Results 31 to 40 of about 146,876 (221)

Greedy Quasi-Newton Methods with Explicit Superlinear Convergence

open access: yesSIAM Journal on Optimization, 2021
In this paper, we study greedy variants of quasi-Newton methods. They are based on the updating formulas from a certain subclass of the Broyden family. In particular, this subclass includes the well-known DFP, BFGS and SR1 updates. However, in contrast to the classical quasi-Newton methods, which use the difference of successive iterates for updating ...
Rodomanov, Anton, Nesterov, Yurii
openaire   +3 more sources

Optimization of 3D‐Printed Structured Packings—Current State and Future Developments

open access: yesChemie Ingenieur Technik, EarlyView.
This paper gives an overview about structured packing development for distillation, surveying heuristic development cycles, computational fluid dynamics simulations, and additive manufacturing techniques. The emerging application of shape optimization to improve packings is emphasized, and its benefits, impact, and limitations are discussed.
Dennis Stucke   +3 more
wiley   +1 more source

Experimental methods in chemical engineering: Atomic absorption spectrometry—AAS

open access: yesThe Canadian Journal of Chemical Engineering, EarlyView.
Abstract Elements absorb electromagnetic radiation (light) of a specific wavelength in proportion to the number of atoms in its path. As the atoms absorb this light energy, electrons rise from the ground state to an excited state. In atomic absorption spectrometry (AAS), high temperatures produce clouds of atoms from the sample (atomization) and ...
Emily Cintia Tossi de A. Costa   +4 more
wiley   +1 more source

Stabilized material point methods for coupled large deformation and fluid flow in porous materials

open access: yes, 2019
The material point method (MPM) has been increasingly used for the simulation of large deformation processes in fluid-infiltrated porous materials. For undrained poromechanical problems, however, standard MPMs are numerically unstable because they use ...
Choo, Jinhyun, Zhao, Yidong
core   +2 more sources

Ultrafast Transitions in X‐Ray Irradiated Solids

open access: yesContributions to Plasma Physics, EarlyView.
ABSTRACT In this review, we present current developments on modeling ultrafast transitions in solids triggered by intense, atto‐ to femtosecond pulses from X‐ray free electron lasers. This specific irradiation regime requires dedicated simulation tools based on theoretical and computational methods, involving the elements of classical and quantum ...
Sebastião Antunes   +3 more
wiley   +1 more source

IMRO: a proximal quasi-Newton method for solving $l_1$-regularized least square problem

open access: yes, 2017
We present a proximal quasi-Newton method in which the approximation of the Hessian has the special format of "identity minus rank one" (IMRO) in each iteration. The proposed structure enables us to effectively recover the proximal point.
Karimi, Sahar, Vavasis, Stephen
core   +1 more source

Creep properties and constitutive model of diabase in deep water conveyance tunnels

open access: yesDeep Underground Science and Engineering, EarlyView.
The axial and lateral creep characteristics of diabase were analyzed based on compression creep tests. The nonlinear viscoelastic‐plastic model capable of describing the whole creep process was established based on the fractional derivative and damage theories.
Zhigang Tao   +5 more
wiley   +1 more source

Review and prospects of shear test of bolted rock joints

open access: yesDeep Underground Science and Engineering, EarlyView.
The laboratory shear test equipment, test method, and numerical simulation of bolted rock joints were summarized. The shortcomings and limitations of the current research were analyzed, and the research prospects were proposed. Abstract Rock bolting is a critical approach in geotechnical engineering for supporting weak rocks.
Shulin Ren   +4 more
wiley   +1 more source

Low‐Ru‐Content CuCoRu Aerogel for Boosted Electrocatalytic Nitrate Reduction to Ammonia

open access: yesEcoEnergy, EarlyView.
Low‐Ru‐content Cu5Co5Ru aerogel with enhanced hydrogenation ability and 3D robust aerogel skeletons enables high‐efficiency and long‐term electrocatalytic nitrate reduction to ammonia at low overpotential, achieving an exceptional ammonia yield rate of 2.7 ± 0.1 mmol cm−2 h−1 and a high Faradaic efficiency of ∼97% at −0.1 V versus RHE as well as an ...
Jinjie Tan   +11 more
wiley   +1 more source

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