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141.
Temperature measurements of shock heated materials using multispectral pyrometry: Application to bismuth 总被引:1,自引:0,他引:1
A new device for temperature measurements of shock heated materials has been developed in order to refine their equations
of state. We present temperature measurements for bismuth samples in contact with a lithium fluoride window. The shock pressure
of these experiments ranges from 18 to 97 GPa.
Received 2 June 1997 / Accepted 26 January 1998 相似文献
142.
The preparation of various (hex-5-ynyl)silanes was achieved following two different synthetic approaches from readily available materials such as 4-bromobutene, 6-iodohexyne and chlorosilanes. Different reaction conditions for intramolecular hydrosilylation were tested to prepare the corresponding 2-methylidene-1-silacyclohexanes. Notably, the use of Speier’s catalyst allowed the regioselective formation of the desired products in moderate yields. 相似文献
143.
The decisions of economic firms are often guided by simple routines. We demonstrate that such a routine may generate suboptimal chaotic dynamics, where the suboptimality is due to the fact that decision outcomes are in regions of low performance. We discuss a simple, but effective, method to regulate such dynamics in order to improve the performance. The method works as follows: In a first step, from time series information one has to identify critical starting areas which may lead to a crash or an outcome with low performance. In a second step, one has to perturb the system when it enters these critical areas. Due to sensitive dependence on initial conditions, already minor interventions suffice to prevent harmful events and to obtain better results. 相似文献
144.
Control of crystalline phases in magnetic Fe nanoparticles inserted inside a matrix of porous carbon
M.P. Fernández D.S. Schmool A.S. Silva M. Sevilla A.B. Fuertes P. Gorria J.A. Blanco 《Journal of magnetism and magnetic materials》2010,322(9-12):1300-1303
Two magnetic composites made up of Fe nanoparticles (Fe-NPs) embedded in a porous amorphous carbon matrix are presented. One of the samples, Fe-S-AC, was obtained with the aid of sucrose and the other, Fe-AC, in the absence of this substance. The XRD patterns show Bragg diffraction peaks associated with α-Fe and γ-Fe crystalline phases in the Fe-AC sample, while only peaks corresponding to the α-Fe phase are observed for Fe-S-AC powders. The Fe-NPs exhibit broad particle-size distributions for both samples, 5–50 nm for Fe-AC, whereas two populations (2–8 and 10–70 nm) for the Fe-S-AC composite are found. This fact gives rise to poorly defined blocking temperatures, as it can be deduced from the broad maxima observed in MZFC(T) variations. In addition, M(H) curves for both Fe-AC and Fe-S-AC samples reveal the existence of exchange-bias effect for T<60 K, probably due to a magnetic coupling within a core/shell structure of the Fe-NPs, although this effect was observed to be less significant for Fe-S-AC. 相似文献
145.
Claudio A. Téllez S. Sergio G. de la Riva Eduardo Hollauer Ionel Haiduc Cristian S. Silvestru 《光谱学快报》2013,46(7):1469-1483
Abstract The infrared and Raman spectra of dimethyldithiophosphinate anion (CH3)2PS2 were measured and the vibrational modes for the anion complex were assigned. A Normal Coordinate Analysis in the Modified General Valence Force Field (MGVFF) approximation was carried out assuming C2v symmetry. Ab Initio Calculations at RHF and MP2 level were also carried out for the anion geometry as well as for its frequencies, intensities and force constants. 相似文献
146.
Cristian D. Popescu 《Mathematische Nachrichten》2009,282(10):1370-1390
147.
Cristian Conde 《Linear algebra and its applications》2008,429(4):819-834
The aim of this work is to apply the complex interpolation method to norms of n-tuples of operators in a symmetrically-normed ideal J?⊆B(H) defined by a ? symmetric norming function (s.n.f.). The norms considered define Finsler metrics in a certain manifold of positive operators, and can be regarded as weighted ?-norms, the weight being a positive invertible operator. 相似文献
148.
149.
Dana Copolovici Cristian Silvestru Richard A. Varga 《Acta Crystallographica. Section C, Structural Chemistry》2008,64(1):m37-m39
The title compound, [Sb(C11H14NO)3], is monomeric with the Sb atom located on a threefold axis. The complex exhibits distorted trigonal–antiprismatic geometry around the Sb atom, owing to the presence of intramolecular N→Sb interactions. H...phenyl intermolecular interactions lead to the formation of dimers stacked along the c axis. The morpholine rings exhibit almost ideal chair conformations. No intermolecular interactions between the morpholine rings of neighbouring molecules were observed. 相似文献
150.
Ricardo Alcántara Pedro Lavela Gregorio Ortiz Inés Rodríguez José L. Tirado 《Hyperfine Interactions》2008,187(1-3):13-17
Cobalt–tin intermetallic compounds with different particle size have been obtained and characterized by using 119Sn Mössbauer spectroscopy as a main tool. The electrochemical behavior of the Co–Sn compounds has been evaluated in lithium test cells. The Lamb–Mössbauer factors for CoSn with different crystallite sizes have been calculated. The results f nano???CoSn(300 K) = 0.19 and f coarse???CoSn(300 K) = 0.55 are obtained. Nano-CoSn exhibits larger capacity to react with lithium than coarse-CoSn. 相似文献