguang1 1. school of Environmental Science and engineering, Shandong {2., Jinan 2.3}100, China 2. College of Material and Environment, Qingdao {2. of Science and Technology, Qingdao 2.6042. China school of Environmental Science and engineering Shandong University Jinan China College of Material and Environment Qingdao University of Science and Technology Qingdao China

A polyaluminum chloride (PAC) sample was prepared using a slow alkalinetitration method. The Bio-Gel P-100 gel column chromatographic technique was used to separate andcharacterize the various forms of aluminum present in the prepared PAC solution. The effluents froma gel column were monitored using online chemical method: AI-Ferron timed complexationspectropho-tometry and by ^(2.)Al nuclear magnetic resonance (NMR) spectroscopy. Effects ofdifferent experimental conditions such as eluent flow rate, ionic strength and pH on separation ofAl_(13) were investigated. Experimental results indicated that molecule size exclusion was not theonly parameter affecting the column chromatographic separation efficiency of Al_(13) but moleculecharge as well. Reducing the eluent flow rate, increasing the ionic strength and suitable pHresulted in increase in the separation efficiency. Experimental results clearly indicated that byvarying the experimental conditions, it is possible to produce pure Al_(13) species using a gelcolumn chromatographic technique.

关键词： Al13 species, column chromatography, polyaluminum chloride (PAC), separation and purification.