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Liquid inj.ction, and film formation and transport in dense-phase gas-solids fluidized beds are numerically simulated in three dimensions using a collisional exchange model that is based on the mechanism that collisions cause transfer of liquid mass, momentum, and energy between particles. In the model, each of the particles is represented by a solid core and a liquid film surrounding the core. The model is incorporated in the framework of the commercial code Barracuda developed by CPFD Software. The commercial software is an advanced CFD-based computational tool where the particles are treated as discrete entities, calculated by the MP-PIC method, and tracked using the Lagrangian method. Details of the collisional liquid transfer model have been previously presented in o＇Rourke, Zhao, and Snider （2009）; this paper presents new capabilities and proof-testing of the collision model and a new method to better quantify the penetration length. Example calculations of a fluidized bed without liquid inj.ction show the expected effect of collisions on the reduction of granular temperature （fluctuational kinetic energy） of the bed. When applied to liquid inj.ction into a dense-phase fluidized bed under different conditions, the model predicts liquid penetration lengths comparable to the experiments. In addition, the simulation reveals for the first time the dynamic mixing of the liquid droplets with the bed particles and the transient distribution of the droplets inside the bed.

关键词： MP-PIC Liquid inj.ction Fluidized bed Particle collisions CPFD j.t penetration

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Tipping points among social learners： Tools from varied disciplines

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Current Zoology 2012年第2期58卷 298-306页

作者： R. Alexander BENTLEY Michael j. o＇BRIEN Department of Archaeology and Anthropology University of Bristol Bristol BS8 1UU UK Department of Anthropology University of Missouri Columbia MO 65211 USA

There is a long and rich tradition in the social sciences of using models of collective behavior in animals as j.mping-off points for the study of human behavior, including collective human behavior. Here, we come at the problem in a slightly different fashion. We ask whether models of collective human behavior have anything to offer those who study animal behavior. our brief example of tipping points, a model first developed in the physical sciences and later used in the social sciences, suggests that the analysis of human collective behavior does indeed have considerable to offer [Current Zoology58 (2): 298–306, 2012].

关键词：社会科学引爆人类行为工具学习行为模式动物行为物理科学

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organochlorine Pesticides(oCPs) in Soils Along the Eastern Slope of the Tibetan Plateau

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Pedosphere 2010年第5期20卷 607-615页

作者： XING Xin-Li QI Shi-Hua ZHANG Yuan YANG Dan j. o. oDHIAMBo Key Laboratory of Biogeology and Environmental Geolagy of Ministry o.f Education China University of Geosciences Wuhan 430074 (China) School of Environmental Studies China University of Gcosciences Wuhan 430074 (China)

Soil samples collected from several sites along an altitudinal transect on the eastern slope of the Tibetan Plateau were analyzed for hexachlorobenzenes(HCHs) and dichlorodiphenyltrichloroethanes(DDTs).The results showed that HCHs and DDTs were found in the soil samples from the remote high altitude areas away from source regions,which confirmed the long-range atmospheric transport phenomenon of these organochlorine pesticides(oCPs) *** oCP concentrations in the soils had a significant negative correlation with altitude;they showed a trend to increase with decreasing altitude,but the increase was not continuous,being interrupted at some moderate-altitude sites on the *** distances from the source region,landforms,soil properties,and physical-chemical properties of oCPs were more important than total organic carbon content to the distribution of oCPs in soils disturbed by human *** analysis of the compositions of HCH isomers and DDTs revealed predominantly low ratios of α-HCH to γ-HCH,ranging from 0.06 to 4.79,which suggested current lindane *** the other hand,low p,p-DDT/p,p-DDE and o,p-DDT/p,p-DDT ratios were observed,indicating mainly aged historical DDT residues in the study area.

关键词：有机氯农药土壤样品青藏高原六氯环己烷高海拔地区远距离传输东坡人类活动干扰

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on the analytical solution of transient friction in channel flows

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Applied Mathematics and Mechanics(English Edition) 2024年第8期45卷 1447-1466页

作者： F.j.GARCíA-GARCíA P.FARI?AS-ALVARI?o Department of Naval & Industrial Engineering Polytechnic School of EngineeringUniversity of A Coru?a Campus Industrial de Ferrol Integraciones Técnicas de Seguridad S.A. Pol.Ind.Espíritu Santo

The transient friction in channel mean flows is the sum of two contributions,i.e., the underlying laminar flow(ULF) and the purely turbulent component(PTC), and the contributions are analyzed separately by theoretical experiments. It is found that,the transient friction may be higher or remarkably lower than that in equal-Reynolds number steady-state flows. The universal time constant for plane-parallel laminar flows is reported, and the role of the time constant in a turbulent mean flow is examined. It is shown that the time constant is related to the turbulence's frozen time. Finally, a study of the logarithmic layer during the transient flow is accomplished, which shows that the logarithmic layer is destroyed.

关键词： 76D05 76D06 76F55 o361 transient flow transient friction unsteady channel flow

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Changes in feeding selectivity of freshwater invertebrates across a natural thermal gradient

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Current Zoology 2018年第2期64卷 231-242页

作者： Timothy A. C. GoRDoN j.ana NETo-CEREj.IRA Paula C. FUREY Eoin j. o'GoRMAN Imperial College London Silwood Park Campus Buckhurst Road Ascot Berkshire SL5 7PY UK Biosciences College of Life and Environmental Sciences University of Exeter Stocker Road Exeter EX4 4QD UK Department of Biology Saint Catherine University St Paul MN 55105 USA

Environmental warming places physiological constraints on organisms, which may be mitigated by their feeding behavior. Theory predicts that consumers should increase their feeding selectivity for more energetically valuable resources in warmer environments to offset the disproportionate increase in metabolic demand relative to ingestion rate. This may also result in a change in feeding strategy or a shift towards a more specialist diet. This study used a natural warming experiment to investigate temperature effects on the feeding selectivity of three freshwater invertebrate grazers: the snail , the blackfly larva , and the midgefly larva . Chesson's Selectivity Index was used to compare the proportional abundance of diatom species in the guts of each invertebrate species with corresponding rock biofilms sampled from streams of different temperature. The snails became more selective in warmer streams, choosing high profile epilithic diatoms over other guilds and feeding on a lower diversity of diatom species. The blackfly larvae appeared to switch from active collector gathering of sessile high profile diatoms to more passive filter feeding of motile diatoms in warmer streams. No changes in selectivity were observed for the midgefly larvae, whose diet was representative of resource availability in the environment. These results suggest that key primary consumers in freshwater streams, which constitute a maj.r portion of invertebrate biomass, can change their feeding behavior in warmer waters in a range of different ways. These patterns could potentially lead to fundamental changes in the flow of energy through freshwater food webs.

关键词：无脊椎动物淡水自然坡度生物资源新陈代谢行业协会可获得性

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计算机科学引论

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作者： (美)Timothy j. o＇Leary Linda l.o’Leary

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Search for Double γ-Vibrational Bands in Neutron-Rich ^105Mo Nucleus

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Chinese Physics Letters 2006年第12期23卷 3222-3225页

作者：丁怀博朱胜江 j. H. Hamilton A. V. Ramayya j. K. Hwang Y. X. Luo j. o. Rasmussen I. Y. Lee 车兴来陈永静李明亮 Department of Physics Tsinghua University Beijing 100084 Department of Phvsics Vanderbilt University Nashville Tennessee 37235 USA Lawrence Berkeley National Laboratory Berkeley California 94720 USA

Levels in the neutron-rich ^105Mo nucleus have been investigated by observing prompt γ-rays following the spontaneous fission fragments of^252 Cf with the Gammasphere detector array. The yrast band has been confirmed and updated. The other two collective bands with the band head levels at 870.5 and 1534.6 keV are newly observed, and they are suggested as the candidates for one-phonon K= 9/2 and two-phonon K = 13/2 double γ-vibrational bands, respectively. Systematic characteristics of these bands have been discussed.

关键词： Double γ-Vibrational Bands Systematic characteristics

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