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CFD-PBM coupled modeling of the liquid-liquid dispersion characteristics and structure optimization for Kenics static mixer

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Chinese Journal of Chemical Engineering 2024年第6期70卷 173-188页

作者： Junhai Deng Shilin Lan Juchang Wu Shenghua Du Weidong liu Luchang Han Yefeng Zhou National&Local United Engineering Research Centre for Chemical Process Simulation and Intensification Chemical Process Simulation and Optimization Engineering Research Center of Ministry of EducationXiangtan UniversityXiangtan 411105China Hunan Haili Chemical Industry Company Limited Changsha 410000China

Kenics static mixers(KSM)are extensively used in industrial mixing-reaction processes by virtue of high mixing efficiency,low power homogenization and easy continuous *** liquid droplet size and its distribution and thus revealing the dispersion characteristics are of great significance for structural optimization and process intensification in the *** this work,a computational fluid dynamics-population balance model(CFD-PBM)coupled method is employed to systematically investigate the effects of operating conditions and structural parameters of KSM on droplet size and its distribution,to further reveal the liquid-liquid dispersion *** indicate that higher Reynolds numbers or higher dispersed phase volume fractions increase energy dissipation,reducing Sauter mean diameter(SMD)of dispersed phase droplets and with a shift in droplet size distribution(DSD)towards smaller *** aspect ratios,greater blade twist and assembly angles amplify shear rate,leading to smaller droplet size and a narrower DSD in the smaller *** degree of impact exerted by the aspect ratio is notably ***,mixing elements with different spin enhance shear and stretching *** to the same spin,SMD becomes 3.7-5.8 times smaller in the smaller size range with a significantly narrower *** into account the pressure drop and efficiency in a comprehensive manner,optimized structural parameters for the mixing element encompass an aspect ratio of 1-1.5,a blade twist angle of 180°,an assembly angle of 90°,and interlaced assembly of adjacent elements with different *** work provides vital theoretical underpinning and future reference for enhancing KSM performance.

关键词： CFD Population balance Liquid-liquid dispersion Kenics static mixer

J-family genes redundantly regulate flowering time and increase yield in soybean

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The Crop Journal 2024年第3期12卷 944-949页

作者： Haiyang Li Zheng Chen Fan Wang Hongli Xiang Shuangrong liu Chuanjie Gou Chao Fang Liyu Chen Tiantian Bu Fanjiang Kong Xiaohui Zhao Baohui liu Xiaoya Lin Guangdong Key Laboratory of Plant Adaptation and Molecular Design/Guangzhou Key Laboratory of Crop Gene Editing/Innovative Center of Molecular Genetics and Evolution School of Life SciencesGuangzhou UniversityGuangzhou 510006GuangdongChina

Soybean(Glycine max)is a short-day crop whose flowering time is regulated by *** longjuvenile trait extends its vegetative phase and increases yield under short-day *** variation in J,the major locus controlling this trait,modulates flowering *** report that the three J-family genes influence soybean flowering time,with the triple mutant Guangzhou Mammoth-2 flowering late under short days by inhibiting transcription of E1-family genes.J-family genes offer promising allelic combinations for breeding.

关键词： Soybean Flowering time Yield J-family genes

Electrical discharge and arc milling with automatic tracking of optimal flushing direction:A novel high-efficiency compound machining method

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Chinese Journal of Aeronautics 2024年第3期37卷 351-364页

作者： Xinlei WU Yonghong liu Pengxin ZHANG Liang QI Dege LI Chi MA Renjie JI College of Mechanical and Electronic Engineering China University of Petroleum(East China)Qingdao 266580China School of Mechanical and Power Engineering Nanjing Tech UniversityNanjing 211816China

The arc milling method has the advantages of high machining efficiency and low cost and is independent of the strength and hardness of machined ***,frequent electrode back-offs and the risk of workpiece burning may occur if erosion products are not removed *** this study,it was found that the flushing method of the working medium had a significant impact on the machining performance of arc *** on this,a novel highefficiency compound machining method of electrical discharge and arc milling with automatic tracking of the optimal flushing direction was *** automatic tracking optimizer for external working medium injection was designed to determine the optimal external flushing direction according to the feed *** influence of flushing methods,working mediums,and machining parameters on the machining efficiency,tool electrode wear rate,machining error,and surface integrity of titanium alloys were *** results indicated that better machining performance and environmental friendliness were achieved using the compound flushing method of outer compressed air and inner deionized ***,the automatic tracking flushing method in the opposite direction of the feed direction showed superior results compared to other *** material removal rate with the opposite direction injection could be increased up to 1.62 times that of the same direction,and the relative electrode wear rate could be reduced by 14.76%.This novel method has broad application prospects for machining parts with difficult-to-cut materials in aerospace and military industries.

关键词： Arc milling Dielectric Difficult-to-cut materials Electric discharge machining Erosion Material removal rate

Molecular simulation study on the evolution process of hydrate residual structures into hydrate

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Chinese Journal of Chemical Engineering 2024年第5期69卷 79-91页

作者： Liwei Cheng Yunfei Li Jinlong Cui Huibo Qin Fulong Ning Bei liu Guangjin Chen Faculty of Engineering China University of GeosciencesWuhan 430074China State Key Laboratory of heavy Oil Processing China University of PetroleumBeijing 102249China College of Science Nanchang Institute of TechnologyNanchang 330099China School of Chemical Engineering Guangdong University of Petrochemical TechnologyMaoming 525000China National Center for International Research on Deep Earth Drilling and Resource Development China University of Geosciences(Wuhan)Wuhan 430074China

The clathrate hydrate memory effect is a fascinating phenomenon with potential applications in carbon capture,utilization and storage(CCUS),gas separation,and gas storage as it can accelerate the secondary formation of clathrate ***,the underlying mechanism of this effect remains *** gain a better understanding of the mechanism,we conducted molecular dynamic simulations to simulate the initial formation and reformation processes of methane *** this work,we showed the evolution process of hydrate residual structures into hydrate *** simulation results indicate that the residual structures are closely related to the existence of hydrate memory effect,and the higher the contribution of hydrate dissociated water to the hydrate nucleation process,the faster the hydrate *** hydrate dissociation,the locally ordered structures still exist after hydrate dissociation and can promote the formation of cluster structures,thus accelerating hydrate ***,the nucleation process of hydrate and the formation process of clusters are *** size of clusters composed of cup-cage structures is critical for hydrate *** residence time at high temperature after hydrate decomposition will affect the strength of the hydrate memory *** simulation results provide microscopic insights into the occurrence of the hydrate memory effect and shed light on the hydrate reformation process at the molecular scale.

关键词： Memory effect Molecular simulation Hydrate reformation Residual structures

Elaborative collection of condensed combustion products of solid propellants:Towards a real Solid Rocket Motor(SRM)operational environment

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Chinese Journal of Aeronautics 2024年第1期37卷 77-88页

作者： Wenchao ZHANG Zhimin FAN Dongliang GOU Yao SHU Peijin liu Aimin PANG Wen AO National Key Laboratory of Solid Rocket Propulsion Northwestern Polytechnical UniversityXi’an 710072China Science and Technology on Aerospace Chemical Power Laboratory Xiangyang 441003China

A novel constant-pressure and constant-quenching distance Condensed Combustion Products(CCPs)collection system was developed,coupled with a timing control system,to collect the CCPs formed in the course of burning of aluminum-based composite *** effects of adiabatic graphite plating,collection zone,quenching distance,time series of collection,and propellant burning rate on the microscopic morphology,particle size distribution and unburned aluminum content of CCPs were *** was verified that the graphite plating can provide a high-fidelity high-temperature environment for propellant *** combustion efficiency is improved by 2.44% compared to the bare propellant *** time series of collection has a significant effect on the combustion efficiency of aluminum,and the combustion efficiency of aluminum in the thermal state(1.2-2.4 s)is 2.75% higher than that in the cold state(0-1.2 s).Similarly,the characteristics of the CCPs in different collection zones are *** the quenching distance of 5 mm,the combustion efficiency of aluminum in the core zone(85.39%)is much lower than that in the outer zone(92.07%),while the particle size of the CCPs in the core zone(172μm)is larger than that in the outer zone(41μm).This indicates that the core zone is more likely to produce large-sized and incompletely burned agglomerates during the propellant combustion *** burning rates also lead to a significant difference in particle size distribution and combustion *** burning rates result in higher combustion efficiency.A detailed sequence of the elaborative collection process of CCPs is proposed,mainly including the setting of ignition delay time,burning rate,working pressure,plating length and time series of *** findings of this study are expected to provide a reliable tool for the evaluation of the combustion efficiency of solid propellants.

关键词： Composite propellants Condensed combustion products Aluminum Combustion efficiency Particle size distribution

Pt nanoclusters modified porous g-C_(3)N_(4)nanosheets to significantly enhance hydrogen production by photocatalytic water reforming of methanol

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Chinese Journal of Chemical Engineering 2024年第2期66卷 40-50页

作者： Yi-Fei Liang Jin-Rong Lu Shang-Kun Tian Wen-Quan Cui Li liu hebei Provincial Key Laboratory of Environmental Photocatalytic and Electrocatalytic Materials College of Chemical EngineeringNorth China University of Science and TechnologyTangshan 063210China

For the use of green hydrogen energy,it is crucial to have efficient photocatalytic activity for hydrogen generation by water reforming of methanol under mild *** attention has been paid to gC_(3)N_(4)as a promising photocatalyst for the generation of *** improve the separation of photogenerated charge,porous nanosheet g-C_(3)N_(4)was modified with Pt nanoclusters(Pt/g-C_(3)N_(4))through impregnation and following photo-induced *** catalyst showed excellent photocatalytic activity of water reforming of methanol fo r hydrogen production with a 17.12 mmol·g^(-1)·h^(-1)rate at room temperature,which was 311 times higher than that of the unmodified g-C_(3)N_(4).The strong interactions of Pt-N in Pt/g-C_(3)N_(4)constructed effective electron transfer channels to promote the separation of photogenerated electrons and holes *** addition,in-situ infrared spectroscopy was used to investigate the intermediates of the hydrogen production reaction,which proved that methanol and water eventually turn into H_(2)and CO_(2)via formaldehyde and *** study provides insights for understanding the photocatalytic hydrogen production in the water reforming of methanol.

关键词： Water reforming of methanol Photocatalysis g-C_(3)N_(4) Pt nanoclusters Hydrogen production

Visualization of MF/Diesel RCCI Combustion Process and Soot Emission

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Journal of Thermal Science 2024年第2期33卷 779-792页

作者： HUANG Chen NI Xiao GE Dameng LI Song ZHANG Wanzhi liu Jinping ZHANG Tingting School of Mechanical and Electronic Engineering Shandong Agricultural UniversityTaian271018China Shandong Provincial Engineering Laboratory of Agricultural Equipment Intelligence Taian271018China Taian Technician Institute Taian271000China Sinotruk Taian Wuyue Special Vehicle Co. Ltd.Taian271000China School of Mechanical Engineering Shaanxi University of TechnologyHanzhong723001China School of Mechanical Engineering Anyang Institute of TechnologyAnyang455000China

Based on the optical engine,the ignition characteristics,combustion process and soot emission characteristics of diesel under different 2-Methylfuran(MF) atmospheres were investigated by high-speed photography and in-cylinder combustion analysis *** results show that at the same main injection timing,the ignition time of reactivity controlled compression ignition(RCCI) combustion mode is earlier than pure diesel combustion,and the ignition point is concentrated near the *** acts as a spark plug to ignite the mixture,but the flame develops slowly in the early stages and the pressure in the cylinder rises *** with pure diesel,RCCI combustion model has smaller peak values of in-cylinder pressure and heat release rate,shorter ignition delay period,earlier combustion phase and shorter combustion *** main spray time at 6℃A BTDC and 12℃A BTDC,with the increase of MF premixing ratio from 0 to 0.75,the peak cylinder pressure decreased by 19.6% and 26% *** addition,with the increase of the MF heat value ratio,the area of KL factor> 1.5 in the combustion chamber decreased and the space integral natural luminescence(SINL) peak value decreased by 48.37%,and the soot formation rate and yield decreased ***,when the MF heat value ratio was too large(75% of the total calorific value),the ignition delay period increased,and misfire occurred at the main injection timing of 0℃A *** RCCI mode of MF/diesel dual fuel has better stability,and better control effect can be obtained at different main inj ection timing.

关键词： 2-methylfuran RCCI visualization two-color method KL factor

Seismic fragility analysis of three-tower cable-stayed bridges with different connection configurations

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Earthquake Engineering and Engineering Vibration 2024年第4期23卷 1009-1027页

作者： Chen Chen liu Jinlong Lin Junqi Li Suchao Key Laboratory of Earthquake Engineering and Engineering Vibration Institute of Engineering MechanicsChina Earthquake AdministrationHarbin 150080China Key Laboratory of Earthquake Disaster Mitigation Ministry of Emergency ManagementHarbin 150080China Key Laboratory of Structural Dynamic Behavior and Control Ministry of EducationHarbin Institute of TechnologyHarbin 150090China

Seismic fragility analysis of three-tower cable-stayed bridges with three different structural systems,including rigid system(RS),floating system(FS),and passive energy dissipation system(PEDS),is conducted to study the effects of connection configurations on seismic responses and *** element models of bridges are established using OpenSees.A new ground motion screening method based on the statistical characteristic of the predominant period is proposed to avoid irregular behavior in the selection process of ground motions,and incremental dynamic analysis(IDA)is performed to develop components and systems fragility *** effects of damper failure on calculated results for PEDS are examined in terms of seismic response and fragility *** results show that the bridge tower is the most affected component by different structural *** RS,the fragility of the middle tower is significantly higher than other components,and the bridge failure starts from the middle tower,exhibiting a characteristic of local *** FS and PEDS,the fragility of the edge tower is higher than the middle *** system fragility of RS is higher than FS and *** the failure of dampers into account is necessary to obtain reliable seismic capacity of cable-stayed bridges.

关键词： seismic fragility cable-stayed bridge connection configuration viscous damper comparison analysis

Dynamic thermo-mechanical responses of road-soft ground system under vehicle load and daily temperature variation

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第5期16卷 1722-1731页

作者： Chuxuan Tang Jie liu Zheng Lu Yang Zhao Jing Zhang Yinuo Feng State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China University of Chinese Academy of Sciences Beijing100049China Xinjiang Transportation Planning Survey and Design Institute Co. Ltd.Urumqi830006China Hubei Key Laboratory of Geo-Environmental Engineering Wuhan430071China

A complete road-soft ground model is established in this paper to study the dynamic responses caused by vehicle loads and/or daily temperature variation.A dynamic thermo-elastic model is applied to capturing the behavior of the rigid pavement,the base course,and the subgrade,while the soft ground is characterized using a dynamic thermo-poroelastic *** to the road-soft ground system are derived in the Laplace-Hankel transform *** time domain solutions are obtained using an integration *** temperature,thermal stress,pore water pressure,and displacement responses caused by the vehicle load and the daily temperature variation are *** show that obvious temperature change mainly exists within 0.3 m of the road when subjected to the daily temperature variation,whereas the stress responses can still be found in deeper places because of the thermal swelling/shrinkage deformation within the upper road ***,it is important to consider the coupling effects of the vehicle load and the daily temperature variation when calculating the dynamic responses inside the road-soft ground system.

关键词： Dynamic response Vehicle load Daily temperature variation Thermo-poroelastic medium Coupling effects