Human motion induced vibration has very low frequency,ranging from 2 Hz to 5 Hz.Traditional vibration isolators are not effective in low-frequency regions due to the trade-off between the low natural frequency and the...Human motion induced vibration has very low frequency,ranging from 2 Hz to 5 Hz.Traditional vibration isolators are not effective in low-frequency regions due to the trade-off between the low natural frequency and the high load capacity.In this paper,inspired by the human spine,we propose a novel bionic human spine inspired quasi-zero stiffness(QZS)vibration isolator which consists of a cascaded multi-stage negative stiffness structure.The force and stiffness characteristics are investigated first,the dynamic model is established by Newton’s second law,and the isolation performance is analyzed by the harmonic balance method(HBM).Numerical results show that the bionic isolator can obtain better low-frequency isolation performance by increasing the number of negative structure stages,and reducing the damping values and external force values can obtain better low-frequency isolation performance.In comparison with the linear structure and existing traditional QZS isolator,the bionic spine isolator has better vibration isolation performance in low-frequency regions.It paves the way for the design of bionic ultra-low-frequency isolators and shows potential in many engineering applications.展开更多
Phase change materials(PCMs)have attracted significant attention in thermal management due to their ability to store and release large amounts of heat during phase transitions.However,their widespread application is r...Phase change materials(PCMs)have attracted significant attention in thermal management due to their ability to store and release large amounts of heat during phase transitions.However,their widespread application is restricted by leakage issues.Encapsulating PCMs within polymeric microcapsules is a promising strategy to prevent leakage and increase heat transfer area with matrices.Moreover,photothermal PCM microcapsules are particularly desirable for solar energy storage.Herein,we fabricated photothermal PCM microcapsules with melamine-formaldehyde resin(MF)as shell using cellulose nanocrystal(CNC)and graphene oxide(GO)co-stabilized Pickering emulsion droplets as templates.CNC displays outstanding Pickering emulsifying ability and can facilitate the fixation of GO at the oil-water interface,resulting in a stable CNC/GO co-stabilized PCM Pickering emulsion.A polydopamine(PDA)layer was coated in-situ on the emulsion droplets via oxidization self-polymerization of dopamine.Meanwhile,GO was reduced to reduced GO(rGO)due to the reducing ability of PDA.The outmost MF shell of the PCM microcapsules was formed in-situ through the polymerization and crosslinking of MF prepolymer.The resulted PCM@CNC/rGO/PDA/MF microcapsules exhibit uniform sizes in the micrometer range,excellent leakage-proof performance,high phase change enthalpy(175.4 J g^(−1))and PCM encapsulation content(84.2%).Moreover,the presence of rGO and PDA endows PCM@CNC/rGO/PDA/MF microcapsules with outstanding photothermal conversion performance.The temperature of PCM@CNC/rGO/PDA/MF microcapsule slurries(15wt.%)can reach 73°C after light irradiation at 1 W cm^(−2).Therefore,photothermal PCM@CNC/rGO/PDA/MF microcapsules are promising for solar energy harvesting,thermal energy storage,and release in various applications,such as energy-efficient buildings and smart textiles.展开更多
Vibrating flip-flow screens(VFFS)with stretchable polyurethane sieve mats have been widely used in screening fine-grained materials in recent years.In this work,the discrete element method(DEM)is used to study the scr...Vibrating flip-flow screens(VFFS)with stretchable polyurethane sieve mats have been widely used in screening fine-grained materials in recent years.In this work,the discrete element method(DEM)is used to study the screening process in VFFS to explain particle flow and separation behavior at the particle scale.Unlike traditional vibrating screens,for VFFS,the amplitude response of each point on the elastic sieve mat is different everywhere.This study measures the kinematics of the elastic sieve mat under different conditions such as different stretched lengths and material loads.To establish the elastic sieve mat model in a DEM simulation,the continuous elastic sieve mat is discretized into multiple units,and the displacement signal of each unit tested is analyzed by Fourier series.The Fourier series analysis results of each unit are used as the setting parameters for motion.In this way,the movement of the elastic sieve mat is approximately simulated,and a DEM model of VFFS is produced.Through the simulation,the flow and separation of different-sized particles in VFFS are studied,and the reasonability of the simulation is verified by a pilot-scale screening experiment.The present study demonstrates the potential of the DEM method for the analysis of screening processes in VFFS.展开更多
SEL1L-mediated endoplasmic reticulum-associated degradation(ERAD)plays critical roles in controlling protein homeostasis by degrading misfolded or terminal unfolded proteins.However,it remains unclear how SEL1L regula...SEL1L-mediated endoplasmic reticulum-associated degradation(ERAD)plays critical roles in controlling protein homeostasis by degrading misfolded or terminal unfolded proteins.However,it remains unclear how SEL1L regulates peripheral T-cell survival and homeostasis.Herein,we found that SEL1L deficiency led to a greatly reduced frequency and number of mature T cells,which was further validated by adoptive transfer experiments or bone marrow chimera experiments,accompanied by the induction of multiple forms of cell death.Furthermore,SEL1L deficiency selectively disrupted naïve CD8+T-cell homeostasis,as indicated by the severe loss of the naïve T-cell subset but an increase in the memory T-cell subset.We also found that SEL1L deficiency fueled mTORC1/c-MYC activation and induced a metabolic shift,which was largely attributable to enhanced expression of the IL-15 receptorαandβchains.Mechanistically,single-cell transcriptomic profiling and biochemical analyses further revealed that Sel1l−/−CD8+T cells harbored excessive ER stress,particularly aberrant activation of the PERK-ATF4-CHOP-Bim pathway,which was alleviated by supplementing IL-7 or IL-15.Importantly,PERK inhibition greatly resolved the survival defects of Sel1l−/−CD8+T cells.In addition,IRE1αdeficiency decreased mTORC1 signaling in Sel1l−/−naïve CD8+T cells by downregulating the IL-15 receptorαchain.Altogether,these observations suggest that the ERAD adaptor molecule SEL1L acts as an important checkpoint for preserving the survival and homeostasis of peripheral T cells by regulating the PERK signaling cascade and IL-15 receptor-mediated mTORC1 axis.展开更多
基金supported by the National Natural Science Foundation of China(No.12072221)the Natural Science Foundation of Liaoning Province of China(No.2019-KF-01-09)。
文摘Human motion induced vibration has very low frequency,ranging from 2 Hz to 5 Hz.Traditional vibration isolators are not effective in low-frequency regions due to the trade-off between the low natural frequency and the high load capacity.In this paper,inspired by the human spine,we propose a novel bionic human spine inspired quasi-zero stiffness(QZS)vibration isolator which consists of a cascaded multi-stage negative stiffness structure.The force and stiffness characteristics are investigated first,the dynamic model is established by Newton’s second law,and the isolation performance is analyzed by the harmonic balance method(HBM).Numerical results show that the bionic isolator can obtain better low-frequency isolation performance by increasing the number of negative structure stages,and reducing the damping values and external force values can obtain better low-frequency isolation performance.In comparison with the linear structure and existing traditional QZS isolator,the bionic spine isolator has better vibration isolation performance in low-frequency regions.It paves the way for the design of bionic ultra-low-frequency isolators and shows potential in many engineering applications.
基金supported by the Youth Promotion of Guangdong Natural Science Foundation(2024A1515030005)Guangdong Province University Key Field Special Program(2023ZDZX3002)+9 种基金High-end Foreign Experts Recruitment Plan of China,State Key Laboratory of Pulp and Paper Engineering(202314)Key Laboratory of National Forestry and Grassland Administration on Highly-Efficient Utilization of Forestry Biomass Resources in Southwest China,Southwest Forestry University(2023KF11)Programs of Science and Technology Department of Yunnan Province(202301AT070217)Open Funding Project of the State Key Laboratory of Biocatalysis and Enzyme Engineering(SKLBEE2022006)National Natural Science Foundation of China(51973175,22107024,52103045)Guangdong Provincial Key Laboratory of Optical Information Materials and Technology(2023B1212060065)MOE International Laboratory for Optical Information Technologiesthe 111 ProjectScience and Technology Bureau of Huzhou(2022GG24)ScienceK Ltd.
文摘Phase change materials(PCMs)have attracted significant attention in thermal management due to their ability to store and release large amounts of heat during phase transitions.However,their widespread application is restricted by leakage issues.Encapsulating PCMs within polymeric microcapsules is a promising strategy to prevent leakage and increase heat transfer area with matrices.Moreover,photothermal PCM microcapsules are particularly desirable for solar energy storage.Herein,we fabricated photothermal PCM microcapsules with melamine-formaldehyde resin(MF)as shell using cellulose nanocrystal(CNC)and graphene oxide(GO)co-stabilized Pickering emulsion droplets as templates.CNC displays outstanding Pickering emulsifying ability and can facilitate the fixation of GO at the oil-water interface,resulting in a stable CNC/GO co-stabilized PCM Pickering emulsion.A polydopamine(PDA)layer was coated in-situ on the emulsion droplets via oxidization self-polymerization of dopamine.Meanwhile,GO was reduced to reduced GO(rGO)due to the reducing ability of PDA.The outmost MF shell of the PCM microcapsules was formed in-situ through the polymerization and crosslinking of MF prepolymer.The resulted PCM@CNC/rGO/PDA/MF microcapsules exhibit uniform sizes in the micrometer range,excellent leakage-proof performance,high phase change enthalpy(175.4 J g^(−1))and PCM encapsulation content(84.2%).Moreover,the presence of rGO and PDA endows PCM@CNC/rGO/PDA/MF microcapsules with outstanding photothermal conversion performance.The temperature of PCM@CNC/rGO/PDA/MF microcapsule slurries(15wt.%)can reach 73°C after light irradiation at 1 W cm^(−2).Therefore,photothermal PCM@CNC/rGO/PDA/MF microcapsules are promising for solar energy harvesting,thermal energy storage,and release in various applications,such as energy-efficient buildings and smart textiles.
基金supported by the Fundamental Research Funds for the Central Universities (grant No.2021YJSHH32)Anhui Province Major Science and Technology Achievements Engineering Research and Development Special Project (grant No.202103c08020007).
文摘Vibrating flip-flow screens(VFFS)with stretchable polyurethane sieve mats have been widely used in screening fine-grained materials in recent years.In this work,the discrete element method(DEM)is used to study the screening process in VFFS to explain particle flow and separation behavior at the particle scale.Unlike traditional vibrating screens,for VFFS,the amplitude response of each point on the elastic sieve mat is different everywhere.This study measures the kinematics of the elastic sieve mat under different conditions such as different stretched lengths and material loads.To establish the elastic sieve mat model in a DEM simulation,the continuous elastic sieve mat is discretized into multiple units,and the displacement signal of each unit tested is analyzed by Fourier series.The Fourier series analysis results of each unit are used as the setting parameters for motion.In this way,the movement of the elastic sieve mat is approximately simulated,and a DEM model of VFFS is produced.Through the simulation,the flow and separation of different-sized particles in VFFS are studied,and the reasonability of the simulation is verified by a pilot-scale screening experiment.The present study demonstrates the potential of the DEM method for the analysis of screening processes in VFFS.
基金supported by the National Key R&D Program of China(2022YFA0807300)the National Natural Science Foundation of China(82271775 and 81971466)+1 种基金the Natural Science Foundation Outstanding Youth Fund of Jiangsu Province(BK20220049)and the CAMS Innovation Fund for Medical Sciences(CIFMS 2021-I2M-1-061,2021-I2M-1-047 and 2022-I2M-2-004).BZ was in part supported by the Innovation Capability Support Program of Shaanxi 2021TD-38.JZ was in part supported by a Translational Research Grant of NCRCH(2020ZKZC04)and the National Natural Science Foundation of China(82071765)supported by the Natural Science Foundation of China(NSFC 31900645).We thank Prof.Yonghong Wan from McMaster University,Canada,for his critical reading of the manuscript and helpful discussions.
文摘SEL1L-mediated endoplasmic reticulum-associated degradation(ERAD)plays critical roles in controlling protein homeostasis by degrading misfolded or terminal unfolded proteins.However,it remains unclear how SEL1L regulates peripheral T-cell survival and homeostasis.Herein,we found that SEL1L deficiency led to a greatly reduced frequency and number of mature T cells,which was further validated by adoptive transfer experiments or bone marrow chimera experiments,accompanied by the induction of multiple forms of cell death.Furthermore,SEL1L deficiency selectively disrupted naïve CD8+T-cell homeostasis,as indicated by the severe loss of the naïve T-cell subset but an increase in the memory T-cell subset.We also found that SEL1L deficiency fueled mTORC1/c-MYC activation and induced a metabolic shift,which was largely attributable to enhanced expression of the IL-15 receptorαandβchains.Mechanistically,single-cell transcriptomic profiling and biochemical analyses further revealed that Sel1l−/−CD8+T cells harbored excessive ER stress,particularly aberrant activation of the PERK-ATF4-CHOP-Bim pathway,which was alleviated by supplementing IL-7 or IL-15.Importantly,PERK inhibition greatly resolved the survival defects of Sel1l−/−CD8+T cells.In addition,IRE1αdeficiency decreased mTORC1 signaling in Sel1l−/−naïve CD8+T cells by downregulating the IL-15 receptorαchain.Altogether,these observations suggest that the ERAD adaptor molecule SEL1L acts as an important checkpoint for preserving the survival and homeostasis of peripheral T cells by regulating the PERK signaling cascade and IL-15 receptor-mediated mTORC1 axis.
