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191.
Petra Bombicz Birger Dittrich Marianna Strumpel Hans‐Peter Nabein Peter Luger 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(12):1447-1449
The structure of glycyl‐dl ‐leucine, C8H16N2O3, has been determined at 120 K by single‐crystal X‐ray diffraction. In addition to three N—H?O‐type hydrogen bonds of the positively charged RNH3+ group of the zwitterionic molecule, an intermolecular N—H?O contact exists between the peptide bond and the carboxylate group. Four hydrogen‐bond cycles were identified, giving a complex pattern. 相似文献
192.
Herein, we report a polymer cell using high-energy lithium metal anode, a composite sulfur-carbon cathode, and polyethylene oxide (PEO)-lithium trifluoromethan sulfonate (LiCF3SO3) electrolyte. The limited cost of raw materials as well as the very simple synthetic procedures, involving planetary ball milling (for S-C cathode) and solvent casting (for PEO-electrolyte), are expected to reflect into remarkable reduction of the economic impact of the proposed battery. Furthermore, the high energy of the Li-S cell and safety of the polymer configuration represent additional bonuses of the system. The S-C material, revealing a maximum capacity as high as 700 mAh g?1 in liquid electrolyte, is employed in a lithium-sulfur battery with the polymer configuration. The polymer cell delivers a capacity of 450 mAh g?1 at a voltage of about 2 V; hence, a theoretical energy density of 900 Wh kg?1 that may reflect into a high practical value, suitable for energy storage applications. 相似文献
193.
194.
The paper analyzes the dynamical behavior of a single degree of freedom (SDOF) passive magnetic suspension realized coupling traditional springs with rare-earth permanent magnets. The natural frequency of the device depends weakly on the mass due to the strongly non-linear magnetic repulsive force. The system exhibits features typical of non-linear oscillators, such as jump phenomena and multivalued frequency-response curves. In fact, for appropriate combinations of the parameters, multiple steady-state solutions appear. The periodic stationary solutions and the stability properties are investigated numerically and with a semi-analytical approach. Finally, comparisons with experimental results have been reported. 相似文献
195.
D. Carbone A. Bonaccorso C. Agodi M. Bondì F. Cappuzzello M. Cavallaro A. Cunsolo M. De Napoli A. Foti D. Nicolosi S. Tropea 《Bulletin of the Russian Academy of Sciences: Physics》2014,78(7):607-610
A study of the continuum of 14C populated by the 12C(18O, 16O)14C reaction at 84 MeV incident energy has been performed. The ejectiles have been momentum analyzed at forward angles by the MAGNEX magnetic spectrometer. The energy spectra were obtained up to about 20 MeV excitation energy. The scattering of two neutrons independently removed from the projectile as it passes the target nucleus has been described by means of an optical potential with a semi-classical approximation for the relative motion. The calculations describe a significant part of the continuum observed in the energy spectra. In particular, a resonance of the residual nucleus dominates the region near the two-neutron emission threshold. 相似文献
196.
M. Bondì F. Cappuzzello C. Agodi D. Carbone M. Cavallaro A. Cunsolo M. De Napoli A. Foti D. Nicolosi S. Tropea 《Bulletin of the Russian Academy of Sciences: Physics》2014,78(7):605-606
A study about the 12C(18O, 16O)14C two-neutron transfer reaction was performed at the Catania INFN-LNS laboratory at 84 MeV incident energy. The 16O ejectiles produced in the reactions were momentum analyzed and identified by the MAGNEX spectrometer. The Q-value spectrum of 14C shows several known bound and resonant states, in particular states with 2p-4h configuration respect to the 16O core. The integrated cross sections show an enhanced yield for the two-neutron transfer compared to the one-neutron transfer. These results are some experimental evidences that the (18O, 16O) reaction proceeds mainly by the direct transfer of the neutron pair, instead of a second order process. 相似文献
197.
198.
Arianna Tocchetti Sonia Maffioli Marianna Iorio Silke Alt Emma Mazzei Cristina Brunati Margherita Sosio Stefano Donadio 《Chemistry & biology》2013,20(8):1067-1077
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199.
This review covers applications of pristine and functionalized single-wall carbon nanotubes (SWCNTs) in nano-medicine, cultural heritage, and biosensors. The physicochemical properties of these engineered nanoparticles are similar to those of ultrafine components of airborne pollution (UF) and might have similar adverse effects. UF may impair cardiovascular autonomic control (inducing a high-risk condition for adverse cardiovascular effects), cause mammalian embryo toxicity, and increase geno-cytotoxic risk. SWCNTs coated with a biopolymer, for example polyethylenimine (PEI), become extremely biocompatible, hence are useful for in-vivo and in-vitro drug delivery and gene transfection. It is also possible to successfully immobilize a human enteric virus on PEI/SWCNT composites, suggesting application as a carrier in non-permissive media. The effectiveness of carbon nanostructured materials in the cleaning, restoration, and consolidation of deteriorated historical surfaces has been widely shown by the use of carbon nanomicelles to remove black dendritic crust from stone surfaces. The nanomicelles, here, have the twofold role of delivery and controlled release of the cleaning agents. The high biocompatibility of functionalized SWCNTs with enzymes and proteins is a fundamental feature used in the assembly of electrochemical biosensors. In particular, a third-generation protoporphyrin IX-based biosensor has been assembled for amperometric detection of nitrite, an environmental pollutant involved in the biodeterioration and black encrustation of historical surfaces. 相似文献
200.
Marianna Carbone M. Letizia Ciavatta Gianluca De Rinaldis Francesco CastelluccioErnesto Mollo Margherita Gavagnin 《Tetrahedron》2014
The re-investigation of the Mediterranean opisthobranch Thuridilla hopei resulted in the isolation and chemical characterization of three novel nor-diterpene aldehydes, nor-thuridillonals 2–4, structurally related to co-occurring already reported thuridillins. Analogous with the thuridillins, the new molecules were thought to derive from the same dietary precursor epoxylactone 1. 相似文献