Results 141 to 150 of about 51,215 (304)

A Bio‐Based Chiroptical Overcrowded Alkene From Flavanone: Photoreactivity and Theoretical Investigation

open access: yesChemistry – A European Journal, EarlyView.
A sustainable route to photoresponsive molecular systems is achieved using the bio‐based flavanone (‐)‐isolonchocarpin from Tephrosia vogelii. Through McMurry homocoupling and light‐driven 6‐π‐electrocyclization, an overcrowded alkene and a fluorescent O‐heterocyclic phenanthrene are synthesized.
Deryl H. Limawan   +8 more
wiley   +1 more source

Nonsmooth convex-concave saddle point problems with cardinality penalties [PDF]

open access: yes
In this paper, we focus on a class of convexly constrained nonsmooth convex-concave saddle point problems with cardinality penalties. Although such nonsmooth nonconvex-nonconcave and discontinuous min-max problems may not have a saddle point, we show ...
Chen, Xiaojun, Bian, Wei
core   +1 more source

Box–Behnken optimization and ANN‐ANFIS integrated modelling for transesterification using thermally activated basic oxygen furnace slag catalyst

open access: yesThe Canadian Journal of Chemical Engineering, EarlyView.
Abstract Global energy demand and environmental concerns have intensified the search for renewable and sustainable energy sources. This study thus, focuses on optimizing the transesterification process of waste cooking oil (WCO) using thermally activated basic oxygen furnace slag catalyst calcined at 850°C (BOF 850). The optimization and modelling were
Johra S. Ali, Hillary L. Rutto
wiley   +1 more source

Three-dimensional higher-order saddle-point-induced flatbands in Co-based kagome metals

open access: yesPhysical Review Research
The saddle point (Van Hove singularity) exhibits a divergent density of states in two-dimensional systems, leading to fascinating phenomena such as strong correlations and unconventional superconductivity, yet it is seldom observed in three-dimensional ...
Hengxin Tan   +4 more
doaj   +1 more source

A Geometric Characterization of Steady Laminar Flow

open access: yesCommunications on Pure and Applied Mathematics, EarlyView.
ABSTRACT We study the steady states of the Euler equations on the periodic channel or annulus. We show that if these flows are laminar (layered by closed non‐contractible streamlines which foliate the domain), then they must be either parallel or circular flows.
Theodore D. Drivas, Marc Nualart
wiley   +1 more source

Stochastic Gradient Descent in High Dimensions for Multi‐Spiked Tensor PCA

open access: yesCommunications on Pure and Applied Mathematics, EarlyView.
ABSTRACT We study the high‐dimensional dynamics of online stochastic gradient descent (SGD) for the multi‐spiked tensor model. This multi‐index model arises from the tensor principal component analysis (PCA) problem with multiple spikes, where the goal is to estimate the unknown signal vectors within the N$N$‐dimensional unit sphere through maximum ...
Gérard Ben Arous   +2 more
wiley   +1 more source

Exponentially‐constrained Gaussian mixture model for quantifying vertical development of water‐conducting fracture zones in lithologically stratified mining roofs

open access: yesDeep Underground Science and Engineering, EarlyView.
This study proposes an exponentially‐constrained Gaussian mixture model (EcGMM) to quantify vertical fracture heterogeneity in stratified roof strata. The model integrates a piecewise exponential decay term capturing global stress dissipation with Gaussian components representing localized fracture intensification at lithological interfaces.
Huiqing Yuan   +5 more
wiley   +1 more source

Solar Fuels Via Methane Valorization: Thermochemical Pathways, Unified Metrics, and Techno‐Economic Perspectives

open access: yesENERGY &ENVIRONMENTAL MATERIALS, EarlyView.
A first‐of‐its‐kind review benchmarks three solar methane valorization pathways with unified performance metrics for clean fuel production. Meeting global climate targets and sustainable energy demands requires carbon‐neutral fuels and innovative conversion pathways.
Muhammad Abdulmoez   +3 more
wiley   +1 more source

Low‐Dimensional Materials and Van Der Waals Heterostructures for Energy Application: A Comprehensive Review

open access: yesENERGY &ENVIRONMENTAL MATERIALS, EarlyView.
Low‐dimensional materials (0D, 1D, and 2D) exhibit unique electronic and physicochemical properties, enabling advanced nanoelectronic and optoelectronic devices. Mixed‐dimensional heterostructures combine these materials to enhance functionality.
Qaisar Alam   +3 more
wiley   +1 more source

Recent Advances in Prussian Blue Analogs as Capacitive Deionization Electrode Materials: Fundamentals, Structure–Performance Relationships, and Design Strategies

open access: yesENERGY &ENVIRONMENTAL MATERIALS, EarlyView.
This review systematically examines the fundamental ion‐storage mechanisms, the structural chemistry, and redox behavior of Prussian blue analogs as Faradaic electrodes in capacitive deionization, their intrinsic limitations and engineering optimization strategies, and the critical materials‐to‐device considerations required to advance PBA‐based CDI ...
Adekunle Adedapo Obisanya   +4 more
wiley   +1 more source

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