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Estimation of secondary nucleation kinetics of benzoic acid in batch crystallizer

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Particuology 2024年第4期87卷 232-239页

作者： Yan Zhao Weiyuan Zhang Jinbo Ouyang Guangyang Hou Vamsi Krishna Kamaraju Brian Glennon School of Chemical Engineering Hebei Normal University of Science and TechnologyQinhuangdao066004China Synthesis and Solid State Pharmaceutical Centre School of Chemical and Bioprocess EngineeringUniversity College DublinDublin 4Ireland jiangxi province key laboratory of Polymer Micro/Nano Manufacturing and Devices East China University of TechnologyNanchang330013China APC Ltd Dublin 4Ireland

The nucleation and growth kinetics of benzoic acid were determined in a population balance model,describing the seeded batch antisolvent crystallization *** process analytical technologies(PATs)were utilized to record the evolution of chord length distributions(CLDs)in solid phase together with the concentration decay in liquid phase,which provided essential experimental information for parameter *** model was solved using standard method of moments based on the moments calculated from CLDs and solute concentration.A developed model,incorporating the nucleation and crystal growth as functions of both supersaturation and solvent composition,has been constructed by fitting the zeroth moment of particles and concentration *** determined kinetic parameters were consequently validated against a new experiment with a different flow rate,indicating that the developed model predicted crystallization process reasonably *** work illustrates the strategy in construct a population balance model for further simulation,model-based optimization and control studies of benzoic acid in antisolvent crystallization.

关键词： Benzoic acid Antisolvent crystallization Population balance equation Nucleation Growth

Impacts of major volcanic eruptions over the past two millennia on both global and Chinese climates:A review

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Science China Earth Sciences 2024年第1期67卷 61-78页

作者： Weiyi SUN Deliang CHEN Guonian LÜ Liang NING Chaochao GAO Renhe ZHANG Bin WANG Jian LIU key laboratory for Virtual Geographic Environment Ministry of EducationState Key Laboratory Cultivation Base of Geographical Environment Evolution of Jiangsu ProvinceJiangsu Center for Collaborative Innovation in Geographical Information Resource Development and ApplicationSchool of Geography ScienceNanjing Normal UniversityNanjing 210023China Regional Climate Group Department of Earth SciencesUniversity of GothenburgGothenburg 40530Sweden College of Environmental and Resource Science Zhejiang UniversityHangzhou 310058China Department of Atmospheric and Oceanic Sciences&Institute of Atmospheric Sciences Fudan UniversityShanghai 200437China Department of Atmospheric Sciences and Atmosphere-Ocean Research Center University of Hawaii at ManoaHonoluluHI 96825USA Jiangsu Provincial key laboratory for numerical simulation of Large Scale Complex Systems School of Mathematical ScienceNanjing Normal UniversityNanjing 210023China Open Studio for the simulation of Ocean-Climate-Isotope Qingdao National Laboratory for Marine Science and TechnologyQingdao 266237China

Major volcanic eruptions(MVEs)have attracted increasing attention from the scientific *** studies have explored the climatic impact of MVEs over the past two ***,proxy-based reconstructions and climate model simulations indicate divergent responses of global and China’s regional climates to ***,we used multiple data from observations,reconstructions,simulations,and assimilations to summarize the historical facts of MVEs,the characteristics and mechanisms of their climatic impact,and directions for future *** reviewed volcanic datasets and determined intensive MVE periods;these periods corresponded to the years 530–700,1200‒1460,and 1600‒1840 *** tropical MVEs,a substantial cooling effect is observed throughout the globe and China on the interannual-interdecadal time scales but an inconsistent cooling magnitude is detected between reconstructions and *** the first summer after tropical MVEs,a decrease in global and monsoonal precipitation is *** reconstructions and simulations,an increased precipitation is seen for the Yangtze River Basin,while large uncertainties in precipitation changes are present for other regions of *** drought can be induced by frequent eruptions and volcanism superimposed on low solar irradiation and internal *** affect climate directly through the radiative effect and indirectly by modulating internal variability,such as the El Niño‒Southern Oscillation(ENSO)and Atlantic Multidecadal Oscillation(AMO).However,changes in the phase,amplitude,and periodicity of ENSO and AMO after MVEs and the associated mechanisms remain controversial,which could account for model-reconstruction ***,other internal variability,uncertainties in reconstruction methods and aerosol‒climate models,and climate background may also induce model-reconstruction *** gaps and directions for future research are also discussed.

关键词： Major volcanic eruption Climate variability Mechanism Past two millennia Internal variability

Multiple model PHD filter for tracking sharply maneuvering targets using recursive RANSAC based adaptive birth estimation

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Journal of Systems Engineering and Electronics 2024年第3期35卷 780-792页

作者： DING Changwen ZHOU Di ZOU Xinguang DU Runle LIU Jiaqi School of Astronautics Harbin Institute of TechnologyHarbin 150001China School of Electronics and Information Engineering Harbin Institute of TechnologyHarbin 150001China National key laboratory of Science and technology on Test Physics and numerical Mathematics Beijing 100076China

An algorithm to track multiple sharply maneuvering targets without prior knowledge about new target birth is proposed. These targets are capable of achieving sharp maneuvers within a short period of time, such as drones and agile *** probability hypothesis density (PHD) filter, which propagates only the first-order statistical moment of the full target posterior, has been shown to be a computationally efficient solution to multitarget tracking problems. However, the standard PHD filter operates on the single dynamic model and requires prior information about target birth distribution, which leads to many limitations in terms of practical applications. In this paper,we introduce a nonzero mean, white noise turn rate dynamic model and generalize jump Markov systems to multitarget case to accommodate sharply maneuvering dynamics. Moreover, to adaptively estimate newborn targets’information, a measurement-driven method based on the recursive random sampling consensus (RANSAC) algorithm is proposed. simulation results demonstrate that the proposed method achieves significant improvement in tracking multiple sharply maneuvering targets with adaptive birth estimation.

关键词： multitarget tracking probability hypothesis density(PHD)filter sharply maneuvering targets multiple model adaptive birth intensity estimation

Advancing electrochemical drilling process via coupling of flow field and electric field in pulsating state generated by a novel tube tool

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Chinese Journal of Aeronautics 2024年第4期37卷 542-555页

作者： Liang CHENG Xiaolei CHEN Zhisen YE Yongjun ZHANG State key laboratory of Precision Electronic Manufacturing technology and Equipment Guangdong University of TechnologyGuangzhou 510006China Guangdong key laboratory of Advanced Manufacturing technology of Marine Energy Equipment Guangdong University of TechnologyGuangzhou 510006China Guangzhou key laboratory of Nontraditional Machining and Equipment Guangdong University of TechnologyGuangzhou 510006China

This paper introduces an improvement to electrochemical drilling process by coupling flow field and electric field in pulsating state. A novel tube with half-wedged shape at the end(HW-tube) is prepared, with both sidewall and wedged part of the HW-tube insulated. Only the flat part is utilized to provide electric field for electrochemical drilling. By rotating the HW-tube, both flow field and electric field in pulsating state are generated, alternating in different positions within the inter-electrode gap(IEG). The pulsating flow field enhances the mass transfer process, while pulsating electric field disperses material dissolution process and distribution of electrolytic byproducts. Both pulsating fields are coupled at the same frequency, further enhancing the electrochemical drilling process. simulation results indicate that both flow field and electric field in pulsating state are generated. Compared to the traditional tube, the HW-tube significantly reduces the number of residual particles in IEG, and this number is further reduced by increasing the rotation speed. Experimental results reveal that the surface quality and dimensional uniformity of small hole are improved with HW-tube. With feed rate of 2.22 mm/min, a small hole with diameter of 1.52± 0.017 mm is drilled, resulting in a surface roughness of 0.331 μm.

关键词： Small holes Electrochemical drilling Tools Pulsating flow field Pulsating electric field

numerical simulation of Radial Ultrasonic Assisted MIG Welding Arc

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Journal of Shanghai Jiaotong university(Science) 2024年第2期29卷 330-338页

作者：洪蕾肖皓叶佳马国红 key laboratory of Lightweight and High Strength Structural Materials of jiangxi province School of Mechanical EngineeringNanchang UniversityNanchang 330031China Applied Materials Inc.Santa ClaraCA 95054-3299USA

The numerical simulation of arc was carried out for both conventional melt inert gas(MIG)welding and ultrasonic assisted melt inert gas(U-MIG)*** on the model established by Fluent,the arc shape,temperature field,and potential distribution were *** study found that the shape of the arc changed when ultrasonic was added radially;the high-temperature area of the arc stretched,and the temperature peak *** as the current increased,the increase in temperature *** addition,under the same conditions,the potential of U-MIG decreased and the pressure on the workpiece *** verify the accuracy of the simulation results,welding experiments under identical conditions were carried out,and a high-speed camera was used to collect dynamic pictures of the *** simulation results were in a favorable agreement with the experimental results,which provided a certain reference value for ultrasonic assisted arc welding.

关键词： numerical simulation welding arc ultrasonic arc welding arc temperature

Nanopore design of sulfur doped hollow carbon nanospheres for superior potassium-ion battery anodes

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Rare Metals 2024年第5期43卷 2103-2114页

作者： Zhen-Dong Liu Hui-Yan Feng Yu-Chen Wang Fei Wang Yue Liu Jian-Xiao Yang Yue Gu Jun Tan Chong Ye Cheng-Zhi Zhang Ji Hua laboratory Foshan 528000China School of Chemical Engineering and Light Industry Guangdong University of TechnologyGuangzhou 510006China Hunan province key laboratory for Advanced Carbon Materials and Applied technology College of Materials Science and EngineeringHunan UniversityChangsha 410082China

Sulfur doped carbonaceous materials are promising anodes for potassium-ion batteries because of their ability to bridge active sites and induce C/S electron coupling,resulting in increased ion storage capacitance However,the large potassium ions could cause significant volume expansion and structure collapse during operation in sulfur doped carbonaceous anodes,which lead to rapidly capacity sacrifice during long-term *** design for anchoring sulfur atom in carbon skeleton is a novel way to alleviate the structure collapse and maintain the cycling ***,this study developed a controlled nanopore and sulfur doped carbon sphere structure(S-NPHCSs).In potassium-ion batteries S-NPHCSs anode demonstrated exceptional performance with a high reversible capacity of 247 mAh·g^(–1)after 50 cycles at 0.2 A·g^(–1)and delivered a long cycle stability of 600 cycles at a high current density of 1.0 A·g^(–1).Interconnected nanopores and doped sulfur structure not only expand the accumulation space and offer ample active sites for diffusion and adsorption of potassium ions,but also build stable channels through nanopore structure to ensure the cyclic *** finding provides a fundamental theory for designing nanopore structures and introducing sulfur doped carbonaceous materials to enhance capacitive potassium storage and long cycle stability.

关键词： Nanopore Carbon materials Sulfur doping Anode Potassium-ionbatteries

Organic interfacial engineering of gold nanowires for selective glycerol electrooxidation

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Chinese Chemical Letters 2024年第3期35卷 502-507页

作者： Zhe Wang Qingling Hong Boqiang Miao Tianjiao Wang Yu Ding Pujun Jin Pei Chen Yu Chen key laboratory of Macromolecular Science of Shaanxi province Key Laboratory of Applied Surface and Colloid Chemistry(Ministry of Education)Shaanxi Key Laboratory for Advanced Energy DevicesSchool of Materials Science and EngineeringShaanxi Normal UniversityXi'an 710062China

The selective electrochemical conversion of glycerol into value-added products is a green and sustainable strategy for the biomass *** this work,Au nanowires(Au-NW)modified with polyethyleneimine(PEI)molecule(Au-NW@PEI)is obtained by an up-bottom post-modification *** characterization,molecular dynamics simulation and density functional theory demonstrate that the loose-packed PEI monolayer firmly and uniformly distribute on the Au-NW surface due to the strong Au-N *** experiments and product analysis display that PEI modification significantly enhance the electro-activity of Au-NW for the glycerol electro-oxidation reaction(GEOR)due to the electronic ***,the steric hindrance and electrostatic effect of PEI layer make the optimizing adsorption of intermediates ***,the selectivity of C3 product glyceric acid over Au-NW@PEI is increased by nearly 20%.The work thus indicates that the rational design of metal-organic interface can effectively elevate the electro-activity and selectivity of Au nanostructures,which may have wide application in biomass development.

关键词： Glycerol electrooxidation reaction Organic interface engineering Gold-based nanomaterials Electrocatalysis Selectivity

numerical simulation of granular silicon growth and silicon fines formation process in polysilicon fluidized bed

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Particuology 2024年第4期87卷 74-86页

作者： Guangkai Gu Guoqiang Lv Wenhui Ma Shanlin Du Boqiang Fu Faculty of Metallurgical and Energy Engineering Kunming University of Science and TechnologyKunming 650093China State key laboratory of Complex Nonferrous Metal Resources Cleaning Utilization in Yunnan province Kunming 650093China

Operating conditions strongly affect the yield and quality of polysilicon in a polysilicon fluidized *** this study,a new model of polysilicon fluidized bed was established using the Euler-Euler model coupled with population balance model(PBM),which was combined with fluid flow,heat,and mass transfer models,while considering the scavenging effect of silicon *** effects of different operating conditions on the deposition and formation rates of silicon fines were *** show that the model can correctly describe the particle growth process in the fluidized bed of *** silicon fines and the interphase velocity difference show"N"-and"M"-shaped distributions along the axial direction,*** particle temperature and concentration near the wall are higher than those in the central *** decomposition of silane in the bottom region of the bed is dominated by het-erogeneous *** scavenging of silicon fines occurs in the dilute-phase *** effects of operating conditions,*** gas temperature,silane composition,and gas velocity,on the reactor performance were also explored *** the inlet gas composition and velocity enhances the formation rates of solid silicon and *** the inlet gas temperature promotes the growth of solid silicon and inhibits the formation of silicon *** fluidization ratio,low inlet silane concentration,and high inlet gas temperature enhance the selectivity of silicon growth.

关键词： Polysilicon fluidized bed Particle growth Fines CFD Population balance model(PBM)

Impedance Model for Instability Analysis of LCC-HVDCs Considering Transformer Saturation

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Journal of Modern Power Systems and Clean Energy 2024年第4期12卷 1309-1319页

作者： Qin Jiang Ruiting Xu Baohong Li Xiang Chen Yue Yin Tianqi Liu Frede Blaabjerg College of Electrical Engineering Sichuan UniversityChengdu 610065China Smart Grid key laboratory of Sichuan province Chengdu 610065China Department of Energy technology Aalborg UniversityAalborg 9920Denmark

In line commutated converter based high-voltage direct current(LCC-HVDC)transmission systems,the trans-former saturation can induce harmonic instability,which poses a serious threat to the safe operation of the power ***-ever,the nonlinear characteristics of the power grids introduced by the transformer saturation considerably limit the application of the conventional analysis *** address the issue,this paper derives a linear model for the transformer saturation caused by the DC current due to the converter ***-terwards,the nonlinear characteristics of power grids with the transformer saturation is described by a complex valued imped-ance *** on the derived impedance matrix,the sys-tem harmonic stability is analyzed and the mechanism of the transformer saturation induced harmonic instability is ***,the sensitivity analysis is conducted to find the key fac-tors that influence the system core saturation *** proposed impedance model is verified by the electromagnetic transient simulation,and the simulation results corroborate the effectiveness of the proposed impedance *** TermsLine commutated converter based high voltage direct current(LCC-HVDC),transformer saturation,harmonic instability,impedance model.

关键词： Line commutated converter based high voltage direct current(LCC-HVDC) transformer saturation harmonic instability impedance model