检索结果-南通市图书馆

Journal of Magnesium and Alloys 2024年第5期12卷 1931-1943页

作者： Farid Bahari-Sambran fernando Carreno C.M.Cepeda-Jiménez Alberto Orozco-Caballero Physical Metallurgy Department CENIM-CSICAv.Gregorio del Amo 828040 MadridSpain Department of Mechanical Engineering Chemistry and Industrial DesignPolytechnic University of MadridRonda de Valencia 328012MadridSpain

The aim of this work is to predict,for the first time,the high temperature flow stress dependency with the grain size and the underlaid deformation mechanism using two machine learning models,random forest(RF)and artificial neural network(ANN).With that purpose,a ZK30 magnesium alloy was friction stir processed(FSP)using three different severe conditions to obtain fine grain microstructures(with average grain sizes between 2 and 3μm)prone to extensive superplastic *** three friction stir processed samples clearly deformed by grain boundary sliding(GBS)deformation mechanism at high *** maximum elongations to failure,well over 400% at high strain rate of 10^(-2)s^(-1),were reached at 400℃ in the material with coarsest grain size of 2.8μm,and at 300℃ for the finest grain size of 2μ***,the superplastic response decreased at 350℃ and 400℃ due to thermal instabilities and grain coarsening,which makes it difficult to assess the operative deformation mechanism at such *** work highlights that the machine learning models considered,especially the ANN model with higher accuracy in predicting flow stress values,allow determining adequately the superplastic creep behavior including other possible grain size scenarios.

关键词： Machine learning Artificial intelligence Magnesium alloys Superplasticity Friction stir processing Grain coarsening

Stochastic seismic inversion and Bayesian facies classification applied to porosity modeling and igneous rock identification

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2024年第2期21卷 918-935页

作者： Fábio Júnior Damasceno Fernandes Leonardo Teixeira Antonio fernando Menezes Freire Wagner Moreira Lupinacci Exploratory Interpretation and Reservoir Characterization Group(GIECAR) Department of Geology and GeophysicsFederal Fluminense UniversityNiter oiRJ24210-346Brazil Petrobras Rio de JaneiroRJ20231-030Brazil National Institute of Science and Technology of Petroleum Geophysics(INCT-GP/CNPQ) Niter oiRJ24210-346Brazil

We apply stochastic seismic inversion and Bayesian facies classification for porosity modeling and igneous rock identification in the presalt interval of the Santos Basin. This integration of seismic and well-derived information enhances reservoir characterization. Stochastic inversion and Bayesian classification are powerful tools because they permit addressing the uncertainties in the model. We used the ES-MDA algorithm to achieve the realizations equivalent to the percentiles P10, P50, and P90 of acoustic impedance, a novel method for acoustic inversion in presalt. The facies were divided into five: reservoir 1,reservoir 2, tight carbonates, clayey rocks, and igneous rocks. To deal with the overlaps in acoustic impedance values of facies, we included geological information using a priori probability, indicating that structural highs are reservoir-dominated. To illustrate our approach, we conducted porosity modeling using facies-related rock-physics models for rock-physics inversion in an area with a well drilled in a coquina bank and evaluated the thickness and extension of an igneous intrusion near the carbonate-salt interface. The modeled porosity and the classified seismic facies are in good agreement with the ones observed in the wells. Notably, the coquinas bank presents an improvement in the porosity towards the top. The a priori probability model was crucial for limiting the clayey rocks to the structural lows. In Well B, the hit rate of the igneous rock in the three scenarios is higher than 60%, showing an excellent thickness-prediction capability.

关键词： Stochastic inversion Bayesian classification Porosity modeling Carbonate reservoirs Igneous rocks

Dietary xylo‑oligosaccharides and arabinoxylans improved growth efficiency by reducing gut epithelial cell turnover in broiler chickens

在线全文

学校读者我要写书评

暂无评论

Journal of Animal Science and Biotechnology 2024年第3期15卷 1325-1335页

作者： Carla castro Shahram Niknafs Gemma Gonzalez‑Ortiz Xinle Tan Michael R.Bedford Eugeni Roura Centre for Nutrition and Food Sciences Queensland Alliance for Agriculture and Food InnovationThe University of QueenslandSt LuciaQLD 4072Australia AB Vista MarlboroughWiltshire SN84ANUK

Background One of the main roles of the intestinal mucosa is to protect against environmental ***-mentation of xylo-oligosaccharides(XOS)is known to selectively stimulate the growth of beneficial intestinal bacteria and improve gut health and function in *** may have an impact on the integrity of the intestinal epithelia where cell turnover is critical to maintain the compatibility between the digestive and barrier *** aim of the study was to evaluate the effect of XOS and an arabinoxylan-rich fraction(AXRF)supplementation on gut func-tion and epithelial integrity in broiler *** A total of 128 broiler chickens(Ross 308)were assigned into one of two different dietary treatments for a period of 42 d:1)control diet consisting of a corn/soybean meal-based diet;or 2)a control diet supplemented with 0.5%XOS and 1%*** treatment was randomly distributed across 8 pens(n=8)with 8 chickens *** intake and body weight were recorded *** d 42,one male chicken per pen was selected based on aver-age weight and euthanized,jejunum samples were collected for proteomics *** Dietary XOS/AXRF supplementation improved feed efficiency(P<0.05)from d 1 to 42 compared to the con-trol *** analysis was used to understand the mechanism of improved efficiency uncovering 346 dif-ferentially abundant proteins(DAP)(Padj<0.00001)in supplemented chickens compared to the non-supplemented *** the jejunum,the DAP translated into decreased ATP production indicating lower energy expenditure by the tissue(e.g.,inhibition of glycolysis and tricarboxylic acid cycle pathways).In addition,DAP were associated with decreased epithelial cell differentiation,and migration by reducing the actin polymerization ***-ting the two main pathways together,XOS/AXRF supplementation may decrease around 19%the energy required for the maintenance of the gastrointestinal *** Dietary XOS/AXRF supplementation improved gr

关键词： Actin Arabinoxylans Broiler Cell turnover Energy metabolism Jejunum Xylo-oligosaccharides

Kentish Plover(Charadrius alexandrinus) and Little Tern(Sternula albifrons) prefer shells for nesting:A field experiment

在线全文

学校读者我要写书评

暂无评论

Avian Research 2024年第1期15卷 55-59页

作者： Macarena castro Andrés De la Cruz Nuria Martin-Sanjuan Alejandro Pérez-Hurtado Instituto Universitario de Investigacion Marina(INMAR) Campus de Excelencia Internacional del Mar(CEIMAR)Departamento de BiologíaUniversidad de CadizPuerto RealSpain Servicios centrales de Investigacion Salinas de la Esperanza Universidad de CadizPuerto RealSpain

Shorebird populations are declining worldwide,mainly due to human disturbances and loss of coastal ***,supratidal habitats as saltpans could play a role in buffering human *** have shown to be important as feeding or breeding sites of some shorebird species.A potential conservation strategy to increase shorebird populations in saltpans is to manipulate the cues that birds use to select optimal breeding *** it is hypothesized that shorebirds are attracted to bivalve shells due to the advantages they *** this hypothesis,we supplemented a restored saltpan in 2019 and 2021 with bivalve shells,expecting an increase in the number of breeding birds’ *** than 75% of Kentish Plover(Charadrius alexandrinus) and Little Tern(Sternula albifrons) nests were found in patches with shells in both *** best model for both species indicates that the presence of shells is the factor that most correlates with the location of *** probability of choosing one place over another to settle their nest increases in areas with an abundance of shells,double in the case of the Kentish Plover and triple in the case of the Little *** result of this study may constitute a valuable tool for attracting birds to restored saltpans and could contribute to the success of expensive restoration projects where time is usually a constraint.

关键词： Habitat management Nest site selection Saltpan restoration Shell supplementation Shorebirds

Nonlinear Model Predictive Controller for Compensations of Single Line-to-ground Fault in Resonant Grounded Power Distribution Networks

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 2024年第4期12卷 1113-1125页

作者： Warnakulasuriya Sonal Prashenajith fernando Mostafa Barzegar-Kalashani Md Apel Mahmud Shama Naz Islam Nasser Hossenzadeh Faculty of Engineering and Environment Northumbria UniversityNewcastleUK School of Software and Electrical Engineering Swinburne University of TechnologyHawthornAustralia School of Engineering Deakin UniversityWaurn PondsAustralia

An nonlinear model predictive controller(NMPC)is proposed in this paper for compensations of single line-to-ground(SLG)faults in resonant grounded power distribution networks(RGPDNs),which reduces the likelihood of power line bushfire due to electric *** current compensation(RCC)inverters with arc suppression coils(ASCs)in RGPDNs are controlled using the proposed NMPC to provide appropri-ate compensations during SLG *** proposed NMPC is incorporated with the estimation of ASC inductance,where the estimation is carried out based on voltage and current measure-ments from the neutral point of the power distribution *** compensation scheme is developed in the discrete time using the equivalent circuit of *** proposed NMPC for RCC inverters ensures that the desired current is in-jected into the neutral point during SLG faults,which is veri-fied through both simulations and control hardware-in-the-loop(CHIL)*** results are also presented against an integral sliding mode controller(ISMC)by demon-strating the capability of power line bushfire mitigation.

关键词： Fault current phase voltage nonlinear model predictive controller(NMPC) parameter adaptation parametric uncertainty power line bushfire

Predicting outcomes after kidney transplantation: Can Pareto’s rules help us to do so?

在线全文

学校读者我要写书评

暂无评论

World Journal of Transplantation 2024年第1期14卷 9-11页

作者： fernando M Gonzalez Francisca Gonzalez Cohens Department of Nephrology Faculty of MedicineUniversidad de ChileSantiago 7500922Chile Web Intelligence Centre Faculty of Physics and Mathematical SciencesSantiago 7500922Chile

Kidney transplantation is the best option for kidney replacement therapy,even considering that most of the times the grafts do not survive as long as their *** the Khalil et al's experience,published in this issue of the Journal,they analyze their second kidney graft survival and describe those significant predictors of early *** editorial comments on the results and put in perspective that most of the times,long-term graft survival could be inadvertently jeopardized if the immunosuppressive therapy is reduced or withdrawn for any reason,and that it could happen frequently if the transplant physician intends to innovate with the clinical care without proper evidence-based data.

关键词： Kidney transplantation Graft survival Acute rejection Interstitial fibrosis and tubular atrophy Immunosuppression

A Novel Derivation of Black Hole Entropy in all Dimensions from Truly Point Mass Sources

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of High Energy Physics, Gravitation and Cosmology 2024年第3期10卷 1017-1028页

作者： Carlos castro Perelman Bahamas Advanced Science Institute and Conferences Ocean Heights Stella Maris Long Island Bahamas Ronin Institute Haddon Place Montclair USA

It is explicitly shown how the Schwarzschild Black Hole Entropy (in all dimensions) emerges from truly point mass sources at r=0due to a non-vanishing scalar curvature involving the Dirac delta distribution. In order to achieve this, one is required to extend the domain of r to negative values −∞≤r≤+∞. It is the density and anisotropic pressure components associated with the point mass delta function source at the origin r=0which furnish the Schwarzschild black hole entropy in all dimensions D≥4after evaluating the Euclidean Einstein-Hilbert action. Two of the most salient results are i) that the observed spacetime dimension D=4is precisely singled out from all the other dimensions when the strong and weak energy conditions are met, and ii) the point mass source described in this work is not the result of a spherically symmetric gravitational collapse of a star as described by the Oppenheimer-Snyder model because we are not neglecting the pressure. As usual, it is required to take the inverse Hawking temperature βHas the length of the circle Sβ1obtained from a compactification of the Euclidean time in thermal field theory which results after a Wick rotation, it=τ, to imaginary time. This approach can be generalized to the Reissner-Nordstrom and Kerr-Newman metrics. The physical implications of this finding warrant further investigation since it suggests a profound connection between the notion of gravitational entropy and spacetime singularities.

关键词： General Relativity Black Holes Entropy Strings

Seventeenth-century Seville houses:a survey by the Alarife Juan De Legarra(1637)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Built Heritage 2024年第2期8卷 13-32页

作者： Pilar Moya-Olmedo María Núñez-González fernando Vilaplana-Villajos Departamento de Ideación Gráfica Arquitectónica Escuela Técnica Superior de Arquitectura Universidad Politécnica de MadridAv.de Juan de Herrera 428040MadridSpain Departamento de Expresión Gráfica Arquitectónica Escuela Técnica Superior de Arquitectura Universidad de SevillaAv.de Reina Mercedes 2Seville41012Spain

Despite the wealth of preserved information,research on the domestic architecture of Seville has been *** of this historical data is available in survey books that were formally compiled in Seville from the Modern Age *** books had detailed descriptions and sometimes illustrations provided by surveyors who were commissioned by owners or *** intention of this study is to illustrate that the information contained in building surveys goes beyond simple descriptions or measurements often accompanied by *** are a comprehensive account that,even centuries later,help reconstruct the architecture,material culture and everyday life that no longer *** research contributes to the understanding of the domestic architectural history of Seville by focusing on one specific survey(a collection of drawings and a written description)extracted from the Hospital de las Cinco Llagas Collection,which is found in the Seville Provincial Council *** least one of the drawings and the written survey can be attributed to the Alarife(architect or master builder)Juan de Legarra,who signed them in *** research explores the architectural development of the city,offering fresh insights into its architecture,heritage,and *** supplements existing historical,visual,and written records derived from prior studies with a meticulously curated ***,it uses visualisation techniques to reconstruct buildings,augmenting the *** endeavour has yielded anticipated benefits,particularly in facilitating visual *** surveys have proven to be invaluable for historical inquiry,yielding unexpected insights through the thorough analysis of both written and graphic sources which serve as a basis for hypothetical construction plans due to their detailed ***,this study has contributed to enriching both historical and architectural *** incorporation of digital technologies into this architec

关键词： Historical documentation Survey Cultural heritage Virtual architecture Domestic architecture Archaeology

Rotating effects on the photoionization cross-section of a 2D quantum ring

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2024年第10期76卷 153-159页

作者： Carlos Magno O Pereira Frankbelson dos S Azevedo Luís fernando C Pereira Edilberto O Silva Departamento de Física Universidade Federal do Maranh?o

In this article, we investigate the nonrelativistic quantum motion of a charged particle within a rotating frame, taking into account the Aharonov–Bohm(AB) effect and a uniform magnetic field. Our analysis entails the derivation of the equation of motion and the corresponding radial equation to describe the system. Solving the resulting radial equation enables us to determine the eigenvalues and eigenfunctions, providing a clear expression for the energy levels. Furthermore,our numerical analysis highlights the substantial influence of rotation on both energy levels and optical properties. Specifically, we evaluate the photoionization cross-section with and without the effects of rotation. To elucidate the impact of rotation on the photoionization process of the system, we present graphics that offer an appealing visualization of the intrinsic nature of the physics involved.

关键词： Aharonov-Bohm effect photoionization cross-section quantum ring rotating effect

Individual and geospatial factors associated with receipt of colorectal cancer screening:a state-wide mixed-level analysis

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Family Medicine and Community Health 2024年第S2期12卷 18-25页

作者： Jennifer E Bayly Mara A Schonberg Marcia C castro Kenneth J Mukamal Beth Israel Deaconess Medical Center BostonMassachusettsUSA Harvard Medical School BostonMassachusettsUSA Department of Global Health and Population Harvard T H Chan School of Public HealthBostonMassachusettsUSA

Background Colorectal cancer(CRC)is the second leading cause of cancer death in US adults but can be reduced by *** roles of individual and contextual factors,and especially physician supply,in attaining universal CRC screening remains *** We used data from adults 50-75 years old participating in the 2018 New York(NY)Behavioural Risk Factor Surveillance System linked to county-level covariates,including primary care physician(PCP)density and gastroenterologist(GI)*** were analysed in *** analyses included(1)ecological and geospatial analyses of county-level CRC screening prevalence and(2)individual-level Poisson regression models of receipt of screening,adjusted for socioeconomic and county-level contextual *** Mean prevalence of up-to-date CRC screening was 71%(95%CI 70%to 73%)across NY’s 62 ***-level CRC screening demonstrated significant spatial patterning(Global Moran’s I=0.14,p=0.04),consistent with the existence of county-level contextual *** both county-level and individual-level analyses,lack of health insurance was associated with lower likelihood of up-to-date screening(?−1.09(95%CI−2.00 to-0.19);adjusted prevalence ratio 0.68(95%CI 0.60 to 0.77)),even accounting for age,race/ethnicity and *** contrast,county-level densities of both PCPs and GIs were completely unassociated with screening at either the county or individual *** expected,other determinants at the individual level included education status and *** In this state-wide representative analysis,physician density was completely unassociated with CRC screening,although health insurance status remains strongly *** similar screening environments,broadened insurance coverage for CRC screening is likely to improve screening far more effectively than increased physician supply.

关键词： state screening county