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Numerical Simulation of Droplet Generation in Coaxial Microchannels

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Fluid Dynamics & Materials Processing 2024年第3期20卷 487-504页

作者： Zongjun yin Rong Su hui Xu School of Mechanical Engineering Anhui Institute of Information TechnologyWuhu241100China

In this study,numerical simulations of the pinching-off phenomena displayed by the dispersed phase in a continuous phase have been conducted using COMSOL Multiphysics(level-set method).Four flow patterns,namely“drop flow”,“jet flow”,“squeeze flow”,and“co-flow”,have been obtained for different flow velocity ratios,channel diameter ratios,density ratios,viscosity ratios,and surface *** flow pattern map of two-phase flow in coaxial microchannels has been obtained accordingly,and the associated droplet generation process has been critically discussed considering the related frequency,diameter,and pinch-off *** particular,it is shown that the larger the flow velocity ratio,the smaller the diameter of generated droplets and the shorter the pinch-off *** pinch-off length of a droplet is influenced by the channel diameter ratio and density *** changes in viscosity ratio have a negligible influence on the droplet generation pinching *** an increase in surface tension,the frequency of generation and pinch-off length of droplets decrease,but for small surface tension the generation diameter of droplet increases.

关键词： Droplet generation characteristics coaxial microchannels flow patterns pinch-off length

Tuning heterogeneous microstructures to enhance mechanical properties of nano-TiN particle reinforced Haynes 230 composites by laser powder bed fusion

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Rare Metals 2024年第9期43卷 4548-4565页

作者： Wen-Jie Liu hui Li Qian-Xing yin He-Jun Du School of Power and Mechanical Engineering Wuhan University The Institute of Technological Sciences Wuhan University School of Mechanical&Aerospace Engineering Nanyang Technological University

Laser powder bed fusion(LPBF) is considered to be one of the most promising additive manufacturing technologies for producing components with geometries and high geometrical precision that are unattainable by traditional technologies. The superalloy exhibits exceptional mechanical and high-temperature performances,rendering it a prime candidate for advanced aero-engine applications. Despite the high demand for LPBF-manufactured superalloys, the superalloy is one of the materials manufactured difficultly by LPBF due to their large laser absorptivity fluctuation, poor molten pool stability and sharp temperature gradient. Hence, superalloys are characterized by severe pores, undesirable coarse columnar grains and poor mechanical properties. In this work, the effect of nano-Ti N particles on defects, molten pool characteristics and microstructure and performance of the composites were investigated. The 4.5 wt% Ti N/Haynes230 samples exhibited exceptional nanohardness and elastic modulus with maximum values reaching 5.53 GPa and 240.03 GPa, respectively. These superior mechanical properties were attributed to the combined effects of spatter and gas pore inhibition, grain refinement and duplex nanophases strengthening. Moreover, the stability of molten pool was enhanced, and spatter was effectively suppressed by adding nano-Ti N particles, while grain refinement and columnar to equiaxed transitions were promoted. Furthermore, the matrix exhibited a high dislocation density due to a significant hindrance of dislocation movement caused by massive nano-phases(e.g., Ti N and M23C6), resulting in the formation of extensive dislocation tangles and *** work offers novel insights into the role of nanoparticles reinforced superalloy composites by LPBF.

关键词： Composites Laser powder bed fusion Mechanical properties Microstructure Molten pool characteristics

Accurate characterization of bubble mixing uniformity in a circular region using computational geometric theory

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Particuology 2024年第3期86卷 149-159页

作者： hui Sun Jianxin Xu Shibo Wang Guangcheng Cai Hua Wang Wuliang yin State Key Laboratory ofComplex Nonferrous Metal Resources Clean Utilization Kunming University ofScience and TechnologyKunming650093China bFaulty of Metallurgical and Energy Engineering Kunming University ofScience and TechnologyKunming650093China Faculty of Science Kunming University ofScience and TechnologyKunming650500China Department of Elec.and Electronic Engineering.University of Manchester ManchesterM139PL UK

The present study proposes a novel method based on the geometric theory for measuring the distribution of bubble swarms in the circular region of a direct-contact heat *** was determined that the mixing is uniform when the average distance between the bubble swarms in the unit circular region is approximately 0.9054,which is the standard reference *** effect of sample size(i.e.,the number of bubbles)on mixing uniformity was investigated to determine the optimal sample *** was verified that the metric's accuracy and stability were higher with a sample size of ***,it was proposed to increase the sample size by filling irregular bubbles using a segmentation method,which enabled a further accurate assessment of the mixing *** mixing uniformity of bubble swarms in the circular region and its maximum internal connection with the square region was accurately *** was revealed that the relative average error increased by approximately 3.47% due to information *** proposed method was demonstrated to be rotationally *** present study provided novel insights into evaluating mixing uniformity,which would guide enhanced heat transfer and the effective evaluation of the spatiotemporal characteristics of transient mixing in circular regions or the cross-sections of chemical transport pipelines.

关键词： Direct-contact heat exchanger Circular region Bubble swarm Distribution uniformity AD-Circle method

LncRNA pol-lnc78 as a ceRNA regulates antibacterial responses via suppression of pol-miR-n199-3p-mediated SARM down-regulation in Paralichthys olivaceus

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Zoological Research 2024年第1期45卷 25-35页

作者： Xian-hui Ning Bing Han Ye Peng Shao-Wu yin College of Marine Science and Engineering Nanjing Normal UniversityNanjingJiangsu 210023China CAS Key Laboratory of Experimental Marine Biology Center for Ocean Mega-ScienceInstitute of OceanologyChinese Academy of SciencesQingdaoShandong 266071China Co-Innovation Center for Marine Bio-Industry Technology of Jiangsu Province LianyungangJiangsu 222005China

Long non-coding RNAs(lncRNAs)function as key modulators in mammalian immunity,particularly due to their involvement in lncRNA-mediated competitive endogenous RNA(ceRNA)*** their recognized significance in mammals,research on lncRNAs in lower vertebrates remains *** the present study,we characterized the first immune-related lncRNA(pol-lnc78)in the teleost Japanese flounder(Paralichthys olivaceus).Results indicated that pol-lnc78 acted as a ceRNA for pol-miR-n199-3p to target the sterile alpha and armadillo motif-containing protein(SARM),the fifth discovered member of the Toll/interleukin 1(IL-1)receptor(TIR)adaptor *** ceRNA network regulated the antibacterial responses of flounder via the Toll-like receptor(TLR)signaling ***,SARM acted as a negative regulator and exacerbated bacterial infection by inhibiting the expression of inflammatory cytokines IL-1βand tumor necrosis factor-α(TNF-α).Pol-miR-n199-3p reduced SARM expression by specifically interacting with the 3’untranslated region(UTR),thereby promoting SARM-dependent inflammatory cytokine expression and protecting the host against bacterial ***,pol-lnc78 sponged pol-miR-n199-3p to ameliorate the inhibition of SARM *** infection,the negative regulators pol-lnc78 and SARM were significantly down-regulated,while pol-miR-n199-3p was significantly up-regulated,thus favoring host antibacterial *** findings provide novel insights into the mechanisms underlying fish immunity and open new horizons to better understand ceRNA crosstalk in lower vertebrates.

关键词： LncRNA SARM miRNA ceRNA Antibacterial response

USP19 Stabilizes TAK1 to Regulate High Glucose/Free Fatty Acid-induced Dysfunction in HK-2 Cells

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当代医学科学（英文） 2024年第4期44卷 707-717页

作者： Xiao-hui YAN yin-na ZHU Yan-ting ZHU Kidney Disease and Dialysis Center Shaanxi Provincial People's HospitalXi'an 710068China Department of Nephrology The Third Affiliated Hospital of Xi'an Medical UniversityXi'an 710000China Nephrology and Hemodialysis Center Shaanxi Provincial People's HospitalXi'an 710068China

Objective:Obesity-induced kidney injury contributes to the development of diabetic nephropathy(DN).Here,we identified the functions of ubiquitin-specific peptidase 19(USP19)in HK-2 cells exposed to a combination of high glucose(HG)and free fatty acid(FFA)and determined its association with TGF-beta-activated kinase 1(TAK1).Methods:HK-2 cells were exposed to a combination of HG and ***19 mRNA expression was detected by quantitative RT-PCR(qRT-PCR),and protein analysis was performed by immunoblotting(IB).Cell growth was assessed by Cell Counting Kit-8(CCK-8)viability and 5-ethynyl-2'-deoxyuridine(EdU)proliferation *** cycle distribution and apoptosis were detected by flow *** USP19/TAK1 interaction and ubiquitinated TAK1 levels were assayed by coimmunoprecipitation(Co-IP)assays and ***:In HG+FFA-challenged HK-2 cells,USP19 was highly ***19 knockdown attenuated HG+FFA-triggered growth inhibition and apoptosis promotion in HK-2 ***,USP19 knockdown alleviated HG+FFA-mediated PTEN-induced putative kinase 1(PINK1)/Parkin pathway inactivation and increased mitochondrial reactive oxygen species(ROS)generation in HK-2 ***,USP19 stabilized the TAK1 protein through ***,increased TAK1 expression reversed the USP19 knockdown-mediated phenotypic changes and PINKl/Parkin pathway activation in HG+FFA-challenged HK-2 ***:The findings revealed that USP19 plays a crucial role in promoting HK-2 cell dysfunction induced by combined stimulation with HG and FFAs by stabilizing TAK1,providing a potential therapeutic strategy for combating DN.

关键词： HK-2 cells USP19 deubiquitination dysfunction free fatty acid high glucose

FPGA implementation of 500-MHz high-count-rate high-time-resolution real-time digital neutron-gamma discrimination for fast liquid detectors

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Nuclear Science and Techniques 2024年第8期35卷 101-113页

作者： hui‑yin Shen Jing‑Long Zhang Jie Zhang Jian‑Hang Zhou College of Nuclear Technology and Automation Engineering Chengdu University of TechnologyChengdu 610059China Southwestern Institute of Physics P.O.Box 432Chengdu 610041China

Fast neutron flux measurements with high count rates and high time resolution have important applications in equipment such as *** this study,real-time neutron and gamma discrimination was implemented on a self-developed 500-Msps,12-bit digitizer,and the neutron and gamma spectra were calculated directly on an FPGA.A fast neutron flux measurement system with BC-501A and EJ-309 liquid scintillator detectors was developed and a fast neutron measurement experiment was successfully performed on the HL-2 M tokamak at the Southwestern Institute of Physics,*** experimental results demonstrated that the system obtained the neutron and gamma spectra with a time accuracy of 1 *** count rates of up to 1 Mcps,the figure of merit was greater than 1.05 for energies between 50 keV and 2.8 MeV.

关键词： Neutron-gamma discrimination Liquid scintillation detector Real-time spectrum analyzer

Mitigation of Deane and Hamill phenomenon in gallium nitride high-voltage power supply for electric propulsion system application

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High Voltage 2024年第1期9卷 252-265页

作者： Minghai Dong hui Li Shan yin Kye Yak See yingzhe Wu Xiong Xin School of Aeronautics&Astronautics University of Electronic Science and Technology of ChinaChengduChina School of Electrical&Electronic Engineering Nanyang Technological UniversitySingaporeSingapore School of Automation Engineering University of Electronic Science and Technology of ChinaChengduChina Innoscience(Shenzhen)Semiconductor Co.Ltd. ShenzhenChina

The step-up resonant converters are widely adopted to provide high voltage in kV-level for electric propulsion system due to their high efficiency,low mass,modularisation,and high-power *** bipolar Cockcroft-Walton voltage multiplier(BiCWVM)is a major circuit that steps up the voltage in the resonant ***,the diode nonlinearity in BiCWVM can introduce self-sustained quasi-periodic oscillations in the voltage and current waveforms,which is commonly known as the Deane and Hamill(DH)*** oscillation can lead to higher magnetic loss and control failure,and it is more likely to present in the gallium nitride-based converter due to the highfrequency *** authors aim to investigate and mitigate the DH phenomenon systematically so that proper mitigation can be *** facilitate the investigation,the circuit before the BiCWVM in the converter is derived and modelled as a voltage source v_(m)and a series inductor L_(sy).Also,the reverse recovery process of the diode in the BiCWVM can be represented by a piecewise-linear(PWL)model,with the simplified circuit and PWL model,the relationship between voltage and current under different operating conditions can be determined with *** relationship allows to understand the mechanism of diode reverse recovery in BiCWVM that leads to DH ***,a hybrid-/full-silicon carbide(SiC)design is proposed to mitigate the DH phenomenon,which is verified experimentally for a 300-kHz,5-W,20-V/1.5-kV GaN-based step-up resonant converter.

关键词： power resonant high

Constructing a 3D multichannel structure to enhance performance of Ni–Co–Mn hydroxide electrodes for flexible supercapacitors

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Rare Metals 2024年第1期43卷 148-163页

作者： Zhi-hui Xu Shi-Shuai Sun Xue-Lei Li Zhi-hui Zhang Hai-ying Li Shuang-Ting Ruan Shou-Gen yin Key Laboratory of Display Materials and Photoelectric Devices(Ministry of Education)and Tianjin Key Laboratory for Photoelectric Materials and Devices School of Materials Science and EngineeringTianjin University of TechnologyTianjin 300384China College of Science Tianjin University of TechnologyTianjin 300384China School of Materials Science and Engineering Inner Mongolia University of TechnologyHohhot 010051China

The balancing of the electrochemical performance,mechanical stability,and processing technology for applying supercapacitors to flexible and wearable electronics continues to encounter severe ***,we prepare Ni-Co-Mn hydroxide electrodes with a threedimensional multichannel structure via a simple hydrothermal *** are constructed using vertically contiguous nano sheets with a uniform thickness and rough *** electrodes can provide numerous electroactive sites and accelerate the transmission of electrolyte *** relationship between the structure and electrochemical performances is verified by experiments and theoretical ***-dimensional(2D)planar and one-dimensional(1D)fiber electrodes are prepared using a flexible carbon cloth(CC)and carbon fiber(CF),respectively,as *** assembled quasi-solid-state flexible asymmetric supercapacitor(FASC)with a twodimensional sandwich structure using NiCoMn-OH/CC as the electrode achieves a remarkable energy density of73.8 Wh·kg^(-1)at a power density of 1.03 kW·kg^(-1).The quasi-solid-state FASC with a 1D linear structure using NiCoMn-OH/CF as the electrode also attains a high energy density(12.9 Wh·kg^(-1)at a power density of0.75 W·kg^(-1)).Moreover,the electrochemical performances of the NiCoMn/CC//AC/CC and NiCoMn/CF//AC/CF FASCs are not disturbed at different bending angles(0°,45°,90°,135°and 180°),This indicates the superior flexibility of the *** also assemble a self-powered energy-harvesting storage system by integrating FASCs and commercial solar cells to verify its *** displays sustainable development potential for energy storage.

关键词： Supercapacitors Flexible Ni–Co–Mn hydroxide 3D multichannel structure High performances

Centrifuge modeling of unreinforced and multi-row stabilizing piles reinforced landslides subjected to reservoir water level fluctuation

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第5期16卷 1600-1614页

作者： Chenyang Zhang Yueping yin hui Yan Sainan Zhu Ming Zhang Luqi Wang Department of Civil Engineering The University of Hong KongHong KongChina China Institute of Geo-environment Monitoring BeijingChina Chongqing 107 Municipal Construction Engineering Co. Ltd.ChongqingChina Faculty of Engineering China University of GeosciencesWuhanChina School of Civil Engineering Chongqing UniversityChongqingChina

With the construction of the Three Gorges Reservoir dam,frequent reservoir landslide events have been *** recent years,multi-row stabilizing piles(MRSPs)have been used to stabilize massive reservoir landslides in *** this study,two centrifuge model tests were carried out to study the unreinforced and MRSP-reinforced slopes subjected to reservoir water level(RWL)operation,using the Taping landslide as a *** results indicate that the RWL rising can provide lateral support within the submerged zone and then produce the inward seepage force,eventually strengthening the slope ***,a rapid RWL drawdown may induce outward seepage forces and a sudden debuttressing effect,consequently reducing the effective soil normal stress and triggering partial pre-failure within the RWL fluctuation ***,partial deformation and subsequent soil structure damage generate excess pore water pressures,ultimately leading to the overall failure of the reservoir *** study also reveals that a rapid increase in the downslope driving force due to RWL drawdown significantly intensifies the lateral earth pressures exerted on the ***,the MRSPs possess a considerable reinforcement effect on the reservoir landslide,transforming the overall failure into a partial deformation and failure situated above and in front of the *** mechanical transfer behavior observed in the MRSPs demonstrates a progressive alteration in relation to RWL *** the RWL rises,the mechanical states among MRSPs exhibit a growing *** shear force transfer factor(*** ratio of shear forces on pile of the n th row to that of the first row)increases significantly with the RWL *** indicates that the mechanical states among MRSPs tend toward an enhanced *** insights gained from this study contribute to a more comprehensive understanding of the failure mechanisms of reservoir landslides and the mechanical behavior of M

关键词： Reservoir landslide Failure mechanism Multi-row stabilizing piles Mechanical behavior