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Numerical simulation analysis of wind field above pavement surface in different landforms by computational fluid dynamics approach

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Journal of Traffic and Transportation Engineering(English Edition) 2024年第3期11卷 559-573页

作者： Jian Ouyang zhao Jiang Leiyu Ye jing Li Peng Cao School of Civil Engineering and Architecture Hainan UniversityHaikou 570000China School of Transportation and Logistics Dalian University of TechnologyDalian 116024China Hexagon Manufacturing Intelligence(qingdao)Co. Ltd.Qingdao 266000China China Tower Co. Ltd.Dalian BranchDalian 116024China Faculty of Architecture Civil and Transportation EngineeringBeijing University of TechnologyBeijing 100124China

The temperature and moisture of the pavement structure can be greatly influenced by the wind speed above pavement *** wind speed above pavement surface not only is dominated by the wind speed of atmosphere,but also it is highly related to the landform and buildings around ***,currently there are no studies about the wind field above pavement surface in consideration of the effect of the landform and buildings.A simulation method,which is combined with geographic information system(GIS),wind data from meteorological observatory and computational fluid dynamics(CFD)software,is employed to study the effect of the landform and the wind speed of atmosphere on the wind field above pavement *** cases are studied,including an urban road,a coastal road and a mountainous ***,the wind field distribution above road surface in different wind directions was studied in our *** indicate that the wind field above pavement surface can be greatly affected by the landforms,buildings and wind *** simulation method can provide reliable results for the wind field above pavement *** maximum relative errors between simulated and measured wind speed can be less than 20%in the analysis of the three *** is recommended that the CFD simulation method is a good tool to accurately know the wind field above pavement surface.

关键词： Wind field above pavement surface Computational fluid dynamics Landforms Geographic information system Simulation

The environment,especially the minimum temperature,affects summer maize grain yield by regulating ear differentiation and grain development

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Journal of Integrative Agriculture 2024年第7期23卷 2227-2241页

作者： jing Chen Baizhao Ren Bin zhao Peng Liu Jiwang Zhang State Key Laboratory of Crop Biology/College of Agronomy Shandong Agricultural UniversityTai’an 271018

Ear differentiation,grain development and their interaction with factors in the growing environment,such as temperature,solar radiation and precipitation,greatly influence grain number and grain weight,and ultimately affect summer maize *** this study,field experiments involving different sowing dates were conducted over three years to evaluate the effects of temperature factors,average solar radiation and total precipitation on the growth process,ear differentiation,fertilization characteristics,grain filling and yield of summer maize varieties with different growth *** hybrids were evaluated in Huang-Huai-Hai Plain(HHHP),China from 2018 to 2020 with five different sowing *** results showed that the grain yield formation of summer maize was strongly impacted by the environment from the silking(R1)to milking(R3)*** minimum temperature(AT_(min))was the key environmental factor that determined *** in the length of the growing season(r=–0.556,P<0.01)and the total floret number on ear(R^(2)=0.200,P<0.001)were found when AT_(min) was elevated from the emerging(VE)to R1 *** grain-filling rate(R^(2)=0.520,P<0.001)and the floret abortion rate on ear(R^(2)=0.437,P<0.001)showed quadratic relationships with AT_(min) from the R1 to physiological maturity(R6)stage,while the number of days after the R1 stage(r=–0.756,P<0.01)was negatively correlated with AT_(min).An increase in AT_(min) was beneficial for the promotion of yield when it did not exceeded a certain level(above 23°C during the R1–R3 stage and 20–21°C during the R1-R6 stage).Enhanced solar radiation and precipitation during R1–R6 increased the grain-filling rate(R^(2)=0.562,P<0.001 and R^(2)=0.229,P<0.05,respectively).Compared with short-season hybrids,full-season hybrids showed much greater suitability for a critical *** coordinated regulation of AT_(min),ear differentiation and grain development at the pre-and post-silking stages improved maize yie

关键词： sowing date hybrid maturity growing environment ear differentiation and grain development

A modified 3D mean strain energy density criterion for predicting shale mixed-mode Ⅰ/Ⅲ fracture toughness

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第7期16卷 2411-2428页

作者： Kun Zheng Chaolin Wang Yu zhao jing Bi Haifeng Liu College of Civil Engineering Guizhou UniversityGuiyang550025China State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China

The fracture toughness of rocks is a critical fracturing parameter in geo-energy exploitation playing a significant role in fracture mechanics and hydraulic *** edge-notched disk bending(ENDB)specimens are employed to measure the entire range of mixed-modeⅠ/Ⅲfracture toughness of Longmaxi *** theoretically interpret the fracture mechanisms,this research first introduces the detailed derivations of three established fracture *** distinguishing the volumetric and distortional strain energy densities,an improved three-dimensional mean strain energy density(MSED)criterion is *** the critical volumetric to distortional MSED ratio decreases,the transition from tensiondominated fracture to shear-dominated fracture is *** results indicate that both peak load and applied energy increase significantly with the transition from pure mode I(i.e.,tension)to pure modeⅢ(i.e.,torsion or tearing)since mode-Ⅲcracking happens in a twisted manner and mode-Ⅰcracking occurs in a coplanar *** macroscopic fracture signatures are consistent with those of triaxial hydraulic *** average ratio of pure mode-Ⅲfracture toughness to pure mode-Ⅰfracture toughness is 0.68,indicating that the obtained mode-Ⅲfracture resistance for a tensionbased loading system is apparent rather than *** to the three mainstream fracture criteria,the present fracture criterion exhibits greater competitiveness and can successfully evaluate and predict mixed-modeⅠ/Ⅲfracture toughness of distinct materials and loading methods.

关键词： Longmaxi shale Hydraulic fracturing Fracture mechanisms Fracture criteria Mixed-modeⅠ/Ⅲfracture toughness Edge-notched disk bending

Microencapsulated Lactobacillus plantarum promotes intestinal development through gut colonization of layer chicks

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Animal Nutrition 2024年第3期18卷 1-16页

作者： Yaoming Cui Yanxia Liu jing Yang Haitao Duan Peng Wang Linna Guo Yanjiao Guo Suying Li Yating zhao Jinrong Wang Guanghai qi Junjun Guan School of Biological Engineering Henan University of TechnologyZhengzhouHenan 450001China College of Animal Science and Technology Henan University of Animal Husbandry and EconomyZhengzhouHenan 450046China Feed Research Institute Chinese Academy of Agricultural SciencesBeijing 100081China

The effects of Lactobacillus plantarum in microencapsulation(LPM)on intestinal development in layer chicks were investigated in this study,as well as the colonization of *** in the gut.A total of 480 healthy Hy-Line Brown layer chicks at 0 d old were randomly divided into 4 groups(8 replicates each treatment),and the diets of these birds were supplemented with nothing(control),***(0.02 g/kg feed;109 CFU/kg feed),LPM(1.0 g/kg feed;109 CFU/kg feed)and wall material of LPM(WM;0.98 g/kg feed),*** to control,LPM improved growth performance and intestinal development of layer chicks,evidenced by significantly increased body weight,average daily gain,average daily feed intake,villus height,villus height/crypt depth,as well as weight and length of the duodenum,jejunum and ileum(P<0.05).These results could be attributed to the increased colonization of *** in the gut,which was verified by significant increases in lactic acid content,viable counts in chyme and mucosa(P<0.05),as well as a visible rise in number of strains labeled with fluorescein ***,the relative abundances of Lactobacillus and Bifidobacterium significantly increased in response to microencapsulated *** supplementation(P<0.05),accompanied by the significant up-regulation of colonization related genes(P<0.05),encoding solute carrier family,monocarboxylate transporter,activin A receptor,succinate receptor and secretogranin *** sum up,microencapsulated *** supplementation promoted intestinal development,which could be attributed to the enhancement of *** colonization in the intestine through the mutual assistance of Bifidobacterium and interactions with colonization related transmembrane proteins.

关键词： Intestinal development Colonization Microbiota Layer chick Lactobacillus plantarum

Targeted therapeutic effects of oral magnetically driven pectin nanoparticles containing chlorogenic acid on colon cancer

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Particuology 2024年第1期84卷 53-59页

作者： Huatai Zhu Limei Zhang Fujia Kou jingyang zhao Jiandu Lei jing He Beijing Key Laboratory of Lignocellulosic Chemistry Beijing Forestry UniversityBeijing100083China Institute of Biopharmaceutical and Health Engineering Tsinghua Shenzhen International Graduate SchoolTsinghua UniversityShenzhen518055China

Oral colonic nano-drug delivery system has attracted growing attention in treating colon cancer for their excellent ***,the unique and complex structure of the gastrointestinal tract is still an obstacle to the safe delivery of drugs targeting sites in colon ***,we designed magnetically driven dual-targeted oral colonic nanoparticles loaded with chlorogenic acid using pectin and oleic acid-modified iron oxide(Fe3O4@OA).Specific degradation of pectin by pectinase produced by colonic flora and magnetic fields applied to the colon confers specific targeting of nanoparticles to the *** order to overcome the challenge of preparing magnetically driven nanoparticles with small and homogeneous particle sizes by a single conventional method,we developed the combined ultrasound-emulsification *** average particle size of the prepared nanoparticles was 81.04±1.02 nm,which showed good drug release in the simulated colonic *** vitro anticancer studies,the drug-loaded nanoparticles possess an obvious toxicity and apoptosis-inducing ability against cancer ***,the hemolysis results demonstrated the safety of the nanoplatform(PET/CGA/Fe_(3)O_(4)@OA).This work holds broad prospects as a new treatment modality for colon cancer.

关键词： Pectin Chlorogenic acid Ultrasound-emulsion Magnetically driven Colon cancer Colon targeted

Improved forecasting via physics-guided machine learning as exemplified using“21·7”extreme rainfall event in Henan

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Science China Earth Sciences 2024年第5期67卷 1652-1674页

作者： qi ZHONG Zhicha ZHANG Xiuping YAO Shaoyu HOU Shenming FU Yong CAO Linguo jing China Meteorological Administration Training Center Beijing 100081China State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesBeijing 100081China Zhejiang Meteorological Observatory Hangzhou 310017China Hebei Provincial Weather Modification Center Shijiazhuang 050020China Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029China National Meteorological Center Beijing 100081China School of Computer Science Chengdu University of Information TechnologyChengdu 610225China

As a natural disaster,extreme precipitation is among the most destructive and influential,but predicting its occurrence and evolution accurately is very challenging because of its rarity and *** the example of the“21·7”extreme precipitation event(17–21 July 2021)in Henan Province,this study explores the potential of using physics-guided machine learning to improve the accuracy of forecasting the intensity and location of extreme *** physics-guided ways of embedding physical features,fusing physical model forecasts and revised loss function are used,i.e.,(1)analyzing the anomalous circulation and thermodynamical factors,(2)analyzing the multi-model forecast bias and the associated underlying reasons for it,and(3)using professional forecasting knowledge to design the loss function,and the corresponding results are used as input for machine learning to improve the forecasting *** results indicate that by learning the relationship between anomalous physical features and heavy precipitation,the forecasting of precipitation intensity is improved significantly,but the location is rarely adjusted and more false alarms *** reasons for this are as *** anomalous features used here mainly contain information about large-scale systems and factors which are consistent with the model precipitation deviation;moreover,the samples of extreme precipitation are sparse and so the algorithm used here is ***,by combining“good and different”multi models with machine learning,the advantages of each model are extracted and then the location of the precipitation center in the forecast is improved ***,by combining the appropriate anomalous features with multi-model fusion,an integrated improvement of the forecast of the rainfall intensity and location is ***,this study is a novel exploration to improve the refined forecasting of heavy precipitation with extreme intensity and high variability,

关键词： Extreme precipitation event Refined assessment Anomalous physical features Multi-model fusion Machine learning

Durable dual-state duplex Si-HfO_(2)with excellent oxidation and cracking resistance

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Journal of Advanced Ceramics 2024年第3期13卷 388-401页

作者： Lin Chen jing-Chuan Luo Wen-qi Yang Chang-Jiu Li Guan-Jun Yang State Key Laboratory for Mechanical Behavior of Materials School of Materials Science and EngineeringXi’an Jiaotong UniversityXi’an 710049China Xi’an Aerospace Engine Company Limited in CASC Xi’an 710065China

The lifetime of Si bond coatings in environmental barrier coatings is constrained by phase-transition-induced cracking of the SiO_(2)*** this study,Si-HfO_(2)dual-state duplex composite materials are proposed to address this issue by partially forming HfSiO_(4)and minimizing the SiO_(2)*** as-prepared composite exhibited a structure comprising discrete HfO_(2)“bricks”embedded in a continuous Si“mortar”,while the oxidized state transformed into discrete HfSiO_(4)“bricks”within continuous thin SiO_(2)“mortars”.The results indicate that continuous thin SiO_(2)contributes to reducing the oxidation rate to a level comparable to that of pure Si,and discrete HfSiO_(4)particles aid in relieving phase transition-induced stress and inhibiting crack propagation,thereby enhancing oxidation and cracking resistance ***,the composite with 20 mol%HfO_(2)and a mean particle size of~500 nm at 1370℃exhibited a service lifetime 10 times greater than that of pure *** research provides valuable insights for designing Si-based bond coatings with improved service lifetime.

关键词： oxidation environmental barrier coatings(EBCs) phase transition cracking bond coatings

Molecular engineering binuclear copper catalysts for selective CO_(2) reduction to C_(2) products

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Journal of Energy Chemistry 2024年第6期93卷 166-173,I0005页

作者： qi zhao Kai Lei Bao Yu Xia Rachel Crespo-Otero Devis Di Tommaso Department of Chemistry School of Physical and Chemical SciencesQueen Mary University of LondonLondonE14NSUK Key Laboratory of Material Chemistry for Energy Conversion and Storage(Ministry of Education) Hubei Key Laboratory of Material Chemistry and Service FailureState Key Laboratory of Materials Processing and Die&Mould TechnologySchool of Chemistry and Chemical EngineeringHuazhong University of Science and Technology(HUST)Wuhan 430074HubeiChina Department of Chemistry University College LondonLondonWC1H 0AJUK Digital Environment Research Institute Queen Mary University of LondonEmpire HouseLondon E11HHUK

Molecular copper catalysts serve as exemplary models for correlating the structure-reaction-mechanism relationship in the electrochemical CO_(2) reduction(eCO_(2)R),owing to their adaptable environments surrounding the copper metal *** investigation,employing density functional theory calculations,focuses on a novel family of binuclear Cu molecular *** modulation of their coordination configuration through the introduction of organic groups aims to assess their efficacy in converting CO_(2) to C_(2)*** findings highlight the crucial role of chemical valence state in shaping the characteristics of binuclear Cu catalysts,consequently influencing the eCO_(2)R behaviour,Notably,the Cu(Ⅱ)Cu(Ⅱ)macrocycle catalyst exhibits enhanced suppression of the hydrogen evolution reaction(HER),facilitating proton trans fer and the eCO_(2)R *** rthermore,we explo re the impact of diverse electro n-withdrawing and electron-donating groups coordinated to the macrocycle(R=-F,-H,and-OCH_3)on the electron distribution in the molecular *** placement of-OCH_3 groups in the macrocycles leads to a favourable oxidation state of the Cu centres and subsequent C-C coupling to form C_(2) *** research provides fundamental insights into the design and optimization of binuclear Cu molecular catalysts for the electrochemical conversion of CO_(2) to value-added C_(2) products.

关键词： Molecular catalyst design Selective CO_(2)reduction C_(2)products Density functional theory calculations

A Temporary Frequency Response Strategy Using a Voltage Source-Based PermanentMagnet Synchronous Generator and Energy Storage Systems

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Energy Engineering 2024年第2期121卷 541-555页

作者： Baogang Chen Fenglin Miao jing Yang Chen qi Wenyan Ji CSIC HaiZhuangWindpower Co. Ltd.Chongqing400000China State Key Laboratory of Operation and Control of Renewable Energy&Storage Systems China Electric Power Research InstituteBeijing100000China

Energy storage systems(ESS)and permanent magnet synchronous generators(PMSG)are speculated to be able to exhibit frequency regulation capabilities by adding differential and proportional control loops with different control *** available PMSG kinetic energy and charging/discharging capacities of the ESS were *** improve the inertia response and frequency control capability,we propose a short-term frequency support strategy for the ESS and *** this end,the weights were embedded in the control loops to adjust the participation of the differential and proportional controls based on the system frequency *** effectiveness of the proposed control strategy was verified using PSCAD/*** simulations revealed that the proposed strategy could improve the maximum rate of change of the frequency nadir and maximum frequency ***,it provides a promising solution of ancillary services for frequency regulation of PMSG and ESS.

关键词： Inertial control PMSG ESS wind power generation frequency support