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951.
952.
Pablo Salvador Julia Real Clara Zamorano Antonio Villanueva 《Mathematical and Computer Modelling》2011,53(1-2):42-54
In recent years, ground vibrations have become an important issue due to the growing awareness of the society about environmental living conditions. In this way, vibrations caused by trains running near houses or workplaces are considered disturbing for residents. Within this framework, this paper presents a procedure to estimate the vibration path caused by the passing of a train. In order to achieve this, the equations which describe the physical phenomenon are set in the frequency and wavenumber domain and solved by using the Fourier Transform. The obtained analytical solution is transformed back into the time and space domain by means of the Fourier series. The obtained theoretical results are compared with experimental measurements carried out in the Madrid–Barcelona High Speed Line in order to analyse the performance of this procedure. 相似文献
953.
954.
Antonio Martí nez-Abejó n 《Proceedings of the American Mathematical Society》1999,127(5):1397-1398
We give an elementary proof of the principle of local reflexivity.
955.
Anna Martínez‐Villalba Encarnación Moyano Maria T. Galceran 《Rapid communications in mass spectrometry : RCM》2009,23(9):1255-1263
Drugs that are used as medicines and also as growth promoters in veterinary care are considered as emerging environmental contaminants and in recent years concern about their potential risk to ecosystems and human health has risen. In this paper we used a method based on liquid chromatography/electrospray tandem mass spectrometry to analyze eight coccidiostatic compounds: diclazuril, dinitrocarbanilide (the main metabolite of nicarbazin), robenidine, lasalocid, monensin, salinomycin, maduramicin and nasarin. Multiple‐stage mass spectrometry (MSn) based on the precursor ions [M+Na]+ (polyether ionophores), [M+H]+ (robenidine) and [M–H]? (diclazuril and dinitrocarbanilide) was used to study the fragmentation of these compounds. MSn data and genealogical relationships were used to propose a tentative assignment of the different fragment ions. Loss of water, decarboxylations, ketone β‐cleavages and rearrangement of cyclic ethers and amide groups were some of the fragmentations observed for these compounds. Liquid chromatography with a sub‐2 µm particle size column was coupled to tandem mass spectrometry (LC/MS/MS) allowing the separation of these compounds in less than 7 min. Method detection limits ranging from 11 to 71 ng L?1 and run‐to‐run values in terms of relative standard deviation (RSD) (up to 12%) were obtained. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
956.
In this work, the experimental vapor pressures of four amines 1,2-bis(dimethylamino)ethane, 1-methylmorpholine, 1,2-bis(2-aminoethoxy)ethane and N-benzylethanolamine using a static apparatus are reported. The temperature range is comprised between 273.18 and 364.97 K and the pressure range between 0.782 Pa and 333 kPa. The molar enthalpies of vaporization at 298.15 K were calculated from Clausius–Clapeyron equation fitted on the experimental results. 相似文献
957.
A short note about exposed points in real banach spaces 总被引:1,自引:0,他引:1
Francisco J García-Pacheco 《数学物理学报(B辑英文版)》2008,28(4):797-800
We express the set of exposed points in terms of rotund points and non-smooth points.As long as we have Banach spaces each time"bigger",we consider sets of non-smooth points each time"smaller". 相似文献
958.
Resonating valence bond theory combined with DFT calculations permit to build a simple model for the dissociation of H2 on palladium surface. Based on analysis of the electron transfer and total energy for different geometries of the Pd2–H2 and Pd5–H2 systems it is found that the predissociative state corresponds to a tilted molecule adsorbed on the surface. 相似文献
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960.