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APPROXIMATING THE STATIONARY BELLMAN EQUATION BY HIERARCHICAL TENSOR PRODUCTS

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Journal of Computational Mathematics 2024年第3期42卷 638-661页

作者： Mathias Oster Leon Sallandt Reinhold schneider Technische Universität Berlin Strasse des 17.Juni 13510623 BerlinGermany

We treat infinite horizon optimal control problems by solving the associated stationary Bellman equation numerically to compute the value function and an optimal feedback *** dynamical systems under consideration are spatial discretizations of non linear parabolic partial differential equations(PDE),which means that the Bellman equation suffers from the curse of *** non linearity is handled by the Policy Iteration algorithm,where the problem is reduced to a sequence of linear equations,which remain the computational bottleneck due to their high *** reformulate the linearized Bellman equations via the Koopman operator into an operator equation,that is solved using a minimal residual *** the Koopman operator we identify a preconditioner for operator equation,which deems essential in our numerical *** overcome computational infeasability we use low rank hierarchical tensor product approximation/tree-based tensor formats,in particular tensor trains(TT tensors)and multi-polynomials,together with high-dimensional quadrature,*** controlling a destabilized version of viscous Burgers and a diffusion equation with unstable reaction term numerical evidence is given.

关键词： Feedback control Dynamic programming Hamilton-Jacobi-Bellman Tensor product approximation Variational Monte-Carlo

Modeling displacement flow inside a full-length casing string for well cementing

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Petroleum Research 2024年第1期9卷 1-16页

作者： Hu Dai Ali Eslami Jason schneider Gefei Liu Fred Schwering Pegasus Vertex Inc.USA Laval University Canada Sanjel Energy Services Canada Athabasca Oil Corporation Canada

While computer modeling of annular displacement efficiency is widely applied in cementing engineering,modeling the displacement flow inside a casing or drill string for cementing operations has received less *** predicting displacement efficiency inside a full-length pipe is desired by cementing engineers,the attempt of developing a model with both efficiency and accuracy faces *** to computer simulators for this purpose is *** with annular flow,the displacement flow inside pipe,although within a simpler geometry and without eccentricity effect,is not simpler in physics,modelling strategy and predictability,because a variety of flow patterns and flow instabilities can develop to create complicated fluid *** this paper,we present an integrated numerical model developed to simulate displacement flows inside a full-length pipe,which connects an existing annulus model to enable complete displacement simulations of cementing *** model uses three-dimensional grid to solve fluid concentrations with degrees of mixing,and incorporates flow instability detection and flow regime *** in cementing,the model accounts for effects of pumping rate,well inclination,pipe rotation,fluid densities,rheological parameters and *** computationally efficient model does not rely on high-resolution mesh as often required by conventional Computational Fluid Dynamics models,thus it is suitable to be implemented in a cementing software for daily use by well cementing *** methodology of the model is discussed in detail in this *** validate the model,we examine simulation results against experimental results obtained in our laboratory tests and CFD simulations;acceptable agreement is found under different testing *** also presented two case studies of real cementing jobs with cement evaluation logs compared to simulation results,showing that the model can predict consistent displacement efficie

关键词： Inside pipe displacement Displacement efficiency Numerical model Primary cementing Displacement flow

Two-photon emission from a superlattice-based superconducting light-emitting structure

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Light(Science & Applications) 2024年第7期13卷 1331-1340页

作者： Shlomi Bouscher Dmitry Panna Ronen Jacovi Fauzia Jabeen Christian schneider Sven Höfling Alex Hayat Department of Electrical Engineering TechnionHaifa 32000Israel. Technische Physik Universität WürzburgAm HublandD-97074 WürzburgGermany. Institute of Physics Carl von Ossietzky Universität OldenburgD-26111 OldenburgGermany

Superconductor-semiconductor hybrid devices can bridge the gap between solid-state-based and photonics-based quantum systems,enabling new hybrid computing schemes,offering increased scalability and *** example for a hybrid device is the superconducting light-emitting diode(SLED).SLEDs have been theoretically shown to emit polarization-entangled photon pairs by utilizing radiative recombination of Cooper ***,the twophoton nature of the emission has not been shown experimentally *** demonstrate two-photon emission in a GaAs/AlGaAs *** electroluminescence spectra reveal unique two-photon superconducting features below the critical temperature(Tc),while temperature-dependent photon-pair correlation experiments(g(2)(τ,T))demonstrate temperature-dependent time coincidences below Tc between photons emitted from the *** results pave the way for compact and efficient superconducting quantum light sources and open new directions in light-matter interaction studies.

关键词： photon quantum utilizing

Spirooxindoles:Recent report of green synthesis approach

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Green Synthesis and Catalysis 2024年第1期5卷 1-13页

作者： Agus Rimus Liandi antonius Herry Cahyana Diva Naufal Alfariza Rahma Nuraini Renita Wulan Sari Tio Putra Wendari Department of Chemistry Faculty of Science and TechnologyUniversitas Islam Negeri Syarif Hidayatullah JakartaTangerang Selatan 15412Indonesia Department of Chemistry Faculty of Mathematics and Natural SciencesUniversitas IndonesiaDepok 16424Indonesia Department of Chemistry Faculty of Mathematics and Natural SciencesUniversitas AndalasPadang 25163Indonesia

Spirooxindole is a compound with a unique framework and broad bioactivities in *** this study,we have reviewed various approaches or methods in synthesizing spirooxindole derivatives focused on green *** of spirooxindoles is mainly carried out through multicomponent reactions combined with various green approaches such as the use of heterogeneous catalysts(nano-sized,magnetic,metal-complex,and metal-organic framework catalysts),deep eutectic solvent,solvent-free reactions,catalyst-free reactions,as well as the use of ultrasonic and microwaves *** green method is carried out in addition to obtaining high yields,it also offers reductions in the use of hazardous chemicals,energy use,purification processes,and waste *** a result,green synthesis methods in the synthesis of spirooxindole derivatives are more environmentally friendly.

关键词： Spirooxindoles Green synthesis Catalysis Nanoparticle Ultrasonic irradiation

Femoral Access with Ultrasound-Guided Puncture and Z-Stitch Hemostasis for Adults with Congenital Heart Diseases Undergoing Electrophysiological Procedures

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Congenital Heart Disease 2024年第1期19卷 85-92页

作者： Fu Guan Matthias Gass Florian Berger Heiko schneider Firat Duru Thomas Wolber Arrhythmia and Electrophysiology Division Department of CardiologyUniversity Heart Center ZurichZurichSwitzerland Children’s Research Center Zurich University Children’s HospitalZurichSwitzerland Center for Integrative Human Physiology University of ZurichZurichSwitzerland

Aims:Although the application of ultrasound-guided vascular puncture and Z-stitch hemostasis to manage femoral access has been widely utilized,there is limited data on this combined application in adult congenital heart disease(ACHD)patients undergoing electrophysiological(EP)*** sought to evaluate the safety and efﬁcacy of ultrasound-guided puncture and postprocedural Z-stitch hemostasis for ACHD patients under-going EP *** and Results:The population of ACHD patients undergoing transfemoral EP pro-cedures at the University of Zurich Heart Center between January 2019 and December 2022 was observed and *** the study period,femoral access(left/right,arterial/venous)was performed under real-time ultrasound *** the end of the procedure,a single Z-stitch was performed at the puncture *** eval-uated the incidence of in-hospital complications associated with femoral access puncture in this *** 101 patients who had a total of 147 previous ipsilateral vascular punctures(mean 1.5 per person),100 patients underwent successful femoral vascular access for EP *** median age of the patients was 47±15 years and 34(34%)were male.Z-stitches were performed after the procedure in 100 patients with 303 femoral vascular accesses(mean 3 punctures per person).No patient developed vascular puncture relevant inguinal hematoma,pseudo aneurysm,arteriovenousﬁstula,venous or arterial ***:In ACHD patients undergoing EP procedures,optimal femoral access management can be achieved with ultra-sound-guided puncture and postprocedural Z-stitch hemostasis.

关键词： Congenital heart disease cardiac electrophysiology cardiac catheterization femoral access hemostasis

Emerging and multifaceted potential contributions of polyphenols in the management of type 2 diabetes mellitus

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World Journal of Diabetes 2024年第2期15卷 154-169页

作者： Ileana González Cristian Lindner Ivan schneider Erik Diaz Miguel Angel Morales Armando Rojas Biomedical Research Laboratories Faculty of MedicineCatholic University of MauleTalca 34600000Chile Department of Radiology Faculty of MedicineUniversity of ConcepciónConcepción 4030000Chile Centre of Primary Attention South Metropolitan Health ServiceSantiago 3830000Chile Faculty of Medicine Catholic University of MauleTalca 3460000Chile Molecular and Clinical Pharmacology Program Institute of Biomedical SciencesUniversity of ChileSantiago 8320000Chile

Type 2 diabetes mellitus(T2DM)is recognized as a serious public health concern with a considerable impact on human life,long-term health expenditures,and substantial health *** this context,the use of dietary polyphenols to prevent and manage T2DM is widely *** dietary compounds exert their beneficial effects through several actions,including the protection of pancreatic islet β-cell,the antioxidant capacities of these molecules,their effects on insulin secretion and actions,the regulation of intestinal microbiota,and their contribution to ameliorate diabetic complications,particularly those of vascular *** the present review,we intend to highlight these multifaceted actions and the molecular mechanisms by which these plant-derived secondary metabolites exert their beneficial effects on type 2 diabetes patients.

关键词： Polyphenols Antioxidants Oxidative stress Type 2 diabetes mellitus Health benefits

Cretaceous Large Igneous Provinces (LIPs) Affect Sedimentary Processing: Jordan, Arabian Plate;NW Germany, Central Europe

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Open Journal of Geology 2024年第6期14卷 671-704页

作者： Werner schneider Elias Salameh (Retired) Department of Geology Faculty of Science Braunschweig Technical University Braunschweig Germany Department of Geology Faculty of Science University of Jordan Amman Jordan

Both the NE Gondwana Platform (Jordan) and the Carpathian/NW Europe Seaway towards the N Atlantic expose comparable sequence analytical patterns as i.e. the Maximum Flooding Surface (MSF), relating to the Arabian Shelf, throughout one of the warmest Phanerozoic Epochs. Supervolcanic Large Igneous Provinces (LIPs), (explosive island arc andesitic volcanism), Mid-Oceanic Rift Basalts (MORB), (S/N Atlantic, Arctic) and kimberlitic volcanism (W Gondwana) provided striking conditions for an immense influence (tuff, degassing, T) on the sedimentary processing throughout the Cretaceous, mainly verified by K-montmorillonite , dozens of tuff beds (predominantly in NW Germany), zeolite, cristobalite, extremely high chert occurrences as well as the reconfirming of the global anoxic event around the Cenomanian/Turonian b. (94 Ma) by a positive ∂13C-maximum (~0.5%). Thus the lithofacies spectrum (carbonate rocks, chalk, chert, porcellanite, shale) was affected by pH, Eh, T, photosynthesis, and greenhouse gases—change during varying positive/negative climate forcing. While acid sturzrain events caused the transformation of arkosic/subarkosic sediments of the hinterlands to quartz arenite cycles deposited on the Jordanian Platform during early Cretaceous, the other patterns mentioned, led to a rapid change of lithofacies through Late Cretaceous. The southward directed Neotethys transgression can be reconstructed during the Early Cretaceous by glauconite-aged tidalites that give hint on transpressional tectonics during the Upper Cenomanian east of the Dead Sea. The Cretaceous/Paleogene (K-Pg) transitional zone evidences a zone of several cumulative events (island arc-volcanism) and the Chicxulub impact, indicated by at least two extinctions phases. The southward obduction of the Palmyrides, Syria and related transtensional/transpressional strike slip tectonics (partially pull-apart structures) left a fast facies change on the Jordanian Platform.

关键词： Degassing Explosive Tuff Acid Rain Climate Forcing Photosynthesis Mineral Trans/Neoformation Lithofacies Modified Synsedimentary Tectonics

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At the Dog Park

小学生时代（大嘴英语） 2024年第7期 50-53页

作者： Christine schneider(图) 不详

Antioxidant Activity and Phytochemical Screening in Acacia rigidula Benth. Leaves

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Advances in Bioscience and Biotechnology 2024年第1期15卷 15-38页

作者： Aneth Ochoa-Negrete Rene Rangel Marcus antonius Ynalvez Ruby A. Ynalvez Department of Biology and Chemistry Texas A&M International University Laredo TX USA Department of Social Sciences Texas A&M International University Laredo TX USA

This study aimed to compare the total phenolic content (TPC) and antioxidant activities of A. rigidula extracts. It also aimed to identify phenolic acids present in the extracts. The 2,2-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP), and ferric thiocyanate lipid peroxidation antioxidant assays were performed. High performance liquid chromatography was used to identify phenolic acids. There was no solvent effect on TPC nor on scavenging activities, and inhibition of lipid peroxidation (p > 0.05) among solvent extracts. On the other hand, 1:1:3 water: acetone: methanol extract (10.22 mg GAE/g sample) had significantly higher reducing potential than 50% ethanol extract (EE) (9.259 mg GAE/g sample) (p 0.05). Phenolic fraction designated as fraction 4 had the highest antioxidant activity (p < 0.05) with 69.49% ABTS scavenging activity and FRAP reducing potential, 22.26 mg of GAE/g sample. DPPH scavenging activities of fractions 4 (55.59%) and 5 (55.64%) were significantly higher than the other fractions (p A. rigidula extracts contain gallic, caffeic, vanillic, p-coumaric, salicylic acids and vanillin.

关键词： Acacia Plant Extract Antioxidant Activity Total Phenolic Acid HPLC Gallic Acid