The big-tapered profiled ring disk is a key component of engines for rockets and missiles.A new forming technology,as called spinning-rolling process,has been proposed previously for the high performance,high efficien...The big-tapered profiled ring disk is a key component of engines for rockets and missiles.A new forming technology,as called spinning-rolling process,has been proposed previously for the high performance,high efficiency and low-cost manufacturing of the component.Blank design is the key part of plastic forming process design.For spinning-rolling process,the shape and size of the blank play a crucial role in process stability,deformation behavior and dimensional accuracy.So this work proposes a blank design method to determine the geometry structure and sizes of the blank.The mathematical model for calculating the blank size has been deduced based on volume conservation and neutral layer length invariance principle.The FE simulation and corresponding trial production of an actual big-tapered profiled ring disk show that the proposed blank design method is applicative.In order to obtain a preferred blank,the influence rules of blank size determined by different deformation degrees(rolling ratio k)on the spinning-rolling process are revealed by comprehensive FE simulations.Overall considering the process stability,circularity of the deformed ring disk and forming forces,a reasonable range of deformation degree(rolling ratio k)is recommended for the blank design of the new spinning-rolling process.展开更多
Profiled monolayer cBN wheel was induction brazed for grinding of titanium dovetail slot in this study.Aimed at acquiring a uniform temperature distribution along the profiled surface and reducing the thermal deformat...Profiled monolayer cBN wheel was induction brazed for grinding of titanium dovetail slot in this study.Aimed at acquiring a uniform temperature distribution along the profiled surface and reducing the thermal deformation of the brazed wheel,a finite element model was established to investigate the temperature uniformity during induction brazing.A suitable induction coil and the related working parameters were designed and chosen based on the simulation results.Ag-Cu-Ti alloy and cBN grains were applied in the induction brazing experiment.The results showed geometric deformation of the brazed wheel was no more than 0.01 mm and chemical reaction layer were found on the brazed joint interface.Further validation tests were carried out by grinding of Ti-6 Al-4 V alloy.Compared to the electroplated wheel,the brazed wheel showed better performance such as low specific grinding energy and good ground quality in grinding of Ti-6 Al-4 V alloy.Abrasion wear was found to be the main failure mode for the induction brazed wheel,while adhesion and grains pull-out were the main failure mode for the electroplated wheel.展开更多
The most common and abundant DNA modification is 5-methylcytosine（5mC）,which has been well-established as an epigenetic mark regulating gene expression in eukaryotes（Jones,2012）.Another DNA modification N^6-methyl...The most common and abundant DNA modification is 5-methylcytosine（5mC）,which has been well-established as an epigenetic mark regulating gene expression in eukaryotes（Jones,2012）.Another DNA modification N^6-methyldeoxyadenosine（6mA）,previously reported as a widespread DNA methylation in prokaryotes.展开更多
The final quality of complex conical-section rings depends on co-design of multiple processes in forming process chain.In this study,for a complex aeroengine casing ring with a large slope and a flange on its end,a co...The final quality of complex conical-section rings depends on co-design of multiple processes in forming process chain.In this study,for a complex aeroengine casing ring with a large slope and a flange on its end,a co-design method of the forming process chain is put forward towards the objective of precision forming,which not only proposes a standard process route composed of multiple processes of upsetting,punching,rectangular ring rolling,loose tooling forging and profiled ring rolling,but also presents co-design methods of dies and blanks for all the processes.For profiled ring rolling,a design method of preformed blank that makes the blank and the target conical-section ring have the same axial volume distribution is proposed.By the method,the axial metal redistribution during the process can be alleviated greatly thus improving the forming stability and precision of the ring.Based on the geometric features of designed preformed blank,design methods of blanks and dies for loose tolling forging,rectangular ring rolling,punching and upsetting are proposed sequentially.In view of the key roles of loose tooling forging(manufacturing the preformed blank)and profiled ring rolling on the final quality of the conical ring parts,inherited FE simulations for these two processes are performed to verify the proposed design methods and determine appropriate design parameter.It is demonstrated that the proposed design method has significant advantages in improving forming precision.Besides,a suggestive value 1.5 of the rolling ratio for profiled ring rolling(a key design parameter)is given based on comprehensive consideration of multiple indicators such as ring roundness,deformation uniformity and forming load.The corresponding industrial experiments performed illustrate that a high forming precision of the conical-section aeroengine casing ring is achieved.展开更多
An an alytical model based on linear decreasi ng leveli ng scheme was proposed to inv estigate the longitu din ally profiled plate leveling process.Considering the variable cross-sectional thickness of longitudinally ...An an alytical model based on linear decreasi ng leveli ng scheme was proposed to inv estigate the longitu din ally profiled plate leveling process.Considering the variable cross-sectional thickness of longitudinally profiled plate and the dynamic reductions in leveling rolls,the reduction models of upper and lower rolls,the leveling force model and the leveling moment model were established,respectively,based on linear decreasing leveling scheme.Moreover,the finite element model of longitudinally profiled plate leveling process was established based on ABAQUS.Then,the total displacements of upper and lower rolls,the leveling force and the stress distribution of longifudinally profiled plate in the leveling process were calculated.To verify the validity of the proposed models,calculated leveling forces were compared with the measured values,and very good agreements are found.Calculated results show that linear decreasing leveling scheme is suitable for leveling longitudinally profiled plate.展开更多
How to utilize existing flow control mechanisms to make profiled end wall design more flexible,efficient,and physical is a meaningful challenge.This study presents a three-dimensional inverse method for profiled end w...How to utilize existing flow control mechanisms to make profiled end wall design more flexible,efficient,and physical is a meaningful challenge.This study presents a three-dimensional inverse method for profiled end wall design to achieve the application of flow control mechanisms.The predetermined pressure distribution on the end wall is reached by modifying the end wall geometry during flow field calculation.A motion velocity model is derived from the normal momentum equation of the moving no-slip boundary to modify the end wall geometry.A Reynolds-Averaged Navier-Stokes(RANS)solver based on the Semi-Implicit Method for Pressure Linked Equations(SIMPLE)algorithm is adopted to simulate the flow field.Based on the mechanism understanding obtained through numerical optimization results,this study adopts the inverse method to redesign an optimized end wall in a compressor cascade.The results indicate that the redesigned end wall exhibits better loss reduction,reducing the overall total pressure loss by 5.5%,whereas the optimized end wall reduces it by 3%.The inverse method allows the imposition of desired influences on the end wall flow without constructing a database,making it highly flexible,efficient,and physical.展开更多
Considering the variable cross section thickness of longitudinal profiled plate and the dynamic reductions of straightening rolls,an analytical model combining curvature integral method with linear decreasing straight...Considering the variable cross section thickness of longitudinal profiled plate and the dynamic reductions of straightening rolls,an analytical model combining curvature integral method with linear decreasing straightening scheme was proposed to investigate the longitudinal profiled plate straightening process.Moreover,the calculation flow and solution algorithm of longitudinal profiled plate straightening process were presented.To verify the proposed model,calculated straightening forces were compared with the measured values,and very good agreements were achieved.Then,the reduction,contact angle,reverse bending curvature,residual curvature,straightening force and straightening moment of longitudinal profiled plate in the straightening process were calculated and analyzed,and the calculated results show that the curvature integral method can be used to reveal the mechanism of longitudinal profiled plate straightening.展开更多
A multi-shape representation approach for measuring geometrical properties of profiled fibers was presented.From closed edge chains of a fiber cross section,three evenly spaced vertices were selected to form a triangl...A multi-shape representation approach for measuring geometrical properties of profiled fibers was presented.From closed edge chains of a fiber cross section,three evenly spaced vertices were selected to form a triangle by changing the vertices' spacing,or the step length,the Triangle Area Representation(TAR)was calculated with a special determinant.The bend direction of the two consecutive lines drawn by three vertices determined the sign of the TAR.TARN and TARP were negative and positive extensions of TAR,and used to analyze concave and convex segments on the boundary.The length of TARN measured the size of concaveness.Multi-scale TARPs together with TARN can help to detect fiber conglutinations.展开更多
The key technique of a kinetic energy rod(KER) warhead is to control the flight attitude of rods. The rods are usually designed to different shapes. A new conceptual KER named profiled rod which has large L/D ratio is...The key technique of a kinetic energy rod(KER) warhead is to control the flight attitude of rods. The rods are usually designed to different shapes. A new conceptual KER named profiled rod which has large L/D ratio is described in this paper. The elastic dynamic equations of this profiled rod flying at high velocity after detonation are set up on the basis of Euler-Bernoulli beam, and the aeroelastic deformation of profiled rod is calculated by semi-analytical method for calculating the vibration characteristics of variable cross-section beam. In addition, the aeroelastic deformation of the undeformed profiled rod and the aeroelastic deformation of deformed profiled rod which is caused by the detonation of explosive are simulated by computational fluid dynamic and finite element method(CFD/FEM), respectively. A satisfactory agreement of these two methods is obtained by the comparison of two methods. The results show that the semi-analytical method for calculating the vibration characteristics of variable cross-section beam is applied to analyze the aeroelastic deformation of profiled rod flying at high velocity.展开更多
Longitude profiled cladded sheet is obtained by rolling bimetal cladded sheet with variable gauge rolling technology.The longitude profiled rolling process of Cu/Al cladded sheets was studied by finite element method ...Longitude profiled cladded sheet is obtained by rolling bimetal cladded sheet with variable gauge rolling technology.The longitude profiled rolling process of Cu/Al cladded sheets was studied by finite element method and experiments.The rolling force rises with the increase in reduction,and a sudden change appears at the end of the thickness variation zone.The thickness ratio of copper layer is enlarged after rolling owing to its relatively large deformation resistance and continues to rise with the increase in reduction rate.Lower elongation of copper side leads to the warpage of exit metal to copper side,which further hinders the deformation of copper.The influence of asymmetric rolling parameters indicates that increasing the work roll diameter ratio,speed radio,and friction coefficient on Al side can reduce the warpage when the reduction rate is below a certain value depending on the thickness ratio and other rolling parameters.Comparison of experiments and simulation results showed good agreement and verified the finite element model.展开更多
A new Kinetic Energy Rod( KER) warhead named profiled rod warhead is proposed in this paper.Based on the design of profiled rod warhead,a model of profiled rod driven by detonation is established. The detonation proce...A new Kinetic Energy Rod( KER) warhead named profiled rod warhead is proposed in this paper.Based on the design of profiled rod warhead,a model of profiled rod driven by detonation is established. The detonation process is simulated by ANSYS / LS-DYNA,and the deployment velocity and initial flight attitude of rod are achieved. In addition,static rod deployment testing are performed to investigate the damage effect,the spatial flight attitude and deployment velocity. A satisfactory agreement is obtained by the comparison between numerical results and testing results. Meanwhile,the profiled rod studies are conducted to determine a higher penetrability compared with traditional cylindrical rods. Rigid body dynamics equations of profiled rod,which accounts for the influence of air resistance,are set up to predict the flight trajectory of long-distance. The results show that the profiled rod may provide a better penetration angle which still maintains a significant penetrability against projectiles when the rods move off long-distance range.展开更多
In order to achieve a lower consumed energy, the performance of a new type of rotating volumetric pump with two profiled rotors (variant I) which is compared with a centrifugal pump (variant II) is presented. The...In order to achieve a lower consumed energy, the performance of a new type of rotating volumetric pump with two profiled rotors (variant I) which is compared with a centrifugal pump (variant II) is presented. The analysis regarding the same flow rate of transported liquid and the same pressure increases points out the conduct of the system at the variation of the key operating parameters. The actual driving power of the rotating volumetric pump is higher stating that is more advantageous in operation. The effective efficiency of the system is improved due to the original constructive solution.展开更多
Composite slabs with profiled steel sheet are widely applied in practical structures now. Plenty of literatures can be available about simply supported composite slabs with single span. However, continuous slabs alway...Composite slabs with profiled steel sheet are widely applied in practical structures now. Plenty of literatures can be available about simply supported composite slabs with single span. However, continuous slabs always exist in high-rise building structures. In order to obtain the ultimate loading capacity of continuous composite slabs, the full scale test on slab specimens with high cost need to be carried out. This paper presented an analytical model for calculating the ultimate loading capacity of continuous composite slabs. Only the small-scale slide block test needed to be carried out for determining some mechanical parameters, resulting in less cost, compared with the conventional m-k test method. Various load conditions and parameters were considered in the analytical model. The comparison between test results and predicted results showed that the proposed method had enough precision. Furthermore, the simplified method was also proposed for practical design.展开更多
Accurate retrieval of atmospheric vertical profiles is critical for improving weather prediction and climate monitoring.However,the complexity of atmospheric processes in cloudy regions poses challenges compared to th...Accurate retrieval of atmospheric vertical profiles is critical for improving weather prediction and climate monitoring.However,the complexity of atmospheric processes in cloudy regions poses challenges compared to those of clear sky scenarios.This study presents a novel framework that integrates Bayesian optimization and machine learning approaches to retrieve atmospheric vertical profiles—including temperature,humidity,ozone concentration,cloud fraction,ice water content(IWC),and liquid water content(LWC)—from hyperspectral infrared observations.Specifically,a Bayesian method was used to refine ERA5 reanalysis data by minimizing brightness temperature(BT)discrepancies against FY-4B Geostationary Interferometric Infrared Sounder(GIIRS)observations,generating a high-quality profile database(~2.8 million profiles)across diverse weather systems.The optimized profiles improve radiative consistency,reducing BT biases from>40 K to<10 K in cloudy regions.To further overcome the limitations of the Bayesian method,we developed a Transformer-Resnet hybrid model(TERNet),which achieved superior performance with RMSE values of 1.61 K(temperature),5.77%(humidity),and 2.25×10^(–6)/6.09×10^(–6)kg kg^(–1)(IWC/LWC)across the entire vertical levels in all-sky conditions.The TERNet outperforms both ERA5 in cloud parameter retrieval and the GIIRS L2 product in thermodynamic profiling.Independent verification with radiosonde and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations(CALIPSO)datasets confirms the framework's reliability across various meteorological regimes.This work demonstrates the capability of combining physics-informed Bayesian methods with data-driven machine learning to fully exploit hyperspectral IR data.展开更多
Introduction:Advances in HIV management have transformed HIV into a chronic condition,resulting in improved prognosis and increased survival among people living with HIV(PLWH).Traditional risk factors for metabolic dy...Introduction:Advances in HIV management have transformed HIV into a chronic condition,resulting in improved prognosis and increased survival among people living with HIV(PLWH).Traditional risk factors for metabolic dysfunction-associated steatotic liver disease(MASLD)—including dyslipidemia—are prevalent in PLWH.This systematic review and meta-analysis aim to synthesize current evidence on lipid profile disturbances as contributors to MASLD in PLWH.Methods:This systematic review and meta-analysis were conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA)guidelines and registered in PROSPERO with registration number CRD420251054477.We searched seven databases to identify studies reporting the prevalence and characteristics of MASLD in PLWH.Meta-analysis was conducted using Review Manager 5.4.1.Mean differences(MDs)were calculated using a random-effects model.Risk of bias was assessed using the ROBINS-E tool.Results:A total of 17 studies comprising 3933 HIV-positive participants were included,among whom 1226(37%)had MASLD.Male sex was significantly associated with MASLD(OR=1.57;95%CI:1.13-2.17;p=0.007).MASLD was significantly associated with higher body mass index(BMI)(MD=3.23 kg/m^(2);p<0.00001).Lipid profile analysis revealed that MASLD patients had higher total cholesterol(MD=6.62 mg/dL;p=0.01),low density lipoprotein(LDL)(MD=3.83 mg/dL;p=0.01),triglycerides(MD=63.02 mg/dL;p<0.00001),and lower high density lipoprotein(HDL)(MD=-3.73 mg/dL;p<0.0001).Conclusion:This study demonstrates a significant difference in lipid profiles(higher total cholesterol,LDL,triglycerides,and lower HDL)among PLWH who develop MASLD,suggesting a potential metabolic signature associated with this comorbidity.展开更多
The study evaluated the skin anti-aging activity of Astragalus sarcocolla leaves extract(ASE)by assessing its antioxidant and inhibitory effect activity on matrix metalloproteinase(MMP),collagenase,elastase,hyaluronid...The study evaluated the skin anti-aging activity of Astragalus sarcocolla leaves extract(ASE)by assessing its antioxidant and inhibitory effect activity on matrix metalloproteinase(MMP),collagenase,elastase,hyaluronidase,and tyrosinase in relation to its chemical composition.Ultra Performance Liquid Chromatography-Mass Spectrometry(UPLC-MS)identified 27 metabolites(15 flavonoids,8 phenolic acids and their derivatives,and 4 coumarins).ASE showed strong antioxidant capacity in DPPH(IC_(50)value of 26.05μg/mL)and FRAP(2433μM FeSO_(4)/g extract)assays.The extract inhibited MMP-1 and MMP-9 in a concentration-dependent manner and suppressed collagenase,elastase,hyaluronidase,and tyrosinase activities(IC_(50)=35.038,40.748,61.389,and 30.980μg/mL,respectively).A network pharmacology study was conducted to uncover the mechanisms responsible for skin anti-aging effects,and molecular docking further evaluated interactions of key metabolites with hub targets.Twenty-one bioactive metabolites,selected based on oral bioavailability and drug-likeness,highlighted cinnamic acid,acacetin,luteolin,kaempferol,and apigenin as key compounds.MMP-9,ESR1,PTGS-2,and EGFR were identified as main targets.Docking studies revealed that acacetin and apigenin have stronger binding affinities to MMP-9,PTGS-2,and EGFR than other constituents.These findings suggest that ASE may serve as a natural multi-target skin anti-aging remedy with potential cosmetic applications.展开更多
Chamaedorea seifrizii is a bamboo plant that is mainly used for its air-purifying properties and ornamental value.Due to the scarcity of reports on its phytochemical constitutes,this study was aimed at chemical profil...Chamaedorea seifrizii is a bamboo plant that is mainly used for its air-purifying properties and ornamental value.Due to the scarcity of reports on its phytochemical constitutes,this study was aimed at chemical profiling,phytochemical analysis and evaluation of its in-vitro biological activities of acetone extracts of auxiliary inflorescence and fruits of Chamaedorea seifrizii accompanied by in-silico analysis.Standard techniques were employed for phytochemical screening of phenolics,flavonoids and tannins and anti-oxidant and anti-inflammatory tests.In-silico analysis coupled with molecular dynamics simulation was also conducted to find out interaction of some components to inflammatory responses.Bioactive compounds in auxiliary inflorescence and fruit extracts were studied using a gas chromatography-flame ionization detector(GC-FID).Numerous antioxidant tests were carried out,including those for 2,2-diphenyl-1-picrylhydrazyl(DPPH),hydroxyl radicals,and nitric oxide radicals and shown that all both extracts depicted exorbitant levels of activities with values ranging from 48 to 96%.Results of GC-FID revealed maximum 18-22 constituents in acetone fractions with phenethyl cinnamate and hinokione as predominant components in auxiliary inflorescence and fruits,respectively.In addition,a strong anti-inflammatory activity was observed with acetone containing extracts.In-silico analysis validated the interaction of phytocomponents to inflammation initiation enzymes.Phytochemicals found in Chamaedorea seifrizii extracts may have pharmacological,antioxidant and anti-inflammatory properties.Chamaedorea seifrizii may be used in this study to produce new herbal remedies for a range of illnesses,perhaps resulting in the development of novel drugs.展开更多
The protein corona formation has been reported to influence the liposomes’behavioral performance in vivo.Accordingly,the effect of physiologically relevant inorganic ion pairs(sodium chloride,sodium sulfate,magnesium...The protein corona formation has been reported to influence the liposomes’behavioral performance in vivo.Accordingly,the effect of physiologically relevant inorganic ion pairs(sodium chloride,sodium sulfate,magnesium chloride,and magnesium sulfate)was investigated.Bovine serum albumin(BSA)was selected as the model protein.Parameters including particle size and zeta potential were assessed,while various spectroscopic techniques were utilized to elucidate the changes in BSA during its interaction with liposomes.The particle size and light intensity distribution changes indicated that the introduction of inorganic pairs,especially the metal cations,could significantly influence both the adsorption of BSA and the aggregation of particles.Furthermore,spectral characterization elucidated that BSA exhibited more extended peptide chains with enhanced exposure to hydrophobic acid amino residues upon adding ion pairs.Electrostatic adsorption and chelation insertion were proposed as metal ion binding modes and the corresponding BSA corona formation.In the electrostatic adsorption mode,sodium ions can enhance the electrostatic interactions,facilitating the“connection”between BSA and liposomes.Magnesium ions can induce stronger hydrophobic interactions through chelation,effectively“drag”BSA segments into the lipid bilayer.This work highlighted important physiological factors for protein-liposome interaction and provided rational model constructions to lay the foundation for further relevant studies.展开更多
Head-splitting is a prevalent physiological disorder in cabbage that causes substantial economic losses.However,the genetic factors and molecular mechanisms underlying head-splitting resistance remain largely unexplor...Head-splitting is a prevalent physiological disorder in cabbage that causes substantial economic losses.However,the genetic factors and molecular mechanisms underlying head-splitting resistance remain largely unexplored.This study identified a genomic region(q NLQ3.1) for head-splitting resistance on chromosome C03 through the combination of QTLseq and GPS analysis in an F_(2) population derived from hybridizing two cabbage inbred lines,‘Dazhengfu'(ZF,susceptible) and ‘103'(resistant).Traditional genetic linkage analysis narrowed q NLQ3.1 to a 74.6 kb region.Furthermore,comparative analysis of the two parental lines using transcriptomic and metabolic profiling demonstrated the crucial role of hormones in regulating head-splitting resistance.Bol028000,encoding a homologue of Arabidopsis Cytokinin Response Factor 3(CRF3),emerged as a promising candidate for head-splitting resistance and was subsequently validated through Sanger sequencing and quantitative RT-PCR(qRT-PCR).Subcellular localisation analysis revealed that Bol028000 was mainly expressed in the nucleus.Additionally,one kompetitive allele-specific PCR(KASP) marker from Bol028000 was developed and utilized to screen 42 inbred lines.These findings enhance the theoretical understanding of head-splitting resistance and provide valuable insights for the molecular breeding of head-splitting resistant cabbages.展开更多
Background:Exposure to environmental vulnerability poses significant threats to adolescent suicidal ideation,while individual resilience can mitigate these adverse effects with notable gender commonalities and differe...Background:Exposure to environmental vulnerability poses significant threats to adolescent suicidal ideation,while individual resilience can mitigate these adverse effects with notable gender commonalities and differences.However,research examining how these factors co-configure at the individual level remains limited,particularly from a gender-specific perspective.Thus,the present study aims to adopt a person-centered analytic approach to identify gender-specific configurations of environmental vulnerability and individual resilience associated with suicidal ideation among Chinese adolescents.Methods:Data were collected from 2616 Chinese primary and secondary school students(aged 10–17;1223 girls).Participants completed validated scales measuring environmental vulnerability,individual resilience,and suicidal ideation.Latent profile analysis(LPA)was conducted separately by gender.Results:Gender differences were prominent:males exhibited higher resilience and lower suicidal ideation,while females reported higher environmental vulnerability and elevated levels of suicidal ideation.LPA identified three distinct profiles for males:Low Vulnerable–High Protective–Low Risk(LHL),Medium Vulnerable–Low Protective–Low Risk(MLL),and High Vulnerable–Low Protective–High Risk(HLH).Four profiles emerged for females:LHL,MLL,Medium Vulnerable–Low Protective–Medium Risk(MLM),and HLH.Crucially,within the HLH profile,males exhibited particularly deficient humor(η^(2)=0.19)and confidence(η^(2)=0.16),while females formed a distinct subgroup characterized by severe academic and family stressors(η^(2)=0.30–0.36).Conclusion:The study underscores developing gender-specific mental health interventions using a nuanced,person-centered approach that considers both environmental risk and individual resilience factors,which allows for targeted suicide prevention strategies addressing the unique needs of male and female adolescents.展开更多
基金the National Natural Science Foundation of China(No.52275378)the National Key Laboratory for Precision Hot Processing of Metals(6142909200208)。
文摘The big-tapered profiled ring disk is a key component of engines for rockets and missiles.A new forming technology,as called spinning-rolling process,has been proposed previously for the high performance,high efficiency and low-cost manufacturing of the component.Blank design is the key part of plastic forming process design.For spinning-rolling process,the shape and size of the blank play a crucial role in process stability,deformation behavior and dimensional accuracy.So this work proposes a blank design method to determine the geometry structure and sizes of the blank.The mathematical model for calculating the blank size has been deduced based on volume conservation and neutral layer length invariance principle.The FE simulation and corresponding trial production of an actual big-tapered profiled ring disk show that the proposed blank design method is applicative.In order to obtain a preferred blank,the influence rules of blank size determined by different deformation degrees(rolling ratio k)on the spinning-rolling process are revealed by comprehensive FE simulations.Overall considering the process stability,circularity of the deformed ring disk and forming forces,a reasonable range of deformation degree(rolling ratio k)is recommended for the blank design of the new spinning-rolling process.
基金the National Natural Science Foundation of China(Nos.51905234,51805231,51975264,51905275,51705463)。
文摘Profiled monolayer cBN wheel was induction brazed for grinding of titanium dovetail slot in this study.Aimed at acquiring a uniform temperature distribution along the profiled surface and reducing the thermal deformation of the brazed wheel,a finite element model was established to investigate the temperature uniformity during induction brazing.A suitable induction coil and the related working parameters were designed and chosen based on the simulation results.Ag-Cu-Ti alloy and cBN grains were applied in the induction brazing experiment.The results showed geometric deformation of the brazed wheel was no more than 0.01 mm and chemical reaction layer were found on the brazed joint interface.Further validation tests were carried out by grinding of Ti-6 Al-4 V alloy.Compared to the electroplated wheel,the brazed wheel showed better performance such as low specific grinding energy and good ground quality in grinding of Ti-6 Al-4 V alloy.Abrasion wear was found to be the main failure mode for the induction brazed wheel,while adhesion and grains pull-out were the main failure mode for the electroplated wheel.
基金supported by Recruitment program of Global Youth Expert of China (to X.G.)the Elite Youth Program of the Chinese Academy of Agricultural Science (to X.G.)the intramural research support from Biotechnology Research Institute, Chinese Academy of Agricultural Sciences
文摘The most common and abundant DNA modification is 5-methylcytosine（5mC）,which has been well-established as an epigenetic mark regulating gene expression in eukaryotes（Jones,2012）.Another DNA modification N^6-methyldeoxyadenosine（6mA）,previously reported as a widespread DNA methylation in prokaryotes.
基金the National Natural Science Foundation of China(52275378).
文摘The final quality of complex conical-section rings depends on co-design of multiple processes in forming process chain.In this study,for a complex aeroengine casing ring with a large slope and a flange on its end,a co-design method of the forming process chain is put forward towards the objective of precision forming,which not only proposes a standard process route composed of multiple processes of upsetting,punching,rectangular ring rolling,loose tooling forging and profiled ring rolling,but also presents co-design methods of dies and blanks for all the processes.For profiled ring rolling,a design method of preformed blank that makes the blank and the target conical-section ring have the same axial volume distribution is proposed.By the method,the axial metal redistribution during the process can be alleviated greatly thus improving the forming stability and precision of the ring.Based on the geometric features of designed preformed blank,design methods of blanks and dies for loose tolling forging,rectangular ring rolling,punching and upsetting are proposed sequentially.In view of the key roles of loose tooling forging(manufacturing the preformed blank)and profiled ring rolling on the final quality of the conical ring parts,inherited FE simulations for these two processes are performed to verify the proposed design methods and determine appropriate design parameter.It is demonstrated that the proposed design method has significant advantages in improving forming precision.Besides,a suggestive value 1.5 of the rolling ratio for profiled ring rolling(a key design parameter)is given based on comprehensive consideration of multiple indicators such as ring roundness,deformation uniformity and forming load.The corresponding industrial experiments performed illustrate that a high forming precision of the conical-section aeroengine casing ring is achieved.
基金Key R&D Program of China(No.20I7YFB0306404)Natural Science Foundation of Hebei Province(No.E2016203179)Postdoctoral Science Foundation of China(No.2016M590211).
文摘An an alytical model based on linear decreasi ng leveli ng scheme was proposed to inv estigate the longitu din ally profiled plate leveling process.Considering the variable cross-sectional thickness of longitudinally profiled plate and the dynamic reductions in leveling rolls,the reduction models of upper and lower rolls,the leveling force model and the leveling moment model were established,respectively,based on linear decreasing leveling scheme.Moreover,the finite element model of longitudinally profiled plate leveling process was established based on ABAQUS.Then,the total displacements of upper and lower rolls,the leveling force and the stress distribution of longifudinally profiled plate in the leveling process were calculated.To verify the validity of the proposed models,calculated leveling forces were compared with the measured values,and very good agreements are found.Calculated results show that linear decreasing leveling scheme is suitable for leveling longitudinally profiled plate.
基金Supported by the National Natural Science Foundation of China(No.52376021).
文摘How to utilize existing flow control mechanisms to make profiled end wall design more flexible,efficient,and physical is a meaningful challenge.This study presents a three-dimensional inverse method for profiled end wall design to achieve the application of flow control mechanisms.The predetermined pressure distribution on the end wall is reached by modifying the end wall geometry during flow field calculation.A motion velocity model is derived from the normal momentum equation of the moving no-slip boundary to modify the end wall geometry.A Reynolds-Averaged Navier-Stokes(RANS)solver based on the Semi-Implicit Method for Pressure Linked Equations(SIMPLE)algorithm is adopted to simulate the flow field.Based on the mechanism understanding obtained through numerical optimization results,this study adopts the inverse method to redesign an optimized end wall in a compressor cascade.The results indicate that the redesigned end wall exhibits better loss reduction,reducing the overall total pressure loss by 5.5%,whereas the optimized end wall reduces it by 3%.The inverse method allows the imposition of desired influences on the end wall flow without constructing a database,making it highly flexible,efficient,and physical.
基金The authors are grateful for the supports of the National Key Research and Development Program of China(No.2017YFB0306404)Key Project of Hebei Education Department(No.ZD2018203).
文摘Considering the variable cross section thickness of longitudinal profiled plate and the dynamic reductions of straightening rolls,an analytical model combining curvature integral method with linear decreasing straightening scheme was proposed to investigate the longitudinal profiled plate straightening process.Moreover,the calculation flow and solution algorithm of longitudinal profiled plate straightening process were presented.To verify the proposed model,calculated straightening forces were compared with the measured values,and very good agreements were achieved.Then,the reduction,contact angle,reverse bending curvature,residual curvature,straightening force and straightening moment of longitudinal profiled plate in the straightening process were calculated and analyzed,and the calculated results show that the curvature integral method can be used to reveal the mechanism of longitudinal profiled plate straightening.
基金Foundation for the Author of National Excellent Doctoral Dissertation of P.R.China(No.200350)
文摘A multi-shape representation approach for measuring geometrical properties of profiled fibers was presented.From closed edge chains of a fiber cross section,three evenly spaced vertices were selected to form a triangle by changing the vertices' spacing,or the step length,the Triangle Area Representation(TAR)was calculated with a special determinant.The bend direction of the two consecutive lines drawn by three vertices determined the sign of the TAR.TARN and TARP were negative and positive extensions of TAR,and used to analyze concave and convex segments on the boundary.The length of TARN measured the size of concaveness.Multi-scale TARPs together with TARN can help to detect fiber conglutinations.
文摘The key technique of a kinetic energy rod(KER) warhead is to control the flight attitude of rods. The rods are usually designed to different shapes. A new conceptual KER named profiled rod which has large L/D ratio is described in this paper. The elastic dynamic equations of this profiled rod flying at high velocity after detonation are set up on the basis of Euler-Bernoulli beam, and the aeroelastic deformation of profiled rod is calculated by semi-analytical method for calculating the vibration characteristics of variable cross-section beam. In addition, the aeroelastic deformation of the undeformed profiled rod and the aeroelastic deformation of deformed profiled rod which is caused by the detonation of explosive are simulated by computational fluid dynamic and finite element method(CFD/FEM), respectively. A satisfactory agreement of these two methods is obtained by the comparison of two methods. The results show that the semi-analytical method for calculating the vibration characteristics of variable cross-section beam is applied to analyze the aeroelastic deformation of profiled rod flying at high velocity.
基金The research was financially supported by the National Natural Science Foundation of China(Grant Nos.51674222 and 51974278)Yanshan University(15LGAOO3).
文摘Longitude profiled cladded sheet is obtained by rolling bimetal cladded sheet with variable gauge rolling technology.The longitude profiled rolling process of Cu/Al cladded sheets was studied by finite element method and experiments.The rolling force rises with the increase in reduction,and a sudden change appears at the end of the thickness variation zone.The thickness ratio of copper layer is enlarged after rolling owing to its relatively large deformation resistance and continues to rise with the increase in reduction rate.Lower elongation of copper side leads to the warpage of exit metal to copper side,which further hinders the deformation of copper.The influence of asymmetric rolling parameters indicates that increasing the work roll diameter ratio,speed radio,and friction coefficient on Al side can reduce the warpage when the reduction rate is below a certain value depending on the thickness ratio and other rolling parameters.Comparison of experiments and simulation results showed good agreement and verified the finite element model.
基金Sponsored by the CALT University Joint Fund(Grant No.CALT201105)
文摘A new Kinetic Energy Rod( KER) warhead named profiled rod warhead is proposed in this paper.Based on the design of profiled rod warhead,a model of profiled rod driven by detonation is established. The detonation process is simulated by ANSYS / LS-DYNA,and the deployment velocity and initial flight attitude of rod are achieved. In addition,static rod deployment testing are performed to investigate the damage effect,the spatial flight attitude and deployment velocity. A satisfactory agreement is obtained by the comparison between numerical results and testing results. Meanwhile,the profiled rod studies are conducted to determine a higher penetrability compared with traditional cylindrical rods. Rigid body dynamics equations of profiled rod,which accounts for the influence of air resistance,are set up to predict the flight trajectory of long-distance. The results show that the profiled rod may provide a better penetration angle which still maintains a significant penetrability against projectiles when the rods move off long-distance range.
文摘In order to achieve a lower consumed energy, the performance of a new type of rotating volumetric pump with two profiled rotors (variant I) which is compared with a centrifugal pump (variant II) is presented. The analysis regarding the same flow rate of transported liquid and the same pressure increases points out the conduct of the system at the variation of the key operating parameters. The actual driving power of the rotating volumetric pump is higher stating that is more advantageous in operation. The effective efficiency of the system is improved due to the original constructive solution.
文摘Composite slabs with profiled steel sheet are widely applied in practical structures now. Plenty of literatures can be available about simply supported composite slabs with single span. However, continuous slabs always exist in high-rise building structures. In order to obtain the ultimate loading capacity of continuous composite slabs, the full scale test on slab specimens with high cost need to be carried out. This paper presented an analytical model for calculating the ultimate loading capacity of continuous composite slabs. Only the small-scale slide block test needed to be carried out for determining some mechanical parameters, resulting in less cost, compared with the conventional m-k test method. Various load conditions and parameters were considered in the analytical model. The comparison between test results and predicted results showed that the proposed method had enough precision. Furthermore, the simplified method was also proposed for practical design.
基金supported by the National Natural Science Foundation of China under Grant U2442219Fengyun Satellite Application Pioneer Program(2023)Special Initiative on Numerical Weather Prediction(NWP)Applications,the Civil Aerospace Technology Pre-Research Project(D040405)the Joint Funds of the Zhejiang Provincial Natural Science Foundation of China under Grant No.LZJMZ23D050003。
文摘Accurate retrieval of atmospheric vertical profiles is critical for improving weather prediction and climate monitoring.However,the complexity of atmospheric processes in cloudy regions poses challenges compared to those of clear sky scenarios.This study presents a novel framework that integrates Bayesian optimization and machine learning approaches to retrieve atmospheric vertical profiles—including temperature,humidity,ozone concentration,cloud fraction,ice water content(IWC),and liquid water content(LWC)—from hyperspectral infrared observations.Specifically,a Bayesian method was used to refine ERA5 reanalysis data by minimizing brightness temperature(BT)discrepancies against FY-4B Geostationary Interferometric Infrared Sounder(GIIRS)observations,generating a high-quality profile database(~2.8 million profiles)across diverse weather systems.The optimized profiles improve radiative consistency,reducing BT biases from>40 K to<10 K in cloudy regions.To further overcome the limitations of the Bayesian method,we developed a Transformer-Resnet hybrid model(TERNet),which achieved superior performance with RMSE values of 1.61 K(temperature),5.77%(humidity),and 2.25×10^(–6)/6.09×10^(–6)kg kg^(–1)(IWC/LWC)across the entire vertical levels in all-sky conditions.The TERNet outperforms both ERA5 in cloud parameter retrieval and the GIIRS L2 product in thermodynamic profiling.Independent verification with radiosonde and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations(CALIPSO)datasets confirms the framework's reliability across various meteorological regimes.This work demonstrates the capability of combining physics-informed Bayesian methods with data-driven machine learning to fully exploit hyperspectral IR data.
文摘Introduction:Advances in HIV management have transformed HIV into a chronic condition,resulting in improved prognosis and increased survival among people living with HIV(PLWH).Traditional risk factors for metabolic dysfunction-associated steatotic liver disease(MASLD)—including dyslipidemia—are prevalent in PLWH.This systematic review and meta-analysis aim to synthesize current evidence on lipid profile disturbances as contributors to MASLD in PLWH.Methods:This systematic review and meta-analysis were conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA)guidelines and registered in PROSPERO with registration number CRD420251054477.We searched seven databases to identify studies reporting the prevalence and characteristics of MASLD in PLWH.Meta-analysis was conducted using Review Manager 5.4.1.Mean differences(MDs)were calculated using a random-effects model.Risk of bias was assessed using the ROBINS-E tool.Results:A total of 17 studies comprising 3933 HIV-positive participants were included,among whom 1226(37%)had MASLD.Male sex was significantly associated with MASLD(OR=1.57;95%CI:1.13-2.17;p=0.007).MASLD was significantly associated with higher body mass index(BMI)(MD=3.23 kg/m^(2);p<0.00001).Lipid profile analysis revealed that MASLD patients had higher total cholesterol(MD=6.62 mg/dL;p=0.01),low density lipoprotein(LDL)(MD=3.83 mg/dL;p=0.01),triglycerides(MD=63.02 mg/dL;p<0.00001),and lower high density lipoprotein(HDL)(MD=-3.73 mg/dL;p<0.0001).Conclusion:This study demonstrates a significant difference in lipid profiles(higher total cholesterol,LDL,triglycerides,and lower HDL)among PLWH who develop MASLD,suggesting a potential metabolic signature associated with this comorbidity.
基金funded by the Deanship of Graduate Studies and Scientific Research at Jouf University under grant No.(DGSSR-2023-01-02126).
文摘The study evaluated the skin anti-aging activity of Astragalus sarcocolla leaves extract(ASE)by assessing its antioxidant and inhibitory effect activity on matrix metalloproteinase(MMP),collagenase,elastase,hyaluronidase,and tyrosinase in relation to its chemical composition.Ultra Performance Liquid Chromatography-Mass Spectrometry(UPLC-MS)identified 27 metabolites(15 flavonoids,8 phenolic acids and their derivatives,and 4 coumarins).ASE showed strong antioxidant capacity in DPPH(IC_(50)value of 26.05μg/mL)and FRAP(2433μM FeSO_(4)/g extract)assays.The extract inhibited MMP-1 and MMP-9 in a concentration-dependent manner and suppressed collagenase,elastase,hyaluronidase,and tyrosinase activities(IC_(50)=35.038,40.748,61.389,and 30.980μg/mL,respectively).A network pharmacology study was conducted to uncover the mechanisms responsible for skin anti-aging effects,and molecular docking further evaluated interactions of key metabolites with hub targets.Twenty-one bioactive metabolites,selected based on oral bioavailability and drug-likeness,highlighted cinnamic acid,acacetin,luteolin,kaempferol,and apigenin as key compounds.MMP-9,ESR1,PTGS-2,and EGFR were identified as main targets.Docking studies revealed that acacetin and apigenin have stronger binding affinities to MMP-9,PTGS-2,and EGFR than other constituents.These findings suggest that ASE may serve as a natural multi-target skin anti-aging remedy with potential cosmetic applications.
基金Dept of Science and Technology,Govt.of India,DST/SEED/SCSP/STI/2019/253.
文摘Chamaedorea seifrizii is a bamboo plant that is mainly used for its air-purifying properties and ornamental value.Due to the scarcity of reports on its phytochemical constitutes,this study was aimed at chemical profiling,phytochemical analysis and evaluation of its in-vitro biological activities of acetone extracts of auxiliary inflorescence and fruits of Chamaedorea seifrizii accompanied by in-silico analysis.Standard techniques were employed for phytochemical screening of phenolics,flavonoids and tannins and anti-oxidant and anti-inflammatory tests.In-silico analysis coupled with molecular dynamics simulation was also conducted to find out interaction of some components to inflammatory responses.Bioactive compounds in auxiliary inflorescence and fruit extracts were studied using a gas chromatography-flame ionization detector(GC-FID).Numerous antioxidant tests were carried out,including those for 2,2-diphenyl-1-picrylhydrazyl(DPPH),hydroxyl radicals,and nitric oxide radicals and shown that all both extracts depicted exorbitant levels of activities with values ranging from 48 to 96%.Results of GC-FID revealed maximum 18-22 constituents in acetone fractions with phenethyl cinnamate and hinokione as predominant components in auxiliary inflorescence and fruits,respectively.In addition,a strong anti-inflammatory activity was observed with acetone containing extracts.In-silico analysis validated the interaction of phytocomponents to inflammation initiation enzymes.Phytochemicals found in Chamaedorea seifrizii extracts may have pharmacological,antioxidant and anti-inflammatory properties.Chamaedorea seifrizii may be used in this study to produce new herbal remedies for a range of illnesses,perhaps resulting in the development of novel drugs.
基金supported by the National Natural Science Foundation of China(No.82373800)Guangdong Basic and Applied Basic Research Foundation(No.2024A1515011236)Continuation Project of Excellent Doctors,Guangzhou Basic and Applied Basic Research Foundation(No.2025A04J5082).
文摘The protein corona formation has been reported to influence the liposomes’behavioral performance in vivo.Accordingly,the effect of physiologically relevant inorganic ion pairs(sodium chloride,sodium sulfate,magnesium chloride,and magnesium sulfate)was investigated.Bovine serum albumin(BSA)was selected as the model protein.Parameters including particle size and zeta potential were assessed,while various spectroscopic techniques were utilized to elucidate the changes in BSA during its interaction with liposomes.The particle size and light intensity distribution changes indicated that the introduction of inorganic pairs,especially the metal cations,could significantly influence both the adsorption of BSA and the aggregation of particles.Furthermore,spectral characterization elucidated that BSA exhibited more extended peptide chains with enhanced exposure to hydrophobic acid amino residues upon adding ion pairs.Electrostatic adsorption and chelation insertion were proposed as metal ion binding modes and the corresponding BSA corona formation.In the electrostatic adsorption mode,sodium ions can enhance the electrostatic interactions,facilitating the“connection”between BSA and liposomes.Magnesium ions can induce stronger hydrophobic interactions through chelation,effectively“drag”BSA segments into the lipid bilayer.This work highlighted important physiological factors for protein-liposome interaction and provided rational model constructions to lay the foundation for further relevant studies.
基金funded by the Agricultural Development Program through Science and Technology of Shanghai,China (2022-02-08-00-12-F01099)the National Key R&D Program of China (2023YFD1201501)+1 种基金the Science and Technology Commission of Shanghai Municipality,China (22DX1900100)the Excellent Team Project of Shanghai Academy of Agricultural Sciences,China (2022(007))。
文摘Head-splitting is a prevalent physiological disorder in cabbage that causes substantial economic losses.However,the genetic factors and molecular mechanisms underlying head-splitting resistance remain largely unexplored.This study identified a genomic region(q NLQ3.1) for head-splitting resistance on chromosome C03 through the combination of QTLseq and GPS analysis in an F_(2) population derived from hybridizing two cabbage inbred lines,‘Dazhengfu'(ZF,susceptible) and ‘103'(resistant).Traditional genetic linkage analysis narrowed q NLQ3.1 to a 74.6 kb region.Furthermore,comparative analysis of the two parental lines using transcriptomic and metabolic profiling demonstrated the crucial role of hormones in regulating head-splitting resistance.Bol028000,encoding a homologue of Arabidopsis Cytokinin Response Factor 3(CRF3),emerged as a promising candidate for head-splitting resistance and was subsequently validated through Sanger sequencing and quantitative RT-PCR(qRT-PCR).Subcellular localisation analysis revealed that Bol028000 was mainly expressed in the nucleus.Additionally,one kompetitive allele-specific PCR(KASP) marker from Bol028000 was developed and utilized to screen 42 inbred lines.These findings enhance the theoretical understanding of head-splitting resistance and provide valuable insights for the molecular breeding of head-splitting resistant cabbages.
基金supported by the Major Planning Project of Philosophy and Social Science of Guangdong Province(GD23ZD17)the Humanities and Social Sciences Program of the Ministry of Education(23YJA190006)+3 种基金the Ministry of Education(MOE)Major Project of Philosophy and Social Sciences Research(2025JZDZ024)the MOE Project of the Key Research Institute of Humanities and Social Sciences in Universities(22JJD190008)a grant from the Research Center for Brain Cognition and Human Development of Guangdong(2024B0303390003)the Psychological Services and Counseling Base for the Happy Guangzhou Project.
文摘Background:Exposure to environmental vulnerability poses significant threats to adolescent suicidal ideation,while individual resilience can mitigate these adverse effects with notable gender commonalities and differences.However,research examining how these factors co-configure at the individual level remains limited,particularly from a gender-specific perspective.Thus,the present study aims to adopt a person-centered analytic approach to identify gender-specific configurations of environmental vulnerability and individual resilience associated with suicidal ideation among Chinese adolescents.Methods:Data were collected from 2616 Chinese primary and secondary school students(aged 10–17;1223 girls).Participants completed validated scales measuring environmental vulnerability,individual resilience,and suicidal ideation.Latent profile analysis(LPA)was conducted separately by gender.Results:Gender differences were prominent:males exhibited higher resilience and lower suicidal ideation,while females reported higher environmental vulnerability and elevated levels of suicidal ideation.LPA identified three distinct profiles for males:Low Vulnerable–High Protective–Low Risk(LHL),Medium Vulnerable–Low Protective–Low Risk(MLL),and High Vulnerable–Low Protective–High Risk(HLH).Four profiles emerged for females:LHL,MLL,Medium Vulnerable–Low Protective–Medium Risk(MLM),and HLH.Crucially,within the HLH profile,males exhibited particularly deficient humor(η^(2)=0.19)and confidence(η^(2)=0.16),while females formed a distinct subgroup characterized by severe academic and family stressors(η^(2)=0.30–0.36).Conclusion:The study underscores developing gender-specific mental health interventions using a nuanced,person-centered approach that considers both environmental risk and individual resilience factors,which allows for targeted suicide prevention strategies addressing the unique needs of male and female adolescents.
