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Journal of Environmental Sciences 2024年第4期138卷 46-61页

作者： Guanlong Yu Kai Yang Yi Yang Yifu Li Qifang Sun Peiyuan Li Wenming Wang Fengming Song Tao Ling Xuejun Peng Zhi Yu Shiquan Sun School of hydraulic and Environmental Engineering Changsha University of Science&TechnologyChangsha 410114China Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province Changsha 410114China Hunan Pilot Yanghu Reclaimed Water Co. Ltd.Changsha 410208China China Railway Wuju Group the First Engineering Co. Ltd.Changsha 410117China

It is important to investigate whether combining two modification strategies has a synergistic effect on the activity of *** this manuscript,Fe-doped BiOBr/Bi_(2)WO_(6) heterojunctions were synthesized by a one-pot solvothermal method,and excellent photocatalytic performance was obtained for the degradation of tetracycline hydrochloride(TCH)in water without the addition of *** experiments and characterization,the synergistic effect between Fe ion doping and the BiOBr/Bi_(2)WO_(6) heterojunction was *** Fe/BiOBr/Bi_(2)WO_(6) composite photocatalyst had a beneficial void structure,enhanced visible light response,and could inhibit the recombination of photogenerated support well,which improved the photocatalytic *** presented experiments demonstrate that Fe/BiOBr/Bi_(2)WO_(6) removes 97% of TCH from aqueous solution,while pure BiOBr and Bi_(2)WO_(6) only remove 56% and 65% of TCH,***,the separation and transfer mechanisms of photoexcited carriers were determined in conjunction with the experimental *** study provides a new direction for the design of efficient photocatalysts through the use of a dual co-modification strategy.

关键词： BiOBr/Bi_(2)WO_(6) Fe-doping Dual strategy Tetracycline hydrochloride Photodegradation

A Novel Accurate Method forMulti-Term Time-Fractional Nonlinear Diffusion Equations in Arbitrary Domains

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Computer Modeling in Engineering & Sciences 2024年第2期138卷 1521-1548页

作者： Tao Hu Cheng Huang Sergiy Reutskiy Jun Lu Ji Lin Ningbo Yongxin Engineering Consulting Co. Ltd.Ningbo315042China Taizhou HuanfengWater Conservancy Engineering Co. Ltd.Taizhou318050China A.Pidhornyi Institute of Mechanical Engineering Problems National Academy of Sciences of UkraineKharkiv61046Ukraine Material and Structure department Nanjing Hydraulic Research InstituteNanjing210029China College of Mechanics and Materials Hohai UniversityNanjing211100China

Anovel accuratemethod is proposed to solve a broad variety of linear and nonlinear(1+1)-dimensional and(2+1)-dimensional multi-term time-fractional partial differential equations with spatial operators of anisotropic ***(1+1)-dimensional problems,analytical solutions that satisfy the boundary requirements are *** solutions are numerically calculated using the trigonometric basis approximation for(2+1)-dimensional *** the aid of these analytical or numerical approximations,the original problems can be converted into the fractional ordinary differential equations,and solutions to the fractional ordinary differential equations are approximated by modified radial basis functions with time-dependent *** efficient backward substitution strategy that was previously provided for a single fractional ordinary differential equation is then used to solve the corresponding *** straightforward quasilinearization technique is applied to handle nonlinear *** experiments demonstrate the suggested algorithm’s superior accuracy and efficiency.

关键词： Müntz polynomial basis backward substitutionmethod collocationmethod meshlessmethod fractional equation

Long-Term Extreme Wave Characteristics in the Water Adjacent to China Based on ERA5 Reanalysis Data

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Journal of Ocean University of China 2024年第1期23卷 1-10页

作者： DU Wenyan ZHANG Xuri SHI Hongyuan LI Guanyu ZHOU Zhengqiao YOU Zaijin ZHANG Kuncheng School of hydraulic Engineering Ludong UniversityYantai 264025China Center for Ports and Maritime Safety(CPMS) Dalian Maritime UniversityDalian 1160263China Nation Ocean Technology Center Tianjin 300111China Navigation Guarantee Center of South China Sea(NGCS)MOT Guangzhou Hydrographic Center Guangzhou 510320China Institute of Marine Development/Military Teaching department School of MarxismOcean University of ChinaQingdao 266100China Yantai Kekan Marine Technology Co. Ltd.Yantai 264025China

Extreme waves have a profound impact on coastal infrastructure;thus,understanding the variation law of risky analysis and disaster prevention in coastal zones is *** paper analyzed the spatiotemporal characteristics of extreme wave heights adjacent to China from 1979 to 2018 based on the ERA5 *** extreme value analysis is undertaken in eight repre-sentative points to investigate the trends in the values of 50-and 100-year wave *** show that the mean value of extreme waves is the largest in the eastern part of Taiwan Island and the smallest in the Bohai Sea from 1979 to *** the extreme wave height in the northeastern part of Taiwan Island shows a significant increase trend in the study *** analysis shows remarkable variations in the values of 50-and 100-year significant wave heights in eight *** the annual mean change,E1,E2,S1,and S2 present an increasing trend,while S3 shows a decreasing *** points for the seasonal mean change demon-strate an increasing trend in spring and winter,while other points show a decreasing trend in summer and ***,the E1 point growth rate is large in autumn,which is related to the change in typhoon intensity and the northward movement of the typhoon path.

关键词： extreme wave height NEVA wave climate ERA5 reanalysis

Granulometry Assessment of Lom Pangar Dam Sediments (East-Cameroon)

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Journal of Geoscience and Environment Protection 2024年第6期12卷 207-231页

作者： Rodrigue Fotie Lele Mihaela Amalia Diminescu Issoufou Ouedraogo Annette Madelene Dăncila Souleymane Pelede Alphonse Emadak Martin Lompo department of Geology University Joseph Ki Zerbo Ouagadougou Burkina Faso department of Water and Energy Green Heart International Bafoussam Cameroon department of hydraulic Machineries and Environmental Engineering National University of Science and Technology Politehnica Bucharest Bucharest Romania department of Mining Engineering University Yembila-Abdoulaye-Toguyeni Fada NGourma Burkina Faso department of Inorganic Chemistry University of Yaound I Yaound Cameroon

The Lom Pangar dam, the largest reservoir in Cameroon with a storage capacity of 6 km3 and a 30 MW hydropower plant, primarily regulates the hydrologic regime of the Sanaga River to maintain hydropower efficiency during dry seasons and enhance downstream hydropower plant performance. Understanding and managing sediments are crucial for the sustainability of dams, as indicated by numerous studies. This study assessed the granulometry of the sediments transported across the reservoir. For that purpose, 6 samples of fresh sediments were collected in the lacustrine and transitional sections of the reservoir using the standard method. Particles size was assessed using the laser diffusion technic after a 3 mm sieving. Various granulometric parameters were derived from the literature to analyze and characterize those sediments. Results show that silts are more than 70% of particles size and range between 2.19 - 60.26 µm. Size distribution also shows the same trend with D75 less than 51 µm. This is confirmed by the low values of Inman Skewness SkΦ (−0.168 to 0.303). The Sorting index S0 ranges from 0.31 to 0.53 µm, showing a very well-sorted sediments, aligning with low values of Krumbein index (0.906 - 1.683) that express the low heterometry of the particles. The consequence on the dam will be a quick clogging of the bottom of the reservoir. Their pH varies from 7.0 to 7.5. It also appears that the sandy fraction trend is higher in the right bank of the dam and reaches 22% on the right bank of Pangar River due to crystalline geology. Fraction greater than 3000 µm is negligible. The management of the dam has to keep attention to these results as siltation may close the safety outlet of the dam, damage turbines, and provoke recurrent technical and safety issues. Further, the clogging of the bottom of the reservoir may lead to an ecological problem with the limitation of hyporheic flow. Thus, water exchange with the underground water table and the natural purification of wate

关键词： Lom Pangar Dam Sediments Granulometry Sustainability Hydropower Dam Safety

Frequency and size change of ice–snow avalanches in the central Himalaya:A case from the Annapurna Ⅱ glacier

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Advances in Climate Change Research 2024年第3期15卷 464-475页

作者： Yao LI Yi-Fei CUI Jian-Sheng HAO Zheng-Tao ZHANG Hao WANG Jian GUO Shuo-Fan WANG State Key Laboratory of Hydroscience and Engineering Department of Hydraulic EngineeringTsinghua UniversityBeijing 100084China Key Laboratory of Hydrosphere Sciences of the Ministry of Water Resources Beijing 100084China Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China School of National Safety and Emergency Management Beijing Normal UniversityBeijing 100875China Key Laboratory of Mountain Hazards and Earth Surface Process Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu 610041China

Glaciers have retreated and shrunk in High Mountain Asia since the mid-20th century because of global warming,leading to glacier instability and hazardous iceesnow ***,the complex relationship between iceesnow avalanches and factors such as climate and potential triggers are difficult to understand because of the lack of observational ***,we addressed iceesnow avalanches on the Annapurna Ⅱ glacier in Nepal,Central *** constructed an iceesnow avalanche history using long-term multi-source remote sensing images(1988-2021)and mapped the velocity fields of glaciers using cross-correlation analysis on SAR and optical ***,we investigated the impact of climate change and earthquakes on the frequency and size of iceesnow *** results demonstrate that the frequency of iceesnow avalanches has increased from 10 in 1988 to 27 in 2020,but the average area of iceesnow avalanche deposits has decreased by approximately 70%,from 3.4×10^(5) m^(2) in 1988 to 1.2×10^(5) m^(2) in *** evolutionary characteristic of ice avalanches is linked to the impact of glacier retreat(reduction in ice material supply)and increased activity under climate *** glacier movement velocity controls the size of iceesnow avalanches and can be set as an indicator for iceesnow avalanche *** the Annapurna Ⅱ glacier,an iceesnow avalanche occurred when the glacier velocities were greater than 1.5 m d^(-1).These results offer insights into iceesnow avalanche risk assessment and prediction in high-mountain areas,particularly in regions characterised by dense glacier distribution.

关键词： Iceesnow avalanche Glacier instability Climate change Central Himalaya Remote sensing

Optimal dosing time of acid algaecide for restraining algal growth

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Water Science and Engineering 2013年第4期6卷 402-408页

作者： Cui-chao PANG Xin-jian FAN Jie ZHOU Shi-qiang WU hydraulic Engineering department Nanjing Hydraulic Research Institute

Restraining algal growth by algaecide has been studied by many researchers, but the dosing time has not yet been studied. In this study, we examined the appropriate dosing time of algaecide through a series of experiments. In the experiments, the pH value of water is significantly affected by Microcystis aeruginosa, and the variation of the pH value is in favor of the growth of the alga. Therefore, using acid algaecide in the period with maximum pH values, i.e., the stable phase, would change the acidity-alkalinity of the water significantly, and would negatively affect algal growth. Acid algaecide does not eliminate the alga effectively if the acid algaecide is dosed in the logarithmic growth phase. Using acid algaecide in the decline phase after algal bloom not only is unfavorable for eliminating the alga, but also prolongs the decline phase, and even brings about next larger algal bloom.

关键词： Microcystis aeruginosa," algal bloom," acid algaecide dosing time

Numerical analysis of soil-rock mixture's meso-mechanics based on biaxial test

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Journal of Central South University 2016年第3期23卷 685-700页

作者：张海洋徐文杰于玉贞 State Key Laboratory of Hydroscience and hydraulic Engineering Department of Hydraulic Engineering Tsinghua University

Soil-rock mixture(S-RM)is a widely distributed geotechnical medium composed of "soil" and "rock block" different both in size and strength. Internal rock blocks form special and variable meso-structural characteristics of S-RM. The objective of this work was to study the control mechanism of meso-structural characteristics on mechanical properties of S-RM. For S-RM containing randomly generated polygonal rock blocks, a series of biaxial tests based on DEM were conducted. On the basis of research on the effects of rock blocks' breakability and sample lateral boundary type(rigid, flexible) on macroscopic mechanical behavior of S-RM, an expanded Mohr-Coulomb criterion in power function form was proposed to represent the strength envelop. At the mesoscopic level, the variations of meso-structure such as rotation of rock block, and the formation mechanism and evolution process of the shear band during tests were investigated. The results show that for S-RM with a high content of rock block, translation, rotating and breakage of rock blocks have crucial effects on mechanical behavior of S-RM. The formation and location of the shear band inside S-RM sample are also controlled by breakability and arrangement of rock blocks.

关键词： soil-rock mixture (S-RM) meso-structural mechanics (MSM) discrete element method (DEM) rock block breakability lateral boundary type shear band

Generation of 3D random meso-structure of soil-rock mixture and its meso-structural mechanics based on numerical tests

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Journal of Central South University 2015年第2期22卷 619-630页

作者：徐文杰张海洋介玉新于玉贞 State Key Laboratory of Hydroscience and hydraulic Engineering(department of hydraulic Engineering Tsinghua University)

The mesoscopic failure mechanism and the macro-mechanical characteristics of soil-rock mixture(S-RM) under external load are largely controlled by S-RM's meso-structural features. The objective of this work is to improve the three-dimensional technology for the generation of the random meso-structural models of S-RM, for randomly generating irregular rock blocks in S-RM with different shapes, sizes, and distributions according to the characteristics of the rock blocks' size distribution. Based on the new improved technology, a software system named as R-SRM3 D for generation and visualization of S-RM is developed. Using R-SRM3 D, a three-dimensional meso-structural model of S-RM is generated and used to study the meso-mechanical behavior through a series of true-triaxial numerical tests. From the numerical tests, the following conclusions are obtained. The meso-stress field of S-RM is influenced by the distribution of the internal rock blocks, and the macro-mechanical characteristics of S-RM are anisotropic in 3D; the intermediate principal stress and the soil-rock interface properties have significant influence on the macro strength of S-RM.

关键词： soil-rock mixture(S-RM) three dimensional meso-structure meso-structural mechanics(M-SM) true-triaxial numerical test random simulation

Biomedical rare-earth magnesium alloy:Current status and future prospects

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Journal of Magnesium and Alloys 2024年第4期12卷 1260-1282页

作者： Mingli Yang Cheng Chen Dongsheng Wang Yinjin Shao Wenhao Zhou Cijun Shuai Youwen Yang Xinghai Ning Institute of Additive Manufacturing Jiangxi University of Science and TechnologyNanchang 330013China Key Laboratory of Construction hydraulic Robots of Anhui Higher Education Institutes Tongling UniversityTongling 244061China department of Rehabilitation Ganzhou People’s HospitalGanzhou 341099China Shaanxi Key Laboratory of Biomedical Metallic Materials Northwest Institute for Non-Ferrous Metal ResearchXi’an 710016China State Key Laboratory of High Performance Complex Manufacturing Central South UniversityChangsha 410083China School of Mechanical and Electrical Engineering Jiangxi University of Science and TechnologyGanzhou 341000China College of Engineering and Applied Science Nanjing University210089China

Biomedical magnesium(Mg)alloys have garnered significant attention because of their unique biodegradability,favorable biocompatibility,and suitable mechanical *** incorporation of rare earth(RE)elements,with their distinct physical and chemical properties,has greatly contributed to enhancing the mechanical performance,degradation behavior,and biological performance of biomedical Mg ***,a series of RE-Mg alloys are being designed and investigated for orthopedic implants and cardiovascular stents,achieving substantial and encouraging research *** this work,a comprehensive summary of the state-of-the-art in biomedical RE-Mg alloys is *** physiological effects and design standards of RE elements in biomedical Mg alloys are ***,the degradation behavior and mechanical properties,including their underlying action are studied ***,the preparation techniques and current application status of RE-Mg alloys are ***,we address the ongoing challenges and propose future prospects to guide the development of high-performance biomedical Mg-RE alloys.

关键词： Magnesium alloy Rare earth elements Biodegradation behavior Mechanical performance Biological properties

Modelling hydrodynamic processes in tidal stream energy extraction

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Journal of Hydrodynamics 2016年第6期28卷 1058-1064页

作者：林杰林斌良孙健陈娅玲 department of hydraulic Engineering Tsinghua University

Tidal stream energy is a type of marine renewable energy which is close to commercial-scale production. Tidal stream turbine arrays are considered as the one of the most promising exploitation methods. However, compared to the relatively mature technology of single turbine design and installation, the current knowledge on the hydrodynamic processes of tidal stream turbine arrays is still limited. Coastal models with simplified turbine representations based on the shallow water equation are among the most favorable methods for studying the tidal stream energy extraction processes in realistic sites. This paper presents a review of the progress and challenges in assessing the tidal stream energy.

关键词： tidal stream energy coastal flow field shallow water equations turbine parameterization