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The Roper-Suffridge extension operator and classes of biholomorphic mappings Dedicated to Professor Sheng GONG on the occasion of his 75th birthday

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Science China Mathematics 2006年第11期49卷 1539-1552页

作者： GRAHAM Ian kohr gabriela Department of Mathematics University of Toronto TorontoOntario M5S 2E4Canada Faculty of Mathematics and Computer Science Babes-Bolyai University 1 M. Kogǎlniceanu Str. 400084 Cluj-NapocaRomania

In this paper we give a survey about the Roper-Suffridge extension operator and the developments in the theory of univalent mappings in several variables to which it has led. We begin with the basic geometric properties (most of which now have a number of different proofs)and discuss relations with the theory of Loewner chains and generalizations and modifications of the operator, some of which are very recent.

关键词： convex mapping, starlike mapping, Roper-Suffridge operator, growth theorem, distortion theorem, covering theorem, Loewner chain, parametric representation,extreme points, linear invariant family.

Homeomorphic extension of strongly spirallike mappings in C^n

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Science China Mathematics 2010年第1期53卷 87-100页

作者： CURT Paula kohr gabriela kohr Mirela Faculty of Economics and Business Administration Babes-Bolyai University 58-60 Teodor Mihali Str.400591 Cluj-NapocaRomania Faculty of Mathematics and Computer Science Babes-Bolyai University1 M.Kogaǎlniceanu Str.400084 Cluj-NapocaRomania

In this paper we consider a proper subclass nA of the full class of spirallike mappings on the Euclidean unit ball Bn in Cn with respect to a given linear operator A. We use the method of subordination chains to obtain an upper growth result for nA , and we obtain various examples of mappings in the same class of normalized biholomorphic mappings on the unit ball Bn in Cn . We also prove that the class nA is compact, while the full class of spirallike mappings with respect to a linear operator need not be compact in dimension n≥2, even when the operator is diagonal. This is one of the motivations for considering the class nA . Finally we prove that if f is a quasiregular strongly spirallike mapping on Bn such that ||[Df(z)]-1 Af(z)|| is uniformly bounded on Bn , then f extends to a homeomorphism of R2n onto itself. In addition, if A + A* = 2aI n for some a >0, this extension is also quasiconformal on R2n .

关键词： Biholomorphic mapping quasiregular mapping quasiconformal mapping spirallikeness strongly spirallikeness subordination subordination chain

Extreme points, support points and the Loewner variation in several complex variables

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Science China Mathematics 2012年第7期55卷 1353-1366页

作者： GRAHAM Ian HAMADA Hidetaka kohr gabriela kohr Mirela Department of Mathematics University of Toronto Toronto Ontario M5S 2E4 Canada Faculty of Engineering Kyushu Sangyo University 3-1 Matsukadai 2-Chome Higashi-ku Fukuoka 8138503 Japan Faculty of Mathematics and Computer Science Babe s-Bolyai University 1 M. Koga lniceanu Str. Cluj-Napoca 400084 Romania Faculty of Mathematics and Computer Science Babes-Bolyai University 1 M. Kogǎlniceanu Str. Cluj-Napoca 400084 Romania

In this paper we consider extreme points and support points for compact subclasses of normalized biholomorphic mappings of the Euclidean unit ball Bn in Cn. We consider the class So（Bn） of biholomorphic mappings on Bn which have parametric representation, i.e., they are the initial elements f（-, O） of a Loewner chain f（x,t） = etz ＋ ... such that {e-tf（.,t）}t≥o is a normal family on Bn. We show that if f（.,O） is an extreme point （respectively a support point） of So（Bn）, then e-t f（., t） is an extreme point of So（Bn） for t≥0 （respectively a support point of So（Bn） for t C [O, t0] and some to〉 0）. This is a generalization to the n-dimensional case of work due to Pell. Also, we prove analogous results for mappings which belong to So（Bn） and which are bounded in the norm by a fixed constant. We relate the study of this class to reachable sets in control theory generalizing work of Roth. Finally we consider extreme points and support points for biholomorphic mappings of Bn generated by using extension operators that preserve Loewner chains.

关键词： biholomorphic mapping Loewner chain parametric representation reachable set starlike map-ping

Exploring innovative synthetic solutions for advanced polymer-based electrochromic energy storage devices:Phenoxazine as a promising chromophore

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Journal of Energy Chemistry 2024年第4期91卷 433-452页

作者： Catalin-Paul Constantin Mihaela Balan-Porcarasu gabriela Lisa “Petru Poni”Institute of Macromolecular Chemistry Electroactive Polymers&Plasmochemistry Laboratory41A Grigore Ghica Voda AlleyIasi 700487Romania “Gh.Asachi”Technical University Iasi Faculty of Chemical EngineeringBd.Mangeron 71Iasi 700050Romania

The current investigation offers an innovative synthetic solution regarding electrochromic(EC)and energy storage applications by exploring phenoxazine(POZ)***,three POZ-based polymers(polyimide,polyazomethine,and polyamide)were synthesized to ascertain the superior *** polyamide exhibited remarkable attributes,including high redox stability during 500 repetitive CVs,optical contrast of 61.98%,rapid response times of 1.02 and 1.38 s for coloring and bleaching,EC efficiency of 280 cm^(2)C^(-1).and decays of the optical density and EC efficiency of only 12.18%and 6.23%after 1000 ***,the energy storage performance of polyamide PA was tested,for which the following parameters were obtained:74.7 F g^(-1)(CV,scan rate of 10 mV s^(-1))and 118 F g^(-1)(GCD,charging current of 0.1 A g^(-1)).Then,the polyamide was tested in EES devices,which yielded the following EC parameters:an optical contrast of 62.15%,response times of 9.24 and 5.01 s for coloring and bleaching,EC efficiency of 178 cm^(2)C^(-1),and moderate decays of 20.25%and 23.24%for the optical density and EC efficiency after 500 *** energy storage performance included a capacitance of 106 F g^(-1)(CV,scan rate of 0.1 mV s^(-1))and 9.23 F g^(-1)(GCD,charging current of 0.1 A g^(-1)),capacitance decay of 11.9%after500 cycles,and 1.7 V retention after 2 ***,two EES devices connected in series powered a 3 V LED for almost 30 s.

关键词： Polymers Phenoxazine Electrochromic Energy storage Electrochromi cenergy storage devices

Decentralized control in active distribution grids via supervised and reinforcement learning

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Energy and AI 2024年第2期16卷 137-149页

作者： Stavros Karagiannopoulos Petros Aristidou gabriela Hug Audun Botterud Laboratory for Information and Decision Systems(LIDS) Massachusetts Institute of TechnologyCambridgeUSA EEH-Power Systems Laboratory ETH Zurichhysikstrasse 38092 ZurichSwitzerland Department of Electrical Engineering Computer Engineering&InformaticsCyprus

While moving towards a low-carbon, sustainable electricity system, distribution networks are expected to host a large share of distributed generators, such as photovoltaic units and wind turbines. These inverter-based resources are intermittent, but also controllable, and are expected to amplify the role of distribution networks together with other distributed energy resources, such as storage systems and controllable loads. The available control methods for these resources are typically categorized based on the available communication network into centralized, distributed, and decentralized or local. Standard local schemes are typically inefficient, whereas centralized approaches show implementation and cost concerns. This paper focuses on optimized decentralized control of distributed generators via supervised and reinforcement learning. We present existing state-of-the-art decentralized control schemes based on supervised learning, propose a new reinforcement learning scheme based on deep deterministic policy gradient, and compare the behavior of both decentralized and centralized methods in terms of computational effort, scalability, privacy awareness, ability to consider constraints, and overall optimality. We evaluate the performance of the examined schemes on a benchmark European low voltage test system. The results show that both supervised learning and reinforcement learning schemes effectively mitigate the operational issues faced by the distribution network.

关键词： Supervised learning Reinforcement learning Deep deterministic policy gradient Decentralized control Active distribution systems

Use of graphs to assess well safety in drilling projects and during operations by identification of available barrier elements and consolidation of barrier envelopes

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PETROLEUM RESEARCH 2024年第3期9卷 418-431页

作者： Choueri Jr, Nelson Jaculli, Marcelo Anunciacao Leite, Amanda gabriela Aparecida Silva Mendes, Jose Ricardo Pelaquim Univ Estadual Campinas Campinas Brazil

Two independent barrier envelopes are the usual requirement used in most well operations to avoid catastrophic accidents. These are classified as primary- concerning preventing the occurrence of a kick, and secondary- concerning controlling the kick to avoid a blowout. Barrier envelopes consist of barrier elements, thus verifying the quality of these elements is fundamental. Barrier elements may be either redundant or mandatory, and these relationships are what constitute the barrier envelopes. In this work, we present a methodology to evaluate well safety by identifying existing barrier elements and barrier envelopes and mapping their relationships through the usage of graphs technique. This technique explicitly states the relationship between barriers and between them and envelopes. It enables a simpler visualization for well designers and allows the development of computer programs to control the safety and integrity of wells, both in the design phase and during drilling. 12 graphs are provided for a 4-phase well (conductor, surface, production, and drill-in), considering both the primary and secondary envelopes. Reasoning for constructing each graph is thoroughly provided. If these graphs are used, reliability values can then be assigned to each barrier element, which results in the reliability of entire barrier envelopes. This can be further extended to analyze the safety of each operation by applying the system to operational sequences and even comparing well designs.

关键词： Barrier elements Barrier envelopes Well design Well safety Graphs technique RISK ANALYSIS BAYESIAN NETWORKS OFFSHORE OIL RELIABILITY

Environmental changes affect picoplanktonic composition in Antarctic Peninsula ponds

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Advances in Polar Science 2024年第1期35卷 108-122页

作者： Micaela DÍAZ Leonardo LAGOMARSINO gabriela MATALONI Marianela BELTRÁN Marcela LIBERTELLI Paulina FERMANI Laboratorio de Ecología Acuática INTECH-UNSAM-CONICETChascomús 7130Argentina Facultad de Ciencias Naturales y de la Salud UNPSJBComodoro Rivadavia 9000Argentina Laboratorio de Biodiversidad Limnología y Biología de la Conservación3IA-UNSAM-CONICETBuenos Aires 1650Argentina Departamento de Biología de Predadores Tope Instituto Antártico ArgentinoBuenos Aires 1650Argentina Laboratorio de Microbiología Ambiental IBIOMAR/CESIMAR-CENPAT-CONICETPuerto Madryn 9120Argentina

Antarctic Peninsula is experiencing one of the largest global warming events *** water bodies generated by the melting of snow in summer are numerous,and they might act as sentinels of climate change due to their rapid response and ability to integrate catchment *** in climate can influence the structure of microbial communities which dominate these freshwaters ***,we characterize three ponds at Cierva Point(Antarctic Peninsula)by examining their physico-chemical and morphological characteristics and we explored how different factors modify the structure of the microbial *** studied the abundance and biomass of heterotrophic bacteria,picocyanobacteria and picoeukaryote algae during January and February of two consecutive summers(2017 and 2018).We found that ponds had different limnological characteristics,due to their location,geomorphological features and presence of the surrounding flora and ***-chemical parameters as well as microbial community differed between ponds,months and *** 2017,most ponds were oligo to mesotrophic *** larger accumulated rainfall(as a result of environmental changes on the Antarctic Peninsula)during 2018,particularly in February,causes nutrient runoff into water *** affects those ponds with the highest seabird circulation,such as gentoo penguin,increasing *** a result,picoplanktonic abundances were higher,and the community structure shifts to a largely heterotrophic bacteria dominated *** results suggest that these communities could act as sentinels to environmental changes,anticipating a future with mostly hypertrophic ponds.

关键词： microorganisms freshwater environments climate change Cierva Point

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Supplementation of vitamin E or a botanical extract as antioxidants to improve growth performance and health of growing pigs housed under thermoneutral or heat-stressed conditions

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Journal of Animal Science and Biotechnology 2024年第3期15卷 1101-1118页

作者： Ysenia V.Silva‑Guillen Consuelo Arellano Jeffrey Wiegert R.Dean Boyd gabriela E.Martinez Eric van Heugten Department of Animal Science North Carolina State UniversityRaleighNC 27695USA Department of Statistics North Carolina State UniversityRaleighNC 27695USA Department of Animal Science Texas A&M UniversityCollege StationTX 77843USA Animal Nutrition Research LLCAlvatonKY 42122USA.

Background Heat stress has severe negative consequences on performance and health of pigs,leading to significant economic *** objective of this study was to investigate the effects of supplemental vitamin E and a botanical extract in feed or drinking water on growth performance,intestinal health,and oxidative and immune status in grow-ing pigs housed under heat stress *** Duplicate experiments were conducted,each using 64 crossbred pigs with an initial body weight of 50.7±3.8 and 43.9±3.6 kg and age of 13-week and 12-week,***(n=128)were housed individually and assigned within weight blocks and sex to a 2×4 factorial arrangement consisting of 2 environments(thermo-neutral(21.2℃)or heat-stressed(30.9℃))and 4 supplementation treatments(control diet;control+100 IU/L of D-α-tocopherol in water;control+200 IU/kg of DL-α-tocopheryl-acetate in feed;or control+400 mg/kg of a botanical extract in feed).Results Heat stress for 28 d reduced(P≤0.001)final body weight,average daily gain,and average daily feed intake(-7.4 kg,-26.7%,and-25.4%,respectively)but no effects of supplementation were detected(P>0.05).Serum vitamin E increased(P<0.001)with vitamin E supplementation in water and in feed(1.64 vs.3.59 and 1.64 vs.3.24),but not for the botanical extract(1.64 vs.1.67 mg/kg)and was greater when supplemented in water ***(P=0.002).Liver vitamin E increased(P<0.001)with vitamin E supplementations in water(3.9 vs.31.8)and feed(3.9 vs.18.0),but not with the botanical extract(3.9 vs.4.9 mg/kg).Serum malondialdehyde was reduced with heat stress on d 2,but increased on d 28(interaction,P<0.001),and was greater(P<0.05)for antioxidant supplementation compared to *** proliferation was reduced(P=0.037)in the jejunum under heat stress,but increased in the ileum when vitamin E was supplemented in feed and water under heat stress(interaction,P=0.04).Tumor necrosis factor-αin jejunum and ileum mucosa decreased by heat stress(P<0.05)and was re

关键词： Botanical extract Growing pigs Heat stress Immune status Oxidative status Tocopherol Water

Overcoming Adversity:The Severe COVID-19 Illness Experience

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Sociology Study 2024年第4期14卷 171-182页

作者： gabriela Aissa Suciu Adriana Baban Babes-Bolyai University Cluj-NapocaRomania

This viral outbreak of the novel SARS-CoV-2 has profoundly disrupted lives globally and has placed unparalleled burdens on individual physical and psychological *** is imperative to comprehend the psychological journey of COVID-19 patients to provide them with effective *** study aimed to explore the psychological illness experience of severe COVID-19 survivors from the first symptoms,to hospitalization,recovery,and post-discharge ***-structured interviews were conducted from November 2022 to April 2023,with 30 Romanian former COVID-19 *** analysis of transcribed interviews identified four major themes:(1)a distant threat;(2)the tipping point;(3)the turning point;and(4)readjustment and *** participants faced denial or uncertainty early on,misattributing symptoms and delaying seeking *** as a last resort brought anxiety,isolation,and closer confrontations with mortality *** symptoms improved,and participants received supportive care from both healthcare professionals and family members,hope and optimism *** health improvements and feelings of safety,lingering anxiety ***-discharge adjustment involved managing lasting effects and selectively resuming *** some of the participants,reflection afterward prompted greater self-understanding,empathy and connection,and motivation for *** results have implications for healthcare practitioners,policymakers,and researchers.

关键词： illness experience COVID-19 survivors psychological impact emotional impact pandemic