China
Africa
Explore chapters and articles related to this topic
ab initio Transport Calculations for Single Molecules
Published in Sergey Edward Lyshevski, Nano and Molecular Electronics Handbook, 2018
Time-dependent DFT is a well-established generalization of (ground state) density functional theory and has been introduced by Runge and Gross [21] and expanded on by van Leeuwen [22]. RG-Theorem: For any interacting fermion system, there is a unique dual system of non-interacting fermionic quasiparticles with the following property: the time-dependent density of original and dual particles is identical for any driving field Vex(t); the time evolution of dual (“Kohn-Sham” or KS) fermions is governed by a Schrödinger-type equation decorated with a Hartree term and an exchange correlation potential VXC [n], which can be expressed as a functional of the time-dependent particle density and its history, n(x, t). In the general case, Vxc[n] depends on the full many-body state at the initial time t = 0.
The Laplace Equation
Published in Christian Constanda, Direct and Indirect Boundary Integral Equation Methods, 2020
1.10. Definition. By a dual system (X, Y) we understand a pair of normed spaces X and Y together with a non-degenerate bilinear form ⋅,⋅:X×Y→ℂ.
Proposed structural system for mixed hollow flat slab
Published in Water Science, 2022
The objective of the present study is to introduce a proposal for a combined flooring slab construction system that is a mix of two different systems. This proposed system consists of flat slab system replacing its field strips by two-way hollow block slabs, aimed to achieve a dual system with more advantages. The effect of applying the proposed system on the required quantities of concrete and steel reinforcement has been studied under the effect of static and dynamic loadings.
Assessment of the Seismic Performance and the Base Shear Contribution Ratios of the RC Wall-frame Dual System Considering Soil–Structure Interaction
Published in Journal of Earthquake Engineering, 2022
Mahmoud Katrangi, Mohammad Mahdi Memarpour, Mansoor Yakhchalian
The differences between foundation input motions (FIM) and free-field ground motions (FFM) are attributed to the kinematic interaction effects. Kinematic interaction results from the presence of stiff foundation elements on or inside the soil, which causes input motions at the foundation level to deviate from free-field motions. Basically, the main causes of kinematic interaction are the base-slab averaging and the embedment effect (NIST GCR 12-917-21 2012). Base-slab averaging is a result of inclined or incoherent incident wave fields that reduce the translational base-slab motions relative to the FFM. This reduction of the translational base-slab motions tends to become more significant with a decrease in the period and an increase in the effective size of the foundation relative to the seismic wavelengths at higher frequencies. The kinematic interaction effect is more significant for the foundations that are located at a lower elevation than the surrounding ground, especially when structures have a basement (Kim and Stewart 2003). In the study conducted by Petridis and Pitilakis (2020), the ratio between FFM and FIM was defined by a transfer function in the frequency domain and the kinematic interaction effects were considered by following NIST GCR 12-917-21 (2012) for every single FFM. However, in this study given that no basement was considered in all the models, by assuming vertically propagating shear waves on the surface foundation (i.e., neglecting kinematic interaction) the differences between the FIM and FFM were neglected. Hence, the ground motion was applied at the far ends of the horizontal springs PySimple1 and TzSimple1 by using the imposedMotion command in the OpenSees program. This assumption is similar to that made by Behnamfar and Banizadeh (2016). Furthermore, the mass of the foundation was modeled and concentrated at the columns nodes at the base level. It is noteworthy that neglecting the base-slab averaging for high-rise buildings increases higher modes responses, whereas it does not affect first mode response considerably. Investigating the kinematic interaction effects on base shear contribution ratios of the RC wall-frame dual system is an open field for future studies.