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Stability analysis of a liquid crystal elastomer self-oscillator under a linear temperature field

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Applied Mathematics and Mechanics(English Edition) 2024年第2期45卷 337-354页

作者： Haiyang WU Jiangfeng LoU Biao ZHANG Yuntong dai Kai LI School of Civil Engineering Anhui Jianzhu UniversityHefei 230601China

Self-oscillating systems abound in the natural world and offer substantial potential for applications in controllers,micro-motors,medical equipments,and so ***,numerical methods have been widely utilized for obtaining the characteristics of self-oscillation including amplitude and ***,numerical methods are burdened by intricate computations and limited precision,hindering comprehensive investigations into self-oscillating *** this paper,the stability of a liquid crystal elastomer fiber self-oscillating system under a linear temperature field is studied,and analytical solutions for the amplitude and frequency are ***,we establish the governing equations of self-oscillation,elucidate two motion regimes,and reveal the underlying ***,we conduct a stability analysis and employ a multi-scale method to obtain the analytical solutions for the amplitude and *** results show agreement between the multi-scale and numerical *** research contributes to the examination of diverse self-oscillating systems and advances the theoretical analysis of self-oscillating systems rooted in active materials.

关键词： self-oscillation stability analysis multi-scale method liquid crystal elastomer linear temperature field

Effect of streamlined nose length on aerodynamic performance of high-speed train with a speed of 400 km/h

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第7期25卷 525-540页

作者： Nianxun LI Tian LI Zhiyuan dai Deng QIN Jiye ZHANG State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong UniversityChengdu 610031China

The streamlined nose length(SNL)plays a crucial role in determining the aerodynamic performance of high-speed *** appropriate SNL can not only effectively reduce the magnitude of aerodynamic drag and lift forces,but also improve the performance of the high-speed train in tunnel passing and crosswind *** this study,a numerical simulation of the aerodynamic performance of high-speed trains at a speed of 400 km/h,with varying SNLs,is conducted using the k-ωshear stress transport(SST)turbulence *** different SNLs include 6.0,7.0,8.0,9.0,9.8,12.0,15.0,and 18.0 *** order to validate the accuracy of the numerical simulation,its results are compared with wind tunnel test data obtained from the *** simulation is carried out using compressible and incompressible gases to determine the effect of gas compressibility on *** impact of SNL on the aerodynamic performance of the trains is analyzed in terms of aerodynamic forces,velocity,and pressure *** comparison to the original train,the train with a 6.0 m SNL experienced a 10.8%increase in overall aerodynamic ***,the lift forces on the head and tail cars increased by 35.7%and 75.5%,*** the other hand,the train with an 18.0 m SNL exhibited a 16.5%decrease in aerodynamic ***,the lift forces on the head and tail cars decreased by 21.9%and 49.7%,*** aerodynamic drag force of the entire train varies linearly with the SNL,while the aerodynamic lift of the tail car follows a quadratic function in relation to the SNL.

关键词： Streamlined nose length(SNL) High-speed train Aerodynamic performance Numerical simulation Flow structures

Bioactive chemical constituents from the marine-derived fungus Cladosporium ***-5

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Journal of oceanology and Limnology 2024年第3期42卷 905-914页

作者： Luting dai Qingyi XIE Jiaocen GUo Qingyun MA Li YANG Jingzhe YUAN Haofu dai Zhifang YU Youxing ZHAo College of Food Science and Technology Nanjing Agricultural UniversityNanjing 210095China Key Laboratory of Research and Development of Natural Product from Li Folk Medicine of Hainan Province Institute of Tropical Bioscience and BiotechnologyChinese Academy of Tropical Agricultural Sciences&Hainan Academy of Tropical Agricultural ResourceHaikou 571101China

A new isochromanone,cladosporinisochromanone(1),accompanied by 15 known compounds(2–16)were obtained from secondary metabolites produced by marine-derived fungus Cladosporium *** and HRESIMS spectra elucidation determined the planar structure of *** electronic circular dichroism(ECD)experiment assigned the absolute configuration of *** 1,2,4–6,and 10 displayed different degrees of neuroprotective activities on human neuroblastoma cells *** compounds(1,3–5,and 13)emerged resistance to protein tyrosine phosphatase 1B(PTP1B),further kinetic analysis and molecular docking study indicated that the most potent compound 13(IC50value of 10.74±0.61μmol/L)was found as a noncompetitive inhibitor for *** plasmon resonance(SPR)and molecular docking studies also demonstrated the interaction between compound 12 and Niemann-Pick C1 Like 1(NPC1L1),which has been identified as significant therapeutic target for *** addition,compounds 3,6,and 14 showed attractive inhibitory activity against the phytopathogenic fungi:Colletotrichum ***,library of Cladosporium metabolites is enriched and new active uses of known compounds are explored.

关键词： Cladosporium sp. marine-derived fungus neuroprotective effects protein tyrosine phosphatase 1B(PTP1B) Niemann-Pick C1 Like 1(NPC1L1) antifungal activity

Migration Behavior of Impurity Iron in Silicon Melt Under Pulsed Electric Current

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Acta Metallurgica Sinica(English Letters) 2024年第5期37卷 889-903页

作者： Mengcheng Zhou Yaxiong dai Changhao Liu Shengli Ding Xinfang Zhang School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China Guangdong Zhongnan Iron&Steel Co. Ltd.Guangdong 512123China

The impurity iron in silicon material will seriously affect the photoelectric conversion efficiency of silicon solar ***,the traditional silicon purification method has the disadvantages of long cycle,high energy consumption and serious *** this study,an efficient and green pulsed electric current purification technology is *** electromigration effect of iron elements,the current density gradient driving of iron phase,and the gravity of iron phase all affect the migration behavior of iron phase in silicon melt under pulsed electric *** of the depth of electrode insertion into the silicon melt,the solubility of iron in silicon decreases under the pulsed electric current,which helps to form the iron *** the same time,the iron phase tends to sink toward the bottom under the influence of *** the electrode is shallowly inserted,a non-uniform electric field is formed in the silicon melt,and the iron phase is mainly driven by the current density gradient to accelerate sink toward the *** the electrode is fully inserted,an approximately uniform electric field is formed in the silicon melt,and iron elements are preferentially migrated to the cathode by electromigration,forming iron phase sinking at the *** study of impurity iron migration behavior in silicon melt under pulsed electric current provides a new approach for the purification of polycrystalline silicon.

关键词： Metallurgical silicon Pulsed electric current Iron-rich phase Current density gradient Electromigration

Adhesion performance of alkali-activated material for 3-dimensional printing of tunnel linings at different temperatures

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Frontiers of Structural and Civil Engineering 2024年第1期18卷 66-79页

作者： Yaxin TAo Xiaodi dai Geert de SCHUTTER Kim Van TITTELBooM Department of Structural Engineering and Building Materials Ghent UniversityGhent 9052Belgium

Robotic-based technologies such as automated spraying or extrusion-based 3-dimensional(3D)concrete printing can be used to build tunnel linings,aiming at reducing labor and mitigating the associated safety issues,especially in the high-geothermal ***-based 3D concrete printing(3DCP)has additional advantages over automated sprayings,such as improved surface quality and no ***,the effect of different temperatures on the adhesion performance of 3D-printed materials for tunnel linings has not been *** study developed several alkali-activated slag mixtures with different activator modulus ratios to avoid the excessive use of Portland cement and enhance sustainability of 3D printable *** thermal responses of the mixtures at different temperatures of 20 and 40℃ were *** adhesion strength of the alkali-activated material was evaluated for both early and later ***,the structural evolution of the material exposed to different temperatures was *** was followed by microstructure *** indicate that elevated temperatures accelerate material reactions,resulting in improved early-age adhesion ***,higher temperatures contribute to the development of a denser microstructure and enhanced mechanical strength in the hardened stage,particularly in mixtures with higher silicate content.

关键词： alkali-activated material 3DCP tunnel lining high-geothermal environment adhesion

Bald Eagle Search optimization Algorithm Combined with Spherical Random Shrinkage Mechanism and Its Application

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Journal of Bionic Engineering 2024年第1期21卷 572-605页

作者： Wenyan Guo Zhuolin Hou Fang dai Xiaoxia Wang Yufan Qiang Department of Applied Mathematics School of ScienceXi'an University of TechnologyXian 710054ShaanxiChina

over the last two decades,stochastic optimization algorithms have proved to be a very promising approach to solving a variety of complex optimization *** eagle search optimization(BES)as a new stochastic optimization algorithm with fast convergence speed has the ability of prominent optimization and the defect of collapsing in the local *** avoid BES collapse at local optima,inspired by the fact that the volume of the sphere is the largest when the surface area is certain,an improved bald eagle search optimization algorithm(INMBES)integrating the random shrinkage mechanism of the sphere is ***,the INMBES embeds spherical coordinates to design a more accurate parameter update method to modify the coverage and dispersion of the ***,the population splits into elite and non-elite groups and the Bernoulli chaos is applied to elite group to tap around potential solutions of the *** non-elite group is redistributed again and the Nelder-Mead simplex strategy is applied to each group to accelerate the evolution of the worst individual and the convergence process of the *** results of Friedman and Wilcoxon rank sum tests of CEC2017 in 10,30,50,and 100 dimensions numerical optimization confirm that the INMBES has superior performance in convergence accuracy and avoiding falling into local optimization compared with other potential improved algorithms but inferior to the champion algorithm and ranking *** three engineering constraint optimization problems and 26 real world problems and the problem of extracting the best feature subset by encapsulated feature selection method verify that the INMBES’s performance ranks first and has achieved satisfactory accuracy in solving practical problems.

关键词： Bald eagle search optimization algorithm Spherical coordinates Chaotic variation Simplex method Encapsulated feature selection

Prenatal amoxicillin exposure induces developmental toxicity in fetal mice and its characteristics

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Journal of Environmental Sciences 2024年第3期137卷 287-301页

作者： Yongguo dai Yu Peng Wen Hu Yi Liu Hui Wang Department of Pharmacology Wuhan University School of Basic Medical SciencesWuhan 430071China Department of Pharmacy Zhongnan Hospital of Wuhan UniversityWuhan 430071China Hubei Provincial Key Laboratory of Developmentally originated Disease Wuhan 430071China

Amoxicillin,a widely used antibiotic in human and veterinary pharmaceuticals,is now considered as an“emerging contaminant”because it exists widespreadly in the environment and brings a series of adverse ***,systematic studies about the developmental toxicity of amoxicillin are still *** explored the potential effects of amoxicillin exposure on pregnancy outcomes,maternal/fetal serum phenotypes,and fetal multiple organ development in mice,at different doses(75,150,300 mg/(kg·day))during late-pregnancy,or at a dose of 300 mg/(kg·day)during different stages(mid-/latepregnancy)and courses(single-/multi-course).Results showed that prenatal amoxicillin exposure(PAmE)had no significant infuence on the body weights of dams,but it could inhibit the physical development and reduce the survival rate of fetuses,especially during the ***,PAmE altered multiple maternal/fetal serum phenotypes,especially in *** multi-organ function results showed that PAmE inhibited testicular/adrenal steroid synthesis,long bone/cartilage and hippocampal development,and enhanced ovarian steroid synthesis and hepatic glycogenesis/lipogenesis,and the order of severity might be gonad(testis,ovary)>liver>*** analysis found that PAmE-induced multiorgan developmental and functional alterations had differences in stages,courses and fetal gender,and the most obvious changes might be in high-dose,late-pregnancy and multicourse,but there was no typical rule of a dose-response *** conclusion,this study confirmed that PAmE could cause abnormal development and multi-organ function alterations,which deepens our understanding of the risk of PAmE and provides an experimental basis for further exploration of the long-term harm.

关键词： Amoxicillin Prenatal exposure Fetal development organ function Developmental toxicity

Uio-66-NH_(2)nanoparticles supported on layered double hydroxides as an excellent adsorbent for levofloxacin capture

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Particuology 2024年第9期92卷 155-165页

作者： Yan Li Heng Lin Qiaolan Yu Na Ma Wei dai College of Geography and Environmental Sciences Zhejiang Normal UniversityJinhua321004China Key Laboratory of the Ministry of Education for Advanced Catalysis Materials College of Chemistry and Materials ScienceZhejiang Normal UniversityJinhua321004China

The adsorption performances of individual adsorbent such as Uio-66-NH_(2)and MgAl-layered double hydroxides(MgAl-LDH)toward levofloxacin(LVX)is less satisfactory due to the disappointing uptake capacity and adsorption ***,a 3D flower-like composite adsorbent prepared via iterative hydrothermal synthesis method anchoring Uio-66-NH_(2)nanoparticles onto the MgAl-LDH *** to the synergistic effects of Uio-66-NH_(2),and MgAl-LDH,the MgAl-LDH@Uio-66-NH_(2)exhibits an outstanding adsorption performance toward ***,the maximum LVX uptake capacity over MgAl-LDH@Uio-66-NH_(2)reached 268 mg/g,which was higher than that of the individual adsorption materials Uio-66-NH_(2)(41 mg/g),MgAl-LDH(140 mg/g),and some adsorbents reported in previous *** rapid adsorption process can reach equilibrium within 20 min,which conformed well to the pseudo-second-order kinetics and the Langmuir isotherm *** thermodynamic result also indicated that the adsorption was spontaneous and exothermic,simultaneous coexisting physical and chemical adsorption ***,the MgAl-LDH@Uio-66-NH_(2)still maintained excellent adsorption capacity with a slightly decrease after fifth cycle,exhibiting a remarkable reuse and stable *** work provides a highly novel strategy to prepare recyclable composite adsorbent for the LVX capture from aqueous solution.

关键词： Layered double hydroxides Uio-66-NH_(2) LVX Adsorption

Research on the Control Strategy of Micro Wind-Hydrogen Coupled System Based on Wind Power Prediction and Hydrogen Storage System Charging/Discharging Regulation

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Energy Engineering 2024年第6期121卷 1607-1636页

作者： Yuanjun dai Haonan Li Baohua Li College of Machine Shanghai DianJi UniversityShanghai201306China

This paper addresses the micro wind-hydrogen coupled system,aiming to improve the power tracking capability of micro wind farms,the regulation capability of hydrogen storage systems,and to mitigate the volatility of wind power generation.A predictive control strategy for the micro wind-hydrogen coupled system is proposed based on the ultra-short-term wind power prediction,the hydrogen storage state division interval,and the daily scheduled output of wind power *** control strategy maximizes the power tracking capability,the regulation capability of the hydrogen storage system,and the fluctuation of the joint output of the wind-hydrogen coupled system as the objective functions,and adaptively optimizes the control coefficients of the hydrogen storage interval and the output parameters of the system by the combined sigmoid function and particle swarm algorithm(sigmoid-PSo).Compared with the real-time control strategy,the proposed predictive control strategy can significantly improve the output tracking capability of the wind-hydrogen coupling system,minimize the gap between the actual output and the predicted output,significantly enhance the regulation capability of the hydrogen storage system,and mitigate the power output fluctuation of the wind-hydrogen integrated system,which has a broad practical application prospect.

关键词： Micro wind-hydrogen coupling system ultra-short-term wind power prediction sigmoid-PSo algorithm adaptive roll optimization predictive control strategy