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171.
We propose a non-iterative MUSIC (MUltiple SIgnal Classification)-type algorithm for the time-harmonic electromagnetic imaging of one or more perfectly conducting, arc-like cracks found within a homogeneous space R2. The algorithm is based on a factorization of the Multi-Static Response (MSR) matrix collected in the far-field at a single, nonzero frequency in either Transverse Magnetic (TM) mode (Dirichlet boundary condition) or Transverse Electric (TE) mode (Neumann boundary condition), followed by the calculation of a MUSIC cost functional expected to exhibit peaks along the crack curves each half a wavelength. Numerical experimentation from exact, noiseless and noisy data shows that this is indeed the case and that the proposed algorithm behaves in robust manner, with better results in the TM mode than in the TE mode for which one would have to estimate the normal to the crack to get the most optimal results. 相似文献
172.
Jun Zhou Yong-zhi Qiu Xiao-peng Zang Chang-wang Pan Qiang Chen Jian Shen Si-cong Lin 《高分子科学》2005,23(1)
N,N-dimethyl-N-methacryloyloxyethyl-N-carboxyethyl ammonium (DMMCA) was graft-copolymerized onto the surface of segmented poly(ether urethane) (SPEU) and PE film. The carboxybetaine structure on SPEU and PE film surfaces was confirmed by ATR-FTIR, XPS and water contact angle measurements. Through the experiments with platelet adhesion and protein adhesion assay in vitro, the two materials studied, including poly-DMMCA gel, all show excellent nonthrombogenicity. This confirms once again that the zwitterionic molecular structure on the surfaces of materials is essential for improving their nonthrombogenicity and biocompatibility. 相似文献
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174.
Diana Amorello Fabrizio Ledda Vincenzo Romano Roberto Zingales 《Journal of solution chemistry》2009,38(2):259-263
The determination of the Ti(IV,III) redox couple formal potential in 1 mol⋅dm−3 HCl, 2 mol⋅dm−3 NaCl medium at 25 °C through batch experiments involving the preparation of Ti(IV) and Ti(III) mixtures via the reaction
of Ti(IV) with zinc amalgam, has been carried out with Emf measurements in order to verify the correctness of the previous
value that the authors obtained by a coulometric-potentiometric investigation in the same conditions. The results from the
two independent methods are in good agreement: (9±1) mV by the first method and (9±2) mV by the average batch result. 相似文献
175.
176.
George G. Roussas Debasis Bhattacharya 《Statistical Inference for Stochastic Processes》2009,12(2):185-201
Under suitable regularity conditions imposed on a general discrete time-parameter stochastic process, the Hájek-Inagaki convolution
representation theorem is established for randomly stopped locally asymptotically mixed normal experiments.
D. Bhattacharya: On leave from Visva-Bharati University, Santiniketan, India. 相似文献
177.
This work presents a technique to simplify overcrowded proton spectra in chiral liquid crystal solvents using rotation of the sample near the magic angle, VASS, combined with homonuclear selective refocusing 2D NMR experiments, SERF. This methodology provides a powerful tool to visualise enantiomers out of unresolved proton spectra. A modified SERF sequence is presented where the resulting 2D spectrum can be phased to increase the resolution. Accurate enantiomeric excesses are determined that are not possible to measure on static samples. Two examples are presented. 相似文献
178.
Summary: FT Raman microspectroscopy was used for polarization experiments on strained hemp fibre cells. The cellulosic plant fibers were macerated with alkaline and enzymatic solutions. Those cleaned and refined single fiber cells were subjected to micro tensile tests as well as to polarization measurements under the FT Raman microscope. Mechanical parameters of the fiber cells (e.g. E-modulus) were determined and changes in orientation of the (C O C) structure units of the cellulose were considered with respect to fiber stress and molecular fiber structures. Intensity ratios R1 and R2 calculated on the polarized micro FT Raman spectra of the strained fibers describe the order parameter 〈P2〉 and 〈P4〉 allowing the quantitative determination of the orientation of the structure units (C O C) of fiber cellulose with respect to the fiber cell axis. 相似文献
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180.