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排序方式: 共有1043条查询结果,搜索用时 31 毫秒
31.
对应用模糊推理进行系统预测进行了深入的研究,建立了以震级和震源深度为输入的基于Mamdani型模糊推理的震中烈度预测模型.并以四川地区震例数据为例,对数据信息提取,模糊规则建立等关键环节进行了详细的介绍,预测结果分析表明推理模型是可行和有效的. 相似文献
32.
Hilmi Demiray 《Applied mathematics and computation》2011,218(5):2294-2299
In the present work, utilizing the two dimensional equations of an incompressible inviscid fluid and the reductive perturbation method we studied the propagation of weakly nonlinear waves in water of variable depth. For the case of slowly varying depth, the evolution equation is obtained as the variable coefficient Korteweg-de Vries (KdV) equation. Due to the difficulties for the analytical solutions, a numerical technics so called “the method of integrating factor” is used and the evolution equation is solved under a given initial condition and the bottom topography. It is observed the parameters of bottom topography causes to the changes in wave amplitude, wave profile and the wave speed. 相似文献
33.
Z.H. Zhang X.L. Zhong H. Liao F. Wang J.B. Wang Y.C. Zhou 《Applied Surface Science》2011,257(17):7461-7465
In the present work, X-ray photoelectron spectroscopy (XPS) was used to investigate the composition depth profiles of Bi3.15Nd0.85Ti3O12 (BNT) ferroelectric thin film, which was prepared on Pt(1 1 1)/Ti/SiO2/Si(1 0 0) substrates by chemical solution deposition (CSD). It is shown that there are three distinct regions formed in BNT film, which are surface layer, bulk film and interface layer. The surface of film is found to consist of one outermost Bi-rich region. High resolution spectra of the O 1s peak in the surface can be decomposed into two components of metallic oxide oxygen and surface adsorbed oxygen. The distribution of component elements is nearly uniform within the bulk film. In the bulk film, high resolution XPS spectra of O 1s, Bi 4f, Nd 3d, Ti 2p are in agreement with the element chemical states of the BNT system. The interfacial layer is formed through the interdiffusion between the BNT film and Pt electrode. In addition, the Ar+-ion sputtering changes lots of Bi3+ ions into Bi0 due to weak Bi-O bond and high etching energy. 相似文献
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36.
T. Terlier R. Tiron A. Gharbi X. Chevalier M. Veillerot E. Martinez J.‐P. Barnes 《Surface and interface analysis : SIA》2014,46(2):83-91
Directed self‐assembly of block copolymers (BCPs) is a promising candidate for next generation nanolithography. In order to validate a given pattern, the lateral and in‐depth distributions of the blocks should be well characterized; for the latter, time‐of‐flight (ToF) SIMS is a particularly well‐adapted technique. Here, we use an ION‐TOF ToF‐SIMS V in negative mode to provide qualitative information on the in‐depth organization of polystyrene‐b‐polymethylmethacrylate (PS‐b‐PMMA) BCP thin films. Using low‐energy Cs+ sputtering and Bi3+ as the analysis ions, PS and PMMA homopolymer films are first analyzed in order to identify the characteristic secondary ions for each block. PS‐b‐PMMA BCPs are then characterized showing that self‐assembled nanodomains are clearly observed after annealing. We also demonstrate that the ToF‐SIMS technique is able to distinguish between the different morphologies of BCP investigated in this work (lamellae, spheres or cylinders). ToF‐SIMS characterization on BCP is in good agreement with XPS analysis performed on the same samples. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
37.
Wenjuan Cheng Lu‐Tao Weng Yongjie Li Arthur Lau Chak Chan Chi‐Ming Chan 《Surface and interface analysis : SIA》2014,46(7):480-488
Size‐segregated particles were collected with a ten‐stage micro‐orifice uniform deposit impactor from a busy walkway in a downtown area of Hong Kong. The surface chemical compositions of aerosol samples from each stage were analyzed using time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS) operated in the static mode. The ToF‐SIMS spectra of particles from stage 2 (5.6–10 µm), stage 6 (0.56–1 µm), and stage 10 (0.056–0.1 µm) were compared, and the positive ion spectra from stage 2 to stage 10 were analyzed with principal component analysis (PCA). Both spectral analysis and PCA results show that the coarse‐mode particles were associated with inorganic ions, while the fine particles were associated with organic ions. PCA results further show that the particle surface compositions were size dependent. Particles from the same mode exhibited more similar surface features. Particles from stage 2 (5.6–10 µm), stage 6 (0.56–1 µm), and stage 10 (0.056–0.1 µm) were further selected as representatives of the three modes, and the chemical compositions of these modes of particles were examined using ToF‐SIMS imaging and depth profiling. The results reveal a non‐uniform chemical distribution from the outer to the inner layer of the particles. The coarse‐mode particles were shown to contain inorganic salts beneath the organics surface. The accumulation‐mode particles contained sulfate, nitrate, ammonium salts, and silicate in the regions below a thick surface layer of organic species. The nucleation‐mode particles consisted mainly of soot particles with a surface coated with sulfate, hydrocarbons, and, possibly, fullerenic carbon. The study demonstrated the capability of ToF‐SIMS depth profiling and imaging in characterizing both the surface and the region beneath the surface of aerosol particles. It also revealed the complex heterogeneity of chemical composition in size and depth distributions of atmospheric particles. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
38.
This paper presents a systematic X‐ray photoelectron spectroscopy (XPS)study of the Ni silicides Ni3Si, Ni31Si12, Ni2Si, NiSi and NiSi2 produced by annealing of sputtered thin films. The in situ XPS study focuses on both the core level peaks and Auger peaks. The peak positions, shapes, satellites as well as Auger parameters are compared for different silicides. The factors that influence the Ni core level peak shifts are discussed. The Ni 2p3/2 peak shape and satellites are correlated with the valence band structure. The effect of argon ion etching on surface composition and chemical states is also investigated. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
39.
R. W. Paynter 《Surface and interface analysis : SIA》2009,41(7):595-601
Polystyrene films were exposed to nitrogen plasmas for periods up to 8 min. Angle‐resolved X‐ray photoelectron spectroscopy measurements revealed the presence of oxygen and nitrogen in the surface due to the plasma treatment. The depth profiles of these adatoms were determined by fitting a regularized multipoint linear segment model to the data. A regularization parameter chosen such that the chi‐square statistic of the fit to the data was equal to the number of independent data points gave a more intuitive result than a parameter chosen according to the L‐curve criterion. Although the shape of the nitrogen depth profile was observed to vary as a function of the plasma duration, the oxygen depth profiles were nearly identical. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
40.
N. Nieuwjaer C. Poleunis A. Delcorte P. Bertrand 《Surface and interface analysis : SIA》2009,41(1):6-10
In this contribution, we focus on the use of C60+ ions for depth profiling of model synthetic polymers: polystyrene (PS) and poly(methylmethacrylate) (PMMA). These polymers were spin coated on silicon wafers, and the obtained samples were depth‐profiled both with Ga+ ions and C60+ ions. We observed an important yield enhancement for both polymers when C60+ ions are used. More specifically, we discuss here the decrease in damage obtained with C60, which is found to be very sensitive to the nature of the polymer. During the C60+ sputtering of the PMMA layer, after an initial decrease, a steady state is observed in the secondary ion yield of characteristic fragments. In contrast, for PS, an exponential decrease is directly observed, leading to an initial disappearance cross section close to the value observed for Ga+. Though there is a significant loss of characteristic PS signal when sputtering with C60+ ions beams, there are still significant enhancements in sputter yields when employing C60+ as compared to Ga+. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献