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Effect of calcination temperature on steam reforming activity of Ni-based pyrochlore catalysts

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j.urnal of Rare Earths 2020年第7期38卷 711-718,I0002页

作者： daniel j.Haynes Dushyant Shekhawat David Berry Amitava Roy j.mes j.Spivey National Energy Technology Laboratory U.S.Department of Energy3610 Collins Ferry RdMorgantownWV26507 USA Louisiana State University Cain Department of Chemical Engineering3307 Patrick Taylor HallBaton RougeLA70803USA

This work served as the second part of a study evaluating the effect of calcination temperature(700-1000℃) on Ni-based lanthanum zirconate pyrochlore catalysts for methane steam reforming.A previous study(Haynes et ***.2017(43) 16744) provided a thorough characterization of the material properties for the catalysts used here,and this study focuses on the evaluation of catalytic *** activity was assessed by two different experimental studies:the effect of reaction temperature using a temperature programmed surface reaction(TPSR),and the effect of reaction *** results demonstrate a complex interaction between the Ni particles and surface LaOx species under the methane steam reforming ***,the material calcined at the lowest temperature(700℃) possesses the highest activity and selectivity,which is attributed to smaller and more welldispersed Ni particles on the surface,and,more importantly,a lesser degree La enrichment at the *** catalysts were deactivated by steam to NiO under all conditions tested,but at certain low reaction pressure(p=0.23 MPa) conditions the materials calcined at 700-900℃ are able to completely recover equilibrium activity in-situ that is then robust and stable under both low and high reaction pressures(p=1.8 MPa) suggesting the formation of a synergistic relationship between Ni and La for syngas ***,exposure of a fresh material to high reaction pressures leads to a rapid and irreversible loss in both CH4 conversion and syngas selectivity whether in the fresh(no pretreatment),or pretreated(steam,H2 or Ar only at 800℃) form for any *** mechanism for deactivation appears to be due to the presence of LaOx species that become mobile,possibly by the formation of La-OH,and covers the active Ni particles and inhibits sites responsible for the CH4 decomposition.

关键词： Nickel Pyrochlore Methane Steam reforming Catalyst Lanthanum enrichment

Recent advances in forensic anthropology:decomposition research

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Forensic Sciences Research 2018年第4期3卷 278-293页

作者： daniel j.Wescott Department of Anthropology Texas State UniversityForensic Anthropology Center at Texas StateSan MarcosTXUSA

Decomposition research is still in its infancy,but significant advances have occurred within forensic anthropology and other disciplines in the past several *** research in forensic anthropology has primarily focused on estimating the postmortem interval(PMI),detecting clandestine remains,and interpreting the context of the ***,while much of the work has focused on forensic-related questions,an interdisciplinary focus on the ecology of decomposition has also advanced our *** purpose of this article is to highlight some of the fundamental shifts that have occurred to advance decomposition research,such as the role of primary extrinsic factors,the application of decomposition research to the detection of clandestine remains and the estimation of the PMI in forensic anthropology *** research in decomposition should focus on the collection of standardized data,the incorporation of ecological and evolutionary theory,more rigorous statistical analyses,examination of extended PMIs,greater emphasis on aquatic decomposition and interdisciplinary or transdisciplinary research,and the use of human cadavers to get forensically reliable data.

关键词： Taphonomy postmortem interval carrion ecology decomposition

Distance assessment of detours by j.m ping spiders

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Current Zoology 2020年第3期66卷 263-273页

作者： Samuel AGUILAR-ARGUELLO daniel GERHARD Ximena j.NELSON School of Biological Sciences University of CanterburyPrivate Bag 4800Christchurch 8140New Zealand School of Mathem atics and Statistics University of CanterburyPrivate Bag 4800Christchurch 8140New Zealand

To take an indirect route(detour)in order to reach a specific target requires complex cognitive *** more demanding,from the cognitive point of view,is when the goal is only visible at the beginning of the *** spiders from the family Sa lticidae,vision is a key sensory modal-ity mediating navigation and prey *** acute vision allows them to perform complicated detours,possibly as a consequence of the multitude of potential routes in their typically complex 3-dimensional *** used a 4-route choice test,in which routes differed in being either short or long and in the presence or absence of a lure of a prey item,to investigate route assessment in 2 salticid species,Trite planiceps and Marpissa *** both species showed evidence of motivation to follow lured-routes,j.dging by the number of times they re-oriented toward them while detouring,we found that Trite chose short routes in preference to long routes,but did not prefer the *** contrast,Marpissa exhibited random route choice,although it ori-ented toward lured-routes more often than control routes(lure absent).Our results suggest that decision-making processes about which route to take occurs before embarking on a route,but this is cognitively *** exhibited cognitive limitations in which the lack of visibility of the goal affected ***,the severity of cognitive limitations depended on *** suggest that variability in spatial ability across the Salticidae may be related to the habitat complexity inhabited by each species.

关键词： cognition cognitive limitations decision-making detour behavior Salticidae spatial task

Contrasting sorption behaviours affecting groundwater arsenic concentration in Kandal Province,Cambodia

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Geoscience Frontiers 2019年第5期10卷 1701-1713页

作者： Laura A. Richards Maria j. Casanueva-Marenco daniel Magnone Chansopheaktra Sovann Bart E. van Dongen David A. Polya School of Earth and Environmental Sciences and Williamson Research Centre for Molecular Environmental Science The University of ManchesterWilliamson BuildingOxford RoadManchesterM13 9PLUK Department of Analytical Chemistry Institute of BiomoleculesFaculty of SciencesUniversity of CádizCádizSpain School of Geography University of LincolnBrayford PoolLincolnLincolnshireLN6 7TSUK Department of Environmental Science Royal University of Phnom PenhPhnom PenhCambodia

Natural arsenic (As) contamination of groundwater which provides drinking water and/or irrigation supplies remains a maj.r public health issue,particularly in South and Southeast Asia.A number of studies have evaluated various aspects of the biogeochemical controls on As mobilization in aquifers typical to this region,however many are predicated on the assumption that key biogeochemical processes may be deduced by sampled water *** validity of this assumption has not been clearly established even though the role of sorption/desorption of As and other heavy metals onto Fe/Mn (hydr) oxides is an important control in As ***,selective chemical extractions of sand-rich and clay-rich sediments from an As-affected aquifer in Kandal Province,Cambodia,were undertaken to explore the potential role of partial re-equilibrium through sorption/desorption reactions of As and related solutes (Fe,Mn and P) between groundwater and the associated solid aquifer *** general,groundwater As is strongly affected by both pH and Eh throughout the study ***,contrasting sorption behaviour is observed in two distinct sand-dominated (T-Sand) and clay dominated (T-Clay) transects,and plausibly attributed to differing dominant lithologies,biogeochemical and/or hydrogeological ***/desorption processes appear to be re-setting groundwater As concentrations in both transects,but to varying extents and in different *** T-Sand,which is typically highly reducing,correlations suggest that dissolved As may be sequestered by sorption/re-adsorption to Fe-bearing mineral phases and/or sedimentary organic matter;in T-Clay Eh is a maj.r control on As mobilization although binding/occlusion of Fe-bearing minerals to sedimentary organic matter may also *** linear regression analysis was conducted with groups categorised by transect and by Eh,and the output correlations support the contrasting sorption behaviours encountered in this study area.I

关键词： Arsenic Groundwater Partial equilibrium Sorption Water-rock interactions Cambodia

Achieving work hardening by forming boundaries on the nanoscale in a Ti-based metallic glass matrix composite

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j.urnal of Materials Science & Technology 2020年第15期47卷 192-203页

作者： j.ng Fan Wei Rao j.nwei Qiao PKLiaw daniel Sopu daniel Kiener j.rgen Eckert Guozheng Kang Yucheng Wu College of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan030024China Key Laboratory of Interface Science and Engineering in Advanced Materials Ministry of EducationTaiyuan University of TechnologyTaiyuan030024China Key Laboratory of Advanced Technologies of Materials School of Mechanics and EngineeringSouthwest Jiaotong UniversityMinistry of Education of ChinaChengdu610031China Department of Materials Science and Engineering The University of TennesseeKnoxvilleTN37996-2200USA Technische Universitat Darmstadt Institut fiir MaterialwissenschaftFachgebiet MaterialmodellierungOtto-Bemdt-Strasse 3D-64287DarmstadtGermany Erich Schmid Institute of Materials Science Austrian Academy of SciencesJahnstra'e 12A-8700LeobenAustria Department of Materials Science Montanuniversitat LeobenJahnstra'e 12A-8700LeobenAustria

Achieving work hardening in metallic glass matrix composites(MGMCs) is the key to the extensive use of these attractive materials in structural and functional *** this study,we investigated the formation of nanoscale boundaries resulted from the interaction between matrix and dendrites,which favors the work-hardening deformation in an in-situ Ti41Zr32Ni6 Ta7 Be14 MGMC with β-Ti dendrites in a glassy matrix at room *** microstructures of samples after tension were observed by highresolution transmission electron microscopy(HRTEM) and X-ray diffraction(XRD).The work-hardening mechanism of the present composites involves:(1) appearance of dense dislocation walls(DDWs),(2)proliferation of shear bands,(3) fo rmation of boundaries on the nanoscale,and(4) interactions between hard and soft phases.A theoretical model combined with experimental data reveals the deformation mechanisms in the present work,proving that the in-situ dendrites with outstanding hardening ability in the glass matrix can provide the homogeneous deformation under tensile loading at room temperature.

关键词： Metallic glass matrix composites Plastic deformation Work hardening Dense dislocation walls Nanoscale boundaries

The practice of mine ventilation engineering

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International j.urnal of Mining Science and Technology 2015年第2期25卷 165-169页

作者： Wallace Keith Prosser Brian Stinnette j.daniel Mine Ventilation Services Inc.

The practice of ventilation is continually evolving with new technological advances developed in the mining *** recent years the advances in diesel engine technologies,ventilation modeling software,and ventilation management capacities have redefined the historical methods used to evaluate *** advances re-evaluate previous methods used to calculate the airflow requirements for the dilution of diesel exhaust *** software has become an integral part of planning and developing ventilation systems in partnership with graphical mine design software packages to generate realistic representations of the *** advances in ventilation control strategies through remote sensors and monitoring capabilities have been developed to results in cost *** there has been much advancement in mine ventilation technology,the practices and basic ventilation principals enacted through the ventilation engineer cannot be placated with technological advances only.

关键词： Modern ventilation Ventilation on demand Diesel Airflow evaluation Monitoring system

Simulations of a logistic-type model with delays for Chagas disease with insecticide spraying

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International j.urnal of Biomathematics 2017年第3期10卷 41-60页

作者： Nofe Al-Asuoad Tyler Pleasant Meir Shillor Hrishikesh Munugala daniel j. Coffield j.. Anna Maria Spagnuolo Department of Mathematics and Statistics Oakland University Rochester MI 48309 USA Harrison High School MI USA Novi High School Novi MI 48375 USA Mathematics Department University of Michigan-Flint Flint MI 48502 USA

This work studies and numerically simulates a logistic-type model for the dynamics of Chagas disease, which is caused by the parasite T. cruzi and affects millions of humans and domestic mammals throughout rural areas in Central and South America. A basic model for the disease dynamics that includes insecticide spraying was developed in Spagnuolo et al. （2010） [271 and consists of a delay-differential equation for the vectors and three nonlinear ordinary differential equations for the populations of the infected vectors, infected humans and infected domestic mammals. In this work, the vector equation is modified by using a logistic term with zero, one or two delays or time lags. The aim of this study is three-fold： to numerically study the effects of using different numbers of delays on the model behavior; to find if twice yearly insecticide spraying schedules improve vector control; and to study the sensitivity of the system to the delays in the case of two delays, by introducing randomness in the delays. It is found that the vector equation with different number of delays has very different solutions. The ＂best＂ day of spraying is the middle of Spring and twice annual sprayings cause only minor improvements in disease control. Finally, the model is found to be insensitive to the values of the delays, when the delays are randomly distributed within rather narrow intervals or ranges centered on the parameter values used in Coffield et al. （2014） [8].

关键词： Chagas disease logistic equation with delays epidemic dynamics nonlinear dynamical system simulations.

Glial cell line-derived neurotrophic factor as a treatment after spinal cord inj.ry

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Neural Regeneration Research 2018年第10期13卷 1733-1734页

作者： stephen d.ortmann daniel j.hellenbrand department of neurological surgery university of wisconsinmadisonwiusa

Spinal cord inj.ry（SCI）is a devastating trauma that currently affects 54 people out of every million,which is approximately 270,000people in the United States（National Spinal Cord Inj.ry Statistical Center,2013）.The effects of such an inj.ry can cause a loss of both motor and sensory function below the inj.ry site,normally leaving the patient unable to care for themselves entirely and relying on family and friends to provide personal *** there are no.

关键词： Glial cell line-derived neurotrophic factor as a treatment after spinal cord inj.ry GFR SCI

根据甲状腺癌危险程度分层行放射性碘治疗和选择性靶向治疗

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中华核医学与分子影像杂志 2018年第5期38卷 371-377页

作者：董萍李林 daniel A. Pryma Susan j. Mandel 四川大学华西医院核医学科成都610041 Division of Nuclear Medicine and Clinical Molecular Imaging Department of Radiology Perelman School of Medicine University of Pennsylvania Philadelphia Pennsylvania Division of Endocrinology Diabetes and Metabolism Department of Medicine Perelman School of Medicine University of PennsylvaniaPhiladelphia Pennsylvania

亲碘是分化型甲状腺癌的典型表现，可用放射性碘对该肿瘤进行有效治疗。在大多数分化型甲状腺癌患者中，常采用放射性碘来清除残留甲状腺组织（简称清甲），对于这类患者主张用最小有效剂量。辅助治疗可降低分化型甲状腺癌复发风险，但... 详细信息

亲碘是分化型甲状腺癌的典型表现，可用放射性碘对该肿瘤进行有效治疗。在大多数分化型甲状腺癌患者中，常采用放射性碘来清除残留甲状腺组织（简称清甲），对于这类患者主张用最小有效剂量。辅助治疗可降低分化型甲状腺癌复发风险，但相关患者的最佳纳入标准及具体治疗剂量尚不清楚。进展期分化型甲状腺癌患者能从最大放射性碘耐受剂量的治疗中获益。筛选适合清甲的患者及其治疗剂量是近期研究热点之一。近年来研发出一些用于治疗碘抵抗难治性分化型甲状腺癌的靶向药物，其中一种已通过美国食品与药品管理局（FDA）的批准，此外，多个临床试验正在评估单用靶向药物或靶向药物联合放射性碘治疗难治性分化型甲状腺癌的疗效。

关键词：甲状腺癌放射性碘治疗碘难治性疾病多激酶靶向治疗