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Visualizing the importance of oxide-metal phase transitions in the production of synthesis gas over Ni catalysts

Journal of Energy chemistry 2020年第11期29卷 178-186页

作者： luis Sandoval-Diaz Milivoj Plodinec Danail Ivanov Stephane Poitel Adnan Hammud Hannah c.Nerl Robert Schldgl Thomas Lunkenbein Department of Inorganic chemistry Fritz-Haber-Institut der Max-Planck-GesellschaftFaradayweg 4-614195 BerlinGermany Electron Spectrometry and Microscopy Laboratory School of Basic SciencesEcole Polytechnique Federale de Lausanne1015 LausanneSwitzerland Max Planck Institute for chemical Energy conversion StiftstraJSe 34-3645470 Miihlheim a.d.RuhrGermany

Synthesis gas, composed of H2 and cO, is an important fuel which serves as feedstock for industrially relevant processes, such as methanol or ammonia synthesis. The efficiency of these reactions depends on the H2: cO ratio, which can be controlled by a careful choice of reactants and catalyst surface ***, using a combination of environmental scanning electron microscopy(ESEM) and online mass spectrometry, direct visualization of the surface chemistry of a Ni catalyst during the production of synthesis gas was achieved for the first time. The insertion of a homebuilt quartz tube reactor in the modified ESEM chamber was key to success of the setup. The nature of chemical dynamics was revealed in the form of reversible oxide-metal phase transitions and surface transformations which occurred on the performing catalyst. The oxide-metal phase transitions were found to control the production of synthesis gas in the temperature regime between 700 and 900 ℃ in an atmosphere relevant for dry reforming of methane(DRM, cO2: cH4=0.75). This was confirmed using high resolution transmission electron microscopy imaging, electron energy loss spectroscopy, thermal analysis, and c18O2 labelled *** dedicated operando approach of simultaneously studying the surface processes of a catalyst and its activity allowed to uncover how phase transitions can steer catalytic reactions.

关键词： Dry reforming of methane Partial oxidation of methane Environmental scanning electron microscopy Synthesis gas Operando

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Assembly of IMPDH2-Based,cTPS-Based,and Mixed Rod/Ring Structures Is Dependent on cell Type and conditions of Induction

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Journal of Genetics and Genomics 2015年第6期42卷 287-299页

作者： Gerson Dierley Keppeke S.John calise Edward K.L.chan luis Eduardo c.Andrade Rheumatology Division Federal University of Sao Paulo Department of Oral Biology University of Florida Immunology Division Fleury Medicine and Health Laboratories

Inhibition of guanosine triphosphate（GTP） and cytidine triphosphate（cTP） biosynthetic pathways induces cells to assemble rod/ring（RR） structures,also named cytoophidia,which consist of the enzymes cytidine triphosphate synthase（cTPS） and inosine-50-monophosphate dehydrogenase 2（IMPDH2）.We aim to explore the interaction of cTPS and IMPDH2 in the generation of RR *** La and cOS-7 cells were cultured in normal conditions or in the presence of 6-diazo-5-oxo-L-norleucine（DON）,ribavirin,or mycophenolic acid（MPA）.Over 90% of DON-treated cells presented RR *** He La cells,35% of the RR structures were positive for IMPDH2 alone,26% were cTPS alone,and 31% were IMPDH2/cTPS mixed,while in cOS-7 cells,42% of RR were IMPDH2 alone,41% were cTPS alone,and 10% were IMPDH2/cTPS *** and MPA treatments induced only IMPDH2-based *** were also transfected with an N-terminal hemagglutinin（NHA）-tagged cTPS1 *** 95% of NHA-cTPS1 transfected cells with DON treatment presented IMPDH2-based RR and almost 100% presented cTPS1-based RR;when treated with ribavirin,over 94% of transfected cells presented IMPDH2-based RR and 37% presented cTPS1-based RR,whereas 2% of untreated transfected cells presented IMPDH2-based RR and 28% presented cTPS1-based *** results may help in understanding the relationship between cTP and GTP biosynthetic pathways,especially concerning the formation of filamentous RR structures.

关键词： Nucleotide synthesis Enzyme aggregation Enzyme inhibition IMPDH2 cTPS

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Numerical Methods for Solving the Hartree-Fock Equations of Diatomic Molecules I

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communications in computational Physics 2009年第5期5卷 959-985页

作者： John c.Morrison Scott Boyd luis Marsano Bernard Bialecki Thomas Ericsson Jose Paulo Santos Department of Physics University of LouisvilleLouisvilleKY40292USA Department of Mathematical and computer Sciences Colorado School of MinesGoldenCO 80401-1887USA Department of Mathematical Sciences Chalmers University of Technology and the University of GothenburgSE-41296 GothenburgSweden Department of Physics New University of LisbonLisbonPortugal

The theory of domain decomposition is described and used to divide the variable domain of a diatomic molecule into separate regions which are solved *** approach makes it possible to use fast Krylov methods in the broad interior of the region while using explicit methods such as Gaussian elimination on the *** is demonstrated by solving a number of model problems,these methods enable one to obtain solutions of the relevant partial differential equations and eigenvalue equations accurate to six significant figures with a small amount of computational *** the numerical approach described in this article decomposes the variable space into separate regions where the equations are solved independently,our approach is very well-suited to parallel computing and offers the long term possibility of studying complex molecules by dividing them into smaller fragments that are calculated separately.

关键词： Fast Krylov methods splines Hartree-Fock equations diatomic molecules eigenvalue problem

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Steroid-responsive pancreatitides

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World Journal of clinical cases 2020年第16期8卷 3411-3430页

作者： Mario Pelaez-Luna Andrea Soriano-Rios Ana c Lira-Treviño luis Uscanga-Domínguez Department of Gastroenterology National Institute of Medical Sciences and Nutrition"Salvador Zubiran"Mexico City 14000Mexico

Autoimmune pancreatitis has received considerable attention,especially due to the marked effect of corticosteroid therapy on its clinical ***,especially regarding type 1 autoimmune pancreatitis,has significantly increased over the last decades,and despite significant differences in pathophysiology and outcomes,both type 1 and 2 autoimmune pancreatitis are still considered different types of the same *** have proposed a different nomenclature reflecting these *** the term steroid-responsive pancreatitides may be interpreted as synonymous to type 1 and 2 autoimmune pancreatitis,these are not the only pancreatic conditions that show a response to steroid *** pancreatitis caused by vasculitis and connective tissue diseases and acute pancreatitis secondary to checkpoint inhibitors or programmed cell death receptor antibody-mediated blockage cancer therapy may also benefit from steroid *** review presents current concepts on these disorders,aiming to increase awareness,analyze similarities and differences,and propose a new nomenclature that reflects their specific particularities,clustering them under the term"steroid-responsive pancreatitides".

关键词： Autoimmune pancreatitis Lymphoplasmacytic sclerosing pancreatitis Idiopathic duct centric chronic pancreatitis Vasculitis Immune checkpoint inhibitors corticosteroids

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A Data Security Framework for cloud computing Services

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computer Systems Science & Engineering 2021年第5期37卷 203-218页

作者： luis-Eduardo Bautista-Villalpando Alain Abran Department of Electronic Systems Autonomous University of AguascalientesAguascalientes20131Mexico Department of Software Engineering and Information Technology ETSUniversity of QuebecMontrealH3C 1K3Canada

cyberattacks are difficult to prevent because the targeted companies and organizations are often relying on new and fundamentally insecure cloudbased technologies,such as the Internet of *** increasing industry adoption and migration of traditional computing services to the cloud,one of the main challenges in cybersecurity is to provide mechanisms to secure these *** work proposes a Data Security Framework for cloud computing services(ccS)that evaluates and improves ccS data security from a software engineering perspective by evaluating the levels of security within the cloud computing paradigm using engineering methods and techniques applied to *** framework is developed by means of a methodology based on a heuristic theory that incorporates knowledge generated by existing works as well as the experience of their *** paper presents the design details of the framework,which consists of three stages:identification of data security requirements,management of data security risks and evaluation of data security performance in ccS.

关键词： cloud computing services computer security data security data security requirements data risk data security measurement

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Growth mechanism of octahedron-like BaMoO_4 microcrystals processed in microwave-hydrothermal:Experimental observations and computational modeling

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Particuology 2009年第5期7卷 353-362页

作者： Laécio Santos cavalcante Júlio césar Sczancoski Rircado luis Tranquilin José Arana Varela Elson Longo Marcelo Ornaghi Orlandi Departamento de Química UFSCarP.O. Box 67613565-905So CarlosSPBrazil Instituto de Química-UNESP P.O. Box 35514801-907AraraquaraSPBrazil

Octahedron-like BaMoO4 microcrystals were synthesized by the co-precipitation method at room temperature and processed in microwave-hydrothermal at 413 K for different times （from 30 min to 5 h）. These microcrystals were analyzed by X-ray diffraction （XRD）, field-emission gun scanning electron microscopy （FEG-SEM） and transmission electron microscopy （TEM）. XRD patterns showed that this material presents a tetragonal structure without the presence of deleterious phases. FEG-SEM and TEM micrographs revealed that the BaMoO4 microcrystals present an octahedron-like morphology with agglomerate nature and polydisperse particle size distribution. These micrographs also indicated that the microcrystals grow along the [0 01 ] direction. The observed crystallographic planes in these structures were modeled computationally and a crystal growth model was proposed in order to explain the morphological changes as a function of processing time.

关键词： BaMoO4 Growth process Microwave-hydrotherma Supersaturated solution

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Development of Junction Elements from Study of the Bionics

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Journal of Bionic Engineering 2007年第1期4卷 41-46页

作者： Wilson Kindlein Junior luis Henrique Alves cndido André canal Marques Sandra Souza dos Santos Maurício da Silva Viegas Laboratory of Design and Material Selection-LdSM-Materials Department (DEMAT) School of Engineering–EE Federal University of Rio Grande do Sul-Brazil-UFRGS Brazil

The applications of bionic methodology developed by the Laboratory of Design and Material Selection as basis in the creation of junction elements were demonstrated. These elements favor the application of Ecodesign in reference to the effectiveness of product dismount aiming the reduction of ambient impact in all its phases of use. The creation, the development and the confection of new junction elements were described, and case studies of new products developed specifically with this purpose were presented.

关键词： bionics Ecodesign junction elements

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Treatability studies of naphthalene in soil,water and air with persulfate activated by iron(Ⅱ)

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Journal of Environmental Sciences 2020年第4期32卷 67-77页

作者： Gabriela P.mendes Vivian M.A.Magalhaes Lélia c·R·Soares Rayanne M.Aranha c.audio A.O.Nascimento Marilda M.G.R.Vianna Osvaldo chiavone-Filho Department of chemical Engineering University of Sao PauloSPf 05508-000Brazil Department of chemical Engineering Federal University of Rio Grande Do NorteNatalRN59072-970Brazil

chemical oxidation was applied to an artificially contaminated soil with naphthalene(NAP).Evaluation of NAP distribution and mass reduction in soil,water and air phases was carried out through mass *** of NAP distribution and mass reduction in soil,water and air phases was carried out through mass *** importance of the air phase analysis was emphasized by demonstrating how NAP behaves in a sealed system over a 4 hr reaction *** of Experiments method was applied to the following variables:sodium persulfate concentration[SP],ferrous sulfate concentration[FeS04],and *** system operated with a prefixed solid to liquid ratio of 1:*** following conditions resulted in optimum NAP removal[SP]=18.37 g/L,[FeSO4]=4.25 g/L and pH=*** the end of the 4 hr reaction,62%of NAP was *** the soil phase,the chemical oxidation reduced the NAP concentration thus achieving levels which comply with Brazilian and USA environmental *** the NAP partitioning view,the monitoring of each phase allowed the variabilities assessment over the process,refining the knowledge of mass *** on NAP distribution in the system,this study demonstrates the importance of evaluating the presence of semi-volatile and volatile organic compounds in the air phase during remediation,so that there is greater control of the system as to the distribution and presence of the contaminant in the *** results highlight the importance of treating the contaminant in all its phases at the contaminated site.

关键词： chemical oxidation Phase distribution Degradation kinetics PAH Soil remediation Mass balance

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Black holes in asymptotic safety with higher derivatives:accretion and stability analysis

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chinese Physics c 2021年第7期45卷 293-304页

作者： Fabian H.Zuluaga luis A.Sanchez Escuela de Fisica Universidad Nacional de ColombiaA.A.3840MedellinColombia

We review steady spherically symmetric accretion onto a renormalization group improved Schwarzschild space-time,which is a solution to an asymptotically safe theory(AS)containing high-derivative *** use a Hamiltonian dynamical system approach for the analysis of the accretion of four types of isothermal test fluids:ultra-stiff fluid,ultra-relativistic fluid,radiation fluid,and sub-relativistic *** important outcome of our study is that,contrary to the claim in a recent work,there are physical solutions for the accretion of an ultra-relativistic fluid in AS,which include subsonic,supersonic,and transonic ***,we study quantum corrections to the known stability of the accretion in general relativity(GR).To this end,we use a perturbative procedure based on the continuity equation with the mass accretion rate being the perturbed *** classes of perturbations are studied:standing and traveling *** find that quantum gravity effects either enhance or diminish the stability of the accretion depending on the type of test fluid and the radial distance to the central object.

关键词： asymptotic safety black holes accretion stability

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Occurrence data may provide unreliable thermal preferences and breadth of species

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current Zoology 2015年第6期61卷 972-982页

作者： Sara VILLEN-PEREZ luis M. cARRAScAL Department of Biogeography and Global change National Museum of Natural Sciences MNCN-CSIC. C/José Gutiérrez Abascal 2 28006 Madrid Spain.

Accurate information on the thermal preference and specialization of species is needed to understand and predict spe- cies geographical range size and vulnerability to climate change. Here we estimate the position and breadth of species within thermal gradients based on the shape of the response curve of species abundance to temperature. The objective of the study is to compare the measurements of this approach based on abundance data with those of the classical approach using species＇ occur- rence data. The relationship between species＇ relative abundance and minimum winter temperature of 106 bird species wintering in the Iberian Peninsula is modeled at 100 Km2 resolution with quadratic logistic regressions. From these models we calculated the preferred temperature of species as the temperature at which the abundance is maximized, and the thermal breadth of species as the relative area under the temperature-abundance curve. We also estimated the thermal preferences and breadth of species as the average temperature and temperature range of the UTM cells in which the species are present. The abundance-temperature response curves reveal that birds prefer higher temperatures to overwinter, and are more thermally selective, than is measured by the classical approach. Moreover, response curves detect a higher inter-specific variability in both thermal preferences and ther- mal breadth of species. As occurrence data gives the same weight to cells with one or many individuals, the average temperature of the cells in which the species is present roughly reflects the average temperature in the region of study and not the environ- mental preferences of species .

关键词： Abundance-temperature response curve Birds Species occurrence Thermal breadth Thermal preferences Winter

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