Results 61 to 70 of about 701,026 (330)

Exact quantum states of a general time-dependent quadratic system from classical action

open access: yes, 1998
A generalization of driven harmonic oscillator with time-dependent mass and frequency, by adding total time-derivative terms to the Lagrangian, is considered.
A. Mostafazadeh   +25 more
core   +1 more source

A Simulative Approach for the Prediction of Mesoscale Residual Stress Fields in Solution‐Strengthened Ferritic Ductile Iron

open access: yesAdvanced Engineering Materials, EarlyView.
This study presents a 3D representative volume element‐based simulation approach to predict mesoscopic residual stress and strain fields in silicon solid solution‐strengthened ductile cast iron. By modeling phase transformation kinetics with an enhanced Johnson–Mehl–Avrami–Kolmogorov model, the effects of varying cooling rates on residual stresses are ...
Lutz Horbach   +6 more
wiley   +1 more source

Removing Homocoupling Defects in Alkoxy/Alkyl‐PBTTT Enhances Polymer:Fullerene Co‐Crystal Formation and Stability

open access: yesAdvanced Functional Materials, EarlyView.
PBTTT‐OR‐R, a C14‐alkoxy/alkyl‐PBTTT polymer derivative, is of substantial interest for optoelectronics due to its specific fullerene intercalation behavior and enhanced charge‐transfer absorption. Comparing this polymer with (S) and without (O) homocoupling defects reveals that PBTTT‐OR‐R(O) forms stable co‐crystals with PC61BM, while PBTTT‐OR‐R(S ...
Zhen Liu   +14 more
wiley   +1 more source

Geodesic deviation in pp-wave spacetimes of quadratic curvature gravity

open access: yes, 2003
We write the equation of geodesic deviations in the spacetime of $pp$-waves in terms of the Newman-Penrose scalars and apply it to study gravitational waves in quadratic curvature gravity.
A. Accioly   +17 more
core   +1 more source

Electricity Generation From Ambient Water Evaporation in the Absence of Sunlight via PVA‐Based Porous Hydrogels

open access: yesAdvanced Functional Materials, EarlyView.
In this article, a water‐evaporation driven energy harvester is devised that works even in the absence of sunlight. This is achieved by combining PVA hydrogel with thermoelectrics (TEG) to directly capture energy from water evaporation. Under mild conditions (RH 40%, T of 26 °C, and 2.8 m s−1 wind), 1.71 mW (1.02 W m−2) power can be generated, >3 fold ...
Zichen Gong, Ady Suwardi, Jing Cao
wiley   +1 more source

Light‐Controlled Reversible Coassembly of Hybrid Functional Nanostructures

open access: yesAdvanced Functional Materials, EarlyView.
Light‐responsive hybrid nanostructures are formed by coassembling azobenzene‐ and PAH‐functionalized nanoparticles through reversible an tunable π interactions. The system enables tunable coupling between distinct components such as gold and magnetite or carbon nanotubes, producing switchable optical and magnetic properties under light and magnetic ...
Michal Sawczyk   +5 more
wiley   +1 more source

Classification of Lie point symmetries for quadratic Li$\acute{\textbf{e}}$nard type equation $\ddot{x}+f(x)\dot{x}^2+g(x)=0$

open access: yes, 2013
In this paper we carry out a complete classification of the Lie point symmetry groups associated with the quadratic Li$\acute{e}$nard type equation, $\ddot {x} + f(x){\dot {x}}^{2} + g(x)= 0$, where $f(x)$ and $g(x)$ are arbitrary functions of $x$.
Lakshmanan, M.   +3 more
core   +1 more source

Prospects of Electric Field Control in Perpendicular Magnetic Tunnel Junctions and Emerging 2D Spintronics for Ultralow Energy Memory and Logic Devices

open access: yesAdvanced Functional Materials, EarlyView.
Electric control of magnetic tunnel junctions offers a path to drastically reduce the energy requirements of the device. Electric field control of magnetization can be realized in a multitude of ways. These mechanisms can be integrated into existing spintronic devices to further reduce the operational energy.
Will Echtenkamp   +7 more
wiley   +1 more source

The system of mixed type additive-quadratic equations and approximations

open access: yesJournal of Inequalities and Applications
In this article, we study the structure of a multiple variable mapping. Indeed, we reduce the system of several mixed additive-quadratic equations defining a multivariable mapping to obtain a single functional equation, say, the multimixed additive ...
Abasalt Bodaghi   +2 more
doaj   +1 more source

The arithmetic of arithmetic Coxeter groups

open access: yes, 2018
In the 1990s, J.H. Conway published a combinatorial-geometric method for analyzing integer-valued binary quadratic forms (BQFs). Using a visualization he named the "topograph," Conway revisited the reduction of BQFs and the solution of quadratic ...
Milea, Suzana   +2 more
core   +1 more source

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