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131.
M. Perez F. Perrard V. Massardier X. Kleber A. Deschamps H. de Monestrol 《哲学杂志》2013,93(20):2197-2210
Measuring the solubility limit of copper in iron at temperature lower than 700°C is problematic because copper diffusion is too slow in this temperature range. To overcome this difficulty, fine precipitation of copper is studied. The solubility limit of copper is measured after complete precipitation using two complementary techniques: thermoelectric power and small angle X-ray scattering. Values obtained are confirmed by tomographic atom probe and give results much higher than what is usually extrapolated from high-temperature experiments. 相似文献
132.
The refined grains in both as-cast Mg-10Y-1Zn-2Zr (WZ101?K, wt.%) and Mg-10Y-1Al (WA101, wt.%) alloys have been found to have superior thermal stability after solution treatment. Plate-shaped, but different polytypes of long-period stacking ordered (LPSO) phases distributed along grain boundaries are considered as the predominant inhibitors of grain growth. Based on the plate-shaped features of the LPSO phases, a modified Zener’s model is established and the predicted limiting grain sizes are in a good agreement with the experimental results. Therefore, this model has strong potential for designing advanced Mg-RE-based alloys with high strength and high creep resistance at high temperatures. 相似文献
133.
134.
We find a sufficient condition for the existence of surface (Rayleigh) waves based on the Rayleigh-Ritz variational method. When specialized to a homogeneous half-space, the sufficient condition recovers the known criterion for the existence of subsonic surface waves. A simple existence criterion in terms of material properties is obtained for periodic half-spaces of general anisotropic materials. Further, we numerically compute the dispersion relation of the surface waves for a half-space of periodic laminates of two materials and demonstrate the existence of surface wave band gaps. 相似文献
135.
Electron transport properties of an ideal one-dimensional (1D) quantum wire are studied including spatially periodic Rashba spin–orbit coupling (SOC) and Dresselhaus SOC. By comparing with the previous work [S.J. Gong, Z.Q. Yang, J. Phys. Condens. Matter 19 (2007) 446209], two transmission gaps appear in the transmission probability of electrons and their widths are also broadened dramatically. Moreover, it is found that their widths are sensitive not only to the strength of SOCs but also to the length ratio of SOCs segment and non-SOCs segment. In addition, a ‘circle-type’ transmission behavior has been found by tuning the strength of SOCs continuously. Our results may extend the previous work and provide an more effective method to manipulate the current in nanoelectric devices. 相似文献
136.
O.M. Lyulin V.I. Perevalov H. Tran J.-Y. Mandin V. Dana L. Rgalia-Jarlot X. Thomas D. Dcatoire 《Journal of Quantitative Spectroscopy & Radiative Transfer》2009,110(17):1815-1824
Using the Fourier transform spectra of the acetylene molecule recorded near 1.5-μm, the intensities of 111 lines belonging to seven hot bands of the main isotopologue 12C2H2 have been retrieved by means of a multispectrum fitting procedure. Considering the density of lines in the spectra, and the fact that the measured bands are the weakest observed, the accuracy of the measurements is around 10%. At first stage, an empirical treatment of these data has been performed, leading to the vibrational transition dipole moment squared and some Herman–Wallis coefficients. Then the measured line intensities of this work and collected ones from the literature have been treated simultaneously within the framework of the effective operator approach. 相似文献
137.
The photoreduction behavior of alkyl viologen compounds in a PVA matrix was investigated. The initial photoreduction of alkyl viologens and related polyviologens follows second-order reaction kinetics, and the respective rate constants, which vary only slightly with alkyl chain length, were determined. While the polymer effect was not remarkable in a PVA matrix, the association behavior of radical cations was similar to that found in a 2-propanol aqueous solution. 相似文献
138.
139.
W. Chen X. L. Xu P. Zhou Y. M. Cui Y. G. Li 《Russian Journal of Coordination Chemistry》2013,39(3):301-304
Two silver(I) compounds, [Ag(R,R-hxn)](C7H4BrO2) · 2H2O (I) (Chxn = 1,2-diaminocyclohexane) and [Ag(C5H6N2)2]2(C8H4O4) · 10H2O (II), were synthesized and complex I was structurally characterized by X-ray crystallography. Compound I contains a catena-(trans-1,2-diaminocyclohexane) silver polycation ([Ag(Chxn)]∞) in a roughly linear fashion, while II possesses a linear-type silver monocation. Compounds I and II were evaluated for their inhibitory activities against Helicobacter pylori urease in vitro. Both were found to have strong inhibitory activities against H. pylori urease comparable to that of acetohydroxamic acid. 相似文献
140.
Density functional theory (DFT) and the dispersion corrected DFT have been used to investigate the hygroscopicity of ammonium dinitramide (ADN). Calculation results show that the gaseous ADN has a strong hydrogen bond. But the ionic pair structure NH4 + · N(NO2)? is stabilized upon the addition of water molecules. Natural bond orbital calculations suggest that the intra- and intermolecular orbital interactions LP(O) → σ*(N–H) or LP(O) → σ*(O–H) make the system stabilized as a whole. En energy decomposition analysis reveals that the interactions between ADN and H2O are dominated by the electrostatic and orbital interactions. The formation reactions become more spontaneous with the increasing number of water molecules but can be weakened by the growing temperature from 200 to 400 K. Moreover, the molecular dynamic method is applied to explore a more realistic cluster model to study the interactions between ADN and H2O. 相似文献