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41.
We extend a recent result of Ricceri concerning the existence of three critical points of certain non-smooth functionals.
Two applications are given, both in the theory of differential inclusions; the first one concerns a non-homogeneous Neumann
boundary value problem, the second one treats a quasilinear elliptic inclusion problem in the whole
\mathbb RN{\mathbb R^N}. 相似文献
42.
An automated setup for impedance measurements of NOX sensors and sensor elements has been assembled. The NOX atmosphere is generated using NO and NO2 calibration mixtures and N2. The mixture is passed to the measurement chamber, where impedance measurements are performed. The sample can be subjected
to temperature between 50 and 800 °C. The gas mixture is passed to the chemiluminescence analyser, where NOX and NO amount is determined. The automation is based on National Instruments LabView programming language. Gas flow control,
impedance measurement and NOX level analysis can be simultaneously performed using a single PC computer.
Paper presented at the Patras Conference on Solid State Ionics — Transport Properties, Patras, Greece, Sept. 14 – 18, 2004. 相似文献
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Marcin Sobczak Tadeusz Chreptowicz Joanna Kolmas Waclaw Kolodziejski 《Solid state nuclear magnetic resonance》2009,35(4):230-234
Commercial Dexon surgical sutures, made of polyglycolide (PGA), were examined using 13C CP/MAS NMR. The study shows that detailed analysis of the cross-polarization (CP) process is useful in the peak assignments and in the assessment of molecular mobility in the polymer domains. Crystallinity of PGA in the sutures was estimated at ca. 55%. 相似文献
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Waclaw Tomaszewski Andrzej Duda Marek Szadkowski Jan Libiszowski Danuta Ciechanska 《Macromolecular Symposia》2008,272(1):70-74
Summary: The electrospinning technique based on single and multi-jet systems was applied for poly(L -lactide) (PLA) nano- and microfibers as well as fibrous mats manufacture; the latter with dimensions suitable for the tensile tests. The PLA's employed were prepared by the controlled ring-opening polymerization of the L,L -lactide (LA) monomer. The resulting fibers thickness was correlated with molecular weights of PLA's and viscosities of spinning solutions. The scanning electron microscopic, thermal, and tensile characteristics of the polymeric materials and fibrous mats were also examined. 相似文献
46.
Waclaw Sierpinski 《Annali di Matematica Pura ed Applicata》1955,39(1):69-74
Résumé L'auteur donne des conditions nécessaires et suffisantes pour qu'un nombre naturel n soit un ? nombre pratique ?, c'est-à-dire
pour que tout nombre naturel <-n soit une somme de diviseurs naturels distincts du nombre n.
à Mauro Picone pour son 70me anniversaire. 相似文献
47.
Kolmas J Slósarczyk A Wojtowicz A Kolodziejski W 《Solid state nuclear magnetic resonance》2007,32(2):53-58
Specific surface areas of apatites in whole human mineralized tissues were estimated from (31)P MAS NMR linewidths: 77 m(2)g(-1) for enamel and 94 m(2)g(-1) for dentin, dental cementum and cortical bone. 相似文献
48.
Kolodziejski W Herold J Kuras M Wawrzycka-Gorczyca I Koziol AE 《Solid state nuclear magnetic resonance》2011,39(3-4):41-46
The (1)H→(13)C NMR cross-polarization (CP) was studied under magic-angle spinning at 7.5 kHz in various crystal forms of the antipsychotic drug olanzapine: two polymorphs (metastable I and stable II) and eight solvates containing organic solvent and water molecules. The CP kinetics followed the non-classical I-I(*)-S model, in which CP begins in a spin cluster of proximate abundant spins I(*) and rare spins S, then is controlled by spin diffusion of the abundant spins I from bulk to the I(*) spins of the spin cluster and finally is governed by spin-lattice relaxation of the abundant spins in the rotating frame. The corresponding CP kinetics parameters were determined and analyzed. It was demonstrated that the, λ and T(df) values (the CP time constant, the cluster composition parameter and the (1)H spin-diffusion constant, respectively) were very useful to discriminate the functional groups, especially in the 3D parameter space. In order to conveniently analyze the large amount (175) of the collected CP parameters, the number of the observed variables was reduced using the principal component (PC) analysis. The 2D plot of PC2 vs. PC1 showed adequate separation of the CH(3), CH(2), CH and C cases (C stands for carbons without adjacent hydrogens). It was demonstrated that those cases were located along the PC1 axis in the order of increasing (1)H-(13)C dipolar couplings: C相似文献
49.
Kinetics of NMR cross-polarization (CP) from protons to phosphorus-31 nuclei was studied in the following samples: mineral of whole human bone, apatite prepared from bone, natural brushite, synthetic hydroxyapatite (hydrated and calcined), and synthetic carbonatoapatite of type B with 9 wt% of CO(3) (2-). In order to avoid an effect of magic angle spinning on CP and relaxation, the experiments were carried out on static samples. Parameters of the CP kinetics were discussed for trabecular and cortical bone tissue from adult subjects in comparison to the synthetic mineral standards. It was found that carbonatoapatite shows similar CP behavior to the bone mineral. Both materials undergo two-component CP kinetics. The fast-relaxing classical component is from the surface of apatite crystals and the slow-relaxing nonclassical component comes from the crystal interior. The components have been unambiguously assigned using inverse CP from phosphorus-31 to protons. The study provides information on a structured water layer, which covers crystal surface of carbonato- and bone apatite. The layer encompasses ca 40% of apatite phosphorus and its thickness is more than ca 2 nm. 相似文献
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