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Sol–gel La2O3–ZrO2 mixed oxide catalysts for biodiesel production

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journal of Energy Chemistry 2018年第2期27卷 565-572页

作者： Daniela Salinas Catherine Sepúlveda Néstor Escalona j.L.GFierro Gina Pecchi Departamento de Fisicoquimica. Facultad de Ciencias Quimicas Universidad de Concepcion Post Office 160-C Concepcion Chile Departamento de Quimica Facultad de Ciencias Universidad del Biobio Post Office 5-C Concepcion Chile Departamento Ingenieria Quimica y Bioprocesos Escuela de lngenieria Pontificia Universidad Catolica de Chile Avda. Vicuria Mackenna 4870 Maeul Santiago 7820436 Chile Centro de Investigacion en Nanotecnolagia y Materiales Avanzados (CIEN-UC) Pontificia Universidad Catolica de Chile Post Office 306 Santiago Chile Departamento de Quimica Fisica Facultad de Quimica Pontificia Universidad Catolica de Chile Post Offce 306 Santiago Chile Instituto de Catalisis y Petroleoquimica CSIC 28049 Madrid. Espana

Different La2O3 contents（0, 1, 2, 3, and 5 wt%） were used to prepared La2O3-ZrO2 mixed oxides calcined at 600 ℃ by the sol-gel method. The catalytic activity was measured as biodiesel production from canola oil through a transesterification reaction. The characterization results indicate that the La2O3 monolayer formation and extent of basicity of m-ZrO2 have a large influence on biodiesel *** biodiesel conversion（56% at 4 h） was obtained with the 3% La2O3-ZrO2 catalyst in the presence of basic sites and the formation of a monolayer of La2O3. The decrease in the catalytic activity for 5% La2O3-ZrO2 resulted from the loss of active sites on the catalyst because of agglomeration, which was suggested by XPS and the isoelectric point. The kinetic data fit to a pseudo-first order constant, and the largest kinetic constant corresponds to 3% La2O3-ZrO2, currently the largest heterogeneous non-alkaline metal catalyst reported for a transesterification reaction.

关键词： La2O3 -ZrO2 Sol-gel Biodiesel Canola oil Transesterification

Approximants in annealed IQC(Icosahedral Quasicrystal)-DQC(Decagonal Quasicrystal) pseudo-binary alloys

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中国有色金属学会会刊：英文版 2003年第6期13卷 1360-1366页

作者：雷奕 j.M.Dubois M.Calvo-Dahlborg 黑祖昆 P.Weisbecker 董闯 State Key Laboratory for Materials Modification LSG2M CNRS-UMR7584 Institute of Material & Technology

The structure and microstructure of constituent phases in annealed IQC100-xDQCx alloys, made from mixtures of (Al62Cu25.5Fe12.5) icosahedral quasicrystal （IQC） and (Al70Co15Ni15) decagonal quasicrystal （DQC）, were studied by X-ray diffractometry（XRD）, scanning electron microscopy （SEM）, and energy-dispersive X-ray spectroscopy （EDAX）. These constituent phases are mostly approximants: λ, β and τ3. In addition, an Al-Cu-Co DQC phase is observed in (IQC80DQC20) alloy. The nature of these approximants and their relationship with the quasicrystals（QCs） are discussed; and the evolution of these phases is interpreted by the shifting of their e/a-constant lines in the Al-（Cu, Ni）-（Fe, Co） pseudo-ternary phase diagrams.

关键词：二元合金准晶 IQC DQC 近似解退火相图

Spectroscopic investigations of Gd_3Sc_2Ga_3O_(12) garnet doped with Cr^(3+) and Nd^(3+) ions

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journal of Rare Earths 2009年第4期27卷 560-563页

作者： K.Lemański P.j.Dereń A.Gagor W.Strek Institute of Low Temperatures and Structure Research Polish Academy of Sciences

Absorption, excitation and emission spectra as well as decay time measurements at 10, 77, and 300 K were perfumed for Gd3Sc2Ga3O12 garnet single-crystal doped with Cr^3＋ and Nd^3＋ ions. Strong reabsorption of Cr3＋ emission by Nd3＋ absorption lines was ob- served. The assignments of f-f and d-d transitions were proposed. The broad emission band of chromium ions is an indication that weak/intermediate crystal field strength is present at the Cr3＋ site.

关键词： Gd3Sc2Ga3O12 crystal reabsorption Cr Nd rare earths

Simulating canopy stomatal conductance of winter wheat and its distribution using remote sensing information

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journal of Environmental Sciences 2001年第4期13卷 439-443页

作者： Zhang, j.-h. Fu, C.-b. Kanzawa, H. START Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

The canopy stomatal movement, a plant physiological process, generally occurs within leaves but its influence on exchange of CO2, water vapor, and sensible heat fluxes between atmosphere and terrestrial ecosystem. Many studies have documented that the interaction between leaf photosynthesis and canopy stomatal conductance is obvious. Thus, information on stomatal conductance is valuable in climate and ecosystem models. In current study, a newly developed model was adopted to calculate canopy stomatal conductance of winter wheat in Huang-Huai-Hai (H-H-H) Plain of China (31.5 - 42.7°N, 110.0 - 123.0°E). The remote sensing information from NOAA-AVHRR and meteorological observed data were used to estimate regional scale stomatal conductance distribution. Canopy stomatal conductance distribution pattern of winter wheat on March 18, 1997 was also presented. The developed canopy stomatal conductance model might be used to estimate canopy stomatal conductance in land surface schemes and seems can be acted as a boundary condition in regional climatic model runs.

关键词： Carbon dioxide Data reduction Ecosystems Heat flux Meteorology Photosynthesis Physiology Plants (botany) Remote sensing Vapors

Metamaterial-based graphene thermal emitter

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Nano Research 2018年第7期11卷 3567-3573页

作者： Cheng Shi Nathan H. Mahlmeister Isaac j. Luxmoore Geoffrey R. Nash College of Engineering Mathematics and PhysicaI Sciences University of Exeter Exeter EX4 4QF UK

A thermal emitter composed of a frequency-selective surface metamaterial layer and a hexagonal boron nitride-encapsulated graphene filament is demonstrated. The broadband thermal emission of the metamaterial （consisting of ring resonators） was tailored into two discrete bands, and the measured reflection and emission spectra agreed well with the simulation results. The high modulation frequencies that can be obtained in these devices, coupled with their operation in air, confirm their feasibility for use in applications such as gas sensing.

关键词： graphene hexagonal boron nitride thermal emitter infrared metamaterial

Batch equilibrium studies on the adsorptive capacity of powdered and pelleted maize tassel to remove PFOA and PFOS from aqueous medium

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Emerging Contaminants 2022年第1期8卷 75-82页

作者： Pinky Mokwena O.j.Okonkwo Department of Environmental Water and Earth SciencesFaculty of ScienceTshwane University of TechnologyPretoriaSouth Africa

This study was aimed at evaluating the potential of raw maize tassel powder and pellets to remove PFOA and PFOS from *** experiments were first conducted using ultrapure water to investigate the effects of pH,adsorbent dosage,initial PFASs concentration,contact time and temperature in adsorption efficiency of powdered and pelleted maize *** optimum conditions for the removal of PFOA/PFOS observed for both maize tassel powder and pellets were as follows:pH 2.0,adsorbate initial concentrations of 20 mg g1,adsorbent dosage of 0.5 g(20 pellets),1 h contact time,all at 25℃.These optimum conditions were,thereafter,applied to surface water samples from Apies River in Pretoria,spiked with 20 mg L^(-1)PFOS/*** LC-MS/MS was employed in analysis and the Langmuir and Freundlich isotherm models were used to determine the types of adsorption *** percentage removal 91.3%and 89.7%for PFOA and PFOS respectively using both MT powder and pellets were *** maximum adsorption capacities identified for the monolayer of the Langmuir isotherm model was found to be between 41.6 mg g^(-1)and 58.82 mg g^(-1)for PFOA using powder and pellets respectively;and between 42.37 mg g^(-1)and 176.5 mg g^(-1)for PFOS for the same adsorbents *** results showed very insignificant conformity to the Langmuir model;therefore it can be assumed that the Langmuir model was not ***,the experiments proved to be primarily consistent with the Freundlich model,with high correlation coefficient(R2)values ranging from 0.900 to 0.998 for both PFOA and *** adsorption capacities of 142.8 mg g^(-1)and 78.57 mg g^(-1)for PFOA and 107.4 mg g^(-1)and 85.7 mg g^(-1)for PFOS at 25℃using both powder and pellets respectively were obtained suggesting that adsorption took place on heterogeneous layers for both targeted PFASs.

关键词： Batch equilibrium Maize tassel PFASs Removal Aqueous medium

Gut microbiota metabolite regulation of host defenses at mucosal surfaces:implication in precision medicine

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Precision Clinical Medicine 2019年第2期2卷 110-119页

作者： Anthony j.Bilotta Yingzi Cong Department of Microbiology and Immunology University of Texas Medical BranchGalvestonTX 77555USA Department of Pathology University of Texas Medical BranchGalvestonTX 77555USA

The gut microbiota has a well-established role in the regulation of host *** factors control the composition and function of the *** westernization of diet,a shift away from nutrient-dense foods toward diets high in saturated fats,has been implicated in the rise of chronic inflammatory diseases such as inflammatory bowel disease(IBD).Diet is critical in the development and maintenance of a healthy microbiome,where dietary fiber(found in the highest amounts in fruits,vegetables,and legumes)is metabolized by the *** turn,the bacterial metabolites of dietary fiber,short chain fatty acids(SCFAs),regulate gut *** engage G-protein coupled receptors(GPRs)and act as histone deacetylase inhibitors(HDACi)to module epithelial and immune cell functions in the intestines,where they generally promote an anti-inflammatory *** review highlights the functions of SCFAs and their roles in the pathogenesis of IBD to provide insights into their potential therapeutic application for the treatment of IBD for the purposes of precision medicine.

关键词： microbiota metabolite host defense short chain fatty acids

Designing Hardware for the Boundary Condition Round Robin Challenge

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Sound & Vibration 2018年第1期52卷 9-12页

作者： David E.Soine Richard j.jones julie M.Harvie Troy j.Skousen Tyler F.Schoenherr Kansas City National Security Campus* 14520 Botts RoadKansas CityMissouriUSA Sandia National Laboratories P.O.Box 5800-MS 0840AlbuquerqueNM 87185

Qualification of products to their vibration and shock requirements in a laboratory setting consists of two basic *** first is the quantification of the product’s mechanical environment in the *** second is the process of testing the product in the laboratory to ensure it is robust enough to survive the field *** latter part is the subject of the“Boundary Condition for Component Qualification”challenge *** paper describes the challenges in determining the appropriate boundary conditions and input stimulus required to qualify the *** paper also describes the step sand analyses that were taken to design a set of hardware that demonstrates the issue and can be used by round robin challenge participants to investigate the problem.

关键词： field. Boundary Robin

ON APPROXIMATION OF A FUNCTION AND ITS DERIVATIVES BY A POLYNOMIAL AND ITS DERIVATIVES

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Analysis in Theory and Applications 1994年第3期10卷 93-103页

作者： T.Kilgore j.Szabados Aubunn University U.S.A Mathematical Institute of the Hungarian of Academy of Sciences. Hungaria

Let g∈C^q[-1, 1] be such that g^((k))(±1)=0 for k=0,…,q. Let P_n be an algebraic polynomial of degree at most n, such that P_n^((k))(±1)=0 for k=0,…,[_2~ (q+1)]. Then P_n and its derivatives P_n^((k)) for k≤q well approximate g and its respective derivatives, provided only that P_n well approxi- mates g itself in the weighted norm ‖g(x)-P_n(x) (1-x^2)^(1/2)~q‖ This result is easily extended to an arbitrary f∈C^q[-1, 1], by subtracting from f the polynomial of minnimal degree which interpolates f^((0))…,f^((q)) at±1. As well as providing easy criteria for judging the simultaneous approximation properties of a given Polynomial to a given function, our results further explain the similarities and differences between algebraic polynomial approximation in C^q[-1, 1] and trigonometric polynomial approximation in the space of q times differentiable 2π-periodic functions. Our proofs are elementary and basic in character, permitting the construction of actual error estimates for simultaneous approximation proedures for small values of q.

关键词： ON APPROXIMATION OF A FUNCTION AND ITS DERIVATIVES BY A POLYNOMIAL AND ITS DERIVATIVES ITS