通讯机构：
[Yao, Y ] C;Changsha Univ Sci & Technol, Sch Hydraul & Environm Engn, Changsha 410114, Peoples R China.
关键词：
Acoustic wave propagation;Multi-fluids;Weak-form meshfree method;Penalty function method;Continuity condition
摘要：
In this work, we focus on the derivation of the weak-form for meshfree methods in analyzing the time-domain acoustic wave propagation in multi-fluids. Due to the employment of meshfree shape functions not restricted to a local background cell, the continuity condition for acoustic particle velocity cannot be spontaneously satisfied, leading to inaccurate simulations of acoustic wave upon the interface. Thus, the penalty function method is utilized here in the weak-form for meshfree methods in order to cure this discontinuity issue without introducing any addition degrees of freedom. By conducting a number of numerical analyses, the numerical results obtained from a radial point interpolation meshfree method are in accord with the analytical solutions and the numerical results of bilinear and quadratic finite elements, validating the effectiveness of the weak-form derived for meshfree methods. Moreover, the numerical accuracy of the used meshfree method can surpass those of bilinear and quadratic finite elements when the same sets of nodes are employed, especially for relatively high frequencies.
摘要：
Microplastics (MPs) have attracted much attention in recent years, due to the difficulty of degradation and threats to ecological systems and humans. Based on the analysis of 1429 articles on MPs in soil, we found that we know little about the behavior and fate of manure-born MPs from the livestock and poultry production systems to agriculture soils. This review summarizes the analytical methods for sampling, separation, and identification and the occurrence of MPs in livestock and poultry manure, mainly based on 7 surveys related to manure-born MPs. Then, the sources, fate, and environmental risks of MPs in livestock and poultry manure are discussed. MPs, heavy metals, pathogens, antibiotic resistance genes, and persistent organic pollutants are common pollutants in livestock and poultry manure. Worse, manure-born MPs will become smaller, rougher, and more numerous and could easily form more toxic compound pollution after complicated processes of manure treatment, which seriously threatens agricultural soil safety. Finally, an outlook is offered for future research. We hope this article to attract attention to the risks of MPs in livestock and poultry manure and provide a reference for future research.
作者机构：
School of Hydraulic and Environmental Engineering, Changsha University of Science & Technology, Changsha 410114, China;Key Laboratory of Water-Sediment Sciences and Water Disaster Prevention of Hunan Province, Changsha 410114, China;[Changzheng Shi; Hegao Wu] State Key Laboratory of Water Resources Engineering and Management, Wuhan University, Wuhan 430072, China;[Xiangmin Yu] School of Mechanics and Engineering Science, Shanghai University, Shanghai 200444, China;[Jinhong Yu; Jiahao Zhan] School of Hydraulic and Environmental Engineering, Changsha University of Science & Technology, Changsha 410114, China<&wdkj&>Key Laboratory of Water-Sediment Sciences and Water Disaster Prevention of Hunan Province, Changsha 410114, China
通讯机构：
[Jinhong Yu] S;School of Hydraulic and Environmental Engineering, Changsha University of Science & Technology, Changsha 410114, China<&wdkj&>Key Laboratory of Water-Sediment Sciences and Water Disaster Prevention of Hunan Province, Changsha 410114, China
摘要：
Buried flexible pipes are widely employed to transport water, however, its existing structural calculation methods are significantly underestimation both pipe weight and water weight. This study has developed the Spangler model and proposed an innovative calculation method for pipes using theoretical analysis, which takes into account various load effects that arise from different conditions, including empty pipe, water filling, and normal. Furthermore, the applicability of the proposed method has been extensively investigated. The results illustrate that the innovative calculation method integrates the pipe weight and water weight, and pipe deformation by this method exhibits a positive association with the pipe diameter and wall thickness, consistent with FE analysis. The proposed method demonstrates broad applicability, providing improved precision for large-diameter pipes at commonly encountered buried depths. It is imperative not to overlook the self-weight load on large-diameter and shallow-buried pipes, as induces an increased deformation up to 20%. However, the pipe weight can be ignored in cases where the pipe diameter is smaller than 1 m or a buried depth exceeds 4 m. Furthermore, the influence of water weight on pipe deformation exhibits a growing prominence as the diameters expand, resulting in an augmentation of up to 37%.
作者：
Schmidt, Falko;Menendez, Javier;Konietzky, Heinz;Jiang, Zhongming;Fernandez-Oro, Jesus M.;...
期刊：
Journal of Energy Storage,2024年78:110055 ISSN：2352-152X
通讯作者：
Fernández-Oro, JM
作者机构：
[Menendez, Javier] Sadim Engn, Min & Civil Dept, Oviedo 33005, Spain.;[Konietzky, Heinz] TU Bergakad Freiberg, Geotech Inst, D-09599 Freiberg, Germany.;[Jiang, Zhongming] Changsha Univ Sci & Technol, Sch Hydraul Engn, Changsha 410114, Peoples R China.;[Fernandez-Oro, Jesus M.; Fernández-Oro, JM] Univ Oviedo, Energy Dept, Gijon 33271, Spain.;[Alvarez, Laura; Bernardo-Sanchez, Antonio] Univ Leon, Dept Min Technol Topog & Struct, Leon 24071, Spain.
通讯机构：
[Fernández-Oro, JM ] U;Univ Oviedo, Energy Dept, Gijon 33271, Spain.
关键词：
Closed coal mine;Energy storage;CAES;Underground reservoir;Feasibility study
摘要：
In this paper, four mining levels in a closed coal mine in the Asturian Central Coal Basin (NW Spain) have been selected as a case study to investigate the technical feasibility of underground compressed air energy storage systems. First, in order to determine the suitable level and type of concrete lining, a numerical model has been established to analyze the geomechanical performance considering air pressures of 6, 10, 20 and 25 MPa and three different embodiments of concrete lining. Then, another numerical model is used to study the coupled thermo-mechanical performance at level 3, considering 100 operation cycles between 6 and 10 MPa air pressure using a circular concrete lining with a 20 mm thick sealing layer. The results obtained indicate that the deformations are lower at levels 1 and 3, where the shales are located at the top of the coal seam. Deformations and tensile stresses are significantly reduced when a circular concrete lining is used. As the thermal analysis shows, temperature fluctuations are restricted to sealing layer and concrete lining and do not reach the rock mass itself. Therefore, negligible deformations are produced by the effect of temperature compared to the effect of air pressure. Maximum tensile stress and total displacements during the operation occur at the top of the mining drift and reach 9.5 MPa and 3.6 mm, respectively. A technical feasibility can be achieved using a circular concrete lining with a suitable reinforcement system.
摘要：
The dredging of reef-flat sand for engineering construction is a common activity on some Asia-Pacific reef islands, which attract increasing concerns in the community of coastal hazard mitigation. Comparing to the well -studied one-dimensional horizontal (1DH) fringing reefs with excavation pit on the reef flat, little is known about such wave characteristics as sea and swell (SS) waves, infragravity (IG) waves, wave-induced setup and wave -driven current in a two-dimensional horizontal (2DH) fringing reef configuration with the reef-flat pit. To remedy this research gap, a 2DH numerical model according to a set of Boussinesq equations is proposed in this study. The 1DH form of used model is firstly verified with a wave flume experiment based on SS wave height, IG wave height and wave setup along the 1DH reef profile with and without the pit, then its 2DH form is verified by a wave basin experiment in view of both wave and mean current processes in a reef-lagoon-channel system. A comparison between 1DH and 2DH reef configurations with pit is also conducted to further validate the 2DH model. Subsequently, the model is adopted to investigate the effect of excavation pit on these wave processes, particularly for the wave-driven current, in the 2DH reef configuration. The present model is finally used to examine the influences of incident wave conditions and pit morphological features on the wave characteristics in the 2DH reef environment.
关键词：
Hemispherical bed surface;Observed particle;Interference particle;Dispersive pressure;Incipient velocity
摘要：
The sediment particles play a huge role in shaping the bed load transport. In this research, 240 watertunnel experiments are carried out to investigate the incipient velocity of the observation particles in two particle arrangements. To accurately predict the incipient velocity of the observation particles, the equation is conceived by the rolling instability mechanism. The incipient velocity equations and experimental data are used to analyze the trend of dispersive pressure and the effect of arrangement position on velocity. We find that it is appropriate to choose the coefficient of drag as 0.261 and the coefficient of lift as 0.198 for the incipient velocity equation of spherical particles on the hemispherical bed surface. Furthermore, the dispersive pressure is closely related to the flow state, particle size, and particle arrangement, which leads to the incipient velocity of the observation particle being at a minimum when the interference particle angle is 45 degrees. Finally, the particle spacing and the projected area changed with the arrangements, directly affecting the incipient velocity of the observed particle. The analysis of four aspects for the coefficients, dispersive pressure, different particle spacing, and projected area will facilitate the prediction of particle incipient velocity, especially on hemispherical beds. (c) 2023 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.
摘要：
The utilization of municipal sludge as a seed sludge for initiating the autotrophic nitrogen removal (ANR) process presents a challenge due to the negligible abundance of anaerobic ammonia-oxidizing bacteria (AnAOB). Here, a computational fluid dynamics model was used to simulate sludge volume fraction and sludge particle velocity. A high-height-to-diameter-ratio airlift inner-circulation partition bioreactor (HHAIPBR) was operated for 175 d to enrich AnAOB from municipal sludge, and the performance of the ANR process was investigated. The start-up period of HHAIPBR inoculated with municipal sludge required approximately 69 d. A high nitrogen removal performance, with a mean total nitrogen removal efficiency of 82.1%, was obtained for 1 month. The simulation results validated the presence of sludge circulation and revealed the distribution characteristics of dissolved oxygen inside the reactor, further supporting the promotion of sludge granulation via the high height-to-diameter ratio. Nitrosomonas (3.31%) of Proteobacteria and Candidatus Brocadia (6.56%) of Planctomycetota were dominant in the HHAIPBR. This study presents a viable approach for the industrial cultivation of anammox sludge and the rapid start-up of the partial nitritation-anammox system.
通讯机构：
[Chen, J ] C;Changsha Univ Sci & Technol, Sch Hydraul & Environm Engn, Changsha 410114, Peoples R China.;Key Lab Dongting Lake Aquat Ecoenvironm Control &, Changsha 410114, Peoples R China.;Key Lab Water Sediment Sci & Water Disaster Preven, Changsha 410114, Peoples R China.
关键词：
reef islands;coral sand beach;equilibrium beach profile;coral sand bar
摘要：
This study utilized 50 laboratory experiments to document the evolution of coral beaches under varying regular wave conditions, including five distinct wave periods and ten wave heights. Both the type of equilibrium beach and the shape of sand bars were used to represent beach evolution. The evolution of coral sand beaches was then compared to quartz sand beaches. The experimental results show that the predicted (modeled) equilibrium profile of a quartz sand beach was not applicable to coral sand beaches. Compared to sand bars on quartz sand beaches, the distance from bar crests to the beach berm in coral sand beaches was greater, whereas the erosional depth of sand troughs was deeper. However, the grain size distribution of sand associated with the coral sand beach under wave action was consistent with Celikoglu’s law. Both an equilibrium beach profile classification model and a sand bar shape prediction model for coral sand beaches were developed based on the experimental data.
作者机构：
[Huang, Binbin; Lei, Xiaojia; Wang, Xuxu] Hunan Univ, Coll Environm Sci & Engn, Changsha 410082, Peoples R China.;[Chen, Wenqian] Natl Univ Singapore, Dept Pharm, S9, 4 Sci Dr 2, Singapore 117544, Singapore.;[Lei, Chao] Changsha Univ Sci & Technol, Sch Hydraul Engn, Changsha 410114, Peoples R China.;[Zhu, Nengwu; Huang, Binbin; Zhu, NW] South China Univ Technol, Sch Environm & Energy, Key Lab Pollut Control & Ecosyst Restorat Ind Clus, Minist Educ, Guangzhou 510006, Peoples R China.
通讯机构：
[Huang, BB ] H;[Zhu, NW] S;Hunan Univ, Coll Environm Sci & Engn, Changsha 410082, Peoples R China.;South China Univ Technol, Sch Environm & Energy, Key Lab Pollut Control & Ecosyst Restorat Ind Clus, Minist Educ, Guangzhou 510006, Peoples R China.
关键词：
p-block elements;Acetylene hydrochlorination;Structure-property relationship;Activity and stability;Performance descriptor;Theoretical calculation
摘要：
Catalytic acetylene hydrochlorination has been extensively applied in the production of vinyl chloride, which is the building block of polyvinyl chloride, the third most produced polymer in the world. Achieving high performance with non-mercury catalysts (e.g., Au-based catalysts) has significant industrial relevance. The substitution of mercury-based catalysts with p-block element-regulated catalysts has become a mainstream practice, attracting extensive investigations over the past years. The doping of p-block elements can address the fundamental problems of catalyst deactivation and low atom utilization efficiency, resulting in the formation of stabilized ultrafine metal nanoparticles or even single-atom forms, which shows superior catalytic performance towards acetylene hydrochlorination. Herein, based on the recent advances in theoretical and experimental works, we provide a comprehensive review on the progress of the synthesis, properties, performances and mechanisms of p-block element-regulated catalysts for acetylene hydrochlorination. The synthesis methods and the critical factors for preparing p-block element-regulated catalysts are described to highlight their effects on catalytic performance. The relationships of catalyst structures with catalytic activity and stability are critically discussed to highlight the critical factors for designing catalysts. Theoretical calculations are conducted to compare and uncover the effects of different p-block elements on the properties and performances of graphene-based materials as model catalysts. Finally, the development trend of p-block element-regulated catalysts is discussed to forecast future directions. The insights into the performance enhancement mechanisms and the structure-property relationships can shed some light on the directional synthesis of materials to realize better practical applications for acetylene hydrochlorination.
摘要：
Due to rapid development, the occurrence of flood has become more and more frequent. However, due to the complex nature and limited knowledge, the conventional hydrological model for flood forecasting purposes faces drawbacks in terms of technical difficulties. Hence, it is essential to have a model which can provide a considerably high level of accuracy for flood forecasting. This study selected the area between the Xiangtan station and Changsha station, located in Xiangjiang River as the study area. Recurrent neural network (RNN), gated recurrent unit (GRU) and long short-term memory (LSTM) were applied for model development purposes. The models were used to forecast the flood disasters occurring in 2017, 2019, 2020 and 2022 for 1h, 6h and 12h in advance. A series of statistical analyses have been conducted to evaluate the model performance. The LSTM model outperformed than the RNN and GRU models. In terms of the overall analysis, the LSTM model achieved relatively good accuracy with a NSE of above 0.98, and RMSE of lower than 0.2 m. In addition, the model with a 6h in advance is the most suitable model to predict the peak flood arrival time with an absolute error of less than 3 hours.
作者机构：
[Yao, Zhen; Bian, Cheng; Jiang, Changbo; Wu, Zhiyuan; Chen, Jie; Liu, Jiaxiang] Changsha Univ Sci & Technol, Sch Hydraul & Environm Engn, Changsha 410114, Peoples R China.;[Jiang, Changbo; Wu, Zhiyuan; Chen, Jie] Key Lab Dongting Lake Aquat Ecoenvironm Control &, Changsha 410114, Peoples R China.;[Jiang, Changbo; Wu, Zhiyuan; Chen, Jie] Key Lab Water Sediment Sci & Water Disaster Preven, Changsha 410114, Peoples R China.
通讯机构：
[Jie Chen] S;School of Hydraulic and Environmental Engineering, Changsha University of Science & Technology, Changsha, 410114, China<&wdkj&>Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, Changsha, 410114, China<&wdkj&>Key Laboratory of Water-Sediment Sciences and Water Disaster Prevention of Hunan Province, Changsha, 410114, China
关键词：
Coral sediment;Oscillatory flow;Threshold of motion;Shields parameters;Critical near-bottom peak velocity
摘要：
In this study, the incipient motion thresholds of coral sediment with the action of oscillatory currents were experimentally recorded by conducting a total of 405 laboratory experiments, including an analysis of nine sieve median diameters, five water depths, and four wave periods. The coral sediment Shields parameters for oscillatory flow were compared to those for unidirectional flow and to those of shell Shields parameters for oscillatory flow. The results showed that there was an extensive scatter range in the Shields parameter for oscillatory flow of coral sediments. Additionally, the coral sediment Shields parameter for oscillatory flow was slightly different from that for unidirectional flow. The use of the Shields curve form to represent the coral sediment threshold for oscillatory flow was not appropriate. Using the critical near-bottom peak velocity to represent the incipient motion threshold of coral sediment for oscillatory flow was a better option. The use of experimental particle data analyses and the equation for the critical near-bottom peak velocity of quartz sand for oscillatory flow was modified to obtain a critical near-bottom peak velocity equation for coral sediment. This equation adds the influence of shape through the median Corey shape factor.
摘要：
The reef-lagoon-channel system is very typical on the low-lying reef-lined coasts in tropical and subtropical areas. Comparing to the well-studied one-dimensional horizontal (1DH) fringing reefs, little is known about the alongshore wave runup variation and its implication for coastal flooding in such a two-dimensional horizontal (2DH) reef configuration. To better understand the wave processes in an idealized reef-lagoon-channel system, a numerical model is presented in this study, which is based on a set of fully nonlinear Boussinesq equations. Wave breaking is addressed by a shock-capturing scheme and bottom friction is formulated by the Manning frictional law. The adopted model is first validated by a published laboratory dataset in view of wave spectrum, wave height, wave setup, mean current as well as wave runup on the back-reef beach. Subsequently, the effects of hydrodynamic (incident wave height, incident wave period, reef-flat wave level) and reef morphological (fore-reef slope, cross-shore reef-flat width, channel width and frictional coefficient) parameters that are not fully considered by the laboratory experiments are investigated through the numerical simulations. Finally, the model is used to analyze the infragravity (IG) wave resonant modes in the system, and the effects of channel on such modes are also demonstrated.
作者机构：
[Li, Yi] Hubei Univ Technol, Sch Civil Engn Architecture & Environm, Wuhan 430068, Peoples R China.;[Liu, Yaning] Univ Colorado Denver, Dept Math & Stat Sci, Denver, CO 80204 USA.;[Li, Yi] Changsha Univ Sci & Technol, Sch Hydraul Engn, Changsha 410114, Peoples R China.;[Hu, Bin] Chinese Acad Sci, Key Lab Drinking Water Sci & Technol, Res Ctr Ecoenvironm Sci, Beijing 100085, Peoples R China.;[Hu, Bin] Univ Chinese Acad Sci, Beijing 100049, Peoples R China.
通讯机构：
[Li, Y ] C;Changsha Univ Sci & Technol, Sch Hydraul Engn, Changsha 410114, Peoples R China.
关键词：
Compressed air energy storage in aquifers;Shallow aquifer;Highly permeable leakage path;Wellbore-reservoir model;Brine and air leakage
摘要：
The potential leakage influences of compressed air energy storage in aquifers, especially on the overlying shallow aquifer environment, need more attention, but there is still a lack of relevant studies. In this research, a coupled wellbore-reservoir underground anticline model is simulated using T2Well/EOS3. Two-phase non-Darcy flows, different from the multiphase Darcy flow in porous media, are considered in both the central working wellbore and a highly permeable leakage path. In an anticline, the results show that the leakage rate will decline and reach a relatively steady state as the cycles continue. The final continuous small periodic oscillations of leakage rate occur with a hysteresis effect with respect to cycle injection-production. When air leakage occurs in the initial gas bubble process, it gradually disappears and gets replaced by brine leakage. A decrease in the reservoir permeability can result in a larger initial leakage rate, but a smaller rate and fluctuation during the cycle process. However, in a horizontal reservoir, strong gas fingering increases the risk of air leakage, which, once occurs, can last during the rest of the process. This research can deepen the understanding of the leakage process and help evaluate and prevent incidents of environmental contamination in gas storage in aquifers.
