检索结果-南通市图书馆

Gorenstein injective sheaves

在线全文

学校读者我要写书评

暂无评论

Frontiers of Mathematics in China 2017年第1期12卷 87-95页

作者： sergio ESTRADA Alina IACOB Departamento de Matem~ticas Universidad de Murcia Murcia 30100 Spain Department of Mathematical Sciences Georgia Southern University Statesboro GA 3O460 USA

We define Gorenstein injective quasi-coherent sheaves, and prove that the notion is local in case the scheme is Gorenstein. We also give a new characterization of a Gorenstein scheme in terms of the total acyclicity o... 详细信息

关键词： Gorenstein injective Noetherian scheme

Reactive pathways toward parasitic release of singlet oxygen in metal-air batteries

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

npj Computational Materials 2021年第1期7卷 1135-1142页

作者： Adriano Pierini sergio Brutti Enrico Bodo Department of Chemistry University of Rome“La Sapienza”RomeItaly GISEL—Centro di Riferimento Nazionale per i Sistemi di Accumulo Elettrochimico di Energia FirenzeItaly

The superoxide disproportionation reaction is a key step in the chemistry of aprotic metal oxygen batteries that controls the peroxide formation upon discharge and opens the way for singlet oxygen *** we clarify the energy landscape of the disproportionation of superoxide in aprotic media catalyzed by group 1A *** analysis is based on ab initio multireference computational methods and unveils the competition between the expected reactive path leading to peroxide and an unexpected reaction channel that involves the reduction of the alkaline *** channels lead to the release of triplet and singlet O_(2).The existence of this reduction channel not only facilitates singlet oxygen release but leads to a reactive neutral solvated species that can onset parasitic chemistries due to their well-known reducing ***,we show that the application of moderate overpotentials makes both these channels accessible in aprotic batteries.

关键词： properties release singlet

Superattracting cycles for some Newton type iterative methods

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Mathematics 2011年第3期54卷 539-544页

作者： AMAT sergio BUSQUIER Sonia NAVARRO Emilie PLAZA sergio Departamento de Matemtica Aplicada y Estadistica Universidad Politécnica de Cartagena Ecole Généraliste d'Ingénieurs de Marseille (EGIM) Departamento de Matemticas Facultad de Ciencias Universidad de Santiago de Chile

The paper is devoted to the analysis of certain dynamical properties of a family of iterative Newton type methods used to find roots of non-linear equations. We present a procedure for constructing polynomials in such a way that superattracting cycles of any prescribed length occur when these iterative methods are applied. This paper completes the study begun in Amat, Bermúclez, Busquier, et al., (2009).

关键词： iterative methods (super)attracting cycles dynamics

Performance Improvement of Artificial Neural Network Model in Short-term Forecasting of Wind Farm Power Output

在线全文

学校读者我要写书评

暂无评论

Journal of Modern Power Systems and Clean Energy 2020年第3期8卷 484-490页

作者： sergio Velázquez Medina Ulises Portero Ajenjo Department of Electronics and Automatics Engineering Universidad de Las Palmas de Gran CanariaCampus de Tafira s/n35017 Las Palmas de Gran CanariaCanary IslandsSpain School of Industrial and Civil Engineering University of Las Palmas de Gran CanariaCampus de Tafira s/n35017 Las Palmas de Gran CanariaCanary IslandsSpain

Due to the low dispatchability of wind power,the massive integration of this energy source in power systems requires short-term and very short-term wind power output forecasting models to be as efficient and stable as possible.A study is conducted in the present paper of potential improvements to the performance of artificial neural network(ANN)models in terms of efficiency and ***,current ANN models have been developed by considering exclusively the meteorological information of the wind farm reference station,in addition to selecting a fixed number of time periods prior to the *** this respect,new ANN models are proposed in this paper,which are developed by:varying the number of prior 1-h periods(periods prior to the forecasting hour)chosen for the input layer parameters;and/or incorporating in the input layer data from a second weather station in addition to the wind farm reference *** has been found that the model performance is always improved when data from a second weather station are *** mean absolute relative error(MARE)of the new models is reduced by up to 7.5%.Furthermore,the longer the forecasting horizon,the greater the degree of improvement.

关键词： Artificial neural networks(ANN) wind power forecasting model performance wind power output

Quality of public space and sustainable development goals:analysis of nine urban projects in Spanish cities

在线全文

学校读者我要写书评

暂无评论

Frontiers of Architectural Research 2023年第3期12卷 477-495页

作者： Raimundo BambóNaya Pablo de la Cal Nicolás Carmen Díez Medina Isabel Ezquerra sergio garcía-Pérez Javier Monclús Departamento de Arquitectura Universidad de ZaragozaZaragoza 50018Spain Instituto Universitario de Investigación en Patrimonio y Humanidades(IPH) Universidad de ZaragozaZaragoza 50018Spain

The starting point of this research is the urban model promoted by the United Nations through the Sustainable Development Goals(SDGs).The importance of public spaces is especially highlighted in Goal 11.7:“provide universal access to safe,inclusive,and accessible,green,and public spaces.”The quality of public spaces can be properly assessed by reconsidering the quality indicators and investigating their development potential,which is the main focus of our *** study is based on a theoretical and methodological reflection on the quality of public space,considering the contributions of some contemporary urban traditions and a few recent *** this perspective,a variety of public space projects developed in the European sphere have been selected and *** quality parameters identified in this initial analysis were then applied to the analysis of nine representative case studies in three Spanish cities(Madrid,Barcelona,and Zaragoza).The main goal is to propose a methodology that helps to evaluate the quality of those public spaces and determine its relationship with the safety,accessibility,and inclusiveness conditions they offer.

关键词： Safety Inclusiveness Accessibility Design strategy Urban project

Exploring the adjustment to parasite pressure hypothesis: differences in uropygial gland volume and haemosporidian infection in palearctic and neotropical birds

在线全文

学校读者我要写书评

暂无评论

Current Zoology 2021年第2期67卷 147-156页

作者： sergio MAGALLANES Anders Pape MøLLER Charlene LUJÁN-VEGA Esteban FONG Daniel VECCO Wendy FLORES-SAAVEDRA Luz garcÍA-LONGORIAA Florentino DE LOPE JoséA.IANNACONE Alfonso MARZAL Department of Anatomy Cellular Biology and ZoologyUniversity of ExtremaduraAvda.de Elvas S/NBadajoz ES-06006Spain Ecologie Systématique Evolution UniversitéParis-SudOrsay 91400France Key Laboratory for Biodiversity Science and Ecological Engineering of Ministry of Education College of Life SciencesBeiing Normal UniversityBeiing 100875China Pharmacology and Toxicology Graduate Group University of CaliforniaDavisDavisCA 95616USA EverGreen Institute-San Rafael Distrito de IndianaLoreto 16200Perú Centro Urku de Estudios Amazónicos Tarapoto 22202Perú Universidad Nacional Agraria La Molina Lima 15024Perú Molecular Ecology and Evolution Lab Department of BiologyLund UniversityLund 22100Sweden Laboratorio de Ingenieria Ambiental Universidad Cientifica del Sur-Villa el SalvadorLima 15067Perú Laboratorio de Invertebrados Universidad Ricardo PalmaSantiago de Surco 15039Perú

Parasites are globally widespread pathogenic organisms,which impose im portant selective forces upon their ***,in accordance with the A djustm ent to parasite pressure hypothesis,it is expected that defenses among hosts vary relative to the selective pressure imposed by *** to the latitudinal gradient in diversity,species richness and abundance of parasites peak near the *** uropygial gland is an im portant defensive exocrine gland against pathogens in *** of the uropygial gland has been proposed to vary among species of birds because of divergent selection by pathogens on their ***,we should expect that bird species from the tropics should have relatively larger uropygial glands for their body size than species from higher ***,this hypothesis has not yet been ***,we analyze the size of the uropygial gland of 1719 individual birds belonging to 36 bird species from 3 Neotropical(Peru)and 3 temperate areas(Spain).Relative uropygial gland volum e was 12.52%larger in bird species from the tropics than from temperate *** finding is consistent w ith the relative size of this defensive organ being driven by selective pressures imposed by *** also explored the potential role of this gland as a means of avoiding haemosporidian infection,showing that species with large uropygial glands for their body size tend to have lower mean prevalence of haemosporidian infection,regardless o f their geographical *** result provides additional support for the assum ption that secretions from the uropygial gland reduce the likelihood of becoming infected with haemosporidians.

关键词： adjustment to parasite pressure hypothesis malaria Neotropical region preen oil temperate region

Semen analysis and sperm function testing

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Asian Journal of Andrology 2012年第1期14卷 6-13,174页

作者： Daniel R Franken sergio Oehninger Department of Obstetrics and Gynaecology Tygerberg Hospita Tygerberg Cape Town 7505 South Africa Department of Obstetrics and Gynaecology Eastern Virginia Medical School Jones Institute for Reproductive Medicine Norfolk VA 23507 USA

Despite controversy regarding the clinical value of semen analysis, male fertility investigation still relies on a standardized analysis of the semen parameters. This is especially true for infertility clinics in both developing and developed countries. Other optional tests or sophisticated technologies have not been widely applied. The current review addresses important changes in the analysis of semen as described in the new World Health Organization （WHO） manual for semen analysis. The most important change in the manual is the use of evidence-based publications as references to determine cutoff values for normality. Apart from the above mentioned changes, the initial evaluation and handling methods remain, in most instances, the same as in previous editions. Furthermore, the review evaluates the importance of quality control in andrology with emphasis on the evaluation of sperm morphology. WHO sperm morphology training programmes for Sub-Saharan countries were initiated at Tygerberg Hospital in 1995. The external qualitY control programme has ensured that the majority of participants have maintained their morphological reading skills acquired during initial training. This review reports on current sperm functional tests, such as the induced acrosome reaction, and sperm-zona pellucida binding assays, as well as the impact of sperm quality in terms of DNA integrity, and the relationship of sperm function tests to sperm morphology.

关键词： male infertility quality assurance semen analysis spermatozoa sperm concentration sperm function sperm morphology sperm motility

Alpha2-adrenergic receptor activation reinstates motor deficits in rats recovering from cortical injury

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2023年第4期18卷 875-880页

作者： Gabriela garcía-Díaz Laura ERamos-Languren Carmen Parra-Cid Joel Lomelí sergio Montes Camilo Ríos Antonio Bueno-Nava Ignacio Valencia-Hernández Rigoberto González-Piña Department of Pharmacology Section of Postgraduate Studies and ResearchHigh Medical SchoolInstituto Politécnico NacionalSalvador Díaz MirónAlcaldía Miguel HidalgoMexico CityMexico Department of Neurobiology of Aging and Brain Damage Coordination of Psychobiology and NeurosciencesFaculty of PsychologyNational Autonomous University of MexicoAv.Universidad 3040Col.Copilco UniversidadAlcaldía CoyoacánMexico CityMexico Direction of Research National Institute of Rehabilitation LGIICalz.Mexico-Xochimilco 289Col.Arenal de GuadalupeAlcaldía TlalpanMexico CityMexico Department of Pharmacology Multidisciplinary Academic Unit Reynosa-Aztlan ReynosaAutonomous University of Tamaulipascalle 16 y lago de ChapalaCol.AztlánTamaulipasMexico Department of Neurochemistry National Institute of Neurology and Neurosurgery MVSAv.Insurgentes Sur 3877Col.La FamaAlcaldia TlalpanMexico CityMexico Department of Special Education University of the AmericasPuebla 223Col.RomaAlcaldía CuauhtémocMexico CityMexico

Norepinephrine plays an important role in motor functional recovery after a brain injury caused by ferrous *** of norepinephrine release by clonidine is correlated with motor deficits after motor cortex *** aim of this study was to analyze the role ofα-adrenergic receptors in the restoration of motor deficits in recovering rats after brain *** rats were randomly assigned to the sham and injury groups and then treated with the following pharmacological agents at 3 hours before and 8 hours,3 days,and 20 days after ferrous chloride-induced cortical injury:saline,clonidine,efaroxan(a selective antagonist ofα-adrenergic receptors)and clonidine+*** sensorimotor score,the immunohistochemical staining forα-adrenergic receptors,and norepinephrine levels were *** hours post-injury,the sensorimotor score and norepinephrine levels in the locus coeruleus of the injured rats decreased,and these effects were maintained 3 days ***,20 days later,clonidine administration diminished norepinephrine levels in the pons compared with the sham *** effect was accompanied by sensorimotor *** effects were blocked by *** conclusion,an increase inα-adrenergic receptor levels was observed after *** restores motor deficits in rats recovering from cortical injury,an effect that was prevented by *** underlying mechanisms involve the stimulation of hypersensitiveα-adrenergic receptors and inhibition of norepinephrine activity in the locus *** results of this study suggest thatαreceptor agonists might restore deficits or impede rehabilitation in patients with brain injury,and therefore pharmacological therapies need to be prescribed cautiously to these patients.

关键词： alpha2-adrenoceptors ambulatory behavior clonidine cortical injury efaroxan functional recovery immunohistochemistry motor deficit norepinephrine sensorimotor score

Acyclic Complexes and Gorenstein Rings

在线全文

学校读者我要写书评

暂无评论

Algebra Colloquium 2020年第3期27卷 575-586页

作者： sergio Estrada Alina Iacob Holly Zolt Departamento de Matematicas Universidad de MurciaMurcia 30100Spain Department of Mathematical Sciences Georgia Southern University StatesboroGA 30460-8093USA

For a given class of modules A,let A be the class of exact complexes having all cycles in A,and dw(A)the class of complexes with all components in *** by GL the class of Gorenstein injective *** prove that the following are equivalent over any ring R:every exact complex of injective modules is totally acyclic;every exact complex of Gorenstein injective modules is in every complex in dw(GL)is dg-Gorenstein *** analogous result for complexes of flat and Gorenstein flat modules also holds over arb计rary *** the ring is n-perfect for some integer n≥0,the three equivalent statements for flat and Gorenstein flat modules are equivalent with their counterparts for projective and projectively coresolved Gorenstein flat *** also prove the following characterization of Gorenstein *** R be a commutative coherent ring;then the following are equivalent:(1)every exact complex of FP-injective modules has all its cycles Ding injective modules;(2)every exact complex of flat modules is F-totally acyclic,and every R-modulc M such that M^(+)is Gorenstein flat is Ding injective;(3)every exact complex of injectives has all its cycles Ding injective modules and every R-module M such that is Gorenstein flat is Ding *** R has finite Krull dimension,statements(1)-(3)are equivalent to(4)R is a Gorenstein ring(in the sense of Iwanaga).

关键词： totally acyclic complex Gorenstein injective module Gorenstein projective module Gorenstein flat module Ding injective module