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591.
Simone Cristoni Lorenzo Zingaro Cristina Canton Paola Cremonesi Bianca Castiglioni Stefano Morandi Milena Brasca Massimo Luzzana Cristina Battaglia 《Journal of mass spectrometry : JMS》2009,44(10):1482-1488
Surface‐activated chemical ionization (SACI) has been widely used in recent years for the analysis of different compounds (e.g. peptides, street drugs, amino acids). The main benefits of this technology are its high sensitivity and its effectiveness under different chromatographic conditions [i.e. ion exchange chromatography and reversed‐phase (RP) chromatography]. Here we used SACI in conjunction with quadrupole time‐of‐flight mass spectrometry to analyze enterotoxin A, which is produced by Staphylococcus aureus, in milk matrix using both RP and ion exchange chromatographies. SACI had increased sensitivity as compared with electrospray ionization. Moreover, the higher quantitation efficiency of this technique, mainly in terms of limit of detection (0.01 ng/ml), limit of quantitation (0.05 ng/ml), linearity range (0.05–50 ng/ml), matrix effect, accuracy (intraday and interday accuracy errors were 9.2% and 10.3%, respectively) and precision (intraday and interday precision errors were 5.3% and 12.8%, respectively), is shown and discussed. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
592.
Fabien Morel 《K-Theory》2005,35(1-2):1-68
593.
D. Elia G. E. Bruno M. Caselle R. A. Fini V. Lenti V. Manzari V. Paticchio R. Santoro G. Anelli M. Burns I. A. Cali M. Campbell S. Ceresa P. Chochula J. Conrad S. Kapusta A. Kluge M. Morel P. Nilsson F. Osmic P. Riedler G. Stefanini C. Torcato de Matos F. Antinori R. Dima D. Fabris M. Lunardon S. Moretto A. Pepato F. Scarlassara G. Segato R. Turrisi G. Viesti A. Badalà F. Librizzi G. S. Pappalardo A. Pulvirenti F. Riggi M. Cinausero E. Fioretto G. Prete L. Vannucci M. Krivda L. Sándor F. Soramel T. Virgili 《Czechoslovak Journal of Physics》2005,55(12):1635-1638
The silicon pixel detector (SPD) comprises the two innermost layers of the inner tracking system oft he ALICE experiment at
LHC. Prototype SPD assemblies have been tested in high-energy proton and pion beams at the CERN SPS. The method used for data
analysis and the most relevant results in relation to detector performance are presented.
Presented in the Poster Session “Future Experiments and Facilities” at the 18th International Conference “Quark Matter 2005”,
Budapest, Hungary, 4–9 August 2005.
On behalf of the Silicon Pixel Detector project in the ALICE Collaboration 相似文献
594.
The thirty years old programme of Griffiths and Harris of understanding higher-dimensional analogues of Poncelet-type problems and synthetic approach to higher genera addition theorems has been settled and completed in this paper. Starting with the observation of the billiard nature of some classical constructions and configurations, we construct the billiard algebra, that is a group structure on the set T of lines simultaneously tangent to d−1 quadrics from a given confocal family in the d-dimensional Euclidean space. Using this tool, the related results of Reid, Donagi and Knörrer are further developed, realized and simplified. We derive a fundamental property of T: any two lines from this set can be obtained from each other by at most d−1 billiard reflections at some quadrics from the confocal family. We introduce two hierarchies of notions: s-skew lines in T and s-weak Poncelet trajectories, s=−1,0,…,d−2. The interrelations between billiard dynamics, linear subspaces of intersections of quadrics and hyperelliptic Jacobians developed in this paper enabled us to obtain higher-dimensional and higher-genera generalizations of several classical genus 1 results: Cayley's theorem, Weyr's theorem, Griffiths-Harris theorem and Darboux theorem. 相似文献
595.
Zlatan Denchev Milena Tomanova Albena Lederer 《Journal of polymer science. Part A, Polymer chemistry》2008,46(15):5142-5156
Ethyl‐(ECA) and butyl‐2‐cyanoacrylate (BCA) monomers of high purity and acidic stabilization were synthesized and anionically polymerized to homo‐ and copolymers in two different ways: by piperidine‐catalyzed bulk polymerization leading to transparent, brittle films (method A) and by polymerization in aqueous medium in the presence of sodium bicarbonate to obtain white powders (Method B). The molecular structure of the synthesized monomers, homopolymers and copolymers were corroborated by spectral methods. The polymers were studied further by thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), size exclusion chromatography (SEC) and proton nuclear magnetic resonance (1H NMR). Controlling the composition of the monomer feed and the way the polymerization was performed, it was possible to obtain phase separated or homogeneous cyanoacrylate copolymers with glass transitions varying between the Tg of polyECA and that of polyBCA. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5142–5156, 2008 相似文献
596.
I. Crassous H. Groult F. Lantelme D. Devilliers A. Tressaud C. Labrugère M. Dubois C. Belhomme A. Colisson B. Morel 《Journal of fluorine chemistry》2009,130(12):1080-1085
During the electrolysis of molten KH-2HF, a solid CF film is formed on carbon anodes. The influence of the potential applied to the anode on the composition of the CF surface film was studied by XPS and NMR. Results obtained with carbon electrochemically passivated in molten KF-2HF have been compared with those obtained with carbon simply immersed in molten KF-2HF without any polarization. Whatever the potential, and even in the case of carbon sample immersed in molten KF-2HF without any polarization, the presence of covalent and semi-ionic C–F bonds has been pointed out both by XPS and NMR. For polarized samples, the higher the potential applied to the anode in KF-2HF, the higher the fluorination level. From investigations carried out with carbon activated at 40 V in molten KF-2HF, it was concluded that the electropolishing of the surface induced by this treatment allows enhancing drastically the fluorine evolution reaction. 相似文献
597.
Adriaan M. H. van der Veen Milena Horvat Radmila Milačič Tinkara Bučar Urška Repinc Janez Ščančar Radojko Jaćimović 《Accreditation and quality assurance》2001,6(6):264-268
A proficiency test (PT) was carried out to investigate the quality of laboratory results measuring trace elements in sewage sludge. The scheme relied on reference values, established through flame atomic absorption spectroscopy and instrumental neutron activation analysis. Within the framework of the project, ”Proficiency testing in Central and Eastern European Countries”, the measurements were done in parallel using induced coupled plasma mass spectrometry. This paper discusses the design of the PTS, the metrological concepts behind it and the way in which it was operated. The discussion includes the estimation of measurement uncertainty of the reference values obtained, homogeneity testing and its uncertainty evaluation, as well as all relevant quality assurance aspects. From the results, it can be concluded that all measurement methods involved agree within their respective uncertainties. Furthermore, it can be concluded that it is feasible to operate a proficiency test of trace elements in sewage sludge using reference values. The agreement between the reference values and the consensus values is satisfactory. 相似文献
598.
We continue investigations of ?ech closure spaces and their hyperspaces started in [M. Mrševi?, M. Jeli?, Selection principles and hyperspace topologies in closure spaces, J. Korean Math. Soc. 43 (2006) 1099-1114] and [M. Mrševi?, M. Jeli?, Selection principles, γ-sets and αi-properties in ?ech closure spaces, Topology Appl., in press], focusing on generalized upper and lower Vietoris topologies. 相似文献
599.
We studied the friction properties of four model silicate materials at the nanoscale and microscale. From nanotribology, we characterized the tribological properties at single asperity contact scale and from microtribology, we characterized the tribological properties at multi asperity contact scale. First, for each material we measured chemical composition by XPS, Young's modulus by acoustical microscopy and roughness σ by atomic force microscopy (AFM). Second, we measured the nanofriction coefficients with an AFM and the microfriction coefficients with a ball probe tribometer, for three hardnesses of the ball probe. We identified one friction mechanism at the nanoscale (sliding friction) and two friction mechanisms at the microscale (sliding friction and yielding friction). Comparison of the nano and microfriction coefficients at the same sliding friction regime shown, that the tribological properties of these materials didn’t depend on roughness. 相似文献
600.
Jacopo Vialetto Manos Anyfantakis Sergii Rudiuk Mathieu Morel Damien Baigl 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(27):9243-9247
Control over particle interactions and organization at fluid interfaces is of great importance both for fundamental studies and practical applications. Rendering these systems stimulus‐responsive is thus a desired challenge both for investigating dynamic phenomena and realizing reconfigurable materials. Here, we describe the first reversible photocontrol of two‐dimensional colloidal crystallization at the air/water interface, where millimeter‐sized assemblies of microparticles can be actuated through the dynamic adsorption/desorption behavior of a photosensitive surfactant added to the suspension. This allows us to dynamically switch the particle organization between a highly crystalline (under light) and a disordered (in the dark) phase with a fast response time (crystallization in ≈10 s, disassembly in ≈1 min). These results evidence a new kind of dissipative system where the crystalline state can be maintained only upon energy supply. 相似文献