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Modelling of compacted graphite cast iron solidification-Discussion of microstructure parameters

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China Foundry 2020年第2期17卷 144-149页

作者： Jacques Lacaze Urko de la Torre jon sertucha Anna Regordosa Centre Inter-universitaire de Recherche et d’Ingénierie des Matériaux(CIRIMAT) Universitéde ToulouseToulouseFrance Fundación AZTERLAN DurangoSpain

A melt maintained for hours in a press pour unit allowed the following changes over time from spheroidal graphite to compacted graphite iron by casting thermal cups at regular time *** provided extensive experimental information for checking the possibility of simulating solidification of compacted graphite irons by means of a microstructure modelling *** solidification,compacted graphite develops very much as lamellar graphite but with much less *** this basis,a simulation of the thermal analysis records was developed which considers solidification proceeding in a pseudo binary Fe-C *** simulated curves were compared with the experimental ones obtained from three representative alloys that cover the whole microstructure change during the holding of the *** most relevant result is that the parameter describing branching capability of graphite is the most important for reproducing the minimum eutectic temperature and the recalescence which are so characteristic of the solidification of compacted graphite cast irons.

关键词： compacted graphite irons thermal analysis stable eutectic metastable eutectic simulation

厚断面球铁部件凝固过程中蠕虫状石墨形成的热分析

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现代冶金（内蒙古） 2010年第2期 27-34页

作者： jon sertucha[西班牙] 乔林锁(译)

对近共晶球墨铸铁大试块中心的冷却曲线变化进行了分析，通过显微组织观察，给出蠕虫状石墨析出倾向。观察了低于共晶温度后的整个连续凝固过程：1）液态下初生石墨形核；2）奥氏体枝晶包围初生粒子的初始共晶反应过程；3）CHG晶粒大量... 详细信息

对近共晶球墨铸铁大试块中心的冷却曲线变化进行了分析，通过显微组织观察，给出蠕虫状石墨析出倾向。观察了低于共晶温度后的整个连续凝固过程：1）液态下初生石墨形核；2）奥氏体枝晶包围初生粒子的初始共晶反应过程；3）CHG晶粒大量形核和长大，以及第二相粒子的形核和长大，随后第二相粒子形成球状石墨共晶晶粒。共晶反应时，由于蠕虫状石墨的析出，再辉最大值首先增大，然后又减小。最有意义的是观察了由CHG影响的试块体积和由TA样杯检测的再辉之间的关系。

关键词：厚断面铸铁球铁石墨变质蠕虫状石墨热分析

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欧洲铸造业的新发展

欧洲铸造业的新发展

The importance of post-COVID condition phenotypes characterization to decipher the mechanisms underlying this post-viral syndrome

第十二届全国铸造年会暨2011中国铸造活动周

作者： Ramón Suárez Gorka Zarrabeitia jon sertucha 阿兹特兰工程及铸造部

随着国际铸造市场需求的不断增加及竞争的日趋激烈,欧洲铸造行业在生产工艺和铸件方面都达到了一个全新的高质量水平。不仅如此,这种高质量水平还使生产成本大幅削减,同时也满足了欧盟国家对铸造行业的环保要求。事实上,这几方面的要求...

随着国际铸造市场需求的不断增加及竞争的日趋激烈,欧洲铸造行业在生产工艺和铸件方面都达到了一个全新的高质量水平。不仅如此,这种高质量水平还使生产成本大幅削减,同时也满足了欧盟国家对铸造行业的环保要求。事实上,这几方面的要求也正是欧洲铸造业未来和发展的挑战,因此铸造厂家都在竭尽全力提高自己的铸造技术,加深对铸造原材料的了解。阿兹特兰中心就参与了许多客户在这方面的研究项目,例如:如何根据凝固过程来测量和控制熔融金属质量;具备更高机械性能的新等级铸造用铁的研究;模型板产量的提高（减少补缩系统）;铸件运送客户前对不增值操作流程的去除;加工过程中变量的改善及对变化结果的预计,从而稳定生产过程;铸件缺陷最小化;可替代原材料的灵活运用;降低能源成本等等。到目前为止,欧洲一些铸造厂家已经成功实现了以上研究项目,在铸造业发展方面占据了领先水平。

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World Journal of Pediatrics 2024年第6期20卷 633-634页

作者： jon Izquierdo-Pujol Sara Moron-Lopez IrsiCaixa and Institute for Health Science Research Germans Trias i Pujol(IGTP) Can Ruti CampusBadalonaSpain Biomedicine doctoral programme Faculty of BiologyUniversity of BarcelonaBarcelonaSpain CIBERINFEC MadridSpain

The coronavirus disease-19(COVID-19)outbreak,caused by the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),was declared a global pandemic in March *** has affected over 700 million people worldwide and resulted in almost 7 million deaths,equating to a 1%mortality *** present,the majority of COVID-19 cases are either asymptomatic or mild,typically resolving within two ***,between 1%and 10%of COVID-19 survivors do not fully recover and experience a post-viral syndrome referred to as"long COVID","post-acute COVID-19 syndrome"(PASC),or"post-COVID condition"(PCC).This post-viral syndrome affects both adult and pediatric ***,most of the studies published to date evaluate the adult population,leaving a gap in our understanding of its impact on children and adolescents.

关键词： acute mortality respiratory

High-temperature tribological performance of functionally graded Stellite 6/WC metal matrix composite coatings manufactured by laser-directed energy deposition

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Friction 2024年第3期12卷 522-538页

作者： Marta OSTOLAZA Alaitz ZABALA jon Inaki ARRIZUBIETA Iñigo LLAVORI Nagore OTEGI Aitzol LAMIKIZ Department of Mechanical Engineering University of the Basque Country UPV/EHUPlaza Torres Quevedo 1Bilbo 48013Spain Faculty of Engineering Mechanics and Industrial ProductionMondragon UnibertsitateaLoramendi 4Mondragon 20500Spain

Wear-driven tool failure is one of the main hurdles in the *** issue can be addressed through surface coating with ceramic-reinforced metal matrix ***,the maximum ceramic content is limited by *** this work,the tribological behaviour of the functionally graded WC-ceramic-particlereinforced Stellite 6 coatings is *** that end,the wear resistance at room temperature and 400°C is ***,the tribological analysis is supported by crack sensitivity and hardness evaluation,which is of utmost importance in the processing of composite materials with *** indicate that functionally graded materials can be employed to increase the maximum admissible WC content,hence improving the tribological behaviour,most notably at high ***,a shift from abrasive to oxidative wear is observed in high-temperature wear testing.

关键词： friction coating metal matrix composite functionally graded materials high temperature laserdirected energy deposition

Implications for brainstem recovery from studies in primates after sensory loss from arm

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Neural Regeneration Research 2024年第3期19卷 479-480页

作者： Jamie L.Reed Hui-Xin Qi jon H.Kaas Department of Psychology Vanderbilt UniversityNashvilleTNUSA

For decades,researchers have known that when neurons lose their activating inputs,they can atrophy and even *** example,removing sensory nerve inputs from the arm to the spinal cord after amputation or cutting the spinal nerves can shrink the post-synaptic target zones(e.g.,Woods et al.,2000).From touch receptors for the hand and arm,primary nerve afferents enter the spinal cord,and axons travel in the dorsal columns to target the cuneate nucleus(Cu)of the brainstem on the same side of the body(Figure 1).When sensory loss is unilateral,the overwhelming result is for the associated primary target zone to shrink in total size(cross-sectional area),as compared to the size of the opposite side.

关键词： brainstem shrink removing

A simple modification to the classical SIR model to estimate the proportion of under-reported infections using case studies in flu and COVID-19

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Infectious Disease Modelling 2024年第4期9卷 1147-1162页

作者： Leonid Kalachev jon Graham Erin L.Landguth Mathematical Sciences University of MontanaMissoulaUSA Center for Population Health Research School of Public and Community Health SciencesUniversity of MontanaMissoulaUSA

Background:Under-reporting and,thus,uncertainty around the true incidence of health events is common in all public health reporting *** the problem of underreporting is acknowledged in epidemiology,the guidance and methods available for assessing and correcting the resulting bias are ***:We aim to design a simple modification to the Susceptible e Infected e Removed(SIR)model for estimating the fraction or proportion of reported infection ***:The suggested modification involves rescaling of the classical SIR model producing its mathematically equivalent version with explicit dependence on the reporting parameter(true proportion of cases reported).We justify the rescaling using the phase plane analysis of the SIR model system and show how this rescaling parameter can be estimated from the data along with the other model ***:We demonstrate how the proposed method is cross-validated using simulated data with known disease cases and then apply it to two empirical reported data sets to estimate the fraction of reported cases in Missoula County,Montana,USA,using:(1)flu data for 2016e2017 and(2)COVID-19 data for fall of ***:We establish with the simulated and COVID-19 data that when most of the disease cases are presumed reported,the value of the additional reporting parameter in the modified SIR model is close or equal to one,so that the original SIR model is appropriate for data ***,the flu example shows that when the reporting parameter is close to zero,the original SIR model is not accurately estimating the usual rate parameters,and the re-scaled SIR model should be *** research demonstrates the role of under-reporting of disease data and the importance of accounting for underreporting when modeling simulated,endemic,and pandemic disease *** reporting the“true”number of disease cases will have downstream impacts on predictions of disease dynamics.A simple parameter adjustment

关键词： Modeling of epidemics SIR type models flu and COVID-19 Under-reporting parameter Proportion of reported disease cases

Technical efficiency of cocoa farms at varying elevation levels in Davao City, Philippines: implications to sustainable upland farming systems

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Journal of Mountain Science 2024年第1期21卷 33-48页

作者： Francis Levi A.DURANO jon Marx SARMIENTO Larry N.DIGAL Pedro A.ALVIOLA IV School of Management University of the Philippines MindanaoDavao City 8000Philippines

Elevation is one of many components that influence agriculture, and this in turn affects the level of both inputs and outputs of farmers. This article focuses on the productivity and technical efficiency of 100 cocoa farms using cross-sectional data from areas ranging from 190 to 1021 m above sea level which were classified as low, medium, and high elevation in Davao City, considered as the chocolate capital of the Philippines. Using stochastic frontier analysis, the results showed that the cost of inputs per ha and the number of cocoa trees per ha significantly increase yield. Farms at high elevations were less technically efficient, as this entails lower temperatures and increased rainfall, and cocoa farming in those areas and conditions can be more challenging, especially with changes in farming practices, terrain, and distance to markets. Other significant variables were age of cocoa farms, married farmers, and age of the farmers. Older farms may be more developed, farmers who are married benefit from their spouses being able to readily contribute as farm labor, and lastly, older farmers' inefficiency may likely stem from nonadaptation of newer farming practices. With an average technical efficiency of 0.61, 0.63, and 0.26 in low, medium, and high elevation areas, respectively, farmers therefore have an incentive to improve farm practices and consider topographical variations found in high elevation areas. Recommendations for the improvement of technical efficiency of cocoa farms are better connectivity to markets, enhancing farm practices, and continuation and improvement of government programs on cocoa with an added emphasis on research. For farmers in high elevation areas, mitigating solutions such as sustainable agriculture practices and ecolabelling are key to improving efficiency and minimizing the potential negative impact on upland farming systems. Moreover, such adaptation measures may also contribute to sustainability of cocoa farming in high elevation

关键词： Cocoa farms Cobb-Douglas production function Elevation Philippines Stochastic frontier analysis Technical efficiency

Batch Active Learning for Multispectral and Hyperspectral Image Segmentation Using Similarity Graphs

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Communications on Applied Mathematics and Computation 2024年第2期6卷 1013-1033页

作者： Bohan Chen Kevin Miller Andrea L.Bertozzi jon Schwenk Department of Mathematics University of CaliforniaLos Angeles520 Portola PlazaLosAngeles90095CAUSA Oden Institute for Computational Engineering and Sciences University of Texas at Austin201 E 24th StAustin 78712TXUSA Los Alamos National Laboratory Los AlamosNM 87545USA

Graph learning,when used as a semi-supervised learning(SSL)method,performs well for classification tasks with a low label *** provide a graph-based batch active learning pipeline for pixel/patch neighborhood multi-or hyperspectral image *** batch active learning approach selects a collection of unlabeled pixels that satisfy a graph local maximum constraint for the active learning acquisition function that determines the relative importance of each pixel to the *** work builds on recent advances in the design of novel active learning acquisition functions(e.g.,the Model Change approach in arXiv:2110.07739)while adding important further developments including patch-neighborhood image analysis and batch active learning methods to further increase the accuracy and greatly increase the computational efficiency of these *** addition to improvements in the accuracy,our approach can greatly reduce the number of labeled pixels needed to achieve the same level of the accuracy based on randomly selected labeled pixels.

关键词： Image segmentation Graph learning Batch active learning Hyperspectral image