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Activation characteristics of candidate structural materials for a near-term indian fusion reactor and the impact of their impurities on design considerations

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Plasma Science and Technology 2018年第6期20卷 186-193页

作者： h L SWAMi c DANANi A K ShAW institute for Plasma Research Gandhinagar Gujarat 382428 India homi Bhabha National institute (hBNi) Anushaktinagar Mumbai 400094 India

Activation analyses play a vital role in nuclear reactor *** analyses,along with nuclear analyses,provide important information for nuclear safety and maintenance *** analyses also help in the selection of materials for a nuclear reactor,by providing the radioactivity and dose rate levels after *** information is important to help define maintenance activity for different parts of the reactor,and to plan decommissioning and radioactive waste disposal *** study of activation analyses of candidate structural materials for near-term fusion reactors or iTER is equally essential,due to the presence of a highenergy neutron environment which makes decisive demands on material *** study comprises two parts; in the first part the activation characteristics,in a fusion radiation environment,of several elements which are widely present in structural materials,are *** reveals that the presence of a few specific elements in a material can diminish its feasibility for use in the nuclear *** second part of the study concentrates on activation analyses of candidate structural materials for near-term fusion reactors and their comparison in fusion radiation *** structural materials selected for this study,***-specific Reduced Activation Ferritic-Martensitic steel（iN-RAFMS）,P91-grade steel,stainless steel 316 LN iTER-grade（SS-316 LN-iG）,stainless steel 316 L and stainless steel 304,are candidates for use in iTER either in vessel components or test blanket *** is also included in this study because of its use for iTER plasma-facing *** study is carried out using the reference parameters of the iTER fusion *** activation characteristics of the materials are assessed considering the irradiation at an iTER equatorial *** presence of elements like Nb,Mo,co and Ta in a structural material enhance the activity level as well as the dose level,which has an

关键词： activation EASY nuclear safety fusion reactor structural materials

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Simulation of Vortex convection in a compressible Viscous Flow with Dynamic Mesh Adaptation

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Advances in Applied Mathematics and Mechanics 2014年第5期6卷 590-603页

作者： c.h.Zhou Department of Aerodynamics Nanjing University of Aeronautics and AstronauticsNanjing 210016China

in this work,vortex convection is simulated using a dynamic mesh adaptation *** each adaptation period,the mesh is refined in the regions where the phenomena evolve and is coarsened in the regions where the phenomena deviate since the last adaptation.A simple indicator of mesh adaptation that accounts for the solution progression is *** generation of dynamic adaptive meshes is based on multilevel refinement/*** efficiency and accuracy of the present procedure are validated by simulating vortex convection in a uniform *** unsteady compressible turbulent flows involving blade-vortex interactions are investigated to demonstrate further the applicability of the *** results agree well with the published experimental data or numerical results.

关键词： Mesh adaptation vortex-convection blade-vortex interaction unsteady flow timedependent problem shock-vortex interaction.

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Kcl:Eu^(2+) as a solar UV-c radiation dosimeter. Optically stimulated luminescence and thermoluminescence analyses

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Journal of Rare Earths 2009年第4期27卷 579-583页

作者： i.Aguirre de cárcer h.L.D'Antoni M.Barboza-Flores V.correcher F.Jaque Departamento Física de Materiales Universidad Autónoma Madrid Spain NASA Ames Research center Moffett Field California USA centro de investig ción en Física Universidad de Sonora México centro investigaciones Energía y Medioambientales (ciEMAT) Madrid Spain

The Kci：Eu2＋ system response to UV-c was investigated by analyzing the optically stimulated luminescence （OSL） and ther- mo-luminescence （TL） signal produced by ultraviolet light exposure at room temperature. it was found that after UV-c ***, OSL was produced on a wide band of visible wavelengths with decay time that varied by several orders of magnitude depending on the Eu2＋ aggregation state. in spite of the low intensity of solar UV-c reaching the Earth＇s surface in Madrid （40° N, 700 m a.s.1.）, it was possible to measure the UV-c radiation dose at 6：48 solar time by using the TL response of the Kci：Eu2＋ system and differentiate it from the ambient beta radiation dose.

关键词： thermo-luminescence rare-earth-doped alkali halides solar ultraviolet dosimeter environmental radiation

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combustion synthesis, characterization and luminescence properties of barium aluminate phosphor

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Journal of Rare Earths 2014年第9期32卷 806-811页

作者： A.h. Wako F.B Dejene h.c Swart Department of Physics University of the Free State (Qwaqwa Campus) Department of Physics University of the Free State

The blue-green emitting Eu2＋ and Nd3＋ doped polycrystalline barium aluminate （BaAi204：Eu2＋,Nd3＋） phosphor, was prepared by a solution-combustion method at 500 ℃without a post-annealing process. The characteristic variation in the structural and luminescence properties of the as-prepared samples was evaluated with regards to a change in the Ba/A1 molar ratio from 0.1：1 to 1.4：1. The morphologies and the phase structures of the products were characterized by scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, X-ray diffraction （XRD） and X-ray photoelectron spectroscopy （XPS）, while the optical properties were investigated using ultra-violet （UV） and photoluminescence （PL） spectroscopy, respectively. The XRD and TEM results revealed that the average crystallite size of the BaAl2O4：Eu2＋,Nd3＋ phosphor was about 70 urn. The broad-band UV-excited luminescence of the phosphors was observed at 2max=500 um due to transitions from the 4f^65d1 to the 4f7 configuration of the Eu2＋ ion. The PL results indicated that the main peaks in the emission and excitation spectrum of phosphor particles slightly shifted to the short wavelength due to the changes in the crystal field due to the structure changes caused by the variation in the quantity of the Ba ions in the host lattice.

关键词： BaAl2O4:Eu2+,Nd3+ persistence luminescence Eu2+ and Nd3+ doping rare earths

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comparative transcriptomics of anadromous and resident brook charr Salvelinus fontinalis before their first salt water transition

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current Zoology 2012年第1期58卷 158-170页

作者： Boulet, Marylène Normandeau, Éric Bougas, Bérénice Audet, céline mboulet@ubishops.ca Bernatchen, Louis iBiS (institut de Biologie intégrative et des Systèmes) Université Laval Québec QC G1V 0A6 Canada iSMER Université du Québec à Rimouski Rimouski QC G5L 3A1 Canada

Most salmonid taxa have an anadromous life history strategy, whereby fish migrate to saltwater habitats for a growth period before returning to freshwater habitats for spawning. Moreover, several species are characterized by different life history tactics whereby resident and anadromous forms may occur in genetically differentiated populations within a same species, as well as polymorphism within a population. The molecular mechanisms underlying the physiological differences between anadromous and resident forms during the first transition from freshwater to saltwater environments are only partially understood. insofar re- search has typically focused on species of the genus Salmo. here, using a 16,000 cDNA array, we tested the hypothesis that ana- dromous brook charr Salvelinus fontinalis are characterized by differences in their transcriptome relative to resident brook charr before the anadromous fish migration. Families originating from parapatric populations of anadromous and resident charr were reared in controlled environments mimicking natural temperature and photoperiod, and sampled in spring, while still in fresh wa- ter. While anadromous and resident charr showed similar transcriptome profiles in white muscle, they were characterized by striking differences in their gill transcriptome profiles. Genes that were upregulated in the gills of anadromous charr were princi- pally involved in metabolism （mitochondrial electron transport chain, glucose metabolism, and protein synthesis）, development （tissue differentiation） and innate immunity. We discuss the nature of these transcriptomic differences in relation to molecular mechanisms underlying the expression of anadromous and resident life history tactics and suggest that the anadromous charr express some of the molecular processes present in other migratory salmonids [current Zoology 58 （1）： 158-170, 2012].

关键词： Transcriptome Life history tactics Anadromy Migration to salt water Ecotypes Salmohids

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Measuring gravitational effect of superintense laser by spin-squeezed Bose-Einstein condensates interferometer

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chinese Physics B 2022年第5期31卷 265-273页

作者： Eng Boon Ng c.h.Raymond Ooi Department of Physics University of MalayaKuala Lumpur 50603Malaysia

We consider an extremely intense laser,enclosed by an atom *** gravitational potential generated from the high-intensity laser is solved from the Einstein field equation under the Newtonian *** compute the strength of the gravitational force and study the feasibility of measuring the force by the atom *** intense laser field from the laser pulse can induce a phase change in the interferometer with Bose-Einstein *** push up the sensitivity limit of the interferometer with Bose-Einstein condensates by spin-squeezing effect and determine the sensitivity gap for measuring the gravitational effect from intense laser by atom interferometer.

关键词： intense laser field atom interferometer Bose-Einstein condensates spin-squeezing

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Primary dendrite growth kinetics and rapid solidification mechanism of highly undercooled Ti-Al alloys

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Journal of Materials Science & Technology 2020年第5期40卷 47-53页

作者： Z.c.Luo h.P.Wang Department of Applied Physics Northwestern Polytechnical UniversityXi’an 710072China

The rapid solidification processes of undercooled Ti-(47,50,54)at.%Al alloys were investigated by electromagnetic levitation(EML)method combined with a high-speed photoelectric *** maximum undercoolings of the three liquid alloys were 376 K,352 K and 316 K,*** processes corresponding to the primary dendrite growth and subsequent phase transition were recorded at various *** primary dendrite growth velocity V meets a double exponential relationship with the undercooling ***,a novel formula with physical meaning is proposed to explain that the more ordered liquid metal atoms accelerate the primary dendrite *** recalescences are found at all undercoolings for Ti-47 at.%Al alloy and at high undercoolings for Ti-50 at.%Al *** microstructures of solidified Ti-47 at.%Al alloys successively appear as coarse lamellar dendrites and finally evolve to refined parallel lamellar dendrites with the increasing *** T rises,the microstructures of solidified Ti-50 at.%Al alloys appear from coarse primary dendrites and interdendritic dendrites to refined lamellar *** the process from low undercooling to high undercooling,the primary phase of undercooled Ti-54 at.%Al alloys changes from r-Ti(r)to r-TiAl(r)and the microstructures of solidified alloys evolve from spherical primary dendrites and matrix phases to cellular dendrite ***,for the Ti-(47,50)at.%Al,the transformation temperature of metastable intermediateγphase decreases with the increase of ***,the microhardness of the three solidified alloys reaches the maximum when the undercoolings are 185 K,270 K and 316 K,respectively.

关键词： Electromagnetic levitation Rapid solidification Dendrite growth Microstructure Microhardness

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Machine learning prediction of magnetic properties of Fe-based metallic glasses considering glass forming ability

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Journal of Materials Science & Technology 2022年第8期103卷 113-120页

作者： Xin Li Guangcun Shan c.h.Shek School of instrumentation Science and Opto-electronics Engineering Beihang UniversityBeijing 100191China Department of Materials Science and Engineering City University of Hong KongKowloon TongHong Kong SARChina

Fe-based metallic glasses(MGs)have shown great commercial values due to their excellent soft magnetic *** prediction with consideration of glass forming ability(GFA)is of great signifi-cance for developing novel functional Fe-based ***,theories or models established based on condensed matter physics exhibit limited accuracy and some *** this work,based on 618 Fe-based MGs samples collected from published works,machine learning(ML)models were well trained to predict saturated magnetization(B_(s))of Fe-based *** was treated as a feature using the experimental data of the supercooled liquid region(△T_(x)).Three ML algorithms,namely eXtreme gradient boosting(XGBoost),artificial neural networks(ANN)and random forest(RF),were *** feature selection and hyperparameter tuning,XGBoost showed the best predictive performance on the randomly split test dataset with determination coefficient(R^(2))of 0.942,mean absolute percent error(MAPE)of 5.563%,and root mean squared error(RMSE)of 0.078 T.A variety of feature importance rankings derived by XGBoost models showed that T_(x) played an important role in the predictive performance of the *** work showed the proposed ML method can simultaneously aggregate GFA and other features in ther-modynamics,kinetics and structures to predict the magnetic properties of Fe-based MGs with excellent accuracy.

关键词： Metallic glasses Soft magnetic properties Glass forming ability Machine learning Non-linear regression

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Numerical simulation on borehole breakout and borehole size effect using discrete element method

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international Journal of Mining Science and Technology 2020年第5期30卷 623-633页

作者： h.Lin W.h.Kang J.Oh i.canbulat B.hebblewhite School of Minerals and Energy Resources Engineering University of New South WalesSydneyNSW 2052Australia centre for infrastructure Engineering Western Sydney UniversityPenrithNSW 2751Australia

Estimation of horizontal stress magnitudes from borehole breakouts has been an attractive topic in the petroleum and mining industries,although there are critical research gaps that remain *** this paper,numerical simulation is conducted on Gosford sandstone to investigate the borehole breakout and its associated borehole size effect,including temperature *** discrete element method(DEM)model shows that the borehole breakout angular span is constant after the initial formation,whereas its depth propagates along the minimum horizontal stress *** indicates that the breakout angular span is a reliable parameter for horizontal stress *** borehole size effect simulations illustrated the importance of borehole size on breakout geometries in which smaller borehole size leads to higher breakout initiation stress as well as the stress re-distribution from borehole wall outwards through *** implies that the stress may be averaged over a distance around the borehole and breakout initiation occurs at the borehole wall rather than some distance into the *** addition,the numerical simulation incorporated the thermal effect which is widely encountered in deep geothermal *** on the results,the higher temperature led to lower breakout initiation stress with same borehole size,and more proportion of shear cracks was generated under higher *** indicates that the temperature might contribute to the micro-fracturing mode and hence influences the horizontal stress estimation results from borehole breakout *** simulation showed that breakout shape and dimensions changed considerably under high stress and high temperature conditions,suggesting that the temperature may need to be considered for breakout stress analysis in deep locations.

关键词： Borehole breakout Breakout angular span Borehole size effect Numerical simulation Thermal effect

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Determination of double-and single-stranded DNA breaks in bovine sperm is predictive of their fertilizing capacity

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Journal of Animal Science and Biotechnology 2023年第1期14卷 134-151页

作者： Jordi Ribas‑Maynou Ariadna Delgado‑Bermúdez Yentel Mateo‑Otero Estel Vinolas carlos O.hidalgo WSteven Ward Marc Yeste Biotechnology of Animal and human Reproduction(TechnoSperm) Faculty of SciencesInstitute of Food and Agricultural TechnologyUniversity of GironaC/Maria Aurèlia Campany69ES‑17003 GironaSpain. Unit of cell Biology Department of BiologyFaculty of SciencesUniversity of GironaES‑17003 GironaSpain. institute for Biogenesis Research Department of AnatomyBiochemistry&PhysiologyJohn A.Burns School of MedicineUniversity of Hawaii at ManoaHonoluluHI 96822USA. Department of Animal Selection and Reproduction The Regional Agri-Food Research and Development Service of Asturias(SERIDA)ES‑33394 GijónSpain. catalan institution for Research and Advanced Studies(icREA) ES‑08010 BarcelonaSpain.

Background:The analysis of chromatin integrity has become an important determinant of sperm *** frozenthawed bovine sperm,neither the sequence of post-thaw injury events nor the dynamics of different types of sperm DNA breaks are well *** aim of the present work was to describe such sperm degradation aftermath focusing on DNA damage dynamics,and to assess if this parameter can predict pregnancy rates in ***:A total of 75 cryopreserved ejaculates from 25 holstein bulls were evaluated at two post-thawing periods(0-2 h and 2-4 h),analyzing global and double-stranded DNA damage through alkaline and neutral comet assays,chromatin deprotamination and decondensation,sperm motility,viability,acrosomal status,and intracellular levels of total ROS,superoxides and *** of 59,605 females was conducted using sperm from the same bulls,thus obtaining the non-return to estrus rates after 90 d(NRR).Results showed an increased rate of double-stranded breaks in the first period(0-2 h:1.29±1.01%/h vs.2-4 h:0.13±1.37%/h;Phereas the rate of sperm with moderate+high single-stranded breaks was higher in the second period(0-2 h:3.52±7.77%/h vs.2-4h:21.06±11.69%/h;Ping sperm physiology,viability decrease rate was different between the two periods(0-2 h:-4.49±1.79%/h vs.2-4 h:-2.50±3.39%/h;P=0.032),but the progressive motility decrease rate was constant throughout post-thawing incubation(0-2 h:-4.70±3.42%/h vs.2-4 h:-1.89±2.97%/h;P>0.05).Finally,whereas no correlations between bull fertility and any dynamic parameter were found,there were correlations between the NRR and the basal percentage of highly-damaged sperm assessed with the alkaline comet(Rs=-0.563,P=0.003),between NRR and basal progressive motility(Rs=0.511,P=0.009),and between NRR and sperm with high ROS at 4 h post-thaw(Rs=0.564,P=0.003).conclusion:The statistically significant correlations found between intracellular ROS,sperm viability,sperm motility,DNA damage

关键词： cattle chromatin comet test DNA damage Fertility Sperm Sperm quality

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