检索结果-南通市图书馆

Study on flow behavior and structure over chined fuselage at high angle of attack

在线全文

学校读者我要写书评

暂无评论

Science china(Technological Sciences) 2010年第8期53卷 2057-2067页

作者： TIAN Wei,DENG XueYing ,WANG YanKui,FAN GuoLei&DONG Chao ministry of education {2. laboratory of Fluid Mechanics,Beijing university of Aeronautics and Astronautics,Beijing 100191,china 1. ministry of education {2. laboratory of Fluid Mechanics Beijing University of Aeronautics and Astronautics Beijing 100191 China

A study of leeward vortex structure over chined fuselage and the effects of micro tip perturbation on its vortex flow have been carried out in wind tunnel experiments at Reynolds numbers from 1.2.×105 to 5.04×105 with PIV and pressure measurement ***,the experiment results have proved that micro tip perturbation has no effects on the vortex flow and its aerodynamic characteristics over chined fuselage at high angle of attack,in which there are not any non-deterministic flow ***,the evolution of leeward vortex structure over chined fuselage along the axis of model can be divided into four flow regimes:linear conical developed regime,decay regime of leeward vortex intensity,asymmetric leeward vortex break down regime and completely break down *** a correlation between leeward vortex structure and sectional aerodynamic force was also revealed in the present ***,the experiment results show the behavior of leeward vortex core trajectories and zonal characteristics of leeward vortex structure with angles of ***,the experiment results of Reynolds number effect on the leeward vortex flow have further confirmed research conclusions from previous studies:the flows over chined fuselage at high angles of attack are insensitive to variation of Reynolds number,and there is a little effect on the secondary boundary layer separation and the suction peak induced by leeward vortex.

关键词： high angle of attack aerodynamics chined fuselage tip perturbation leeward vortex structure zonal characteristics

MONTE-CARLO SIMULATION FOR ATOMIC DEPOSITION OF AMORPHOUS ELECTROLESS Ni_(80)P_(2.) COATING

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2002年第5期15卷 479-486页

作者： K.S. Guan, H.R. Bai, Z.W. Wang and Y.S.YinResearch Institute of Process Equipment, East china university of Science and Technology, Shanghai 2.02.7, chinaLaiyang Agricultural College, Shandong 2.52.0, chinakey Lab. for liquid structure and heredity of ministry of education, Engineering Ceramics key Lab. of Shandong Province, Ji’nan 2.0061. china Research Institute of Process Equipment East China University of Science and Technology Laiyang Agricultural College

Atomic growth process and structure of Amorphous Electroless Coating have been studied, using Monte-Carlo simulation method. The simulation results of amorphous Ni80P2. coating show that PDFs are in accordance with practical values. The migrations of adatoms in coating's growth are different from that of solidification of amorphous materials. In some cases, the migrated adatoms in the process of growth of amorphous coating are not enough to occupy all vacancies and traps, so the amorphous coating is micro-porous. The immovable probability k and the largest migration distance of adatoms, which lie on the electroless bath components, affect the PDF, volume density and microporosity remarkably.

关键词： electroless Ni-P alloy computer simulation Monte-Carlo method amorphous material

Effect of Organophilic Montmorillonite on Thermal-oxidative Aging Behavior of SBS Modified Bitumen Crack Filling Material

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 673-676页

作者：余剑英 key laboratory of Silicate {2. Science and Engineering of education ministry Wuhan University of Technology

Styrene-butadiene-styrene （SBS） modified bitumen crack filling material with organophilic montmorillonite （OCFM） was prepared by melt blending. X-ray diffraction analysis shows that the interlayer spacing of organophilic montmorillonite （OMMT） in OCFM is widened and an exfoliated structure may be formed. Thermal-oxidative aging behavior of OCFM and SBS modified bitumen crack filling material （SCFM） was investigated. The experimental results indicate that the rate of thermal-oxidative aging of OCFM is much slower than that of SCFM, which can be attributed to barrier of exfoliated structure of OCFM to oxygen.

关键词： organophilic montmorillonite SBS modified bitumen crack filling material thermal-oxidative aging

Surface Motion of Alluvial Valley in Layered Half-Space for Incident Plane P-Waves

在线全文

学校读者我要写书评

暂无评论

Transactions of Tianjin university 2011年第3期17卷 157-165页

作者：巴振宁梁建文 School of Civil Engineering Tianjin University key laboratory of Coast Civil {2. Safety of ministry of education

The indirect boundary element method (IBEM) is used to study the surface motion of an alluvial valley in layered half-space for incident plane P-waves based on Wolf’s theory. Firstly, the free field response can be solved by the direct stiffness method, and the scattering wave response is calculated by Green’s functions of distributed loads acting on inclined lines in a layered half-space. The method is verified by comparing its results with literature and numerical analyses are performed by taking the amplification of incident plane P-waves by an alluvial valley in one soil layer resting on bedrock as an example. The results show that there exist distinct differences between the wave amplification by an alluvial valley embedded in layered half-space and that in homogeneous half-space and there is interaction between the valley and the soil layer. The amplitudes are relatively large when incident frequencies are close to the soil layer’s resonant frequencies.

关键词： layered half-space alluvial valley plane P-waves scattering one layer over bedrock indirect boundaryelement method

Floating Population Increase and Its Influence on the Urban Population Situation:A Case Study in Beijing

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Population,Resources and Environment 2005年第1期3卷 27-35页

作者： Wu Peilin 1,2.& Lu Qi 2.1. Shandong university of Technology, Zibo Shandong 2.5049, china 2. Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, china Shandong university of Technology Zibo Shandong 255049 China Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China

Floating population is a special population group in china resulting from the implementation of household registration system. This paper uses a set of floating population survey data, population censuses data and statistical data to analyze the increase and influence of floating population on the urban population situations in Beijing. It is found that Beijing has experienced a rapid increase of floating population since the 1990s and that the increase of this group has become the key factor of the current population expansion in the city. Its distribution in the urban regions intensified and extended the suburbanization process of the capital. In addition, the population {2.s of sex, age, education and employment in Beijing have changed to some extent due to the influx of floating population.

关键词： Floating population Household registration system (Hukou) Population expansion Suburbanization Population structure Beijing

The Coordination State of B and Al of Borosilicate Glass by IR Spectra

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) 2008年第3期23卷 419-421页

作者：万军鹏 key laboratory of Silicate {2. Science and Engineering Wuhan University of Technology Ministry of Education

The IR spectra of R2.-RO-B2.3-SiO2.and R2.-RO-B2.3-Al2.3-SiO2.glasses were tested for the study of coordination state of B, Al and their content. The results show that no matter Na2./B2.3〉1, =1, or〈1, both [BO3] and destroyed Si-O bond exist in glass structure; the addition of Al2.3 to borosilicate glass reduced both the number of non-bridging oxygen in the silicate network and the number of [BO4] units.

关键词： borosilicate glass IR spectra coordination structure

EXPERIMENTAL MEASUREMENT OF MAGNETIC FIELD IN A NOVEL FLOW CONTROL OF MOLD

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2002年第3期15卷 260-266页

作者： G.J. Xu, D.H. Li and J.C. HeThe key laboratory of National {2. ministry for Electromagnetic Processing of materials, Northeastern university, Shenyang 110006, china Manuscript received 10 September 2.01 The key laboratory of National {2. ministry for Electromagnetic Processing of materials North-eastern University Shenyang 110006 China

In order to know the distribution of magnetic field in a novel flow control of mold (NFC Mold) and to provide the experimental data for the electromagnetic structure design and the analysis of flow control in continuous casting mold, the magnetic field in a NFC Mold were measured by Tesla meter of Model CT-3. The method of vector synthesis was adopted in the measurement of magnetic fields. The results showed that the magnetic field in the NFC Mold was composed of two main magnetic areas that were symmetrical. Although there was leaking magnetic flux between the lower surface of the upper pole and the upper surface of the lower pole on the sides, it was restrained by the main magnetic fields effectively. Therefore the NFC Mold was more preferably satisfied to be used in controlling the molten steel flow in continuous casting mold.

关键词： continuous casting,mold,measurement of magnetic field method of vector synthesis

Preparation of graphene and TiO2.layer by layer composite with highly photocatalytic efficiency

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:materials International 2011年第6期21卷 467-471页

作者： Yu-peng ZHANG~1,Jun-jie XU~1,Zhi-hua SUN~1,Chen-zhe LI~1,Chun-xu PAN~(1,2. 1.key laboratory of Artificial Micro- and Nano-{2.s of ministry of education, School of Physics and Technology,Wuhan university,Wuhan 430072.china 2.Center for Electron Microscopy,Wuhan university,Wuhan 430072.china [a] key laboratory of Artificial Micro- and Nano-{2.s of ministry of education School of Physics and Technology Wuhan University Wuhan 430072 China [b] Center for Electron Microscopy Wuhan University Wuhan 430072 China

A process for fabricating graphene and TiO2.ayer by layer composite was introduced to improve the photocatalytic activity by controlling the layers,thickness and the mass ratio between graphene and *** graphene oxide（GO） was synthesized from natural graphite powder by the modified Hummers ***-area uniform GO and TiO2.hin films were made by a spin-coating process in *** exposure of the TiO2.GO multilayer film to UV light irradiation which allows the reduction of GO to graphene,a novel photocatalytic structure as graphene and TiO2.ayer by layer composite was *** cross-sectional SEM image showed that a clear layer by layer microstructure with a single layer thickness of graphene or TiO2.as in the range of about 50 *** total thickness of the film was around 5μm which was varied according to the layer number of spin coating *** spectra revealed that significant structural changes occurred through UV light *** for methylene blue（MB） exhibited that the layer by layer composite is of higher photocatalytic activity than the pure TiO2.ayer.

关键词： graphene TiO2 photocatalysis layer by layer composite

Primary structure and configuration of tea polysaccharide

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(Life Sciences) 2004年第5期47卷 416-424页

作者： ZHOU Peng1, XIE Mingyong1, NIE Shaoping1 & WANG Xiaoru2.1. key laboratory of Food Science of {2. of education, Nanchang university, Nanchang 330047, china 2. key laboratory of Analytical Science of {2. of education, Xiamen university, Xiamen 361005, china 1. key laboratory of Food Science of {2. of education Nanchang University 330047 Nanchang China 2. key laboratory of Analytical Science of {2. of education Xiamen University 361005 Xiamen China

The monosaccharide composition of a tea polysaccharide (TGC) was determined by GC-MS method. Furthermore, the primary structure of tea polysaccharide and its configura-tion in the aqueous solution were investigated utilizing a combination of classical chemical methods and modern instrumental techniques including GC-MS, Proton NMR, UV and CD. The results indicate that TGC consists of 6 monosaccharides: Rha, Ara, Xyl, Glu, Man and Gal. The configuration of TGC in water solution is proposed to be an ordered helix. The possible primary structure of TGC was outlined as below: the basic structure of the main chain consists of Rha, Glu and Gal units. All three monosaccharides can potentially be connected to branch chains consisting of mainly Ara, and the linkages could be in b1→2. b 1→3, b 2.3 forms. When branch chain is absent in the basic structure of the main chain the linkage consists of only b 1→3; Xyl exists at the terminal end of either the main chain or the branch chain with b 1→ linkage.

关键词： GC-MS,NMR,tea polysaccharide,primary structure,configuration.