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Drag models for simulating gas–solid flow in the turbulent fluidization of FCC particles

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Particuology 2009年第4期7卷 269-277页

作者： Peng Li Xingying Lan Chunming xu gang wang Chunxi Lu Jinsen Gao State Key Laboratory of Heavy Oil Processing China University of Petroleum Beijing 102249 China

This paper examines the suitability of various drag models for predicting the hydrodynamics of the turbulent fluidization of FCC particles on the Fluent V6.2 platform. The drag models included those of Syamlal-O＇Brien, Gidaspow, modified Syamlal-O＇Brien, and McKeen. Comparison between experimental data and simulated results showed that the Syamlal-O＇Brien, Gidaspow, and modified Syamlal-O＇Brien drag models highly overestimated gas-solid momentum exchange and could not predict the formation of dense phase in the fiuidized bed, while the McKeen drag model could not capture the dilute charac- teristics due to underestimation of drag force. The standard Gidaspow drag model was then modified by adopting the effective particle cluster diameter to account for particle clusters, which was, however, proved inapplicable for FCC particle turbulent fluidization. A four-zone drag model （dense phase, sub- dense phase, sub-dilute phase and dilute phase） was finally proposed to calculate the gas-solid exchange coefficient in the turbulent fluidization of FCC particles, and was validated by satisfactory agreement between prediction and experiment.

关键词： Turbulent fluidized bed FCC particle Drag model CFD

Situation and Prospect of Energy Consumption for China＇s Thermal Power Generation

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中国电机工程学报 2013年第23期33卷 I0001-I0016页

作者： YANG Yongping YANG Zhiping xu gang wang Ningling North China Electric Power University

Extended Cubic Uniform B-spline and α-B-spline

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自动化学报 2008年第8期34卷 980-983页

作者： xu gang wang Guo-Zhao Institute of Computer Graphics and Image Processing Department of Mathematics Zhejiang University Hangzhou 310027 P. R. China

花键曲线和表面在 CAD 和计算机图形起一个重要作用。在这份报纸，我们建议立方的一致 B 花键的几延期。然后，我们在场插入内推的延期 -B-spline 基于新 B 花键和单个相配技术。延期的优点是他们有全球、本地的形状参数。而且，我们也... 详细信息

花键曲线和表面在 CAD 和计算机图形起一个重要作用。在这份报纸，我们建议立方的一致 B 花键的几延期。然后，我们在场插入内推的延期 -B-spline 基于新 B 花键和单个相配技术。延期的优点是他们有全球、本地的形状参数。而且，我们也在数据插值和多角形的形状变丑调查他们的应用。

关键词：计算机技术 CAD 图象处理技术几何图形

Effects of size variation and spatial structure on plastic response of plant height to light competition

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Chinese Science Bulletin 2010年第12期55卷 1135-1141页

作者： CHEN ShuYan ZHANG JiaLin JIA Peng xu Jin wang gang XIAO Sa Key Laboratory of Arid and Grassland Ecology of Ministry of Education School of Life Science Lanzhou University Lanzhou 730000 China

Plants only interact with neighbors over restricted distances,so local conditions are of great significance for *** this study,a spatially-explicit,individual-based model was constructed to explore the effects of size variation and spatial structure on adaptive plasticity of plant height in response to light *** the model a plant maintains its height at an optimal value in order to maximize its growth rate,and this optimal height increases with the increase of the intensity of light competition experienced by the individual *** the spatial pattern of the population is non-uniform or there is size variation among individual plants,the height growth curves of individuals different from each other vary due to the differences in the local light environment,and there is also variation in the allocation of photosynthate to height growth among the individual *** is no ESS height or height growth strategy on which all plants will *** results indicate that the plasticity of plants' height growth reactions to the light competition should be considered at the individual level and they argue strongly for the importance of the spatial pattern and neighborhood effects in generating the diversity of heights and height growth strategies in plant population.

关键词：空间结构光响应竞争塑料株高空间分布格局变异单株生长曲线

Effects of Long-Term Application of Sulfur-Containing and Chloride-Containing Chemical Fertilizers on Rice Yield and Its Components

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Agricultural Sciences in China 2011年第5期10卷 747-753页

作者： SHEN Pu LI Dong-chu GAO Ju-sheng xu Ming-gang wang Bo-ren HOU Xiao-juan Institute of Agricultural Resources and Regional Planning Chinese Academy of Agricultural Sciences/Key Laboratory of Crop Nutrition and Fertilization Ministry of Agricultur Beijing 100081 P.R. China

Impacts of 33-yr of application of S-containing and Cl-containing chemical fertilizers on rice （Oryza sativa L.） yield and its components were investigated in a red paddy field experiment,south *** treatments included：1） adding 302 kg SO42--S ha-1 yr-1 with application of （NH4）2SO4-,K2SO4,and calcium superphosphate （SO42-）;2） adding 56 kg SO42--S and 176 kg Cl ha-1 yr-1 with application of urea,calcium superphosphate,and KCl （Cl-＋SO42-）;3） adding 516 kg Cl ha-1 yr-1 with application of NH4Cl,KCl,and KH2PO4 （Cl-）.Under each treatment,the applied N,P,and K nutrients were controlled at conventional rates of 150 kg N ha-1 yr-1,75 kg P2O5 ha-1 yr-1,225 kg K2O ha-1 yr-1,*** the S-containing fertilizer application,soil SO42--S content showed a first increasing then decreasing trend with years,and was significantly negatively correlated with annual rice *** annual yield significantly declined in an order of Cl-,Cl-＋SO42-,and SO42-.Under the Cl-treatment,soil SO42--S content was maintained at about 26.5 mg kg-1,not showing *** 1990 to 2000,rice yield declined rapidly under the SO42- treatment,and was significantly lower than that under the *** then,there was no significant difference in yield among the *** results demonstrated that long-term application of S- containing fertilizer could result in excessive accumulation of SO42--S in the red paddy soils of south China,therefore producing a certain threat to rice *** Cl- containing fertilizer could be relatively safe.

关键词： rice (Oryza sativa L.) long-term fertilization,componentsulfur-containing fertilizer chloride-containing fertilizer yield,

Scorpion Venom Heat-Resistant Peptide is Neuroprotective against Cerebral Ischemia-Reperfusion Injury in Association with the NMDA-MAPK Pathway

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Neuroscience Bulletin 2020年第3期36卷 243-253页

作者： xu-gang wang Dan-Dan Zhu Na Li Yue-Lin Huang Ying-Zi wang Ting Zhang Chen-Mei wang Bin wang Yan Peng Bi-Ying Ge Shao Li Jie Zhao Liaoning Provincial Key Laboratory of Cerebral Diseases Department of PhysiologyCollege of Basic Medical SciencesDalian Medical UniversityDalian 116044China National-Local Joint Engineering Research Center for DrugResearch and Development of Neurodegenerative Diseases Dalian Medical UniversityDalian 116000China The Second Hospital of Dalian Medical University Dalian 116023China

Scorpion venom heat-resistant peptide(SVHRP)is a component purified from Buthus martensii Karsch scorpion venom. Our previous studies have shown that SVHRP is neuroprotective in models of Alzheimer’s disease and Parkinson’s disease. The present study aimed to explore the potential neuroprotective effects of SVHRP on cerebral ischemia/reperfusion(I/R) injury, using a mouse model of middle cerebral artery occlusion/reperfusion(MCAO/R) and a cellular model of oxygen-glucose deprivation/reoxygenation(OGD/R). Our results showed that SVHRP treatment decreased the neurological deficit scores, edema formation, infarct volume and neuronal loss in the MCAO/R mice, and protected primary neurons against OGD/R insult. SVHRP pretreatment suppressed the alterations in protein levels of N-methyl-D-aspartate receptors(NMDARs) and phosphorylated p38 MAPK as well as some proinflammatory factors in both the animal and cellular models. These results suggest that SVHRP has neuroprotective effects against cerebral I/R injury, which might be associated with inhibition of the NMDA-MAPKmediated excitotoxicity.

关键词： Scorpion venom heat-resistant peptide Cerebral ischemia/reperfusion injury Neuroprotection NMDARs p38 MAPK

Cryogenic springback of 2219-W aluminum alloy sheet through V-shaped bending

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Transactions of Nonferrous Metals Society of China 2024年第10期34卷 3185-3193页

作者： Xiao-bo FAN Qi-liang wang Fang-xing WU xu-gang wang School of Mechanical Engineering Dalian University of TechnologyDalian 116081China School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150096China

A V-shaped bending device was established to evaluate the effects of temperature and bending fillet radius on springback behavior of 2219-W aluminum alloy at cryogenic *** cryogenic springback mechanism was elucidated through mechanical analyses and numerical *** results indicated that the springback angle at cryogenic temperatures was greater than that at room *** springback angle increased further as the temperature returned to ambient conditions,attributed to the combined effects of the “dual enhancement effect” and thermal ***,a critical fillet radius made the springback angle zero for 90° V-shaped *** critical fillet radius at cryogenic temperatures was smaller than that at room temperature,owing to the influence of temperature variations on the bending moment ratio between the forward bending section at the fillet and the reverse bending section of the straight arm.

关键词： 2219-W aluminum alloy cryogenic forming V-shape bending springback critical fillet radius

Estimation of forest volumes by integrating Landsat TM imagery and forest inventory data

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Science China(Technological Sciences) 2006年第z1期49卷 54-62页

作者： GU Huiyan, DAI Limin, WU gang, xu Dong, wang Shunzhong &wang Hui Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China School of Forestry, Northeast Forestry University, Harbin 150040, China State Key Lab of Systems Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China Graduate University of Chinese Academy of Sciences, Beijing 100039, China Institute of Applied Ecology Chinese Academy of Sciences Shenyang 110016 China School of Forestry Northeast Forestry University Harbin 150040 China State Key Lab of Systems Ecology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China Graduate University of Chinese Academy of Sciences Beijing 100039 China

Accurate information about forest volumes is essential for forest management planning. The survey interval of the Forest Resource Inventory of China (FRIC) is too long to meet the demand for timely decision-making required for forest protection, management, and utilization. Analysis of satellite imagery provides good potential for more frequent reporting of forest parameters. In this study, we describe an application of the k-nearest neighbors (kNN) method to Landsat TM imagery for improving estimation of forest volumes. Several spectral features were tested and compared in forest volume estimations, including normalized difference vegetation index, environmental vegetation index, and the combination of the spectral features. The combined index resulted in the most accurate volume estimations. The kNN estimator and the combined index were then used in forest volume estimation. The estimation error (RMSE) of the total volume was44.2%, much lower than those for Larix forest (the RMSE was 51.7%) and those for the Korean pine and broadleaved forests (the estimation errors were over 71.7% and 88.19%,respectively). This preliminary study demonstrates the potential of forest volume estimations with remote sensing data to provide useful information for forest management if only limited ground information is available.

关键词： forest inventory, landsat TM, k-nearest neighbors, spectral extraction.

Use of the "double barrel" free vascularized fibula and osseointegrated dental implants in mandibular reconstruction

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Use of the "double barrel" free vascularized fibula and osse...