Six new lanthanide complexes:[Ln(3,4-DEOBA)3(4,4'-DM-2,2'-bipy)]2·2C_(2)H_(5)OH,[Ln=Dy(1),Eu(2),Tb(3),Sm(4),Ho(5),Gd(6);3,4-DEOBA-=3,4-diethoxybenzoate,4,4'-DM-2,2'-bipy=4,4'-dimethyl-2,2'...Six new lanthanide complexes:[Ln(3,4-DEOBA)3(4,4'-DM-2,2'-bipy)]2·2C_(2)H_(5)OH,[Ln=Dy(1),Eu(2),Tb(3),Sm(4),Ho(5),Gd(6);3,4-DEOBA-=3,4-diethoxybenzoate,4,4'-DM-2,2'-bipy=4,4'-dimethyl-2,2'-bipyridine]were successfully synthesized by the volatilization of the solution at room temperature.The crystal structures of six complexes were determined by single-crystal X-ray diffraction technology.The results showed that the complexes all have a binuclear structure,and the structures contain free ethanol molecules.Moreover,the coordination number of the central metal of each structural unit is eight.Adjacent structural units interact with each other through hydrogen bonds and further expand to form 1D chain-like and 2D planar structures.After conducting a systematic study on the luminescence properties of complexes 1-4,their emission and excitation spectra were obtained.Experimental results indicated that the fluorescence lifetimes of complexes 2 and 3 were 0.807 and 0.845 ms,respectively.The emission spectral data of complexes 1-4 were imported into the CIE chromaticity coordinate system,and their corre sponding luminescent regions cover the yellow light,red light,green light,and orange-red light bands,respectively.Within the temperature range of 299.15-1300 K,the thermal decomposition processes of the six complexes were comprehensively analyzed by using TG-DSC/FTIR/MS technology.The hypothesis of the gradual loss of ligand groups during the decomposition process was verified by detecting the escaped gas,3D infrared spectroscopy,and ion fragment information detected by mass spectrometry.The specific decomposition path is as follows:firstly,free ethanol molecules and neutral ligands are removed,and finally,acidic ligands are released;the final product is the corresponding metal oxide.CCDC:2430420,1;2430422,2;2430419,3;2430424,4;2430421,5;2430423,6.展开更多
Two Co(Ⅱ)and Ni(Ⅱ)complexes were synthesized by synergistic coordination of 3,3-diphenylpropionic acid(HDPA)and 2,2′-bipyridylamine(PAm).The structures of complexes[Co(DPA)_(2)(PAm)]·2H_(2)O(1)and[Ni(DPA)_(2)(...Two Co(Ⅱ)and Ni(Ⅱ)complexes were synthesized by synergistic coordination of 3,3-diphenylpropionic acid(HDPA)and 2,2′-bipyridylamine(PAm).The structures of complexes[Co(DPA)_(2)(PAm)]·2H_(2)O(1)and[Ni(DPA)_(2)(PAm)]·2H_(2)O(2)were determined by single-crystal X-ray diffraction,IR spectroscopy,and powder X-ray diffraction.Hirshfeld surface analysis provided quantitative insights into the intermolecular interactions within the complexes,while molecular docking studies elucidated their binding modes and affinities toward urease.Furthermore,the biological activities of both complexes were systematically evaluated through a range of assays,including DNA binding,urease inhibition,antibacterial activity,and in vitro cytotoxicity against cancer cells.Both complexes exhibited binding affinity for DNA and displayed notable urease inhibitory activity.Under in vitro conditions,both complexes showed appreciable cytotoxicity toward HepG2 cells with efficacy comparable to clinically used platinumbased anticancer agents.CCDC:2479943,1;2479944,2.展开更多
Neurodegenerative disorders,including Alzheimer’s disease(AD),Parkinson’s disease(PD),and amyotrophic lateral sclerosis,impose a considerable social and economic burden on society and have dramatic consequences for ...Neurodegenerative disorders,including Alzheimer’s disease(AD),Parkinson’s disease(PD),and amyotrophic lateral sclerosis,impose a considerable social and economic burden on society and have dramatic consequences for individuals and their families.The majority of existing interventions have been found to be capable of only a slight modification of disease progression or to moderately delay significant functional decline in motor,cognitive,or mental domains.展开更多
To address the neglect of seismic performance in conventional double-girder bridge crane optimization,this paper introduces a time-history analysis-based seismic optimization methodology for crane structures.Using a 2...To address the neglect of seismic performance in conventional double-girder bridge crane optimization,this paper introduces a time-history analysis-based seismic optimization methodology for crane structures.Using a 25-t nuclear power crane as a case study,a bridge frame finite element model is established and validated through static analysis,confirming its accurate representation of the physical entity’s mechanical behavior.Furthermore,with bridge mass reduction as the objective and structural strength,stiffness,stability,and seismic mechanical performance as constraints,an optimization model is developed employing the Whale Optimization Algorithm(WOA).展开更多
Dianthus spiculifolius Schur,as an emerging ornamental plant,has extensive applications and economic values.In this study,the DsCBL4 gene was successfully cloned,and its tissue-specific expression,expression patterns ...Dianthus spiculifolius Schur,as an emerging ornamental plant,has extensive applications and economic values.In this study,the DsCBL4 gene was successfully cloned,and its tissue-specific expression,expression patterns under various abiotic stresses,subcellular localization,and bioinformatics analysis of the encoded amino acid sequence were conducted.The results showed that the coding region of the DsCBL4 gene was 675 bp long,encoding 224 amino acids.It had high homology with the amino acids encoded by Amaranthus tricolor,Chenopodium quinoa and Spinacia oleracea.The predicted relative molecular mass of DsCBL4 was 25.61 ku,with an isoelectric point of 4.58,and it had phosphorylation sites,belonging to an unstable hydrophilic protein.Its secondary structure includedα-helices,irregular coils and extended chains.The tertiary structure prediction revealed that DsCBL4 had four EFhand calcium-binding domains necessary for Ca2+binding in plant calmodulin-like proteins and the FPSF motif for calcineurin B-like protein(CBL)-interacting protein kinase(CIPK)activation.The expression level of the DsCBL4 gene showed tissue specificity,with the highest expression in roots.It was induced by drought,low temperature,combined drought and low temperature,salt stress,nitrogen stress,phosphorus stress,calcium ion stress,high temperature stress,and abscisic acid(ABA)stress.Both transient infection in Nicotiana tabacum L.and stable expression in transgenic Arabidopsis thaliana showed that the DsCBL4 protein was localized to the cell membrane.These results suggested that DsCBL4 might be involved in the abiotic stress response of Dianthus spiculifolius through the calcium signaling pathway,providing a theoretical basis for understanding its molecular mechanism.This study provided an important reference for further exploring the role of the DsCBLs gene family in plant stress resistance.展开更多
Underground hydrogen storage has gained interest in recent years due to the enormous demand for clean energy.Hydrogen is more diffusive than air,with a smaller density and lower viscosity.These unique properties intro...Underground hydrogen storage has gained interest in recent years due to the enormous demand for clean energy.Hydrogen is more diffusive than air,with a smaller density and lower viscosity.These unique properties introduce distinctive hydrodynamic phenomena in hydrogen storage,one of which is fingering.Fingering could induce the fluid trapped in small clusters of pores,leading to a dramatic decrease in hydrogen saturation and a lower recovery rate.In this study,numerical simulations are performed at the microscopic scale to understand the evolution of hydrogen saturation and the impacts of injection and withdrawal cycles.Two sets of micromodels with different porosity(0.362 and 0.426)and minimum sizes of pore throats(0.362 mm and 0.181 mm)are developed in the numerical model.A parameter analysis is then conducted to understand the influence of injection velocity(in the range of 10^(-2)m/s to 10^(-5)m/s)and porous structure on the fingering pattern,followed by an image analysis to capture the evolution of the fingering pattern.Viscous fingering,capillary fingering,and crossover fingering are observed and identified under different boundary conditions.The fractal dimension,specific area,mean angle,and entropy of fingers are proposed as geometric descriptors to characterize the shape of the fingering pattern.When porosity increases from 0.362 to 0.426,the saturation of hydrogen increases by 26.2%.Narrower pore throats elevate capillary resistance,which hinders fluid invasion.These results underscore the importance of pore structures and the interaction between viscous and capillary forces for hydrogen recovery efficiency.This work illuminates the influence of the pore structures and the fluid properties on the immiscible displacement of hydrogen and can be further extended to optimize the injection strategy of hydrogen in underground hydrogen storage.展开更多
Structural Health Monitoring(SHM)plays a critical role in ensuring the safety,integrity,longevity and economic efficiency of civil infrastructures.The field has undergone a profound transformation over the last few de...Structural Health Monitoring(SHM)plays a critical role in ensuring the safety,integrity,longevity and economic efficiency of civil infrastructures.The field has undergone a profound transformation over the last few decades,evolving from traditional methods—often reliant on visual inspections—to data-driven intelligent systems.This review paper analyzes this historical trajectory,beginning with the approaches that relied on modal parameters as primary damage indicators.The advent of advanced sensor technologies and increased computational power brings a significant change,making Machine Learning(ML)a viable and powerful tool for damage assessment.More recently,Deep Learning(DL)has emerged as a paradigm shift,allowing for more automated processing of large data sets(such as the structural vibration signals and other types of sensors)with excellent performance and accuracy,often surpassing previous methods.This paper systematically reviews these technological milestones—from traditional vibration-based methods to the current state-of-the-art in deep learning.Finally,it critically examines emerging trends—such as Digital Twins and Transformer-based architectures—and discusses future research directions that will shape the next generation of SHM systems for civil engineering.展开更多
Thin-film structures are widely used in industry due to their advantages in lightweight,flexibility and deployability.This paper investigates the wrinkling deformation pattern of square film subjected to in-plane tors...Thin-film structures are widely used in industry due to their advantages in lightweight,flexibility and deployability.This paper investigates the wrinkling deformation pattern of square film subjected to in-plane torsion through the post-buckling theory of shell,with the geometric nonlinear behavior derived by energy principle and analyzed with finite element method.An equal-sized experimental verification platform is designed and fabricated,and the wrinkling surface of polyimide film driven by rotary motor is reconstructed by 3D-digital image correlation measurement and verified with finite element simulation comparisons.Wrinkling region within the film expands continuously as the torsion proceeds,accompanied by multiple wrinkling configuration transitions throughout the complete evolutionary process.Due to the non-axial symmetry between structure and loading,significant discrepancies arise in amplitude,span and wavelength between different stripes,effects of thickness,torsion radius and pre-stretch on wrinkling pattern configuration are further discussed.This study can provide valuable references for understanding the wrinkling mechanism of hard film under complex torsion loading.展开更多
A detailed understanding of seismicity originating from the Nanga Parbat syntaxis in the northwestern Himalaya is crucial for characterizing the active fault systems and associated neotectonic processes in the region....A detailed understanding of seismicity originating from the Nanga Parbat syntaxis in the northwestern Himalaya is crucial for characterizing the active fault systems and associated neotectonic processes in the region.Continuous earthquake monitoring through local seismic stations enables high-precision results by constraining the velocity structure.In this study,seismogram data from 244 small-magnitude earthquakes are analyzed to delineate the crustal thickness and investigate the source mechanisms beneath the Nanga Parbat syntaxis.The results are achieved with the application of Coupled Hypocenter Velocity Inversion(CHVI)analysis and Time Domain Moment Tensor(TDMT)analysis.The velocity inversion suggests that the Moho discontinuity lies at 60 km depth with an average vP/vS ratio of 1.735±0.017.The minimum 1D velocity model obtained through velocity inversion with least RMS error is further utilized in determining the source mechanism solution.In contrast to earlier studies,which highlighted strike-slip displacement accompanied by reverse dip-slip components,the present research provides a revised interpretation.The moment tensor analysis conducted in this study provides evidence of transtensional deformation associated with neotectonics,attributed to the presence of multiple shear zones.The results of the source mechanism for the selected earthquakes unveiled that the oblique-slip deformation is significantly controlled by the shear stresses coupled with the normal component of dip-slip movement.This is further supported by the higher values of the doublecouple moment tensor(85%),which indicate shear deformation,while the positive value of the compensated linear vector dipole(15%)confirms the presence of a normal component.The coexistence of transpressive and transtensive stresses,together with shallow hypocentral depths and high-amplitude tangential waveforms,can potentially cause devastating impacts in the surroundings of the Nanga Parbat syntaxis.展开更多
With superior structural integrity and design flexibility,3D woven fabrics exhibit unique potential in ballistic protection applications.However,the anisotropic yarn distribution renders traditional 3D woven fabrics s...With superior structural integrity and design flexibility,3D woven fabrics exhibit unique potential in ballistic protection applications.However,the anisotropic yarn distribution renders traditional 3D woven fabrics susceptible to fixed boundaries,which is not conducive to practical applications.Inspired by the motion characteristics of yarn structures,this study investigates a hybrid 3D woven fabric structure that incorporates interlayer warp yarns and normal yarns.Bending stiffness tests,yarn pull-out tests,and ballistic tests are conducted and compared with single-binding yarn structures.Utilizing a validated meso-finite element model,the dynamic deformation and energy absorption mechanisms of the hybrid configuration under impact are elucidated.The results demonstrate that synergistic interactions among various binding yarn structures maintain fabric stability in the absence of boundaries.Normal yarns inhibit horizontal slippage of warp yarns,while multi-layer warp yarns enhance resistance to weft yarn pull-out,thereby facilitating greater yarn participation in direct energy absorption.The hybrid structure exhibited the highest specific energy absorption(SEA)across different boundary conditions,with an average SEA increase of approximately 27%.These insights will facilitate the design of novel hybrid-structured 3D woven fabrics and inform the customization of lightweight protective materials.展开更多
MgO has been shown to facilitate the precipitation of MgO-rich crystalline phases within the MgO-CaO-Al_(2)O_(3)-SiO_(2)(MCAS)glassy inclusion system,which possesses a high liquidus temperature and a significant Young...MgO has been shown to facilitate the precipitation of MgO-rich crystalline phases within the MgO-CaO-Al_(2)O_(3)-SiO_(2)(MCAS)glassy inclusion system,which possesses a high liquidus temperature and a significant Young’s modulus.The underlying linkage between the structural evolution and the crystallization characteristics of the MCAS system was systematically investigated using molecular dynamics simulation and thermodynamic calculation.The results revealed that Mg^(2+) ions played a dual role,constructing networks through the formation of tricluster oxygens while consuming bridging oxygens(BOs)in a mechanism similar to Ca^(2+) ions.However,despite this dual role,the network connectivity was still decreased with the increase in MgO/(MgO+Al_(2)O_(3))(M/(M+A))and CaO/(CaO+SiO_(2))(C/(C+S))ratios,primarily due to the reduction in BOs.This microscopic structural evolution resulted in a reduction in viscosity and an enhancement of crystallization ability.Furthermore,the remarkable diffusion capability of Mg^(2+) ions,coupled with the increased proportion of 6-coordinated Mg^(2+)ions,unveiled the mechanism underlying the precipitation of MgSiO_(3) and Mg_(2)SiO_(4) crystals,which exhibited high Young’s moduli of 165.23 and 196.67 GPa,respectively.To prevent the precipitation of MgO-rich crystalline phases,it was crucial to maintain the M/(M+A)ratio below 0.42 and the C/(C+S)ratio below 0.16 within the MCAS system.展开更多
Economic losses and catastrophic casualties may occur once super high-rise structures are struck by low-probability but high-consequence scenarios of concurrent earthquakes and winds. Therefore, accurately predicting ...Economic losses and catastrophic casualties may occur once super high-rise structures are struck by low-probability but high-consequence scenarios of concurrent earthquakes and winds. Therefore, accurately predicting multi-hazard dynamic responses to super high-rise structures has significant engineering and scientific value. This study performed a parametric global sensitivity analysis (GSA) for multi-hazard dynamic response prediction of super high-rise structures using the multiple-degree-of-freedom shear (MFS) model. Polynomial chaos Kriging (PCK) was introduced to build a surrogate model that allowed GSA to be combined with Sobol’ indices. Monte Carlo simulation (MCS) is also conducted for the comparison to verify the accuracy and efficiency of the PCK method. Parametric sensitivity analysis is performed for a wide range of aleatory uncertainty (intensities of coupled multi-hazard), epistemic uncertainty (bending stiffness, k_(m);shear stiffness, kq;density, ρ;and damping ratio, ξ), probability distribution types, and coefficients of variation. The results indicate that epistemic uncertainty parameters, k_(m), ρ, and ξ dramatically affect the multi-hazard dynamic responses of super high-rise structures;in addition, Sobol’ indices between the normal and lognormal distributions are insignificant, while the variation levels have remarkably influenced the sensitivity indices.展开更多
The connection efficiency of composite pre-tightened multi-tooth joint is low because of uneven load distribution and single load transmission path.In this paper,based on the principle of bio-tooth(suture)structure,co...The connection efficiency of composite pre-tightened multi-tooth joint is low because of uneven load distribution and single load transmission path.In this paper,based on the principle of bio-tooth(suture)structure,combining soft material with fractal,a composite pre-tightened multi-hierarchy tooth joint is proposed,and the bearing performance and failure process of the joint through experiments and finite element method under tensile load.First,the ultimate bearing capacity,load distribution ratio,and failure process of different hierarchies of teeth joints are studied through experiments.Then,the progressive damage models of different hierarchies of tooth joints are established,and experiments verify the validity of the finite element model.Finally,the effects of soft material and increasing tooth hierarchy on the failure process and bearing capacity of composite pre-tightened tooth joints are analyzed by the finite element method.The following conclusions can be drawn:(1)The embedding of soft materials changed the failure process of the joint.Increasing the tooth hierarchy can give the joint more load transfer paths,but the failure process of the joint is complicated.(2)Embedding soft materials and increasing the tooth hierarchy simultaneously can effectively improve the bearing capacity of composite pre-tightened tooth joints,which is 87.8%higher than that of traditional three-tooth joints.展开更多
NLLoc is a nonlinear search positioning method.In this study,we use simulated arrival time data to quantitatively evaluate the NLLoc method from three aspects:arrival time picking accuracy,station distribution,and vel...NLLoc is a nonlinear search positioning method.In this study,we use simulated arrival time data to quantitatively evaluate the NLLoc method from three aspects:arrival time picking accuracy,station distribution,and velocity model.The results show that the NLLoc method exhibits high positioning accuracy and stability in terms of arrival time picking accuracy and station distribution;however,it is sensitive to the velocity model.The positioning accuracy is higher when the velocity model is smaller than the true velocity.We combined absolute and relative positioning methods.First,we use the NLLoc method for absolute positioning of seismic data and then the double difference positioning method for relative positioning to obtain a more accurate relocation result.Furthermore,we used the combined method to locate the earthquake sequence after collecting dense seismic array data on the Luanzhou M_(S)4.3 earthquake that occurred on April 16,2021,in Hebei Province.By fitting the fault plane with the relocated earthquake sequences,the results show that the strike and dip angles of the seismogenic fault of the Luanzhou M_(S)4.3 earthquake are 208.5°and 85.6°,respectively.This indicates a high-dip angle fault with North-North-East strike and North-West dip directions.Furthermore,we infer that the seismogenic fault of the Luanzhou M_(S)4.3 earthquake is the Lulong fault.展开更多
According to the innate characteristic of four types of furnace, the copper flash continuous smelting （CFCS） furnace can be considered a synthetic reactor of two relatively independent processes： flash matte smelti...According to the innate characteristic of four types of furnace, the copper flash continuous smelting （CFCS） furnace can be considered a synthetic reactor of two relatively independent processes： flash matte smelting process （FMSP） and copper continuous converting process （CCCP）. Then, the CFCS thermodynamic model was proposed by establishing the multi-phase equilibrium model of FMSP and the local-equilibrium model of CCCP, respectively, and by combining them through the smelting intermediates. Subsequently, the influences of the furnace structures were investigated using the model on the formation of blister copper, the Fe3O4 behavior, the copper loss in slag and the copper recovery rate. The results show that the type D furnace, with double flues and a slag partition wall, is an ideal CFCS reactor compared with the other three types furnaces. For CFCS, it is effective to design a partition wall in the furnace to make FMSP and CCCP perform in two relatively independent zones, respectively, and to make smelting gas and converting gas discharge from respective flues.展开更多
Methods and procedures of three-dimensional （3D） characterization of the pore structure features in the packed ore particle bed are focused. X-ray computed tomography was applied to deriving the cross-sectional imag...Methods and procedures of three-dimensional （3D） characterization of the pore structure features in the packed ore particle bed are focused. X-ray computed tomography was applied to deriving the cross-sectional images of specimens with single particle size of 1-2, 2-3, 3-4, 4-5, 5-6, 6-7, 7-8, 8-9, 9-10 ram. Based on the in-house developed 3D image analysis programs using Matlab, the volume porosity, pore size distribution and degree of connectivity were calculated and analyzed in detail. The results indicate that the volume porosity, the mean diameter of pores and the effective pore size （d50） increase with the increasing of particle size. Lognormal distribution or Gauss distribution is mostly suitable to model the pore size distribution. The degree of connectivity investigated on the basis of cluster-labeling algorithm also increases with increasing the particle size approximately.展开更多
The effect of structure,elastic modulus and thickness of lower modulus layer in porous titanium implants on the stress distribution at the implant-bone interface was investigated.Three-dimensional finite element model...The effect of structure,elastic modulus and thickness of lower modulus layer in porous titanium implants on the stress distribution at the implant-bone interface was investigated.Three-dimensional finite element models of different titanium implants were constructed.The structures of the implants included the whole lower modulus style （No.1）,bio-mimetic style （No.2）,the whole lower modulus style in cancellous bone （No.3） and the whole dense style No.4.The stress distributions at bone-implant interface under static loading were analyzed using Ansys Workbench 10.0 software.The results indicated that the distribution of interface stress is strongly depended on the structure of the implants.The maximum stresses in cancellous bone and root region of implant No.2 are lower than those in the other three implants.A decrease in the modulus of the low modulus layer facilitates the interface stress transferring.Increasing the thickness of the low modulus layer can reduce the stress and induce a more uniform stress distribution at the interface.Among the four implants,biomimetic style implant No.2 is superior in transferring implant-bone interface stress to surrounding bones.展开更多
In western China seismic wave fields are very complicated and have low signal to noise ratio.In this paper,we focus on complex wave field research by forward modeling and indicate that density should not be ignored in...In western China seismic wave fields are very complicated and have low signal to noise ratio.In this paper,we focus on complex wave field research by forward modeling and indicate that density should not be ignored in wave field simulation if the subsurface physical properties are quite different.We use the acoustic wave equation with density in the staggered finite-difference method to simulate the wave fields.For this purpose a complicated geologic structural model with rugged surfaces,near-surface low-velocity layers,and high-velocity outcropping layers was designed.Based on the instantaneous wave field distribution,we analyzed the mechanism forming complex wave fields.The influence of low velocity layers on the wave field is very strong.A strong waveguide occurs between the top and base of a low velocity layer,producing multiples which penetrate into the earth and form strong complex wave fields in addition to reflections from subsurface interfaces.For verifying the correctness of the simulated wave fields,prestack depth migration was performed using different algorithms from the forward modeling.The structure revealed by the stacked migration profile is same as the known structure.展开更多
The design of counter-rotating turbine is one of new techniques to improve the thrust-weight ratio of jet propulsion engines.Numerical analysis of a low pressure（LP）counter-rotating turbine rotor blade is presented ...The design of counter-rotating turbine is one of new techniques to improve the thrust-weight ratio of jet propulsion engines.Numerical analysis of a low pressure（LP）counter-rotating turbine rotor blade is presented by using ANSYS/CFX software.Interaction of aerodynamics and solid mechanics coupling in the computation is applied.In some rating of turbine,stress distribution and vibration characteristics of low pressure turbine（LPT）blade are computed.The wake aerodynamic forces and LPT blade vibration are transformed in frequency domain using fast Fourier transform（FFT）method.The results show that under wake aerodynamic force excitation,the first order modal vibration is more easily aroused and the higher order response cannot be ignored.Moreover,with different temperature fields,the vibration responses of blade are also different.展开更多
[Objective] The study was to analyze the structure and function of HpaGXoo and the relationship between the two.[Method] Some related bioinformatics analysis software on internet such as NPSA,Swiss-Model,SAPS and Inte...[Objective] The study was to analyze the structure and function of HpaGXoo and the relationship between the two.[Method] Some related bioinformatics analysis software on internet such as NPSA,Swiss-Model,SAPS and InterPro Scan were adopted to analyze the structure and predict its function.[Result] HpaGXoo consists of 139 amino acids,and has many alpha-helical and coiled structure,no signal peptide on N-terminal and no transmembrane structure.It locates in bacterial cytoplasm.[Conclusion] The study will lay ...展开更多
文摘Six new lanthanide complexes:[Ln(3,4-DEOBA)3(4,4'-DM-2,2'-bipy)]2·2C_(2)H_(5)OH,[Ln=Dy(1),Eu(2),Tb(3),Sm(4),Ho(5),Gd(6);3,4-DEOBA-=3,4-diethoxybenzoate,4,4'-DM-2,2'-bipy=4,4'-dimethyl-2,2'-bipyridine]were successfully synthesized by the volatilization of the solution at room temperature.The crystal structures of six complexes were determined by single-crystal X-ray diffraction technology.The results showed that the complexes all have a binuclear structure,and the structures contain free ethanol molecules.Moreover,the coordination number of the central metal of each structural unit is eight.Adjacent structural units interact with each other through hydrogen bonds and further expand to form 1D chain-like and 2D planar structures.After conducting a systematic study on the luminescence properties of complexes 1-4,their emission and excitation spectra were obtained.Experimental results indicated that the fluorescence lifetimes of complexes 2 and 3 were 0.807 and 0.845 ms,respectively.The emission spectral data of complexes 1-4 were imported into the CIE chromaticity coordinate system,and their corre sponding luminescent regions cover the yellow light,red light,green light,and orange-red light bands,respectively.Within the temperature range of 299.15-1300 K,the thermal decomposition processes of the six complexes were comprehensively analyzed by using TG-DSC/FTIR/MS technology.The hypothesis of the gradual loss of ligand groups during the decomposition process was verified by detecting the escaped gas,3D infrared spectroscopy,and ion fragment information detected by mass spectrometry.The specific decomposition path is as follows:firstly,free ethanol molecules and neutral ligands are removed,and finally,acidic ligands are released;the final product is the corresponding metal oxide.CCDC:2430420,1;2430422,2;2430419,3;2430424,4;2430421,5;2430423,6.
文摘Two Co(Ⅱ)and Ni(Ⅱ)complexes were synthesized by synergistic coordination of 3,3-diphenylpropionic acid(HDPA)and 2,2′-bipyridylamine(PAm).The structures of complexes[Co(DPA)_(2)(PAm)]·2H_(2)O(1)and[Ni(DPA)_(2)(PAm)]·2H_(2)O(2)were determined by single-crystal X-ray diffraction,IR spectroscopy,and powder X-ray diffraction.Hirshfeld surface analysis provided quantitative insights into the intermolecular interactions within the complexes,while molecular docking studies elucidated their binding modes and affinities toward urease.Furthermore,the biological activities of both complexes were systematically evaluated through a range of assays,including DNA binding,urease inhibition,antibacterial activity,and in vitro cytotoxicity against cancer cells.Both complexes exhibited binding affinity for DNA and displayed notable urease inhibitory activity.Under in vitro conditions,both complexes showed appreciable cytotoxicity toward HepG2 cells with efficacy comparable to clinically used platinumbased anticancer agents.CCDC:2479943,1;2479944,2.
文摘Neurodegenerative disorders,including Alzheimer’s disease(AD),Parkinson’s disease(PD),and amyotrophic lateral sclerosis,impose a considerable social and economic burden on society and have dramatic consequences for individuals and their families.The majority of existing interventions have been found to be capable of only a slight modification of disease progression or to moderately delay significant functional decline in motor,cognitive,or mental domains.
文摘To address the neglect of seismic performance in conventional double-girder bridge crane optimization,this paper introduces a time-history analysis-based seismic optimization methodology for crane structures.Using a 25-t nuclear power crane as a case study,a bridge frame finite element model is established and validated through static analysis,confirming its accurate representation of the physical entity’s mechanical behavior.Furthermore,with bridge mass reduction as the objective and structural strength,stiffness,stability,and seismic mechanical performance as constraints,an optimization model is developed employing the Whale Optimization Algorithm(WOA).
基金Supported by the National Key R&D Program(2022YFF1300500)the Spring Goose Support Program(CYQN24018)the National Natural Science Foundation of China(32572123)。
文摘Dianthus spiculifolius Schur,as an emerging ornamental plant,has extensive applications and economic values.In this study,the DsCBL4 gene was successfully cloned,and its tissue-specific expression,expression patterns under various abiotic stresses,subcellular localization,and bioinformatics analysis of the encoded amino acid sequence were conducted.The results showed that the coding region of the DsCBL4 gene was 675 bp long,encoding 224 amino acids.It had high homology with the amino acids encoded by Amaranthus tricolor,Chenopodium quinoa and Spinacia oleracea.The predicted relative molecular mass of DsCBL4 was 25.61 ku,with an isoelectric point of 4.58,and it had phosphorylation sites,belonging to an unstable hydrophilic protein.Its secondary structure includedα-helices,irregular coils and extended chains.The tertiary structure prediction revealed that DsCBL4 had four EFhand calcium-binding domains necessary for Ca2+binding in plant calmodulin-like proteins and the FPSF motif for calcineurin B-like protein(CBL)-interacting protein kinase(CIPK)activation.The expression level of the DsCBL4 gene showed tissue specificity,with the highest expression in roots.It was induced by drought,low temperature,combined drought and low temperature,salt stress,nitrogen stress,phosphorus stress,calcium ion stress,high temperature stress,and abscisic acid(ABA)stress.Both transient infection in Nicotiana tabacum L.and stable expression in transgenic Arabidopsis thaliana showed that the DsCBL4 protein was localized to the cell membrane.These results suggested that DsCBL4 might be involved in the abiotic stress response of Dianthus spiculifolius through the calcium signaling pathway,providing a theoretical basis for understanding its molecular mechanism.This study provided an important reference for further exploring the role of the DsCBLs gene family in plant stress resistance.
基金supported by the National Key Research and Development Project(Grant No.2023YFE0110900)the National Natural Science Foundation of China(Grant Nos.42320104003,42477168).
文摘Underground hydrogen storage has gained interest in recent years due to the enormous demand for clean energy.Hydrogen is more diffusive than air,with a smaller density and lower viscosity.These unique properties introduce distinctive hydrodynamic phenomena in hydrogen storage,one of which is fingering.Fingering could induce the fluid trapped in small clusters of pores,leading to a dramatic decrease in hydrogen saturation and a lower recovery rate.In this study,numerical simulations are performed at the microscopic scale to understand the evolution of hydrogen saturation and the impacts of injection and withdrawal cycles.Two sets of micromodels with different porosity(0.362 and 0.426)and minimum sizes of pore throats(0.362 mm and 0.181 mm)are developed in the numerical model.A parameter analysis is then conducted to understand the influence of injection velocity(in the range of 10^(-2)m/s to 10^(-5)m/s)and porous structure on the fingering pattern,followed by an image analysis to capture the evolution of the fingering pattern.Viscous fingering,capillary fingering,and crossover fingering are observed and identified under different boundary conditions.The fractal dimension,specific area,mean angle,and entropy of fingers are proposed as geometric descriptors to characterize the shape of the fingering pattern.When porosity increases from 0.362 to 0.426,the saturation of hydrogen increases by 26.2%.Narrower pore throats elevate capillary resistance,which hinders fluid invasion.These results underscore the importance of pore structures and the interaction between viscous and capillary forces for hydrogen recovery efficiency.This work illuminates the influence of the pore structures and the fluid properties on the immiscible displacement of hydrogen and can be further extended to optimize the injection strategy of hydrogen in underground hydrogen storage.
基金The authors would like to thank CNPq(Conselho Nacional de Desenvolvimento Científico e Tecnológico)—grants 407256/2022-9,303550/2025-2,402533/2023-2 and 303982/2022-5FAPEMIG(Fundação de AmparoàPesquisa do Estado de Minas Gerais)—grants APQ-00032-24 and APD-01113-25 for their financial support.
文摘Structural Health Monitoring(SHM)plays a critical role in ensuring the safety,integrity,longevity and economic efficiency of civil infrastructures.The field has undergone a profound transformation over the last few decades,evolving from traditional methods—often reliant on visual inspections—to data-driven intelligent systems.This review paper analyzes this historical trajectory,beginning with the approaches that relied on modal parameters as primary damage indicators.The advent of advanced sensor technologies and increased computational power brings a significant change,making Machine Learning(ML)a viable and powerful tool for damage assessment.More recently,Deep Learning(DL)has emerged as a paradigm shift,allowing for more automated processing of large data sets(such as the structural vibration signals and other types of sensors)with excellent performance and accuracy,often surpassing previous methods.This paper systematically reviews these technological milestones—from traditional vibration-based methods to the current state-of-the-art in deep learning.Finally,it critically examines emerging trends—such as Digital Twins and Transformer-based architectures—and discusses future research directions that will shape the next generation of SHM systems for civil engineering.
基金supported by the National Natural Science Foundation of China(Grant No.12472347).
文摘Thin-film structures are widely used in industry due to their advantages in lightweight,flexibility and deployability.This paper investigates the wrinkling deformation pattern of square film subjected to in-plane torsion through the post-buckling theory of shell,with the geometric nonlinear behavior derived by energy principle and analyzed with finite element method.An equal-sized experimental verification platform is designed and fabricated,and the wrinkling surface of polyimide film driven by rotary motor is reconstructed by 3D-digital image correlation measurement and verified with finite element simulation comparisons.Wrinkling region within the film expands continuously as the torsion proceeds,accompanied by multiple wrinkling configuration transitions throughout the complete evolutionary process.Due to the non-axial symmetry between structure and loading,significant discrepancies arise in amplitude,span and wavelength between different stripes,effects of thickness,torsion radius and pre-stretch on wrinkling pattern configuration are further discussed.This study can provide valuable references for understanding the wrinkling mechanism of hard film under complex torsion loading.
文摘A detailed understanding of seismicity originating from the Nanga Parbat syntaxis in the northwestern Himalaya is crucial for characterizing the active fault systems and associated neotectonic processes in the region.Continuous earthquake monitoring through local seismic stations enables high-precision results by constraining the velocity structure.In this study,seismogram data from 244 small-magnitude earthquakes are analyzed to delineate the crustal thickness and investigate the source mechanisms beneath the Nanga Parbat syntaxis.The results are achieved with the application of Coupled Hypocenter Velocity Inversion(CHVI)analysis and Time Domain Moment Tensor(TDMT)analysis.The velocity inversion suggests that the Moho discontinuity lies at 60 km depth with an average vP/vS ratio of 1.735±0.017.The minimum 1D velocity model obtained through velocity inversion with least RMS error is further utilized in determining the source mechanism solution.In contrast to earlier studies,which highlighted strike-slip displacement accompanied by reverse dip-slip components,the present research provides a revised interpretation.The moment tensor analysis conducted in this study provides evidence of transtensional deformation associated with neotectonics,attributed to the presence of multiple shear zones.The results of the source mechanism for the selected earthquakes unveiled that the oblique-slip deformation is significantly controlled by the shear stresses coupled with the normal component of dip-slip movement.This is further supported by the higher values of the doublecouple moment tensor(85%),which indicate shear deformation,while the positive value of the compensated linear vector dipole(15%)confirms the presence of a normal component.The coexistence of transpressive and transtensive stresses,together with shallow hypocentral depths and high-amplitude tangential waveforms,can potentially cause devastating impacts in the surroundings of the Nanga Parbat syntaxis.
基金supports from National Key R&D Program for Young Scientists of China(No.2022YFC3080900)the opening project of State Key Laboratory of Explosion Science and Safety Protection,Beijing Institute of Technology(No.KFJJ25-25M).
文摘With superior structural integrity and design flexibility,3D woven fabrics exhibit unique potential in ballistic protection applications.However,the anisotropic yarn distribution renders traditional 3D woven fabrics susceptible to fixed boundaries,which is not conducive to practical applications.Inspired by the motion characteristics of yarn structures,this study investigates a hybrid 3D woven fabric structure that incorporates interlayer warp yarns and normal yarns.Bending stiffness tests,yarn pull-out tests,and ballistic tests are conducted and compared with single-binding yarn structures.Utilizing a validated meso-finite element model,the dynamic deformation and energy absorption mechanisms of the hybrid configuration under impact are elucidated.The results demonstrate that synergistic interactions among various binding yarn structures maintain fabric stability in the absence of boundaries.Normal yarns inhibit horizontal slippage of warp yarns,while multi-layer warp yarns enhance resistance to weft yarn pull-out,thereby facilitating greater yarn participation in direct energy absorption.The hybrid structure exhibited the highest specific energy absorption(SEA)across different boundary conditions,with an average SEA increase of approximately 27%.These insights will facilitate the design of novel hybrid-structured 3D woven fabrics and inform the customization of lightweight protective materials.
基金support from the National Key R&D Program of China(Grant Nos.2023YFB3709900 and 2023YFB3709903)the National Natural Science Foundation of China(Grant Nos.52174293 and U22A20171)+1 种基金the High Steel Center(HSC)at North China University of TechnologyUniversity of Science and Technology Beijing(USTB).
文摘MgO has been shown to facilitate the precipitation of MgO-rich crystalline phases within the MgO-CaO-Al_(2)O_(3)-SiO_(2)(MCAS)glassy inclusion system,which possesses a high liquidus temperature and a significant Young’s modulus.The underlying linkage between the structural evolution and the crystallization characteristics of the MCAS system was systematically investigated using molecular dynamics simulation and thermodynamic calculation.The results revealed that Mg^(2+) ions played a dual role,constructing networks through the formation of tricluster oxygens while consuming bridging oxygens(BOs)in a mechanism similar to Ca^(2+) ions.However,despite this dual role,the network connectivity was still decreased with the increase in MgO/(MgO+Al_(2)O_(3))(M/(M+A))and CaO/(CaO+SiO_(2))(C/(C+S))ratios,primarily due to the reduction in BOs.This microscopic structural evolution resulted in a reduction in viscosity and an enhancement of crystallization ability.Furthermore,the remarkable diffusion capability of Mg^(2+) ions,coupled with the increased proportion of 6-coordinated Mg^(2+)ions,unveiled the mechanism underlying the precipitation of MgSiO_(3) and Mg_(2)SiO_(4) crystals,which exhibited high Young’s moduli of 165.23 and 196.67 GPa,respectively.To prevent the precipitation of MgO-rich crystalline phases,it was crucial to maintain the M/(M+A)ratio below 0.42 and the C/(C+S)ratio below 0.16 within the MCAS system.
基金Dalian Municipal Natural Science Foundation under Grant No.2019RD01。
文摘Economic losses and catastrophic casualties may occur once super high-rise structures are struck by low-probability but high-consequence scenarios of concurrent earthquakes and winds. Therefore, accurately predicting multi-hazard dynamic responses to super high-rise structures has significant engineering and scientific value. This study performed a parametric global sensitivity analysis (GSA) for multi-hazard dynamic response prediction of super high-rise structures using the multiple-degree-of-freedom shear (MFS) model. Polynomial chaos Kriging (PCK) was introduced to build a surrogate model that allowed GSA to be combined with Sobol’ indices. Monte Carlo simulation (MCS) is also conducted for the comparison to verify the accuracy and efficiency of the PCK method. Parametric sensitivity analysis is performed for a wide range of aleatory uncertainty (intensities of coupled multi-hazard), epistemic uncertainty (bending stiffness, k_(m);shear stiffness, kq;density, ρ;and damping ratio, ξ), probability distribution types, and coefficients of variation. The results indicate that epistemic uncertainty parameters, k_(m), ρ, and ξ dramatically affect the multi-hazard dynamic responses of super high-rise structures;in addition, Sobol’ indices between the normal and lognormal distributions are insignificant, while the variation levels have remarkably influenced the sensitivity indices.
基金funded by the National Natural Science Foundation of China(52478138).
文摘The connection efficiency of composite pre-tightened multi-tooth joint is low because of uneven load distribution and single load transmission path.In this paper,based on the principle of bio-tooth(suture)structure,combining soft material with fractal,a composite pre-tightened multi-hierarchy tooth joint is proposed,and the bearing performance and failure process of the joint through experiments and finite element method under tensile load.First,the ultimate bearing capacity,load distribution ratio,and failure process of different hierarchies of teeth joints are studied through experiments.Then,the progressive damage models of different hierarchies of tooth joints are established,and experiments verify the validity of the finite element model.Finally,the effects of soft material and increasing tooth hierarchy on the failure process and bearing capacity of composite pre-tightened tooth joints are analyzed by the finite element method.The following conclusions can be drawn:(1)The embedding of soft materials changed the failure process of the joint.Increasing the tooth hierarchy can give the joint more load transfer paths,but the failure process of the joint is complicated.(2)Embedding soft materials and increasing the tooth hierarchy simultaneously can effectively improve the bearing capacity of composite pre-tightened tooth joints,which is 87.8%higher than that of traditional three-tooth joints.
基金Supported by the Foundation:This research project is jointly supported by Hebei Provincial Science and Technology Program(No.22375406D)The Earthquake Science and Technology Program of Hebei Province(No.DZ2023120500009,DZ2024120500001).
文摘NLLoc is a nonlinear search positioning method.In this study,we use simulated arrival time data to quantitatively evaluate the NLLoc method from three aspects:arrival time picking accuracy,station distribution,and velocity model.The results show that the NLLoc method exhibits high positioning accuracy and stability in terms of arrival time picking accuracy and station distribution;however,it is sensitive to the velocity model.The positioning accuracy is higher when the velocity model is smaller than the true velocity.We combined absolute and relative positioning methods.First,we use the NLLoc method for absolute positioning of seismic data and then the double difference positioning method for relative positioning to obtain a more accurate relocation result.Furthermore,we used the combined method to locate the earthquake sequence after collecting dense seismic array data on the Luanzhou M_(S)4.3 earthquake that occurred on April 16,2021,in Hebei Province.By fitting the fault plane with the relocated earthquake sequences,the results show that the strike and dip angles of the seismogenic fault of the Luanzhou M_(S)4.3 earthquake are 208.5°and 85.6°,respectively.This indicates a high-dip angle fault with North-North-East strike and North-West dip directions.Furthermore,we infer that the seismogenic fault of the Luanzhou M_(S)4.3 earthquake is the Lulong fault.
基金Project (50904027) supported by the National Natural Science Foundation of ChinaProject (2013BAB03B05) supported by the National Key Technology R&D Program of China+1 种基金Project (20133BCB23018) supported by the Foundation for Young Scientist(Jinggang Star)of Jiangxi Province,ChinaProject (2012ZBAB206002) supported by the Natural Science Foundation of Jiangxi Province,China
文摘According to the innate characteristic of four types of furnace, the copper flash continuous smelting （CFCS） furnace can be considered a synthetic reactor of two relatively independent processes： flash matte smelting process （FMSP） and copper continuous converting process （CCCP）. Then, the CFCS thermodynamic model was proposed by establishing the multi-phase equilibrium model of FMSP and the local-equilibrium model of CCCP, respectively, and by combining them through the smelting intermediates. Subsequently, the influences of the furnace structures were investigated using the model on the formation of blister copper, the Fe3O4 behavior, the copper loss in slag and the copper recovery rate. The results show that the type D furnace, with double flues and a slag partition wall, is an ideal CFCS reactor compared with the other three types furnaces. For CFCS, it is effective to design a partition wall in the furnace to make FMSP and CCCP perform in two relatively independent zones, respectively, and to make smelting gas and converting gas discharge from respective flues.
基金Projects(50934002,51074013,51304076,51104100)supported by the National Natural Science Foundation of ChinaProject(IRT0950)supported by the Program for Changjiang Scholars Innovative Research Team in Universities,ChinaProject(2012M510007)supported by China Postdoctoral Science Foundation
文摘Methods and procedures of three-dimensional （3D） characterization of the pore structure features in the packed ore particle bed are focused. X-ray computed tomography was applied to deriving the cross-sectional images of specimens with single particle size of 1-2, 2-3, 3-4, 4-5, 5-6, 6-7, 7-8, 8-9, 9-10 ram. Based on the in-house developed 3D image analysis programs using Matlab, the volume porosity, pore size distribution and degree of connectivity were calculated and analyzed in detail. The results indicate that the volume porosity, the mean diameter of pores and the effective pore size （d50） increase with the increasing of particle size. Lognormal distribution or Gauss distribution is mostly suitable to model the pore size distribution. The degree of connectivity investigated on the basis of cluster-labeling algorithm also increases with increasing the particle size approximately.
基金Project(30770576) supported by the National Natural Science Foundation of ChinaProject(2007AA03Z114) supported by Hi-tech Research and Development Program of ChinaProject supported by State Key Laboratory of Powder Metallurgy,China
文摘The effect of structure,elastic modulus and thickness of lower modulus layer in porous titanium implants on the stress distribution at the implant-bone interface was investigated.Three-dimensional finite element models of different titanium implants were constructed.The structures of the implants included the whole lower modulus style （No.1）,bio-mimetic style （No.2）,the whole lower modulus style in cancellous bone （No.3） and the whole dense style No.4.The stress distributions at bone-implant interface under static loading were analyzed using Ansys Workbench 10.0 software.The results indicated that the distribution of interface stress is strongly depended on the structure of the implants.The maximum stresses in cancellous bone and root region of implant No.2 are lower than those in the other three implants.A decrease in the modulus of the low modulus layer facilitates the interface stress transferring.Increasing the thickness of the low modulus layer can reduce the stress and induce a more uniform stress distribution at the interface.Among the four implants,biomimetic style implant No.2 is superior in transferring implant-bone interface stress to surrounding bones.
基金supported in part by the National Natural Science Foundation of China(Grant No.40974069)PetroChina Innovation Foundation(Grant No.2009D-5006-03-01)+1 种基金National Key Basic Research Development Program(GrantNo.2007CB209601)National Major Science and Technology Program(Grant Nos.2008ZX05010-002 and 2008ZX05024-001)
文摘In western China seismic wave fields are very complicated and have low signal to noise ratio.In this paper,we focus on complex wave field research by forward modeling and indicate that density should not be ignored in wave field simulation if the subsurface physical properties are quite different.We use the acoustic wave equation with density in the staggered finite-difference method to simulate the wave fields.For this purpose a complicated geologic structural model with rugged surfaces,near-surface low-velocity layers,and high-velocity outcropping layers was designed.Based on the instantaneous wave field distribution,we analyzed the mechanism forming complex wave fields.The influence of low velocity layers on the wave field is very strong.A strong waveguide occurs between the top and base of a low velocity layer,producing multiples which penetrate into the earth and form strong complex wave fields in addition to reflections from subsurface interfaces.For verifying the correctness of the simulated wave fields,prestack depth migration was performed using different algorithms from the forward modeling.The structure revealed by the stacked migration profile is same as the known structure.
文摘The design of counter-rotating turbine is one of new techniques to improve the thrust-weight ratio of jet propulsion engines.Numerical analysis of a low pressure（LP）counter-rotating turbine rotor blade is presented by using ANSYS/CFX software.Interaction of aerodynamics and solid mechanics coupling in the computation is applied.In some rating of turbine,stress distribution and vibration characteristics of low pressure turbine（LPT）blade are computed.The wake aerodynamic forces and LPT blade vibration are transformed in frequency domain using fast Fourier transform（FFT）method.The results show that under wake aerodynamic force excitation,the first order modal vibration is more easily aroused and the higher order response cannot be ignored.Moreover,with different temperature fields,the vibration responses of blade are also different.
基金Supported by Langfang Teachers College Research Grant(LSZB200803)~~
文摘[Objective] The study was to analyze the structure and function of HpaGXoo and the relationship between the two.[Method] Some related bioinformatics analysis software on internet such as NPSA,Swiss-Model,SAPS and InterPro Scan were adopted to analyze the structure and predict its function.[Result] HpaGXoo consists of 139 amino acids,and has many alpha-helical and coiled structure,no signal peptide on N-terminal and no transmembrane structure.It locates in bacterial cytoplasm.[Conclusion] The study will lay ...
