The excessive buildup of neurotoxicα-synuclein plays a pivotal role in the pathogenesis of Parkinson's disease,highlighting the urgent need for innovative therapeutic strategies to promoteα-synuclein clearance,p...The excessive buildup of neurotoxicα-synuclein plays a pivotal role in the pathogenesis of Parkinson's disease,highlighting the urgent need for innovative therapeutic strategies to promoteα-synuclein clearance,particularly given the current lack of disease-modifying treatments.The glymphatic system,a recently identified perivascular fluid transport network,is crucial for clearing neurotoxic proteins.This review aims to synthesize current knowledge on the role of the glymphatic system inα-synuclein clearance and its implications for the pathology of Parkinson's disease while emphasizing potential therapeutic strategies and areas for future research.The review begins with an overview of the glymphatic system and details its anatomical structure and physiological functions that facilitate cerebrospinal fluid circulation and waste clearance.It summarizes emerging evidence from neuroimaging and experimental studies that highlight the close correlation between the glymphatic system and clinical symptom severity in patients with Parkinson's disease,as well as the effect of glymphatic dysfunction onα-synuclein accumulation in Parkinson's disease models.Subsequently,the review summarizes the mechanisms of glymphatic system impairment in Parkinson's disease,including sleep disturbances,aquaporin-4 impairment,and mitochondrial dysfunction,all of which diminish glymphatic system efficiency.This creates a vicious cycle that exacerbatesα-synuclein accumulation and worsens Parkinson's disease.The therapeutic perspectives section outlines strategies for enhancing glymphatic activity,such as improving sleep quality and pharmacologically targeting aquaporin-4 or its subcellular localization.Promising interventions include deep brain stimulation,melatonin supplementation,γ-aminobutyric acid modulation,and non-invasive methods(such as exercise and bright-light therapy),multisensoryγstimulation,and ultrasound therapy.Moreover,identifying neuroimaging biomarkers to assess glymphatic flow as an indicator ofα-synuclein burden could refine Parkinson's disease diagnosis and track disease progression.In conclusion,the review highlights the critical role of the glymphatic system inα-synuclein clearance and its potential as a therapeutic target in Parkinson's disease.It advocates for further research to elucidate the specific mechanisms by which the glymphatic system clears misfoldedα-synuclein and the development of imaging biomarkers to monitor glymphatic activity in patients with Parkinson's disease.Findings from this review suggest that enhancing glymphatic clearance is a promising strategy for reducingα-synuclein deposits and mitigating the progression of Parkinson's disease.展开更多
Joint clearances in antenna pointing mechanisms lead to uncertainty in function deviation. Current studies mainly focus on radial clearance of revolute joints, while axial clearance has rarely been taken into consider...Joint clearances in antenna pointing mechanisms lead to uncertainty in function deviation. Current studies mainly focus on radial clearance of revolute joints, while axial clearance has rarely been taken into consideration. In fact, own?ing to errors from machining and assembly, thermal deformation and so forth, practically, axial clearance is inevitable in the joint. In this study, an error equivalent model(EEM) of revolute joints is proposed with considering both radial and axial clearances. Compared to the planar model of revolute joints only considering radial clearance, the journal motion inside the bearing is more abundant and matches the reality better in the EEM. The model is also extended for analyzing the error distribution of a spatial dual?axis("X–Y" type) antenna pointing mechanism of Spot?beam antennas which especially demand a high pointing accuracy. Three case studies are performed which illustrates the internal relation between radial clearance and axial clearance. It is found that when the axial clearance is big enough, the physical journal can freely realize both translational motion and rotational motion. While if the axial clearance is limited, the motion of the physical journal will be restricted. Analysis results indicate that the consideration of both radial and axial clearances in the revolute joint describes the journal motion inside the bearing more precise. To further validate the proposed model, a model of the EEM is designed and fabricated. Some suggestions on the design of revolute joints are also provided.展开更多
The inner and outer oil film dynamic characteristic coefficients of floating ring bearings（FRBs） change due to the manufacturing tolerance of the floating ring, journal and intermediate, which leads to high-speed tu...The inner and outer oil film dynamic characteristic coefficients of floating ring bearings（FRBs） change due to the manufacturing tolerance of the floating ring, journal and intermediate, which leads to high-speed turbocharger＇s vibration too large and even causes nonlinear vibration accident. However, the investigation of floating ring bearing manufacturing tolerance clearance on the rotordynamic characteristics is less at present. In order to study the influence law of inner and outer clearance on turbocharger vibration, the rotor dynamic motion equations of turbocharger supported in FRBs are derived by analyzing the size relations between floating ring, journal and intermediate for the inner and outer oil film clearances, the time transient response analysis for combination of FRBs clearance are developed. A realistic turbocharger is taken as a research object, the FE model of the turbocharger with FRBs is modeled. Under the conditions of four kinds of limit state bearing clearances for inner and outer oil film, the nonlinear transient analyses are performed based on the established FE dynamic models of the nonlinear rotor-FRBs system applied incentive combinations of gravity and unbalance force, respectively. From the waterfall, the simulation results show that the speed for the appearance of fractional frequency is not identical and the amplitude magnitude is different under the four kinds of bearing manufacturing tolerance limit clearances, and fractional frequency does not appear in the turbocharger and the amplitude is minimum under the ODMin/IDMax bearing manufacturing tolerance clearances. The turbocharger vibration is reduced by controlling the manufacturing tolerance clearance combinations of FRBs, which is helpful for the dynamic design and production-manufacturing of high-speed turbocharger.展开更多
This paper uses the topology theory to analyze the surface flowspectrums of straight, positively curved and negatively curvedcascades with relative tip clearances of 0.023 and 0.036, findsapparent differences of topol...This paper uses the topology theory to analyze the surface flowspectrums of straight, positively curved and negatively curvedcascades with relative tip clearances of 0.023 and 0.036, findsapparent differences of topology and vortex structures in the bladetip and the suction side wall corner of single type of cascade withthis two clearances, and studies the mechanism of the differenceformation as well as their effects o the energy loss.展开更多
It has been well known that nozzle end-clearances in a Variable Nozzle Turbine（VNT）are unfavorable for aerodynamic performance, especially at small openings, and efforts to further decrease size of the clearances ar...It has been well known that nozzle end-clearances in a Variable Nozzle Turbine（VNT）are unfavorable for aerodynamic performance, especially at small openings, and efforts to further decrease size of the clearances are very hard due to thermal expansion. In this paper, both the different sizes of nozzle end-clearances and the various ratios of their distribution at the hub and shroud sides were modelled and investigated by performing 3D Computational Fluid Dynamics（CFD） and Finite Element Analysis（FEA） simulations with a code of transferring the aerodynamic pressure from the CFD results to the FEA calculations. It was found that increasing the size of the nozzle end-clearances divided equally at the hub and shroud sides deteriorates turbine efficiency and turbine wheel reliability, yet increases turbine flow capacity. And, when the total nozzle endclearances remain the same, varying nozzle end-clearances＇ distribution at the hub and shroud sides not only shifts operation point of a VNT turbine, but also affects the turbine wheel vibration stress.Compared with nozzle hub clearance, the shroud clearance is more sensitive to both aerodynamic performance and reliability of a VNT turbine. Consequently, a possibility is put forward to improve VNT turbine efficiency meanwhile decrease vibration stress by optimizing nozzle end-clearances＇ distribution.展开更多
To investigate the effect of tip clearance size on cavitation characteristics in a turbopump inducer,a series of experiments have been conducted in a newly developed visualization test facility using room temperature ...To investigate the effect of tip clearance size on cavitation characteristics in a turbopump inducer,a series of experiments have been conducted in a newly developed visualization test facility using room temperature water as working fluid.The pressure fluctuations near the tip region were collected,and the cavity structures under various conditions were documented by a high-speed camera.It is found that large tip clearance distinctly reduces both the non-cavitation and cavitation performance.Three cavitation instabilities,super-synchronous rotating cavitation,synchronous rotating cavitation and cavitation surge have been carefully identified through combination of cross-correlation analysis of pressure signals and visualization results.Large tip clearance displays a remarkable stabilization effect on pressure fluctuation,cavitation surge totally disappears,and the range of occurrence of synchronous rotating cavitation becomes smaller for the large tip clearance,whereas super-synchronous rotating cavitation only occurs in the large tip clearance.The cavitation areas are smaller at large tip clearance,while the flow channels are more seriously choked when cavitation occurs heavily in comparison with those at small tip clearance,which may be responsible for the worse cavitation performance.展开更多
This paper is concerned with the determination of the normal force-displacement （NFD） relation for the contact problem of cylindrical joints with clearance. A simple formulation for this contact problem is developed...This paper is concerned with the determination of the normal force-displacement （NFD） relation for the contact problem of cylindrical joints with clearance. A simple formulation for this contact problem is developed by modeling the pin as a rigid wedge and the elastic plate as a simple Winkler elastic foundation. The numerical results show that the normal displacement relation based on Hertz theory is only valid for the case of large clearance with a small normal load, and the NFD relation based on Persson theory is only effective in the case of very small clearance. The proposed approximate model in this paper gives better results than Hertz theory and Persson theory in a large range of clearances as seen from the comparison with the results of FEM.展开更多
A new non-linear transverse-torsional coupled model was proposed for 2K-H planetary gear train, and gear's geometric eccentricity error, comprehensive transmission error, time-varying meshing stiffness, sun-planet...A new non-linear transverse-torsional coupled model was proposed for 2K-H planetary gear train, and gear's geometric eccentricity error, comprehensive transmission error, time-varying meshing stiffness, sun-planet and planet-ring gear pair's backlashes and sun gear's bearing clearance were taken into consideration. The solution of differential governing equation of motion was solved by applying variable step-size Runge-Kutta numerical integration method. The system motion state was investigated systematically and qualitatively, and exhibited diverse characteristics of bifurcation and chaos as well as non-linear behavior under different bifurcation parameters including meshing frequency, sun-planet backlash, planet-ring backlash and sun gear's bearing clearance. Analysis results show that the increasing damping could suppress the region of chaotic motion and improve the system's stability significantly. The route of crisis to chaotic motion was observed under the bifurcation parameter of meshing frequency. However, the routes of period doubling and crisis to chaos were identified under the bifurcation parameter of sun-planet backlash; besides, several different types of routes to chaos were observed and coexisted under the bifurcation parameter of planet-ring backlash including period doubling, Hopf bifurcation, 3T-periodic channel and crisis. Additionally, planet-ring backlash generated a strong coupling effect to system's non-linear behavior while the sun gear's bearing clearance produced weak coupling effect. Finally, quasi-periodic motion could be found under all above–mentioned bifurcation parameters and closely associated with the 3T-periodic motion.展开更多
A new nonlinear transverse-torsional coupled model with backlash and bearing clearance was proposed for planetary gear set. Meanwhile, sun gear and planet's eccentricity errors, static transmission error, and time...A new nonlinear transverse-torsional coupled model with backlash and bearing clearance was proposed for planetary gear set. Meanwhile, sun gear and planet's eccentricity errors, static transmission error, and time-varying meshing stiffness were taken into consideration. The differential governing equations of motion were solved by employing variable step-size Rung-Kutta numerical integration method. The behavior of dynamic load sharing characteristics affected by the system parameters including input rate, sun gear's supporting stiffness and eccentricity error, planet's eccentricity error, sun gear's bearing clearance, backlashes of sun-planet and planet-ring meshes were investigated qualitatively and systematically. Some theoretical results are summarized at last which extend the current understanding of the dynamic load sharing behavior of planet gear train, enrich the related literature and provide references for the design of planetary gear train.展开更多
This article reports on track-monitoring and analyzing machine clearances during wood forwarding across seasons and weather, using ultrasonic distance sensors in combination with time-stamped GPS xy locations, at 10 s...This article reports on track-monitoring and analyzing machine clearances during wood forwarding across seasons and weather, using ultrasonic distance sensors in combination with time-stamped GPS xy locations, at 10 sec intervals. The resulting data, obtained from 54 harvesting blocks, were analyzed by machine type (two wood forwarders and one grapple skidder), stand type (softwood plantation versus natural hardwood stands), month, slope, cartographic depth-to-water (DTW) classes, number of passes along track, and machine speed. For the most part, clearances were highly variable, due to passing over stumps, rocks, harvest slash, brushmats, ruts, and snow cover when present. This variability was on average greater for the lighter-weight wood forwarders than for the heavier-weight skidder, with the former mostly moving along equally spaced lines on brushmats, while the paths of the latter spread away from central wood-landing sites. In terms of trends, machines moved 1) more slowly on wet ground, 2) faster during returning than forwarding, and 3) fastest along wood-landing roads, as to be expected. Low clearances were most notable during winter on snow-covered ground, and on non-frozen shallow DTW and wet multiple-pass ground. During dry weather conditions, clearances also increased from low-pass tracks to multi-pass tracks due to repeat soil compaction of broadened tracks. These results are presented block-by-block and by machine type. Each block-based clearance frequency pattern was quantified through regression analysis and using a gamma probability distribution function.展开更多
There are clearances in mechanism because of manufacture and assembly error,which reduces operation life and working accuracy of mechanism and has a great impact on dynamical responses.At the moment,research in this a...There are clearances in mechanism because of manufacture and assembly error,which reduces operation life and working accuracy of mechanism and has a great impact on dynamical responses.At the moment,research in this area mainly focuses on single degree⁃of⁃freedom mechanism considering one clearance,while research of multi⁃DOF mechanism considering multi⁃clearance is less.With the purpose of studying the dynamical characteristics of complex multi⁃DOF mechanism with multi⁃clearances,a dynamic model was developed.The dynamic responses of 2⁃DOF mechanism with two clearances under different positions,values,and numbers of clearance were analyzed.The displacement,velocity,acceleration,collision force,and the axis trajectory at clearance were then given.In addition,there is a limited amount of literature on chaotic phenomena,which mainly focuses on the chaotic phenomena of end⁃effector of mechanism.But in this paper,the non⁃linear characteristics were analyzed by chaotic phenomenon of clearance joint,then chaotic phenomenon was identified by Poincarémappings and phase diagrams.Bifurcation diagrams were given.The results will offer a reliable technical support for the study of dynamical responses of planar mechanisms and the analysis of chaotic phenomena.展开更多
Alzheimer's disease,the primary cause of dementia,is characterized by neuropathologies,such as amyloid plaques,synaptic and neuronal degeneration,and neurofibrillary tangles.Although amyloid plaques are the primar...Alzheimer's disease,the primary cause of dementia,is characterized by neuropathologies,such as amyloid plaques,synaptic and neuronal degeneration,and neurofibrillary tangles.Although amyloid plaques are the primary characteristic of Alzheimer's disease in the central nervous system and peripheral organs,targeting amyloid-beta clearance in the central nervous system has shown limited clinical efficacy in Alzheimer's disease treatment.Metabolic abnormalities are commonly observed in patients with Alzheimer's disease.The liver is the primary peripheral organ involved in amyloid-beta metabolism,playing a crucial role in the pathophysiology of Alzheimer's disease.Notably,impaired cholesterol metabolism in the liver may exacerbate the development of Alzheimer's disease.In this review,we explore the underlying causes of Alzheimer's disease and elucidate the role of the liver in amyloid-beta clearance and cholesterol metabolism.Furthermore,we propose that restoring normal cholesterol metabolism in the liver could represent a promising therapeutic strategy for addressing Alzheimer's disease.展开更多
Metamorphic mechanism has the advantages of variable topology and variable degrees of freedom, which can realize the requirements of multi-conditions and multi-tasks, and has a good application prospect. The configura...Metamorphic mechanism has the advantages of variable topology and variable degrees of freedom, which can realize the requirements of multi-conditions and multi-tasks, and has a good application prospect. The configuration transformation is prominent feature of the metamorphic mechanism. The number of constraints or properties of the kinematic pairs provided by the metamorphic kinematic pairs will change under certain conditions, its dynamic performance is much more complex than that of traditional kinematic pairs with immutable constraints. However, the clearance model about traditional kinematic pairs with immutable constraints established by long-term research is difficult to be directly applied to the metachromatic kinematic pairs. Referring to the experience of the traditional kinematic pairs with immutable constraints, the continuous contact model of Metamorphic Groove pin pair with clearance is established. According to the traditional continuous contact model of the kinematic pairs with immutable constraints, the forces between the elements of kinematic pair of the mechanism with clearance and the ideal mechanism without clearance are regarded as the same, and the inertia force and inertia moment of the components are also calculated according to the acceleration of the ideal mechanism. The clearance is regarded as a massless virtual bar with length r. For the rotating pair part, the massless virtual bar length r is the difference between the radius of the shaft and the hole, and for the sliding pair part, the massless virtual bar length r is half of the difference between the height of the slider and the guide groove. According to the new mechanism without gap after adding the imaginary bar, kinetic energy and potential energy of the system are calculated for the two configurations of mechanism with metamorphic Groove pin pair with clearance. The kinetic energy and potential energy of the system are calculated according to the new mechanism without clearance after adding the massless virtual bar. The kinetic energy, potential energy and generalized force are substituted into the Lagrangian equation to obtain the motion equation of the metamorphic mechanism, which lays the foundation for the dynamic performance study of the mechanism with metamorphic groove pin pair with clearance.展开更多
Currently,it is still a challenge to develop an organic photosensitizer(PS)with outstanding near-infrared absorption,low O2dependence,precise tumor targeting and rapid clearance through the kidney to improve the overa...Currently,it is still a challenge to develop an organic photosensitizer(PS)with outstanding near-infrared absorption,low O2dependence,precise tumor targeting and rapid clearance through the kidney to improve the overall outcome of phototherapy.In this study,we have designed an organic PS(Nc PB)with an excellent near-infrared light absorption through a refined molecular strategy.Meanwhile,Nc PB was assembled into nanoparticles with different sizes(Nano Nc PB-1 and Nano Nc PB-0)by a supramolecular modulation strategy.As the results,the nanoparticle with an ultra-small size(Nano Nc PB-1)generated a large number of superoxide anion(O_(2)^(·-))in a low-O_(2)-dependent manner and release plenty of heat.Furthermore,the results of in vivo experiments demonstrated that Nano Nc PB-1 actively accumulated in tumor tissues and showed a 92%tumor inhibition after photodynamic and photothermal combination therapy.More importantly,Nano Nc PB-1 could be rapidly cleared from the body of mice via the renal pathway,which alleviates potential side effects of prolonged retention of PS in the circulation.展开更多
Combining practical engineering projects, this article analyzes the design strategies for the reconstruction and expansion of insufficient clearance sections in highway interchanges. This includes an overview of the p...Combining practical engineering projects, this article analyzes the design strategies for the reconstruction and expansion of insufficient clearance sections in highway interchanges. This includes an overview of the project, a comparison of design options for insufficient clearance in interchanges, and the main design strategies for reconstruction and expansion. It is hoped that this analysis can provide a reference for the design of such road reconstruction and expansion projects.展开更多
BACKGROUND Chronic hepatitis B(CHB)patients rarely achieve functional cure with initial pegylated interferon alpha-2b(Peg-IFNα-2b)therapy.Validated tools to guide retreatment candidates are lacking.We hypothesized th...BACKGROUND Chronic hepatitis B(CHB)patients rarely achieve functional cure with initial pegylated interferon alpha-2b(Peg-IFNα-2b)therapy.Validated tools to guide retreatment candidates are lacking.We hypothesized that clinical indicators predict hepatitis B surface antigen(HBsAg)clearance during retreatment.AIM To develop a prediction model for HBsAg clearance in Peg-IFNα-2b retreatment.METHODS In this retrospective cohort study,we enrolled 135 CHB/compensated cirrhosis patients receiving Peg-IFNα-2b retreatment after initial non-clearance at Tianjin University Central Hospital(2017-2025).Predictors were identified through univariate Cox,least absolute shrinkage and selection operator,and multivariate Cox regression.Model performance was assessed via receiver operating characteristic analysis and Harrell’s C-index,with risk stratification by X-tile optimization.RESULTS HBsAg clearance rate was 20.74%(28/135).Independent predictors included:Combination nucleos(t)ide analogue(NA)therapy during initial treatment[hazard ratio(HR)=0.276,95%confidence interval(CI):0.092-0.833],baseline HBsAg at retreatment(HR=0.571,95%CI:0.410-0.795),HBsAg decline after initial treatment(HR=2.050,95%CI:1.108-3.793),and treatment interval(HR=1.013/week,95%CI:1.008-1.018).The retreatment HBsAg clearance prediction score(RHCP-S)demonstrated area under the curve of 0.920(95%CI:0.863-0.946),sensitivity of 92.3%,specificity of 79.3%.Clearance rates differed significantly:RHCP-S challenge group(≤74 points):3.45%,RHCP-S probable group(74-110 points):29.63%,RHCP-S dominant group(≥110 points):80.95%(P<0.001).CONCLUSION The overall HBsAg clearance rate with Peg-IFNα-2b retreatment was 20.74%(28/135).The RHCP-S model identifies optimal retreatment candidates(≥110 points)with 80.95%clearance probability,associated with the absence of combination NA therapy during initial treatment,greater initial HBsAg decline,longer intervals,and lower retreatment HBsAg.展开更多
Mechanical vibration sputum clearance is commonly used for airway clearance.However,existing handheld vibration-assisted expectorators confront several challenges including operator’s hand fatigue and a high risk of ...Mechanical vibration sputum clearance is commonly used for airway clearance.However,existing handheld vibration-assisted expectorators confront several challenges including operator’s hand fatigue and a high risk of cross-infection between medical staff and patients.To address these issues,this study presents a novel design for an intelligent percussion-based sputum clearance robot.The robot is designed to assist medical staff in providing percussion-based sputum clearance nursing for patients.Initially,the structure of the robot is designed based on the environmental conditions in the intensive care unit(ICU).To mitigate the impact of the vibrations generated by the vibration percussion head on the robotic arm operation,a fixture equipped with a vibration damper is designed to ensure that the robot’s standard functionality remains unaffected.Furthermore,a human back detection(HBD)framework constructed from multi-subtask modules is proposed to address the shortcomings of existing robotic systems in terms of human perception capabilities.These modules are designed to accurately identify and map the anatomical features of the human back.This effectively improves the capability of the robot to interact with the human body.Based on this framework,the robotic arm is controlled precisely to emulate the percussion strategies employed by physicians.Finally,extensive experiments are conducted in a real-world setting with multiple participants.The results indicate that the robot could provide percussion-based sputum clearance nursing that is practically equivalent to the operations by medical staff.展开更多
The existence of the aeroengine casing,limited monitoring points,and multi-fault characteristics make obtaining the rotor’s vibration transmission characteristics challenging,resulting in difficulties accurately iden...The existence of the aeroengine casing,limited monitoring points,and multi-fault characteristics make obtaining the rotor’s vibration transmission characteristics challenging,resulting in difficulties accurately identifying the rotor unbalance.This paper utilizes a high-frequency composite sensor to monitor the engine’s blade tip clearance(BTC)and extracts unbalanced information from BTC signals for rotor dynamic balancing,while avoiding the need for the once per revolution(OPR)sensor.First,the vibration characteristics of the rotor-blade system under multi-fault conditions are investigated.Then,based on BTC measurement,a none OPR method and an unbalance identification method are proposed,in which the radial vibration of the blade tip in the BTC signals at different speeds is extracted and operated in the time domain to obtain the rotor unbalanced vibration,the signal is reconstructed,and cross-correlation analysis is used to accurately identify the magnitude and phase of the unbalanced signal.Finally,a rotor test bench is utilized for experimental verification.The results reveal that the dynamic balancing method based on the BTC signal can more precisely identify the rotor unbalance than the traditional rotor dynamic balancing method.The application of this technique will effectively improve engine health management and fault prediction.展开更多
As the performance of the box-type multiple launch rocket system(BMLRS)improves,its mechanical structures,particularly the plane clearance design between the slider on the rocket and the guide inside the launch canist...As the performance of the box-type multiple launch rocket system(BMLRS)improves,its mechanical structures,particularly the plane clearance design between the slider on the rocket and the guide inside the launch canister,have grown increasingly complex.However,deficiencies still exist in the current launch modeling theory for BMLRS.In this study,a multi-rigid-flexible-body launch dynamics model coupling the launch platform and rocket was established using the multibody system transfer matrix method and the Newton-Euler formulation.Furthermore,considering the bending of the launch canister,a detection algorithm for slider-guide plane clearance contact was proposed.To quantify the contact force and friction effect between the slider and guide,the contact force model and modified Coulomb model were introduced.Both the modal and launch tests were conducted.Additionally,the modal convergence was verified.By comparing the modal experiments and simulation results,the maximum relative error of the eigenfrequency is 3.29%.thereby verifying the accuracy of the developed BMLRS dynamics model.Furthermore,the launch test validated the proposed plane clearance contact model.Moreover,the study investigated the influence of various model parameters on the dynamic characteristics of BMLRS,including launch canister bending stiffness,slider and guide material,slider-guide clearance,slider length and layout.This analysis of influencing factors provides a foundation for future optimization in BMLRS design.展开更多
基金supported by the National Natural Science Foundation of China,No.81971031(to ZL)the National Key Research and Development Program of China,No.2022YFE0210100(to JFC)+7 种基金the National Natural Science Foundation of China(Original Exploration Project),No.82151308(to JFC)the National Natural Science Foundation of China(Research Fund for International Senior Scientists),No.82150710558(to JFC)Science&Technology Initiative STI2030-Major Projects,No.2021ZD0203400(to JFC)Key Research and Development Program of Zhejiang Province,No.2023C03079(to JFC)Scientific Research Starting Foundation of Oujiang Laboratory(Zhejiang Laboratory for Regenerative Medicine,Vision and Brain Health),No.OJQDSP2022007(to JFC)Project of State Key Laboratory of Ophthalmology,Optometry and Visual Science,Wenzhou Medical University,No.J01-20190101(to JFC)Scientific Research Starting Foundation of Wenzhou Medical University,No.QTJ12003(to JFC)Department of Science and Technology of Zhejiang Province,No.2023ZY1011(to JFC)。
文摘The excessive buildup of neurotoxicα-synuclein plays a pivotal role in the pathogenesis of Parkinson's disease,highlighting the urgent need for innovative therapeutic strategies to promoteα-synuclein clearance,particularly given the current lack of disease-modifying treatments.The glymphatic system,a recently identified perivascular fluid transport network,is crucial for clearing neurotoxic proteins.This review aims to synthesize current knowledge on the role of the glymphatic system inα-synuclein clearance and its implications for the pathology of Parkinson's disease while emphasizing potential therapeutic strategies and areas for future research.The review begins with an overview of the glymphatic system and details its anatomical structure and physiological functions that facilitate cerebrospinal fluid circulation and waste clearance.It summarizes emerging evidence from neuroimaging and experimental studies that highlight the close correlation between the glymphatic system and clinical symptom severity in patients with Parkinson's disease,as well as the effect of glymphatic dysfunction onα-synuclein accumulation in Parkinson's disease models.Subsequently,the review summarizes the mechanisms of glymphatic system impairment in Parkinson's disease,including sleep disturbances,aquaporin-4 impairment,and mitochondrial dysfunction,all of which diminish glymphatic system efficiency.This creates a vicious cycle that exacerbatesα-synuclein accumulation and worsens Parkinson's disease.The therapeutic perspectives section outlines strategies for enhancing glymphatic activity,such as improving sleep quality and pharmacologically targeting aquaporin-4 or its subcellular localization.Promising interventions include deep brain stimulation,melatonin supplementation,γ-aminobutyric acid modulation,and non-invasive methods(such as exercise and bright-light therapy),multisensoryγstimulation,and ultrasound therapy.Moreover,identifying neuroimaging biomarkers to assess glymphatic flow as an indicator ofα-synuclein burden could refine Parkinson's disease diagnosis and track disease progression.In conclusion,the review highlights the critical role of the glymphatic system inα-synuclein clearance and its potential as a therapeutic target in Parkinson's disease.It advocates for further research to elucidate the specific mechanisms by which the glymphatic system clears misfoldedα-synuclein and the development of imaging biomarkers to monitor glymphatic activity in patients with Parkinson's disease.Findings from this review suggest that enhancing glymphatic clearance is a promising strategy for reducingα-synuclein deposits and mitigating the progression of Parkinson's disease.
基金Supported by National Natural Science Foundation of China(Grant Nos.51635002(Key Program),51605011,51275015)
文摘Joint clearances in antenna pointing mechanisms lead to uncertainty in function deviation. Current studies mainly focus on radial clearance of revolute joints, while axial clearance has rarely been taken into consideration. In fact, own?ing to errors from machining and assembly, thermal deformation and so forth, practically, axial clearance is inevitable in the joint. In this study, an error equivalent model(EEM) of revolute joints is proposed with considering both radial and axial clearances. Compared to the planar model of revolute joints only considering radial clearance, the journal motion inside the bearing is more abundant and matches the reality better in the EEM. The model is also extended for analyzing the error distribution of a spatial dual?axis("X–Y" type) antenna pointing mechanism of Spot?beam antennas which especially demand a high pointing accuracy. Three case studies are performed which illustrates the internal relation between radial clearance and axial clearance. It is found that when the axial clearance is big enough, the physical journal can freely realize both translational motion and rotational motion. While if the axial clearance is limited, the motion of the physical journal will be restricted. Analysis results indicate that the consideration of both radial and axial clearances in the revolute joint describes the journal motion inside the bearing more precise. To further validate the proposed model, a model of the EEM is designed and fabricated. Some suggestions on the design of revolute joints are also provided.
基金Supported by National Natural Science Foundation of China(Grant Nos.51205121,51375162)Scientific Research Foundation of Hunan Provincial Education Department of China(Grant No.13A023)Postgraduate Innovation Foundation of Hunan University of Science and Technology,China(Grant No.S140020)
文摘The inner and outer oil film dynamic characteristic coefficients of floating ring bearings（FRBs） change due to the manufacturing tolerance of the floating ring, journal and intermediate, which leads to high-speed turbocharger＇s vibration too large and even causes nonlinear vibration accident. However, the investigation of floating ring bearing manufacturing tolerance clearance on the rotordynamic characteristics is less at present. In order to study the influence law of inner and outer clearance on turbocharger vibration, the rotor dynamic motion equations of turbocharger supported in FRBs are derived by analyzing the size relations between floating ring, journal and intermediate for the inner and outer oil film clearances, the time transient response analysis for combination of FRBs clearance are developed. A realistic turbocharger is taken as a research object, the FE model of the turbocharger with FRBs is modeled. Under the conditions of four kinds of limit state bearing clearances for inner and outer oil film, the nonlinear transient analyses are performed based on the established FE dynamic models of the nonlinear rotor-FRBs system applied incentive combinations of gravity and unbalance force, respectively. From the waterfall, the simulation results show that the speed for the appearance of fractional frequency is not identical and the amplitude magnitude is different under the four kinds of bearing manufacturing tolerance limit clearances, and fractional frequency does not appear in the turbocharger and the amplitude is minimum under the ODMin/IDMax bearing manufacturing tolerance clearances. The turbocharger vibration is reduced by controlling the manufacturing tolerance clearance combinations of FRBs, which is helpful for the dynamic design and production-manufacturing of high-speed turbocharger.
文摘This paper uses the topology theory to analyze the surface flowspectrums of straight, positively curved and negatively curvedcascades with relative tip clearances of 0.023 and 0.036, findsapparent differences of topology and vortex structures in the bladetip and the suction side wall corner of single type of cascade withthis two clearances, and studies the mechanism of the differenceformation as well as their effects o the energy loss.
基金co-supported by the Natural Science Foundation of Hebei Province of China(No.E2017402135)the Program of Science and Technology Research and Development of Handan of China(No.1621212047-2)
文摘It has been well known that nozzle end-clearances in a Variable Nozzle Turbine（VNT）are unfavorable for aerodynamic performance, especially at small openings, and efforts to further decrease size of the clearances are very hard due to thermal expansion. In this paper, both the different sizes of nozzle end-clearances and the various ratios of their distribution at the hub and shroud sides were modelled and investigated by performing 3D Computational Fluid Dynamics（CFD） and Finite Element Analysis（FEA） simulations with a code of transferring the aerodynamic pressure from the CFD results to the FEA calculations. It was found that increasing the size of the nozzle end-clearances divided equally at the hub and shroud sides deteriorates turbine efficiency and turbine wheel reliability, yet increases turbine flow capacity. And, when the total nozzle endclearances remain the same, varying nozzle end-clearances＇ distribution at the hub and shroud sides not only shifts operation point of a VNT turbine, but also affects the turbine wheel vibration stress.Compared with nozzle hub clearance, the shroud clearance is more sensitive to both aerodynamic performance and reliability of a VNT turbine. Consequently, a possibility is put forward to improve VNT turbine efficiency meanwhile decrease vibration stress by optimizing nozzle end-clearances＇ distribution.
基金supported by the National Basic Research Program of China(No.613321)。
文摘To investigate the effect of tip clearance size on cavitation characteristics in a turbopump inducer,a series of experiments have been conducted in a newly developed visualization test facility using room temperature water as working fluid.The pressure fluctuations near the tip region were collected,and the cavity structures under various conditions were documented by a high-speed camera.It is found that large tip clearance distinctly reduces both the non-cavitation and cavitation performance.Three cavitation instabilities,super-synchronous rotating cavitation,synchronous rotating cavitation and cavitation surge have been carefully identified through combination of cross-correlation analysis of pressure signals and visualization results.Large tip clearance displays a remarkable stabilization effect on pressure fluctuation,cavitation surge totally disappears,and the range of occurrence of synchronous rotating cavitation becomes smaller for the large tip clearance,whereas super-synchronous rotating cavitation only occurs in the large tip clearance.The cavitation areas are smaller at large tip clearance,while the flow channels are more seriously choked when cavitation occurs heavily in comparison with those at small tip clearance,which may be responsible for the worse cavitation performance.
基金The project supported by the National Natural Science Foundation of China(10272002:60334030)
文摘This paper is concerned with the determination of the normal force-displacement （NFD） relation for the contact problem of cylindrical joints with clearance. A simple formulation for this contact problem is developed by modeling the pin as a rigid wedge and the elastic plate as a simple Winkler elastic foundation. The numerical results show that the normal displacement relation based on Hertz theory is only valid for the case of large clearance with a small normal load, and the NFD relation based on Persson theory is only effective in the case of very small clearance. The proposed approximate model in this paper gives better results than Hertz theory and Persson theory in a large range of clearances as seen from the comparison with the results of FEM.
基金Projects(51375226,51305196,51475226) supported by the National Natural Science Foundation of ChinaProjects(NZ2013303,NZ2014201) supported by the Fundamental Research Funds for the Central Universities,China
文摘A new non-linear transverse-torsional coupled model was proposed for 2K-H planetary gear train, and gear's geometric eccentricity error, comprehensive transmission error, time-varying meshing stiffness, sun-planet and planet-ring gear pair's backlashes and sun gear's bearing clearance were taken into consideration. The solution of differential governing equation of motion was solved by applying variable step-size Runge-Kutta numerical integration method. The system motion state was investigated systematically and qualitatively, and exhibited diverse characteristics of bifurcation and chaos as well as non-linear behavior under different bifurcation parameters including meshing frequency, sun-planet backlash, planet-ring backlash and sun gear's bearing clearance. Analysis results show that the increasing damping could suppress the region of chaotic motion and improve the system's stability significantly. The route of crisis to chaotic motion was observed under the bifurcation parameter of meshing frequency. However, the routes of period doubling and crisis to chaos were identified under the bifurcation parameter of sun-planet backlash; besides, several different types of routes to chaos were observed and coexisted under the bifurcation parameter of planet-ring backlash including period doubling, Hopf bifurcation, 3T-periodic channel and crisis. Additionally, planet-ring backlash generated a strong coupling effect to system's non-linear behavior while the sun gear's bearing clearance produced weak coupling effect. Finally, quasi-periodic motion could be found under all above–mentioned bifurcation parameters and closely associated with the 3T-periodic motion.
基金Project(51105194)supported by the National Natural Science Foundation of ChinaProject(20113218110017)supported by the Doctoral Program Foundation of Institutions of Higher Education of China+2 种基金Project supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions,ChinaProject(CXZZ11_0199)supported by the Funding of Jiangsu Innovation Program for Graduate Education,ChinaProjects(NZ2013303,NZ2014201)supported by the Fundamental Research Funds for the Central Universities,China
文摘A new nonlinear transverse-torsional coupled model with backlash and bearing clearance was proposed for planetary gear set. Meanwhile, sun gear and planet's eccentricity errors, static transmission error, and time-varying meshing stiffness were taken into consideration. The differential governing equations of motion were solved by employing variable step-size Rung-Kutta numerical integration method. The behavior of dynamic load sharing characteristics affected by the system parameters including input rate, sun gear's supporting stiffness and eccentricity error, planet's eccentricity error, sun gear's bearing clearance, backlashes of sun-planet and planet-ring meshes were investigated qualitatively and systematically. Some theoretical results are summarized at last which extend the current understanding of the dynamic load sharing behavior of planet gear train, enrich the related literature and provide references for the design of planetary gear train.
文摘This article reports on track-monitoring and analyzing machine clearances during wood forwarding across seasons and weather, using ultrasonic distance sensors in combination with time-stamped GPS xy locations, at 10 sec intervals. The resulting data, obtained from 54 harvesting blocks, were analyzed by machine type (two wood forwarders and one grapple skidder), stand type (softwood plantation versus natural hardwood stands), month, slope, cartographic depth-to-water (DTW) classes, number of passes along track, and machine speed. For the most part, clearances were highly variable, due to passing over stumps, rocks, harvest slash, brushmats, ruts, and snow cover when present. This variability was on average greater for the lighter-weight wood forwarders than for the heavier-weight skidder, with the former mostly moving along equally spaced lines on brushmats, while the paths of the latter spread away from central wood-landing sites. In terms of trends, machines moved 1) more slowly on wet ground, 2) faster during returning than forwarding, and 3) fastest along wood-landing roads, as to be expected. Low clearances were most notable during winter on snow-covered ground, and on non-frozen shallow DTW and wet multiple-pass ground. During dry weather conditions, clearances also increased from low-pass tracks to multi-pass tracks due to repeat soil compaction of broadened tracks. These results are presented block-by-block and by machine type. Each block-based clearance frequency pattern was quantified through regression analysis and using a gamma probability distribution function.
基金Sponsored by the Shandong Key Research and Development Public Welfare Program(Grant No.2019GGX104011)the Natural Science Foundation of Shandong Province(Grant No.ZR2017MEE066).
文摘There are clearances in mechanism because of manufacture and assembly error,which reduces operation life and working accuracy of mechanism and has a great impact on dynamical responses.At the moment,research in this area mainly focuses on single degree⁃of⁃freedom mechanism considering one clearance,while research of multi⁃DOF mechanism considering multi⁃clearance is less.With the purpose of studying the dynamical characteristics of complex multi⁃DOF mechanism with multi⁃clearances,a dynamic model was developed.The dynamic responses of 2⁃DOF mechanism with two clearances under different positions,values,and numbers of clearance were analyzed.The displacement,velocity,acceleration,collision force,and the axis trajectory at clearance were then given.In addition,there is a limited amount of literature on chaotic phenomena,which mainly focuses on the chaotic phenomena of end⁃effector of mechanism.But in this paper,the non⁃linear characteristics were analyzed by chaotic phenomenon of clearance joint,then chaotic phenomenon was identified by Poincarémappings and phase diagrams.Bifurcation diagrams were given.The results will offer a reliable technical support for the study of dynamical responses of planar mechanisms and the analysis of chaotic phenomena.
基金financially supported by the Science and Technology Innovation Program of Hunan Province,No.2022RC1220(to WP)China Postdoctoral Science Foundation,No.2022M711733(to ZZ)+2 种基金the National Natural Science Foundation of China,No.82160920(to ZZ)Hebei Postdoctoral Scientific Research Project,No.B2022003040(to ZZ)Hunan Flagship Department of Integrated Traditional Chinese and Western Medicine(to WP)。
文摘Alzheimer's disease,the primary cause of dementia,is characterized by neuropathologies,such as amyloid plaques,synaptic and neuronal degeneration,and neurofibrillary tangles.Although amyloid plaques are the primary characteristic of Alzheimer's disease in the central nervous system and peripheral organs,targeting amyloid-beta clearance in the central nervous system has shown limited clinical efficacy in Alzheimer's disease treatment.Metabolic abnormalities are commonly observed in patients with Alzheimer's disease.The liver is the primary peripheral organ involved in amyloid-beta metabolism,playing a crucial role in the pathophysiology of Alzheimer's disease.Notably,impaired cholesterol metabolism in the liver may exacerbate the development of Alzheimer's disease.In this review,we explore the underlying causes of Alzheimer's disease and elucidate the role of the liver in amyloid-beta clearance and cholesterol metabolism.Furthermore,we propose that restoring normal cholesterol metabolism in the liver could represent a promising therapeutic strategy for addressing Alzheimer's disease.
文摘Metamorphic mechanism has the advantages of variable topology and variable degrees of freedom, which can realize the requirements of multi-conditions and multi-tasks, and has a good application prospect. The configuration transformation is prominent feature of the metamorphic mechanism. The number of constraints or properties of the kinematic pairs provided by the metamorphic kinematic pairs will change under certain conditions, its dynamic performance is much more complex than that of traditional kinematic pairs with immutable constraints. However, the clearance model about traditional kinematic pairs with immutable constraints established by long-term research is difficult to be directly applied to the metachromatic kinematic pairs. Referring to the experience of the traditional kinematic pairs with immutable constraints, the continuous contact model of Metamorphic Groove pin pair with clearance is established. According to the traditional continuous contact model of the kinematic pairs with immutable constraints, the forces between the elements of kinematic pair of the mechanism with clearance and the ideal mechanism without clearance are regarded as the same, and the inertia force and inertia moment of the components are also calculated according to the acceleration of the ideal mechanism. The clearance is regarded as a massless virtual bar with length r. For the rotating pair part, the massless virtual bar length r is the difference between the radius of the shaft and the hole, and for the sliding pair part, the massless virtual bar length r is half of the difference between the height of the slider and the guide groove. According to the new mechanism without gap after adding the imaginary bar, kinetic energy and potential energy of the system are calculated for the two configurations of mechanism with metamorphic Groove pin pair with clearance. The kinetic energy and potential energy of the system are calculated according to the new mechanism without clearance after adding the massless virtual bar. The kinetic energy, potential energy and generalized force are substituted into the Lagrangian equation to obtain the motion equation of the metamorphic mechanism, which lays the foundation for the dynamic performance study of the mechanism with metamorphic groove pin pair with clearance.
基金the National Natural Science Foundation of China(Nos.T2322004 and 22078066)。
文摘Currently,it is still a challenge to develop an organic photosensitizer(PS)with outstanding near-infrared absorption,low O2dependence,precise tumor targeting and rapid clearance through the kidney to improve the overall outcome of phototherapy.In this study,we have designed an organic PS(Nc PB)with an excellent near-infrared light absorption through a refined molecular strategy.Meanwhile,Nc PB was assembled into nanoparticles with different sizes(Nano Nc PB-1 and Nano Nc PB-0)by a supramolecular modulation strategy.As the results,the nanoparticle with an ultra-small size(Nano Nc PB-1)generated a large number of superoxide anion(O_(2)^(·-))in a low-O_(2)-dependent manner and release plenty of heat.Furthermore,the results of in vivo experiments demonstrated that Nano Nc PB-1 actively accumulated in tumor tissues and showed a 92%tumor inhibition after photodynamic and photothermal combination therapy.More importantly,Nano Nc PB-1 could be rapidly cleared from the body of mice via the renal pathway,which alleviates potential side effects of prolonged retention of PS in the circulation.
文摘Combining practical engineering projects, this article analyzes the design strategies for the reconstruction and expansion of insufficient clearance sections in highway interchanges. This includes an overview of the project, a comparison of design options for insufficient clearance in interchanges, and the main design strategies for reconstruction and expansion. It is hoped that this analysis can provide a reference for the design of such road reconstruction and expansion projects.
基金Supported by the Tianjin Health Research Project(Key Project),No.TJWJ2024ZD004Tianjin Key Medical Discipline(Specialty)Construction Project,No.TJYXZDXK-034A.
文摘BACKGROUND Chronic hepatitis B(CHB)patients rarely achieve functional cure with initial pegylated interferon alpha-2b(Peg-IFNα-2b)therapy.Validated tools to guide retreatment candidates are lacking.We hypothesized that clinical indicators predict hepatitis B surface antigen(HBsAg)clearance during retreatment.AIM To develop a prediction model for HBsAg clearance in Peg-IFNα-2b retreatment.METHODS In this retrospective cohort study,we enrolled 135 CHB/compensated cirrhosis patients receiving Peg-IFNα-2b retreatment after initial non-clearance at Tianjin University Central Hospital(2017-2025).Predictors were identified through univariate Cox,least absolute shrinkage and selection operator,and multivariate Cox regression.Model performance was assessed via receiver operating characteristic analysis and Harrell’s C-index,with risk stratification by X-tile optimization.RESULTS HBsAg clearance rate was 20.74%(28/135).Independent predictors included:Combination nucleos(t)ide analogue(NA)therapy during initial treatment[hazard ratio(HR)=0.276,95%confidence interval(CI):0.092-0.833],baseline HBsAg at retreatment(HR=0.571,95%CI:0.410-0.795),HBsAg decline after initial treatment(HR=2.050,95%CI:1.108-3.793),and treatment interval(HR=1.013/week,95%CI:1.008-1.018).The retreatment HBsAg clearance prediction score(RHCP-S)demonstrated area under the curve of 0.920(95%CI:0.863-0.946),sensitivity of 92.3%,specificity of 79.3%.Clearance rates differed significantly:RHCP-S challenge group(≤74 points):3.45%,RHCP-S probable group(74-110 points):29.63%,RHCP-S dominant group(≥110 points):80.95%(P<0.001).CONCLUSION The overall HBsAg clearance rate with Peg-IFNα-2b retreatment was 20.74%(28/135).The RHCP-S model identifies optimal retreatment candidates(≥110 points)with 80.95%clearance probability,associated with the absence of combination NA therapy during initial treatment,greater initial HBsAg decline,longer intervals,and lower retreatment HBsAg.
基金Supported by National Key R&D Program of China(Grant No.2021YFC0122700).
文摘Mechanical vibration sputum clearance is commonly used for airway clearance.However,existing handheld vibration-assisted expectorators confront several challenges including operator’s hand fatigue and a high risk of cross-infection between medical staff and patients.To address these issues,this study presents a novel design for an intelligent percussion-based sputum clearance robot.The robot is designed to assist medical staff in providing percussion-based sputum clearance nursing for patients.Initially,the structure of the robot is designed based on the environmental conditions in the intensive care unit(ICU).To mitigate the impact of the vibrations generated by the vibration percussion head on the robotic arm operation,a fixture equipped with a vibration damper is designed to ensure that the robot’s standard functionality remains unaffected.Furthermore,a human back detection(HBD)framework constructed from multi-subtask modules is proposed to address the shortcomings of existing robotic systems in terms of human perception capabilities.These modules are designed to accurately identify and map the anatomical features of the human back.This effectively improves the capability of the robot to interact with the human body.Based on this framework,the robotic arm is controlled precisely to emulate the percussion strategies employed by physicians.Finally,extensive experiments are conducted in a real-world setting with multiple participants.The results indicate that the robot could provide percussion-based sputum clearance nursing that is practically equivalent to the operations by medical staff.
基金supported by the Key Program of National Natural Science Foundation of China(No.92160203)National Natural Science Foundation of China(No.92360306).
文摘The existence of the aeroengine casing,limited monitoring points,and multi-fault characteristics make obtaining the rotor’s vibration transmission characteristics challenging,resulting in difficulties accurately identifying the rotor unbalance.This paper utilizes a high-frequency composite sensor to monitor the engine’s blade tip clearance(BTC)and extracts unbalanced information from BTC signals for rotor dynamic balancing,while avoiding the need for the once per revolution(OPR)sensor.First,the vibration characteristics of the rotor-blade system under multi-fault conditions are investigated.Then,based on BTC measurement,a none OPR method and an unbalance identification method are proposed,in which the radial vibration of the blade tip in the BTC signals at different speeds is extracted and operated in the time domain to obtain the rotor unbalanced vibration,the signal is reconstructed,and cross-correlation analysis is used to accurately identify the magnitude and phase of the unbalanced signal.Finally,a rotor test bench is utilized for experimental verification.The results reveal that the dynamic balancing method based on the BTC signal can more precisely identify the rotor unbalance than the traditional rotor dynamic balancing method.The application of this technique will effectively improve engine health management and fault prediction.
基金supported by National Natural Science Foundation of China(Grant No.92266201).
文摘As the performance of the box-type multiple launch rocket system(BMLRS)improves,its mechanical structures,particularly the plane clearance design between the slider on the rocket and the guide inside the launch canister,have grown increasingly complex.However,deficiencies still exist in the current launch modeling theory for BMLRS.In this study,a multi-rigid-flexible-body launch dynamics model coupling the launch platform and rocket was established using the multibody system transfer matrix method and the Newton-Euler formulation.Furthermore,considering the bending of the launch canister,a detection algorithm for slider-guide plane clearance contact was proposed.To quantify the contact force and friction effect between the slider and guide,the contact force model and modified Coulomb model were introduced.Both the modal and launch tests were conducted.Additionally,the modal convergence was verified.By comparing the modal experiments and simulation results,the maximum relative error of the eigenfrequency is 3.29%.thereby verifying the accuracy of the developed BMLRS dynamics model.Furthermore,the launch test validated the proposed plane clearance contact model.Moreover,the study investigated the influence of various model parameters on the dynamic characteristics of BMLRS,including launch canister bending stiffness,slider and guide material,slider-guide clearance,slider length and layout.This analysis of influencing factors provides a foundation for future optimization in BMLRS design.
