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CURVED OPEN CHANNEL FLOW ON VEGETATION ROUGHENED INNER BANK

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Journal of Hydrodynamics 2012年第1期24卷 124-129页

作者： HUAI Wen-xin LI Cheng-guang ZENG Yu-hong qian zhong-dong YANG zhong-hua State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan UniversityWuhan 430072China

A RNG numerical model together with a laboratory measurement with Micro ADV are adopted to investigate the flow through a 180o curved open channel（a 4 m straight inflow section,a 180o curved section,and a 4m straight outflow section）partially covered with rigid vegetations on its inner *** the combined action of the vegetation and the bend flow,the flow structure is *** stream-wise velocities in the vegetation region are much smaller than those in the non-vegetation region due to the retardation caused by the *** the same reason,no clear circulation is found in the vegetated region,while in the non-vegetation region,a slight counter-rotating circulation is found near the outer bank at both 90o and downstream curved cross-sections.A comparison between the numerical prediction and the laboratory measurement shows that the RNG model can well predict the flow structure of the bend flow with ***,the shear stress is analyzed based on the numerical *** much smaller value in the inner vegetated region indicates that the vegetation can effectively protect the river bank from scouring and erosion,in other words,the sediment is more likely to be deposited in the vegetation region.

关键词： RNG numerical model non-submerged rigid vegetation bend flow stream-wise velocities shear stress

Numerical simulation of air entrainment and suppression in pump sump

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Science China(Technological Sciences) 2016年第12期59卷 1847-1855页

作者： qian zhong dong WU Peng Fei GUO Zhi Wei HUAI Wen Xin State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan University

The dynamics of air entrainment and suppression schemes in a pump sump are investigated. Four different turbulence models(standard k-ε model, realizable k-ε model, renormalization group(RNG) k-ε model and shear-stress transport(SST) k-ω model) and the volume of fluid(VOF) multiphase model are employed to simulate the three-dimensional unsteady turbulent flow in a pump sump. The dynamic processes of air entrainment are simulated under conditions of relatively high discharge and low submergence; the mechanism of air entrainment is discussed in detail. Then suppression means for air entrainment is adopted by placing a circular plate on the intake pipe at three different heights. The results show: the position and structure of the free-surface vortices, sidewall-attached vortices, back wall-attached vortices, and floor-attached vortices calculated by SST k-ω turbulence model agree well with the experimental data. The two main contributors for air entrainment are pressure difference and vortex strength. By placing a circular plate in the middle of the intake pipe under water, air entrainment is suppressed because vortex strength is reduced.

关键词： air entrainment suppression schemes pump sump VOF

NUMERICAL STUDY OF FLOW AND DILUTION BEHAVIOR OF RADIAL WALL JET

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Journal of Hydrodynamics 2010年第5期22卷 681-688页

作者： LI Zhi-wei HUAI Wen-xin qian zhong-dong ZENG Yu-hong YANG zhong-hua State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan University Wuhan 430072 China

The radial wall jet is a flow configuration that combines the radial jet and the wall jet. This article presents a simulation of the radial wall jet by applying the transition Shear-Stress Transport （ SST） model. Tanaka’s experimental data are used for validation. The computed velocity profiles agree well with the experimental ones. The distributions of the velocity on cross-sections show a similarity in the main region and the profiles are different with those of the free radial jet or the wall jet, because the presence of the wall limits the expansion of the jet. By introducing the equivalent nozzle width, the maximum velocity decays and the half-width distributions are normalized, respectively. In addition to compare the flow field with experiments, this paper also analyzes the dilution effect of radial wall jets in terms of the concentration distributions. The concentrations on the wall keep constant within a certain distance from the nozzle. And the concentration distributions also show a similarity in the main region. Both the decays of the maximum concentration and the distributions of the concentration half-width fall into a single curve, respectively. The dilution effect of radial wall jets is thus verified.

关键词： radial wall jet velocity profile concentration distribution concentration half-width

LARGE EDDY SIMULATION OF OPEN CHANNEL FLOWS WITH NONSUBMERGED VEGETATION

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Journal of Hydrodynamics 2011年第2期23卷 258-264页

作者： HUAI Wen-xin WU Zhen-lei qian zhong-dong GENG Chuan State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan University Wuhan 430072 China

Results of several Large Eddy Simulations （LES） this article. It is shown that the vegetation can make the flow of open channel flows with non-submerged vegetation are presented in structure in the mainstream direction uniform for both supercritical and subcritical flows. For subcritical flows, the LES results of the ensemble-average of time-averaged velocity distributions at four vertical sections around a single plant are in good agreement with measurements. The velocity sees double peaks at the upper and lower positions of flows. For supercritical flows, the ensemble-average velocities see some discrepancy between LES and measurement results. Some secondary flow eddies appear near the single plant, and they just locate in the positions of the double peaks in stream-wise velocity profiles. It is also found that the vegetation drag coefficient deceases as the Froude number increases.

关键词： non-submerged sub/supercritical flow peak value Large Eddy Simulation (LES) secondary flow drag coefficient

NUMERICAL SIMULATION OF HORIZONTAL BUOYANT WALL JET

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Journal of Hydrodynamics 2010年第1期22卷 58-65页

作者： HUAI Wen-xin LI Zhi-wei qian zhong-dong ZENG Yu-hong HAN Jie PENG Wen-qi State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan University Wuhan 430072 China Department of Water Environment China Institute of Water Resources and Hydropower Research Beijing100038 China

This article applies the realizable k - ω model to simulate the buoyant wall jet and gives the results of cling length, centerline trajectory and temperature dilutions at certain sections. The comparison between the numerical results and Sharp＇s experimental data indicates that the model is effective in estimating velocity distribution and temperature dilutions. The velocity profiles at the cental plane and z-plane both show a strong similarity at certain distance from the nozzle, and the distributions of velocity and temperature dilutions also exhibit a similarity along the axial direction at centerline in the near-field. Based on the results, the article gives the corresponding relationships between the distance and the dilutions of velocity and temperature, which is useful in predicting the behavior of the wall buoyant jet.

关键词： buoyancy wall jet cling length velocity profile temperature dilution

Decision and Coordination in a Closed-Loop Supply Chain with Product Recycling Under Different Low-Carbon Regulations

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Journal of the Operations Research Society of China 2024年第3期12卷 695-728页

作者： qian-dong dong Hai-Wen Xu School of Management and Engineering Nanjing UniversityNanjing210093JiangsuChina School of Science Civil Aviation Flight University of ChinaGuanghan618307SichuanChina

The implementation of recycling activity is of great significance to closed-loop supply chain ***’environmental awareness and governmental subsidy are considered in the two-echelon closed-loop supply *** types of decision-making structures are proposed under different carbon emission *** subsidy sharing mechanism is designed to resolve the channel members’conflict caused by double *** paper provides insight into the effect of environmental awareness and government subsidy under different low-carbon regulations on the supply chain benefit and social welfare via the game *** analysis results display that the government subsidy and subsidy sharing mechanism are profitably beneficial to the whole supply chain and social ***,a noteworthy result reveals that social welfare is not always directly proportional to consumers’environmental *** welfare decreases slightly with the increase in consumers’environmental awareness when consumers’environmental awareness is ***,social welfare will be significantly improved when consumers’environmental awareness increases beyond a certain threshold.

关键词： Closed-loop supply chain Recycling Coordination Social welfare Game theory Carbon emissions

Contrasting strategies of optimizing carrier concentration in bulk InSe for enhanced thermoelectric performance

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Rare Metals 2024年第9期43卷 4425-4432页

作者： Hao-Nan Shi Shu-Lin Bai Yu-Ping Wang Li-zhong Su qian Cao Cheng Chang Li-dong Zhao School of Materials Science and Engineering Beihang UniversityBeijing 100191China School of Materials Science and Engineering Taiyuan University of Science and TechnologyTaiyuan 030024China Huabei Cooling Device Co.Ltd. Hebei 065400China

Indium selenide(InSe),as a wide-bandgap semiconductor,has received extensive attention in the flexible electronics field in recent years due to its exceptional plasticity and promising thermoelectric ***,the low carrier concentration severely limits its thermoelectric performance *** this work,we conducted contrasting strategies that can be employed to increase the carrier concentration of InSe,including bandgap narrowing and heterovalent ***,the carrier concentration initially increases as a result of the reduced bandgap upon Te alloying and then slightly decreases due to the weak electronegativity of *** Br doping realizes high carrier concentration by pushing the Fermi level into the conduction bands and activating the multiple *** the other hand,both Te and Br obviously suppress the thermal conductivity due to the point defect *** contrast,Br doping realizes a higher thermoelectric performance with a maximum ZT of~0.13 at 773 K benefiting from the better optimization of carrier *** work elucidates the strategies for enhancing carrier concentration at anion sites and demonstrates the high efficiency of halogen doping in ***,the carrier concentration of InSe is promising to be further optimized,and future work should focus on employing approaches such as cation doping or secondphase compositing.

关键词： Thermoelectric InSe Carrier concentration Bandgap Heterovalent doping

Overexpression of the peroxidase gene ZmPRX1 increases maize seedling drought tolerance by promoting root development and lignification

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The Crop Journal 2024年第3期12卷 753-765页

作者： Xiuzhen Zhai Xiaocui Yan Tinashe Zenda Nan Wang Anyi dong qian Yang Yuan zhong Yue Xing Huijun Duan State Key Laboratory of North China Crop Improvement and Regulation Key Laboratory of Crop Germplasm Resources in North China Ministry of EducationCollege of AgronomyHebei Agricultural UniversityBaoding 071001HebeiChina

Drought is a main abiotic stress factor hindering plant growth,development,and crop ***,it is crucial to understand the mechanisms by which plants cope with drought ***,the function of the maize peroxidase gene ZmPRX1 in drought stress tolerance was investigated by measurement of its expression in response to drought treatment both in a ZmPRX1 overexpression line and a mutant *** higher root lignin accumulation and seedling survival rate of the overexpression line than that of the wild type or mutant support a role for ZmPRX1 in maize drought tolerance by regulating root development and ***,yeast one-hybrid,Dule luciferase and ChIP-qPCR assays showed that ZmPRX1 is negatively regulated by a nuclear-localized ZmWRKY86 transcription *** gene could potentially be used for breeding of drought-tolerant cultivars.

关键词： Drought tolerance Maize ZmPRX1 Root development Lignin biosynthesis

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四种湍流模型对空化流动模拟的比较

水科学进展 2006年第2期17卷 203-208页

作者：钱忠东黄社华武汉大学水利水电学院水资源与水电工程科学国家重点实验室湖北武汉430072

采用四种湍流模型对NACA66水翼空化流动进行模拟,分析了不同湍流模型和壁面函数对空化流动模拟结果的影响。分析结果表明:ASM模型和RNGk-ε模型对空化数不敏感,且计算精度较高;Realizablek-ε模型对空化数的变化很敏感,对不同的空化数... 详细信息

采用四种湍流模型对NACA66水翼空化流动进行模拟,分析了不同湍流模型和壁面函数对空化流动模拟结果的影响。分析结果表明:ASM模型和RNGk-ε模型对空化数不敏感,且计算精度较高;Realizablek-ε模型对空化数的变化很敏感,对不同的空化数计算精度相差很大;标准k-ε模型对空化数不敏感,但精度不高。增强壁面函数法对空化数不敏感,计算精度较高;标准壁面函数法和非平衡壁面函数法对空化数有一定的敏感性,但计算结果差异不大。

关键词：空化湍流模型壁面函数数值模拟