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Aimed at its elegance, the rigid-body-based procedure for geometric nonlinear analysis is extended to including the plastic-hinge concept for elasto-plastic analysis of framed structures. To this end, the rigid body test for initially stressed elements is first briefed, followed by derivation of the tangent stiffness of the 2D elasto-plastic beam element using the initial and full yield surfaces to consider gradual yielding of the cross-section. Of theoretical importance, the tangent and geometric stiffnesses are jointly tested by the rigid body rule for initially stressed elements. The above concepts are contained in the global and localstrategies, respectively, for tracing the load–deflection curves and for performing the trial-and-error iterations. The former can deal with the formation of multi plastic hinges, in addition to multi-critical points, whereas the latter is strongly rooted in the rigid body rule and thus is free of fictitious forces (source of slow convergence). The accuracy and efficiency of the solutions obtained are confirmed by comparison with the existing ones. In conclusion, the procedure proposed in its entity makes the elasto-plastic analysis simpler and faster. The more complicated the problem is, the greater the saving in computation time using the proposed procedure. Since only minimal mathematical operations are required, this procedure has the potential of being widely accepted by structural engineers in routine analysis. [ABSTRACT FROM AUTHOR]

The mechanical and thermodynamic properties of intermetallic compounds in the Ni-Ti system are studied by first-principles calculations. All phases show anisotropic elasticity in different crystallographic directions, in which Ni3Ti and NiTi2 are approaching the isotropy structure. The elastic moduli and Vicker's hardness of Ni-Ti system intermetallic compounds decrease in the following order: Ni3Ti B2_NiTi B19_NiTi NiTi2, and Ni3Ti shows the best mechanical properties. The intrinsic ductile nature of Ni-Ti compounds is confirmed by the obtained / ratio. The temperature dependence of linear thermal expansion coefficients (LTECs) of the compounds is estimated by the quasi-harmonic approximation (QHA) method. Ni3Ti shows the largest values among all Ni-Ti intermetallic compounds. At room temperature, the LTEC for Ni3Ti is 8.92 × 10 K, which falls in between the LTEC of zirconia toughened alumina (ZTA) (7.0-9.5 × 106 K) and iron matrix (9.2-16.9 × 106 K); i.e., the thermal matching of the ZTA/iron composite will be improved by introducing Ni3Ti intermetallic compound into their interface. Other thermodynamic properties such as sound velocity and Debye temperature are also obtained. [ABSTRACT FROM AUTHOR]

Molecular dynamics simulations have been performed to study the initial roll guided structural transition of graphene. The flat graphene is thermodynamic metastable and small disturbance can strike its balance and lead to fold. An initial roll at one end causes the graphene layer to transform into double-fold, multi-fold and scroll spontaneously, depending on the size of the initial roll. This unique phenomenon results from the combined action of the van der Waals interaction and the π-π stacking effect. The potential energy of the final structures decreases with the increase of compact level. This study provides crucial simulation input to help guide to designing the required graphene-based nanostructures. The flat graphene is thermodynamic metastable and an initial roll at one end can cause the graphene layer to transform into double-fold, multi-fold and scroll spontaneously, depending on the size of the initial roll. The suggested mechanism is that the vdW force among graphene layers induced by the initial roll provides sufficient attractive force to overcome the energy barrier, the π-π stacking effect between graphene layers cause the structure of graphene to transform spontaneously and stabilizes two parallel graphene walls to achieve the lowest energy AB stacking. [ABSTRACT FROM AUTHOR]

We present a global analysis of latest solar and reactor neutrino data in the three-neutrino mixing scheme by using both the simple grid scanning and the Markov Chain Monte Carlo (MCMC) sampling methods. Accuracy and efficiency of the two sampling methods are compared and advantages of the latter are discussed. The fitting results of three oscillation parameters θ12, θ13 and are provided with both old and new evaluations of the reactor antineutrino flux. Possible correlation between the fitting parameters is also discussed. [ABSTRACT FROM AUTHOR]

Molecular dynamics simulation is used to observe the traveling behavior of a water cluster released from the interior of single-walled carbon nanotube (SWCNT) to a graphite sheet. The simulation results reveal that there is a need for the water cluster overcoming the energy barrier of the binding energy between the water cluster and the SWCNT to escape from the tube. The water cluster undergoes a three-dimensional motion when released from the SWCNT, due to the effect of the thermal velocity. When encountering the graphite sheet in the forward direction, the x axis impact velocity has much effect on the delivery of the water cluster. The fact that the water cluster is bounced back reduces the possibility of being captured by the graphite sheet, resulting in a decrease in the delivery efficiency of the water cluster. The presence of the electric charges can help the graphite sheet to effectively trap the water cluster. These results have implications for the design and fabrication of novel drug delivery devices. [ABSTRACT FROM AUTHOR]

Molecular dynamics simulations are carried out to examine the heterogeneous solidification of aluminum solution seeded by foreign boron-nitride nanotubes (BNNTs). The final structure indicates noticeably that Al atoms are concentrated to form incredible hierarchical nanostructures composed of coaxial and equidistant cylindrical shells with the BNNTs as the heterogeneous core. The structures of so-formed Al cylinders show strict structural matching and strong structural relevance with BNNTs. Heterogeneous solidification occurred on BNNTs follows a spiral nucleating mechanism. Heredity effect of these hollow cylinders can be clearly observed during the heterogeneous nucleation. The uniform internal potential field around BNNTs is found to be responsible for the formation of the coaxial cylindrical Al shells. [ABSTRACT FROM AUTHOR]

We propose a seesaw scenario that possible corrections to the tribimaximal pattern of lepton mixing are due to the small phase splitting of the right-handed neutrino mass matrix. We show that the small deviations can be expressed analytically in terms of two splitting parameters (δ1 and δ2) in the leading order. The solar mixing angle θ12 favors a relatively smaller value compared to zero order value (35.3°), and the Dirac type CP phase δ chooses a nearly maximal one. The two Majorana type CP phases ρ and σ turn out to be a nearly linear dependence. Also a normal hierarchy neutrino mass spectrum is favored due to the stability of perturbation calculations. [ABSTRACT FROM AUTHOR]