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Science Bulletin 2024年第5期69卷 661-670页

作者：陈求稳陈宇琛林育青张建云倪晋仁夏军肖琳冯韬马宏海 State Key Laboratory of Hydrology-water Resources&Hydraulic Engineering Nanjing Hydraulic Research InstituteNanjing 210029China Center for Eco-Environment Research Nanjing Hydraulic Research InstituteNanjing 210029China Yangtze institute for Conservation and Green Development Nanjing 210024China School of the Environment Nanjing UniversityNanjing 210008China The Key Laboratory of water and Sediment Sciences Ministry of EducationPeking UniversityBeijing 100091China State Key Laboratory of water Resources and hydropower Engineering Sciences Wuhan UniversityWuhan 430072China

River damming is believed to largely intercept nutrients,particularly retain more phosphorus(P)than nitrogen(N),and thus harm primary productivity,fishery catches,and food security downstream,which seriously constrain global hydropower development and poverty relief in undeveloped regions and can drive geo-political disputes between nations along trans-boundary *** this study,we investigated whether reservoirs can instead improve nutrient regimes *** measured different species of N and P as well as microbial functions in water and sediment of cascade reservoirs in the upper Mekong River over 5 years and modelled the influx and outflux of N and P species in each *** partially retaining total N and total P,reservoirs increased the downstream flux of ammonium and soluble reactive phosphorus(SRP).The increase in ammonium and SRP between outflux and influx showed positive linear relationships with the hydraulic residence time of the cascade reservoirs;and the ratio of SRP to dissolved inorganic nitrogen increased along the reservoir *** lentic environment of reservoirs stimulated algae-mediated conversion of nitrate into ammonium in surface water;the hypoxic condition and the priming effect of algae-induced organic matter enhanced release of ammonium from sediment;the synergy of microbial phosphorylation,reductive condition and sediment geochemical properties increased release of *** study is the first to provide solid evidence that hydropower reservoirs improve downstream nutrient bioavailability and N-P balance through a process of retention-transformation-transport,which may benefit primary *** findings could advance our understanding of the eco-environmental impacts of river damming.

关键词： River damming Biogeochemical cycle Nitrogen Phosphorus Ecological impacts

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Effects of fracture evolution and non-Darcy flow on the thermal performance of enhanced geothermal system in 3D complex fractured rock

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International Journal of Mining Science and Technology 2024年第4期34卷 443-459页

作者： Yachen Xie Jianxing Liao Pengfei Zhao Kaiwen Xia Cunbao Li Department of Civil and Mineral Engineering University of TorontoToronto M5S1A4Canada College of water Resources and hydropower Sichuan UniversityChengdu 610225China State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsWuhan 430071China College of Civil Engineering Guizhou UniversityGuiyang 550025China institute of Geosafety School of Engineering and TechnologyChina University of GeosciencesBeijing 100083China State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering Shenzhen UniversityShenzhen 518060China

In fractured geothermal reservoirs,the fracture networks and internal fluid flow behaviors can significantly impact the thermal *** this study,we proposed a non-Darcy rough discrete fracture network(NR-DFN)model that can simultaneously consider the fracture evolution and non-Darcy flow dynamics in studying the thermo-hydro-mechanical(THM)coupling processes for heat extraction in geothermal *** further employed the model on the Habanero enhanced geothermal systems(EGS)project located in ***,our findings illustrate a clear spatial-temporal variation in the thermal stress and pressure perturbations,as well as uneven spatial distribution of shear failure in 3D fracture *** shear failure is mainly concentrated in the first fracture ***,channeling flow have also been observed in DFNs during heat extraction and are further intensified by the expansion of fractures driven by thermal ***,the combined effect of non-Darcy flow and fracture evolution triggers a rapid decline in the resulting heat rate and *** NR-DFN model framework and the Habanero EGS's results illustrate the importance of both fracture evolution and non-Darcy flow on the efficiency of EGS production and have the potential to promote the development of more sustainable and efficient EGS operations for stakeholders.

关键词： Coupled THM model Non-Darcy flow Deformable DFN Enhanced geothermal systems

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Ski-jump trajectory based on take-off velocity

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Journal of Hydrodynamics 2016年第1期28卷 166-169页

作者：吴建华许准姚莉马飞 College of water conservancy and hydropower Engineering Hohai University College of water conservancy and Ecological Engineering Nanchang Institute of Technology

The theoretical method estimating ski-jump trajectory was paid attention to and modified. The present method is based on the effects of the take-off velocity and the angle in the sensitivity analysis of parameters. The experiments are conducted for a triangular-shaped flip bucket in order to reveal the relationships between the take-off velocity and its influencing factors. The results show that, the take-off velocity has a much larger effect on the impact point than the take-off angle. The take-off velocities of both upper and lower trajectories are all functions of the approach flow Froude number, the deflector height and the deflection angle, especially, the results of the deflection angle of 25° could be directly used when this angle is larger than 25° Meanwhile, this method is checked and the maximum relative errors of both U calx and L_（calx） are 5.1% and 5.6%, respectively.

关键词： trajectory triangular-shaped flip bucket take-off velocity sensitivity analysis of parameters

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A Siltation Simulation and Desiltation Measurement Study Downstream of the Suzhou Creek Sluice, China

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China Ocean Engineering 2013年第6期27卷 781-793页

作者：季永兴杨绯张汉云卢永金 College of water conservancy and hydropower Engineering Hohai University Shanghai water Engineering Design and Research institute

The Suzhou Creek Sluice is currently the largest underwater plain gate in the world, with a single span of 100 m. It is located in a tidal estuary at the junction of the Huangpu River and Suzhou Creek in Shanghai, China. In this study, physical and 2D vertical mathematical models were used to investigate and distinguish the mechanism of siltation downstream of an underwater plain gate from that of other gates types. According to quantitative data obtained by site investigation and the application of the physical hydrodynamic models, it was found that the characteristics of the tidal estuary as well as the fact that the sluice span is equal to the creek width are the major reasons contributing to siltation. A possible desiltation treatment system is proposed for the underwater plain gate. The system includes selection of a suitable location that allows the determination of a reasonable top elevation of the sluice floor, reserving sufficient space under the gate to accommodate siltation, setting up a mechanical desiltation system, and flushing silt along with overflow over the top of the gate. Furthermore, on-site hydraulic silt flushing experiments and a topography survey were conducted. These results showed that the measurement system is effective, and by maintaining this scheduled operation once a month, the downstream riverbed has been maintained in a good condition.

关键词： tidal estuary underwater plain gate siltation sluice Suzhou Creek

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Application of modified discontinuous deformation analysis to dynamic modelling of the Baige landslide in the Jinsha River

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Journal of Mountain Science 2024年第7期21卷 2305-2319页

作者： XIE Chenxi DENG Jianhui PENG Xinyan YANG Zhongkang ZHAO Siyuan LI Hua State Key Laboratory of Hydraulics and Mountain River Engineering College of Water Resource and HydropowerSichuan UniversityChengdu 610031China State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of TechnologyChengdu 610051China MOE Key Laboratory of Deep Earth Science and Engineering Institute for Disaster Management and ReconstructionSichuan UniversityChengdu 610031China Power China Chengdu Engineering Corporation Limited Chengdu 610031China

Accurate dynamic modeling of landslides could help understand the movement mechanisms and guide disaster mitigation and *** deformation analysis(DDA)is an effective approach for investigating ***,DDA fails to accurately capture the degradation in shear strength of rock joints commonly observed in high-speed *** this study,DDA is modified by incorporating simplified joint shear strength *** on the modified DDA,the kinematics of the Baige landslide that occurred along the Jinsha River in China on 10 October 2018 are *** violent starting velocity of the landslide is considered *** cases with different violent starting velocities are investigated to show their effect on the landslide movement ***,the landslide movement process and the final accumulation characteristics are analyzed from multiple *** results show that the violent starting velocity affects the landslide motion characteristics,which is found to be about 4 m/s in the Baige *** movement process of the Baige landslide involves four stages:initiation,high-speed sliding,impact-climbing,low-speed motion and *** accumulation states of sliding masses in different zones are different,which essentially corresponds to *** research results suggest that the modified DDA is applicable to similar high-level rock landslides.

关键词： Discontinuous deformation analysis(DDA) Baige landslide Violent starting velocity movement process Accumulation characteristics

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Influence of flow field on stability of throttled surge tanks with standpipe

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Journal of Hydrodynamics 2013年第2期25卷 294-299页

作者：安建峰张健俞晓东陈胜 College of water conservancy and hydropower Engineering Hohai University

The steady-state flow field characteristics have important effects on the stability of the throttled surge tank with the standpipe. This paper analyzes these effects on the basis of the numerical simulation of the flow field by using the Computational Fluid Dynamics （CFD） method. It is shown that the anticlockwise recirculation zone is formed in the standpipe, which affects the local head loss at the junction of the standpipe with the pipeline. The variation of the head loss coefficient at the junction is linearly related with the diameter ratio of the standpipe to the pipeline. The dimensionless recirculation flow rate is proportional to the square of the diameter ratio. Considering the effects of the recirculation zone, an empirical expression of the critical stability area is obtained. Comparing with the Thoma critical area, the area obtained by the present method is smaller, and the reduction depends on the diameter ratio and the ratio of the velocity head to the head losses in the tunnel. words：

关键词： critical stability area throttled surge tank Computational Fluid Dynamics (CFD) simulation turbulence model flow field

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Production of the C/TiO_(2)composite with a high-performance electrochemical property from titanium-rich sludge via in-situ C coating

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Journal of Environmental Sciences 2024年第3期137卷 131-143页

作者： Hualong Wu Yanxia Zhao Jiexi Wang Xiaoyan Li Kaimin Shih Xuguang Li Wei Liu School of water conservancy and Environment University of JinanJinan 250022China State Key Lab of Physical Chemistry of Solid Surface Collaborative Innovation Center of Chemistry for Energy MaterialsCollege of MaterialsXiamen UniversityXiamen 361005China School of Metallurgy and Environment Central South UniversityChangsha 410083China Department of Civil Engineering The University of Hong KongPokfulamHong KongChina institute of Environment and Ecology Tsinghua Shenzhen International Graduate SchoolTsinghua UniversityShenzhen 518055China

Resource recycling from waste-water and sludge is an important part of the 14th Five-Year Plan in *** emerging titanium-based coagulants have drawn growing attentions due to their strong coagulation capability in water purification and value-added Ti-loaded sludge *** and recovery of the high value-added sludge into functional nanomaterials is highly significant for both sludge reduction and environmental *** present study was carried out to investigate the recycle of the coagulated Ti-loaded sludge to produce functional C/TiO_(2)composites as the anode materials for lithium-ion batteries(LIBs).It is the first time that the application of the Ti-loaded wastewater sludge derived C/TiO_(2)was evaluated for *** experimental results showed that the carbon coating through in-situ carbonization of the sludge produced the C/TiO_(2)composites with a high specific surface area,stable structural integrity,and excellent electrochemical properties that would facilitate Li+diffusion in long-term LIBs *** C/TiO_(2)composites calcinated from the polytitanium sulfate-coagulated sludge at 800℃(N_(2))exhibited the best electrochemical performance during the cycling tests(601 m Ah/g at 100 m A/g after 200 cycles).The research work demonstrates the promising prospect of the recycle and value-added utilization of the Ti-loaded sludge in the production of high-performance C/TiO_(2)composites for energy storage *** study provides a new way for the management and reuse of Ti-loaded waste-sludge.

关键词： Sludge recovery Ti-loaded sludge In-situ coating Lithium-ion battery

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Influence of bending rigidity of submerged vegetation on local flow resistance

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Journal of Hydrodynamics 2014年第2期26卷 242-249页

作者：吴龙华杨校礼 College of water conservancy and hydropower Engineering Hohai University

The different state of the submerged vegetation has different influences on the flow resistance. This paper explores the relationship between the state and the resistance of an individual submerged vegetation, and the relative bending rigidity of the submerged vegetation is determined by the state of the submerged vegetation. Based on the experimental observations, the state and the resistance of an individual submerged vegetation are analyzed under different inflow conditions. At the same time, the influences of the various submerged vegetations on the flow resistance are discussed under the same inflow conditions. Some interesting relationships are obtained between the flow resistance and the relative bending rigidity of the submerged vegetation, and it is shown that the flow resistance increases with the increase of the relative bending rigidity of the submerged vegetation, and they are positively correlated.

关键词： individual submerged vegetation relative bending rigidity local flow resistance

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Large-eddy simulation of suspended sediment transport in turbulent channel flow

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Journal of Hydrodynamics 2013年第1期25卷 48-55页

作者： ZHU Hai WANG Ling-ling TANG Hong-wu College of water conservancy and hydropower Engineering Hohai University

The numerical simulation of the non-cohesive sediment transport in a turbulent channel flow with a high concentration is a challenging but practical task. A modified coherent dynamic eddy model of the Large Eddy Simulation （LES） with a pick-up function is used in the present study to simulate the sediment erosion and the deposition in a turbulent channel flow. The rough wall model is used instead of the LES with the near-wall resolution to obtain the reasonable turbulent flow characteristics while avoiding the high costs in the computation. Good results are obtained, and are used to analyze the sediment transport properties. The results show that the streamwise vortices play an important role in the riverbed erosion and the sediment pick-up, which may serve as guidelines for the sediment management and the water environment protection engineering.

关键词： Large Eddy Simulation (LES) sediment suspension pick-up function turbulent channel flow

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Fin characteristics of aerator devices with lateral deflectors

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Journal of Hydrodynamics 2013年第2期25卷 258-263页

作者：吴建华李丹马飞钱尚托 College of water conservancy and hydropower Engineering Hohai University

The fins will be formed if the lateral deflectors in the side-walls with a bottom aerator device are improperly designed, and the flow regime downstream of the aerator device will be worsened. In this paper, the height and the length of the fins induced by the lateral deflectors are theoretically analyzed along with their influencing factors, and the fin characteristics are experimentally investigated on the basis of the theoretical analysis. It is shown that the intensities of the fins are strongly dependent on the ratio of the lateral cavity length to the bottom cavity length, and other factors, like the working head, the height and the angle of the lateral deflector, the flow Froude number around the aerator device, affect the fins indirectly through the changes of the lateral cavity length. When an aerator device with lateral deflectors is designed, it is crucial to match the above mentioned ratio, and to make the ratio of the two cavity lengths less than 1.0 in order to avoid the generation of the fins.

关键词： aerator cavity length fin lateral deflector

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