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以发展新质生产力提升水安全保障能力的逻辑机理与关键路径

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中国水利 2024年第8期 1-5页

作者：唐洪武河海大学南京210024

在实现水利高质量发展过程中,“高科技、高效能、高质量”的新质生产力特征已逐渐显现。发展新质生产力、提升水安全保障能力在发展理念、目标指向、实施动力等关键要素上具有内在的逻辑契合性。提升水安全保障能力,需精准对接新质生产... 详细信息

在实现水利高质量发展过程中,“高科技、高效能、高质量”的新质生产力特征已逐渐显现。发展新质生产力、提升水安全保障能力在发展理念、目标指向、实施动力等关键要素上具有内在的逻辑契合性。提升水安全保障能力,需精准对接新质生产力需求,加快实现水利高水平科技自立自强,培养卓越水利科技创新人才,形成与新质生产力相适应的新型生产关系。

关键词：新质生产力水安全高质量发展关键路径机理

核壳结构上转换发光纳米粒子的合成及用于细胞色素C的检测

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分析科学学报 2024年第2期40卷 125-131页

作者：董佳瑶易静刘浏于贺唐宏武武汉大学化学与分子科学学院湖北武汉430072

本工作合成了三层核壳结构的上转换发光纳米粒子,其中第一层是惰性核,第二层为发光层,为了增强上转换发光强度,又在表面包覆了第三层惰性壳层。该材料粒径均一、分散性良好,其发光层厚度约为2.4nm,惰性壳层厚度约为2.9nm。在其表面修饰... 详细信息

本工作合成了三层核壳结构的上转换发光纳米粒子,其中第一层是惰性核,第二层为发光层,为了增强上转换发光强度,又在表面包覆了第三层惰性壳层。该材料粒径均一、分散性良好,其发光层厚度约为2.4nm,惰性壳层厚度约为2.9nm。在其表面修饰了细胞色素C的适配体链及互补链,在适配体的3’端修饰了BHQ3基团,能够猝灭上转换纳米粒子在655nm波长处的发光。当细胞色素C存在时,适配体与细胞色素C结合从而离开其表面,使655nm处的发光恢复。在检测过程中,540nm处的发光强度不会发生变化,可以用作细胞色素C的比率荧光检测。结果表明,当细胞色素C浓度在5~80μmol/L范围时,发光信号恢复程度与细胞色素C浓度呈线性相关,相关系数为0.998,检出限为1μmol/L。所建立方法可为细胞色素C的荧光检测提供一种新的技术思路。

关键词：上转换发光纳米粒子细胞色素C 发光共振能量转移

Particle size distribution of bed materials in the sandy river bed of alluvial rivers

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International Journal of Sediment Research 2017年第3期32卷 331-339页

作者： Luohao Zhang hongwu Zhang hongwu tang Chensu Zhao College of Water Conservancy and Hydropower Engineering Hohai University State Key Laboratory of Hydroscience and Engineering Tsinghua University School of Civil and Environment Engineering University of Science and Technology Beijing

The particle size distribution of bed materials in the sandy river bed of alluvial rivers is important in the study of topics such as friction, river bed evolution, erosion, and siltation. It also can reflect the dependency relation between river bed sediment and flow intensity. In this paper, the critical pattern of sediment movement in the near-wall region of a sandy river bed was analyzed. According to the principle of momentum balance, the critical settling-rising condition of bed material in a sandy river bed was found to be instantaneous turbulent velocity equal to 2.7 times the sediment settling velocity in quiescent water. Based on a vertical instantaneous turbulent velocity with a Gaussian distribution, a theoretical relation for calculating the particle size distribution of bed materials in a sandy river bed without pre-known characteristic grain sizes was developed by solving a stochastic equation. The formula is verified using measured data, and the results show that the proposed formula was in accordance with the measured data. This study has theoretical significance and practical value for determining the bed material particle size distribution of the sandy bed of alluvial rivers.

关键词： Particle size distribution Bed material Turbulence Momentum Sandy river bed

Large-eddy simulation of the generation and propagation of internal solitary waves

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Science China(Physics,Mechanics & Astronomy) 2014年第6期57卷 1128-1136页

作者： ZHU Hai WANG LingLing tang hongwu State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai University

A modified large-eddy simulation model,the dynamic coherent eddy model(DCEM)is employed to simulate the generation and propagation of internal solitary waves(ISWs)of both depression and elevation type,with wave amplitudes ranging from small,medium to large *** simulation results agree well with the existing experimental *** generation process of ISWs is successfully captured by the DCEM *** instabilities and diapycnal mixing in the initial wave generation phase are *** dissipation rate is not equal at different locations of an ***-induced velocity field is analyzed in the present *** structure of the bottom boundary layer(BBL)of internal wave packets is found to be different from that of a single ISW.A reverse boundary jet instead of a separation bubble exists behind the leading internal wave while separation bubbles appear in other parts of the wave-induced velocity *** boundary jet flow resulting from the adverse pressure gradients has distinctive dynamics compared with free shear jets.

关键词： ISW DCEM internal wave generation bottom boundary layer LES boundary jets

Clear-water local scouring around three piers in a tandem arrangement

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Science China(Technological Sciences) 2016年第6期59卷 888-896页

作者： WANG Hao tang hongwu XIAO JiangFeng WANG Yao JIANG Sheng State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai University Nanjing 210098 China Huaihe River Commission of the Ministry of Water Resource Bengbu 233001 China

Experiments of local scouring around three piers were carried out under steady clear-water conditions. We investigated the role of pier spacing and flow rate in scour depth and progression. The scour-hole depth around the upstream pier was the same as that for single piers and independent of pier spacing. The scour behavior of the middle and downstream piers progressed through a synchronous scouring region, a transition region, and a radical deviation region as the fluid velocity increased. The critical velocity from the synchronous scouring region to the transition region for the middle and downstream piers was the same, which linearly increased with pier spacing. The degree of deviation in the radical deviation region for the middle and downstream piers was dependent on the pier spacing. The critical velocity from the transition region to the radical deviation region for the middle pier increased with the pier spacing. When the spacing was larger than 11 times the diameter of a pier, the scour depths of the three-pier configuration were the same as for the single piers, which indicates the limit of inter-pier fluid–structure interaction. Finally, the data from this study are used to derive adjustment factors to predict the local scour depth around three piers.

关键词： scouring piers critical velocity fluid-structure interaction

An experimental study of the incipient bed shear stress partition in mobile bed channels filled with emergent rigid vegetation

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Science China(Technological Sciences) 2014年第6期57卷 1165-1174页

作者： WANG Hao tang hongwu YUAN SaiYu LV ShengQi ZHAO XuanYu State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai University

This paper investigates the bed shear stress based on the condition of the incipient motion of sediment in a uniform-flow flume covered with emergent rigid vegetation,which is represented by arrays of circular cylinders arranged in a regular pattern.A total of 148 tests are performed to observe the influence of the vegetation density,bed slope,flow depth and sediment size on the bed shear *** tests reveal that when the sediment is in incipient motion,the resistances acting on the flow passing the rigid vegetation contain the vegetation resistance and the bed shear *** shear stress could be divided into two parts:the grain shear stress and the shear stress caused by sand dunes,which are the deformed bedform with the sediment incipient *** empirical relationship between the shear stress of the sand dune and vegetation density,the Froude number,the apparent vegetation layer velocity is developed.

关键词： open channel flows hydraulic radius incipient motion bed shear stress emergent rigid vegetation

Experimental study of depth-limited open-channel flows over a gravel bed

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International Journal of Sediment Research 2015年第2期30卷 160-166页

作者： Cheng Zeng Chiwai Li hongwu tang Lingling Wang Jingqiao Mao College of Water Conservancy and Hydropower Engineering Hohai University Department of Civil and Environmental Engineering The Hong Kong Polytechnic University

Laboratory experiments of depth-limited open-channel flows over a gravel bed were conducted in the *** gravel patches with identical individual element size and different lengths（3.81 m and 7.5 m）were *** depth-limited uniform flow regime with relative submergence S;（= D/k;） ranging from2.68 to 5.94 was produced by adjusting the tailgate *** velocity profiles were measured by using both an ultra-sound velocity profiler（UVP） and an acoustic Doppler velocimeter（ADV）.The conventional methods used to determine the zero-plane displacement and estimate the bed shear velocity were then reviewed and *** measured double-averaged（DA） velocity profiles were found to fit well with the log law and defect law with a non-universal Karman constant κ./κ-value remains nearly constant and in the range from 0.2 to 0.3 for the long patch（LP） cases and κ-values are scattered within a wider range from 0.3 to 0.5 for the short patch（SP） *** the Br-value in log law remains constant and equal to 8.5 for LP cases,the Br-value was found to decrease with the increase of the dimensionless roughness height k;for SP *** streamwise turbulence intensity distributions were found to be independent on the patch length and agree well with the available experimental data in the intermediate region and wall *** Manning resistance coefficient and Darcy-Weisbach friction factor were *** κ-value decreases to 0.22 for the fitting of the logarithmic flow resistance law under small relative *** value of the integration constant Ar in the logarithmic law falls within the normal range between 3.25 and 6.25.

关键词： Depth-limited open-channel flow Gravel bed D.A velocity profile Karman constant Flow resistance

Swimming behavior of juvenile silver carp near the separation zone of a channel confluence

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International Journal of Sediment Research 2022年第1期37卷 122-127页

作者： Saiyu Yuan Lei Xu hongwu tang Yang Xiao Colin Whittaker State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai University Yangtze Institute for Conservation and Development Department of Civil and Environmental Engineering The University of Auckland

Knowledge of locomotion of fish near river confluences is important for prediction of fish distribution in a river *** flow separation zone near the confluence of a river network is a favorite habitat and feeding place for silver carp,which is one of the four major species of Chinese carp and usually provides positive rheotaxis to water *** the current study,a series of laboratory experiments were done to determine the behavioral responses of juvenile silver carp to the hydrodynamic forces near the separation zone of a channel *** locomotion and trajectory of juvenile silver carp were recorded by infrared thermal imaging,while the flow velocity field near the separation zone was measured by a Particle Image Velocimetry (PIV) system.A total of 60 juvenile silver carp were released near the separation zone among which 40 carp swam in the upstream *** them,24 carp swam to the tributary and the remaining 16 swam into the main *** all these 24 carp travelled initially along the boundary of the separation zone near the corner,where flow shear was strongest,and then swam to the *** of avoiding zones of strong vorticity,they chose and followed a trajectory along which the flow vorticity was *** encountering these vortical flows,they increased the tailbeat frequency and decreased the tail-beat amplitude to maintain body *** observations provide important knowledge on locomotion of fish near river confluences and are beneficial for the fish habitat protection.

关键词： Channel confluence Flow separation Juvenile silver carp Fish locomotion

Impact of the Yellow River capture on the paleoenvironmental changes of Hongze Lake, China

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International Journal of Sediment Research 2023年第4期38卷 503-515页

作者： hongwu tang Ming Gao Saiyu Yuan Huiming Zhang Yang Xiao Fuxin Zhang Kun Zhang State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai University Key Laboratory of Hydrologic-Cycle and Hydrodynamic-System of Ministry of Water Resources Hohai University Institute of Water Science and Technology Hohai University

The Yellow River(YR) capture of the Huai River had a profound effect on the landscape evolution,ecology, and social development in China, disrupting the evolution of some vital shallow floodplain *** of the absence of lacustrine sediment provenance analysis, previous studies were inadequate in distinguishing the influence of YR capture on paleoenvironmental changes in these lakes, especially on landscape evolution, redox conditions, lake level changes, and organic productivity. The current study aims to use X-ray fluorescence-core scanning(XRF-CS) and multivariate statistics on a 9.8 m sediment core from Hongze Lake(HZL), China, to analyze the impact of the YR capture on the lake’s paleoenvironmental changes and the sediment provenance simultaneously. High-resolution images, magnetic susceptibility, and XRF-based multi-element data were obtained using a GEOTEK Multi-Sensor Core Logger. The calcium(Ca) content indicates the presence of YR sediment in HZL, given the high Ca content in YR sediment and the identification of mainly exogenous sources of Ca in HZL. The high values of Ca indicate that 48.7% of the sediment in the center of HZL is related to the YR’s incursion. Periods of higher Ca content coincide with periods of higher oxygenation levels of the lake(as indicated by the ratio of manganese to titanium) and lower organic content in the lake sediment(as indicated by the ratio of incoherent to coherent scatter). These analyses reveal that the YR’s capture of HZL significantly increased the lake’s oxygen level. Furthermore, the decrease in the organic content of sediment tends to be the result of the accelerated deposition caused by the YR. The decrease in Ca content coincides with an increase in lake levels(as indicated by magnetic susceptibility). Thus, it can be inferred that the embankment on the eastern side of HZL, built to increase lake storage, has reduced the incursion frequency of the YR.

关键词： Yellow River capture Paleoenvironmental reconstruction XRF-CS Hongze Lake