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Finite Element Simulation and Experimental Study on Vibration Characteristics of Converter Transformer Under DC Bias

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Protection and Control of Modern Power Systems 2024年第4期9卷 110-125页

作者： hao Wang li Zhang Youliang Sun liang Zou the School of Electrical Engineering Shandong Uni-versityJinan 250061China the School of Electrical Engineering Shandong UniversityJinan 250061China Shandong Power Equipment Co. Ltd.Jinan 250101China

To clarify the electromagnetic,vibration,and loss characteristics of the internal components of a converter transformer under DC bias conditions and their influencing mechanisms,a series of studies are conducted using the finite element method and model *** paper quantifies the influence of different DC contents on the magnetic flux density,force,and displacement distribution characteristics of the iron core and winding and analyzes the internal relationship between various *** inflection point of the DC bias coefficient on the vibration is obtained and the contribution mechanism of the different responses of the iron core and winding to this inflection point is *** value of the DC bias coefficient for changing the main vibration frequency is *** the DC bias coefficient is 1.0 and 1.5,the main frequency of vibration moves to the right to 250 Hz and 350 *** on the principle of similarity,a DC bias vibration experimental platform for converter transformers is developed,and DC bias magnetic experiments are conducted to verify the reliability of the simulation results.

关键词： DC bias converter transformer finite element and experimental analysis

Numerical Study on the Effect of Vortex Generators on the Aerodynamic Drag of a High-Speed Train

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Fluid Dynamics & Materials Processing 2024年第2期20卷 463-473页

作者： Tian li hao liang Zerui Xiang Jiye Zhang State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong UniversityChengdu610031China School of Design Southwest Jiaotong UniversityChengdu610031China

A relatively high aerodynamic drag is an important factor that hinders the further acceleration of high-speed *** the shear stress transport(SST)k-ωturbulence model,the effect of various vortex generator types on the aerodynamic characteristics of an ICE2(Inter-city Electricity)train has been *** results indi-cate that the vortex generators with wider triangle,trapezoid,and micro-ramp arranged on the surface of the tail car can signiﬁcantly change the distribution of surface pressure and affect the vorticity intensity in the *** alteration effectively reduces the resistance of the tail ***,the micro-ramp vortex generator with its convergent structure at the rear exhibits enhancedﬂow-guiding capabilities,resulting in a 15.4%reduction in the drag of the tail car.

关键词： Vortex generator aerodynamic drag reduction numerical simulation

Atomic force microscopy-based nanoscale infrared techniques for liquid environments

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Science Bulletin 2024年第2期69卷 151-153页

作者： Jian li Jing liang Mu-hao Lan Xing-Hua Xia State Key Laboratory of Analytical Chemistry for life Science School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023China

Infrared(IR)light energy matches well with the vibration and rotation of chemical bonds in molecules,hence IR spectroscopy is commonly used for accurate molecular identification[1].Conventional IR analysis involves bulk samples,providing averaged information of the entire *** spatially-resolved investigation of heterogeneous sample properties is constrained by the micrometer-level spatial resolution of optical IR microscopy.

关键词： spatially hence rotation

A target parameter estimation method via atom-reconstruction in radar mainlobe jamming

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Journal of Systems Engineering and Electronics 2024年第2期35卷 350-360页

作者： ZHOU Bilei liU Weijian li Rongfeng CHEN Hui ZHANG liang DU Qinglei li Binbin CHEN hao Air Force Early Warning Academy Wuhan 430019China Aerospace Nanhu Electronic Information Technology Co. Ltd.Jingzhou 434000China

Mainlobe jamming(MLJ)brings a big challenge for radar target detection,tracking,and *** suppression of MLJ is a hard task and an open problem in the electronic counter-counter measures(ECCM)*** parameters and target direction estimation is difficult in radar MLJ.A target parameter estimation method via atom-reconstruction in radar MLJ is proposed in this *** proposed method can suppress the MLJ and simultaneously provide high estimation accuracy of target range and ***,the eigen-projection matrix processing(EMP)algorithm is adopted to suppress the MLJ,and the target range is estimated effectively through the beamforming and pulse *** the target angle can be effectively estimated by the atom-reconstruction *** any prior knowledge,the MLJ can be canceled,and the angle estimation accuracy is well ***,the proposed method does not have strict requirement for radar array construction,and it can be applied for linear array and planar ***,the proposed method can effectively estimate the target azimuth and elevation simultaneously when the target azimuth(or elevation)equals to the jamming azimuth(or elevation),because the MLJ is suppressed in spatial plane dimension.

关键词： mainlobe jamming anti-jamming atom-reconstruction radar

Metabolomic-based analysis reveals bile acid-mediated ovarian failure induced by low temperature in zebrafish

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Zoological Research 2024年第4期45卷 791-804页

作者： Wen-hao li Zhi-Qiang li Meng-Di Bu Jia-Zhen li liang-Biao Chen Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources Ministry of EducationCollege of Fisheries and Life SciencesShanghai Ocean UniversityShanghai 201306China Laboratory for Marine Biology and Biotechnology Qingdao National Laboratory for Marine Science and TechnologyQingdaoShandong 266237China International Research Center for Marine Biosciences Ministry of Science and TechnologyCollege of Fisheries and Life SciencesShanghai Ocean UniversityShanghai 201306China

As ectotherms, fish are highly sensitive to temperature fluctuations, which can profoundly impact their reproductive cycles. In this study, we investigated the fertility and histological characteristics of zebrafish(Danio rerio) ovaries exposed to a temperature gradient ranging from the thermopreferendum temperature of the species,27℃, to lower temperatures of 22℃, 20℃, and 13℃ over a period of two weeks. Comparative metabolomic(six biological replicates for each temperature) and transcriptomic(four biological replicates for each temperature) analyses were conducted under the four temperature conditions. Results indicated that lower temperatures inhibited oocyte development and differential metabolites were involved in steroid hormone production,antioxidant function, and lipid and protein *** reproductive hormones, increased proteolysis,and lipid degradation significantly impeded oocyte development and egg maturation. Notably, a significant increase in bile acid content was noted in the ovaries of the cold-treated fish, indicating that bile acids play a critical role in ovarian failure. Overall, these findings provide valuable insights into the mechanisms governing the reproductive response of fish to cold stress.

关键词： old stress Ovarian failure Metabolome Zebrafish

Rational Design of Cost-Effective Metal-Doped ZrO_(2)for Oxygen Evolution Reaction

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Nano-Micro Letters 2024年第9期16卷 385-396页

作者： Yuefeng Zhang Tianyi Wang liang Mei Ruijie Yang Weiwei Guo hao li Zhiyuan Zeng Department of Materials Science and Engineering and State Key Laboratory of Marine PollutionCity University of Hong Kong83 Tat Chee AvenueKowloon 999077Hong KongPeople’s Republic of China Advanced Institute for Materials Research(WPI‑AIMR) Tohoku UniversitySendai 980‑8577Japan Shenzhen Research Institute City University of Hong KongShenzhen 518057People’s Republic of China Shanxi Supercomputing Center Lvliang 033000ShanxiPeople’s Republic of China

The design of cost-effective electrocatalysts is an open challenging for oxygen evolution reaction(OER)due to the“stable-oractive”*** dioxide(ZrO_(2)),a versatile and low-cost material that can be stable under OER operating conditions,exhibits inherently poor OER activity from experimental ***,we doped a series of metal elements to regulate the ZrO_(2)catalytic activity in OER via spin-polarized density functional theory calculations with van der Waals *** modeling as a function of the OER activity descriptor(G_(O*)-G_(HO*))displays that 16 metal dopants enable to enhance OER activities over a thermodynamically stable ZrO_(2)surface,among which Fe and Rh(in the form of single-atom dopant)reach the volcano peak(*** optimal activity of OER under the potential of interest),indicating excellent OER *** energy diagram calculations,density of states,and ab initio molecular dynamics simulations further showed that Fe and Rh are the effective dopants for ZrO_(2),leading to low OER overpotential,high conductivity,and good *** cost-effectiveness,single-atom Fe doped ZrO_(2)emerged as the most promising catalyst for *** finding offers a valuable perspective and reference for experimental researchers to design cost-effective catalysts for the industrial-scale OER production.

关键词： Oxygen evolution reaction Metal oxide Electrocatalysis Surface Pourbaix analysis Doping

Human brain organoid:trends,evolution,and remaining challenges

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Neural Regeneration Research 2024年第11期19卷 2387-2399页

作者： Minghui li Yuhan Yuan Zongkun Hou Shilei hao liang Jin Bochu Wang Key Laboratory of Biorheological Science and Technology Ministry of EducationCollege of BioengineeringChongqing UniversityChongqingChina Southwest Hospital/Southwest Eye Hospital Third Military Medical University(Army Medical University)ChongqingChina School of Biology and Engineering/School of Basic Medical Sciences Guizhou Medical UniversityGuiyangGuizhou ProvinceChina

Advanced brain organoids provide promising platforms for deciphering the cellular and molecular processes of human neural development and *** various studies and reviews have described developments and advancements in brain organoids,few studies have comprehensively summarized and analyzed the global trends in this area of *** identify and further facilitate the development of cerebral organoids,we utilized bibliometrics and visualization methods to analyze the global trends and evolution of brain organoids in the last 10 ***,annual publications,countries/regions,organizations,journals,authors,co-citations,and keywords relating to brain organoids were *** hotspots in this field were also systematically ***,current applications for brain organoids in neuroscience,including human neural development,neural disorders,infectious diseases,regenerative medicine,drug discovery,and toxicity assessment studies,are comprehensively *** that end,several considerations regarding the current challenges in brain organoid research and future strategies to advance neuroscience will be presented to further promote their application in neurological research.

关键词： bibliometric analysis brain organoids cerebral organoids global trends neuroscience

Review on dietary supplements as an effective improvement of Alzheimer's disease:focus on structures and mechanisms

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Food Science and Human Wellness 2024年第4期13卷 1787-1805页

作者： Sheng li Yinling Wei Zhenzhen liang lingli Guo Xiaojiang hao Yu Zhang State Key Laboratory of Phytochemistry and Plant Resources in West China Kunming Institute of BotanyChinese Academy of SciencesKunming 650201China College of Traditional Chinese Materia Medica Shenyang Pharmaceutical UniversityShenyang 110016China

Alzheimer’s disease(AD),the major form of neurodegenerative diseases that can severely impede normal cognitive function,makes it one of the most common fatal *** are currently over 50 million AD patients *** neuropathology of AD is perplexing and there is a scarcity of disease-modifying ***,early diagnosis of AD has been made possible with the discovery of biological markers associated with pathology,providing strong support for the improvement of the disease *** search for inhibitors of AD markers from dietary supplements(DSs)has become a major hot *** with the widespread use of DSs,DSs containing polyphenols,alkaloids,terpenes,polysaccharides and other bioactive components can prevent AD by reducing Aβdeposition,inhibiting tau protein hyperphosphorylation,reconstructing synaptic dysfunction,weakening cholinesterase activity,regulating mitochondrial oxidative stress,neuronal inflammation and *** review summarizes the anti-AD effects of the main DSs and their bioactive constituents,as well as the potential molecular mechanisms covers from 2017 to ***,we discussed the opportunities and challenges faced by DSs in the process of AD prevention and treatment,aiming to further provide new perspectives for functional food development.

关键词： Dietary supplements Bioactive ingredients Alzheimer’s disease Mechanism of action

Polyelectrolyte Complexes and Coacervates Formed by De novo-Designed Peptides and Oligonucleotide

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Chinese Journal of Polymer Science 2024年第9期42卷 1333-1340,I0007页

作者： Tian-hao Ren De-Hai liang Beijing National Laboratory for Molecular Sciences Department of Polymer Science and Engineering and the Key Laboratory of Polymer Chemistry and Physics of the Ministry of EducationCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing100871China

The liquid-liquid phase separation of biopolymers in living cells contains multiple interactions and occurs in a dynamic *** the regulation mechanism is still a *** this work,we designed a series of peptides(XXLY)_(6)SSSGSS and studied their complexation and coacervation behavior with single-stranded ***“X”and“Y”are varied to combine known amounts of charged and non-charged amino acids,together with the introduction of secondary structures and pH *** show that the electrostatic interaction,which is described as charge density,controls both the strength of complexation and the degree of chain relaxation,and thus determines the growth and size of the *** hydrophobic interaction is prominent when the charges are ***,the secondary structures of peptides exhibit profound effect on the morphology of the phases,such as solid phase to liquid phase *** study gains insight into the phase separation under physiological *** is also helpful to create coacervates with desirable structures and functions.

关键词： Polyelectrolyte complex Coacervate Peptides Secondary structure Electrostatic interaction