Through different preparation technology, this paper reports that the needle coke is prepared with coal-tar pitch under the effect of magnetic field and ultrasonic cavitation. It studies the effect of physical disturb...Through different preparation technology, this paper reports that the needle coke is prepared with coal-tar pitch under the effect of magnetic field and ultrasonic cavitation. It studies the effect of physical disturbance on the structure of needle coke. The structure of needle coke is characterized by scanning electron microscope and x-ray diffractometer, and the influence mechanism is analysed. Results showed that the structure and property of needle coke could be effectively improved by magnetic field and ultrasonic cavitations, such as degree of order, degree of graphitization and crystallization. Comparatively speaking, the effect of magnetic field was greater. The graphitization degree of needle coke prepared under the effect of magnetic field is up to 45.35%.展开更多
Pinus yunnanensis Franch. is an particular conifer tree species in Yunnan-Guizhou plateau in south- west China. The morphological and anatomical traits of needles are important to evaluate geographic variation and pop...Pinus yunnanensis Franch. is an particular conifer tree species in Yunnan-Guizhou plateau in south- west China. The morphological and anatomical traits of needles are important to evaluate geographic variation and population dynamics of conifer species. Seedlings from seven populations of P. yunnanensis were analyzed, look- ing at 22 morphological and anatomical needle traits. The results showed that variations among and within popula- tions were significantly different for all traits and the variance components within populations were generally higher than that among populations in the most tested needle traits. The proportions of three-needle fascicle were significantly different among populations. The traits related to needle size in both morphology and anatomy were positive with latitude and negative with annual temperature and precipitation. Ratio indices, including mesophyllarea/vascular bundle area, mesophyll area/resin canals area, vascular bundle area/resin canals area and mesophyU area/（resin canals area and vascular bundle area）, were negatively correlated with elevation and positively corre- lated with the annual mean temperature, showing some fitness feature for the populations. Needle traits were more significantly correlated with longitude than with other four environmental factors. Needle length was significantly correlated with almost all environmental factors. First four principal components accounted for 81.596 % of the variation with eigenvalues 〉1; the differences among populations were mainly dependent on needle width, stomatal density, section areas of vascular bundle, total resin canals, and mesophyll, as well as area ratio traits. Seven populations were divided into three categories by Euclidean distance. Variations in needle traits among the populations have shown systematic microevolution in terms of geographic impact on P. yunnanensis. This study would provide empirical data to characterize adaptation and genetic variation of P. yunnanensis, which would be helpful for management of genetic resources and reason- able utilization of them in future.展开更多
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
To elucidate the effect of calcite-regulated activated carbon(AC)structure on low-temperature denitrification performance of SCR catalysts,this work prepared a series of Mn-Ce/De-AC-xCaCO_(3)(x is the calcite content ...To elucidate the effect of calcite-regulated activated carbon(AC)structure on low-temperature denitrification performance of SCR catalysts,this work prepared a series of Mn-Ce/De-AC-xCaCO_(3)(x is the calcite content in coal)catalysts were prepared by the incipient wetness impregnation method,followed by acid washing to remove calcium-containing minerals.Comprehensive characterization and low-temperature denitrification tests revealed that calcite-induced structural modulation of coal-derived AC significantly enhances catalytic activity.Specifically,NO conversion increased from 88.3%of Mn-Ce/De-AC to 91.7%of Mn-Ce/De-AC-1CaCO_(3)(210℃).The improved SCR denitrification activity results from the enhancement of physicochemical properties including higher Mn^(4+)content and Ce^(4+)/Ce^(3+)ratio,an abundance of chemisorbed oxygen and acidic sites,which could strengthen the SCR reaction pathways(richer NH_(3)activated species and bidentate nitrate active species).Therefore,NO removal is enhanced.展开更多
In this study,a novel polysaccharide GPA-G 2-H was derived from ginseng.Furthermore,the coherent study of its structural characteristics,fermented characteristics in vitro,as well as antioxidant mechanism of fermented...In this study,a novel polysaccharide GPA-G 2-H was derived from ginseng.Furthermore,the coherent study of its structural characteristics,fermented characteristics in vitro,as well as antioxidant mechanism of fermented product FGPA-G 2-H on Aβ25-35-induced PC 12 cells were explored.The structure of GPA-G 2-H was determined by means of zeta potential analysis,FTIR,HPLC,XRD,GC-MS and NMR.The backbone of GPA-G 2-H was mainly composed of→4)-α-D-Glcp-(1→with branches substituted at O-3.Notably,GPA-G 2-H was degraded by intestinal microbiota in vitro with total sugar content and pH value decreasing,and short-chain fatty acids(SCFAs)increasing.Moreover,GPA-G 2-H significantly promoted the proliferation of Lactobacillus,Muribaculaceae and Weissella,thereby making positive alterations in intestinal microbiota composition.Additionally,FGPA-G 2-H activated the Nrf 2/HO-1 signaling pathway,enhanced HO-1,NQO 1,SOD and GSH-Px,while inhabited Keap 1,MDA and LDH,which alleviated Aβ-induced oxidative stress in PC 12 cells.These provide a solid theoretical basis for the further development of ginseng polysaccharides as functional food and antioxidant drugs.展开更多
Anchovies are key forage species in coastal and pelagic food webs,playing crucial ecological and commercial roles in marine ecosystems.Encrasicholina punctifer is a commercially and ecologically important species,yet ...Anchovies are key forage species in coastal and pelagic food webs,playing crucial ecological and commercial roles in marine ecosystems.Encrasicholina punctifer is a commercially and ecologically important species,yet little is known about its osteological development characteristics.Understanding these ontogenetic patterns is essential for explaining phylogenetic relationships within Clupeiformes,informing larval identification in ichthyoplankton surveys,and enhancing aquaculture practices.This study describes the ontogenetic characteristics of the appendicular and median skeletons and fin supports in E.punctifer larvae and juveniles,providing quantitative ontogenetic timelines to address gaps in engraulid developmental biology and contribute to teleost ontogeny research.Larval and juvenile specimens of E.punctifer;size range:3.00-34.56 mm standard length(SL)and notochord length(NL)collected from the Philippine Sea were processed using the standard Alizarin red and Alcian blue clearing-and-staining technique to differentiate ossified and cartilaginous elements.Specimens were examined under a stereo microscope and imaged with an HTC1600ISP digital camera for detailed morphological analysis of skeletal structures.Caudal complex development was evident by 5.55 mm NL,with the initial appearance of cartilaginous hypurals 1–2 and parhypural,followed by Hy3–5 at 6.08 mm NL.Cartilaginous Hy6 was visible by 9.58 mm SL in postflexion larvae.Six hypural bones were present from the postflexion to juvenile stage.Principal fin rays formed via intramembranous ossification at 6.32 mm NL,and segmentation was evident by 10.24 mm SL.Neural arch 1 appeared at 7.38 mm NL,preceding full haemal arch development.Uroneurals 1–2 and ural centra ossified by 9.58 mm SL,with Hy5 detached from U1 at 10.24 mm SL.Preural centra ossified before the arches.Epurals 1 and 2 were evident by 10.24 mm SL.Dorsal fin proximal radials developed anteriorly and distal radials posteriorly.Pectoral fin development initiated with an ossified cleithrum and the coracoscapular cartilage at 5.25 mm NL.By 10.24 mm SL,cartilaginous neural and haemal arches and spines were distinct.Uroneural 1 initially develops as cartilage.The formation of a pleurostyle aligns with clupeoid fish skeletal ontogeny.Dorsal and anal fin development follows a distinctive pattern,with variability in fin support development.Our results reveal accelerated caudal complex formation in E.punctifer and contribute new knowledge on the osteological characteristics of the genus Encrasicholina,and aid in understanding larval and juvenile ontogeny of marine teleosts.展开更多
Low-velocity impact tests are carried out to explore the energy absorption characteristics of bio-inspired lattices,mimicking the architecture of the marine sponge organism Euplectella aspergillum.These sea sponge-ins...Low-velocity impact tests are carried out to explore the energy absorption characteristics of bio-inspired lattices,mimicking the architecture of the marine sponge organism Euplectella aspergillum.These sea sponge-inspired lattice structures feature a square-grid 2D lattice with double diagonal bracings and are additively manufactured via digital light processing(DLP).The collapse strength and energy absorption capacity of sea sponge lattice structures are evaluated under various impact conditions and are compared to those of their constituent square-grid and double diagonal lattices.This study demonstrates that sea sponge lattices can achieve an 11-fold increase in energy absorption compared to the square-grid lattice,due to the stabilizing effect of the double diagonal bracings prompting the structure to collapse layer-bylayer under impact.By adjusting the thickness ratio in the sea sponge lattice,up to 76.7%increment in energy absorption is attained.It is also shown that sea-sponge lattices outperform well-established energy-absorbing materials of equal weight,such as hexagonal honeycombs,confirming their significant potential for impact mitigation.Additionally,this research highlights the enhancements in energy absorption achieved by adding a small amount(0.015 phr)of Multi-Walled Carbon Nanotubes(MWCNTs)to the photocurable resin,thus unlocking new possibilities for the design of innovative lightweight structures with multifunctional attributes.展开更多
Sandwich structures are widely favored for their lightweight,high strength and superior impact mitigation capabilities in blast mitigation and transportation safety applications.Their application in large-scale,high-e...Sandwich structures are widely favored for their lightweight,high strength and superior impact mitigation capabilities in blast mitigation and transportation safety applications.Their application in large-scale,high-energy rockfall protection remains limited due to their relatively low volumetric energy absorption efficiency and the complex fabrication processes of key energy-absorbing components.To address these limitations,this study proposes a novel sandwich structure incorporating mild steel tubes as core energy absorbers to efficiently mitigate highenergy rockfall impacts.A finite element model was developed in LS-DYNA to systematically investigate the deformation and energy absorption behaviors.Comprehensive parametric analyses were conducted to quantify the effects of key design variables,including tube wall thickness,tube spacing(number of tubes),and infill materials.The results demonstrate that increasing tube wall thickness significantly enhances ultimate energy absorption,with 12-mm-thick tubes absorbing 2.2 times more energy than 6-mm-thick tubes.Lateral constraints induced by adjacent tubes improve specific energy absorption per unit displacement by approximately 30%-45%.Furthermore,incorporating infill materials considerably enhances energy absorption,with aluminum foam infills achieving an 81%increase compared to empty tubes.Nevertheless,higher energy absorption capacity typically leads to greater peak impact forces,increasing the number of tubes offers a better balance between energy absorption and impact force,optimizing the structural performance.These findings provide valuable theoretical insights and practical guidelines for designing sandwich structures in civil and infrastructure engineering applications for effective rockfall protection.展开更多
Habitat loss driven by land-use change is a major factor shaping the dynamics of urban bird community structures.However,the potential mechanisms by which the spatial configuration and composition of blue-green infras...Habitat loss driven by land-use change is a major factor shaping the dynamics of urban bird community structures.However,the potential mechanisms by which the spatial configuration and composition of blue-green infrastructure,recognized as biodiversity hotspots in urban landscapes,influence urban bird beta diversity remain insufficiently understood.This study was conducted in the built-up area of Yinchuan,an internationally recognized wetland city in Northwest China.From December 2023 to June 2024,we systematically surveyed bird communities during both the breeding and wintering periods across 29 blue-green space mosaics.We quantified taxonomic,functional,and phylogenetic beta diversity,along with their turnover component and nestedness-resultant component,based on both pairwise beta diversity and multiple-site beta diversity.We further assessed the relative importance of landscape variables and spatial geographic distance in shaping beta diversity patterns and used hierarchical modeling of species communities(HMSC)to explore the responses of bird occurrence and functional traits to landscape variables.Our results revealed that species turnover was the dominant driver of taxonomic,functional,and phylogenetic beta diversity.Seasonal differences were observed in the effects of spatial geographic distance and landscape structure on beta diversity and its components,with landscape variables showing higher explanatory power than geographic isolation.In the breeding period,landscape diversity and waterbody area had positive effects on bird occurrence,whereas in the wintering period,most landscape features—except for landscape diversity—exerted neutral or negative influences.Regarding functional traits,we found that reproductive traits,flight ability,and foraging characteristics responded significantly to landscape structure,and that some small-bodied species active in aerial and canopy layers were more adaptable to habitat fragmentation.This study provides novel insights into the assembly processes and driving mechanisms of urban bird communities and offers scientific support for the notion that designing and maintaining blue-green infrastructure can contribute to urban biodiversity conservation.展开更多
Because of the developed surface of the Triply PeriodicMinimumSurface(TPMS)structures,polylactide(PLA)products with a TPMS structure are thought to be promising bio soluble implants with the potential for targeted dru...Because of the developed surface of the Triply PeriodicMinimumSurface(TPMS)structures,polylactide(PLA)products with a TPMS structure are thought to be promising bio soluble implants with the potential for targeted drug delivery.For implants,mechanical properties are key performance characteristics,so understanding the deformation and failure mechanisms is essential for selecting the appropriate implant structure.The deformation and fracture processes in PLA samples with different interior architectures have been studied through computer simulation and experimental research.Two TPMS topologies,the Schwarz Diamond and Gyroid architectures,were used for the sample construction by 3D printing.ANSYS software was utilized to simulate compressive deformation.It was found that under the same load,the vonMises stresses in the Gyroid structure are higher than those in the Schwartz Diamond structure,which was associated with the different orientations of the cells in the studied structures in relation to the direction of the loading axis.The deformation process occurs in the local regions of the studied TPMS structures.Maximum von Mises stresses were observed in the vertical parts of the structures oriented along the load direction.It was found that,unlike the Gyroid,the Schwartz Diamond structure contains a frame that forms unique stiffening ribs,which ensures the redistribution of the load under the vertical loading direction.An analysis of the mechanical characteristics of PLA samples with the Schwartz Diamond and Gyroid structures produced by the Fused Deposition Modeling(FDM)method was correlated with computer simulation.The Schwarz Diamond-type structure was shown to have a higher absorption energy than the Gyroid one.A study of the fracture in PLA samples with various cell sizes revealed a particular feature related to the samples’periodic surface topology and the 3D printing process.Scanning electron microscopic(SEM)studies of the samples deformed by compression showed thatwith an increase in the density of the samples,the failure mechanism changes from ductile to quasi-brittle due to the complex participation of both cell deformation and fiber deformation.展开更多
The testing of large structures is limited by high costs and long cycles, making scaling methods an attractive solution. However, the scaling process of elastic rings introduces complexities in multi-parameter geometr...The testing of large structures is limited by high costs and long cycles, making scaling methods an attractive solution. However, the scaling process of elastic rings introduces complexities in multi-parameter geometric distortions, leading to a diminution in the predictive accuracy of the distorted similitude. To address this challenge, this study formulates a novel set of scaling laws, tailored to account for the intricate geometric distortions associated with elastic rings. The proposed scaling laws are formulated based on the intrinsic deformation characteristics of elastic rings, rather than the traditional systemic governing equations. Numerical and experimental cases are conducted to assess the efficacy and precision of the proposed scaling laws, and the obtained results are compared with those achieved by traditional methods. The outcomes demonstrate that the scaling laws put forth by this study significantly enhance the predictive capabilities for deformations of elastic rings.展开更多
Fine-grained nuclear graphite is a key material in high-temperature gas-cooled reactors(HTGRs).During air ingress accidents,core graphite components undergo severe oxidation,threatening structural integrity.Therefore,...Fine-grained nuclear graphite is a key material in high-temperature gas-cooled reactors(HTGRs).During air ingress accidents,core graphite components undergo severe oxidation,threatening structural integrity.Therefore,understanding the oxidation behavior of nuclear graphite is essential for reactor safety.The influence of oxidation involves multiple factors,including temperature,sample size,oxidant,impurities,filler type and size,etc.The size of the filler particles plays a crucial role in this study.Five ultrafine-and superfine-grained nuclear graphite samples(5.9-34.4μm)are manufactured using identical raw materials and manufacturing processes.Isothermal oxidation tests conducted at 650℃-750℃ are used to study the oxidation behavior.Additionally,comprehensive characterization is performed to analyze the crystal structure,surface morphology,and nanoscale to microscale pore structure of the samples.Results indicate that oxidation behavior cannot be predicted solely based on filler grain size.Reactive site concentration,characterized by active surface area,dominates the chemical reaction kinetics,whereas pore tortuosity,quantified by the structural parameterΨ,plays a key role in regulating oxidant diffusion.These findings clarify the dual role of microstructure in oxidation mechanisms and establish a theoretical and experimental basis for the design of high-performance nuclear graphite capable of long-term service in high-temperature gas-cooled reactors.展开更多
Conformal truss-like lattice structures face significant manufacturability challenges in additive manufac-turing due to overhang angle limitations.To address this problem,we propose a novel angle-constrained optimizat...Conformal truss-like lattice structures face significant manufacturability challenges in additive manufac-turing due to overhang angle limitations.To address this problem,we propose a novel angle-constrained optimization method grounded in the global adjustment of nodal coordinates.First,a build direction is selected to minimize the number of violating struts.Then,an angular-constraint matrix is assembled from strut direction vectors,and analytical sensitivities with respect to nodal coordinates are derived to enable efficient constrained optimization under nonlinear angular inequality constraints.Numerical studies on two complex curved-surface lattices demonstrate that all overhang violations are eliminated while only minor changes are induced in global stiffness and strength.In particular,the maximum displacement of an ergonomic insole varies by only 2.87%after optimization.The results confirm the method’s versatility and engineering robustness,providing a practical approach for additive manufacturing-oriented lattice structure design.展开更多
In this study,the shell structure of olives in nature was modeled,and a high-porosity bionic olive body-centered cubic structure(BCCO)with reinforcement structures of circular support(BCCR)and triangular support(BCCT)...In this study,the shell structure of olives in nature was modeled,and a high-porosity bionic olive body-centered cubic structure(BCCO)with reinforcement structures of circular support(BCCR)and triangular support(BCCT)with excellent mechanical properties was designed and prepared using selective laser melting technology.The surface morphology,deformation behavior,and energy absorption of BCCO were compared with those of the equivalent uniform body-centered cubic structure(BCC)and analyzed through quasi-static compression experiments and finite element analysis.The olive-shaped structure showed optimal load resistance when the radius of curvature was equal to the edge length of the lattice structure,and outperformed with a larger curvature than with a smaller curvature.With the added support structure,the energy absorption of the BCCR increased by 144.44%compared with that of the conventional BCC structure.The newly designed olive bionic structure has considerable potential for applications in various fields,such as aerospace and medical devices.展开更多
Vacancy defects,as fundamental disruptions in metallic lattices,play an important role in shaping the mechanical and electronic properties of aluminum crystals.However,the influence of vacancy position under coupled t...Vacancy defects,as fundamental disruptions in metallic lattices,play an important role in shaping the mechanical and electronic properties of aluminum crystals.However,the influence of vacancy position under coupled thermomechanical fields remains insufficiently understood.In this study,transmission and scanning electron microscopy were employed to observe dislocation structures and grain boundary heterogeneities in processed aluminum alloys,suggesting stress concentrations and microstructural inhomogeneities associated with vacancy accumulation.To complement these observations,first-principles calculations and molecular dynamics simulations were conducted for seven single-vacancy configurations in face-centered cubic aluminum.The stress response,total energy,density of states(DOS),and differential charge density were examined under varying compressive strain(ε=0–0.1)and temperature(0–600 K).The results indicate that face-centered vacancies tend to reduce mechanical strength and perturb electronic states near the Fermi level,whereas corner and edge vacancies appear to have weaker effects.Elevated temperatures may partially restore electronic uniformity through thermal excitation.Overall,these findings suggest that vacancy position exerts a critical but position-dependent influence on coupled structure-property relationships,offering theoretical insights and preliminary experimental support for defect-engineered aluminum alloy design.展开更多
Abuse of chloramphenicol(CAP)could cause serious side effects to human health.Therefore,it is necessary to detect CAP residues in animal sourced food effectively.Here,the superiority(better stability,higher Apt-CAP lo...Abuse of chloramphenicol(CAP)could cause serious side effects to human health.Therefore,it is necessary to detect CAP residues in animal sourced food effectively.Here,the superiority(better stability,higher Apt-CAP loading efficiency,and higher CAP binding associated conformational change,etc.)of tetrahedral structure to double-chained structure for developing aptasensor was evaluated.Then,a self-assembled DNA tetrahedral structure-based electrochemical aptasensor targeting CAP was developed.Under the optimized conditions,the aptasensor exhibited high sensitivity toward CAP with a limit of detection(LOD)of 0.0676 ng/m L(linear range 0.19-387.76 ng/m L),and high selectivity against the structural analogs of CAP.Moreover,the recovery rate of CAP from spiked milk samples ranged from 100.57%to 101.69%,and only USD 1.34 is needed for detecting CAP in 1 sample.These results suggested the application potential of this aptasesor for detecting CAP in animal sourced foods.展开更多
4-Bromo-3-methylphenol(BMP)is an important chemical intermediate with wide applications in the fields of medicine and pesticides.The synthesis of BMP from m-cresol via bromination is easy to carry out on an industrial...4-Bromo-3-methylphenol(BMP)is an important chemical intermediate with wide applications in the fields of medicine and pesticides.The synthesis of BMP from m-cresol via bromination is easy to carry out on an industrial scale.However,due to the formation of regioisomeric impurities during bromination and the low melting point of BMP,the separation process is prone to the formation of oily substances,resulting in low yield and purity.In this work,a new cocrystallization engineering approach was proposed to separate and purify BMP.Through design of experiments,the cocrystallization process of BMP and triethylenediamine(DABCO)was optimized using a minimum-run resolution IV screening design combined with response surface methodology.In addition,the obtained 2BMP-DABCO powder was characterized by thermal analysis,powder X-ray diffraction,infrared spectroscopy,and scanning electron microscopy.Single crystals of 2BMP-DABCO were grown from acetone by slow evaporation,and detailed structural information was obtained through single-crystal X-ray diffraction.The self-assembly mechanism was further clarified by density functional theory calculations.This study provides a simple,robust,and scalable method for the production of BMP and offers a reference for the separation and purification of phenolic substances.展开更多
The emergence of precision electronic devices and wearable electronic products urgently requires high-performance multifunctional electromagnetic wave(EMW)absorbers to meet the applicability and versatility in various...The emergence of precision electronic devices and wearable electronic products urgently requires high-performance multifunctional electromagnetic wave(EMW)absorbers to meet the applicability and versatility in various applications.Herein,a dual-network(DN)gel was successfully prepared using acrylamide and sodium lignosulphonate as the basic units by simple chemical cross-linking and physical cross-linking methods.Specifically,the hydrogel forms two types of cross-linking networks through metal coordination and hydrogen bonding.Benefiting from the combined effects of dipole polarization and conductivity loss,the gel achieves an effective absorption bandwidth(EAB)of 6.74 GHz at a thickness of only 1.89 mm,demonstrating excellent EMW absorption performance.In addition,this unique structural configuration endows the EMW absorber with multifunctional features,such as remarkable tensile strength,good environmental compatibility,ultraviolet(UV)resistance,and excellent adhesion.Integrating multiple functional features into the EMW gels displays a broad application prospect in a variety of application scenarios.This research reveals the significance of DN structure design in the electromagnetic wave absorption(EWA)performance of gel-based materials,providing a substantial foundation for the multifunctional design of gel-based absorbers.展开更多
The Kumkol Basin,situated in the northern margin of the Qinghai-Xizang Plateau,provides a unique window into understanding the dynamic mechanisms driving the plateau’s northern expansion.However,its formation and tec...The Kumkol Basin,situated in the northern margin of the Qinghai-Xizang Plateau,provides a unique window into understanding the dynamic mechanisms driving the plateau’s northern expansion.However,its formation and tectonic evolution remain poorly understood due to limited geophysical data in this region.In this study,we computed cross-correlations for the TT components of station-pairs with high signal-to-noise ratios to extract Love wave waveforms and further performed Lovewave ambient noise tomography to image the upper crustal shear-wave velocity structure of the Kumkol basin down to 10 km depth.Our seismic velocity model reveals that the Kumkol Basin has a sedimentary thickness exceeding 8 km,with its center located near the Arka Mountain on the southern side.This suggests that the basin was likely formed as a foreland basin in response to the uplift of the Qiman Tagh Mountain to the north.Additionally,integrated with seismic reflection data,our seismic velocity model images a detachment fault at the basin basement depth.We inferred that the Kumkol Anticlinorium at the basin’s center have been produced by multiple thrust faults converging into this detachment fault at 8–10 km depth following the Early to Middle Miocene uplift of the Qiman Tagh Mountain.This structural configuration indicates pulsed basinward deformation since the late Miocene,likely reflecting a tectonic regime shift from extrusion to distributed shortening in the northern Qinghai-Xizang Plateau.Our findings provide a high-resolution velocity model of the Kumkol Basin,offering critical insights into its structural evolution and supporting future resource exploration in this underexplored region.展开更多
The structural changes in the CaO-SiO_(2)-Al_(2)O_(3)-MgO slag system with varying CaO contents were investigated through molecular dynamics(MD)simulations,and its effect on the dissolution behavior of alumina inclusi...The structural changes in the CaO-SiO_(2)-Al_(2)O_(3)-MgO slag system with varying CaO contents were investigated through molecular dynamics(MD)simulations,and its effect on the dissolution behavior of alumina inclusions was characterized by the Kullback-Leibler(KL)divergence.The slag structure analysis revealed that the[AlO]tetrahedral structure was the primary network structure in the slag.With increasing the CaO content,the non-bridge oxygen(NBO)content in the slag structure increases,and the bridge oxygen(BO)content decreases,thereby reducing the complexity of the slag network structure.Raman spectroscopy detection verifies the results of the MD simulations.The results indicated that the dissolution rate of alumina inclusions accelerates with increasing the CaO content in the slag,owing to the reduced complexity of the slag network structure and the enhanced interatomic interactions.The simulation results for the dissolution of alumina inclusions were consistent with theoretical calculations based on the slag inclusion capacity and the dimensionless dissolution rate of inclusions.Radial distribution function analysis demonstrated that the interaction between atoms in the slag system and alumina inclusions strengthens,increasing the dissolution rate of alumina inclusions.The[AlO_(6)]octahedral structure of the alumina inclusions is disrupted,forming BO structures,which in turn enhances the complexity of the slag network structure,slowing the dissolution rate of alumina inclusions.In contrast,the slag system with a higher CaO content has a relatively simpler network structure,promoting faster alumina inclusion dissolution.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No. 20843002)the Scientific and Technological Foundation of Shanxi Province of China (Grant No. 20080321065)
文摘Through different preparation technology, this paper reports that the needle coke is prepared with coal-tar pitch under the effect of magnetic field and ultrasonic cavitation. It studies the effect of physical disturbance on the structure of needle coke. The structure of needle coke is characterized by scanning electron microscope and x-ray diffractometer, and the influence mechanism is analysed. Results showed that the structure and property of needle coke could be effectively improved by magnetic field and ultrasonic cavitations, such as degree of order, degree of graphitization and crystallization. Comparatively speaking, the effect of magnetic field was greater. The graphitization degree of needle coke prepared under the effect of magnetic field is up to 45.35%.
基金finically supported by the Natural Science Foundation of China(31070591)Special National Forestry Public Welfare Industry Research(201104022)the support of Southwest Forestry University
文摘Pinus yunnanensis Franch. is an particular conifer tree species in Yunnan-Guizhou plateau in south- west China. The morphological and anatomical traits of needles are important to evaluate geographic variation and population dynamics of conifer species. Seedlings from seven populations of P. yunnanensis were analyzed, look- ing at 22 morphological and anatomical needle traits. The results showed that variations among and within popula- tions were significantly different for all traits and the variance components within populations were generally higher than that among populations in the most tested needle traits. The proportions of three-needle fascicle were significantly different among populations. The traits related to needle size in both morphology and anatomy were positive with latitude and negative with annual temperature and precipitation. Ratio indices, including mesophyllarea/vascular bundle area, mesophyll area/resin canals area, vascular bundle area/resin canals area and mesophyU area/（resin canals area and vascular bundle area）, were negatively correlated with elevation and positively corre- lated with the annual mean temperature, showing some fitness feature for the populations. Needle traits were more significantly correlated with longitude than with other four environmental factors. Needle length was significantly correlated with almost all environmental factors. First four principal components accounted for 81.596 % of the variation with eigenvalues 〉1; the differences among populations were mainly dependent on needle width, stomatal density, section areas of vascular bundle, total resin canals, and mesophyll, as well as area ratio traits. Seven populations were divided into three categories by Euclidean distance. Variations in needle traits among the populations have shown systematic microevolution in terms of geographic impact on P. yunnanensis. This study would provide empirical data to characterize adaptation and genetic variation of P. yunnanensis, which would be helpful for management of genetic resources and reason- able utilization of them in future.
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.
基金Supported by the Science and Technology Cooperation and Exchange special project of Cooperation of Shanxi Province(202404041101014)the Fundamental Research Program of Shanxi Province(202403021212333)+3 种基金the Joint Funds of the National Natural Science Foundation of China(U24A20555)the Lvliang Key R&D of University-Local Cooperation(2023XDHZ10)the Initiation Fund for Doctoral Research of Taiyuan University of Science and Technology(20242026)the Outstanding Doctor Funding Award of Shanxi Province(20242080).
文摘To elucidate the effect of calcite-regulated activated carbon(AC)structure on low-temperature denitrification performance of SCR catalysts,this work prepared a series of Mn-Ce/De-AC-xCaCO_(3)(x is the calcite content in coal)catalysts were prepared by the incipient wetness impregnation method,followed by acid washing to remove calcium-containing minerals.Comprehensive characterization and low-temperature denitrification tests revealed that calcite-induced structural modulation of coal-derived AC significantly enhances catalytic activity.Specifically,NO conversion increased from 88.3%of Mn-Ce/De-AC to 91.7%of Mn-Ce/De-AC-1CaCO_(3)(210℃).The improved SCR denitrification activity results from the enhancement of physicochemical properties including higher Mn^(4+)content and Ce^(4+)/Ce^(3+)ratio,an abundance of chemisorbed oxygen and acidic sites,which could strengthen the SCR reaction pathways(richer NH_(3)activated species and bidentate nitrate active species).Therefore,NO removal is enhanced.
基金Supported by the National Key Research and Development Program of Traditional Chinese Medicine Modernization Project,China(No.2023YFC3504000)the Science and Technology Development Project of Jilin Province,China(No.20240404043ZP)the Science and Technology Innovation Cooperation Project of Changchun Science and Technology Bureau and Chinese Academy of Sciences,China(No.23SH14)。
文摘In this study,a novel polysaccharide GPA-G 2-H was derived from ginseng.Furthermore,the coherent study of its structural characteristics,fermented characteristics in vitro,as well as antioxidant mechanism of fermented product FGPA-G 2-H on Aβ25-35-induced PC 12 cells were explored.The structure of GPA-G 2-H was determined by means of zeta potential analysis,FTIR,HPLC,XRD,GC-MS and NMR.The backbone of GPA-G 2-H was mainly composed of→4)-α-D-Glcp-(1→with branches substituted at O-3.Notably,GPA-G 2-H was degraded by intestinal microbiota in vitro with total sugar content and pH value decreasing,and short-chain fatty acids(SCFAs)increasing.Moreover,GPA-G 2-H significantly promoted the proliferation of Lactobacillus,Muribaculaceae and Weissella,thereby making positive alterations in intestinal microbiota composition.Additionally,FGPA-G 2-H activated the Nrf 2/HO-1 signaling pathway,enhanced HO-1,NQO 1,SOD and GSH-Px,while inhabited Keap 1,MDA and LDH,which alleviated Aβ-induced oxidative stress in PC 12 cells.These provide a solid theoretical basis for the further development of ginseng polysaccharides as functional food and antioxidant drugs.
文摘Anchovies are key forage species in coastal and pelagic food webs,playing crucial ecological and commercial roles in marine ecosystems.Encrasicholina punctifer is a commercially and ecologically important species,yet little is known about its osteological development characteristics.Understanding these ontogenetic patterns is essential for explaining phylogenetic relationships within Clupeiformes,informing larval identification in ichthyoplankton surveys,and enhancing aquaculture practices.This study describes the ontogenetic characteristics of the appendicular and median skeletons and fin supports in E.punctifer larvae and juveniles,providing quantitative ontogenetic timelines to address gaps in engraulid developmental biology and contribute to teleost ontogeny research.Larval and juvenile specimens of E.punctifer;size range:3.00-34.56 mm standard length(SL)and notochord length(NL)collected from the Philippine Sea were processed using the standard Alizarin red and Alcian blue clearing-and-staining technique to differentiate ossified and cartilaginous elements.Specimens were examined under a stereo microscope and imaged with an HTC1600ISP digital camera for detailed morphological analysis of skeletal structures.Caudal complex development was evident by 5.55 mm NL,with the initial appearance of cartilaginous hypurals 1–2 and parhypural,followed by Hy3–5 at 6.08 mm NL.Cartilaginous Hy6 was visible by 9.58 mm SL in postflexion larvae.Six hypural bones were present from the postflexion to juvenile stage.Principal fin rays formed via intramembranous ossification at 6.32 mm NL,and segmentation was evident by 10.24 mm SL.Neural arch 1 appeared at 7.38 mm NL,preceding full haemal arch development.Uroneurals 1–2 and ural centra ossified by 9.58 mm SL,with Hy5 detached from U1 at 10.24 mm SL.Preural centra ossified before the arches.Epurals 1 and 2 were evident by 10.24 mm SL.Dorsal fin proximal radials developed anteriorly and distal radials posteriorly.Pectoral fin development initiated with an ossified cleithrum and the coracoscapular cartilage at 5.25 mm NL.By 10.24 mm SL,cartilaginous neural and haemal arches and spines were distinct.Uroneural 1 initially develops as cartilage.The formation of a pleurostyle aligns with clupeoid fish skeletal ontogeny.Dorsal and anal fin development follows a distinctive pattern,with variability in fin support development.Our results reveal accelerated caudal complex formation in E.punctifer and contribute new knowledge on the osteological characteristics of the genus Encrasicholina,and aid in understanding larval and juvenile ontogeny of marine teleosts.
基金supported by the Khalifa University of Science and Technology internal grants(Nos.2021-CIRA-109,2020-CIRA-007,and 2020-CIRA-024).
文摘Low-velocity impact tests are carried out to explore the energy absorption characteristics of bio-inspired lattices,mimicking the architecture of the marine sponge organism Euplectella aspergillum.These sea sponge-inspired lattice structures feature a square-grid 2D lattice with double diagonal bracings and are additively manufactured via digital light processing(DLP).The collapse strength and energy absorption capacity of sea sponge lattice structures are evaluated under various impact conditions and are compared to those of their constituent square-grid and double diagonal lattices.This study demonstrates that sea sponge lattices can achieve an 11-fold increase in energy absorption compared to the square-grid lattice,due to the stabilizing effect of the double diagonal bracings prompting the structure to collapse layer-bylayer under impact.By adjusting the thickness ratio in the sea sponge lattice,up to 76.7%increment in energy absorption is attained.It is also shown that sea-sponge lattices outperform well-established energy-absorbing materials of equal weight,such as hexagonal honeycombs,confirming their significant potential for impact mitigation.Additionally,this research highlights the enhancements in energy absorption achieved by adding a small amount(0.015 phr)of Multi-Walled Carbon Nanotubes(MWCNTs)to the photocurable resin,thus unlocking new possibilities for the design of innovative lightweight structures with multifunctional attributes.
基金supported by the National Key R&D Program of China(Grant No.2019YFC1509703)the Tianjin Science and Technology Program Project(Grant No.23YFYSHZ00130)。
文摘Sandwich structures are widely favored for their lightweight,high strength and superior impact mitigation capabilities in blast mitigation and transportation safety applications.Their application in large-scale,high-energy rockfall protection remains limited due to their relatively low volumetric energy absorption efficiency and the complex fabrication processes of key energy-absorbing components.To address these limitations,this study proposes a novel sandwich structure incorporating mild steel tubes as core energy absorbers to efficiently mitigate highenergy rockfall impacts.A finite element model was developed in LS-DYNA to systematically investigate the deformation and energy absorption behaviors.Comprehensive parametric analyses were conducted to quantify the effects of key design variables,including tube wall thickness,tube spacing(number of tubes),and infill materials.The results demonstrate that increasing tube wall thickness significantly enhances ultimate energy absorption,with 12-mm-thick tubes absorbing 2.2 times more energy than 6-mm-thick tubes.Lateral constraints induced by adjacent tubes improve specific energy absorption per unit displacement by approximately 30%-45%.Furthermore,incorporating infill materials considerably enhances energy absorption,with aluminum foam infills achieving an 81%increase compared to empty tubes.Nevertheless,higher energy absorption capacity typically leads to greater peak impact forces,increasing the number of tubes offers a better balance between energy absorption and impact force,optimizing the structural performance.These findings provide valuable theoretical insights and practical guidelines for designing sandwich structures in civil and infrastructure engineering applications for effective rockfall protection.
基金supported by the National Natural Science Foundation of China(32401409)the Central Government’s Special Fund for National Key Protected Wildlife Conservation Projects in Yinchuan City(HXCG-ZC2023148,XZ-2024-16)。
文摘Habitat loss driven by land-use change is a major factor shaping the dynamics of urban bird community structures.However,the potential mechanisms by which the spatial configuration and composition of blue-green infrastructure,recognized as biodiversity hotspots in urban landscapes,influence urban bird beta diversity remain insufficiently understood.This study was conducted in the built-up area of Yinchuan,an internationally recognized wetland city in Northwest China.From December 2023 to June 2024,we systematically surveyed bird communities during both the breeding and wintering periods across 29 blue-green space mosaics.We quantified taxonomic,functional,and phylogenetic beta diversity,along with their turnover component and nestedness-resultant component,based on both pairwise beta diversity and multiple-site beta diversity.We further assessed the relative importance of landscape variables and spatial geographic distance in shaping beta diversity patterns and used hierarchical modeling of species communities(HMSC)to explore the responses of bird occurrence and functional traits to landscape variables.Our results revealed that species turnover was the dominant driver of taxonomic,functional,and phylogenetic beta diversity.Seasonal differences were observed in the effects of spatial geographic distance and landscape structure on beta diversity and its components,with landscape variables showing higher explanatory power than geographic isolation.In the breeding period,landscape diversity and waterbody area had positive effects on bird occurrence,whereas in the wintering period,most landscape features—except for landscape diversity—exerted neutral or negative influences.Regarding functional traits,we found that reproductive traits,flight ability,and foraging characteristics responded significantly to landscape structure,and that some small-bodied species active in aerial and canopy layers were more adaptable to habitat fragmentation.This study provides novel insights into the assembly processes and driving mechanisms of urban bird communities and offers scientific support for the notion that designing and maintaining blue-green infrastructure can contribute to urban biodiversity conservation.
文摘Because of the developed surface of the Triply PeriodicMinimumSurface(TPMS)structures,polylactide(PLA)products with a TPMS structure are thought to be promising bio soluble implants with the potential for targeted drug delivery.For implants,mechanical properties are key performance characteristics,so understanding the deformation and failure mechanisms is essential for selecting the appropriate implant structure.The deformation and fracture processes in PLA samples with different interior architectures have been studied through computer simulation and experimental research.Two TPMS topologies,the Schwarz Diamond and Gyroid architectures,were used for the sample construction by 3D printing.ANSYS software was utilized to simulate compressive deformation.It was found that under the same load,the vonMises stresses in the Gyroid structure are higher than those in the Schwartz Diamond structure,which was associated with the different orientations of the cells in the studied structures in relation to the direction of the loading axis.The deformation process occurs in the local regions of the studied TPMS structures.Maximum von Mises stresses were observed in the vertical parts of the structures oriented along the load direction.It was found that,unlike the Gyroid,the Schwartz Diamond structure contains a frame that forms unique stiffening ribs,which ensures the redistribution of the load under the vertical loading direction.An analysis of the mechanical characteristics of PLA samples with the Schwartz Diamond and Gyroid structures produced by the Fused Deposition Modeling(FDM)method was correlated with computer simulation.The Schwarz Diamond-type structure was shown to have a higher absorption energy than the Gyroid one.A study of the fracture in PLA samples with various cell sizes revealed a particular feature related to the samples’periodic surface topology and the 3D printing process.Scanning electron microscopic(SEM)studies of the samples deformed by compression showed thatwith an increase in the density of the samples,the failure mechanism changes from ductile to quasi-brittle due to the complex participation of both cell deformation and fiber deformation.
基金Project supported by the National Natural Science Foundation of China(Nos.52405095,12272089,and 92360305)the Guangdong Basic and Applied Basic Research Foundation of China(No.2023A1515110557)+4 种基金the Natural Science Foundation of Liaoning Province of China(No.2023-BSBA-102)the Open Fund of National Key Laboratory of Particle Transport and Separation Technology of China(No.WZKF-2024-6)the Open Project of Guangxi Key Laboratory of Automobile Components and Vehicle Technology of China(Nos.2024GKLACVTKF07 and 2024GKLACVTKF06)the Basic Research Projects of Liaoning Provincial Department of Education of China(No.JYTQN2023162)the Fundamental Research Funds for the Central Universities of China(No.N2403022)。
文摘The testing of large structures is limited by high costs and long cycles, making scaling methods an attractive solution. However, the scaling process of elastic rings introduces complexities in multi-parameter geometric distortions, leading to a diminution in the predictive accuracy of the distorted similitude. To address this challenge, this study formulates a novel set of scaling laws, tailored to account for the intricate geometric distortions associated with elastic rings. The proposed scaling laws are formulated based on the intrinsic deformation characteristics of elastic rings, rather than the traditional systemic governing equations. Numerical and experimental cases are conducted to assess the efficacy and precision of the proposed scaling laws, and the obtained results are compared with those achieved by traditional methods. The outcomes demonstrate that the scaling laws put forth by this study significantly enhance the predictive capabilities for deformations of elastic rings.
基金supported by the National Key Research and Development Program of China(2024YFA1612900)the National Natural Science Foundation of China(Grant No.52103365 and No.12375270)the Guangdong Innovative and Entrepreneurial Research Team Program,China(Grant No.2021ZT09L227).
文摘Fine-grained nuclear graphite is a key material in high-temperature gas-cooled reactors(HTGRs).During air ingress accidents,core graphite components undergo severe oxidation,threatening structural integrity.Therefore,understanding the oxidation behavior of nuclear graphite is essential for reactor safety.The influence of oxidation involves multiple factors,including temperature,sample size,oxidant,impurities,filler type and size,etc.The size of the filler particles plays a crucial role in this study.Five ultrafine-and superfine-grained nuclear graphite samples(5.9-34.4μm)are manufactured using identical raw materials and manufacturing processes.Isothermal oxidation tests conducted at 650℃-750℃ are used to study the oxidation behavior.Additionally,comprehensive characterization is performed to analyze the crystal structure,surface morphology,and nanoscale to microscale pore structure of the samples.Results indicate that oxidation behavior cannot be predicted solely based on filler grain size.Reactive site concentration,characterized by active surface area,dominates the chemical reaction kinetics,whereas pore tortuosity,quantified by the structural parameterΨ,plays a key role in regulating oxidant diffusion.These findings clarify the dual role of microstructure in oxidation mechanisms and establish a theoretical and experimental basis for the design of high-performance nuclear graphite capable of long-term service in high-temperature gas-cooled reactors.
基金supported by the National Natural Science Foundation of China(Grant Nos.12432005 and 12472116)the Fundamental Research Funds for the Central Universities(DUTZD25240).
文摘Conformal truss-like lattice structures face significant manufacturability challenges in additive manufac-turing due to overhang angle limitations.To address this problem,we propose a novel angle-constrained optimization method grounded in the global adjustment of nodal coordinates.First,a build direction is selected to minimize the number of violating struts.Then,an angular-constraint matrix is assembled from strut direction vectors,and analytical sensitivities with respect to nodal coordinates are derived to enable efficient constrained optimization under nonlinear angular inequality constraints.Numerical studies on two complex curved-surface lattices demonstrate that all overhang violations are eliminated while only minor changes are induced in global stiffness and strength.In particular,the maximum displacement of an ergonomic insole varies by only 2.87%after optimization.The results confirm the method’s versatility and engineering robustness,providing a practical approach for additive manufacturing-oriented lattice structure design.
基金Supported by Key Technologies Research and Development Program of China(Grant No.2022YFC2406004).
文摘In this study,the shell structure of olives in nature was modeled,and a high-porosity bionic olive body-centered cubic structure(BCCO)with reinforcement structures of circular support(BCCR)and triangular support(BCCT)with excellent mechanical properties was designed and prepared using selective laser melting technology.The surface morphology,deformation behavior,and energy absorption of BCCO were compared with those of the equivalent uniform body-centered cubic structure(BCC)and analyzed through quasi-static compression experiments and finite element analysis.The olive-shaped structure showed optimal load resistance when the radius of curvature was equal to the edge length of the lattice structure,and outperformed with a larger curvature than with a smaller curvature.With the added support structure,the energy absorption of the BCCR increased by 144.44%compared with that of the conventional BCC structure.The newly designed olive bionic structure has considerable potential for applications in various fields,such as aerospace and medical devices.
基金supported by the Research Project on Strengthening the Construction of an Important Ecological Security Barrier in Northern China by Higher Education Institutions in the Inner Mongolia Autonomous Region(STAQZX202313)the Inner Mongolia Autonomous Region Education Science‘14th Five-Year Plan’2024 Annual Research Project(NGJGH2024635).
文摘Vacancy defects,as fundamental disruptions in metallic lattices,play an important role in shaping the mechanical and electronic properties of aluminum crystals.However,the influence of vacancy position under coupled thermomechanical fields remains insufficiently understood.In this study,transmission and scanning electron microscopy were employed to observe dislocation structures and grain boundary heterogeneities in processed aluminum alloys,suggesting stress concentrations and microstructural inhomogeneities associated with vacancy accumulation.To complement these observations,first-principles calculations and molecular dynamics simulations were conducted for seven single-vacancy configurations in face-centered cubic aluminum.The stress response,total energy,density of states(DOS),and differential charge density were examined under varying compressive strain(ε=0–0.1)and temperature(0–600 K).The results indicate that face-centered vacancies tend to reduce mechanical strength and perturb electronic states near the Fermi level,whereas corner and edge vacancies appear to have weaker effects.Elevated temperatures may partially restore electronic uniformity through thermal excitation.Overall,these findings suggest that vacancy position exerts a critical but position-dependent influence on coupled structure-property relationships,offering theoretical insights and preliminary experimental support for defect-engineered aluminum alloy design.
基金supported by the National Nature Science Foundation of China(82174531)the Medicine and Health Science Technology Development Project of Shandong Province,China(202212060626).
文摘Abuse of chloramphenicol(CAP)could cause serious side effects to human health.Therefore,it is necessary to detect CAP residues in animal sourced food effectively.Here,the superiority(better stability,higher Apt-CAP loading efficiency,and higher CAP binding associated conformational change,etc.)of tetrahedral structure to double-chained structure for developing aptasensor was evaluated.Then,a self-assembled DNA tetrahedral structure-based electrochemical aptasensor targeting CAP was developed.Under the optimized conditions,the aptasensor exhibited high sensitivity toward CAP with a limit of detection(LOD)of 0.0676 ng/m L(linear range 0.19-387.76 ng/m L),and high selectivity against the structural analogs of CAP.Moreover,the recovery rate of CAP from spiked milk samples ranged from 100.57%to 101.69%,and only USD 1.34 is needed for detecting CAP in 1 sample.These results suggested the application potential of this aptasesor for detecting CAP in animal sourced foods.
基金supported by the National Natural Science Foundation of China(22177011(R.Z.Qiao),21977012(R.Z.Qiao),and 21572018(C.Li))the National High-Level Hospital Clinical Research Funding(2023-NHLHCRF-YXHZ-ZRMS-02)the Joint Project of BRCBC(Biomedical Translational Engineering Research Center of BUCT-CJFH)(XK2020-06).
文摘4-Bromo-3-methylphenol(BMP)is an important chemical intermediate with wide applications in the fields of medicine and pesticides.The synthesis of BMP from m-cresol via bromination is easy to carry out on an industrial scale.However,due to the formation of regioisomeric impurities during bromination and the low melting point of BMP,the separation process is prone to the formation of oily substances,resulting in low yield and purity.In this work,a new cocrystallization engineering approach was proposed to separate and purify BMP.Through design of experiments,the cocrystallization process of BMP and triethylenediamine(DABCO)was optimized using a minimum-run resolution IV screening design combined with response surface methodology.In addition,the obtained 2BMP-DABCO powder was characterized by thermal analysis,powder X-ray diffraction,infrared spectroscopy,and scanning electron microscopy.Single crystals of 2BMP-DABCO were grown from acetone by slow evaporation,and detailed structural information was obtained through single-crystal X-ray diffraction.The self-assembly mechanism was further clarified by density functional theory calculations.This study provides a simple,robust,and scalable method for the production of BMP and offers a reference for the separation and purification of phenolic substances.
基金supported by the National Natural Science Foundation of China(Nos.52231007,51872238,52074227,and 21806129)the Fundamental Research Funds for the Central Universities(Nos.3102018zy045,3102019AX11,and 5000220455)the Natural Science Basic Research Plan in Shaanxi Province of China(Nos.2017JQ5116 and 2020JM-118).
文摘The emergence of precision electronic devices and wearable electronic products urgently requires high-performance multifunctional electromagnetic wave(EMW)absorbers to meet the applicability and versatility in various applications.Herein,a dual-network(DN)gel was successfully prepared using acrylamide and sodium lignosulphonate as the basic units by simple chemical cross-linking and physical cross-linking methods.Specifically,the hydrogel forms two types of cross-linking networks through metal coordination and hydrogen bonding.Benefiting from the combined effects of dipole polarization and conductivity loss,the gel achieves an effective absorption bandwidth(EAB)of 6.74 GHz at a thickness of only 1.89 mm,demonstrating excellent EMW absorption performance.In addition,this unique structural configuration endows the EMW absorber with multifunctional features,such as remarkable tensile strength,good environmental compatibility,ultraviolet(UV)resistance,and excellent adhesion.Integrating multiple functional features into the EMW gels displays a broad application prospect in a variety of application scenarios.This research reveals the significance of DN structure design in the electromagnetic wave absorption(EWA)performance of gel-based materials,providing a substantial foundation for the multifunctional design of gel-based absorbers.
基金funded by the National Natural Science Foundation of China(No.42274066),the Second Qinghai-Xizang Plateau Scientific Expedition and Research Program(STEP)(No.2019Q ZKK0701).
文摘The Kumkol Basin,situated in the northern margin of the Qinghai-Xizang Plateau,provides a unique window into understanding the dynamic mechanisms driving the plateau’s northern expansion.However,its formation and tectonic evolution remain poorly understood due to limited geophysical data in this region.In this study,we computed cross-correlations for the TT components of station-pairs with high signal-to-noise ratios to extract Love wave waveforms and further performed Lovewave ambient noise tomography to image the upper crustal shear-wave velocity structure of the Kumkol basin down to 10 km depth.Our seismic velocity model reveals that the Kumkol Basin has a sedimentary thickness exceeding 8 km,with its center located near the Arka Mountain on the southern side.This suggests that the basin was likely formed as a foreland basin in response to the uplift of the Qiman Tagh Mountain to the north.Additionally,integrated with seismic reflection data,our seismic velocity model images a detachment fault at the basin basement depth.We inferred that the Kumkol Anticlinorium at the basin’s center have been produced by multiple thrust faults converging into this detachment fault at 8–10 km depth following the Early to Middle Miocene uplift of the Qiman Tagh Mountain.This structural configuration indicates pulsed basinward deformation since the late Miocene,likely reflecting a tectonic regime shift from extrusion to distributed shortening in the northern Qinghai-Xizang Plateau.Our findings provide a high-resolution velocity model of the Kumkol Basin,offering critical insights into its structural evolution and supporting future resource exploration in this underexplored region.
基金supported by Special Funding Projects for Local Science and Technology Development guided by the Central Committee(No.YDZJSX2022C028)the Fundamental Research Program of Shanxi Province(Nos.20210302123218 and 202203021211187)+4 种基金Innovation and Entrepreneurship Training Program for College Students in Shanxi Province(202210109006)the National Natural Science Foundation(52474367)the Key Research and Development for University-Local Government Collaboration of Lvliang City(2024XDHZ01)the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi(2025Q022)the Foundation of State Key Laboratory of Advanced Metallurgy,USTB(K22-10).
文摘The structural changes in the CaO-SiO_(2)-Al_(2)O_(3)-MgO slag system with varying CaO contents were investigated through molecular dynamics(MD)simulations,and its effect on the dissolution behavior of alumina inclusions was characterized by the Kullback-Leibler(KL)divergence.The slag structure analysis revealed that the[AlO]tetrahedral structure was the primary network structure in the slag.With increasing the CaO content,the non-bridge oxygen(NBO)content in the slag structure increases,and the bridge oxygen(BO)content decreases,thereby reducing the complexity of the slag network structure.Raman spectroscopy detection verifies the results of the MD simulations.The results indicated that the dissolution rate of alumina inclusions accelerates with increasing the CaO content in the slag,owing to the reduced complexity of the slag network structure and the enhanced interatomic interactions.The simulation results for the dissolution of alumina inclusions were consistent with theoretical calculations based on the slag inclusion capacity and the dimensionless dissolution rate of inclusions.Radial distribution function analysis demonstrated that the interaction between atoms in the slag system and alumina inclusions strengthens,increasing the dissolution rate of alumina inclusions.The[AlO_(6)]octahedral structure of the alumina inclusions is disrupted,forming BO structures,which in turn enhances the complexity of the slag network structure,slowing the dissolution rate of alumina inclusions.In contrast,the slag system with a higher CaO content has a relatively simpler network structure,promoting faster alumina inclusion dissolution.
