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Comparisons of Wave Force Model Effects on the Structural Responses and Fatigue Loads of a Semi-Submersible Floating Wind Turbine

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Journal of Ocean University of China 2024年第1期23卷 69-79页

作者： HAN Yanqing le Conghuan ZHANG Puyang XU Shengnan State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin UniversityTianjin 300072China School of Hydraulic Engineering Ludong UniversityYantai 264025China School of Civil Engineering Tianjin UniversityTianjin 300072China Shandong Marine Aerospace Equipment Technological Innovation Center Yantai 264004China

The selection of wave force models will significantly impact the structural responses of floating wind *** this study,comparisons of wave force model effects on the structural responses and fatigue loads of a semi-submersible floating wind turbine(SFWT)were *** were performed by employing the Morison equation(ME)with linear or second-order wave kinematics and potential flow theory(PFT)with first-or second-order wave forces.A comparison of regular waves,irregular waves,and coupled wind/waves analyses with the experimental data showed that many of the simulation results and experimental data are relatively ***,notable discrepancies are found in the response amplitude operators for platform heave,tower base bending moment,and tension in mooring *** models give more satisfactory results of heave but more significant discrepan-cies in tower base bending moment than the ME *** irregular wave analyses,low-frequency resonances were captured by PFT models with second-order difference-frequency terms,and high-frequency resonances were captured by the ME models or PFT models with second-order sum-frequency *** force models capture the response frequencies but do not reasonably predict the response *** coupled wind/waves analyses showed more satisfactory results than the wave-only ***,an important detail to note is that this satisfactory result is based on the overprediction of wind-induced responses.

关键词： floating wind turbine wave force model potential flow theory Morison equation second-order wave forces

Theoretical study of the nonlinear force-loading control in single-molecule stretching experiments

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Communications in Theoretical Physics 2024年第4期76卷 167-175页

作者： Xingyu Qi Zilong Guo Shimin le Hu Chen Research Institute for Biomimetics and Soft Matter Fujian Provincial Key Lab for Soft Functional Materials ResearchDepartment of PhysicsXiamen UniversityXiamen 361005China Center of Biomedical Physics Wenzhou InstituteUniversity of Chinese Academy of SciencesWenzhou 325000China

Force spectrum measurements with constant loading rates are widely used in single-molecule manipulation experiments to study the mechanical stability and force response of ***-dependent transition rates can be obtained from the transition force distribution,but it is limited to the force range with non-zero force *** constant loading rate control can be realized with magnetic tweezers,the loading rate range is limited due to the slow movement of permanent ***-linear exponential and exponential squared force loading functions are more feasible in magnetic tweezers,while there is no theoretical result available for these two kinds of non-linear force loading *** this study,we solved the unfolding process of a protein following Bell's model under nonlinear exponential and exponential squared force loading functions,which offer a broader range of unfolding force distribution compared to the traditional constant loading rate ***,we derived two force loading functions,which can produce uniform unfolding force *** research contributes fundamental equations for the analysis of experimental data obtained through single-molecule manipulation under nonlinear force loading controls,paving the way for the use of nonlinear force control in magnetic tweezer experiments.

关键词： single-molecule manipulation magnetic tweezers force loading transition rates force distribution

Process intensification for the synthesis and purification of battery-grade Li_(2)CO_(3)with microfluidics

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Particuology 2024年第7期90卷 106-117页

作者： Haodu Li Jie Zhang Lin dai le du Jiqin Zhu The State Key Laboratory of Chemical Resource Engineering College of Chemical EngineeringBeijing University of Chemical TechnologyBeijing 100029China

Battery-grade lithium carbonate(Li_(2)CO_(3))with a purity of higher than 99.5 wt%is of great importance as a high value-added lithium ***,influences of different reaction systems and process control on product purity remain ***,a membrane dispersion microreactor was used to enhance the mass transfer of preparation and purification processes in homogeneous and heterogeneous *** systems of Na_(2)CO_(3)–LiCl,NH_(4)HCO_(3)–LiCl,and NH_(3)·H_(2)O−CO_(2)−LiCl,CO_(2)purification based on carbonation and decomposition were *** Li_(2)CO_(3)purity was increased by the improvement of mixing *** carbonation time was reduced by 62.5%and 58.3%for the NH_(3)·H_(2)O−CO_(2)and CO_(2)purification systems,*** the two ammonia-based systems,Li_(2)CO_(3)particles with a purity of 99.7–99.8 wt%were one-step prepared with a size of 3–5μm,which also met the requirement of the battery-grade *** purity was further increased to 99.9 wt%by CO_(2)purification and LiHCO_(3)*** investigation could provide a feasible alternative for the controllable preparation of battery-grade Li_(2)CO_(3)in one or multiple steps.

关键词： Microfluidics Battery grade Li_(2)CO_(3) Process intensification High purity

disturbances rejection optimization based on improved two-degree-of-freedom LAdRC for permanent magnet synchronous motor systems

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defence Technology（防务技术） 2024年第3期33卷 518-531页

作者： Chenggang Wang Jianhu Yan Wenlong Li Liang Shan le Sun School of Automation Nanjing University of Science and TechnologyNanjing 210094China

Permanent magnet synchronous motor(PMSM)speed control systems with conventional linear active disturbance rejection control(CLAdRC)strategy encounter issues regarding the coupling between dynamic response and disturbance suppression and have poor performance in suppressing complex nonlinear *** order to address these issues,this paper proposes an improved two-degree-of-freedom LAdRC(TdOF-LAdRC)strategy,which can enhance the disturbance rejection performance of the system while decoupling entirely the system's dynamic and anti-disturbance performance to boost the system robustness and simplify controller parameter *** models that consider total disturbances are developed to design the TdOF-LAdRC speed controller ***,to evaluate the control performance of the TdOF-LAdRC strategy,its stability is proven,and the influence of each controller parameter on the system control performance is *** on it,a comparison is made between the disturbance observation ability and anti-disturbance performance of TdOF-LAdRC and CLAdRC to prove the superiority of TdOF-LAdRC in rejecting ***,experiments are performed on a 750 W PMSM experimental platform,and the results demonstrate that the proposed TdOF-LAdRC exhibits the properties of two degrees of freedom and improves the disturbance rejection performance of the PMSM system.

关键词： Permanent magnet synchronous motor(PMSM) Active disturbance rejection control(AdRC) disturbance observer Two-degree-of-freedom control Anti-disturbance

A rare case of hepatic vein-portal vein fistula with hepatolithiasis presenting as cholangiocarcinoma

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Hepatobiliary & Pancreatic diseases International 2024年第5期23卷 538-540页

作者： Wei Li Wen Lin le Xiao General Surgery Center The General Hospital of Western Theater CommandChengdu 610083China

To the Editor: We sincerely applaud the work by Tang et al., in which they described caudate lobe-sparing subtotal hepatectomy as treatment for intrahepatic arterioportal fistulas [ 1 ]. Compared to intrahepatic arterioportal fistulas, portal vein-hepatic vein fistulas are rarely reported. Patients typically lack clinical symptoms such as hyperammonemia, cholestatic jaundice, and hypoglycemia, unless the shunt becomes relatively large [ 2, 3 ]. Herein, we describe partial hepatectomy as a treatment for cases of left portal vein-mid.le hepatic vein fistulas.

关键词： hepatic clinical

Mineralogical properties and co-sintering characteristics of fluxed iron ore with magnetite concentrates

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Journal of Iron and Steel Research International 2024年第2期31卷 318-328页

作者： le-le Niu Zheng-jian Liu Jian-liang Zhang Yao-zu Wang Zhen-xing Yang Si-da Li Chang-dong Shan Ben Feng School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing100083China Institute of Artificial Intelligence University of Science and Technology BeijingBeijing100083China Xinxing Casting Pipe Xinjiang Co. Bayingol841300XinjiangChina

To investigate the feasibility of co-sintering of fluxed iron ore with magnetite concentrates, the mineralogical properties of a novel fluxed iron ore were studied using particle size analysis, microscopic morphology characterization, and X-ray diffraction Rietveld analysis. Following that, the experiments for granulation performance and basic sintering characteristics were designed under seven different fluxed iron ore ratios, and the integrated ranking of different fluxed iron ore ratios was determined using gray relation analysis. Finally, the results of the industrial trails were combined with the feasibility analysis. Test and experimental results show that the fraction of the fluxed iron ore particles larger than 0.5 mm can account for more than 48%, and the particles have two morphologies: spherical-rough and flaky-smooth. Ca elements are found in the form of calcite (CaCO3) and dolomite (CaMg(CO3)2). The average particle size of granules and powder removal rate can be improved from 2.50 to 3.16 mm and 39.60% to 24.20%, respectively, with the increase in the fluxed iron ore ratio. Furthermore, the fluxed iron ore can improve assimilability and liquid fluidity of magnetite concentrates. In terms of overall granulation performance and sintering characteristics, the fluxed iron ore ratios are graded from best to worst as follows: 12%, 15%, 9%, 18%, 21%, 6% and 3%. The industrial trails show that when the fluxed iron ore ratio is increased, the beneficial effect of the superior sintering characteristics of the fluxed iron ore itself is ideally balanced with the negative effect of the lower amount of additional CaO at 12% ratio, and thus, it is feasible to bring the fluxed iron ore into production at a level of roughly 12%.

关键词： Fluxed iron ore Magnetite concentrate Granulation performance Sintering characteristics Gray relation analysis

Understanding the Activity Performance of Comets 38P/Stephan-Oterma,64P/Swift-Gehrels and C/2017 M4(ATLAS)through Broadband Photometric Observations

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Research in Astronomy and Astrophysics 2024年第8期24卷 147-156页

作者： Xuan Zhang Jin-Zhong Liu le-Tian Wang Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China

In this work,we report observations of three comets:38P/Stephan-Oterma,64P/Swift-Gehrels,and C/2017 M4(ATLAS),conducted with the Nanshan one-meter wide-field telescope in 2018 August and November,and *** extracted morphological features through image enhancement techniques and calculated the dust activity parameter,Afρ,along with dust mass loss rates and coma color indices using broadband photometric *** morphological analysis uncovered a spectrum of dust characteristics among the observed comets,ranging from a significant twisted structure in comet 38P/Stephan-Oterma’s coma to the regular coma envelope surrounding comet 64P/*** Afρvalues varied between 148.8±0.3 cm for 64P/Swift-Gehrels and1118.5±6.2 cm for C/2017 M4(ATLAS)(measured within a reference aperture radius ofρ=6″),indicating a range from moderate to high activity *** mass loss rates were estimated from 328.1 kg s^(-1)for comet 64P/Swift-Gehrels to 1395.5 kg s^(-1)for comet C/2017 M4(ATLAS).The color indices of comets 38P/Stephan-Oterma and C/2017 M4(ATLAS)closely resemble the average colors of active short-period comets and active longperiod comets,*** contrast,64P/Swift-Gehrels exhibits a significantly bluer hue than typical Jupiter family comets.

关键词： comets general-comets individual(38P/Stephan-Oterma,64P/Swift-Gehrels,C/2017 M4(ATLAS))-techniques photometric

leader-follower Optimal Selection Method for distributed Control System in Active distribution Networks

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CSEE Journal of Power and Energy Systems 2024年第1期10卷 314-323页

作者： Jian le Liangang Zhao Cao Wang Qian Zhou Yang Wang School of Electrical Engineering and Automation Wuhan UniversityWuhan 430072China

Aiming at the shortcomings of a traditional centralized control in an active distribution network(ANd),this paper proposes a leader-follower distributed group cooperative control strategy to realize multiple operation and control tasks for an *** distributed information exchange protocols of the distributed generation(dG)group devoted to node voltage regulation or exchange power control are developed using a dG power utilization ratio as the consensus *** these bases,this study further investigates the leader optimal selection method for a dG group to improve the response speed of the distributed control ***,a single or multiple leader selection model is established to minimize the constraints of the one-step convergence factor and the number of leaders to improve the response speed of the distributed control *** simulation results of the IEEE 33 bus standard test system show the effectiveness of the proposed distributed control *** addition,the response speed of a dG control group can be improved effectively when the single or multiple leaders are selected optimally.

关键词： Active distribution1network consensus algorithm leader-follower system mixed-integer semidefinite programming optimal distributed control

Exponentially Bounded C-semigroup and the Cauchy Initial Value Problems in Complete Random Normed Mod.les

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Acta Mathematica Sinica,English Series 2024年第9期40卷 2195-2212页

作者： Son TA CONG Thang dang HUNG Oanh le THI department of Mathematics University of ScienceVietnam National University 334 Nguyen TraiThanh XuanHanoiVietnam Faculty of Natural Sciences Hong Duc University565 Quang TrungDong VeThanh HoaVietnam

In this paper,the notion of C-semigroup of continuous mod.le homomorphisms on a complete random normal(RN)mod.le is introduced and *** existence and uniqueness of solution to the Cauchy problem with respect to exponen... 详细信息

关键词： C-semigroup Cauchy problem random normed mod.les L^(0)-Lipschitz