检索结果-南通市图书馆

Risk analysis model for landslide mass of high slope in dam area

在线全文

学校读者我要写书评

暂无评论

Science china(Technological Sciences) 2008年第S2期51卷 25-31页

作者： GU ChongShi1,2.HE XianFeng3,4,WU ZhongRu1,2.& SU HuaiZhi1,2.1 college of Water Conservancy and Hydropower engineering,Hohai University,Nanjing 2.0098,{2. 2.National engineering Research Center of Water Resources Efficient Utilization and engineering Safety,Nanjing 2.0098,{2. 3 Yellow River Institute of Hydraulic Research,zhengzhou 450003,{2. 4 Embankment Security Defect Prevention and Control engineering Research Center of MWR,zhengzhou 450003,{2. college of Water Conservancy and Hydropower engineering Hohai University Nanjing China National engineering Research Center of Water Resources Efficient Utilization and engineering Safety Nanjing China Yellow River Institute of Hydraulic Research Zhengzhou China Embankment Security Defect Prevention and Control engineering Research Center of MWR Zhengzhou China

In order to identify the threat of reservoir bank landslide to dam safety and reduce the risk of dam failure,impact factors of the landslide are *** concept of landslide risk degree is put forward to measure the threat of landslide to dam *** monotony of the landslide risk assessment function which changes with different affecting factors is analyzed *** on gene automatic programming,a data mining model of the landslide risk assessment function is constructed combined with impact factors of reservoir bank landslide on dam *** the assessment function of landslide risk has been excavated and established according to practical project information,which provides a valuable reference for analyzing the impact of landslide on dam risk.

关键词： landslide dam failure risk landslide risk

Perfect reconstruction image modulation based on BEMD and quaternionic analytic signals

在线全文

学校读者我要写书评

暂无评论

Science china(Information Sciences) 2011年第12期54卷 2622-2634页

作者： QIAO LiHong 1 , NIU KaiFu 2., WANG Ning 2.& PENG LiZhong 2.1 college of Information Science and engineering, Henan University of Technology, {2. 450001, china 2.School of Mathematical Sciences, Peking University, Beijing 100871, china college of Information Science and engineering Henan University of Technology Zhengzhou China School of Mathematical Sciences Peking University Beijing China

Image modulation represents image by meaningful characters such as image instantaneous amplitude and instantaneous frequency. A perfect reconstruction image modulation method is proposed. In detail, the bidimensional empirical mode decomposition (BEMD) is first improved to adaptively decompose image into monocomponents. Then by the quaternionic analytic method, suitable analytic signals is acquired. A new polar form is further proposed to modulate images, then seven characters are derived including instantaneous amplitude and instantaneous frequencies. We demonstrate the techniques on both synthetic and natural images, depict the needle program of the estimated frequencies and obtain the reconstructions that are the same with the original images. The applications in image segmentation and separation establish the validity of characterizing images of this type as sums of locally narrow band modulated components.

关键词： perfect reconstruction image modulation AM-FM representation BEMD quaternionic analytic signals

Gas Sensing Properties of ZnO Tetrapod-Like Whiskers Prepared by Hydrothermal Process

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

稀有金属材料与工程 2006年第S3期 185-187页

作者： Jiaqiang Xu~(1,2. Yuping Chen~1 Huanxin Wang~1 Jianian Shen~2.(1.college of Materials and Chemical engineering,{2. University of Light Industry,{2. 450002.china) (2.Institute of Materials,Shanghai University,Shanghai 2.0072.china)

ZnO tetrapod-like whiskers were prepared through a hydrothermal process using zinc powder as raw *** microstructure and morphology were characterized by X-ray diffraction （XRD） and transmission electron microscopy （TEM）. The XRD results showed that the crystal structure of as-obtained sample can be indexed to hexagonal wurtzite *** results revealed that the ZnO sample took on tetrapod-like whisker *** gas sensors were prepared with the traditional sintering process and their gas sensitivities were *** test results of gas sensitivity showed that the sensors based on ZnO tetrapod-like whiskers are very sensitive to dilute ethanol vapor and *** relatively high sensitivity and selectivity of these sensors made from ZnO tetrapod-like whiskers demonstrated the potential for developing a new class of selective ethanol sensors.

关键词： hydrothermal process gas sensor zinc oxide whisker

Gasoline Sensor Based on Flower-Like ZnO

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

稀有金属材料与工程 2006年第S3期 106-109页

作者： Xu Jiaqiang~(1,2. Chen Yuping~1 Li Chao~1 Shen Jianian~2.(1.college of Materials and Chemical engineering,{2. University of Light Industry,{2. 450002.china) (2.Institute of Materials,Shanghai University,Shanghai 2.0072.china)

Flower-like ZnO was prepared through a hydrothermal process using zinc sulfate as raw *** microstructure and morphology of the samples were characterized by X-ray diffraction （XRD） and transmission electron microscopy （TEM）.XRD results showed that the as-obtained sample could be indexed to hexagonal wurtzite *** results revealed that the ZnO sample presented flower-like *** gas sensors were prepared with the traditional sintering process and their gas sensitivities were *** gas sensitivity results showed that the sensors based on flower-like ZnO were very sensitive to dilute 90#*** relatively high sensitivity and selectivity of these sensors made from flower-like ZnO demonstrated the potential for developing a new class of selective gasoline sensors.

关键词： hydrothermal process gas sensor zinc oxide gasoline

Thermal Conductivity and Heat Transfer Coefficient of Concrete

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2011年第4期26卷 791-796页

作者：郭利霞 North china University of Water Resources and Electric Power

A very simple model for predicting thermal conductivity based on its definiensis was presented. The thermal conductivity obtained using the model provided a good coincidence to the investigations performed by other authors. The heat transfer coefficient was determined by inverse analysis using the temperature measurements. From experimental results, it is noted that heat transfer coefficient increases with the increase of wind velocity and relative humidity, a prediction equation on heat transfer coefficient about wind velocity and relative humidity is given.

关键词： thermal conductivity heat transfer coefficient relative humidity wind velocity

Creep Characteristics of Crumb Rubber Modified Asphalt Binder

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) 2011年第1期26卷 118-120页

作者：王岚 college of civil {2. Inner Mongolia University of Technology

Crumb rubber modified asphalt containing 2. percent crumb rubber particles of 30 mesh has been examined by Scanning Electron Microscope （SEM） to observe the microcosmic appearance and the characteristic distribution of crumb rubber particles in asphalt. The SEM pictures reveal that the crumb rubber particles distribute evenly in the asphalt and they are compatible well with asphalt. The shear creep test of crumb rubber modified asphalt was carried out at -10 ℃ and 40 ℃ by Dynamic Shear Rheology （DSR）. The shearing deformation at different temperature and creep stiffness modulus curve at loading stage of crumb rubber modified asphalt have been measured. The stiffness modulus of crumb rubber modified asphalt is much temperature sensitive and it decays much quick at the early stage of loading than normal asphalt. The rate of decay of stiffness modulus is slow at the subsequent stage and stiffness modulus approaches to a stable value at the final stage at a higher temperature. In addition, Burgers model is suitable to describe and simulate experimental results of viscoelastic properties of the crumb rubber modified asphalt.

关键词： crumb rubber modified asphalt creep stiffness modulus rheology model model parameter

Combination of drainage, water supply and environmental protection as well as rational distribution of water resource in zhengzhou mining district

在线全文

学校读者我要写书评

暂无评论

Science china Earth Sciences 2005年第10期48卷 1768-1779页

作者： WU Qiang1, LI Duo1,2. DI Zhiqiang3, MIAO Ying3, ZHAO Suqi4 & GUO Qiwen5 1. Resource Exploitation engineering college, CUMT, Beijing 100083, {2. 2. Shijiazhuang engineering college, University of Economics, Shijiazhuang 050031, {2. 3. Shenyang Institute of Geology and Mineral Resources, Shenyang 110032. {2. 4. State Adminstration of Coal Mine Safety, Beijing 100013, {2. 5. zhengzhou Coal Mine Company (Group), zhengzhou 452.71, {2. Resource Exploitation engineering college CUMT University of Economics Shenyang Institute of Geology and Mineral Resources State Adminstration of Coal Mine Safety zhengzhou Coal Mine Company (Group)

The geological condition of coalfield is much complex in china. With increasing in mining depth and drainage amount, the contradiction of drainage, water supply and environ-mental protection is becoming more and more serious. However, the contradiction can be solved by the scientific management of optimizing combination of drainage, water supply and environ-mental protection. The Philip multiple objectives simplex method used in this article has searched for a possible solution at the first step, and then it goes on searching to find out whether there is a weight number that can lead the solution to the biggest. It can reduce the randomness and diffi-culty of traditional weight method which determine the weight number artificially. Some beneficial coefficients are vague and the number is larger in the model of water resource dispatch. So the vague layer analysis method can consider these vague factors fully, combining the qualitative and quantitative analysis together. Especially, this method can quantify the experiential judge-ment of policy decider, and it will turn to be more suitable if the structure of objective factors is complex or the necessary data are absent. In the paper, the two methods above are used to solve the plans of drainage, water supply and optimizing distribution of water resource in the zhengzhou mining district.

关键词： combination of drainage, water supply and environmental protection, Philip multiple objective simplex method, vague layer analysis method, distribution of water resource.

Unified solutions for stresses and displacements around circular tunnels using the Unified Strength Theory

在线全文

学校读者我要写书评

暂无评论

Science china(Technological Sciences) 2010年第6期53卷 1694-1699页

作者： ZHANG ChangGuang1,WANG JiangFeng2.& ZHAO JunHai3 1 Department of Geotechnical engineering,Tongji University,Shanghai 2.0092.china 2.North china Institute of Water Conservancy and Hydroelectric Power,zhengzhou 450011,china 3 School of civil engineering,Chang’an University,Xi’an 710061,china Department of Geotechnical engineering Tongji University Shanghai China North china Institute of Water Conservancy and Hydroelectric Power Zhengzhou China School of civil engineering Chang’an University Xi’an China

The unified solutions are presented for stresses and displacements around a circular tunnel subjected to a hydrostatic stress *** rock mass is assumed to be elastic-brittle-plastic and governed by the Unified Strength *** displacements are obtained accounting for three different definitions for elastic strains and different Young's modulus in the plastic *** unified solutions obtained in this paper are especially versatile in reflecting the intermediate principal stress effect to different extents for different *** conventional solutions,based on the Mohr-Coulomb failure criterion and the Generalized Twin Shear Stress yield criterion,are special cases of the present unified *** new unified solutions can compare with those computed by the latest generalized Hoek-Brown failure *** results obtained demonstrate the importance of the intermediate principal stress influence for the stresses and displacements *** effects of different definitions for elastic strains and different Young's modulus in the plastic zone on the displacements are significant.

关键词： Unified Strength Theory intermediate principal stress different definitions for elastic strains different Young’s modulus

Hybrid particle swarm cooperative optimization algorithm and its application to MBC in alumina production

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2008年第11期18卷 1423-1428页

作者： Shengli Song~(a,b) Li Kong~a Yong Gan~b Rijian Su~(a,b) a Department of Control Scienee and engineering,Huazhong University oF Science and Technology,Wuhan 430074,china b {2. of Computer and Communication engineering,zhengzhou University of Light Industry,zhengzhou 450002.china Department of Control Science and engineering Huazhong University of Science and Technology Wuhan 430074 China college of Computer and Communication engineering Zhengzhou University of Light Industry Zhengzhou 450002 China

An effective hybrid particle swarm cooperative optimization(HPSCO)algorithm combining simulated annealing method and sim- plex method is *** main idea is to divide particle swarm into several sub-groups and achieve optimization through coop- erativeness of different sub-groups among the *** proposed algorithm is tested by benchmark functions and applied to material balance computation(MBC)in alumina *** show that HPSCO,with both a better stability and a steady convergence,has faster convergence speed and higher global convergence ability than the single method and the improved particle swarm optimization *** importantly,results demonstrate that HPSCO is more feasible and efficient than other algorithms in MBC.

关键词： PSO Simulated annealing Simplex Cooperative optimization