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VIBRATION RESPONSE AND ITS CHARACTERISTICS OF CENTRIFUGAL COMPRESSOR WITH ROTATING STALL 被引量:2
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作者 YanXianguo GuanHuiling ZhangYouyun 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2004年第1期136-141,共6页
Based on the beginning, propagating and ending mechanism of rotating-stallcell, the relation between the pressure history signal and the pressure distribution along rotorcircumference is proposed. The angular velociti... Based on the beginning, propagating and ending mechanism of rotating-stallcell, the relation between the pressure history signal and the pressure distribution along rotorcircumference is proposed. The angular velocities of rotating-stall cell propagating are computedfrom time series picked by the pressure probes on a cross section. Self-relation calculatingfiltered the random noise of the pressure history data. The exciting load on rotor is computed byintegral of filtered pressure signal along rotor circumference. By Prohl-Myklestad method, dynamicalequations of rotor system are obtained. The dynamical response of rotor system is resolved by usingMatlab system. Further more, the situation of more than one of stall cells is discussed. Two casesrespectively from the natural gas compressor of some fertilizer plant and the CO_2 compressor ofsome nitrogenous fertilizer plant demonstrate that both methods of calculating the load exerted onrotor by pressure fluctuation and resolving the dynamic response of rotor are available and thecharacteristics of frequency spectrum of rotating stall are correct. 展开更多
关键词 rotating stall Exciting from rotating-stall Characteristics of rotatingstall Symptom of rotating stall Self-relation analysis filter
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Numerical investigation of mixing enhancement mechanism and propagation characteristics of rotating detonation waves in a ramjet-based engine
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作者 Yuting CHEN Shijie LIU +3 位作者 Haoyang PENG Si LIU Weijie FAN Weidong LIU 《Chinese Journal of Aeronautics》 2025年第11期68-80,共13页
This study investigates the mixing enhancement mechanism and propagation characteristics of the detonation flow field of a Rotating Detonation Engine(RDE).Three-dimensional numerical simulations of a non-premixed ramj... This study investigates the mixing enhancement mechanism and propagation characteristics of the detonation flow field of a Rotating Detonation Engine(RDE).Three-dimensional numerical simulations of a non-premixed ramjet-based RDE fueled by gaseous ethylene are performed in OpenFOAM for configurations with 15,30,45,and 60 orifices at a flight Mach number of 4.The results show that fuels with a stripped distribution are primarily mixed via tangential diffusion in the cold flow field.The configuration with more orifices has a better upstream mixing efficiency,whereas its downstream mixing efficiency,which is limited by the depth of penetration,is difficult to improve further.Backward Pressure Perturbations(BPPs)opposite to the propagation direction of Rotating Detonation Waves(RDWs)are produced by the reflection of the upstream oblique shock wave with the incoming stream and the hot release of local reactions after RDWs,which significantly affects the propagation mode and mixing.The RDWs propagate in the stable single-wave mode in configurations with 45 or 60 orifices and in the multi-wave mode in configurations with 30 orifices,whereas they fail in configurations with 15 orifices.Compared with that in the cold flow field,deceleration of the main flow,pressurization,and tangential velocity perturbation caused by the RDW substantially enhance the mixing efficiency.Moreover,the tangential velocity perturbations of upstream oblique shock waves and BPPs reduce the unevenness of the fuel distribution for the next cycle.This study reveals the mixing enhancement mechanism of RDWs and can contribute to the design of the injection scheme of the RDE. 展开更多
关键词 rotating detonation Ramjet engines MIXING Backward pressure perturbations Combustion instability
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Structural and Vibration Characteristics of Rotating Packed Beds System for Carbon Capture Applications Using Finite Element Method
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作者 Yunjun Lee Sanggyu Cheon Woo Chul Chung 《Computer Modeling in Engineering & Sciences》 2025年第12期3381-3403,共23页
The application of carbon capture systems on ships is technically constrained by limited onboard space and the weight of the conventional absorption tower.The rotating packed bed(RPB)has emerged as a promising alterna... The application of carbon capture systems on ships is technically constrained by limited onboard space and the weight of the conventional absorption tower.The rotating packed bed(RPB)has emerged as a promising alternative due to its small footprint and high mass transfer performance.However,despite its advantages,the structural and vibration stability of RPBs at high rotational speed remains insufficiently studied,and no international design standards currently exist for RPBs.To address this gap,this study performed a comprehensive finite element analysis(FEA)using ANSYS to investigate the structural and dynamic characteristics of an RPB.A three-dimensional model was developed to evaluate the effects of material selection(316 stainless steel,aluminum alloy,titanium alloy),bearing stiffness,and unbalanced mass on deformation,stress,and natural frequencies.In the structural analysis,316 stainless steel exhibited the highest von Mises stress and deformation.However,it was confirmed that all three materials did not exceed their yield strengths at the maximum rotating speed.Modal analysis and Campbell diagrams showed no resonance risk within the rated speed range,and increased bearing stiffness led to higher natural frequencies and improved stability.The findings provide quantitative design guidance for material selection,bearing stiffness optimization,and vibration control in high-rotational-speed RPB systems.This study contributes to establishing a foundational framework for the mechanical reliability and standardization of marine carbon capture units. 展开更多
关键词 rotating packed bed ROTORDYNAMICS finite element method structural analysis modal analysis VIBRATION bearing stiffness unbalance mass response analysis
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Review of Vibration Analysis and Structural Optimization Research for Rotating Blades
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作者 Saifeng Zhong Guoyong Jin +2 位作者 Yukun Chen Tiangui Ye Tuo Zhou 《哈尔滨工程大学学报(英文版)》 2025年第1期120-136,共17页
Blades are important parts of rotating machinery such as marine gas turbines and wind turbines,which are exposed to harsh environments during mechanical operations,including centrifugal loads,aerodynamic forces,or hig... Blades are important parts of rotating machinery such as marine gas turbines and wind turbines,which are exposed to harsh environments during mechanical operations,including centrifugal loads,aerodynamic forces,or high temperatures.These demanding working conditions considerably influence the dynamic performance of blades.Therefore,because of the challenges posed by blades in complex working environments,in-depth research and optimization are necessary to ensure that blades can operate safely and efficiently,thus guaranteeing the reliability and performance of mechanical systems.Focusing on the vibration analysis of blades in rotating machinery,this paper conducts a comprehensive literature review on the research advancements in vibration modeling and structural optimization of blades under complex operational conditions.First,the paper outlines the development of several modeling theories for rotating blades,including one-dimensional beam theory,two-dimensional plate-shell theory,and three-dimensional solid theory.Second,the research progress in the vibrational analysis of blades under aerodynamic loads,thermal environments,and crack factors is separately discussed.Finally,the developments in rotating blade structural optimization are presented from material optimization and shape optimization perspectives.The methodology and theory of analyzing and optimizing blade vibration characteristics under multifactorial operating conditions are comprehensively outlined,aiming to assist future researchers in proposing more effective and practical approaches for the vibration analysis and optimization of blades. 展开更多
关键词 rotating blade Vibration characteristics Structural optimization Harsh operating conditions REVIEW
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Thermal buckling, vibration and transient response of rotating GNPs-reinforced porous microbeams in thermal environment
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作者 Xu Zhang Chaofan Du +2 位作者 Liang Li Jianshi Fang Dingguo Zhang 《Acta Mechanica Sinica》 2025年第10期232-253,共22页
A comprehensive dynamic model for thermal buckling,elastic vibration and transient response analysis of rotating nanocomposite porous metal-matrix microbeams reinforced with graphene nanoplatelets(GNPs)under a uniform... A comprehensive dynamic model for thermal buckling,elastic vibration and transient response analysis of rotating nanocomposite porous metal-matrix microbeams reinforced with graphene nanoplatelets(GNPs)under a uniform thermal gradient is proposed.Various pore distribution patterns are considered together with different GNPs dispersion rules according to the specific functions.The extended rule of mixture and Halpin-Tsai micromechanics model are employed to evaluate the effective material properties of the nanocomposites.Based on the modified couple stress theory and the improved third-order shear deformation theory,the dynamic equations of the rotating microbeam are established by the Lagrange’s equation.The Chebyshev-based Galerkin method is adopted to discretize these equations,which are then solved by the complex modal analysis and Runge-Kutta-Merson method.Convergence study and comparisons with previous literature are conducted for validation of the present method.A parametric study performed analyzes the effects of angular velocity,thickness-to-length scale parameter ratio,porosity coefficient,weight fraction and geometry of GNPs together with distribution patterns of GNPs and pore on the critical buckling temperature rise,fundamental frequency and time-dependent response of the rotating nanocomposite microbeams.The results reveal significant effects of these parameters on the relevant mechanical behaviors,some of which are even contrary to expectations.Therefore,it is necessary to further study this kind of rotating nanocomposite structures for the optimal design. 展开更多
关键词 Porous metal-matrix nanocomposite Graphene nanoplatelets rotating microbeams Modified couple stress theory Dynamics Thermal buckling
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Improvement of rotating laser Al/steel lap welded joints via Cu interlayer:Microstructure and mechanical properties
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作者 Jiang YU Tao YANG +3 位作者 Bo LI Yuan ZHUANG Lin LI Yuan WANG 《Chinese Journal of Aeronautics》 2025年第12期531-543,共13页
The joining of Al/steel dissimilar metals has emerged as a critical challenge in automotive lightweight design.The sound Al/steel lap configuration joints were achieved via the new welding technology,i.e.,the rotating... The joining of Al/steel dissimilar metals has emerged as a critical challenge in automotive lightweight design.The sound Al/steel lap configuration joints were achieved via the new welding technology,i.e.,the rotating laser welding method,with the inserted Cu foil interlayer.The interfacial temperature fields of the obtained joints were accurately predicted by finite element simulation.The results indicate that the heat concentration effect at the interface was generated via the rotating laser,and the temperature difference of the laser direct irradiation area,the middle area,and the welding toe region was controlled to 100°C.Besides,the inserted Cu interlayer significantly optimized interfacial metallurgical reactions,resulting in the formation of a uniform composite interface layer consisting ofθ-(Fe,Cu)_(4)Al_(13),a-Al,and Al_(2)Cu.The thermodynamic calculations elucidated the sequential phase evolution:the Al-Fe binary system was generated first,and then followed by the Al-Cu binary system in the welding process.The final joint line load was enhanced with the inserted rotating laser.When the rotating diameter was 1 mm and the thickness of Cu interlayer was 10μm,the joint line load reached the maximum value of 297 N/mm. 展开更多
关键词 Al/steel Cu interlayer Dissimilar metals Finite element simulation Joint line load rotating laser
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The Relationship between Emotional Labor Strategies and Job Performance of Rotating Teachers:A Latent Profile Analysis
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作者 Huanfang Wang Xinyi Li +2 位作者 Fangfang Zhao Ximeng Cui Wei jian Li 《International Journal of Mental Health Promotion》 2025年第11期1813-1827,共15页
Background:In China,the policy of rotating teachers between urban and rural schools has been implemented to reduce educational disparities and ensure equitable access to quality education.These teachers face unique pr... Background:In China,the policy of rotating teachers between urban and rural schools has been implemented to reduce educational disparities and ensure equitable access to quality education.These teachers face unique professional and emotional challenges during the rotation process,making their emotional labor a critical factor influencing their job performance.This study aimed to explore the relationship between rotating teachers’emotional labor strategies and job performance.Methods:This study conducted a cross-sectional survey among 577 rotating teachers selected through stratified random sampling from primary and secondary schools in Chinese mainland.Date were collected using the Teacher Emotional Labor Scale and the Teacher Job Performance Scale.Latent profile analysis(LPA)was employed to identify distinct categories of emotional labor strategies:indifferent,moderately engaged,naturally invested,proactively adjusted,and emotionally elevated.Results:Teachers in the naturally invested and proactively adjusted types demonstrated relatively higher job performance scores,followed by those in the emotionally elevated type.In contrast,teachers in the indifferent and moderate engagement types exhibited comparatively lower scores(F=25.858,p<0.001,η^(2)=0.153).These findings indicate a practical significance,suggestion that flexible and adaptive use emotional labor strategies is strongly associated with enhanced job performance.Conclusion:This study demonstrates that rotating teachers’job performance differs significantly across distinct emotional labor profiles,with balanced and adaptive emotional regulation emerging as a key determinant of higher performance.By identifying and characterizing individual-centered emotional labor profiles,the study advances understanding of how emotional regulation contributes to teachers’professional effectiveness.These results underscore the importance of providing systematic and personalized support to help rotating teachers develop adaptive emotional regulation skills.Targeted guidance should enable teachers to appropriately express and adjust their emotions,thereby avoiding both excessive and insufficient emotional labor and promoting sustainable professional development. 展开更多
关键词 rotating teacher emotional labor strategies job performance latent profile analysis emotional regulation
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High-performance triboelectric nanogenerator based on a rotating-switch structure for efficient wind energy harvesting
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作者 Juan Pan Wuliang Sun +5 位作者 Ying Zhan Xiaoxia Lv Xin Li Yaxin Huang Baodong Chen Ding Nan 《Energy Materials and Devices》 2025年第2期72-82,71,共12页
Existing nanogenerator technologies for harvesting high-power energy from wind encounter significant chal-lenges due to limitations in current output.Here,we propose a rotating-switch triboelectric nanogenerator(RS-TE... Existing nanogenerator technologies for harvesting high-power energy from wind encounter significant chal-lenges due to limitations in current output.Here,we propose a rotating-switch triboelectric nanogenerator(RS-TENG)that uses mechanical triggering switches(on-off-on)to enhance the instantaneous current pulses during rotation.The rotating-switch in the proposed device addresses the issue of low instantaneous current output in triboelectric nanogenerators while maintaining voltage stability.At a constant rotational speed,the RS-TENG achieves an instantaneous current of 3.2 times that of its nonswitching counterpart,with an 89%reduction in response time.Furthermore,at a wind speed of 2 m·s^(-1),the RS-TENG achieves a wind power density of 10.4 mW·m^(-2)·m^(-1)·s.Additionally,by integrating the RS-TENG with energy management circuits,the nanogenerator can power wireless signal transmitters and temperature sensors,offering a self-sustaining power solution for remote wireless services.This research presents a promising technology for powering electronic devices in energy-scarce environments. 展开更多
关键词 triboelectric nanogenerator rotating switches instantaneous current generation power density self-powered sensing systems
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Hot tearing behavior and mechanism of AXJ530 alloy under rotating magnetic field
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作者 Xudong Du Zhenyao Xu +5 位作者 Feng Wang Shengwei Bai Le Zhou Xiaoqi Kang Zhi Wang Jinwei Li 《Journal of Magnesium and Alloys》 2025年第4期1757-1770,共14页
In order to solve the issues concerning high hot tearing susceptibility(HTS)of Mg-Al-Ca series alloys,a rotating magnetic field(RMF)was applied during their solidification.The effect of RMF at different excitation cur... In order to solve the issues concerning high hot tearing susceptibility(HTS)of Mg-Al-Ca series alloys,a rotating magnetic field(RMF)was applied during their solidification.The effect of RMF at different excitation current intensities(50 A,100 A,and 150 A)on the solidification and hot tearing behavior of AXJ530(Mg-5Al-3Ca-0.17Sr)alloy was investigated.The results indicated that the HTS of AXJ530 alloy decreased with the increase of excitation current intensity.This aspect can be attributed to significant grain refinement under the action of RMF,which improved the intergranular bonding and relieved the stress concentration.On the other hand,the stirring effect of the electromagnetic force on the melt could break up the developed dendrites and delay the dendrite coherence,as well as optimize the feeding channels and improve the feeding drive of the residual liquid at the end of solidification.Therefore,under the action of RMF,the hot tearing initiation of the alloy was suppressed and the feeding efficiency of the liquid was greatly improved,which led to a noticeable reduction of the HTS of the alloy.Moreover,no significant hot tearing was detected in castings at the excitation current parameters of 150 A and 10 Hz. 展开更多
关键词 AXJ530 alloy Hot tearing susceptibility MICROSTRUCTURE rotating magnetic field Thermal analysis
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Effect of Rotating Magnetic Field on the Microstructure and Shear Property of Al/Steel Bimetallic Composite by Compound Casting
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作者 Weize Lv Guowei Zhang +3 位作者 Heqian Song Dan Zhang Shiyuan Liu Hong Xu 《Acta Metallurgica Sinica(English Letters)》 2025年第2期276-286,共11页
Al/steel bimetallic composites were prepared by compound casting,and the effects of the rotating magnetic field on the interfacial microstructure and shear property of bimetallic composite was investigated.The applica... Al/steel bimetallic composites were prepared by compound casting,and the effects of the rotating magnetic field on the interfacial microstructure and shear property of bimetallic composite was investigated.The application of rotating magnetic field refined the grain structure of the Al alloy matrix,changed the eutectic Si morphology from coarse lath to needle-like.The rotating magnetic field improved the temperature field and solute distribution of the Al alloy melt,enriched a layer of Si at the interface,and suppressed the growth of intermetallic compounds,the thickness of the interface layer decreased from 44.9μm to 22.8μm.The interfacial intermetallic compounds consisted ofη-Al_(5)Fe_(2),θ-Al_(13)Fe_(4),τ6-Al_(4.5)FeSi,τ_(5)-Al_(8)Fe_(2)Si andτ_(3)-Al_(2)FeSi,and the addition of the rotating magnetic field did not change phase composition.The rotating magnetic field improved the stress distribution within the interfacial intermetallic compounds,the presence of high-angle grain boundaries retarded crack extension,and the shear strength was enhanced from 31.27±3 MPa to 52.70±4 MPa.This work provides a feasible method for preparing Al/steel bimetallic composite with good bonding property. 展开更多
关键词 Al/steel bimetallic composite rotating magnetic field Intermetallic compounds Interface Compound casting
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The role of isolators in two-phase kerosene/air rotating detonation engines
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作者 Wenbo Cao Fang Wang +1 位作者 Chunsheng Weng Huangwei Zhang 《Defence Technology(防务技术)》 2025年第7期260-274,共15页
In this study, the three-dimensional non-premixed two-phase kerosene/air rotating detonation engines with different isolator configurations and throat area ratios are simulated by the Eulerian-Lagrangian method. The e... In this study, the three-dimensional non-premixed two-phase kerosene/air rotating detonation engines with different isolator configurations and throat area ratios are simulated by the Eulerian-Lagrangian method. The effects of the divergence, straight, and convergence isolators on the rotating detonation wave dynamics and the upstream oblique shock wave propagation mechanism are analyzed. The differences in the rotating detonation wave behaviors between ground and flight operations are clarified.The results indicate that the propagation regimes of the upstream oblique shock wave depend on the isolator configurations and operation conditions. With a divergence isolator, the airflow is accelerated throughout the isolator and divergence section, leading to a maximum Mach number(~1.8) before the normal shock. The total pressure loss reaches the largest, and the detonation pressure drops. The upstream oblique shock wave can be suppressed within the divergence section with the divergence isolator.However, for the straight and convergence isolators, the airflow in the isolator with a larger ψ_(1)(0.3 and0.4) can suffer from the disturbance of the upstream oblique shock wave. The critical incident angle is around 39° at ground operation conditions. The upstream oblique shock wave tends to be suppressed when the engine operates under flight operation conditions. The critical pressure ratio β_(cr0) is found to be able to help in distinguishing the propagation regimes of the upstream oblique shock wave. Slightly below or above the β_(cr0) can obtain different marginal propagation results. The high-speed airflow in the divergence section affects the fuel droplet penetration distance, which deteriorates the reactant mixing and the detonation area. Significant detonation velocity deficits are observed and the maximum velocity deficit reaches 26%. The results indicate the engine channel design should adopt different isolator configurations based on the purpose of total pressure loss or disturbance suppression. This study can provide useful guidance for the channel design of a more complete two-phase rotating detonation engine. 展开更多
关键词 rotating detonation TWO-PHASE ISOLATOR Upstream oblique shock wave
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Robust Anomaly Detection of Rotating Machinery with Contaminated Data
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作者 Jingcheng Wen Jiaxin Ren +1 位作者 Zhibin Zhao Xuefeng Chen 《Journal of Dynamics, Monitoring and Diagnostics》 2025年第3期170-182,共13页
Rotating machinery is critical to industrial systems,necessitating robust anomaly detection(AD)to ensure operational safety and prevent failures.However,in real-world scenarios,monitoring data is typically unlabeled a... Rotating machinery is critical to industrial systems,necessitating robust anomaly detection(AD)to ensure operational safety and prevent failures.However,in real-world scenarios,monitoring data is typically unlabeled and often consists of normal samples contaminated with a small proportion of unknown anomalies.To address this,this paper proposes a diffusion-based AD method,Anomaly Detection Denoising Diffusion Probabilistic Model(AD-DDPM)for robust AD.The method employs a U-attention-net to capture local and global features and introduces a filtered contrastive mechanism to mitigate the impact of contaminated training data.By leveraging the probabilistic nature of diffusion models,AD-DDPM effectively models normal data distributions,achieving superior AD even with polluted samples.Experimental validation on fault simulation datasets demonstrates the method’s exceptional performance,outperforming traditional machine learning and deep learning baselines.The proposed approach offers a promising solution for reliable health monitoring in industrial settings. 展开更多
关键词 anomaly detection contaminated data diffusion model rotating machinery
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Influence of rotating magnetic field on microstructure and strength-ductility synergy in wide liquidus-solidus interval phosphor bronze
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作者 Guoliang Li Jinchuan Jie +5 位作者 Jian Liu Mingfei Wang Zidi Hang Jia Liu Zhongkai Guo Tingju Li 《Journal of Materials Science & Technology》 2025年第21期216-221,共6页
Phosphor bronze is a commonly used elastic copper alloy,widely applied in electronic connectors and terminals[1-4].With the rapid development of 5 G mobile communication technology and the new energy vehicle industry,... Phosphor bronze is a commonly used elastic copper alloy,widely applied in electronic connectors and terminals[1-4].With the rapid development of 5 G mobile communication technology and the new energy vehicle industry,the size requirements for connectors have been reduced,while the demand for strength has gradually increased[5].This requires the alloy to possess higher strength and better deformability. 展开更多
关键词 electronic connectors g mobile communication technology rotating magnetic field strength ductility synergy MICROSTRUCTURE copper alloywidely phosphor bronze new energy vehicle
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Enhanced degradation of chloramphenicol wastewater in a submerged rotating packed bed reactor:O_(3)/PDS synergistic oxidation
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作者 Zhuolin Yang Zhenyu Yang +2 位作者 Yanbin Li Guangwen Chu Jianfeng Chen 《Chinese Journal of Chemical Engineering》 2025年第6期176-184,共9页
The large molecular weight and high hydrophilicity of chloramphenicol(CAP) residuals in wastewater led to severe degradation difficulty,which propelled the development of new wastewater degradation processes and react... The large molecular weight and high hydrophilicity of chloramphenicol(CAP) residuals in wastewater led to severe degradation difficulty,which propelled the development of new wastewater degradation processes and reactors based on process intensification.This study enhanced the CAP degradation by ozone/peroxydisulfate(PDS) advanced oxidation process in a submerged rotating packed bed(SRPB)reactor.Compared the usage of different oxidants,it was indicated that the combination of O_(3) and PDS exhibited a higher degradation efficiency than ozone and PDS alone.The more desired degradation efficiency could be achieved at the operating conditions of ascending PDS concentration,SRPB rotational speed,ozone concentration,reduced initial CAP concentration,and the water qualities of ascended pH,lower Cl^(-)and initial CO_(3)^(2-) concentrations.Under the optimized conditions of C_(CAP)=20 mg·L^(-1),C_(O3)=30 mg·L^(-1),C_(PDS)=100 mg·L^(-1),and N=400 r·min^(-1),and water qualities of pH=10,the maximum chloramphenicol degradation efficiency of 97% and kinetic constant of 0.23 min^(-1) were achieved after treating 16 min.A comparison of the results with previously reported advanced oxidation processes of CAP indicated that the enhanced O^(3)/PDS advanced oxidation system using the SRPB can significantly improve the degradation efficiency of CAP. 展开更多
关键词 Chloramphenicol wastewater OZONATION Advanced oxidation process Degradation efficiency Submerged rotating packed bed
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Separation of rotating and stationary sound sources based on robust principal component analysis
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作者 Fangli NING Weizhe ZHENG +1 位作者 Hongjie HOU Yang WANG 《Chinese Journal of Aeronautics》 2025年第8期217-230,共14页
Traditional beamforming techniques may not accurately locate sources in scenarios with both stationary and rotating sound sources.The existence of rotating sound sources can cause blurring in the stationary beamformin... Traditional beamforming techniques may not accurately locate sources in scenarios with both stationary and rotating sound sources.The existence of rotating sound sources can cause blurring in the stationary beamforming map.Current algorithms for separating different moving sound sources have limited effectiveness,leading to significant residual noise,especially when the rotating source is strong enough to mask stationary sources completely.To overcome these challenges,a novel solution utilizing a virtual rotating array in the modal domain combined with robust principal component analysis is proposed to separate sound sources with different rotational speeds.This approach,named Robust Principal Component Analysis in the Modal domain(RPCA-M),investigates the performance of convex nuclear norm and non-convex Schatten-p norm to distinguish stationary and rotating sources.By comparing the errors in Cross-Spectral Matrix(CSM)recovery and acoustic imaging across different algorithms,the effectiveness of RPCA-M in separating stationary and moving sound sources is demonstrated.Importantly,this method effectively separates sound sources,even when there are significant variations in their amplitudes at different rotation speeds. 展开更多
关键词 BEAMFORMING Cross-spectral matrix Virtual rotating array Robust principal component analysis Separation of sources
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Arc morphology and properties of plasma arc welding of Q235B steel via rotating tungsten electrode
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作者 Hongyu Wang Yu Sun +6 位作者 Guang Ma Dawei Wang Hongtao Zhang Xiaoya Tang Siheng Tan Rongmao Du Yuxiao Zhu 《China Welding》 2025年第3期217-228,共12页
A high-quality welding method,named plasma arc welding apparatus with rotating tungsten electrode(abbreviated as PAW-RT),was proposed in this paper.The rotation speed could be adjusted from 0 to 15000 r/min.The rotary... A high-quality welding method,named plasma arc welding apparatus with rotating tungsten electrode(abbreviated as PAW-RT),was proposed in this paper.The rotation speed could be adjusted from 0 to 15000 r/min.The rotary motion of the tungsten needle trans-ferred circumferential momentum to the arc as well as the molten pool,thereby conferring the latter with rotating fluid flow charac-teristics.The influences of tungsten electrode rotation speed on PAW arc morphology,weld formation and interfacial microstructure of the final weld joints were discussed by the experimental procedures involving in-situ ablation,surfacing and butt welding.The ex-periments were conducted on Q235B steel.The results indicated that the increase of tungsten electrode rotation speed in PAW-RT contributed to improving arc eccentricity,leading to aesthetically improved welds with more uniformity.Additionally,the strength,hardness and toughness of the welded joint increased,while porosity was reduced. 展开更多
关键词 rotating tungsten electrode Arc morphology Microstructure characteristics Mechanical properties
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Nonlinear effect analysis and compensation based on improved friction observer for torque rotating stage
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作者 Yingjie Jia Bo Liu +1 位作者 Hui Tang Yuzhang Wei 《Nanotechnology and Precision Engineering》 2025年第3期138-148,共11页
In semiconductor precision packaging and other applications involving alignment of automated equipment,the nonlinear motion caused by structural characteristics and friction effects on torque-type rotating motion stag... In semiconductor precision packaging and other applications involving alignment of automated equipment,the nonlinear motion caused by structural characteristics and friction effects on torque-type rotating motion stages seriously affects output accuracy and stability.To solve this problem,the motion characteristics of a rotating stage and the mechanism by which friction nonlinearity influences accuracy are analyzed in detail.In addition,a compound control strategy based on a kinematic model and the Stribeck friction model is designed.A friction disturbance observer based on output position feedback is improved for simple parameter tuning.Finally,an experimental system is constructed to carry out validation tests,including identification of nonlinear characteristics and performance comparisons.The experimental results show that the linear tracking error of the torque-type rotating stage is less than 1.47µm after adoption of the proposed model-based composite control strategy,and the corresponding rotary angle deviation is less than 0.0153°.The linearity of output motion is increased to 97.59%and the error compensation effect is improved by 51.6%compared with the PID control method.The experimental results confirm that the analysis method adopted here and the proposed compensation strategy can effectively reduce frictional nonlinearity and improve motion accuracy.The proposed method can also be applied to other precision electromechanical systems. 展开更多
关键词 rotating stage Mechanical analysis Frictional nonlinear effect Disturbance observation
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Observation on the Clinical Efficacy of Moist Burn Ointment Combined with Rotating Moxibustion in the Treatment of Pressure Ulcers with Deficiency of Qi and Blood
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作者 Song Li Dingxing Zhou 《Journal of Clinical and Nursing Research》 2025年第5期311-318,共8页
Objective:To observe the therapeutic effect of Moist Burn Ointment combined with rotating moxibustion on patients with pressure ulcers and deficiency of both Qi and blood.Methods:40 patients with pressure ulcers and d... Objective:To observe the therapeutic effect of Moist Burn Ointment combined with rotating moxibustion on patients with pressure ulcers and deficiency of both Qi and blood.Methods:40 patients with pressure ulcers and deficiency of both Qi and blood were randomly divided into two groups from July 2024 to November 2025.Group A received Moist Burn Ointment combined with rotating moxibustion,while Group B received Moist Burn Ointment only.Results:Group A showed better efficacy,wound healing time,dressing change frequency,satisfaction,PUSH score,and adverse reaction indicators compared to Group B(P<0.05).Conclusion:The combination of Moist Burn Ointment and rotating moxibustion in the treatment of patients with pressure ulcers and deficiency of both Qi and blood can shorten wound healing time,reduce dressing change frequency,and alleviate the degree of pressure ulcers,which is safe and efficient. 展开更多
关键词 Pressure ulcer Deficiency of both Qi and blood rotating moxibustion Moist Burn Ointment EFFICACY
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Partial rotating instability in a boundary layer ingesting fan
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作者 Hefang DENG Songan ZHANG +3 位作者 Kailong XIA Xiaoqing QIANG Mingmin ZHU Jinfang TENG 《Chinese Journal of Aeronautics》 2025年第3期43-64,共22页
Rotating Instability (RI) is a typical unsteady flow phenomenon in compressors and may cause severe aerodynamic noise and even potential nonsynchronous vibration. Most studies of RI are based on the uniform inflow, ig... Rotating Instability (RI) is a typical unsteady flow phenomenon in compressors and may cause severe aerodynamic noise and even potential nonsynchronous vibration. Most studies of RI are based on the uniform inflow, ignoring the influence of inlet distortions. This study investigates the mechanism of RI in a transonic rotor through full-annulus unsteady simulations, with a particular focus on the effects of boundary layer ingesting distortions. The results show that at the uniform inflow, the RI fluctuations with the broadband hump can be observed over a relatively wide mass flow rate range, and its origin can be attributed to the coupling effect between the tip leakage flow and shear layer instability. At the inlet distortions, the broadband hump only occurs with partial circumferential locations. This kind of flow phenomenon is defined as Partial Rotating Instability (PRI). The PRI only occurs in a narrower mass flow rate range in which the circumferential range of strong shear is sufficiently large and the self-induced unsteady effects are strong enough. Further, this study confirms that the averaged tip leakage flow axial momentum at the onset of RI or PRI is close, so it can be used as the parameter to determine whether RI or PRI occurs. 展开更多
关键词 rotating instability Boundary layer ingesting fan Tip leakage fAow Shear layer instability Full-annulus unsteady simnulation
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Active vibration control for rotating machines with current-controlled electrodynamic actuators and velocity feedback of the machine feet based on a generalized mathematical formulation
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作者 Ulrich Werner 《Control Theory and Technology》 2025年第1期1-27,共27页
A theoretical analysis regarding active vibration control of rotating machines with current-controlled electrodynamic actuators between machine feet and steel frame foundation and with velocity feedback of the machine... A theoretical analysis regarding active vibration control of rotating machines with current-controlled electrodynamic actuators between machine feet and steel frame foundation and with velocity feedback of the machine feet vibrations is presented.First,a generalized mathematical formulation is derived based on a state-space description which can be used for different kinds of models(1D,2D,and 3D models).It is shown that under special boundary conditions,the control parameters can be directly implemented into the stiffness and damping matrices of the system.Based on the generalized mathematical formulation,an example of a rotating machine—described by a 2D model—with journal bearings,flexible rotor,current-controlled electrodynamic actuators,steel frame foundation,and velocity feedback of the machine feet vibrations is presented where the effectiveness of the described active vibration control system is demonstrated. 展开更多
关键词 Active vibration control rotating machines Current-controlled electrodynamic actuators Steel frame foundation
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