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Numerical investigation of hydro-morphodynamic characteristics of a cascading failure of landslide dams

Journal of Mountain Science 2024年第6期21卷 1868-1885页

作者： zhong Qiming CHEN Lingchun mei Shengyao shan Yibo WU Hao ZHAO Kunpeng Department of Geotechnical Engineering Nanjing Hydraulic Research InstituteNanjing 210024China National Key Laboratory of Water Disaster Prevention Nanjing 210098China Key Laboratory of Reservoir and Dam Safety of the Ministry of Water Resources Nanjing 210029China

A cascading failure of landslide dams caused by strong earthquakes or torrential rains in mountainous river valleys can pose great threats to people’s lives,properties,and infrastructures.In this study,based on the three-dimensional Reynoldsaveraged Navier-Stokes equations(RANS),the renormalization group(RNG)k-εturbulence model,suspended and bed load transport equations,and the instability discriminant formula of dam breach side slope,and the explicit finite volume method(FVM),a detailed numerical simulation model for calculating the hydro-morphodynamic characteristics of cascading dam breach process has been developed.The developed numerical model can simulate the breach hydrograph and the dam breach morphology evolution during the cascading failure process of landslide dams.A model test of the breaches of two cascading landslide dams has been used as the validation case.The comparison of the calculated and measured results indicates that the breach hydrograph and the breach morphology evolution process of the upstream and downstream dams are generally consistent with each other,and the relative errors of the key breaching parameters,i.e.,the peak breach flow and the time to peak of each dam,are less than±5%.Further,the comparison of the breach hydrographs of the upstream and downstream dams shows that there is an amplification effect of the breach flood on the cascading landslide dam failures.Three key parameters,i.e.,the distance between the upstream and the downstream dams,the river channel slope,and the downstream dam height,have been used to study the flood amplification effect.The parameter sensitivity analyses show that the peak breach flow at the downstream dam decreases with increasing distance between the upstream and the downstream dams,and the downstream dam height.Further,the peak breach flow at the downstream dam first increases and then decreases with steepening of the river channel slope.When the flood caused by the upstream dam failure flows to the downstream dam,it can produce a surge wave that

关键词： Cascading landslide dams Cascading dam failure process Detailed numerical simulation model Flood amplification effect Parameter sensitivity analyses

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Enhanced visible light absorption of Bi2WO6/SiO2 with abundant adsorbed oxygen for the degradation of organic pollutant

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Particuology 2024年第5期88卷 210-217页

作者： Yuanting Wu Xiaoying Wang Wenlong zhong shan Zhang School of Material Science and Engineering Shaanxi University of Science and TechnologyXi'an 710021China

Heterogeneous photocatalysts exhibit high catalytic efficiency in the degradation of pollutants,but their stability and repeatability is not very good and requires high structural matching.Simply by nanosizing the pure Bi 2 WO6(BWO)photocatalyst without constructing a heterojunction,there is a significant improvement in its performance,with an enhancement effect of about 2.3 times(99.43%).The high photocatalytic degradation efficiency of the material can be attributed to the enhanced light absorption effect brought by the three-dimensional inverse-opal structure SiO 2(IS)and the abundant surface adsorbed oxygen generated after the formation of Si–O–W bonds.In addition,the introduction of IS greatly increases the surface area of nanostructured BWO,which accelerates the charge transfer process,while the adsorbed oxygen promotes the participation of·O2−in the photocatalytic reaction,thereby accelerating the consumption of photo-generated electrons and ultimately improving the separation of charge carriers.Furthermore,the matched photonic bandgap further improves the absorption and utilization of light of the material.In this work,we constructs Si–O–W bonds to obtain inverse-opal SiO2/Bi2 WO6 with uniformly growth of pure phase nano BWO,which provides a feasible strategy for the preparation of high-performance pure-phase photocatalysts.

关键词： Bi2WO6 SiO2 inverse-opal structure Photocatalysis Adsorbed oxygen

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Interfacial reaction between AZ91D magnesium alloy melt and mild steel under high temperature

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China Foundry 2024年第2期21卷 159-167页

作者： Jia-hong Dai Jian-yue Zhang Bin Jiang Xiang-jun Xu zhong-tao Jiang Hong-mei Xie Qing-shan Yang Guo-qing Zhang College of Materials Science and Engineering Yangtze Normal UniversityChongqing 408100China National Engineering Research Center for Magnesium Alloys College of Materials Science and EngineeringChongqing UniversityChongqing 400044China Chongqing Jiulongyuan High-tech Industry Group Co. Ltd.Chongqing 400080China Loncin Industry Co. Ltd.Chongqing 400080China Department of Materials Science and Engineering The Ohio State UniversityColumbusOH 43210USA Chongqing Key Laboratory of Materials Surface&Interface Science Chongqing University of Arts and SciencesChongqing 402160China School of Metallurgy and Material Engineering Chongqing University of Science and TechnologyChongqing 401331China

The metallurgical quality control of magnesium(Mg)and Mg alloys in melting process is required to ensure a satisfied mechanical and corrosion performance,while the typical used steel crucible introduces impurities and interfacial interaction during melting process.Therefore,a systematic study about impurities diffusion and interfacial interaction between molten Mg and steel is necessary.In the present study,the interfacial reaction between molten AZ91D Mg alloy and mild steel during melting process was investigated with the melting temperatures of 700℃,750℃ and 800℃.The results show that Al(Fe,Mn)intermetallic layer is the intermetallic primarily formed at the interfaces of AZ91D melt and mild steel.Meanwhile,Al_(8)(Mn,Fe)5is indexed between Al(Fe,Mn)and AZ91D.AlFe_(3)C appears between the mild steel and Al(Fe,Mn)at 700℃ and 750℃,but absent at 800℃ due to the increased solubility of carbon in Mg matrix.It is found that the growth of the intermetallic layer is controlled by diffusion mechanism,and Al and Mn are the dominant diffusing species in the whole interfacial reaction process.By measuring the thickness of different layers,the growth constant was calculated.It increases from 1.89(±0.03)×10^(-12)m^(2)·s^(-1)at 700℃ to 3.05(±0.05)×10^(-12)m^(2)·s^(-1)at 750℃,and 5.18(±0.05)×10^(-12)m^(2)·s^(-1)at 800℃.Meanwhile,the content of Fe is linearly increased in AZ91D with the increase of holding time at 700℃ and 750℃,while it shows a significantly increment after holding for 8 h at 800℃,indicating holding temperature is more crucial to determine the Fe content of AZ91D than holding time.

关键词： AZ91D mild steel interface reaction intermetallic growth kinetics

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Uncertainty and disturbance estimator-based model predictive control for wet flue gas desulphurization system

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Chinese Journal of Chemical Engineering 2024年第3期67卷 182-194页

作者： shan Liu Wenqi zhong Li Sun Xi Chen Rafal Madonski School of Energy and Environment Key Laboratory of Energy Thermal Conversion and Control of Ministry of EducationSoutheast UniversityNanjing 210096China Faculty of Automatic Control Electronics and Computer ScienceSilesian University of TechnologyGliwise 44-100Poland

Wet flue gas desulphurization technology is widely used in the industrial process for its capability of efficient pollution removal.The desulphurization control system,however,is subjected to complex reaction mechanisms and severe disturbances,which make for it difficult to achieve certain practically relevant control goals including emission and economic performances as well as system robustness.To address these challenges,a new robust control scheme based on uncertainty and disturbance estimator(UDE)and model predictive control(MPC)is proposed in this paper.The UDE is used to estimate and dynamically compensate acting disturbances,whereas MPC is deployed for optimal feedback regulation of the resultant dynamics.By viewing the system nonlinearities and unknown dynamics as disturbances,the proposed control framework allows to locally treat the considered nonlinear plant as a linear one.The obtained simulation results confirm that the utilization of UDE makes the tracking error negligibly small,even in the presence of unmodeled dynamics.In the conducted comparison study,the introduced control scheme outperforms both the standard MPC and PID(proportional-integral-derivative)control strategies in terms of transient performance and robustness.Furthermore,the results reveal that a lowpass-filter time constant has a significant effect on the robustness and the convergence range of the tracking error.

关键词： Desulphurization system Disturbance rejection Model predictive control Uncertainty and disturbance estimator Nonlinear system

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Cage-confinement synthesis of MoC nanoclusers as efficient sulfiphilic and lithiophilic regulator for superior Li–S batteries

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Rare Metals 2024年第2期43卷 624-634页

作者： Xing-Yuan Zhang mei-Na Lei shan Tian Jian-Gan Wang State Key Laboratory of Solidification Processing Center for Nano Energy MaterialsSchool of Materials Science and EngineeringNorthwestern Polytechnical University and Shaanxi Joint Laboratory of Graphene(NPU)Xi’an710072China

High-energy-density Li-S batteries are subjected to serious sulfur deactivation and short cycle lifetime caused by undesirable polysulfide shuttle effect and frantic lithium dendrite formation.In this work,a controllable cage-confinement strategy to fabricate molybdenum carbide(MoC)nanoclusters as a high-efficient sulfiphilic and lithiophilic regulator to mitigate the formidable issues of Li-S batteries is demonstrated.The sub-2 nm MoC nanoclusters not only guarantee robust chemisorption and fast electrocatalytic conversion of polysulfides to enhance the sulfur electrochemistry,but also homogenize Li^(+) flux to suppress the lithium dendrite growth.As a consequence,the MoC-modified separator endows the batteries with boosted reaction kinetics,promoted sulfur utilization,and improved cycling stability.A reversible capacity of 701 mAh·g^(−1) at a high rate of 5.0C and a small decay rate of 0.076%per cycle at 1.0C over 600 cycles are achieved.This study offers a rational route for design and synthesis of bifunctional nanoclusers with both sulfiphilicity and lithiophilicity for high-performance Li-S batteries.

关键词： Li-S batteries Nanocluster Electrocatalyst Polysulfide shuttle Li dendrites

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Effectivity and safety of trifocal intraocular lenses and capsular tension rings implantation for cataract patients with axial high myopia

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International Journal of Ophthalmology(English edition) 2024年第3期17卷 499-508页

作者： shan Hua Qiu-Xia Xie Hu Wang Jing-Xiang zhong Dongguan Aier Eye Hospital Jinan UniversityDongguan 523106Guangdong ProvinceChina Department of Ophthalmology the First Affiliated Hospital of Jinan UniversityGuangzhou 510630Guangdong ProvinceChina Department of Ophthalmology the Sixth Affiliated Hospital of Jinan UniversityDongguan 523576Guangdong ProvinceChina

●AIM:To assess effectivity and safety of trifocal intraocular lenses(IOLs)and capsular tension rings in treating cataract patients with axial high myopia.●METHODS:A prospective nonrandomized controlled clinical trial was conducted.Totally 98 eyes(74 patients)who underwent femtosecond laser-assisted cataract surgery(FLACS)with trifocal IOLs were enrolled in the study and followed up for 2y after surgery:46 eyes(33 patients)with capsular tension ring implantation in the long axial lengths(AL)group(260.05).The dysfunctional lens index and total modulation transfer function(MTF)average height were similar between the two groups.The postoperative internal coma aberrations in the axial high myopia eyes were significantly higher than that in the normal AL group(P<0.05).The total satisfaction score in the long AL group(91.32±2.76)was slightly higher than that in the normal AL group(90.36±3.47),but there was no difference(P=0.136).A statistically negative correlation was found between corrected distance visual acuity(CDVA)and dysfunctional lens index(r=-0.382,P=0.009),and between CDVA and the total MTF average height(r=-0.374,P=0.01).But there was no significant correlation between CDVA and total satisfaction score(r=0.059,P=0.696).Postoperative complications mainly presented as posterior capsular opacity(PCO),retinal detachment and cystoid macular edema.There was no difference in the incidence of fundus disease(6.5%vs 3.8%,P=0.663)or PCO(1

关键词： trifocal intraocular lenses capsular tension ring axial high myopia cataract visual quality

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Relationship Between Individuals’Epidemic Risk Perception Within Living Space and Subjective Well-Being:Empirical Evidence from China after the First Wave of COVID-19

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Chinese Geographical Science 2024年第2期34卷 369-382页

作者： SONG Jiangyu ZHOU Suhong KWAN mei-Po ZHENG zhong School of Geography and Planning Sun Yat-sen UniversityGuangzhou 510006China Guangdong Provincial Engineering Research Center for Public Security and Disaster Guangzhou 510275China Institute of Space and Earth Information Science the Chinese University of Hong KongHong Kong 999077China Department of Geography and Resource Management the Chinese University of Hong KongHong Kong 999077China Institute of Future Cities the Chinese University of Hong KongHong Kong 999077China Center for Territorial Spatial Planning and Real Estate Studies Beijing Normal UniversityZhuhai 519000China

It is common to observe the epidemic risk perception(ERP)and a decline in subjective well-being(SWB)in the context of public health events,such as Corona Virus Disease 2019(COVID-19).However,there have been few studies exploring the impact of individuals’ERP within living space on their SWB,especially from a geographical and daily activity perspective after the resumption of work and other activities following a wave of the pandemic.In this paper,we conducted a study with 789 participants in urban China,measuring their ERP within living space and examining its influence on their SWB using path analysis.The results indicated that individuals’ERP within their living space had a significant negative effect on their SWB.The density of certain types of facilities within their living space,such as bus stops,subway stations,restaurants,fast food shops,convenience shops,hospitals,and public toilets,had a significantly negative impact on their SWB,mediated by their ERP within living space.Additionally,participation in out-of-home work and other activities not only increased individuals’ERP within living space,but also strengthened its negative effect on their SWB.

关键词： subjective well-being epidemic risk perception living space the density of facilities out-of-home activities

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Effect of Hyperconjugation on Photovoltaic Performance in Pseduo-2D Perylene Diimide Derivatives

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Chinese Journal of Chemistry 2024年第7期42卷 725-730页

作者： Zhilong He Yuwen Hong Guangyu Li Tong shan Yi Zhang Hongliang zhong Schoolof Chemistry and Chemical Engineering Shanghai Key Lab of Electrical Insulation and Thermal AgingShanghai Jiao Tong UniversityShanghai200230China shanghai Institute of Organic Chemistry Chinese Academy of SciencesShanghai 200032China Shenzhen Research institute Shanghai Jiao Tong UniversityShenzhenGuangdong 518057China

Theπ-πinteraction is acknowledged as the predominant factor to determine the molecular packing in organic photovoltaic materials,while other non-covalent intermolecular interactions especially theσ-πhyperconjugation are often ignored.Herein,a perylene diimide(PDI)derivative named FIDT-PDI is designed and synthesized to shed light into the effect of hyperconjugation on the molecular packing and further the photovoltaic performance.Dynamic NMR and 2D NOE NMR demonstrate the formation of intermolecularσ-πhyperconjugation between the C—H bond of the PDI moiety in one molecule and the phenyl sidechain in another molecule of FIDT-PDI.Benefiting from theσ-πhyperconjugation,FIDT-PDI with twisted backbone reversely exhibits more ordered packing and stronger crystallinity compared with another PDI derivative FIDTT-PDI which has better planarity,consequently achieving superior PCE and higher carrier mobility.This contribution is the first paradigm to unravel the structure-property relationship betweenσ-πhyper-conjugation of conjugated materials and corresponding photovoltaic performance.

关键词： Hyperconjugation Weak intermolecular interactions Conformation Organic solar cells Nonfullerene acceptor Perylene diimide

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Outcomes of endoscopic sclerotherapy for jejunal varices at the site of choledochojejunostomy (with video): Three case reports

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World Journal of Gastroenterology 2024年第14期30卷 2059-2067页

作者： Jun Liu Peng Wang Li-mei Wang Jing Guo Ning zhong Department of Gastroenterology Qilu Hospital of Shandong UniversityJinan 250012Shandong ProvinceChina

BACKGROUND Hemorrhage associated with varices at the site of choledochojejunostomy is an unusual,difficult to treat,and often fatal manifestation of portal hypertension.So far,no treatment guidelines have been established.CASE SUMMARY We reported three patients with jejunal varices at the site of choledochojejun-ostomy managed by endoscopic sclerotherapy with lauromacrogol/α-butyl cyanoacrylate injection at our institution between June 2021 and August 2023.We reviewed all patient records,clinical presentation,endoscopic findings and treatment,outcomes and follow-up.Three patients who underwent pancre-aticoduodenectomy with a Whipple anastomosis were examined using conven-tional upper gastrointestinal endoscopy for suspected hemorrhage from the afferent jejunal loop.Varices with stigmata of recent hemorrhage or active he-morrhage were observed around the choledochojejunostomy site in all three patients.Endoscopic injection of lauromacrogol/α-butyl cyanoacrylate was carried out at jejunal varices for all three patients.The bleeding ceased and patency was observed for 26 and 2 months in two patients.In one patient with multiorgan failure and internal environment disturbance,rebleeding occurred 1 month after endoscopic sclerotherapy,and despite a second endoscopic sclero-therapy,repeated episodes of bleeding and multiorgan failure resulted in eventual death.CONCLUSION We conclude that endoscopic sclerotherapy with lauromacrogol/α-butyl cyanoac-rylate injection can be an easy,effective,safe and low-cost treatment option for jejunal varicose bleeding at the site of choledochojejunostomy.

关键词： Endoscopic sclerotherapy Jejunal varices Choledochojejunostomy Portal vein hypertension Case report

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Nano polystyrene microplastics could accumulate in Nile tilapia(Oreochromis niloticus):Negatively impacts on the intestinal and liver health through water exposure

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Journal of Environmental Sciences 2024年第3期137卷 604-614页

作者： Di Wu Xing Lu Li-Xue Dong Juan Tian Jin Deng Lei Wei Hua Wen shan zhong Ming Jiang School of Basic Medical Sciences Wuhan UniversityWuhan 430071China Key Laboratory of Freshwater Biodiversity Conservation Ministry of Agriculture and Rural AffairsYangtze River Fisheries Research InstituteChinese Academy of Fishery SciencesWuhan 430223China Hubei Province Key Laboratory of Allergy and Immunology Wuhan 430071China

Microplastics(MPs)have become a significant concern for their potential toxicity.However,the correlation between the size of plastic particles and their toxicity remains inconclusive.Here,we investigate the toxic effects of different sizes(80 nm,800 nm,8μm and 80μm)polystyrene MPs(PS-MPs)on the model organism Nile tilapia(Oreochromis niloticus).The results of bioluminescent imaging indicate that the 80 nm PS-MPs are more likely to invade the body.H&E staining shows severe damage on the intestinal villi and distinct hepatic steatosis in the 80 nm group.Ed U labeling shows that the proliferation activity of intestinal and liver cells reduces significantly in the 80 nm group.The gut microbiome analysis shows a severe imbalance of gut microbiota homeostasis in the 80 nm group.The analysis of liver transcriptomics and metabolomics shows that the liver lipid metabolism is disordered in the 80 nm group.In conclusion,this study confirms that the 80 nm PS-MPs are more likely to induce intestinal and liver toxicity.All the above lay the foundation for further study on the pathological damage of MPs to other organisms.

关键词： Microplastics(MPs) Intestinal toxicity Liver toxicity Gut microbiome Lipid metabolism

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