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Multi-layer quasi-zero-stiffness meta-structure for high-efficiency vibration isolation at low frequency

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Applied Mathematics and Mechanics(English Edition) 2024年第7期45卷 1189-1208页

作者： Jiahao zhou Jiaxi zhou Hongbin PAN Kai WANG Changqi CAI Guilin WEN College of Mechanical and Vehicle Engineering Hunan University State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body The Ministry of Science and Technology School of Mechanical Engineering Zhejiang Sci-Tech University School of Mechanical Engineering Yanshan University

An easily stackable multi-layer quasi-zero-stiffness(ML-QZS) meta-structure is proposed to achieve highly efficient vibration isolation performance at low ***, the distributed shape optimization method is used to design the unit cel, i.e., the single-layer QZS(SL-QZS) meta-structure. Second, the stiffness feature of the unit cell is investigated and verified through static experiments. Third, the unit cells are stacked one by one along the direction of vibration isolation, and thus the ML-QZS meta-structure is constructed. Fourth, the dynamic modeling of the ML-QZS vibration isolation metastructure is conducted, and the dynamic responses are obtained from the equations of motion, and verified by finite element(FE) simulations. Finally, a prototype of the ML-QZS vibration isolation meta-structure is fabricated by additive manufacturing, and the vibration isolation performance is evaluated experimentally. The results show that the vibration isolation performance substantially enhances when the number of unit cells increases. More importantly, the ML-QZS meta-structure can be easily extended in the direction of vibration isolation when the unit cells are properly stacked. Hence, the ML-FQZS vibration isolation meta-structure should be a fascinating solution for highly efficient vibration isolation performance at low frequency.

关键词： quasi-zero stiffness (QZS) meta-structure high efficiency low frequency vibration isolation O328 34C15 74P10

Southern Hemisphere Volcanism Triggered Multi-year La Niñas during the Last Millennium

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Advances in Atmospheric Sciences 2024年第4期41卷 587-592页

作者： Shangrong zhou Fei LIU School of Atmospheric Sciences Sun Yat-Sen University Key Laboratory of Tropical Atmosphere-Ocean System Ministry of Educationand Southern Marine Science and Engineering Guangdong LaboratoryZhuhai 519082China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD) Nanjing University of Information Science and TechnologyNanjing 210044China

To explain the recent three-year La Niña event from 2020 to 2022,which has caused catastrophic weather events worldwide,Fasullo et al.(2023)demonstrated that the increase in biomass aerosol resulting from the 2019-20 Australian wildfire season could have triggered this multi-year La Niñ***,we present compelling evidence from paleo-proxies,utilizing a substantial sample size of 26 volcanic eruptions in the Southern Hemisphere(SH),to support the hypothesis that ocean cooling in the SH can lead to a multi-year La Niña *** research highlights the importance of focusing on the Southern Ocean,as current climate models struggle to accurately simulate the Pacific response driven by the Southern Ocean.

关键词： volcanic eruptions multi-year La Niñas Australian wildfire southern ocean cooling

Perturbation of autophagy pathways in murine alveolar macrophage by 2D TMDCs is chalcogen-dependent

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Journal of Environmental Sciences 2024年第1期135卷 97-107页

作者： Xiaofei zhou Weitao Jin Rui Zhang Xuan Mao Jianbo Jia Hongyu zhou College of Science&Technology Hebei Agricultural UniversityHuanghua 061100China Institute of Environmental Research at Greater Bay Area Key Laboratory for Water Quality and Conservation of the Pearl River DeltaMinistry of EducationGuangzhou UniversityGuangzhou 510006China

Increasing risks of incidental and occupational exposures to two-dimensional transition metal dichalcogenides(2D TMDCs)due to their broad application in various areas raised their public health *** the composition-dependent cytotoxicity of 2D TMDCs has been well-recognized,how the outer chalcogenide atoms and inner transition metal atoms differentially contribute to their perturbation on cell homeostasis at non-lethal doses remains to be *** the present work,we compared the autophagy induction and related mechanisms in response to WS_(2),NbS_(2),WSe_(2)and Nb Se_(2)nanosheets exposures in MH-S murine alveolar *** these 2D TMDCs had comparable physicochemical properties,overall cytotoxicity and capability in triggering autophagy in MH-S cells,but showed outer chalcogen-dependent subcellular localization and activation of autophagy ***,WS_(2)and NbS_(2)nanosheets adhered on the cell surface and internalized in the lysosomes,and triggered m TOR-dependent activation of ***,WSe_(2)and Nb Se_(2)nanosheets had extensive distribution in cytoplasm of MH-S cells and induced autophagy in an m TOR-independent ***,the 2D TMDCs-induced perturbation on autophagy aggravated the cytotoxicity of respirable benzo[a]*** findings provide a deeper insight into the potential health risk of environmental 2D TMDCs from the perspective of homeostasis perturbation.

关键词： Chalcogen group Autophagy pathway Cell function Endosomal escape Inhalation toxicity

Natural polysaccharide-based smart CXCR4-targeted nano-system for magnified liver fibrosis therapy

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Chinese Chemical Letters 2024年第2期35卷 341-346页

作者： Liqiong Sun Xinping Luo Chenxi zhou Zhanwei zhou Minjie Sun College of Horticulture Nanjing Agricultural UniversityNanjing 210095China NMPA Key Laboratory for Research and Evaluation of Pharmaceutical Preparations and Excipients State Key Laboratory of Natural MedicinesDepartment of PharmaceuticsChina Pharmaceutical UniversityNanjing 210009China

Activated hepatic stellate cells(aHSCs),the main source of extracellular matrix deposition,are key targets in liver ***,no effective drug specific to aHSCs has been clinically applied due to poor drug delivery ***,we designed a CXC chemokine receptor 4(CXCR4)-targeted reactive oxygen species(ROS)-responsive platform AMD-Dex-ROS-responsive-sorafenib(ARS)based on natural polysaccharide and thioctic acid frame,which can deliver anti-fibrosis drug represented by sorafenib specifically to aHSCs on account of CXCR4 over-expression on aHSCs,and smartly disassemble via ROS-responsive thioketal rupture relying on high intracellular ROS in HSCs,realized on-demand drug release and effective liver fibrosis ***,in this platform,the CXCR4 antagonist AMD3100 not only enhanced aHSCs targeting efficiency of sorafenib but also effectively magnified the aHSCs elimination of sorafenib by blocking stroma cell derived factor-1(SDF-1)/CXCR4-induced aHSCs protection,resulting in synergistic anti-fibrosis *** platform provided a new approach for drug delivery system design and liver fibrosis treatment.

关键词： Nanoparticle CXCR4 antagonism ROS-responsive Hepatic stellate cells Liver fibrosis

Intrinsic correlation between the generalized phase equilibrium condition and mechanical behaviors in hydrate-bearing sediments

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第7期16卷 2822-2832页

作者： Jiazuo zhou Changfu Wei Rongtao Yan Yuan zhou Yi Dong Hubei Key Laboratory of Marine Geological Resources College of Marine Science and TechnologyChina University of GeosciencesWuhanChina State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhanChina Guangxi Key Laboratory of New Energy and Building Energy Saving College of Civil Engineering and ArchitectureGuilin University of TechnologyGuilinChina

The phase equilibrium and mechanical behaviors of natural gas hydrate-bearing sediment are essential for gas recovery from hydrate *** heating closed systems,the temperature-pressure path of hydrate-bearing sediment deviates from that of pure bulk hydrate,reflecting the porous media effect in phase equilibrium.A generalized phase equilibrium equation was established for hydrate-bearing sediments,which indicates that both capillary and osmotic pressures cause the phase equilibrium curve to shift leftward on the temperature-pressure *** contrast to bulk hydrate,hydrate-bearing sediment always contains a certain amount of unhydrated water,which keeps phase equilibrium with the hydrate within the hydrate stability *** changes in temperature and pressure,a portion of pore hydrate and unhydrated water may transform into each other,affecting the shear strength of hydrate-bearing sediment.A shear strength model is proposed to consider not only hydrate saturation but also the change in temperature and pressure of hydrate-bearing *** model is validated by experimental data with various hydrate saturation,temperature and pressure *** deformation induced by partial dissociation was studied through depressurization tests under constant effective *** reduction in gas pressure within the hydrate stability field indeed caused sediment *** dissociation-induced deformation can be reasonably estimated as the difference in volume between hydrate-bearing and hydrate-free sediments from the compression curves.

关键词： Hydrate-bearing sediment Generalized phase equilibrium Unhydrated water Partial dissociation Mechanical behavior

Combined proteomic and metabolomic studies on the liver of Amur sturgeon Acipenser schrenckii under titanium dioxide nanoparticle exposure

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Journal of Oceanology and Limnology 2024年第3期42卷 1001-1015页

作者： zhou zhou Ting LIU Jie KONG Zhenxing ZHAO Junquan ZHU Key Laboratory of Aquacultural Biotechnology Ministry of Educationand Key Laboratory of Marine Biotechnology of Zhejiang ProvinceCollege of Marine SciencesNingbo UniversityNingbo 315000China Guizhou Fisheries Research Institute Guizhou Academy of Agriculture SciencesGuiyang 550000China

Nanomaterials,particularly titanium dioxide nanoparticles(TiO_(2)-NPs),are extensively utilized across various ***,their environmental release has raised concerns regarding their potential ecological and environmental *** reproductive toxicity of TiO_(2)-NPs in fish species has attracted considerable attention,yet conflicting research outcomes have been *** investigated the effects of TiO_(2)-NPs exposure on the liver of juvenile Amur sturgeon Acipenser schrenckii using label-free proteomic and untargeted metabolomic *** experiment included a control group and three groups exposed to different concentrations of TiO_(2)-NPs(low,TL;medium,TM;high,TH).Compared to the control group,9,19,and 25 proteins and 35,73,and 158 metabolites were differentially expressed in the TH,TM,and TL TiO_(2)-NP-exposed groups,*** differentially expressed genes(DEGs)were enriched in the Kyoto Encyclopedia for Genes and Genomes(KEGG)pathways related to glycolysis and ***,among the 126 correlated proteins,the most enriched pathways were associated with endocytosis and protein processing in the endoplasmic ***,syringic acid was significantly downregulated across all three TiO_(2)-NP-exposed *** obtain a comprehensive overview of the TiO_(2)-NP-induced expression changes,a co-regulated network of proteins and metabolites associated with TiO_(2)-NPs exposure was *** to TiO_(2)-NPs led to enrichment and alteration of pathways related to immune responses,including endocytosis,protein processing in the endoplasmic reticulum,and peroxisome proliferator-activated receptor(PPAR)*** conclusion,our findings indicate that exposure to TiO_(2)-NPs might disrupt glucose metabolism and induce immune responses,thus contributing to our understanding of the environmental impacts of nanomaterials and highlighting the need for further research and development of potential mitigation strategies.

关键词： TiO_(2)-nanoparticle exposure proteomics metabolomics glucose metabolism immune response

Intelligent feedforward gust alleviation based on neural network

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Chinese Journal of Aeronautics 2024年第3期37卷 116-132页

作者： Yitao zhou Zhigang WU Chao YANG School of Aeronautic Science and Engineering Beihang UniversityBeijing 100191China

This paper proposes a neural network-based intelligent feedforward gust alleviation framework,which includes a neural network identification model and a neural network controller.A neural network training dataset is formed by collecting flight data and the gust data encountered during the aircraft flight.A neural network identification model is first trained to accurately predict the aircraft’s ***,based on the output of the identification model and the collected flight data,the parameters of the time-delay neural network controller are obtained through a learning *** simulation results show that the designed intelligent controller has good gust alleviation effects for both continuous turbulence excitation and discrete gust *** example,when the aircraft is 40000 kg and the flight speed is 0.81Ma,the controller achieves a 67.82%reduction in wingtip acceleration and a 35.90%reduction in center of mass acceleration under continuous turbulence *** considering the measurement uncertainties,such as noise existing in the collected data,the trained controller can still achieve an acceptable gust alleviation ***,considering a flight in which the aircraft mass is constantly changing,the intelligent controller,which continuously learns from new flight data,maintains a good gust alleviation effect throughout the flight.

关键词： Gust alleviation Intelligent control Feedforward control Neural networks Time-varying aircraft

Stabilization/solidification mechanisms of tin tailings and fuming slag-based geopolymers for different heavy metals

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Frontiers of Environmental Science & Engineering 2024年第5期18卷 43-55页

作者： Xian zhou Zhengfu Zhang Hui Yang School of Materials Science and Engineering Kunming University of Science and TechnologyKunming650093China Kunming Metallurgical Research Institute Co. Ltd.Kunming650031China

Tin mine tailings(TMT)and fuming slag(FS)contain many heavy metals(As,Cr,Cu,Zn and Mn)that cause severe pollution to the ***,geopolymers were prepared using TMT,FS and flue gas desulfurization gypsum(FGDG)to immobilize heavy metals,and their compressive strength and heavy metal leaching toxicity were *** was first determined that T4F5(TMT:FS=4:5)sample exhibited the highest compressive strength(7.83 MPa).T4F5 achieved 95%immobilization efficiency for As and Cr,and nearly 100%for Cu,Zn and Mn,showing good immobilization performance.A series of characterization analyses showed that heavy metal cations can balance the charge in the geopolymer and replace Al in the geopolymer structure to form covalent *** addition,about 2%–20%of heavy metal Fe was immobilized in hydration products,heavy metal hydroxides and non-bridging Si–O and Al–O coordination with silica-aluminate ***_(3)^(3−) was oxidized into AsO_(4)^(3−),which may form Ca–As or Fe–As ***_(2)O_(7)^(2−)was converted to CrO_(4)^(2−)under alkaline environment and then combined with OH−to form Cr(OH)3 ***^(2+)may react directly with dissolved silicate to form Mn_(2)SiO_(4) and also form Mn(OH)_(2) *** unstable Mn(OH)_(2) can be further oxidized to MnO_(2).The heavy metal cations were immobilized in the silicoaluminate lattice,while the anions tended to form insoluble *** results may benefit the industry and government for better handling of TMT,FS and solid wastes containing the abovementioned five heavy metals.

关键词： Heavy metals Cementitious materials Tin tailings Stabilization/solidification Redox

Investigation on UV-curing Reprocessable Thermosets Bearing Hindered Urea Bonds and Their Composites with Modified Zinc Oxide Nanoparticles

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Chinese Journal of Polymer Science 2024年第6期42卷 751-765页

作者： Jun-Hao zhou Li-Ming Tang Key Laboratory of Advanced Materials of Ministry of Education of China Department of Chemical EngineeringTsinghua UniversityBeijing100084China

In this study,a series of hindered urea bond(HUB)containing polyurethane-urea methacrylate prepolymers and a none HUB containing polyurethane methacrylate prepolymer were prepared using isobornyl methacrylate as the reactive diluent via one-pot *** prepolymers were characterized fully by various ***,their thermosets were fabricated via UV curing in presence of a photo initiator,and their mechanical property and thermal behavior were investigated and *** from the none HUB containing thermoset,the HUB containing thermosets(defined as PUT)could be recycled and reprocessed by hot press under relatively mild conditions with high recovery ratio of mechanical ***,zinc oxide(ZnO)nanoparticles were modified with 3-(trimethoxysilyl)propyl methacrylate and the modified ZnO(defined as ZnO-TPM)was dispersed and polymerized into PUT matrix to prepare their *** influence of ZnO-TPM on the mechanical performance of the composites was evaluated,which indicated that the Young’s modulus and tensile strength increased gradually to the maximum values at ZnO-TPM content of 1 wt%and then *** composites also displayed good reprocessability with improved recovery ratio compared to the pure PUT *** addition,the composite materials exhibited strong UV absorption capacity,implying their potential application in the circumstance where UV-shielding was required.

关键词： Polyurethane-urea methacrylate Hindered urea bond ZnO nanoparticles Reprocessing UV curing