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Marinopoulos AG Reining L Olevano V Rubio A Pichler T Liu X Knupfer M Fink J 《Physical review letters》2002,89(7):076402
We determined the anisotropic dielectric response of graphite by means of time-dependent density-functional theory and high-resolution valence electron energy-loss spectroscopy. The calculated loss function was in very good agreement with the experiment for a wide range of momentum-transfer orientations with respect to the graphitic basal planes, provided that local-field effects were included in the response. The calculations also showed strong effects of the interlayer Coulomb interaction on the total pi+sigma plasmon. This finding must be taken into account for the explanation of recent loss spectra of carbon nanotube materials. 相似文献
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Coupled Multiscale Simulation and Optimization in Nanoelectronics project isaMarie Curie RTN supported by the European Commission within the 6th Framework Research Programme of the EU. The COMSON project is run by a Consortium whose multiple aims are: to build an experimental software Demonstrator Platform (DP) for coupled simulation of devices, interconnects, circuits, EM fields and thermal effects (one single framework for simulation tool, optimisation in compound design space); to provide an e-learning platform to be used as an inter and extra consortium transfer of knowledge (ToK) infrastructure; to provide a collaborative virtual work environment (CWE) to be used both for industrial activities and training. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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Journal of Statistical Physics - Linear response theory, originally formulated for studying how near-equilibrium statistical mechanical systems respond to small perturbations, has developed into a... 相似文献
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Maurizio Corradini Masaki Hori Takumi Kobayashi Marco Leali Evandro Lodi-Rizzini Valerio Mascagna Aldo Mozzanica Michela Prest Anna Soter Koichi Todoroki Erik Vallazza Luca Venturelli Nicola Zurlo 《Hyperfine Interactions》2012,213(1-3):31-39
The results of the annihilation cross sections measurement of 5.3 MeV antiprotons on nickel, tin, platinum and Mylar targets performed by the ASACUSA Collaboration at CERN are presented and compared with the existing data and models. From the experimental point of view the presented data are the first measurement of antinucleon annihilation cross sections at low energies obtained with a pulsed beam. This results open the road for the next measurements at the very low energies of the order of 100 keV that are in progress by the ASACUSA Collaboration. The experimental method foreseen for the 100 keV measurement is illustrated. 相似文献
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Andrea Cingolani Valerio Zanotti Stefano Zacchini Massimiliano Massi Peter V. Simpson Nima Maheshkumar Desai Ilaria Casari Marco Falasca Luca Rigamonti Rita Mazzoni 《应用有机金属化学》2019,33(4)
Neutral and cationic cyclopentadienone (CpO) N‐heterocyclic carbene (NHC) bis‐carbonyl iron(0) complexes bearing, appended to the NHC ligand, either a terminal amino group on the lateral chain, [Fe(η4‐CpO)(CO)2(κC‐NHC(CH2)nNH2)] with n = 2 ( 2a ) and 3 ( 2b ), or a cationic NMe3+ fragment, [Fe(η4‐CpO)(CO)2(κC‐NHC(CH2)2NMe3)](I) ( 3 ), were prepared and characterized in terms of their structure, stability and reactivity. The photochemical properties of 2a and 2b were examined both in organic solvents and in water, revealing the photoactivated release of one CO ligand followed by the formation of the chelated complex [Fe(η4‐CpO)(CO)(κ2C,N‐NHC(CH2)2NH2)] ( 4 ), whose molecular structure was confirmed by single crystal X‐ray diffraction studies. This metallacyclization occurs only in the case of 2a , with the ethylene spacer between NHC ring and NH2 group in the lateral chain, allowing the formation of a stable 6‐membered ring. On the other hand, 2b undergoes decomposition upon irradiation. The reactivity in aqueous solutions revealed the chemical speciation of the complexes at different pH and especially under physiological conditions (phosphate buffer solution at pH 7.4 and 37 °C). The lack of data on the biological properties of iron(0) complexes prompted us to preliminarily investigate their cytotoxicity against model cancer cells (AsPC‐1 and HPAF‐II), along with a determination of their lipophilicity. 相似文献
147.
Valerio Di Lisio Elisa Sturabotti Iolanda Francolini Antonella Piozzi Andrea Martinelli 《Journal of Polymer Science.Polymer Physics》2019,57(14):922-931
Modulated temperature techniques allow to separate the reversing and non‐reversing contributions of material transitions. To investigate reversible crystallization and melting of isotactic polypropylene (iPP) at microstructural level, in this research, modulated temperature Fourier transform infrared (MTFTIR) and quasi‐isothermal FTIR (QIFTIR) analyses are used. By following the intensity variation of iPP regularity bands, associated with 31 helix structures of different lengths (n repeating units), MTFTIR evidences that, independently from helix length, a reversing coil–helix transition takes place few degrees below the non‐reversing crystallization onset. By comparing spectroscopic and differential scanning calorimetry experiments performed in quasi‐isothermal conditions, the reversing transition was found to be associated with the reversible melting‐crystallization phenomenon. Moreover, QIFTIR evidences that helices of different lengths contribute differently to the reversible transition: the helices composed of n = 10 and n = 12 are active into all the explored temperature range (30–130 °C) whereas the shortest (n = 6) and the longest (n > 15) helices contribute to reversibility at T > 100 °C. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019 , 57, 922–931 相似文献
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The voltammetric behaviour of selenium(IV) was studied at platinum and gold electrodes in sulphuric acid, perchloric acid and potassium chloride media as a basis for its voltammetric detection. The best voltammetric behaviour was recorded at gold electrodes with perchloric acid as the supporting electrolyte. The concomitant presence of metals, such as copper or lead, and of model biomolecules, such as bovine serum albumin, in the solution resulted in a deterioration of the electrochemical response for selenium(IV). Quantitative detection of selenium(IV) by square wave anodic stripping voltammetry at both a millimetre-sized gold disc electrode and a microband electrode array revealed linear responses to selenium concentration in the ranges 5–15 μM and 0.1–10 μM, respectively, with 60 s preconcentration. The sensitivities were 6.4 μA μM−1 cm−2 and 100 μA μM−1 cm−2 at the disc and the microband array, respectively. The detection limit at the microband electrode array was 25 nM, illustrating the potentiality of such microelectrodes for the development of mercury-free analytical methods for the trace detection of selenium(IV). 相似文献