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Effects of grid size on predictions of bed expansion in bubbling fluidized beds of Geldart b particles： A generalized rule for a grid-independent solution of TFM simulations

Natural Science（自然科学期刊） 2024年第5期 45页

作者： Riley J. Wincheski Kiri Li N. Stauch Laura M. Grossner Maya b. Zepeda James W. Grice charles I. Abramson

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Particuology 2017年第5期15卷 61-69页

作者： M. Helal Uddin charles J. Coronella Department of Chemical and Materials Engineering University of Nevada Reno NV 89557 USA

Numerical simulations of gas-solid fluidized beds based on the kinetic theory of granular flow exhibit a significant dependence on domain discretization. bubble formation, bubble size and shape all vary greatly with the discretization, and the use of an inappropriate scale resolution leads to inaccurate predictions of fluidization hydrodynamics. In this study, grid-independent solutions of the two fluid model were examined by comparing the bed expansions obtained from numerical simulations with experimental results and empirical predictions, based on bubbling fluidized beds of Geldart b particles. Grid indepen- dence was achieved with a grid resolution equal to 18 times the particle diameter. The simulation results were compared with previously published data for verification purposes. The results of this work should provide a guideline for choosing the appropriate grid size and thereby minimize the time and expense associated with large simulations.

关键词： Mesh effectHydrodynamicsComputational fluid dynamicsEuler-Euler method MFIX

Hydrometallurgical detoxification and recycling of electric arc furnace dust

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International Journal of Minerals,Metallurgy and Materials 2023年第11期30卷 2076-2094页

作者： Yang Xue Xiaoming Liu Chunbao(charles)Xu Yonghui Han State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China Department of Chemical&biochemical Engineering Western UniversityLondonON N6A 5B9Canada Hebei Technology Innovation Centre of Solid Wastes Utilization Hebei University of Science and TechnologyShijiazhuang 050091China

Electric arc furnace dust(EAFD)is a hazardous waste but can also be a potential secondary resource for valuable metals,such as Zn and *** the increased awareness of carbon emission reduction,energy conservation,and environmental protection,hydrometallurgical technologies for the detoxification and resource use of EAFD have been developing *** work summarizes the generation mechanisms,compositions,and characteristics of EAFD and presents a critical review of various hydrometallurgical treatment methods for EAFD,e.g.,acid leaching,alkaline leaching,salt leaching,and pretreatment–enhanced leaching ***,the phase transformation mechanisms of zinc-containing components in acid and alkali solutions and pretreatment processes are ***,two novel combined methods,i.e.,oxygen pressure sulfuric acid leaching combined with composite catalyst preparation,and synergistic roasting of EAFD and municipal solid waste incineration fly ash combined with alkaline leaching,are proposed,which can provide future development directions to completely recycling EAFD by recovering valuable metals and using zinc residue.

关键词： hazardous waste recycling separation zinc hydrometallurgical technologies

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INTERVALS OF NEAR-DEGENERACY IN RATIONAL APPROXIMATION

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Analysis in Theory and Applications 1986年第3期 73-76页

作者： charles b.Dunham Canada N6A 5b7 Computer Science Department The University of Western Ontario London Ontario

This note is concerned with a difficulty in uniform（Cheby-shev,L;）approximation of a continuous function f by ordinaryrational functions R;[α,β]on finite intervals[α,β]:such ap-proximations are used to construct... 详细信息

关键词： INTERVALS OF NEAR-DEGENERACY IN RATIONAL APPROXIMATION

Strain engineering of electro-optic constants in ferroelectric materials

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npj Computational Materials 2019年第1期5卷 1092-1096页

作者： charles Paillard Sergei Prokhorenko Laurent bellaiche Department of Physics and Institute for Nanoscience and Engineering University of ArkansasFayettevilleAR 72701USA

Electro-optic effects allow control of the ow of light using electric fields,and are of utmost importance for today’s information and communication technologies,such as TV displays and fiber *** search for large electro-optic constants in films is essential to the miniaturization and increased efficiency of electro-optic *** this work,we demonstrate that strain-engineering in PbTiO_(3) films allows to selectively choose which electro-optic constant to *** electro-optic constants larger than 100 pm V^(−1) are predicted,either by driving the softening of an optical phonon mode at a phase transition boundary under tensile strain,or by generating the equivalent of a negative pressure via compressive strain to obtain large piezoelectric *** particular,a r_(13) electro-optic coefficient twice as large as the one of the commonly used LiNbO_(3) electro-optic material is found here when growing PbTiO_(3) on the technologicallyimportant Si substrate.

关键词： softening constants ferroelectric

Global leaf nitrogen and phosphorus stoichiometry and their scaling exponent

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National Science Review 2018年第5期5卷 728-739页

作者： Di Tian Zhengbing Yan Karl J.Niklas Wenxuan Han Jens Kattge Peter b.Reich Yongkai Luo Yahan Chen Zhiyao Tang Huifeng Hu Ian J.wright bernhard Schmid Jingyun Fang Institute of Ecology College of Urban and Environmental Sciencesand Key Laboratory for Earth Surface Processes of the Ministry of EducationPeking University Max-Planck-Institute for biogeochemistry State Key Laboratory of Vegetation and Environmental Change Institute of BotanyChinese Academy of Sciences College of Life Sciences Capital Normal University Department of Plant biology Cornell University Department of Forest Resources University of Minnesota Department of biological Sciences Macquarie UniversitySydneyNSW 2109Australia10 Department of Evolutionary Biology and Environmental StudiesUniversity of Zurich Hawkesbury Institute for the Environment Western Sydney University Key Laboratory of Plant-Soil Interactions Ministry of EducationCollege of Resources and Environmental SciencesChina Agricultural University

Leaf nitrogen(N) and phosphorus(P) concentrations constrain photosynthetic and metabolic processes,growth and the productivity of plants. Their stoichiometry and scaling relationships regulate the allocation of N and P from subcellular to organism, and even ecosystem levels, and are crucial to the modelling of plant growth and nutrient cycles in terrestrial ecosystems. Prior work has revealed a general biogeographic pattern of leaf N and P stoichiometric relationships and shown that leaf N scales roughly as two-thirds the power of P. However, determining whether and how leaf N and P stoichiometries, especially their scaling exponents, change with functional groups and environmental conditions requires further verification. In this study, we compiled a global data set and documented the global leaf N and P concentrations and the N:P ratios by functional group, climate zone and continent. The global overall mean leaf N and P concentrations were 18.9 mg gand 1.2 mg g, respectively, with significantly higher concentrations in herbaceous than woody plants(21.72 mg gvs. 18.22 mg gfor N; and 1.64 mg gvs. 1.10 mg gfor P). both leaf N and P showed higher concentrations at high latitudes than low latitudes. Among six continents, Europe had the highest N and P concentrations(20.79 and 1.54 mg g) and Oceania had the smallest values(10.01 and 0.46 mg g). These numerical values may be used as a basis for the comparison of other individual studies. Further, we found that the scaling exponent varied significantly across different functional groups,latitudinal zones, ecoregions and sites. The exponents of herbaceous and woody plants were 0.659 and0.705, respectively, with significant latitudinal patterns decreasing from tropical to temperate to boreal zones. At sites with a sample size ≥10, the values fluctuated from 0.366 to 1.928, with an average of *** factors including the intrinsic attributes of different life forms, P-related growth rates and relative nutrient availa

关键词： leaf nitrogen phosphorus stoichiometry scaling exponent functional group biogeography

Ultra-broadband and polarization-independent planar absorber based on multilayered graphene

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Chinese Physics b 2017年第11期26卷 186-192页

作者：王娇高超宁姜彦南 charles Nwakanma Akwuruoha Guangxi Key Laboratory of Wireless Wideband Communication and Signal Processing Key Laboratory of Cognitive Radio and Information Processing (Ministry of Education) Guilin University of Electronic Technology School of Electrical and Electronic Engineering University of Manchester

We propose an ultra-broadband and polarization independent planar absorber comprising multilayered graphene. The bandwidth of the proposed absorber is extended by increasing the number of layers of graphene, and it is polarization independent due to its symmetrical unit structure. The full wave simulation results show that an absorber with three graphenebased layers can efficiently harvest an electromagnetic wave with random polarization from 17.9 GHz to 188.7 GHz（i.e.,covering frequency regimes from K to D bands and relative bandwidth of - 165%）. The physical absorption mechanism of ultra-broadband absorption has been elaborated upon using the destructive interference method and multiple resonances approach in a multilayered medium. The proposed absorber can be used in many applications such as medical treatment,electromagnetic compatibility, and stealth technique.

关键词： multilayered graphene absorber ultra-broadband polarization independent

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Novel decoupled framework for reliability-based design optimization of structures using a robust shifting technique

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Frontiers of Structural and Civil Engineering 2019年第4期13卷 800-820页

作者： Mohammad Reza GHASEMI charles V. CAMP babak DIZANGIAN Department of Civil Engineering University of Sistan and Baluchestan Zahedan *** Iran Department of Civil Engineering The University of Memphis Memphis TN 38152 USA Department of Civil Engineering Velayat University Iranshahr *** Iran

In a reliability-based design optimization (RbDO), computation of the failure probability (Pf) at all design points through the process may suitably be avoided at the early stages. Thus, to reduce extensive computations of RbDO, one could decouple the optimization and reliability analysis. The present work proposes a new methodology for such a decoupled approach that separates optimization and reliability analysis into two procedures which significantly improve the computational efficiency of the RbDO. This technique is based on the probabilistic sensitivity approach (PSA) on the shifted probability density function. Stochastic variables are separated into two groups of desired and non-desired variables. The three-phase procedure may be summarized as: Phase 1, apply deterministic design optimization based on mean values of random variables;Phase 2, move designs toward a reliable space using PSA and finding a primary reliable optimum point;Phase 3, applying an intelligent self-adaptive procedure based on cubic b-spline interpolation functions until the targeted failure probability is reached. An improved response surface method is used for computation of failure probability. The proposed RbDO approach could significantly reduce the number of analyses required to less than 10% of conventional methods. The computational efficacy of this approach is demonstrated by solving four benchmark truss design problems published in the structural optimization literature.

关键词： reliability-based design optimization trusses sensitivity analysis shifting technique cubic b-splines response surface method

A novel E153X point mutation in the androgen receptor gene in a patient with complete androgen insensitivity syndrome

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Asian Journal of Andrology 1999年第1期1卷 73-77页

作者： Silvia b Copelli Serge Lumbroso Francoise Audran Eliana H Pellizzari Juan J Heinrich Selva b Cigorraga charles Sultan Héctor E Chemes Laboratore d'Hormonologie Hopital Lapeyronie et INSER U 439 Pathologie des recepteurs nucleaires.Unite d'Endocrinologie et Gynecologie PediatriquesHopital A.de VillenetiveMontpellier-France CEDIE-CONICET Division de EndocrinologtaHospital de Niflos"Ricardo Gutierrez"Buenos AiresArgentina

Aim:To study a 46,XY newborn patient with a phenotype suggestive of an androgen insensitivity syndrome toconfirn an anomaly in the AR ***:Genomic DNA from leukocytes was isolated in order to analyze SRYgene by PCR and sequencing of the eight exons of AR *** of human Leydig cell mesenchymal precursorsfrom the testis was performed in order to study testosterone production and response to hCG stimulation in ***:Surgical exploration disclosed two testes,no Wolffian structures and important Mullerian *** gene was present in peripheral blood *** of the AR gene evidenced a previously unreported Gto T transversion in exon 1 that changed the normal glutamine 153 codon to a stop *** cell culturesproduced sizable amounts of testosterone and were responsive to hCG ***:This E153X nonsensepoint mutation has not been described previously in cases of AIS,and could lead to the synthesis of a short truncated(153 vs 919 residues)non functional AR probably responsible for the phenotype of complete androgen insensitivitysyndrome(CAIS).

关键词： testicular feminization androgen receptor point mutation Mullerian ducts

Diurnal variation in fecal concentrations of acid-detergent insoluble ash and alkaline-peroxide lignin from cattle fed bermudagrass hays of varying nutrient content

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Journal of Animal Science and biotechnology 2015年第4期6卷 410-415页

作者： Juvenal Kanani Dirk Philipp Kenneth P Coffey Elizabeth b Kegley charles P West Shane Gadberry John Jennings Ashley N Young Robert T Rhein Division of Agriculture University of Arkansas Department of Plant and Soil Science Texas Tech University

background： The effect of time of fecal sampling on the accuracy of acid-detergent insoluble ash （ADIA） and alkaline-peroxide lignin （APL） for the prediction of fecal output （FO） in cattle was evaluated. Eight ruminally cannulated cows （594 _＋ 35.5 kg） were allocated randomly to 4 bermudagrass [Cynodon dactylon （L.） Pers.] hay diets markedly different in crude protein concentration （79-164 g/kg） with 2 replicates per diet for 3 periods. Cows were offered hay individually at 20 g DM/kg of body weight daily in equal feedings at 08：00 and 16：00 h for a 10-d adaptation period followed by 5-d of total fecal collection. Fecal grab samples also were taken each day during the fecal collection period at 06：00, 12：00, 18：00, and 24：00 h either directly from the rectum or from freshly voided feces. Samples were composited within cow and time across the 5 d total fecal collection period. Additionally, forage, ort, and fecal samples were analyzed for concentrations of APL and ADIA. Results： Fecal concentrations of ADIA and APL were not affected by sampling time （P 〉 0.22）, even though diet affected （P 〈 0.01） fecal ADIA and APL concentrations. There were no diet x sampling time interactions （P ≥ 0.60）. Estimates of FO and dry matter digestibility （DMD） from ADIA and APL were not affected （P 〉 0.16） by sampling time or the diet x sampling time interaction （P 〉 0.74）. Estimates of FO and DMD from markers from different sampling times or all different combinations of sampling time were not different （P 〉 0.72） from those of total collection among internal markers. Conclusion： Little variation in concentrations of ADIA and APL in daily fecal excretion across time increases flexibility in fecal grab sampling schedules for predicting FO and DMD.

关键词： Digestibility Fecal sampling time Internal markers bermudagrass Cattle

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