Ownership is an increasingly important conflict in outer space at this moment in time.Despite the principle in the Outer Space Treaty(1967),that emphasizes the importance of all states'free access to outer space b...Ownership is an increasingly important conflict in outer space at this moment in time.Despite the principle in the Outer Space Treaty(1967),that emphasizes the importance of all states'free access to outer space based on equality for exploration and use.Moreover,outer space including the Moon and other celestial bodies is not subject to national appropriation by claim of sovereignty,by means of use or occupation,or by any other means.However,outer space activity is not free from sovereignty and jurisdiction after all.Anyway,the legal situation relating to space resource exploitation and utilization activities under the adoption of United Nations is a challenge.Some scholars implied that the Outer Space Treaty(1967)clearly prohibits appropriation of whole celestial bodies but is far less clear concerning the rights of over-extracted resources.Nevertheless,the Moon Agreement(1979)promotes the idea of property ownership of over-extracted resources.It permits states to collect and remove samples of lunar minerals and other substances for further interest in scientific investigation.The application of the Moon Agreement(1979)is not only to the Moon itself but to other celestial bodies,thus potentially covering the planets and asteroids where the mining potential is considered to be limitless.Under this circumstance,numerous countries,such as the United States,Luxembourg,The United Arab Emirates,and Japan have enacted legal regimes that glorify the rights of their entities in mineral resources in outer space.However,these regimes could be disputed under the international legal framework if countries have merely interpreted and applied their rights and obligations on a national level as they understand them.Therefore,this paper purports to clarify the ownership rights in outer space and analyze the purpose of the legal situation relating to space resource exploitation and utilization activities under the adoption of the United States,Luxembourg,The United Arab Emirates,and Japan.展开更多
A microgravity environment has been shown to cause ocular damage and affect visual acuity,but the underlying mechanisms remain unclear.Therefore,we established an animal model of weightlessness via tail suspension to ...A microgravity environment has been shown to cause ocular damage and affect visual acuity,but the underlying mechanisms remain unclear.Therefore,we established an animal model of weightlessness via tail suspension to examine the pathological changes and molecular mechanisms of retinal damage under microgravity.After 4 weeks of tail suspension,there were no notable alterations in retinal function and morphology,while after 8 weeks of tail suspension,significant reductions in retinal function were observed,and the outer nuclear layer was thinner,with abundant apoptotic cells.To investigate the mechanism underlying the degenerative changes that occurred in the outer nuclear layer of the retina,proteomics was used to analyze differentially expressed proteins in rat retinas after 8 weeks of tail suspension.The results showed that the expression levels of fibroblast growth factor 2(also known as basic fibroblast growth factor)and glial fibrillary acidic protein,which are closely related to Müller cell activation,were significantly upregulated.In addition,Müller cell regeneration and Müller cell gliosis were observed after 4 and 8 weeks,respectively,of simulated weightlessness.These findings indicate that Müller cells play an important regulatory role in retinal outer nuclear layer degeneration during weightlessness.展开更多
AIM:To comprehensively examine the clinical presentations,multimodal images,and long-term follow-up of Chinese patients with acute zonal occult outer retinopathy(AZOOR),a rare inflammatory disorder.METHODS:This was a ...AIM:To comprehensively examine the clinical presentations,multimodal images,and long-term follow-up of Chinese patients with acute zonal occult outer retinopathy(AZOOR),a rare inflammatory disorder.METHODS:This was a retrospective study.A total of 20 patients(32 eyes)were included.The medical records and multimodal imaging,including wide-field fundus photography,wide-field fundus autofluorescence(FAF),and swept-source optical coherence tomography(SS-OCT)were analyzed.RESULTS:The study included 20 patients with a mean age of 38.2±10.9y,and females accounted for 60%.Lesions could involve peripapillary areas,macular region,and peripheral retina.The mean best-corrected visual acuity(BCVA)at presentation was 0.38±0.60 logMAR,with no significant difference in visual acuity between acute cases(within 6mo of onset)and chronic cases(beyond 6mo of onset;P=0.390).There was no statistically significant difference in visual acuity between eyes of acute case(within 6mo of onset)and the chronic case(beyond 6mo of onset).In some chronic case,FAF examination revealed the presence of a hyperautofluorescent(hyperAF)ring around the macular area(6/18),a phenomenon not observed in the acute case(P=0.024).A higher proportion of chronic cases showed predominantly hypoautofluorescent(hypoAF)lesions compared to the acute case(13/18 vs 2/14,P=0.0016).SS-OCT examination showed that both acute and chronic cases exhibited hyperreflective dots above the retinal pigment epithelium(RPE),and ellipsoid zone(EZ)and RPE damage.In the chronic case,eyes with hyperreflective dots above the RPE were more likely to exhibit EZ and RPE damage in the macular region compared to those without these dots.CONCLUSION:Multimodal imaging plays a crucial role in the follow-up of patients with AZOOR.In chronic cases of AZOOR,the presence of hyperreflective dots above the RPE indicates a higher likelihood of outer retinal involvement in the macular region.This study provides critical insights into the complex presentation and progression of AZOOR.展开更多
Objectives Retinal ischemia-reperfusion(RIR)injury results in irreversible visual impairments.The disruption of the outer blood-retinal barrier(OBRB)is a major ocular pathogenic process that RIR injury affects.Current...Objectives Retinal ischemia-reperfusion(RIR)injury results in irreversible visual impairments.The disruption of the outer blood-retinal barrier(OBRB)is a major ocular pathogenic process that RIR injury affects.Current clinical strategies are limited.This study aimed to elucidate how electroacupuncture(EA)protects the OBRB against RIR injury.Methods Male Wistar rats(7 weeks old,250 g to 280 g)were used in this study.Three independent experiments were conducted.First,Opioid peptide levels were quantified using enzyme-linked immunosorbent assay(ELISA).42 rats were randomly divided into 7 groups(n=6/group):Control:No treatment;high intraocular pressure(HIOP):Acute intraocular pressure elevation-induced RIR injury;HIOP+SHAM EA:RIR injury+sham EA at Xinming(Extra acupoint)and Jingming(BL1)for 30 min(shallow needle insertion but without electric stimulation);HIOP+2 Hz EA:RIR injury+2 Hz EA at Xinming and BL1 for 30 min;HIOP+100 Hz:RIR injury+100 Hz EA at Xinming and BL1 for 30 min;HIOP+2/100 Hz EA:RIR injury+2/100 Hz EA at Xinming and BL1 for 30 min;HIOP+4/20 Hz EA:RIR injury+4/20 Hz EA at Xinming and BL1 for 30 min.Second,retinal morphology was assessed by hematoxylin and eosin(HE)staining.20 rats were randomly allocated into 4 groups(n=5/group):Control:No treatment;HIOP:Acute intraocular pressure elevation-induced RIR injury;HIOP+SHAM EA:RIR injury+sham EA at Xinming and BL1 for 30 min(shallow needle insertion but without electric stimulation);HIOP+2 Hz EA:RIR injury+2 Hz EA at Xinming and BL1 for 30 min.Third,the permeability of OBRB was evaluated using the fluorescein isothiocyanate(FITC)-dextran leakage assay.15 rats were randomly divided into 5 groups(n=3/group):Control:No treatment;HIOP:Acute intraocular pressure elevation-induced RIR injury;HIOP+SHAM EA:RIR injury+sham EA at Xinming and BL1 for 30 min(shallow needle insertion but without electric stimulation);HIOP+2 Hz EA:RIR injury+2 Hz EA at Xinming and BL1 for 30 min;Nal+HIOP+2 Hz EA:Intravitreal injection ofδ-opioid receptor antagonist Naltridole(10µl,100 nM)30 min before RIR injury induction,followed by 2 Hz EA treatment at Xinming and BL1 for 30 min.In vitro studies examined enkephalins'effects on oxygen–glucose deprivation/reperfusion(OGD/R)induced injury in ARPE‐19 cells.Cell viability was evaluated by cell counting kit-8(CCK-8)assay,and morphological changes were recorded by Molecular Devices.Apoptosis was detected by Annexin V-FITC flow cytometry.Delta opioid receptor(DOR)expression in total protein and membrane protein were analyzed by western blotting(WB).Immunofluorescence(IF)staining and WB assessed ZO-1 and Claudin-19.For cell-based assays,n indicates the number of biologically independent replicates.Results It was found that 2 Hz EA treatment increased enkephalins(methionine-enkephalin and leucine-enkephalin)levels(P<0.01),restoring the increased retinal thickness(P<0.05)and mitigating RGCs loss(P<0.05)post-RIR injury.FITC-dextran leakage in the outer retina was ameliorated by 2 Hz EA(P<0.05),reversibly countered by Naltrindole(P<0.05),a DOR antagonist.Treatment with 30µM enkephalins enhanced ARPE-19 cell viability(P<0.001,P<0.0001)and inhibited apoptosis(P<0.0001).Enkephalins elevated DOR levels in total protein(P<0.05)and membrane protein fractions(P<0.001,P<0.0001),as well as elevated ZO-1(P<0.001,P<0.01)and Claudin-19(P<0.0001,P<0.001)levels following OGD/R,counteracted by Naltrindole.Conclusion It was found that 2 Hz EA inhibits the breakdown of OBRB via enkephalins activate DOR in RIR injury.展开更多
The complexity of the seismicity pattern for the subduction zone along the oceanic plate triggered the outer rise events and revealed cyclic tectonic deformation conditions along the plate subduction zones.The outer r...The complexity of the seismicity pattern for the subduction zone along the oceanic plate triggered the outer rise events and revealed cyclic tectonic deformation conditions along the plate subduction zones.The outer rise earthquakes have been observed along the Sunda arc,following the estimated rupture area of the 2005 M_(W)8.6 Nias earthquakes.Here,we used kinematic waveform inversion(KIWI)to obtain the source parameters of the 14 May 2021 M_(W)6.6 event off the west coast of northern Sumatra and to define the fault plane that triggered this outer rise event.The KIWI algorithm allows two types of seismic source to be configured:the moment tensor model to describe the type of shear with six moment tensor components and the Eikonal model for the rupture of pure double-couple sources.This method was chosen for its flexibility to be applied for different sources of seismicity and also for the automated full-moment tensor solution with real-time monitoring.We used full waveform traces from 8 broadband seismic stations within 1000 km epicentral distances sourced from the Incorporated Research Institutions for Seismology(IRIS-IDA)and Geofon GFZ seismic record databases.The initial origin time and hypocenter values are obtained from the IRIS-IDA.The synthetic seismograms used in the inversion process are based on the existing regional green function database model and were accessed from the KIWI Tools Green's Function Database.The obtained scalar seismic moment value is 1.18×10^(19)N·m,equivalent to a moment magnitude M_(W)6.6.The source parameters are 140°,44°,and−99°for the strike,dip,and rake values at a centroid depth of 10.2 km,indicating that this event is a normal fault earthquake that occurred in the outer rise area.The outer rise events with normal faults typically occur at the shallow part of the plate,with nodal-plane dips predominantly in the range of 30°-60°on the weak oceanic lithosphere due to hydrothermal alteration.The stress regime around the plate subduction zone varies both temporally and spatially due to the cyclic influences of megathrust earthquakes.Tensional outer rise earthquakes tend to occur after the megathrust events.The relative timing of these events is not known due to the viscous relaxation of the down going slab and poroelastic response in the trench slope region.The occurrence of the 14 May 2021 earthquake shows the seismicity in the outer rise region in the strongly coupled Sunda arc subduction zone due to elastic bending stress within the duration of the seismic cycle.展开更多
The legal framework for outer space governance,centered on the“Five Major Treaties”,is facing significant challenges.In the face of numerous variables that will shape the future order of outer space,an intrinsic dem...The legal framework for outer space governance,centered on the“Five Major Treaties”,is facing significant challenges.In the face of numerous variables that will shape the future order of outer space,an intrinsic demand for transformation has emerged within the governance of outer space.Under the leadership of the new wave of space technology revolutions and commercial innovations,outer space governance will undergo a profound transformation.New theories in space law will emerge,engage in long-term competition,and ultimately contribute to the formation of a completely new governance structure.展开更多
Sensitivity encoding(SENSE)is a parallel magnetic resonance imaging(MRI)reconstruction model by utilizing the sensitivity information of receiver coils to achieve image reconstruction.The existing SENSE-based reconstr...Sensitivity encoding(SENSE)is a parallel magnetic resonance imaging(MRI)reconstruction model by utilizing the sensitivity information of receiver coils to achieve image reconstruction.The existing SENSE-based reconstruction algorithms usually used nonadaptive sparsifying transforms,resulting in a limited reconstruction accuracy.Therefore,we proposed a new model for accurate parallel MRI reconstruction by combining the L0 norm regularization term based on the efficient sum of outer products dictionary learning(SOUPDIL)with the SENSE model,called SOUPDIL-SENSE.The SOUPDIL-SENSE model is mainly solved by utilizing the variable splitting and alternating direction method of multipliers techniques.The experimental results on four human datasets show that the proposed algorithm effectively promotes the image sparsity,eliminates the noise and artifacts of the reconstructed images,and improves the reconstruction accuracy.展开更多
To address the common issues of wrinkling,tearing,and uneven wall thickness in the actual sheet metal stamp-ing process of the outer ring of needle roller bearings,this study analyzes critical technical indicators suc...To address the common issues of wrinkling,tearing,and uneven wall thickness in the actual sheet metal stamp-ing process of the outer ring of needle roller bearings,this study analyzes critical technical indicators such asforming limits,thickness distribution,and principal strains in the forming process in detail.Three-dimensionalmodels of the concave and convex dies were constructed.The effects of different process parameters,includingstamping speed,edge pressure,sheet metal thickness,and friction coefficient,on the quality of the forming partswere investigated by varying these parameters.Subsequently,the orthogonal experimental method was used todetermine an optimal experimental group from multiple sets of experiments.It was found that under the processparameters of a stamping speed of 3000 mm/s,edge pressure of 2000 N,sheet metal thickness of 0.9 mm,andfriction coefficient of 0.125,the forming quality of the outer ring of the bearing is ideal.展开更多
Birch outer bark(BOB)from Betula pendula Roth.is a unique and valuable biomass feedstock that contains suberin.The biopolyester suberin is built from bifunctional fatty acids-suberinic acids(SA)-which can be obtained ...Birch outer bark(BOB)from Betula pendula Roth.is a unique and valuable biomass feedstock that contains suberin.The biopolyester suberin is built from bifunctional fatty acids-suberinic acids(SA)-which can be obtained through a depolymerization process in an alkaline medium and used as a binder due to their adhesive properties.The aim of this study was to develop the SA-containing binder and identify suitable pressing conditions to produce plywood that meets the shear strength requirements of the EN 314-2 standard 3rd moisture resistance class for bonding quality,ensuring durability in unprotected exterior conditions(shear strength≥1 N/mm^(2)).The raw BOB material was modified by extraction,milling,and fractionation,and the depolymerization methodology was enhanced by additional sieving to improve the adhesive properties of the obtained binders.Several analytical methods were used to characterize the feedstock and the binders.Higher heating value was used to assess the pure outer bark content of BOB.GC-MS and GPC were used to describe the monomeric and oligomeric composition of binders.TGA was used to describe the biopolymeric composition and DSC was used to determine the thermal behavior of the binders.As a result,successful modification of feedstock(extracted BOB,milled through 2 mm sieve,1-2 mm fraction used)and its depolymerization process(implementing the separation of coarse ligno-carbohydrate particles by 1 mm mesh sieve)was employed to obtain a binder for which suitable hot-pressing parameters were determined−200℃for 5 min at 1.8 MPa.Consequently,plywood with shear strength of 1.26±0.18 N/mm^(2),which adheres to the EN 314-2 standards 3rd moisture resistance class,was obtained.展开更多
Tumor treatment remains a significant medical challenge,with many traditional therapies causing notable side effects.Recent research has led to the development of immunotherapy,which offers numerous advantages.Bacteri...Tumor treatment remains a significant medical challenge,with many traditional therapies causing notable side effects.Recent research has led to the development of immunotherapy,which offers numerous advantages.Bacteria inherently possess motility,allowing them to preferentially colonize tumors and modulate the tumor immune microenvironment,thus influencing the efficacy of immunotherapy.Bacterial outer membrane vesicles(OMVs)secreted by gram-negative bacteria are nanoscale lipid bilayer structures rich in bacterial antigens,pathogen-associated molecular patterns(PAMPs),various proteins,and vesicle structures.These features allow OMVs to stimulate immune system activation,generate immune responses,and serve as efficient drug delivery vehicles.This dual capability enhances the effectiveness of immunotherapy combined with chemotherapy or phototherapy,thereby improving anticancer drug efficacy.Current research has concentrated on engineering OMVs to enhance production yield,minimize cytotoxicity,and improve the safety and efficacy of treatments.Consequently,OMVs hold great promise for applications in tumor immunotherapy,tumor vaccine development,and drug delivery.This article provides an overview of the structural composition and immune mechanisms of OMVs,details various OMVs modification strategies,and reviews the progress in using OMVs for tumor treatment and their anti-tumor mechanisms.Additionally,it discusses the challenges faced in translating OMV-based anti-tumor therapies into clinical practice,aiming to provide a comprehensive understanding of OMVs'potential for in-depth research and clinical application.展开更多
The external rotor hub motor adopts direct drive mode,no deceleration drive device,and has a compact structure.Its axial size is smaller than that of a deceleration-driven hub motor,which greatly reduces the weight of...The external rotor hub motor adopts direct drive mode,no deceleration drive device,and has a compact structure.Its axial size is smaller than that of a deceleration-driven hub motor,which greatly reduces the weight of the vehicle and increases the cruising range of the vehicle.Because of the limited special working environment and performance requirements,the hub motor has a small internal space and a large heat generation,so it puts forward higher requirements for heat dissipation capacity.For the external rotor hub motor,a new type of in-tank watercooled structure of hub motor was proposed to improve its cooling effect and performance.Firstly,the threedimensional finite element model of the motor is established to analyze the characteristics of motor loss and temperature field distribution.Secondly,the cooling performance of different cooling structures in the tank was studied.Finally,the thermal network model and three-dimensional finite element analysis were used to optimize the water-cooled structure in the tank,and the power density of themotor was improved by improving the cooling performance under the condition of volume limitation of the hub motor.The results show that the cooling effect of the proposed water-cooled structure in the tank is significant under the condition of constant power density.Compared to natural ventilation,the maximum temperature was reduced by 33.13°C and the cooling effect was increased by about 27.7%.展开更多
The reservoir-monolithic type of the controlled release systems is investigated currently,however,the existing kinetic model could not describe the release process well because the release kinetics is rather complicat...The reservoir-monolithic type of the controlled release systems is investigated currently,however,the existing kinetic model could not describe the release process well because the release kinetics is rather complicated.In this paper,a simplified release kinetic model for diffusion-controlled monolithic matrix coated with outer membrane systems is proposed and verified by the experimental data of mercaptopurinum release experiment.It shows that the model can well describe the release mechanism (the relative error is under 3%) when drug loading (C d) is above its solubility limit (C s).At the same time,the release characteristics of special cases (D mD f and D mD f) are discussed theoretically.When D mD f the release rate becomes constant,namely,zero order release,and the release rate is independent of the drug membrane.This result provides the theoretical basis for the system of zero order release as well as how to control the release rate and the amount of drug release.When D mD f,the release rate is dependent on the drug release coefficient in the monolithic matrix,solubility and drug loading but independent of the process in the outer membrane,and it is similar to monolithic matrix type.展开更多
Diabetic macular edema(DME) is the most common cause of vision loss in diabetic retinopathy,affecting 1 in 15 patients with diabetes mellitus(DM).The disruption of the inner blood-retina barrier(BRB) has been largely ...Diabetic macular edema(DME) is the most common cause of vision loss in diabetic retinopathy,affecting 1 in 15 patients with diabetes mellitus(DM).The disruption of the inner blood-retina barrier(BRB) has been largely investigated and attributed the primary role in the pathogenesis and progression in DME, but there is increasing evidence regarding the role of outer BRB, separating the RPE from the underlying choriocapillaris,in the occurrence and evolution of DME.The development of novel imaging technologies has led to major improvement in the field of in vivo structural analysis of the macula allowing us to delve deeper into the pathogenesis of DME and expanding our vision regarding this condition.In this review we gathered the results of studies that investigated specific outer BRB optical coherence tomography parameters in patients with DM with the aim to outline the current status of its role in the pathogenesis and progression of DME and identify new research pathways contributing to the advancement of knowledge in the understanding of this condition.展开更多
The elasto-gravitational deformation response of the Earths solid parts to the perturbations of the pressure and gravity on the core-mantle boundary (CMB) and the solid inner core boundary (ICB), due to the dynamical ...The elasto-gravitational deformation response of the Earths solid parts to the perturbations of the pressure and gravity on the core-mantle boundary (CMB) and the solid inner core boundary (ICB), due to the dynamical behaviors of the fluid outer core (FOC), is discussed. The internal load Love numbers, which are formulized in a general form in this study, are employed to describe the Earths deformation. The preliminary reference Earth model (PREM) is used as an example to calculate the internal load Love numbers on the Earths surface, CMB and ICB, respectively. The characteristics of the Earths deformation variation with the depth and the perturbation periods on the boundaries of the FOC are also investigated. The numerical results indicate that the internal load Love numbers decrease quickly with the increasing degree of the spherical harmonics of the displacement and depend strongly on the perturbation frequencies, especially on the high frequencies. The results, obtained in this work, can be used to construct the boundary conditions for the core dynamics of the long-period oscillations of the Earths fluid outer core.展开更多
[Objective] This study aimed to investigate the outer membrane protein （OMP） patterns of Escherichia coli 038, 053 and 075 isolates from chickens. [Method] Eight pathogenic E. coil isolates with various serotypes we...[Objective] This study aimed to investigate the outer membrane protein （OMP） patterns of Escherichia coli 038, 053 and 075 isolates from chickens. [Method] Eight pathogenic E. coil isolates with various serotypes were used as experimental materials to extract OMP by using supersonic schizolysis method and Sarcosyl. After SDS-PAGE electrophoresis, OMP patterns of the extracted products were determined based on the OMP model diagram. [Result] OMP of eight E. coil isolates with three serotypes were divided into three patterns, to be specific, 2 075 isolates respectively belonged to OMP-I and OMP-II pattern, 1 053 isolate belonged to OMP-II pattern, and 5 038 isolates belonged to OMP-I and OMP-III pattern. [Conclusion] Experimental results showed that E. coli isolates with the same serotype may belong to completely different OMP patterns, while serologically unrelated isolates may belong to the same OMP pattern. OMP of E. coil isolates with the same serotype may generate genetic differentiation; in addition, OMP of E. coli isolates with different serotypes may have different genetic correlation.展开更多
Objective: To construct a recombinant plasmid containing the outer membrane protein 2 (Omp2) gene of Chlamydia trachomatis and express Omp2 in E.coli. Methods: The omp2 gene of C. trachomatis serovar D was cloned into...Objective: To construct a recombinant plasmid containing the outer membrane protein 2 (Omp2) gene of Chlamydia trachomatis and express Omp2 in E.coli. Methods: The omp2 gene of C. trachomatis serovar D was cloned into pQE30 vector following PCR amplification from genomic DNA. E. coli M15 transformants were induced to express the fusion protein by IPTG and the product was identified by SDS-PAGE and Western blot. Results: Confirmed by enzyme cleavage analysis and DNA sequencing, a correct recombinant plasmid pQE30/omp2 was constructed. The fusion protein from the transformants was approximately 60 kDa in size in SDS-PAGE analysis, which could specially react with anti-6 X His mouse monoclonal IgG antibodies. Conclusion: We successfully expressed Omp2 in E. coli M15, providing an efficient and simple system for assaying the immunological properties of Omp2.展开更多
Semi-floating ring bearing（SFRB） is developed to control the vibration of turbocharger rotor. The outer clearance of SFRB affects the magnitude and frequency of nonlinear whirl motion, which is significant for the d...Semi-floating ring bearing（SFRB） is developed to control the vibration of turbocharger rotor. The outer clearance of SFRB affects the magnitude and frequency of nonlinear whirl motion, which is significant for the design of turbocharger. In order to explore the effects of outer clearance, a transient finite element analysis program for rotor and oil film bearing is built and validated by a published experimental case. The nonlinear dynamic behaviors ofrotor-SFRB system are simulated. According to the simulation results, two representative subsynchronous oscillations excited by the two hearings respectively are discovered. As the outer clearance of SFRB increases from 24 ~tm to 60 pro, the low-frequency subsynchronous oscillation experiences three steps, including a strong start, a gradual recession and a combination with the other one. At the same time, the high-frequency subsynchronous oscillation starts to appear gradually, then strengthens, and finally combines. If gravity and unbalance are neglected, the combination will start starts from high rotor speed and extents to low rotor speed, just like a ＂zipper＂. It is found from the quantitative analysis that when the outer clearance increases, the vibration amplitude experiences large value firstly, then reduction, and suddenly increasing after combination. A useful design principle of SFRB outer clearance for minimum vibration amplitude is proposed： the outer clearance value should be chosen to keep the frequency of two subsynchronous oscillations clearly separated and their amplitudes close.展开更多
Idealized numerical simulations are conducted in this study to comparatively investigate the characteristics of the stratiform sector in the outer rainbands of tropical cyclones(TCs)in lower-and upper-layer vertical w...Idealized numerical simulations are conducted in this study to comparatively investigate the characteristics of the stratiform sector in the outer rainbands of tropical cyclones(TCs)in lower-and upper-layer vertical wind shear(VWS)with moderate magnitude.Consistent with the results in previous studies,the outer rainband stratiform sector of the TCs simulated in both experiments is generally located downshear left.Upper-layer VWS tends to produce stronger asymmetric outflow at upper levels in the downshear-left quadrant than lower-layer shear.This stronger asymmetric outflow transports more water vapor radially outward from the inner core to the outer core at upper levels in the downshear-left quadrant in the upper-layer shear experiment.More depositional growth of both graupel and cloud ice thus occurs downshear left in upper layers in the outer core,yielding more diabatic heating and stronger upward motions,particularly in the stratiformdominated part of the stratiform sector in the upper-layer shear experiment.Resultingly,a better-organized stratiform sector in the outer rainbands is found in the upper-layer VWS experiment than in the lower-layer VWS experiment.The diabatic heating associated with the stratiform sector produces strong midlevel outflow on the radially inward side of,and weak midlevel inflow on the radially outward side of,the heating core,with lower-level inflow beneath the midlevel outflow and upper-level inflow above.The upper-layer VWS tends to produce a deeper asymmetric inflow layer in the outer rainband stratiform sector,with more significant lower-level inflow and tangential jets in the upper-layer VWS experiment.展开更多
文摘Ownership is an increasingly important conflict in outer space at this moment in time.Despite the principle in the Outer Space Treaty(1967),that emphasizes the importance of all states'free access to outer space based on equality for exploration and use.Moreover,outer space including the Moon and other celestial bodies is not subject to national appropriation by claim of sovereignty,by means of use or occupation,or by any other means.However,outer space activity is not free from sovereignty and jurisdiction after all.Anyway,the legal situation relating to space resource exploitation and utilization activities under the adoption of United Nations is a challenge.Some scholars implied that the Outer Space Treaty(1967)clearly prohibits appropriation of whole celestial bodies but is far less clear concerning the rights of over-extracted resources.Nevertheless,the Moon Agreement(1979)promotes the idea of property ownership of over-extracted resources.It permits states to collect and remove samples of lunar minerals and other substances for further interest in scientific investigation.The application of the Moon Agreement(1979)is not only to the Moon itself but to other celestial bodies,thus potentially covering the planets and asteroids where the mining potential is considered to be limitless.Under this circumstance,numerous countries,such as the United States,Luxembourg,The United Arab Emirates,and Japan have enacted legal regimes that glorify the rights of their entities in mineral resources in outer space.However,these regimes could be disputed under the international legal framework if countries have merely interpreted and applied their rights and obligations on a national level as they understand them.Therefore,this paper purports to clarify the ownership rights in outer space and analyze the purpose of the legal situation relating to space resource exploitation and utilization activities under the adoption of the United States,Luxembourg,The United Arab Emirates,and Japan.
基金supported by the Army Laboratory Animal Foundation of China,No.SYDW[2020]22(to TC)the Shaanxi Provincial Key R&D Plan General Project of China,No.2022SF-236(to YM)the National Natural Science Foundation of China,No.82202070(to TC)。
文摘A microgravity environment has been shown to cause ocular damage and affect visual acuity,but the underlying mechanisms remain unclear.Therefore,we established an animal model of weightlessness via tail suspension to examine the pathological changes and molecular mechanisms of retinal damage under microgravity.After 4 weeks of tail suspension,there were no notable alterations in retinal function and morphology,while after 8 weeks of tail suspension,significant reductions in retinal function were observed,and the outer nuclear layer was thinner,with abundant apoptotic cells.To investigate the mechanism underlying the degenerative changes that occurred in the outer nuclear layer of the retina,proteomics was used to analyze differentially expressed proteins in rat retinas after 8 weeks of tail suspension.The results showed that the expression levels of fibroblast growth factor 2(also known as basic fibroblast growth factor)and glial fibrillary acidic protein,which are closely related to Müller cell activation,were significantly upregulated.In addition,Müller cell regeneration and Müller cell gliosis were observed after 4 and 8 weeks,respectively,of simulated weightlessness.These findings indicate that Müller cells play an important regulatory role in retinal outer nuclear layer degeneration during weightlessness.
文摘AIM:To comprehensively examine the clinical presentations,multimodal images,and long-term follow-up of Chinese patients with acute zonal occult outer retinopathy(AZOOR),a rare inflammatory disorder.METHODS:This was a retrospective study.A total of 20 patients(32 eyes)were included.The medical records and multimodal imaging,including wide-field fundus photography,wide-field fundus autofluorescence(FAF),and swept-source optical coherence tomography(SS-OCT)were analyzed.RESULTS:The study included 20 patients with a mean age of 38.2±10.9y,and females accounted for 60%.Lesions could involve peripapillary areas,macular region,and peripheral retina.The mean best-corrected visual acuity(BCVA)at presentation was 0.38±0.60 logMAR,with no significant difference in visual acuity between acute cases(within 6mo of onset)and chronic cases(beyond 6mo of onset;P=0.390).There was no statistically significant difference in visual acuity between eyes of acute case(within 6mo of onset)and the chronic case(beyond 6mo of onset).In some chronic case,FAF examination revealed the presence of a hyperautofluorescent(hyperAF)ring around the macular area(6/18),a phenomenon not observed in the acute case(P=0.024).A higher proportion of chronic cases showed predominantly hypoautofluorescent(hypoAF)lesions compared to the acute case(13/18 vs 2/14,P=0.0016).SS-OCT examination showed that both acute and chronic cases exhibited hyperreflective dots above the retinal pigment epithelium(RPE),and ellipsoid zone(EZ)and RPE damage.In the chronic case,eyes with hyperreflective dots above the RPE were more likely to exhibit EZ and RPE damage in the macular region compared to those without these dots.CONCLUSION:Multimodal imaging plays a crucial role in the follow-up of patients with AZOOR.In chronic cases of AZOOR,the presence of hyperreflective dots above the RPE indicates a higher likelihood of outer retinal involvement in the macular region.This study provides critical insights into the complex presentation and progression of AZOOR.
基金Supported by the National Natural Science Foundation of China:81574078。
文摘Objectives Retinal ischemia-reperfusion(RIR)injury results in irreversible visual impairments.The disruption of the outer blood-retinal barrier(OBRB)is a major ocular pathogenic process that RIR injury affects.Current clinical strategies are limited.This study aimed to elucidate how electroacupuncture(EA)protects the OBRB against RIR injury.Methods Male Wistar rats(7 weeks old,250 g to 280 g)were used in this study.Three independent experiments were conducted.First,Opioid peptide levels were quantified using enzyme-linked immunosorbent assay(ELISA).42 rats were randomly divided into 7 groups(n=6/group):Control:No treatment;high intraocular pressure(HIOP):Acute intraocular pressure elevation-induced RIR injury;HIOP+SHAM EA:RIR injury+sham EA at Xinming(Extra acupoint)and Jingming(BL1)for 30 min(shallow needle insertion but without electric stimulation);HIOP+2 Hz EA:RIR injury+2 Hz EA at Xinming and BL1 for 30 min;HIOP+100 Hz:RIR injury+100 Hz EA at Xinming and BL1 for 30 min;HIOP+2/100 Hz EA:RIR injury+2/100 Hz EA at Xinming and BL1 for 30 min;HIOP+4/20 Hz EA:RIR injury+4/20 Hz EA at Xinming and BL1 for 30 min.Second,retinal morphology was assessed by hematoxylin and eosin(HE)staining.20 rats were randomly allocated into 4 groups(n=5/group):Control:No treatment;HIOP:Acute intraocular pressure elevation-induced RIR injury;HIOP+SHAM EA:RIR injury+sham EA at Xinming and BL1 for 30 min(shallow needle insertion but without electric stimulation);HIOP+2 Hz EA:RIR injury+2 Hz EA at Xinming and BL1 for 30 min.Third,the permeability of OBRB was evaluated using the fluorescein isothiocyanate(FITC)-dextran leakage assay.15 rats were randomly divided into 5 groups(n=3/group):Control:No treatment;HIOP:Acute intraocular pressure elevation-induced RIR injury;HIOP+SHAM EA:RIR injury+sham EA at Xinming and BL1 for 30 min(shallow needle insertion but without electric stimulation);HIOP+2 Hz EA:RIR injury+2 Hz EA at Xinming and BL1 for 30 min;Nal+HIOP+2 Hz EA:Intravitreal injection ofδ-opioid receptor antagonist Naltridole(10µl,100 nM)30 min before RIR injury induction,followed by 2 Hz EA treatment at Xinming and BL1 for 30 min.In vitro studies examined enkephalins'effects on oxygen–glucose deprivation/reperfusion(OGD/R)induced injury in ARPE‐19 cells.Cell viability was evaluated by cell counting kit-8(CCK-8)assay,and morphological changes were recorded by Molecular Devices.Apoptosis was detected by Annexin V-FITC flow cytometry.Delta opioid receptor(DOR)expression in total protein and membrane protein were analyzed by western blotting(WB).Immunofluorescence(IF)staining and WB assessed ZO-1 and Claudin-19.For cell-based assays,n indicates the number of biologically independent replicates.Results It was found that 2 Hz EA treatment increased enkephalins(methionine-enkephalin and leucine-enkephalin)levels(P<0.01),restoring the increased retinal thickness(P<0.05)and mitigating RGCs loss(P<0.05)post-RIR injury.FITC-dextran leakage in the outer retina was ameliorated by 2 Hz EA(P<0.05),reversibly countered by Naltrindole(P<0.05),a DOR antagonist.Treatment with 30µM enkephalins enhanced ARPE-19 cell viability(P<0.001,P<0.0001)and inhibited apoptosis(P<0.0001).Enkephalins elevated DOR levels in total protein(P<0.05)and membrane protein fractions(P<0.001,P<0.0001),as well as elevated ZO-1(P<0.001,P<0.01)and Claudin-19(P<0.0001,P<0.001)levels following OGD/R,counteracted by Naltrindole.Conclusion It was found that 2 Hz EA inhibits the breakdown of OBRB via enkephalins activate DOR in RIR injury.
基金supported by the National Natural Science Foundation of China(Grant No.42130312)。
文摘The complexity of the seismicity pattern for the subduction zone along the oceanic plate triggered the outer rise events and revealed cyclic tectonic deformation conditions along the plate subduction zones.The outer rise earthquakes have been observed along the Sunda arc,following the estimated rupture area of the 2005 M_(W)8.6 Nias earthquakes.Here,we used kinematic waveform inversion(KIWI)to obtain the source parameters of the 14 May 2021 M_(W)6.6 event off the west coast of northern Sumatra and to define the fault plane that triggered this outer rise event.The KIWI algorithm allows two types of seismic source to be configured:the moment tensor model to describe the type of shear with six moment tensor components and the Eikonal model for the rupture of pure double-couple sources.This method was chosen for its flexibility to be applied for different sources of seismicity and also for the automated full-moment tensor solution with real-time monitoring.We used full waveform traces from 8 broadband seismic stations within 1000 km epicentral distances sourced from the Incorporated Research Institutions for Seismology(IRIS-IDA)and Geofon GFZ seismic record databases.The initial origin time and hypocenter values are obtained from the IRIS-IDA.The synthetic seismograms used in the inversion process are based on the existing regional green function database model and were accessed from the KIWI Tools Green's Function Database.The obtained scalar seismic moment value is 1.18×10^(19)N·m,equivalent to a moment magnitude M_(W)6.6.The source parameters are 140°,44°,and−99°for the strike,dip,and rake values at a centroid depth of 10.2 km,indicating that this event is a normal fault earthquake that occurred in the outer rise area.The outer rise events with normal faults typically occur at the shallow part of the plate,with nodal-plane dips predominantly in the range of 30°-60°on the weak oceanic lithosphere due to hydrothermal alteration.The stress regime around the plate subduction zone varies both temporally and spatially due to the cyclic influences of megathrust earthquakes.Tensional outer rise earthquakes tend to occur after the megathrust events.The relative timing of these events is not known due to the viscous relaxation of the down going slab and poroelastic response in the trench slope region.The occurrence of the 14 May 2021 earthquake shows the seismicity in the outer rise region in the strongly coupled Sunda arc subduction zone due to elastic bending stress within the duration of the seismic cycle.
文摘The legal framework for outer space governance,centered on the“Five Major Treaties”,is facing significant challenges.In the face of numerous variables that will shape the future order of outer space,an intrinsic demand for transformation has emerged within the governance of outer space.Under the leadership of the new wave of space technology revolutions and commercial innovations,outer space governance will undergo a profound transformation.New theories in space law will emerge,engage in long-term competition,and ultimately contribute to the formation of a completely new governance structure.
基金the National Natural Science Foundation of China(No.61861023)the Yunnan Fundamental Research Project(No.202301AT070452)。
文摘Sensitivity encoding(SENSE)is a parallel magnetic resonance imaging(MRI)reconstruction model by utilizing the sensitivity information of receiver coils to achieve image reconstruction.The existing SENSE-based reconstruction algorithms usually used nonadaptive sparsifying transforms,resulting in a limited reconstruction accuracy.Therefore,we proposed a new model for accurate parallel MRI reconstruction by combining the L0 norm regularization term based on the efficient sum of outer products dictionary learning(SOUPDIL)with the SENSE model,called SOUPDIL-SENSE.The SOUPDIL-SENSE model is mainly solved by utilizing the variable splitting and alternating direction method of multipliers techniques.The experimental results on four human datasets show that the proposed algorithm effectively promotes the image sparsity,eliminates the noise and artifacts of the reconstructed images,and improves the reconstruction accuracy.
基金supported by the China Postdoctoral Science Foundation(Grant No.2022M721395)the National Natural Science Foundation of China(Grant No.72072089).
文摘To address the common issues of wrinkling,tearing,and uneven wall thickness in the actual sheet metal stamp-ing process of the outer ring of needle roller bearings,this study analyzes critical technical indicators such asforming limits,thickness distribution,and principal strains in the forming process in detail.Three-dimensionalmodels of the concave and convex dies were constructed.The effects of different process parameters,includingstamping speed,edge pressure,sheet metal thickness,and friction coefficient,on the quality of the forming partswere investigated by varying these parameters.Subsequently,the orthogonal experimental method was used todetermine an optimal experimental group from multiple sets of experiments.It was found that under the processparameters of a stamping speed of 3000 mm/s,edge pressure of 2000 N,sheet metal thickness of 0.9 mm,andfriction coefficient of 0.125,the forming quality of the outer ring of the bearing is ideal.
基金supported according to contract No.5.1.1.2.i.0/1/22/A/CFLA/007 between“Forest Sector Competence Centre of Latvia”Ltd.,and the Central Finance and Contracting Agency which dated 20th January of 2023.
文摘Birch outer bark(BOB)from Betula pendula Roth.is a unique and valuable biomass feedstock that contains suberin.The biopolyester suberin is built from bifunctional fatty acids-suberinic acids(SA)-which can be obtained through a depolymerization process in an alkaline medium and used as a binder due to their adhesive properties.The aim of this study was to develop the SA-containing binder and identify suitable pressing conditions to produce plywood that meets the shear strength requirements of the EN 314-2 standard 3rd moisture resistance class for bonding quality,ensuring durability in unprotected exterior conditions(shear strength≥1 N/mm^(2)).The raw BOB material was modified by extraction,milling,and fractionation,and the depolymerization methodology was enhanced by additional sieving to improve the adhesive properties of the obtained binders.Several analytical methods were used to characterize the feedstock and the binders.Higher heating value was used to assess the pure outer bark content of BOB.GC-MS and GPC were used to describe the monomeric and oligomeric composition of binders.TGA was used to describe the biopolymeric composition and DSC was used to determine the thermal behavior of the binders.As a result,successful modification of feedstock(extracted BOB,milled through 2 mm sieve,1-2 mm fraction used)and its depolymerization process(implementing the separation of coarse ligno-carbohydrate particles by 1 mm mesh sieve)was employed to obtain a binder for which suitable hot-pressing parameters were determined−200℃for 5 min at 1.8 MPa.Consequently,plywood with shear strength of 1.26±0.18 N/mm^(2),which adheres to the EN 314-2 standards 3rd moisture resistance class,was obtained.
基金supported by the National Natural Science Foundation of China(Grant Nos.:52122317 and 22175120)the Science and Technology Foundation of Shenzhen City,China(Grant Nos.:JCYJ20210324142211031,RCYX20200714114525101,and RCYX20220809130438001)+5 种基金the Pearl River Talent Recruitment Program,China(Program No.:2019QN01Y103)the Medical-Engineering Interdisciplinary Research Foundation of Shenzhen University,China(Grant No.:2023YG021)the Research Team Cultivation Program of Shenzhen University,China(Program No.:2023QNT003)the Jiaxing Public Welfare Research Program Project,China(Program No.:2023AY11018)the project supported by Scientific Research Fund of Zhejiang Provincial Education Department,China(Project No.:Y202352075)Arshad Khan thanks the research support by King Abdullah International Medical Research Center(KAIMRC),Saudi Arabia through start up grant(Grant No.:SF23/006/R).
文摘Tumor treatment remains a significant medical challenge,with many traditional therapies causing notable side effects.Recent research has led to the development of immunotherapy,which offers numerous advantages.Bacteria inherently possess motility,allowing them to preferentially colonize tumors and modulate the tumor immune microenvironment,thus influencing the efficacy of immunotherapy.Bacterial outer membrane vesicles(OMVs)secreted by gram-negative bacteria are nanoscale lipid bilayer structures rich in bacterial antigens,pathogen-associated molecular patterns(PAMPs),various proteins,and vesicle structures.These features allow OMVs to stimulate immune system activation,generate immune responses,and serve as efficient drug delivery vehicles.This dual capability enhances the effectiveness of immunotherapy combined with chemotherapy or phototherapy,thereby improving anticancer drug efficacy.Current research has concentrated on engineering OMVs to enhance production yield,minimize cytotoxicity,and improve the safety and efficacy of treatments.Consequently,OMVs hold great promise for applications in tumor immunotherapy,tumor vaccine development,and drug delivery.This article provides an overview of the structural composition and immune mechanisms of OMVs,details various OMVs modification strategies,and reviews the progress in using OMVs for tumor treatment and their anti-tumor mechanisms.Additionally,it discusses the challenges faced in translating OMV-based anti-tumor therapies into clinical practice,aiming to provide a comprehensive understanding of OMVs'potential for in-depth research and clinical application.
基金supported by National Science Foundation of China(Grant No.51705306).
文摘The external rotor hub motor adopts direct drive mode,no deceleration drive device,and has a compact structure.Its axial size is smaller than that of a deceleration-driven hub motor,which greatly reduces the weight of the vehicle and increases the cruising range of the vehicle.Because of the limited special working environment and performance requirements,the hub motor has a small internal space and a large heat generation,so it puts forward higher requirements for heat dissipation capacity.For the external rotor hub motor,a new type of in-tank watercooled structure of hub motor was proposed to improve its cooling effect and performance.Firstly,the threedimensional finite element model of the motor is established to analyze the characteristics of motor loss and temperature field distribution.Secondly,the cooling performance of different cooling structures in the tank was studied.Finally,the thermal network model and three-dimensional finite element analysis were used to optimize the water-cooled structure in the tank,and the power density of themotor was improved by improving the cooling performance under the condition of volume limitation of the hub motor.The results show that the cooling effect of the proposed water-cooled structure in the tank is significant under the condition of constant power density.Compared to natural ventilation,the maximum temperature was reduced by 33.13°C and the cooling effect was increased by about 27.7%.
文摘The reservoir-monolithic type of the controlled release systems is investigated currently,however,the existing kinetic model could not describe the release process well because the release kinetics is rather complicated.In this paper,a simplified release kinetic model for diffusion-controlled monolithic matrix coated with outer membrane systems is proposed and verified by the experimental data of mercaptopurinum release experiment.It shows that the model can well describe the release mechanism (the relative error is under 3%) when drug loading (C d) is above its solubility limit (C s).At the same time,the release characteristics of special cases (D mD f and D mD f) are discussed theoretically.When D mD f the release rate becomes constant,namely,zero order release,and the release rate is independent of the drug membrane.This result provides the theoretical basis for the system of zero order release as well as how to control the release rate and the amount of drug release.When D mD f,the release rate is dependent on the drug release coefficient in the monolithic matrix,solubility and drug loading but independent of the process in the outer membrane,and it is similar to monolithic matrix type.
文摘Diabetic macular edema(DME) is the most common cause of vision loss in diabetic retinopathy,affecting 1 in 15 patients with diabetes mellitus(DM).The disruption of the inner blood-retina barrier(BRB) has been largely investigated and attributed the primary role in the pathogenesis and progression in DME, but there is increasing evidence regarding the role of outer BRB, separating the RPE from the underlying choriocapillaris,in the occurrence and evolution of DME.The development of novel imaging technologies has led to major improvement in the field of in vivo structural analysis of the macula allowing us to delve deeper into the pathogenesis of DME and expanding our vision regarding this condition.In this review we gathered the results of studies that investigated specific outer BRB optical coherence tomography parameters in patients with DM with the aim to outline the current status of its role in the pathogenesis and progression of DME and identify new research pathways contributing to the advancement of knowledge in the understanding of this condition.
文摘The elasto-gravitational deformation response of the Earths solid parts to the perturbations of the pressure and gravity on the core-mantle boundary (CMB) and the solid inner core boundary (ICB), due to the dynamical behaviors of the fluid outer core (FOC), is discussed. The internal load Love numbers, which are formulized in a general form in this study, are employed to describe the Earths deformation. The preliminary reference Earth model (PREM) is used as an example to calculate the internal load Love numbers on the Earths surface, CMB and ICB, respectively. The characteristics of the Earths deformation variation with the depth and the perturbation periods on the boundaries of the FOC are also investigated. The numerical results indicate that the internal load Love numbers decrease quickly with the increasing degree of the spherical harmonics of the displacement and depend strongly on the perturbation frequencies, especially on the high frequencies. The results, obtained in this work, can be used to construct the boundary conditions for the core dynamics of the long-period oscillations of the Earths fluid outer core.
基金Supported by China Postdoctoral Science Foundation(20100470565)Science and Technology Support Program of Hebei Province(10960408D)+1 种基金Project of Science and technology Bureau of Shijiazhuang(1150093A)Science and Technology Development Project of Qinhuangdao City(201101A182)~~
文摘[Objective] This study aimed to investigate the outer membrane protein （OMP） patterns of Escherichia coli 038, 053 and 075 isolates from chickens. [Method] Eight pathogenic E. coil isolates with various serotypes were used as experimental materials to extract OMP by using supersonic schizolysis method and Sarcosyl. After SDS-PAGE electrophoresis, OMP patterns of the extracted products were determined based on the OMP model diagram. [Result] OMP of eight E. coil isolates with three serotypes were divided into three patterns, to be specific, 2 075 isolates respectively belonged to OMP-I and OMP-II pattern, 1 053 isolate belonged to OMP-II pattern, and 5 038 isolates belonged to OMP-I and OMP-III pattern. [Conclusion] Experimental results showed that E. coli isolates with the same serotype may belong to completely different OMP patterns, while serologically unrelated isolates may belong to the same OMP pattern. OMP of E. coil isolates with the same serotype may generate genetic differentiation; in addition, OMP of E. coli isolates with different serotypes may have different genetic correlation.
基金This work was supported in part by grants from the Department of Science and Technology of Hunan Province (No. 01SSY2008-6) the Department of Health of Hunan Province (No. B2003-078).
文摘Objective: To construct a recombinant plasmid containing the outer membrane protein 2 (Omp2) gene of Chlamydia trachomatis and express Omp2 in E.coli. Methods: The omp2 gene of C. trachomatis serovar D was cloned into pQE30 vector following PCR amplification from genomic DNA. E. coli M15 transformants were induced to express the fusion protein by IPTG and the product was identified by SDS-PAGE and Western blot. Results: Confirmed by enzyme cleavage analysis and DNA sequencing, a correct recombinant plasmid pQE30/omp2 was constructed. The fusion protein from the transformants was approximately 60 kDa in size in SDS-PAGE analysis, which could specially react with anti-6 X His mouse monoclonal IgG antibodies. Conclusion: We successfully expressed Omp2 in E. coli M15, providing an efficient and simple system for assaying the immunological properties of Omp2.
基金Supported by National Natural Science Foundation of China(Grant No51506108)
文摘Semi-floating ring bearing（SFRB） is developed to control the vibration of turbocharger rotor. The outer clearance of SFRB affects the magnitude and frequency of nonlinear whirl motion, which is significant for the design of turbocharger. In order to explore the effects of outer clearance, a transient finite element analysis program for rotor and oil film bearing is built and validated by a published experimental case. The nonlinear dynamic behaviors ofrotor-SFRB system are simulated. According to the simulation results, two representative subsynchronous oscillations excited by the two hearings respectively are discovered. As the outer clearance of SFRB increases from 24 ~tm to 60 pro, the low-frequency subsynchronous oscillation experiences three steps, including a strong start, a gradual recession and a combination with the other one. At the same time, the high-frequency subsynchronous oscillation starts to appear gradually, then strengthens, and finally combines. If gravity and unbalance are neglected, the combination will start starts from high rotor speed and extents to low rotor speed, just like a ＂zipper＂. It is found from the quantitative analysis that when the outer clearance increases, the vibration amplitude experiences large value firstly, then reduction, and suddenly increasing after combination. A useful design principle of SFRB outer clearance for minimum vibration amplitude is proposed： the outer clearance value should be chosen to keep the frequency of two subsynchronous oscillations clearly separated and their amplitudes close.
基金the National Key Research and Development Program of China(Grant No.2017YFC1501601)the Key Program of the Ministry of Science and Technology of China(Grant No.2017YFE0107700)the National Natural Science Foundation of China(Grant Nos.41875054,41730961,41730960,and 41775065).
文摘Idealized numerical simulations are conducted in this study to comparatively investigate the characteristics of the stratiform sector in the outer rainbands of tropical cyclones(TCs)in lower-and upper-layer vertical wind shear(VWS)with moderate magnitude.Consistent with the results in previous studies,the outer rainband stratiform sector of the TCs simulated in both experiments is generally located downshear left.Upper-layer VWS tends to produce stronger asymmetric outflow at upper levels in the downshear-left quadrant than lower-layer shear.This stronger asymmetric outflow transports more water vapor radially outward from the inner core to the outer core at upper levels in the downshear-left quadrant in the upper-layer shear experiment.More depositional growth of both graupel and cloud ice thus occurs downshear left in upper layers in the outer core,yielding more diabatic heating and stronger upward motions,particularly in the stratiformdominated part of the stratiform sector in the upper-layer shear experiment.Resultingly,a better-organized stratiform sector in the outer rainbands is found in the upper-layer VWS experiment than in the lower-layer VWS experiment.The diabatic heating associated with the stratiform sector produces strong midlevel outflow on the radially inward side of,and weak midlevel inflow on the radially outward side of,the heating core,with lower-level inflow beneath the midlevel outflow and upper-level inflow above.The upper-layer VWS tends to produce a deeper asymmetric inflow layer in the outer rainband stratiform sector,with more significant lower-level inflow and tangential jets in the upper-layer VWS experiment.
