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81.
Yang Pei 《Physica B: Condensed Matter》2012,407(22):4436-4439
The influences of strain to the energetic and electronic properties of graphdiyne are investigated based on first-principles calculations. The elastic parameters of graphdiyne are determined by total energy calculation. Compared to graphyne, graphdiyne is softer because it has less C–C bonds. Moreover, the band gap of graphdiyne is tunable under uniform strain. It monotonously increases with increasing strain value, which originates from the decreased orbital overlap between C atoms when strain increases. 相似文献
82.
83.
Chi-Sing Man Roberto Paroni Yu Xiang Edward A. Kenik 《Journal of Computational and Applied Mathematics》2006,190(1-2):200-210
Herein we derive an expression for direct determination of the geometric autocorrelation function W of a polycrystalline material from images of its grain boundary network (e.g., those delivered by orientation imaging microscopy). We also obtain an identity that relates the mean linear intercept function to a directional derivative of the geometric autocorrelation function. These formulae were applied to examine whether a widely-used formula for W, particularly in theoretical studies of attenuation of elastic waves in polycrystalline media, would be valid for the grain boundary structure of a commercial aluminum alloy. The conclusion was negative. 相似文献
84.
F. Kalarasse 《Journal of Physics and Chemistry of Solids》2006,67(4):846-850
We report on first-principles study of the structural and elastic properties of the Nowotny-Juza filled tetrahedral compounds LiZnX (X=N, P, As) using the full-potential linearized augmented plane wave method within the local density approximations. Our results indicate that the energetically favourable α-LiZnX materials are slightly softer than their binary analogous GaX and the sound speeds are quantitatively similar for LiZnAs and GaAs. 相似文献
85.
Giuseppe Saccomandi 《International Journal of Non》2004,39(2):331-339
By an extension of the usual Weierstrass discussion for first-order differential equations, we determine a simple criterion which allows us to determine when compact structures are possible in second-order wave equations. For higher-order wave equations, such as the modified improved Boussinesq equation, this criterion may still be used, but the appearance of an overdetermined system of differential equations which is not trivially satisfied, unlike in the second-order case, renders the possibility of compact structures a happenstance. 相似文献
86.
刘德辅 《数学物理学报(B辑英文版)》1995,(1)
(刘德辅)BEHAVIORASt→∞OFTHESOLUTIONSOFTHELINEARSYSTEMOFELASTICTHEORYONNON-STAR-SHAPEDEXTERIORDOMAINS¥LiuDefu(Dept.ofApplMath.,Bei... 相似文献
87.
Ultrasonic wave speed measurements are widely used to infer the elastic properties of solids. In the standard method, longitudinal
and shear transducers are used separately to measure the corresponding wave speeds in a material. A new experimental method
is introduced for simultaneously measuring the longitudinal and the shear wave speeds using a single set of longitudinal or
shear transducers. The method can also be used to measure the wave speeds in situ during deformation by placing the transducers along the loading axis. The transducers are housed in a specially designed
fixture such that they are not subjected to loading. The technique is demonstrated by performing uniaxial compression experiments
on fully dense isotropic solids (where the wave speeds are not expected to change during deformation) and in polymeric foams
(where the wave speeds are affected by damage). 相似文献
88.
Ping Luo 《计算数学(英文版)》2002,(1)
1. IntroductionIt is well known that contact problems have always occupied a position of special importancein the mechanics of solids. So it attracted particular attention of engineers and computationalexperts. In the last ten years, with the development … 相似文献
89.
I. K. Bensafa P. Achenbach M. Ases Antelo C. Ayerbe D. Baumann R. Böhm D. Bosnar E. Burtin X. Defaÿ N. D'Hose M. Ding M. O. Distler L. Doria H. Fonvieille J. M. Friedrich J. Friedrich J. García Llongo P. Janssens G. Jover Mañas M. Kohl G. Laveissière M. Lloyd M. Makek J. Marroncle H. Merkel P. Merle U. Müller L. Nungesser B. Pasquini R. Pérez Benito J. Pochodzalla M. Potokar G. Rosner S. Sánchez Majos M. Seimetz S. Širca T. Spitzenberg G. Tamas R. Van de Vyver L. Van Hoorebeke Th. Walcher M. Weis 《The European Physical Journal A - Hadrons and Nuclei》2007,32(1):69-75
The beam-helicity asymmetry has been measured simultaneously for the reactions
p→epγ and
p→epπ
0 in the Δ(1232)-resonance region at Q
2 = 0.35(GeV/c)2. The experiment was performed at MAMI with a longitudinally polarized beam and an out-of-plane detection of the proton. The
results are compared with calculations based on dispersion relations for virtual Compton scattering and with the MAID model
for pion electroproduction. There is an overall good agreement between experiment and theoretical calculations. The remaining
discrepancies may be ascribed to an imperfect parametrization of some γ
(*)
N→πN multipoles, mainly contributing to the non-resonant background. The beam-helicity asymmetry in both channels (γ and π
0) shows a good sensitivity to these multipoles and should allow future improvement in their parametrization. 相似文献
90.
为了在弹性波波导中实现缺陷态的调控,该文基于相位失配原理设计了一种周期性平板波导结构。以正弦边界弹性波导为例,通过连接具有不同相位的两段波导结构,形成了弹性板中不同程度的缺陷,并分析了其谱带特性和能量局域化特征。结果表明,禁带中存在两个不同模式的缺陷态,其以透射峰形式出现并随着相位的改变产生频移。与此同时,两个缺陷态在空间上对应的应力场和位移场分布也具有不同的模态特征。该文提出的复合弹性波导缺陷态调控方法,不仅为研究弹性波与结构之间的内在联系提供了关键的理论支持,也为实际弹性波探测器件的设计提供重要参考。 相似文献