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Dendritic Growth, Eutectic Features and Their Effects on Hardness of a Ternary Sn–Zn–Cu Solder Alloy

Acta metallurgica Sinica(English Letters) 2017年第6期30卷 528-540页

作者： Bismarck Luiz Silva Rodrigo Valenzuela Reyes Amauri Garcia Joséeduardo Spinelli Department of materials Engineering Federal University of Rio Grande do Norte-UFRNNatalRN 59078-970Brazil Department of materials Engineering Federal University of Sao Carlos-UFSCarSao CarlosSP 13565-905Brazil Department of manufacturing and materials Engineering University of CampinasUNICAMPCampinasSP 13083-860Brazil

The present investigation is based on the results of a directionally solidified （DS） Sn-9 wt%Zn-2 wt%Cu alloy, including primary/secondary/tertiary dendrite arm spacings of the Sn-rich matrix, the morphologies of the eutectic mixture and the corresponding interphase spacing, the nature and proportion of the Cu-Zn intermetallic compound （ImC）. The main purpose is to establish interrelations of these microstructure features with experimental solidification thermal parameters, such as cooling rates and growth rates （v）, macrosegregation and hardness. Such interrelations are interesting for both industry and academy since they represent a tool permitting the preprogramming of final properties based on the design of the microstructure. In the case of Sn-Zn-Cu alloys, hardly anything is known about the combined effects of the length scale of the microstructure and fraction and distribution of the primary ImC on hardness. The alloy microstructure is composed of a β-Sn dendritic region, surrounded by a eutectic mixture of α-Zn and β-Sn phases and the γ-Cu5Zn8 ImC. The eutectic interphase spacing varies in the range 1.2-3.6 μm, with the α-Zn phase having a globular morphology for ν 〉 0.5 mm/s and a needle-like morphology for ν 〈 0.3 mm/s. A modified Hall-Petch-type experimental expression relating hardness to the interphase spacing is proposed.

关键词： Sn-Zn-Cu solder alloy Solidification microstructure Eutectic morphology Hardness

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Design of a Novel Exoskeleton with Passive magnetic Spring Self-locking and Spine Lateral Balancing

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Journal of Bionic Engineering 2024年第1期21卷 236-255页

作者： Jhon F.Rodríguez-León Betsy D.m.Chaparro-Rico Daniele Cafolla Francesco Lago eduardo Castillo-Castañeda Giuseppe Carbone Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada Unidad Querétaro MecatronicaInstituto Politécnico NacionalCerro Blanco 14176090 Colinas del CimatarioQuerétaroMexico Department of mechanical Energy and Management EngineeringUniversity of CalabriaVia P.Bucci Cubo 46 C87036 RendeItaly Faculty of Science and Engineering Department of Computer ScienceSwansea UniversitySwanseaUK CESTER University of Cluj-NapocaCluj-NapocaRomania

This paper proposes a new upper-limb exoskeleton to reduce worker physical *** proposed design is based on a novel PRRRP(P-Prismatic;R-Revolute)kinematic chain with 5 passive Degrees of Freedom(DoF).Utilizing a magnetic spring,the proposed mechanism includes a specially designed locking mechanism that maintains any desired task *** proposed exoskeleton incorporates a balancing mechanism to alleviate discomfort and spinal torsional effects also helping in limb weight *** paper reports specific models and simulations to demonstrate the feasibility and effectiveness of the proposed *** experimental characterization is performed to validate the performance of the mechanism in terms of forces and physical strain during a specific application consisting of ceiling-surface drilling *** obtained results preliminarily validate the engineering feasibility and effectiveness of the proposed exoskeleton in the intended operation task thereby requiring the user to exert significantly less force than when not wearing it.

关键词： Assistive mechanism Exoskeleton Locking mechanism Bionic robot

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Hydrothermal alteration of the surface volcanic rocks at the Acoculco geothermal field,mexico:a multi-parametric approach

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Acta Geochimica 2024年第6期43卷 1037-1053页

作者： America Yosiris García-Soto Kailasa Pandarinath ESantoyo eduardo Gonzalez-Partida Instituto de Energías Renovables Universidad Nacional Autónoma de MéxicoPriv.Xochicalco s/no.Col.CentroApartado Postal 3462580 TemixcoMorelosMexico Centro de Geociencias UNAMApartado Postal 1-74276001 QuerétaroQuerétaroMexico

The studies on hydrothermal alteration-induced eff ects in surface and subsurface rocks provide useful information in the characterization and exploitation of a geothermal ***,these studies are based on traditional,and reliable methods like petrography(primary and secondary minerals,and grade of alteration),and geochemistry(mobility of elements,changes in mass and concentration of elements,and fluid inclusions).Recently,apart from these established methods,some methods based on the geochemical(Chemical Index of Alteration,CIA;Weathering Index of Parkar,WIP;Loss on Ignition,LOI;and Sulfur,S)and rock magnetic properties(magnetic susceptibility,χlf;and percentage frequency-dependent susceptibility,χfd%)are also being applied in the identification of whether a rock is an altered or a fresh *** Acoculco Geothermal Field(AGF),mexico,is characterized by high temperature and very low permeability,and it is considered a promissory Enhanced Geothermal *** following changes are observed in the rocks as a result of an increase in hydrothermal alteration:(1)an increase in CIA,LOI,and S values,and a decrease in WIP;(2)an increase in quartz and quartz polymorph minerals(silicification),and clay minerals(argillization);and(3)decrease inχlf *** AGF,the most altered surface acid rocks are characterized by entirely quartz and its polymorphs,and clay *** present study also indicates the applicability of the binary plots of major elements(felsic vs mafic component)and rock magnetic parameters(χlf vs.χfd%).The rock withχfd%value of 2-10 andχlf valuem^(3) kg^(-1)indicate the presence of single domain and stable single domain grains,which in turn suggests that it is an altered *** methods are simple to apply,rapid,reliable,and have the potential to become eff ective tools for the identifi cation of hydrothermally altered rocks during the initial stage of geothermal exploration.

关键词： Geothermal fields Hydrothermal alteration Surface rocks magnetic susceptibility Alteration indices

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Hyperelastic membrane Actuators:Analysis of Toroidal and Helical multifunctional Configurations

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Cyborg and Bionic Systems 2022年第1期2022卷 129-140页

作者： eduardo Perez-Guagnelli Joanna Jones Dana D.Damian Department of Automatic Control and Systems Engineering Universty of Shefield UK

Technologies that providemechanical assistance arerequired inthemdicalfeld,such asimplants that regenerate tssuethroughelongation and *** ofthe challenges is to develop actuators that combinethe benefits ofhigh axialextension at lowpressures,modularity,multifunction,and load bearing capabilities into one design while maintaining their shape and *** such a challenge wll provide implants with enhanced capacity for mechanical assistance to induce *** introduce two novel actuators(m2H)built of stacked Hyperelastic Balloning membrane Actuators(HBmAs)that can be realized using helical and toroidal *** restraining the HBmA expansion deterministicallyusing a semisoft exoskeleton,the actuatorsors areendoweded withh axial extension and radial expansion *** actuatorsare thus built of modules that canconfiguured different therapeutical needs and multifunctionality,to provideanatomically congruent *** desigl,fabricationtestin;and numerical and experimental validation ofthe *** can aaxiallyind6 in their helicaland toroidal configurations at input pressuresas low as 26 and 24 kPa,*** the axial module is used separately,its extension capacity reaches>170%.The m2H-HBmAs can perform independent and simultaneousxpansion and extension motions with negligible intraluminaldeformation as well as stand at least 1kg of axial force without *** m2H-HBmAs overcome the limitations ofhyperexpanding machines that show low resistance to *** envisage m2H-HBmAs as promising tools to perform tisueregeneration procedures.

关键词： restrain overcome skeleton

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Angiotensin Ⅱ receptor blockers and gastrointestinal adverse events of resembling sprue-like enteropathy:a systematic review

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Gastroenterology Report 2019年第3期7卷 162-167,I0001页

作者： Ayesha Kamal Christopher Fain Angela Park Peiqi Wang eduardo Gonzalez-Velez Daniel A.Leffler Susan m.Hutfless Department of medicine Division of GastroenterologyJohns Hopkins UniversityBaltimoreMDUSA Johns Hopkins Department of Surgery and Surgical SciencesJohns Hopkins UniversityBaltimoreMDUSA Division of Gastroenterology Beth Israel Deaconess Medical CenterBostonMAUSA Department of Epidemiology Johns Hopkins Bloomberg School of Public HealthBaltimoreMDUSA

Background:Olmesartan,an angiotensin Ⅱ receptor blocker(ARB),is associated with gastrointestinal symptoms resembling sprue-like *** have proposed that enteropathy may be a class effect rather than *** performed a systematic review to identify literature of sprue-like enteropathy for all ***:Case reports,case series and comparative studies of ARBs were searched on Pubmed and Embase databases through 21 November 2018 and then ***:A total of 82 case reports and case series as well as 5 comparative studies,including 248 cases,were selected and *** ARBs listed in the case reports were olmesartan(233 users;94.0%),telmisartan(5 users;2.0%),irbesartan(4 users;1.6%),valsartan(3 users;1.2%),losartan(2 users;0.8%)and eprosartan(1 user;0.4%).The periods between ARB initiation and onset of symptoms ranged from 2 weeks to 13 *** results were reported in 218 cases,in which 201 cases(92.2%)were villous atrophy and 131 cases(60.1%)were intraepithelial *** leucocyte antigen(HLA)testing was performed in 147 patients,among whom 105(71.4%)had HLA-DQ2 or HLA-DQ8 *** antibodies were tested in 169 patients,among whom 167(98.8%)showed negative *** exclusion from the diet failed to relieve symptoms of enteropathy in 127(97.7%)of 130 patients with *** remission of symptoms after discontinuation of ARB was reported in 233(97.4%)of the 239 patients with *** cases(2.8%)reported recurrence of symptoms after restarting olmesartan;rechallenge was not reported for the non-olmesartan *** retrospective studies conducted worldwide had inconsistent study designs(*** in periods of study and case definition)and ***:Although enteropathy is rare,clinicians should remain vigilant of this potential adverse event even years after medication initiation.

关键词： angiotensinⅡreceptor blockers olmesartan enteropathy diarrhea

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Identific tion of quantitative trait loci and associated candidate genes for pregnancy success in Angus–Brahman crossbred heifers

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Journal of Animal Science and Biotechnology 2024年第1期15卷 162-170页

作者： Quinn A.Hoorn Gabriel A.Zayas eduardo E.Rodriguez Laura m.Jensen Raluca G.mateescu Peter J.Hansen Department of Animal Sciences Donald Henry Barron Reproductive and Perinatal Biology Research Programand the Genetics InstituteUniversity of FloridaGainesvilleFLUSA School of Applied Systems Biology La Trobe UniversityBundooraVIC 3083Australia

Background In beef cattle, more than 50% of the energy input to produce a unit of beef is consumed by the female that produced the calf. Development of genomic tools to identify females with high genetic merit for reproductive function could increase the profitability and sustainability of beef *** Genome-wide association studies(GWAS) were performed using a single-step genomic best linear unbiased prediction approach on pregnancy outcome traits from a population of Angus–Brahman crossbred heifers. Furthermore, a validation GWAS was performed using data from another farm. Heifers were genotyped with the Bovine GGP F250 array that contains 221,077 SNPs. In the discovery population, heifers were bred in winter breeding seasons involving a single round of timed artificial insemination(AI) followed by natural mating for 3 months. Two phenotypes were analyzed: pregnancy outcome to first-service AI(PAI;n = 1,481) and pregnancy status at the end of the breeding season(PEBS;n = 1,725). The heritability was estimated as 0.149 and 0.122 for PAI and PEBS, respectively. In the PAI model, one quantitative trait locus(QTL), located between 52.3 and 52.5 mb on BTA7, explained about 3% of the genetic variation, in a region containing a cluster of γ-protocadherin genes and SLC25A2. Other QTLs explaining between 0.5% and 1% of the genetic variation were found on BTA12 and 25. In the PEBS model, a large QTL on BTA7 was synonymous with the QTL for PAI, with minor QTLs located on BTA5, 9, 10, 11, 19, and 20. The validation population for pregnancy status at the end of the breeding season were Angus–Brahman crossbred heifers bred by natural mating. In concordance with the discovery population, the large QTL on BTA7 and QTLs on BTA10 and 12 were *** In summary, QTLs and candidate SNPs identified were associated with pregnancy outcomes in beef heifers, including a large QTL associated with a group of protocadherin genes. Confirmation of these associations

关键词： Beef cattle Fertility GWAS QTL

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Plasma–wave interaction in helicon plasmas near the lower hybrid frequency

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Chinese Physics B 2022年第7期31卷 413-419页

作者： Yide Zhao Jinwei Bai Yong Cao Siyu Wu eduardo Ahedo mario merino Bin Tian Science and Technology on Vacuum Technology and Physics Laboratory Lanzhou Institute of PhysicsLanzhou 730000China School of mechanical Engineering and Automation Harbin Institute of TechnologyShenzhen 518055China Equipo de Propulsi´on Espacial y Plasmas(EP2) Universidad Carlos III de Madrid28911 Legan´esSpain

We study the characteristics of plasma–wave interaction in helicon plasmas near the lower hybrid ***(0D)dispersion relation is derived to analyze the properties of the wave propagation and a 1D cylindrical plasma–wave interaction model is established to investigate the power deposition and to implement the parametric *** is concluded that the lower hybrid resonance is the main mechanism of the power deposition in helicon plasmas when the RF frequency is near the lower hybrid frequency and the power deposition mainly concentrates on a very thin layer near the ***,it causes that the plasma resistance has a large local peak near the lower hybrid frequency and the variation of the plasma density and the parallel wavenumber lead to the frequency shifting of the local *** is found that the magnetic field is still proportional to the plasma density for the local maximum plasma resistance and the slope changes due to the transition.

关键词： helicon plasmas lower hybrid frequency power deposition

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Evidence for maternal transmission of a putative endosymbiont in the digestive gland of Pomacea canaliculata(Architaenioglossa,Ampullariidae)

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BIOCELL 2017年第2期41卷 59-61页

作者： eduardo KOCH ISRAEL A.VEGA ALFREDO CASTRO-VAZQUEZ Departamento de Biología Universidad Nacional de CuyoFacultad de Ciencias Exactas y Naturales Instituto Argentino de Investigaciones de las Zonas Aridas(IADIZA-CCT-mendoza) Instituto de Fisiología Universidad Nacional de CuyoFacultad de Ciencias Médicas IHEm Universidad Nacional de CuyoCONICET

The digestive gland of the apple snail Pomacea canaliculata lodges two types of pigmented corpuscles(identified as C and K corpuscles)which has been proposed as endosymbiont/*** corpuscular types are always present in the digestive gland of adult snails,they are released into the tubuloacinar lumen and are later expelled in the *** their part,hatchlings lack any C or K corpuscles in the digestive gland as well as in their feces,whereas C corpuscles appear in both the gland and feces within one week after ***,it is possible that the detritivorous hatchlings acquire the putative C-endosymbiont from feces in the sediments where they live,***‘lateral’or‘horizontal’*** possibility was put to test in an experiment in which we prevented any lateral transmission,by a 7-days aseptic culture,with no food,of aseptically obtained *** the end of the experiment,we observed that most juveniles had survived the culture period,and hence the digestive glands and feces of survivors were studied by light microscopy of resin embedded,toluidine blue-stained *** studied glands and fecal samples showed C *** is concluded that lateral transmission of the endosymbiont,if any,is not indispensable for the acquisition of the endosymbiont by hatchlings.

关键词： Pigmented corpuscles Ampullariidae Endosymbiosis Coevolution

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Floral biology and pollination mechanisms of four mexico-endemic Fuchsia species with contrasting reproductive systems

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Journal of Plant Ecology 2018年第1期11卷 123-135页

作者： Clementina González Anai Alvarez-Baños eduardo Cuevas CONACYT-Instituto de Investigaciones sobre los Recursos Naturales Universidad Michoacana de San Nicolás de HidalgoAv.San Juanito Itzícuaro s/nCol.Nueva EsperanzaMorelia Michoacán 58330México Facultad de Biología Universidad Michoacana de San Nicolás de HidalgoAv.Francisco J.Mújica S/NCiudad UniversitariaMoreliaMichoacán 58030México Departamento de Biología Vegetal y Ecología Universidad de SevillaApartado 109541080 SevillaSpain

Aims The evolution of the outstanding variation of reproductive systems in angiosperms has been considered an important driver of line-age *** related hermaphroditic and dioecious species with biotic pollination provide the opportunity to study and compare traits related to pollinator attraction and their con-sequences on reproductive components.A higher predictability of pollination syndromes is expected in dioecious species,which are dependent on pollinators,than in self-compatible hermaphroditic *** species may suffer pollen limitation depending on the quality of floral rewards and the kind and abundance of pollina-tors,whereas no pollen limitation is expected in hermaphroditic spe-cies with autonomous ***,in the absence of pollen limitation,more or better seeds are expected in dioecious species,according to the sexual specialization *** In natural populations of the hermaphroditic Fuchsia fulgens and Fuchsia arborescens and dioecious Fuchsia parviflora and Fuchsia obconica,all endemic to mexico,we first described flower phenol-ogy,flower production and longevity and nectar volume and ***,we evaluated the correspondence between floral visitors and pollination *** hermaphrodite plants,we determined the level of herkogamy and the potential for autonomous ***,we evaluated the effect of pollen limitation on fruit set and seed number and assessed seed germination for all *** Findings In contrast to our prediction,dioecious species did not show a higher correspondence between pollination syndromes and floral visitors than did hermaphrodites;however,male flowers exhib-ited a higher correspondence than female *** pollen limitation was detected in dioecious species,for which visitation rate did not differ between male and female *** her-maphroditic *** showed pollen limitation for seed number,despite the presence of auto

关键词： dioecy herkogamy hermaphroditism pollen limitation pollination syndromes

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Comparative Analysis of Different Evaluation Functions for Protein Structure Prediction Under the HP model

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Journal of Computer Science & Technology 2013年第5期28卷 868-889页

作者： mario Garza-Fabre eduardo Rodriguez-Tello Gregorio Toscano-Pulido Information Technology Laboratory CINVESTAV-Tamaulipas Km.5.5 Carretera Ciudad Victoria-Soto La Marina 87130 Ciudad Victoria Tamaulipas México

The HP model for protein structure prediction abstracts the fact that hydrophobicity is a dominant force in the protein folding process. This challenging combinatorial optimization problem has been widely addressed through metaheuristics. The evaluation function is a key component for the success of metaheuristics; the poor discrimination of the conventional evaluation function of the HP model has motivated the proposal of alternative formulations for this component. This comparative analysis inquires into the effectiveness of seven different evaluation functions for the HP model. The degree of discrimination provided by each of the studied functions, their capability to preserve a rank ordering among potential solutions which is consistent with the original objective of the HP model, as well as their effect on the performance of local search methods are analyzed. The obtained results indicate that studying alternative evaluation schemes for the HP model represents a highly valuable direction which merits more attention.

关键词： evaluation function protein structure prediction metaheuristics combinatorial optimization bioinformatics

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