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Displacement Current in Domain Walls of Bismuth Ferrite

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npj Computational Materials 2018年第1期4卷 597-605页

作者： Sergey Prosandeev Yurong Yang charles Paillard L.Bellaiche Physics Department and Institute for Nanoscience and Engineering University of ArkansasFayettevilleAR 72701USA Institute of Physics and Physics Department of Southern Federal UniversityRostov-na-Donu 344090Russia

In 1861,Maxwell conceived the idea of the displacement current,which then made laws of electrodynamics more complete and also resulted in the realization of devices exploiting such displacement ***,it is presently unknown if such displacement current can result in large intrinsic ac current in ferroic systems possessing domains,despite the flurry of recent activities that have been devoted to domains and their corresponding conductivity in these ***,we report firstprinciples-based atomistic simulations that predict that the transverse(polarization-related)displacement currents of 71°and 109°domains in the prototypical BiFeO_(3) multiferroic material are significant at the walls of such domains and in the GHz regime,and,in fact,result in currents that are at least of the same order of magnitude than previously reported dc currents(that are likely extrinsic in nature and due to electrons).Such large,localized and intrinsic ac currents are found to originate from low-frequency vibrations at the domain walls,and may open the door to the design of novel devices functioning in the GHz or THz range and in which currents would be confined within the domain wall.

关键词： currents regime magnitude

Flavonoids:New Roles for Old Molecules

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Journal of Integrative Plant Biology 2010年第1期52卷 98-111页

作者： charles S. Buer Nijat Imin Michael A. Djordjevic Genomic Interactions Group ARC Centre of Excellence for Integrative Legume Research Research School of Biology College of Medicine Biology and Environment The Australian National University

Flavonoids are ubiquitous in the plant kingdom and have many diverse functions including defense, UV protection, auxin transport inhibition, allelopathy, and flower coloring. Interestingly, these compounds also have considerable biological activity in plant, animal and bacterial systems - such broad activity is accomplished by few compounds. Yet, for all the research over the last three decades, many of the cellular targets of these secondary metabolites are unknown. The many mutants available in model plant species such as Arabidopsis thaliana and Medicago truncatula are enabling the intricacies of the physiology of these compounds to be deduced. In the present review, we cover recent advances in flavonoid research, discuss deficiencies in our understanding of the physiological processes, and suggest approaches to identify the cellular targets of flavonoids.

关键词： Flavonoids DPBA Figure TTG root

Mechanical properties of coppiced and non-coppiced Pterocarpus erinaceus boles and their industrial application

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Journal of Forestry Research 2019年第5期30卷 1973-1980页

作者： charles Antwi-Boasiako Frederick Amin Anthonio Kwasi Frimpong-Mensah Kwame Nkrumah University of Science and Technology

Rosewood(Pterocarpus erinaceus Poir.)is valued for flooring,ornaments,musical instruments and furniture-making due to its durability,strength,beauty and acoustic *** coppices easily which could boost its continual *** parallel to grain,Modulus of Elasticity(MOE)and Modulus of Rupture(MOR)within coppiced and non-coppiced boles were *** properties decreased along both types of *** values for the heartwood were also greater than those for the sapwood of each type of ***,MOR and compression for non-coppiced stems were greater than those from the coppiced *** differences were significant(p<0.05).Mechanical properties from the coppiced and non-coppiced boles are *** have strength properties comparable with those of species widely used for railway sleepers,structural supports,flooring,veneer,furniture,cabinetry,truss and mine ***,coppiced wood could supplement non-coppiced wood for industrial applications which require strength.

关键词： Coppicing Wood density Mechanical property Rosewood Structural application

Data-driven Bayesian model-based prediction of fatigue crack nucleation in Ni-based superalloys

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npj Computational Materials 2022年第1期8卷 354-368页

作者： Maxwell Pinz George Weber Jean charles Stinville Tresa Pollock Somnath Ghosh Civil&Systems Engineering Johns Hopkins UniversityBaltimoreMD21218USA Materials Department University of CaliforniaSanta BarbaraCA93106USA Departments of Civil&Systems Engineering Mechanical Engineeringand Materials Science&EngineeringJohns Hopkins UniversityBaltimoreMD21218USA

This paper develops a Bayesian inference-based probabilistic crack nucleation model for the Ni-based superalloy René88DT under fatigue loading.A data-driven,machine learning approach is developed,identifying underlying mechanisms driving crack *** experimental set of fatigue-loaded microstructures is characterized near crack nucleation sites using scanning electron microscopy and electron backscatter diffraction images for correlating the grain morphology and crystallography to the location of crack nucleation sites.A concurrent multiscale model,embedding experimental polycrystalline microstructural representative volume elements(RVEs)in a homogenized material,is developed for fatigue *** RVE domain is modeled by a crystal plasticity finite element *** anisotropic continuum plasticity model,obtained by homogenization of the crystal plasticity model,is used for the exterior domain.A Bayesian classification method is introduced to optimally select informative state variable predictors of crack *** this principal set of state variables,a simple scalar crack nucleation indicator is formulated.

关键词： crack fatigue superalloy

Roles of the main olfactory and vomeronasal systems in the detection of androstenone in inbred strains of mice

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Current Zoology 2010年第6期56卷 813-818页

作者： Vera V. VOZNESSENSKAYA Maria A. KLYUCHNIKOVA charles J. WYSOCKI A.N. Severtzov Institute of Ecology & Evolution RAS Monell Chemical Senses Center

We investigated the role of the main olfactory and accessory olfactory systems （MOS and AOS respectively） in the detection of androstenone. We used the following experimental approaches： behavioral, surgical removal of the vomeronasal organ （VNX） followed by histochemical verification and Fos immunohistochemistry. Using a Y-maze paradigm we estimated sensitivity of NZB/B1NJ and CBA/J mice to androstenone. CBA mice were 2,000-fold more sensitive to androstenone than NZB mice. VNX caused a 4-tol6-fold decrease in sensitivity to androstenone in highly-sensitive CBA mice, but did not affect thresholds in NZB mice. Results indicate the involvement of the MOS and AOS in the detection of androstenone. We observed a specific pattern of Fos-positive cells in the main olfactory bulb of CBA mice but not in NZB mice subsequent to exposure of mice to androstenone; the compound activated cells in the accessory olfactory bulb in both strains of mice, indicating the involvement of the vomeronasal organ. Patterns of Fos-positive cells in the vomeronasal organ were recorded subsequent to exposure to androstenone. Fos-positive receptor cells in the vomeronasal organ of CBA and NZB mice were different, in CBA mice Fos-positive cells were noted in both the basal and apical zones, however, in NZB mice activation was observed only in the apical zone [Current Zoology 56 （6）： 813-818, 2010].

关键词： Olfaction Vomeronasal organ Chemosensory receptors Olfactory behavior Immunohistochemistry

SYNTHESIS OF EXFOLIATED ISOTACTIC POLYPROPYLENE/FUNCTIONAL ALKYL-TRIPHENYLPHOSPHONIUM-MODIFIED CLAY NANOCOMPOSITES BY IN SITU POLYMERIZATION

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Chinese Journal of Polymer Science 2013年第11期31卷 1501-1508页

作者： Kai Du 贺爱华 Fu-yong Bi charles C.Han Fine Chemicals Department Beijing Research Institute of Chemical IndustrySINOPEC State Key Laboratory of Polymer Physics and Chemistry Joint Laboratory of Polymer Science and MaterialsBeijing National Laboratory for Molecular ScienceInstitute of ChemistryChinese Academy of Sciences Key Laboratory of Rubber-Plastics Ministry of Education/Shandong Provincial Key Laboratory of Rubber-PlasticsSchool of Polymer Science and EngineeringQingdao University of Science and Technology State Key Laboratory of Polymer Physics and Chemistry Joint Laboratory of Polymer Science and MaterialsBeijingNational Laboratory for Molecular ScienceInstitute of ChemistryChinese Academy of Sciences

Diphenyl （4-hydroxyphenyl） hexadecyl phosphonium bromide （POH） -modified montmorillonite （POHMMT） was used to prepare a novel TiC14/MgC12/POHMMT compound catalyst and exfoliated iPP/POHMMT nanocomposites were prepared by the in situ intercalative polymerization of propylene with the TiC14/MgC12/POHMMT compound catalyst. The POH surfactants don＇t change the catalytic characteristic of the Z-N catalyst and the obtained PP presents high isotacticity, normal molecular weight and molecular weight distribution. The WAXD, SAXS and TEM results demonstrate the highly exfoliated iPP/POHMMT nanocomposites were produced by the in situ polymerization with this novel catalyst, while the intercalated iPP/Na＋MMT nanocomposites were produced with the TiC14/MgC12/Na＋MMT compound catalyst. Through this approach, in situ propylene polymerization can actually take place between the silicate layers and lead not only to PP with high isotacticity and molecular weight, but also to highly exfoliated PP nanocomposites.

关键词： Clay Nanocomposites Poly(propylene) (PP) Ziegler-Natta polymerization.

Vers une nouvelle ère

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Meniscus fabrication of halide perovskite thin films at high throughput for large area and low-cost solar panels

今日中国（法文版） 2024年第1期

作者： charles ONUNAIJU

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International Journal of Extreme Manufacturing 2019年第2期1卷 73-86页

作者： Xuezeng Dai Yehao Deng charles H Van Brackle Jinsong Huang Department of Applied Physical Sciences University of North CarolinaChapel HillNC 27599United States of America

Halide perovskites have rapidly attracted considerable attention due to unprecedented properties not seen in traditional *** addition to their optoelectronic merits,one advantage of perovskite materials is their solution processability,which opens the door to low-cost and high throughput solution coating strategies for the commercialization of perovskite solar cells(PSCs).Here we review perovskite film fabrication by meniscus coating—a simple and readily scalable manufacturing technique,including blade coating and slot-die *** outline the fundamental fluid mechanisms of meniscus coating,discuss drying and crystallization of perovskite in the coating process,and provide an overview of recent progress in meniscus-coated PSCs.

关键词： meniscus coating large area perovskite thin films

Tuning the Morphology of Pharmaceutical Compounds via Model Based Solvent Selection

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Chinese Journal of Chemical Engineering 2008年第3期16卷 465-473页

作者： ArunPrakash T. Karunanithi charles Acquah LukeE. K. Achenie National Risk Management Research Laboratory U.S. Environmental Protection Agency Cincinnati Ohio USA Department of Chemical Materials ＆ Biomolecular Engineering University of Connecticut Storrs Connecticut USA Department of Chemical Engineering Virginia Polytectmic Institute and State University Blacksburg Virginia USA

In this paper we present a strategy for tuning the crystal morphology of pharmaceutical compounds by the appropriate choice of solvent via an optimization model. A three-stage approach involving a pre-design stage, a product design stage and a post-design experimental verification stage is presented. The pre-design stage addresses the tormulation of the property constraint tor crystal morphology. This involves crystallization experiments aria development of property models and constraints for morphology. In the design stage various property requirements for the solvent along with crystal morphology are considered and the product design problem is formulated as a mixed integer nonlinear programming *** design stage provides an optimal solvent/list of candidate solvents. Similar to the pre-design stage, in the post design experimental verification stage, the morphology of the crystals （precipitated from the designed solvent） is verified through crystallization experiments followed by product characterization via scanni＇ng electron microscopy, powder X-ray diffraction imaging and Fourier transform spectra analysis.

关键词： morphology solvent selection nonlinear programming crystallization product design