The clinical application of Chuanminshen violaceum polysaccharides(CVP),a natural immunomodulator with intrinsic antioxidant activity,is constrained by rapid systemic clearance,limited tissue specificity,and short-liv...The clinical application of Chuanminshen violaceum polysaccharides(CVP),a natural immunomodulator with intrinsic antioxidant activity,is constrained by rapid systemic clearance,limited tissue specificity,and short-lived bioactivity.To address these limitations,a multifunctional biomimetic nanoplatform incorporating erythrocyte membrane camouflage,mannose-mediated active targeting,and squalene-stabilized Pickering emulsion technology was developed.CVP-loaded poly(lactic-co-glycolic acid)(PLGA)nanoparticles(CVPP)were fabricated via solvent evaporation,coated with erythrocyte membranes,and subsequently functionalized with mannose to obtain CVPP@M-M.This dual modification enabled selective recognition by macrophage and dendritic cell(DC)mannose receptors,while the erythrocyte membrane imparted prolonged systemic circulation.Subsequent emulsification for the first time with squalene yielded CVPP@M-M-PPAS,a Pickering emulsion designed for enhanced lymph node delivery.In vitro,CVPP@M-M-PPAS significantly promoted macrophage activation,as evidenced by elevated CD80+/CD86+expression,compared with free CVP.In vivo,intramuscular co-administration with ovalbumin(OVA)antigen induced pronounced DC maturation and T cell polarization in the spleen.This formulation also elicited robust and sustained production of antigen-specific IgG,accompanied by increased upregulation of pro-inflammatory cytokines interleukin-6(IL-6)and interferon-γ(IFN-γ).In vivo imaging demonstrated prolonged lymph node retention(>336 h)with a near-linear fluorescence decay profile,confirming controlled release kinetics.By integrating stealth properties,receptor-specific targeting,and emulsion-enabled lymphatic trafficking,this nanoplatform effectively circumvents the pharmacokinetic and biodistributional barriers of plant-derived polysaccharides,enabling durable humoral and cellular immune responses.This strategy offers a generalizable framework for translating natural immunomodulators into clinically viable nanotherapeutics.展开更多
In this paper,dependence of magnetic properties on microstructure and composition of Ce-Fe-B sintered magnets with Cu-doped Ce-rich alloy addition was investigated.It shows that the maximum energy product(BH)(max)and ...In this paper,dependence of magnetic properties on microstructure and composition of Ce-Fe-B sintered magnets with Cu-doped Ce-rich alloy addition was investigated.It shows that the maximum energy product(BH)(max)and coercivity H(cj)of Ce-Fe-B sintered magnet are improved from 6.76 to 9.13 MGOe by 35.1%,and from 1.44 to 1.67 kOe by 16.0%,respectively,via adding 5 wt%liquid phase alloy of Ce(35.58)Fe(57.47)Cu6 B(0.95)(at%).Compared with the magnet without Cerich alloy addition,the volume fraction of the grain-boundary phase with low melting point increases in the magnet with Ce-rich alloy additio n,which is be ne ficial to imp roving the microstructure and promoting the coercivity enhancement of the magnet.In the Ce-Fe-B magnet with Ce-rich alloy addition,Cu and Ce enrich in the grain boundaries of the magnet after annealing,therefore the as-annealed magnet has a higher coercivity than the as-sintered magnet.A distinct Fe-rich layer with the average thickness of 60 nm is found in the grain boundaries in the magnet without Ce-rich alloy addition,but it seems that Fe-rich phase disappears in the magnet with Ce-rich alloy addition.The present work suggests that the further improvement of coercivity in the Ce-Fe-B sintered magnets is expectable by designing the composition and structure of added liquid phase alloys.展开更多
Understandings of the effect of hot deformation parameters close to the practical production line on grain refinement are crucial for enhancing both the strength and toughness of future rail steels.In this work,the au...Understandings of the effect of hot deformation parameters close to the practical production line on grain refinement are crucial for enhancing both the strength and toughness of future rail steels.In this work,the austenite dynamic recrystallization(DRX)behaviors of a eutectoid pearlite rail steel were studied using a thermo-mechanical simulator with hot deformation parameters frequently employed in rail production lines.The single-pass hot deformation results reveal that the prior austenite grain sizes(PAGSs)for samples with different deformation reductions decrease initially with an increase in deformation temperature.However,once the deformation temperature is beyond a certain threshold,the PAGSs start to increase.It can be attributed to the rise in DRX volume fraction and the increase of DRX grain with deformation temperature,respectively.Three-pass hot deformation results show that the accumulated strain generated in the first and second deformation passes can increase the extent of DRX.In the case of complete DRX,PAGS is predominantly determined by the deformation temperature of the final pass.It suggests a strategic approach during industrial production where part of the deformation reduction in low temperature range can be shifted to the medium temperature range to release rolling mill loads.展开更多
Design and manufacturing play pivotal roles in hydraulic-driven robotic development.However,previous studies have emphasized mainly results and performance,often overlooking the specifics of the design and manufacturi...Design and manufacturing play pivotal roles in hydraulic-driven robotic development.However,previous studies have emphasized mainly results and performance,often overlooking the specifics of the design and manufacturing process.This paper introduces a novel approach known as light weight design and integrated manufacturing(LD&IM)for hydraulic wheel-legged robots.The LD&IM method leverages topology optimization and generative design techniques to achieve a substantial 45%weight reduction,enhancing the robot’s dynamic motion capabilities.This innovative design method not only streamlines the design process but also upholds the crucial attributes of light weight construction and high strength essential for hydraulic wheel-legged robots.Furthermore,the integrated manufacturing method,incorporating selective laser melting(SLM)and high-precision subtractive manufacturing(SM)processes,expedites the fabrication of high-quality components.Using the LD&IM approach,a hydraulic-driven single wheel-legged robot,denoted as WLR-IV,has been successfully developed.This robot boasts low mass and inertia,high strength,and a simplified component structure.To assess its dynamic jumping capabilities,the control loop integrates a linear quadratic regulator(LQR)and zero dynamic-based controller,while trajectory planning uses the spring-loaded inverted pendulum(SLIP)model.Experimental jumping results confirm the WLR-IV single-legged robot’s exceptional dynamic performance,validating both the effectiveness of the LD&IM method and the rationale behind the control strategy.展开更多
Sintered Nd-Ce-Fe-B magnets were grain boundary diffused(GBDed) with Pr_(x)Tb_(80-x)Al_(10)Ga_(10)(at%)(x=0,20,40,60,80) alloys.The effect of Pr/Tb content in diffusion source on magnetic properties,microstructure and...Sintered Nd-Ce-Fe-B magnets were grain boundary diffused(GBDed) with Pr_(x)Tb_(80-x)Al_(10)Ga_(10)(at%)(x=0,20,40,60,80) alloys.The effect of Pr/Tb content in diffusion source on magnetic properties,microstructure and elements distribution of GBDed magnets was investigated.When Pr is used to substitute for 75% Tb in diffusion source,Tb consumption per unit coercivity improvement of GBDed magnet reduces by 77%,compared with the Tb_(80)Al_(10)Ga_(10) diffused magnet.Tb element diffuses into magnets and then forms Tb-rich shell with high magneto-crystalline anisotropy field surrounding main phase grains,resulting in substantial coercivity improvement.Pr with low melting point diffuses deeply along liquid grain boundary phase during GBD process.It can eliminate some sharp defects of main phase grains and make grain boundaries smooth,which provides diffusion channels for further diffusion of Tb element.Therefore,there are more diffusion channels for Tb and less Tb enriched at surface region,making Tb diffuse more deeply and improving Tb utilization efficiency.This method significantly improves the coercivity,and realizes the green,efficient and high-quality utilization of heavy rare earth(HRE)elements.展开更多
The continuous pursuit of extremely lightweight and multi-functional integrated designs in modern industries requires that structural materials are not limited to ensuring the structural load-bearing function of light...The continuous pursuit of extremely lightweight and multi-functional integrated designs in modern industries requires that structural materials are not limited to ensuring the structural load-bearing function of lightweight designs;rather,they must have high mechanical properties and high damping capabilities.Self-healing materials are becoming popular because of their attractive repairability and reprocessability.Dynamic reversible bonds,which are included in self-healing polymer networks,have been extensively studied with respect to different chemical mechanisms.Nevertheless,the ability to reach high stiffness and high damping performance is crucial.In this review,different types of self-healing materials are introduced,and their complex and contradictory relationships with stiffness,damping,and self-healing properties are explained.This review combines intrinsic damping sources and extrinsic deformation driving modes as a holistic concept of material–structure–performance integrated design methodology to address the extensive challenges of increasing specific damping performance.Specifically,the sources of damping at the nanolevel and the deformation-driving modes at different levels of structural hierarchy are explained in depth to reveal the cross-scale coordination between intrinsic damping sources and extrinsic deformation-driven modes originating from extremely different length scales in the microstructural architecture of a material.The material–structure–performance integrated design methodology is expected to become a key strategy for the sustainable development of breakthrough and transformative damping composite structures for aerospace,terrestrial,and marine transportation.展开更多
The robot used for disaster rescue or field exploration requires the ability of fast moving on flat road and adaptability on complex terrain.The hybrid wheel-legged robot(WLR-3P,prototype of the third-generation hydra...The robot used for disaster rescue or field exploration requires the ability of fast moving on flat road and adaptability on complex terrain.The hybrid wheel-legged robot(WLR-3P,prototype of the third-generation hydraulic wheel-legged robot)has the characteristics of fast and efficient mobility on flat surfaces and high environmental adaptability on rough terrains.In this paper,3 design requirements are proposed to improve the mobility and environmental adaptability of the robot.To meet these 3 requirements,2 design principles for each requirement are put forward.First,for light weight and low inertia with high stiffness,3-dimensional printing technology and lightweight material are adopted.Second,the integrated hydraulically driven unit is used for high power density and fast response actuation.Third,the microhydraulic power unit achieves power autonomy,adopting the hoseless design to strengthen the reliability of the hydraulic system.What is more,the control system including hierarchical distributed electrical system and control strategy is presented.The mobility and adaptability of WLR-3P are demonstrated with a series of experiments.Finally,the robot can achieve a speed of 13.6 km/h and a jumping height of 0.2 m.展开更多
基金supported by the Natural Science Foundation of Sichuan(No.2024NSFJQ0005)in part by the Scientific and Technological Innovation Team for Qinghai-Tibetan Plateau Research in Southwest Minzu University(No.2024CXTD15).
文摘The clinical application of Chuanminshen violaceum polysaccharides(CVP),a natural immunomodulator with intrinsic antioxidant activity,is constrained by rapid systemic clearance,limited tissue specificity,and short-lived bioactivity.To address these limitations,a multifunctional biomimetic nanoplatform incorporating erythrocyte membrane camouflage,mannose-mediated active targeting,and squalene-stabilized Pickering emulsion technology was developed.CVP-loaded poly(lactic-co-glycolic acid)(PLGA)nanoparticles(CVPP)were fabricated via solvent evaporation,coated with erythrocyte membranes,and subsequently functionalized with mannose to obtain CVPP@M-M.This dual modification enabled selective recognition by macrophage and dendritic cell(DC)mannose receptors,while the erythrocyte membrane imparted prolonged systemic circulation.Subsequent emulsification for the first time with squalene yielded CVPP@M-M-PPAS,a Pickering emulsion designed for enhanced lymph node delivery.In vitro,CVPP@M-M-PPAS significantly promoted macrophage activation,as evidenced by elevated CD80+/CD86+expression,compared with free CVP.In vivo,intramuscular co-administration with ovalbumin(OVA)antigen induced pronounced DC maturation and T cell polarization in the spleen.This formulation also elicited robust and sustained production of antigen-specific IgG,accompanied by increased upregulation of pro-inflammatory cytokines interleukin-6(IL-6)and interferon-γ(IFN-γ).In vivo imaging demonstrated prolonged lymph node retention(>336 h)with a near-linear fluorescence decay profile,confirming controlled release kinetics.By integrating stealth properties,receptor-specific targeting,and emulsion-enabled lymphatic trafficking,this nanoplatform effectively circumvents the pharmacokinetic and biodistributional barriers of plant-derived polysaccharides,enabling durable humoral and cellular immune responses.This strategy offers a generalizable framework for translating natural immunomodulators into clinically viable nanotherapeutics.
基金Project supported by the National Natural Science Foundation of China(51590882)the Plan of National Key Research and Development of China(2016YFB0700903)
文摘In this paper,dependence of magnetic properties on microstructure and composition of Ce-Fe-B sintered magnets with Cu-doped Ce-rich alloy addition was investigated.It shows that the maximum energy product(BH)(max)and coercivity H(cj)of Ce-Fe-B sintered magnet are improved from 6.76 to 9.13 MGOe by 35.1%,and from 1.44 to 1.67 kOe by 16.0%,respectively,via adding 5 wt%liquid phase alloy of Ce(35.58)Fe(57.47)Cu6 B(0.95)(at%).Compared with the magnet without Cerich alloy addition,the volume fraction of the grain-boundary phase with low melting point increases in the magnet with Ce-rich alloy additio n,which is be ne ficial to imp roving the microstructure and promoting the coercivity enhancement of the magnet.In the Ce-Fe-B magnet with Ce-rich alloy addition,Cu and Ce enrich in the grain boundaries of the magnet after annealing,therefore the as-annealed magnet has a higher coercivity than the as-sintered magnet.A distinct Fe-rich layer with the average thickness of 60 nm is found in the grain boundaries in the magnet without Ce-rich alloy addition,but it seems that Fe-rich phase disappears in the magnet with Ce-rich alloy addition.The present work suggests that the further improvement of coercivity in the Ce-Fe-B sintered magnets is expectable by designing the composition and structure of added liquid phase alloys.
基金financially supported by the National Natural Science Foundation of China(Nos.52293395 and 52293393)the Xiongan Science and Technology Innovation Talent Project of MOST,China(No.2022XACX0500)。
文摘Understandings of the effect of hot deformation parameters close to the practical production line on grain refinement are crucial for enhancing both the strength and toughness of future rail steels.In this work,the austenite dynamic recrystallization(DRX)behaviors of a eutectoid pearlite rail steel were studied using a thermo-mechanical simulator with hot deformation parameters frequently employed in rail production lines.The single-pass hot deformation results reveal that the prior austenite grain sizes(PAGSs)for samples with different deformation reductions decrease initially with an increase in deformation temperature.However,once the deformation temperature is beyond a certain threshold,the PAGSs start to increase.It can be attributed to the rise in DRX volume fraction and the increase of DRX grain with deformation temperature,respectively.Three-pass hot deformation results show that the accumulated strain generated in the first and second deformation passes can increase the extent of DRX.In the case of complete DRX,PAGS is predominantly determined by the deformation temperature of the final pass.It suggests a strategic approach during industrial production where part of the deformation reduction in low temperature range can be shifted to the medium temperature range to release rolling mill loads.
基金Heilongjiang Provincial Youth Science and Technology Talent Support Project(No.2023QNTJ008)Self-Planned Task of State Key Laboratory of Robotics and System from Harbin Institute of Technology(HIT)(No.SKLRS 202301A03)Open Foundation of the State Key Laboratory of Fluid Power and Mechatronic Systems(No.GZKF-202203),China.
文摘Design and manufacturing play pivotal roles in hydraulic-driven robotic development.However,previous studies have emphasized mainly results and performance,often overlooking the specifics of the design and manufacturing process.This paper introduces a novel approach known as light weight design and integrated manufacturing(LD&IM)for hydraulic wheel-legged robots.The LD&IM method leverages topology optimization and generative design techniques to achieve a substantial 45%weight reduction,enhancing the robot’s dynamic motion capabilities.This innovative design method not only streamlines the design process but also upholds the crucial attributes of light weight construction and high strength essential for hydraulic wheel-legged robots.Furthermore,the integrated manufacturing method,incorporating selective laser melting(SLM)and high-precision subtractive manufacturing(SM)processes,expedites the fabrication of high-quality components.Using the LD&IM approach,a hydraulic-driven single wheel-legged robot,denoted as WLR-IV,has been successfully developed.This robot boasts low mass and inertia,high strength,and a simplified component structure.To assess its dynamic jumping capabilities,the control loop integrates a linear quadratic regulator(LQR)and zero dynamic-based controller,while trajectory planning uses the spring-loaded inverted pendulum(SLIP)model.Experimental jumping results confirm the WLR-IV single-legged robot’s exceptional dynamic performance,validating both the effectiveness of the LD&IM method and the rationale behind the control strategy.
基金Project supported by the National Key Research and Development Program of China (2022YFB3503303)。
文摘Sintered Nd-Ce-Fe-B magnets were grain boundary diffused(GBDed) with Pr_(x)Tb_(80-x)Al_(10)Ga_(10)(at%)(x=0,20,40,60,80) alloys.The effect of Pr/Tb content in diffusion source on magnetic properties,microstructure and elements distribution of GBDed magnets was investigated.When Pr is used to substitute for 75% Tb in diffusion source,Tb consumption per unit coercivity improvement of GBDed magnet reduces by 77%,compared with the Tb_(80)Al_(10)Ga_(10) diffused magnet.Tb element diffuses into magnets and then forms Tb-rich shell with high magneto-crystalline anisotropy field surrounding main phase grains,resulting in substantial coercivity improvement.Pr with low melting point diffuses deeply along liquid grain boundary phase during GBD process.It can eliminate some sharp defects of main phase grains and make grain boundaries smooth,which provides diffusion channels for further diffusion of Tb element.Therefore,there are more diffusion channels for Tb and less Tb enriched at surface region,making Tb diffuse more deeply and improving Tb utilization efficiency.This method significantly improves the coercivity,and realizes the green,efficient and high-quality utilization of heavy rare earth(HRE)elements.
基金supported by the National Natural Science Foundation of China(Grant No.52175095)the Young Top-notch Talent Cultivation Program of Hubei Province of China.
文摘The continuous pursuit of extremely lightweight and multi-functional integrated designs in modern industries requires that structural materials are not limited to ensuring the structural load-bearing function of lightweight designs;rather,they must have high mechanical properties and high damping capabilities.Self-healing materials are becoming popular because of their attractive repairability and reprocessability.Dynamic reversible bonds,which are included in self-healing polymer networks,have been extensively studied with respect to different chemical mechanisms.Nevertheless,the ability to reach high stiffness and high damping performance is crucial.In this review,different types of self-healing materials are introduced,and their complex and contradictory relationships with stiffness,damping,and self-healing properties are explained.This review combines intrinsic damping sources and extrinsic deformation driving modes as a holistic concept of material–structure–performance integrated design methodology to address the extensive challenges of increasing specific damping performance.Specifically,the sources of damping at the nanolevel and the deformation-driving modes at different levels of structural hierarchy are explained in depth to reveal the cross-scale coordination between intrinsic damping sources and extrinsic deformation-driven modes originating from extremely different length scales in the microstructural architecture of a material.The material–structure–performance integrated design methodology is expected to become a key strategy for the sustainable development of breakthrough and transformative damping composite structures for aerospace,terrestrial,and marine transportation.
基金supported by the Innovative Research Groups of the National Natural Science Foundation of China(51521003)the Natural Science Foundation of Heilongjiang Province of China(YQ2021F011)+1 种基金Key Research Project of Zhejiang Lab(no.115002-AC2101)funded by Open Foundation of the State Key Laboratory of Fluid Power and Mechatronic Systems。
文摘The robot used for disaster rescue or field exploration requires the ability of fast moving on flat road and adaptability on complex terrain.The hybrid wheel-legged robot(WLR-3P,prototype of the third-generation hydraulic wheel-legged robot)has the characteristics of fast and efficient mobility on flat surfaces and high environmental adaptability on rough terrains.In this paper,3 design requirements are proposed to improve the mobility and environmental adaptability of the robot.To meet these 3 requirements,2 design principles for each requirement are put forward.First,for light weight and low inertia with high stiffness,3-dimensional printing technology and lightweight material are adopted.Second,the integrated hydraulically driven unit is used for high power density and fast response actuation.Third,the microhydraulic power unit achieves power autonomy,adopting the hoseless design to strengthen the reliability of the hydraulic system.What is more,the control system including hierarchical distributed electrical system and control strategy is presented.The mobility and adaptability of WLR-3P are demonstrated with a series of experiments.Finally,the robot can achieve a speed of 13.6 km/h and a jumping height of 0.2 m.
