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STUDIES ON SYNTHESIS, STRUCTURE AND REACTIVITY OF ACTIVATED Os_6 RAFT-LIKE CLUSTERS

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Science China Chemistry 1990年第4期33卷 385-392页

作者：刘家础 b.F.G.johnson J.LEWIS Fujian Institute of Research on the Structure of Matter Academia Sinica Fuzhou 350002PRC University Chemical Laboratory Lensfield Road Cambridge CB2 1EW U K

In this paper we report the synthesis and activation of OS-6 raft-llke planar clusters. The activated OS-66 raft-like clusters [OS-66(CO)_(20)(MeCN)] and [OS-66(CO)_(19) (MeCN)_2] have been prepared by involving PdCl_2 as catalyst. Trimethylamine oxide (Me_3NO) has been used as an activation reagent to oxidize several carbonyl ligands coordinated in the activated clusters and to get a series of activated OS-66 raft-like clusters [OS-66(CO)_(21-x)(MeCN)_x] (n = 1--5) and corresponding substituted clusters [OS-66(CO)_(21-x)(P(OMe)_3)_x] (n=1--5). The structures of these OS-66 raft-like clusters have been characterized by the infrared spectra (IR), nuclear magnetic resonance spectra (NMR) and mass spectra (MS), and the characters of the raft-like planar structure and reactivity above have also been discussed in this paper.

关键词： Os raft-like clusters coupling reaction aetivation.

Design of refractory multi-principal-element alloys for high-temperature applications

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npj Computational Materials 2023年第1期9卷 884-893页

作者： Gaoyuan Ouyang Prashant Singh Ranran Su Duane D.johnson matthew J.Kramer John H.Perepezko Oleg N.Senkov Daniel Miracle Jun Cui Division of Materials Science and Engineering Ames LaboratoryAmesIA 50011USA Department of Materials Science and Engineering University of Wisconsin-MadisonMadisonWI 53706USA Department of Materials Science and Engineering Iowa State UniversityAmesIA 50011USA Air Force Research Laboratory Materials and Manufacturing DirectorateWright-Patterson Air Force BaseDaytonOH 45433USA

Refractory multi-principal-element alloys(RMPEAs)exhibit high specific strength at elevated temperatures(T).However,current RMPEAs lack a balance of room-temperature(RT)ductility,high-T strength,and high-T creep *** density-functional theory methods,we scanned composition space using four criteria:(1)formation energies for operational stability:-150250 GPa;(3)inverse Pugh ratio for ductility:G/b2500°*** rapid bulk alloy synthesis and characterization,we validated theory and down-selected promising alloy compositions and discovered Mo72.3W12.8Ta10.0Ti2.5Zr2.5 having well-balanced RT and high-T mechanical *** alloy has comparable high-T compressive strength to well-known MoNbTaW but is more ductile and more creep *** is also superior to a commercial Mo-based refractory alloy and a nickel-based superalloy(Haynes-282)with improved high-T tensile strength and creep resistance.

关键词： creep alloy alloys

boldness and predator evasion in naturally hybridizing swordtails （Teleostei： Xiphophorus）

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Current Zoology 2015年第4期61卷 596-603页

作者： James b. johnson Zachary W. CULUMbER Ryan EASTERLING Gil G. R.OSENTHAL Department of biology Texas A&M University College Station Texas TX 77843 USA Centro de lnvestigaciones Cientificas de las Huastecas "Aguazarca" Calnali Hidalgo Mexico

Correlations among behavioral traits can generate trade-offs and constrain phenotypic evolution. Interspecific hybridization has the potential to alter behavioral trait correlations, but the effect of hybridization on suites of behavioral traits has received relatively little attention. We evaluated how natural hybridization changes the relationship between boldness （time of emergence and proportion of time out of shelter） and response to a simulated predator threat in swordtails （Teleostei： Xiphophorus）. In poeciliid fishes, bold individuals have increased survival in the presence of predators. This non-intuitive observation may arise as a result of bold individuals being more likely to engage in anti-predator behaviors. Contrary to our prediction, bold indi- viduals were less likely to perform a fast-start response to a predator threat. This correlation was consistent among populations and species but was only significant in hybrids. The observed correlation between boldness and anti-predator behavior could im- pact hybrid fitness and the evolvability of hybrid lineages. More generally, our findings suggest that hybridization could influence the integration of behavioral phenotypes, as has been amply documented for morphology. Animal personality and behavioral syndromes could therefore play an important role in the evolutionary fate of natural hybrids [Current Zoology 61 （4）： 596-603, 2015].

关键词： Trait compensation Fast-Start Anti-predator behavior hybridization behavioral syndrome Animal personality

Quantifying relations between altered hydrology and fish community responses for streams in Minnesota

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Ecological Processes 2022年第1期11卷 536-560页

作者： Jeffrey R.Ziegeweid Gregory D.johnson Aliesha L.Krall Kara Fitzpatrick Sara b.Levin U.S.Geological Survey California Water Science Center6000 J StPlacer HallSacramentoCA 85819USA U.S.Geological Survey Upper Midwest Water Science Center2280 Woodale DrMounds ViewMN 55112USA Minnesota Pollution Control Agency 520 Lafayette RdSt.PaulMN 55155USA Minnesota Pollution Control Agency 7678 College RoadSuite 105BaxterMN 56425USA

background:Altered hydrology is a stressor on aquatic life,but quantitative relations between specific aspects of streamflow alteration and biological responses have not been developed on a statewide scale in *** sub-sets regression analysis was used to develop linear regression models that quantify relations among five categories of hydrologic metrics(i.e.,duration,frequency,magnitude,rate-of-change,and timing)computed from streamgage records and six categories of biological metrics(i.e.,composition,habitat,life history,reproductive,tolerance,trophic)computed from fish-community samples,as well as fish-based indices of biotic integrity(FIbI)scores and FIbI scores normalized to an impairment threshold of the corresponding stream class(FIbI_bCG4).Relations between hydrology and fish community responses were examined using three hydrologic datasets that represented periods of record,long-term changes,and short-term changes to flow regimes in streams of ***:Regression models demonstrated significant relations between hydrologic explanatory metrics and fish-based biological response metrics,and the five regression models with the strongest linear relations explained over 70%of the variability in the biological metric using three hydrologic metrics as explanatory ***-based biological metrics demonstrated the strongest linear relations to hydrologic *** most commonly used hydrologic metrics were related to bankfull flows and aspects of flow ***:Final regression models represent paired streamgage records and biological samples throughout the State of Minnesota and encompass differences in stream orders,hydrologic landscape units,and watershed *** methods can support evaluations of stream fish communities and facilitate targeted efforts to improve the health of fish *** also can be applied to locations outside of Minnesota with continuous streamgage data and fish-community sampl

关键词： EflowStats best subset regression Altered hydrology Fish community Indices of biotic integrity Ecological flows

China＇s iGeneration： Cinema and Moving Image Culture for the Twenty-First Century

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Frontiers of Literary Studies in China-Selected Publications from Chinese Universities 2017年第2期11卷 407-414页

作者： johnson, matthew D. Keith b. Wagner Tianqi Yu Luke Vulpiania Hui Faye Xiao 不详 University of Kansas

China has become the largest film market outside Hollywood. The new millennium has witnessed manifold changes in this arena： the record-breaking box office boom; the fast-growing number of screens and multiplex theaters; the decreasing average age of moviegoers; the constant transmedial movement from online fiction to film and other popular media products; the proliferation of video streaming websites; and the widespread use of digital technologies and portable screens in various sizes （including laptops, tablets, smartphones, iPods）. All of these have dramatically changed the viewing platforms, habits, patterns, and pleasures of the younger generation of film audiences, which in turn has shaped the means of film production, distribution, and exhibition.

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A classical equation that accounts for observations of non-Arrhenius and cryogenic grain boundary migration

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npj Computational Materials 2022年第1期8卷 1492-1500页

作者： Eric R.Homer Oliver K.johnson Darcey britton James E.Patterson Eric T.Sevy Gregory b.Thompson Department of Mechanical Engineering Brigham Young UniversityProvoUT84602USA Department of Chemistry and biochemistry Brigham Young UniversityProvoUT84602USA Department of Metallurgical and Materials Engineering University of AlabamaTuscaloosaAL35401USA

Observations of microstructural coarsening at cryogenic temperatures,as well as numerous simulations of grain boundary motion that show faster migration at low temperature than at high temperature,have been troubling because they do not follow the expected Arrhenius *** work demonstrates that classical equations,that are not simplified,account for all these oddities and demonstrate that non-Arrhenius behavior can emerge from thermally activated *** to this classical model,this occurs when the intrinsic barrier energies of the processes become small,allowing activation at cryogenic *** thermal energy then allows the low energy process to proceed in reverse,so increasing temperature only serves to frustrate the forward *** classical form is shown to reconcile and describe a variety of diverse grain boundary migration observations.

关键词： cryogenic grain boundary

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人源性流行性出血热病毒的形态特征

病毒学杂志 1991年第2期6卷 129-131页

作者：杨占秋向近敏肖书渊张天明郑志明 P.P.Liberski b.johnson J.C.Gibbs.gr 湖北医学院病毒研究所武汉430071 NIH NINCDS中枢神经研究室

本文报道流行性出血热病毒(汉坦病毒)H-114株的电镜形态。发现形态发生以内质网膜和胞浆膜芽生为主。病毒颗粒为圆形或卵圆形。具有双层膜结构,大小为90～120nm。提出了汉坦病毒形态发生的理论观点。

关键词：流行性出血热病毒形态特征

Continental island from the Upper Silurian (Ludlow) Sino-Korean plate

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Chinese Science bulletin 2001年第3期46卷 238-241页

作者： RONG Jiayu M.E.johnson b.G.baarli LI Wenguo SU Wenbo WANG Jian Nanjing Institute of Geology and Palaeontology Chinese Academy of SciencesNanjing 210008China Geosciences Department Williams CollegeWilliamstownMassachusetts 01267USA Inner Mongolian Geological Survey Hohhot 010010China Department of Geology Chinese University of GeologyBeijing 100083China

Recent field studies on Upper Silurian stratigraphy and paleontology in the Inner Mongolia Autonomous Region (for short Inner Mongalia) near bater Obo (=bateaobao) resulted in the discovery of a small continental island with fossil invertebrates preserved as encrusters (stromatoporoids and corals) attached directly to a rocky shore surface and buried by silty clay mud. The bater island (named herein) is 610 m ×200 m in size and composed of Ordovician igneous rock (diorite). Limestone strata dating from the Ludlow Epoch (about 420 Ma) surround the island and dip away from the igneous core in a radial pattern. The encrusting fossils occur on the sheltered (south and southeast) side of the island, whereas the north side was exposed to stronger wave activity based on a basal conglomerate unit composed of diorite boulders. This is the first record of an ancient island in China and the first report worldwide of stromatoporoids as members of a rocky-shore community. The island clearly shows distinct windward

关键词： Silurian island Sino-Korean plate rocky shores encrusting biota

Effects of TiC addition on properties of laser particle deposited WC-Co-Cr and WC-Ni coatings

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Transactions of Nonferrous Metals Society of China 2013年第12期23卷 3634-3642页

作者： b.A.ObADELE P.A.OLUbAMbI O.T.johnson Department of Chemical Metallurgical and Materials Engineering Tshwane University of Technology

The mechanisms by which titanium carbide （TiC） improves the properties of tungsten carbide （WC） coatings deposited on duplex stainless steels using laser particle injection technique were investigated. The relationships between laser process parameters and the synthesized composite were studied. The morphologies and microstructures of the feedstock powders and composite coatings were characterized using scanning electron microscopy （SEM） and energy dispersive X-ray spectroscopy （EDX） techniques. Surface hardness of the composite layers was determined using the Vickers microhardness tester while its corrosion behaviour in 3.5%NaCl solution was investigated by potentiodynamic polarization curve measurement method. As a result of the laser treatment, microstructures characterized by hard ceramic particles with strong bonding to substrate were formed on the surface layer of the steels. The addition of TiC to WC resulted in microstructures free from cracks, pores and intermetallics which could be detrimental to the properties of the composites. High microhardness was observed and most of the coatings shifted the corrosion potential to more noble values with the pseudo-passive curve.

关键词： laser particle injection titanium carbide tungsten carbide corrosion behaviour hardness