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Sodium modification of zirconia catalysts for ethanol coupling to 1-butanol

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j.urnal of Energy Chemistry 2013年第1期22卷 58-64页

作者： j.seph T. Kozlowski robert j. Davis Department of Chemical Engineering University of Virginia

The influences of adding sodium to zirconia on the acid-base properties of the surface and on the catalytic conversion of ethanol and acetone were investigated. The rates of ethanol dehydration, dehydrogenation and coupling were evaluated in a fixed-bed flow reactor operating at temperatures from 613 to 673 K. The rate of acetone condensation was evaluated in the same reactor operating at 473-573 K. Addition of 1.0 wt% Na to ZrO2 decreased the rate of ethanol dehydration by more than an order of magnitude, which was consistent with a neutralization of acid sites evaluated by ammonia adsorption microcalorimetry. Addition of 1.0 wt% Na to ZrO2 also increased the base site density quantified by carbon dioxide adsorption microcalorimetry and the rate of acetone condensation. Although the rate of ethanol coupling was not increased by the addition of Na, the overall selectivity of ethanol to butanol was improved over the 1.0 wt% Na/ZrO2 sample because of the significant inhibition of ethanol dehydration.

关键词： Guerbet reaction alcohol condensation zirconia microcalorimetry acetone condensation

Overexpression of a Potato Sucrose Synthase Gene in Cotton Accelerates Leaf Expansion, Reduces Seed Abortion, and Enhances Fiber Production

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Molecular Plant 2012年第2期5卷 430-441页

作者： Shou-Min Xu Elizabeth Brill Danny j. Llewellyn robert T. Furbank Yong-Ling Ruan CSIRO Plant Industry GPO Box 1600 Canberra ACT 2601 Australia School of Environmental and Life Sciences University of Newcastle Newcastle NSW 2308 Australia

Sucrose synthase （Sus） is a key enzyme in the breakdown of sucrose and is considered a biochemical marker for sink strength, especially in crop species, based on mutational and gene suppression studies. It remains elusive, however, whether, or to what extent, increase in Sus activity may enhance sink development. We aimed to address this question by expressing a potato Sus gene in cotton where Sus expression has been previously shown to be critical for normal seed and fiber development. Segregation analyses at T1 generation followed by studies in homozygous progeny lines revealed that increased Sus activity in cotton （1） enhanced leaf expansion with the effect evident from young leaves emerging from shoot apex; （2） improved early seed development, which reduced seed abortion, hence enhanced seed set, and （3） promoted fiber elongation. In young leaves of Sus overexpressing lines, fructose concentrations were significantly increased whereas, in elongating fibers, both fructose and glucose levels were increased. Since hexoses contribute little to osmolality in leaves, in contrast to developing fibers, it is concluded that high Sus activity promotes leaf development independently of osmotic regulation, probably through sugar signaling. The analyses also showed that doubling the Sus activity in 0-d cotton seeds increased their fresh weight by about 30%. However, further increase in Sus activity did not lead to any further increase in seed weight, indicating an upper limit for the Sus overexpression effect. Finally, based on the observed additive effect on fiber yield from increased fiber length and seed number, a new strategy is proposed to increase cotton fiber yield by improving seed development as a whole, rather than solely focusing on manipulating fiber growth.

关键词： cotton fiber invertase leaf expansion seed abortion seed development sucrose synthase sugar signaling.

Optimizing laser coupling,matter heating,and particle acceleration from solids using multiplexed ultraintense lasers

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Matter and Radiation at Extremes 2024年第4期9卷 16-28页

作者： Weipeng Yao Motoaki Nakatsutsumi Sébastien Buffechoux Patrizio Antici Marco Borghesi Andrea Ciardi Sophia N.Chen Emmanuel d’Humières Laurent Gremillet robert Heathcote Voj.ech Horny Paul McKenna Mark N.Quinn Lorenzo Romagnani Ryan Royle Gianluca Sarri Yasuhiko Sentoku Hans-Peter Schlenvoigt Toma Toncian Olivier Tresca Laura Vassura Oswald Willi j.lien Fuchs LULI-CNRS CEASorbonne UniversitéEcole PolytechniqueInstitut Polytechnique de ParisF-91128 Palaiseau CedexFrance Sorbonne Université Observatoire de ParisUniversité PSLCNRSLERMAF-75005 ParisFrance INRS-EMT 1650 BoulLionel-BouletVarennesQuebec J3X 1S2Canada Center for Plasma Physics School of Mathematics and PhysicsQueen’s University BelfastBelfast BT71NNUnited Kingdom “Horia Hulubei”National Institute for Physics and Nuclear Engineering 30 Reactorului StreetRO-077125 Bucharest-MagureleRomania University of Bordeaux Centre Lasers Intenses et ApplicationsCNRSCEAUMR 5107F-33405 TalenceFrance CEA DAMDIFF-91297 ArpajonFrance Université Paris-Saclay CEALMCE91680 Bruyères-le-ChatelFrance Central Laser Facility STFC Rutherford Appleton LaboratoryDidcotUnited Kingdom SUPA Department of PhysicsUniversity of StrathclydeGlasgow G40NGUnited Kingdom Department of Physics University of NevadaRenoNevada 89557USA Institute of Laser Engineering Osaka University2-6 YamadaokaSuitaOsaka 565-0871Japan Institut fur Laser und Plasmaphysik Heinrich Heine Universitat DusseldorfDusseldorfGermany

Realizing the full potential of ultrahigh-intensity lasers for particle and radiation generation will require multi-beam arrangements due to technology ***,we investigate how to optimize their coupling with solid ***,we show that overlapping two intense lasers in a mirror-like configuration onto a solid with a large preplasma can greatly improve the generation of hot electrons at the target front and ion acceleration at the target *** underlying mechanisms are analyzed through multidimensional particle-in-cell simulations,revealing that the self-induced magnetic fields driven by the two laser beams at the target front are susceptible to reconnection,which is one possible mechanism to boost electron *** addition,the resistive magnetic field generated during the transport of the hot electrons in the target bulk tends to improve their *** simulations also indicate that such effects can be further enhanced by overlapping more than two laser beams.

关键词： laser acceleration particle

ON THE FINITE VOLUME ELEMENT VERSION OF RITZ-VOLTERRA PROj.CTION AND APPLICATIONS TO RELATED EQUATIONS

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j.urnal of Computational Mathematics 2002年第5期20卷 491-504页

作者： Tie Zhang Yan-ping Lin robert j.Tait Department of Mathematics Northeastern UniversityShenyang110004China Department of Mathematics University of AlbertaEdmontonAlbertaCanada

Presents a study that applied a general error analysis framework for the finite volume element (FVE) approximation to the Ritz-Volterra proj.ction, the Sobolev equations and parabolic integro-differential equations. Formulation of the FVE methods in linear finite element spaces defined on a triangulation; Information on the L[sub2] and H1 norm error estimates; Approximations to Sobolev equations and parabolic integro-differential equations.

关键词： finite volume element Ritz-Volterra proj.ction integro-differential equations error analysis

Ophiolites:Identification and tectonic significance in space and time

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Geoscience Frontiers 2023年第6期14卷 380-385页

作者： Kent C.Condie robert j.Stern Department of Earth&Environmental Science New Mexico Institute of Mining and TechnologySocorroNM 87801USA Geosciences Department University of Texas at DallasRichardsonTX 75080USA

Ophiolites are fragments of oceanic lithosphere that are produced at spreading centers at ocean ridges,back arc basins,or forearcs during subduction initiation,and are key indicators of plate *** it is widely agreed that ophiolites are remnants of oceanic crust and associated depleted mantle preserved in orogens,the recognition of ophiolites and their tectonic significance is still a topic of discussion and *** propose that ophiolites can be recognized in the geologic record by some combination of genetically related pillow basalt,layered gabbro,sheeted dykes,podiform chromite,harzburgite or/and *** igneous rocks have either ocean-ridge basalt or immature oceanic arc basalt chemical *** a scoring system of 1–11 for ophiolite confidence level,scores of8 are considered confident,6–8 probable,andj.rmua and Purtuniq ophiolites at 2000–1950 *** do not become geographically widespread until after 900 Ma,and most ophiolites of all ages formed in a forearc(subduction initiation)tectonic *** ophiolite production requires plate tectonics,subduction must have begun at least locally by 2700 Ma but did not become widespread until after 2000 *** abundance of ophiolites after 900 Ma may reflect better preservation of subduction-related ophiolites,or to an increasing global network of interconnected *** frequency peaks in the geologic record partially reflect geographic regions where ophiolites have been extensively studied rather than monitoring the production rate of ophiolites,but the scarcity of>900 Ma ophiolites is probably real.

关键词： Ophiolite Plate tectonics Subduction initiation Forearc Ocean ridge Tectonic setting Supercontinent

Stagnant lid tectonics:Perspectives from silicate planets,dwarf planets, large moons,and large asteroids

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Geoscience Frontiers 2018年第1期9卷 103-119页

作者： robert j.Stern Taras Gerya Paul j.Tackley Geosciences Department University of Texas at Dallas Department of Earth Sciences ETH-Zurich

To better understand Earth's present tectonic style-plate tectonics—and how it may have evolved from single plate(stagnant lid) tectonics, it is instructive to consider how common it is among similar bodies in the Solar System. Plate tectonics is a style of convection for an active planetoid where lid fragment(plate) motions reflect sinking of dense lithosphere in subduction zones, causing upwelling of asthenosphere at divergent plate boundaries and accompanied by focused upwellings, or mantle plumes;any other tectonic style is usefully called "stagnant lid" or "fragmented lid". In 2015 humanity completed a 50+ year effort to survey the 30 largest planets, asteroids, satellites, and inner Kuiper Belt obj.cts,which we informally call "planetoids" and use especially images of these bodies to infer their tectonic activity. The four largest planetoids are enveloped in gas and ice(j.piter, Saturn, Uranus, and Neptune)and are not considered. The other 26 planetoids range in mass over 5 orders of magnitude and in diameter over 2 orders of magnitude, from massive Earth down to tiny Proteus; these bodies also range widely in density, from 1000 to 5500 kg/m^3. A gap separates 8 silicate planetoids with ρ = 3000 kg/m^3 or greater from 20 icy planetoids(including the gaseous and icy giant planets) with ρ = 2200 kg/m^3 or less. We define the "Tectonic Activity Index"(TAI), scoring each body from 0 to 3 based on evidence for recent volcanism, deformation, and resurfacing(inferred from impact crater density). Nine planetoids with TAI = 2 or greater are interpreted to be tectonically and convectively active whereas 17 with TAI <2 are inferred to be tectonically dead. We further infer that active planetoids have lithospheres or icy shells overlying asthenosphere or water/weak ice. TAI of silicate(rocky) planetoids positively correlates with their inferred Rayleigh number. We conclude that some type of stagnant lid tectonics is the dominant mode of heat loss and that plate tectonics

关键词： Stagnant lid Solar system Plate tectonics Planets Moons

Atlas of minimally invasive thoracic surgery (VATS)

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Calibrated dilatometer exercise to probe thermoplastic properties of coal in pressurized CO2

2011年

作者： robert j. Mckenna j. Ali Mahtabifard Scott j. Swanson.

来源：畅想之星图书光盘版（南... 评论

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International j.urnal of Coal Science & Technology 2017年第3期4卷 245-251页

作者： Vyacheslav N. Romanov Ronald j. Lynn robert P. Warzinski U. S. Department of Energy National Energy TechnologyLaboratory P. O. Box 10940 Pittsburgh PA 15236 USA

This research was aimed at testing a hypothesis, that at elevated CO2 pressure coal can soften at temperatures well below those obtained in the presence of other gases. That could have serious negative implications for inj.ction of CO2 into deep coal seams. We have examined the experimental design issues and procedures used in the previously published studies, and experimentally investigated the physical behavior of a similar coal in the presence of COa as a function of pressure and temperature, using the same high-pressure micro-dilatometer refurbished and carefully calibrated for this purpose. No notable reduction in coal softening temperature was observed in this study.

关键词： Dilatometry · Carbon dioxide· Coal· Plasticization

Strain-induced band gap engineering in layered TiS3

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Nano Research 2018年第1期11卷 225-232页

作者： robert Biele Eduardo Flores j.se Ramon Ares Carlos Sanchez Isabel j. Ferrer Gabino Rubio-Bollinger Andres Castellanos-Gomezs roberto D'Agosta Nano-Bio Spectroscopy Group and European Theoretical Spectroscopy Facility (EFSF) Universidad del Pals Vasco 20018 San Sebastidn Spain Materials of Interest in Renewable Energies Group (MIRE Group) Dpto. de Fisica de Materiales Universidad Aut6noma de Madrid 28049 Madrid Spain Instituto de Ciencia de Materiales "Nicolds Cabrera" Campus de Cantoblanco 28049 Madrid Spain Dpto. de Ffsica de la Materia Condensada Condensed Matter Physics Center (IFIMAC) Universidad Aut6noma de Madrid Campus de Cantoblanco 28049 Madrid Spain Instituto de Ciencia de los Materiales de Madrid (ICMM-CSIC) Cantoblanco 28049 Madrid Spain IKERBASQUE Basque Foundation for Science 48013 Bilbao Spain

By combining ab initio calculations and experiments, we demonstrate how the band gap of the transition metal trichalcogenide TiS3 can be modified by inducing tensile or compressive strain. In addition, using our calculations, we predicted that the material would exhibit a transition from a direct to an indirect band gap upon application of a compressive strain in the direction of easy electrical transport. The ability to control the band gap and its nature could have a significant impact on the use of TiS3 for optical applications. We go on to verify our prediction via optical absorption experiments that demonstrate a band gap increase of up to 9% （from 0.99 to 1.08 eV） upon application of tensile stress along the easy transport direction.

关键词： band gap engineering titanium trisulfide 2-D materials strain