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Acta Mechanica Sinica 2011年第3期27卷 339-345页

作者： Jin-ling Luo hong-lin kang Jian Li Wu-Ye Dai Northwestern Polytechnical University 710072 Xi'an China Beijing Electro-Mechanical Engineering Institute100074 Beijing China

Numerical simulation methods of aerodynamic heating were compared by considering the inuence of numerical schemes and turbulence models,and attempting to investigate the applicability of numerical simulation methods on predicting heat flux in engineering applications. For some typical cases provided with detailed experimental data,four spatial schemes and four turbulence models were adopted to calculate surface heat flux. By analyzing and comparing,some inuencing regularities of numerical schemes and turbulence models on calculating heat flux had been acquired. It is clear that AUSM＋-up scheme with rapid compressibilitymodified high Reynolds number k鈥撓？model should be appropriate for calculating heat flux. The numerical methods selected as preference above were applied to calculate the heat flux of a 3-D complex geometry in high speed turbulent flows. The results indicated that numerical simulation can capture the complex flow phenomena and reveal the mechanism of aerodynamic heating. Especially,the numerical result of the heat flux at the stagnation point of the wedge was well in agreement with the prediction of Kemp鈥揜iddel formula,and the surface heat flux distribution was consistent with experiment results,which implied that numerical simulation can be introduced to predict heat flux in engineering applications.

关键词： Aerodynamic heating . Complex configurations . Numerical simulation

Establishment of a chicken intestinal organoid culture system to assess deoxynivalenol‑induced damage of the intestinal barrier function

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Journal of Animal Science and Biotechnology 2024年第3期15卷 1119-1130页

作者： Tae hong kang Sang In Lee Department of Animal Science and Biotechnology Kyungpook National UniversitySangjuGyeong‑Sangbuk‑Do 37224Republic of Korea Research Institute for Innovative Animal Science Kyungpook National University37224SangjuGyeong‑Sangbuk‑DoRepublic of Korea

Background Deoxynivalenol(DON)is a mycotoxin that has received recognition worldwide because of its ability to cause growth delay,nutrient malabsorption,weight loss,emesis,and a reduction of feed intake in *** DON-contaminated feedstuff is absorbed in the gastrointestinal tract,we used chicken organoids to assess the DON-induced dysfunction of the small *** We established a culture system using chicken organoids and characterized the organoids at passages 1 and *** confirmed the mRNA expression levels of various cell markers in the organoids,such as KI67,leucine-rich repeat containing G protein-coupled receptor 5(Lgr5),mucin 2(MUC2),chromogranin A(CHGA),cytokeratin 19(CK19),lysozyme(LYZ),and microtubule-associated doublecortin-like kinase 1(DCLK1),and compared the results to those of the small *** results showed that the organoids displayed functional similarities in permeability compared to the small *** damaged the tight junctions of the organoids,which resulted in increased *** Our organoid culture displayed topological,genetic,and functional similarities with the small intes-tine *** on these similarities,we confirmed that DON causes small intestine *** organoids offer a practical model for the research of harmful substances.

关键词： Barrier function Deoxynivalenol Organoids

Steel-refractory reactions in lanthanum-,cerium-,and ytrium-added steels

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Journal of Iron and Steel Research International 2024年第6期31卷 1473-1485页

作者： Jian kang hong-po Wang Yu Wang College of Materials Science and Engineering Chongqing UniversityChongqing 400044China The State Key Laboratory of Mechanical Transmissions Chongqing UniversityChongqing 400044China

A systematic experimental study was conducted on the similarities and differences in the reactions between commonly used rare earth elements(REEs)and frequently used refractories in the steelmaking *** results indicate that the reaction behaviors of La,Ce,and Y with MgO,Al_(2)O_(3),and MgO·Al_(2)O_(3) crucibles differed *** consumption rates of La,Ce,and Y in the molten steel were in descending order of La>Ce>Y for smelting with all three kinds of *** the REEs reacted with the crucible,the contents of Mg and Al showed a trend of first increasing and then *** laboratory-scale smelting conditions,the reactions related to REEs were dominated by steel-crucible reactions,and the contact area between the unit mass of molten steel and refractory materials mainly determined the consumption rates of ***-and Ce-crucible reactions generated loose and porous reaction interfaces;however,Y-crucible reactions generated a dense Y_(2)O_(3) layer,dramatically suppressing the consumption rate of *** calculation indicated that the reactions between rare earth and different refractory materials were first-order *** crucible materials significantly affected the product type and morphology of the steel-crucible reaction interfaces,thereby influencing the consumption rate of *** reactions between REEs and refractories must be seriously considered,especially for small-scale smelting.

关键词： Rare earth Inclusion Refractory Thermodynamics Dynamics

Evaluation of internal void related defects in reinforced concrete slab using electromagnetic wave properties

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Earthquake Engineering and Engineering Vibration 2024年第3期23卷 525-535页

作者： Minju kang Jinyoung hong Taemin Lee Doyun Kim Hajin Choi School of Architecture Soongsil UniversitySeoul 06978Republic of Korea

This study aims to develop a damage-detection algorithm based on the electromagnetic wave properties inside a reinforced concrete *** proposed method involves employing two algorithms based on data measured using ground-penetrating radar—a common electromagnetic wave method in civil *** possible defect area was identified based on the energy dissipated by the damage in the frequency-wavenumber domain,with the damage localized using the calculated relative permittivity of the *** proposed method was verified through a finite difference time-domain-based numerical analysis and a testing slab with artificial *** a result of verification,the proposed method quickly identified the presence of damage inside the concrete,especially for honeycomb-like defects located at the top of the *** study has practical significance in scanning structures over a large area more quickly than other non-destructive testing methods,such as ultrasonic methods.

关键词： GPR concrete defect electromagnetic wave relative permittivity non-destructive testing(NDT)

Core shift limitation in investment casting process of hollow turbine blade

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Chinese Journal of Aeronautics 2024年第8期37卷 513-526页

作者： kang CUI lin JING Ruisong JIANG Longnv YU Xiao GAO Automation and Software Engineering Shanxi UniversityTaiyuan 030006China Key Laboratory of High Performance Manufacturing for Aero Engine Ministry of Industry and Information TechnologySchool of Mechanical EngineeringNorthwestern Polytechnical UniversityXi’an 710072China School of Mechanical Engineering Sichuan UniversityChengdu 610065China

The deviation in wall thickness caused by core shift during the investment casting process significantly impacts the strength and service life of hollow turbine *** address this issue,a core shift limitation method is developed in this ***,a shift model is established based on computational fluid dynamics and motion simulation to predict the movement of the ceramic core in investment casting ***,utilizing this model,an optimization method for fixturing layout inside the refractory ceramic shell is devised for the ceramic *** casting experiment demonstrates that by utilizing the optimized fixture layout,not only can core shift during the investment casting pouring process be effectively controlled,but also the maximum wall thickness error of the blade can be reduced by 42.02%.In addition,the core shift prediction is also validated,with a prediction error of less than 26.9%.

关键词： Hollow turbine blade Wall thickness Ceramic core Shift prediction Fixturing layout optimization

Heterobimetallic[NiCo]integration in a hydrogenase mimic for boosting light-driven hydrogen evolution in CaTiO_(3)

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Nano Research 2024年第8期17卷 6888-6894页

作者： kang Li Juanji hong Ningning Song Zhanjun Guo Minmin Liang Experimental Center of Advanced Materials School of Materials Science&EngineeringBeijing Institute of TechnologyBeijing 10081China

Light-drive hydrogen production using titanium-based perovskite is one sustainable way to reduce current reliance on fossil fuels,but its wide applications are still limited by high electron−hole recombination and sluggish surface ***,the developments for low-cost and highly efficient co-catalysts remain *** by natural[NiFe]-hydrogenase active center structure,a hydrogenase-mimic,NiCo_(2)S_(4) nanozyme was synthesized,and subsequently decorated onto the CaTiO_(3) to catalyze the hydrogen evolution reaction(HER).Among the following test,CaTiO_(3)with a 15%loading of NiCo_(2)S_(4) nanozyme exhibited the highest HER rate of 307.76μmol·g^(–1)·h^(–1),which is 60 times higher than that of the CaTiO_(3) *** results reveal that NiCo_(2)S_(4) not only significantly increased the charge separation efficiency of the photogenerated carriers,but also substantively lowered the HER activation *** studies show that NiCo_(2)S_(4) readily splits H_(2)O by forming the Ni(OH)-Co intermediate and only Ni in the bimetallic center alters the oxidation state during the HER process in a manner analogous to the[NiFe]-*** contrast to the often-expensive synthetic catalysts that rely on rare elements such as ruthenium and platinum,this study shows a promising way to develop the nature-inspired cocatalysts to enhance the photocatalysts’HER performance.

关键词： hydrogen evolution reaction hydrogenase-mimic nanozyme photocatalyst water-splitting

Biotic and abiotic stresses on honeybee health

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Integrative Zoology 2024年第3期19卷 442-457页

作者： Zheguang lin Siyi SHEN kang WANG Ting JI Apicultural Research Institute College of Animal Science and TechnologyYangzhou UniversityYangzhouChina

Honeybees are the most critical pollinators providing key ecosystem services that underpin crop production and sustainable *** a backdrop of rapid global change,this eusocial insect encounters a succession of stressors during nesting,foraging,and *** mites,together with vectored viruses,have been recognized as central biotic threats to honeybee health,while the spread of invasive giant hornets and small hive beetles also increasingly threatens colonies *** of agrochemicals,including acaricides used for mite treatment,and other pollutants of the environment have been widely documented to affect bee health in various ***,expanding urbanization,climate change,and agricultural intensification often result in the destruction or fragmentation of flower-rich bee *** anthropogenic pressures exerted by beekeeping management practices affect the natural selection and evolution of honeybees,and colony translocations facilitate alien species invasion and disease *** this review,the multiple biotic and abiotic threats and their interactions that potentially undermine bee colony health are discussed,while taking into consideration the sensitivity,large foraging area,dense network among related nestmates,and social behaviors of honeybees.

关键词： abiotic stressor Apis biotic stressor colony losses interaction effect pollinator decline

Light-triggered fluorochromic cholesteric liquid crystal elastomer with hydrogen-bonded fluorescent switch: dualmodal-switchable circularly polarized luminescence

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Science China Chemistry 2024年第8期67卷 2719-2727页

作者： Siyang lin Tianqi Ren Xianyu Meng Wenxin kang Jinbao Guo Key Laboratory of Carbon Fibers and Functional Polymers Ministry of EducationCollege of Materials Science and EngineeringBeijing University of Chemical TechnologyBeijing 100029China

Solid materials with dynamically tunable circularly polarized luminescence(CPL) feature higher security levels and devicefriendly characteristics, showing great superiority in the field of information technology and anti-counterfeiting. To address the limited photoisomerization of fluorescent photoswitch in CPL-active solid materials, here a cholesteric liquid crystal elastomer(CLCE) containing a hydrogen-bonded(H-bonded) polymerizable fluorescent switch AHBA-PSD is prepared. Owing to the good flexibility and low glass-transition temperature of CLCE, AHBA-PSD shows a fast and fully reversible photocyclization/cycloreversion with fluorochromic behavior in CLCE. Further, by controlling the spectral overlapping area between the emission and reflection bands, the CLCE exhibits a strong CPL with a g_(lum) value of up to 0.76 accompanied by a reversible phototunable CPL signal. Meanwhile, the H-bond helps to stabilize the mechanical property, and the force-induced switching-off of CPL signal could be achieved due to the destroyed helical structures by external force. Finally, an automatically-recognized identification card with abundant chiroptical information is demonstrated.

关键词： cholesteric liquid crystal elastomer circularly polarized luminescence fluorescent photoswitch diarylethene photoismerization

Local Hybrid linear State Estimation for Electric Power Systems Using Stream Processing

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CSEE Journal of Power and Energy Systems 2024年第3期10卷 1259-1268页

作者： kang Sun Manyun Huang Zhinong Wei Yuzhang lin Guoqiang Sun College of Energy and Electrical Engineering Hohai UniversityNanjing 210098China Department of Department of Electrical and Computer Engineering University of Massachusetts LowellLowell MA 01854USA IEEE

The increasing penetration of renewable energy resources with highly fluctuating outputs has placed increasing concern on the accuracy and timeliness of electric power system state estimation(SE).Meanwhile,we note that only a fraction of system states fluctuate at the millisecond level and require to be *** such,refreshing only those states with significant variation would enhance the computational efficiency of SE and make fast-continuous update of states ***,this is difficult to achieve with conventional SE methods,which generally refresh states of the entire system every 4–5 *** this context,we propose a local hybrid linear SE framework using stream processing,in which synchronized measurements received from phasor measurement units(PMUs),and trigger/timingmode measurements received from remote terminal units(RTUs)are used to update the associated local ***,the measurement update process efficiency and timeliness are enhanced by proposing a trigger measurement-based fast dynamic partitioning algorithm for determining the areas of the system with states requiring *** particular,non-iterative hybrid linear formulations with both RTUs and PMUs are employed to solve the local SE *** timeliness,accuracy,and computational efficiency of the proposed method are demonstrated by extensive simulations based on IEEE 118-,300-,and 2383-bus systems.

关键词： Fast dynamic partitioning local hybrid linear state estimation phasor measurement units stream processing timeliness trigger/timing-mode measurements

Intelligent responsive self-assembled micro-nanocapsules: Used to delay gel gelation time

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Petroleum Science 2024年第4期21卷 2433-2443页

作者： Chuan-hong kang Ji-Xiang Guo Dong-Tao Fei Wyclif Kiyingi Unconventional Petroleum Research Institute China University of Petroleum

In the application of polymer gels to profile control and water shutoff,the gelation time will directly determine whether the gel can "go further" in the formation,but the most of the methods for delaying gel gelation time are complicated or have low *** is an urgent need for an effective method for delaying gel gelation time with intelligent *** by the slow-release effect of drug capsules,this paper uses the self-assembly effect of gas-phase hydrophobic SiO2in aqueous solution as a capsule to prepare an intelligent responsive self-assembled *** capsule slowly releases the cross-linking agent under the stimulation of external conditions such as temperature and pH value,thus delaying gel gelation *** the pH value is 2 and the concentration of gas-phase hydrophobic SiO2particles is 10%,the gelation time of the capsule gel system at 30,60,90,and 120℃ is12.5,13.2,15.2,and 21.1 times longer than that of the gel system without containing capsule,*** with other methods,the yield stress of the gel without containing capsules was 78 Pa,and the yield stress after the addition of capsules was 322 *** intelligent responsive self-assembled micronanocapsules prepared by gas-phase hydrophobic silica nanoparticles can not only delay the gel gelation time,but also increase the gel *** slow release of cross-linking agent from capsule provides an effective method for prolongating the gelation time of polymer gels.

关键词： Profile control and water shutoff Polymer gel Delayed gelation time Intelligent response Self-assembled Micro-nanocapsules