Zinc oxide(ZnO)serves as a crucial functional semiconductor with a wide direct bandgap of approximately 3.37 eV.Solvothermal reaction is commonly used in the synthesis of ZnO micro/nanostructures,given its low cost,si...Zinc oxide(ZnO)serves as a crucial functional semiconductor with a wide direct bandgap of approximately 3.37 eV.Solvothermal reaction is commonly used in the synthesis of ZnO micro/nanostructures,given its low cost,simplicity,and easy implementation.Moreover,ZnO morphology engineering has become desirable through the alteration of minor conditions in the reaction process,particularly at room temperature.In this work,ZnO micro/nanostructures were synthesized in a solution by varying the amounts of the ammonia added at low temperatures(including room temperature).The formation of Zn^(2+)complexes by ammonia in the precursor regulated the reaction rate of the morphology engineering of ZnO,which resulted in various structures,such as nanoparticles,nanosheets,microflowers,and single crystals.Finally,the obtained ZnO was used in the optoelectronic application of ultraviolet detectors.展开更多
Multicomponent Gd_(1−x)Sm_(x)Ba_(0.5)Sr_(0.5)CoCuO_(5+δ)double perovskites are optimized for application in terms of chemical composi-tion and morphology for the use as oxygen electrodes in solid oxide cells.Structur...Multicomponent Gd_(1−x)Sm_(x)Ba_(0.5)Sr_(0.5)CoCuO_(5+δ)double perovskites are optimized for application in terms of chemical composi-tion and morphology for the use as oxygen electrodes in solid oxide cells.Structural studies of other physicochemical properties are con-ducted on a series of materials obtained by the sol-gel method with different ratios of Gd and Sm cations.It is documented that changing the x value,and the resulting adjustment of the average ionic radius,have a significant impact on the crystal structure,stability,as well as on the total conductivity and thermomechanical properties of the materials,with the best results obtained for the Gd_(0.75)Sm_(0.2)5Ba_(0.5)Sr_(0.5)CoCuO_(5+δ)composition.Oxygen electrodes are prepared using the selected compound,allowing to obtain low polarization resistance values,such as 0.086Ω·cm^(2)at 800℃.Systematic studies of electrocatalytic activity are conducted using La_(0.8)Sr_(0.2)Ga_(0.8)Mg_(_(0.2))O_(3−δ)as the electrolyte for all electrodes,and Ce_(0.8)Gd_(0.2)O_(2−δ)electrolyte for the best performing Gd_(0.75)Sm_(0.2)5Ba_(0.5)Sr_(0.5)CoCuO_(5+δ)electrodes.The electrochemical data are analyzed using the distribution of relaxation times method.Also,the influence of the preparation method of the electrode material is in-ve`stigated using the electrospinning technique.Finally,the performance of the Gd_(0.75)Sm_(0.2)5Ba_(0.5)Sr_(0.5)CoCuO_(5+δ)electrodes is tested in a Ni-YSZ(yttria-stabilized zirconia)anode-supported cell with a Ce_(0.8)Gd_(0.2)O_(2−δ)buffer layer,in the fuel cell and electrolyzer operating modes.With the electrospun electrode,a power density of 462 mW·cm^(−2)is obtained at 700℃,with a current density of ca.0.2 A·cm^(−2)at 1.3 V for the electrolysis at the same temperature,indicating better performance compared to the sol-gel-based electrode.展开更多
Morphological alterations in dendritic spines have been linked to changes in functional communication between neurons that affect learning and memory.Kinesin-4 KIF21A helps organize the microtubule-actin network at th...Morphological alterations in dendritic spines have been linked to changes in functional communication between neurons that affect learning and memory.Kinesin-4 KIF21A helps organize the microtubule-actin network at the cell cortex by interacting with KANK1;however,whether KIF21A modulates dendritic structure and function in neurons remains unknown.In this study,we found that KIF21A was distributed in a subset of dendritic spines,and that these KIF21A-positive spines were larger and more structurally plastic than KIF21A-negative spines.Furthermore,the interaction between KIF21A and KANK1 was found to be critical for dendritic spine morphogenesis and synaptic plasticity.Knockdown of either KIF21A or KANK1 inhibited dendritic spine morphogenesis and dendritic branching,and these deficits were fully rescued by coexpressing full-length KIF21A or KANK1,but not by proteins with mutations disrupting direct binding between KIF21A and KANK1 or binding between KANK1 and talin1.Knocking down KIF21A in the hippocampus of rats inhibited the amplitudes of long-term potentiation induced by high-frequency stimulation and negatively impacted the animals’cognitive abilities.Taken together,our findings demonstrate the function of KIF21A in modulating spine morphology and provide insight into its role in synaptic function.展开更多
Introduction: the left atrial appendage, a dormant embryonic vestige, would play a major role in cardiac hemodynamic changes, volume homeostasis and thrombi formation. It, therefore constitutes a therapeutic target. I...Introduction: the left atrial appendage, a dormant embryonic vestige, would play a major role in cardiac hemodynamic changes, volume homeostasis and thrombi formation. It, therefore constitutes a therapeutic target. Its morphology is extremely variable. Objective: it consisted on determining the morphological variations of the left auricle as well as their interest in the prevention of thrombi in the Senegalese. Material and Method: This study was conducted by dissecting 36 fresh hearts from Senegalese anatomical subjects with a sampling of the left atrial appendage, including specimens with normal morphological appearance. Their morphology was studied using the fresh and frozen plaster molding method. The data obtained were analyzed statistically. Results: the average age of the subjects was 33 years, with a sex ratio of 1.06, the cauliflower shape was dominant with 57% of cases and the cactus shape (4%) was less frequent. The cauliflower shape presented a clear angulation compared to the others without statistically significant differences according to age. Conclusion: This work showed a great morphological variability of the left atrial appendage. It can provide an update on the specificity of Senegalese. Taking these variations into account is important in the safe management of hemodynamic conditions and the improvement of the management of recurrent strokes.展开更多
The preferential oxidation of CO(CO-PROX)reaction is a cost-effective method for eliminating trace amounts of CO from the fuel H2.Pt-based catalysts have been extensively studied for COPROX,with their activity influen...The preferential oxidation of CO(CO-PROX)reaction is a cost-effective method for eliminating trace amounts of CO from the fuel H2.Pt-based catalysts have been extensively studied for COPROX,with their activity influenced by the morphology of the support.Hydrothermal synthesis was employed to produce different morphologies ofγ-Al_(2)O_(3):flower-likeγ-Al_(2)O_(3)(f)exposing(110)crystal faces,sheet-likeγ-Al_(2)O_(3)(s)revealing(100)crystal faces,and rod-likeγ-Al_(2)O_(3)(r)displaying(111)crystal faces,followed by loading PtCo nanoparticles.The exposed crystal faces of the support impact the alloying degree of the PtCo nanoparticles,and an increase in the alloying degree correlates with enhanced catalyst reactivity.Pt_(3)Co intermetallic compounds were identified onγ-Al_(2)O_(3)(f)exposing(110)crystal faces,and PtCo/γ-Al_(2)O_(3)(f)showed high catalytic activity in the CO-PROX reaction,achieving 100%CO conversion across a broad temperature range of 50−225°C.In contrast,only partial alloying of PtCo was observed onγ-Al_(2)O_(3)(s).Furthermore,no alloying between Pt and Co occurred in PtCo/γ-Al_(2)O_(3)(r),resulting in a reaction rate at 50°C that was merely 11%of that of PtCo/γ-Al_(2)O_(3)(f).The formation of Pt3Co intermetallic compounds led to a more oxidized state of Pt,which significantly diminished the adsorption of CO on Pt and augmented the active oxygen species,thereby facilitating the selective oxidation of CO.展开更多
Harrat Lunayyir,a volcanic field in western Saudi Arabia,exhibits diverse geomorphological and topographical features shaped by volcanic,tectonic,and climatic processes.This study integrates field observations,remote ...Harrat Lunayyir,a volcanic field in western Saudi Arabia,exhibits diverse geomorphological and topographical features shaped by volcanic,tectonic,and climatic processes.This study integrates field observations,remote sensing,and GIS analysis to investigate the spatial distribution and relationships between volcanic landforms,lava flows,and topographical variation result obtained is a morphological classification of the cinder cones of Harrat Lunayyir,which can be sub-divided into four types:tephra rings,horseshoe-shaped volcanoes,multiple volcanoes and volcanoes without craters.All of these are monogenetic volcanoes,unlike central volcanoes(stratovolcanoes)which live for tens or hundreds of thousands of years and erupt numerous times.In Harrat Lunayyir,there is a clear dominance of arched horseshoe-shaped volcanoes(58)over ring-shaped cinder cones(10),A1_symmetric cones(circular,uniform cinder cones with a single crater)(32),A2_asymmetric cones(elongated,irregular cones and may feature one or more craters)(8),volcanoes without craters(55)and multiple volcanoes(20).The classification presented in this paper makes it possible to include all morphological types of volcanoes found in the region.This fact also renders the present classification a useful tool to apply in other,both insular and continental volcanic areas to eventually analyze and systematize the study of eruptive edifices with similar traits.Hence,this research will explore the standard physical volcanology literature so as to follow accepted definitions.展开更多
This is a correction to:Isabela R R Moraes,Mariana Antunes,Laura S Lopez-Greco,Fernando Jose Zara,Antonio Leao Castilho,Functional reproductive morphology of the snapping shrimp genus Synalpheus Spence Bate,1888(Decap...This is a correction to:Isabela R R Moraes,Mariana Antunes,Laura S Lopez-Greco,Fernando Jose Zara,Antonio Leao Castilho,Functional reproductive morphology of the snapping shrimp genus Synalpheus Spence Bate,1888(Decapoda,Alpheidae),Current Zoology,2024,71,338-352;https:/doi.org/10.1093/cz/zoae053.展开更多
Morphology,the study of shapes or forms,when applied to tourism,emphasizes the multifarious spatial practices between morphological elements and tourism activities.However,existing literature on morphology in the cont...Morphology,the study of shapes or forms,when applied to tourism,emphasizes the multifarious spatial practices between morphological elements and tourism activities.However,existing literature on morphology in the context of tourism usually only focuses on a single or a limited number of study areas,overlooking common or even universal patterns across various tourism destinations.To address this gap,we utilize geospatial big data and present a case study on the morphology of 406“AAAAA”-rated scenic areas in China.A framework based on“points”,“lines”,“planes”,and“solids”was designed to systematically organize and analyze morphological elements across scenic areas.The findings provide valuable insights for tourism planning and development,such as the co-occurrence of dense road networks and fragmented landscapes within scenic areas,as well as the resourcecontext-influenced(cultural or natural)associations between morphological features and tourism indicators.This research provides valuable strategic guidance for more effective and informed tourism development while acknowledging the trade-offs between generalizability and local specificity.展开更多
Cryptocaryon irritans is the parasite responsible for“white spot disease”in the yellowfin seabream Acanthopagrus latus,which has caused significant losses to the aquaculture industry.This experiment investigated the...Cryptocaryon irritans is the parasite responsible for“white spot disease”in the yellowfin seabream Acanthopagrus latus,which has caused significant losses to the aquaculture industry.This experiment investigated the changes in the morphology,transcriptome,and proteome of gill tissue in yellowfin seabream infected with C.irritans,aiming to provide foundational data for further understanding the pathogenic mechanisms and control measures against this parasite.The main findings were as follows,after C.irritans infection,the structure of gill tissue in yellowfin seabream was damaged,with microvessels ruptured,some cells proliferating,and large amounts of mucus infiltrating.Transcriptome analysis revealed a total of 4299 differentially expressed genes,with 2367 up-regulated and 1932down-regulated.Further bioinformatics analysis of all differentially expressed genes identified nine immune-related genes,cox-2,mcama,tbx21,dcn,tnfb,cd74a,illb,ppib,and cd4-1 in A.latus.The reliability of the transcriptome data was validated by real time q PCR,which showed the same trend as the RNA-seq results.Proteome analysis found365 differential proteins,with 180 proteins up-regulated and 185 proteins down-regulated.Bioinformatics analysis identified three immune-related proteins,Myll,Gapdh,and Actn3b.These findings indicated that C.irritans disrupted the structure of gill tissue,impeded gas exchange and led to asphyxiation and death in affected fish.Transcriptome and proteome analyses showed that the expression of immune-related genes and proteins in yellowfin seabream,involved not only inflammatory responses and the activation and migration of immune cells but also potentially participated in tissue repair and defense regulation.These findings highlighted the complex immune regulatory network in response to C.irritans infection,offering references for prevention and control of white spot disease in yellowfin seabream.展开更多
Deep-sea aquaculture is an emerging trend due to the contamination and overexploitation of nearshore mariculture areas.However,the complex water conditions in the deep sea impose higher demands on the swimming perform...Deep-sea aquaculture is an emerging trend due to the contamination and overexploitation of nearshore mariculture areas.However,the complex water conditions in the deep sea impose higher demands on the swimming performance of farmed animals.Spotted sea bass(Lateolabrax maculatus)is one of the most economically important fish species in China.To investigate the mechanisms underlying the individual variations in swimming performance among spotted sea bass,we measured their critical swimming speed(U_(crit))and morphological phenotypes.Total length,body length,body weight,caudal region length,and condition factor showed significant positive correlations with absolute Ucrit.In contrast,caudal fin length and pectoral fin length tended to hinder the swimming performance of individual spotted sea bass.Additionally,white muscle tissues from fish exhibiting good swimming performance(relative U_(crit)>8.20 BL/s)and poor swimming performance(relative U_(crit)<7.31 BL/s)were sampled for RNA-seq.A total of 694 differential expression genes(DEGs)were identified through gene expression analysis,with significant enrichment in GO terms such as mitochondrial protein complex,ribosomal subunit,structural constituent of ribosome,and oxidative phosphorylation,as well as genes in KEGG pathways including ribosome and metabolic pathways.In conclusion,our study for the first time comprehensively elucidated the impact of morphology of spotted sea bass on its individual differences in swimming ability,and analyzed the genetic basis underlying swimming ability using transcriptomic methods.This study provides a theoretical basis for the potential breeding varieties of spotted sea bass suitable for deep-sea aquaculture.展开更多
This study aims to develop a high-precision and cost-efficient method for the threedimensional reconstruction of large particles in natural gravel and blasted rock fragments,utilizing Structure from Motion(SfM)and Mul...This study aims to develop a high-precision and cost-efficient method for the threedimensional reconstruction of large particles in natural gravel and blasted rock fragments,utilizing Structure from Motion(SfM)and Multi-View Stereo(MVS)techniques.The proposed approach was applied to characterize the three-dimensional morphology of rockfill dam materials at a real construction site.Particle shape was quantitatively analyzed using shape indices of sphericity,convexity,and angularity.The predominant morphology of natural gravel is characterized as slightly elongated and slightly flat,while rock fragments are slightly elongated and not flat.Probability density distributions of shape indices follow a skewed normal distribution:sphericity and convexity show leftward skewness,whereas angularity is right-skewed.Skewness parameters of sphericity and angularity are consistent between natural gravel and blasted rock fragments,indicating comparable shape asymmetry.Convexity skewness is significantly higher in natural gravel compared to rock fragments,by approximately an order of magnitude.The relationship between size and particle shape shows that form ratios and associated shape descriptors change linearly with the logarithm of size;larger particles approach spherical or cubic forms.The innovative measurements contribute to the particle shape data set of rockfill dam materials,providing valuable insights into the three-dimensional and statistical morphological characteristics of relatively large particles in natural gravel and blasted rock fragments.This approach enhances understanding of particle morphology's impact on the mechanical behavior of granular materials.展开更多
The East China Sea(ECS)off the Coast of Zhoushan Archipelago,Zhejiang(ECS-CZA)is home to abundant fishery resources and an important spawning,feeding,and nursing ground for a variety of fish species.Due to long-term o...The East China Sea(ECS)off the Coast of Zhoushan Archipelago,Zhejiang(ECS-CZA)is home to abundant fishery resources and an important spawning,feeding,and nursing ground for a variety of fish species.Due to long-term overfishing,the ichthyoplankton structure has been dramatically altered.Understanding the species composition and distribution of fish eggs and larvae is one of the most essential tasks to accurately regulate fishery resources and formulate effective management policies;however,little is known about the ichthyoplankton in this region.In this study,an integrated strategy of morphology identification(MI)and mitochondrial COI DNA barcoding was used to identify species of fish eggs and larvae collected from the ECSCZA.MI revealed 15 fish egg species belonging to 12 families and 12 fish larva species belonging to 12 families;in contrast,DNA barcoding altogether identified 30 species,including 18 fish egg species and 13 fish larva species.One species was shared between the egg and larva samples.Our study offers useful tools and critical scientific information for further understanding the diversity,distribution,and conservation management of various ichthyoplankton species in the marine environment.展开更多
This study explored the morphological characteristics and differences of the otoliths in three native species,Schizothorax biddulphi,S.eurystomus and S.curvifrons,in the Yarkand River of the Tarim River,Xinjiang,China...This study explored the morphological characteristics and differences of the otoliths in three native species,Schizothorax biddulphi,S.eurystomus and S.curvifrons,in the Yarkand River of the Tarim River,Xinjiang,China.A total of 93 specimens(27 S.biddulphi,39 S.eurystomus,and 27 S.curvifrons)were analyzed using six basic otolith morphological parameters(OA,R_(max),R_(min),OP,OL,OW)to derive six factors(F_(1),F_(2),F_(3),F_(4),F_(5),F_(6))and seven indices(RO,FF,CI,RE,EL,RR,AR)for morphological assessment.A discriminant analysis incorporating 77 Fourier coefficients of the otoliths revealed distinct morphological differences among the species.A significant power function relationship between otolith morphology and standard length was observed across the species,with R2 values ranging from 0.409 to 0.749.Principal component analysis(PCA)of 7 traditional otolith morphological indicators explained 81.243%of the variance,yielding an overall species discrimination rate of 81.65%.Further PCA of 77 Fourier harmonic values enhanced the discrimination accuracy,with the first 3 components accounting for 77.49%of the total variation and an improved discrimination rate of 100.00%.Cluster analysis resulted in the grouping of S.biddulphi and S.curvifrons together and revealed their association with S.eurystomus,indicating notable morphological distinctions.Both otolith shape indices and elliptical Fourier analysis have been useful in distinguishing the phenotypic units of different fish species.In this study,otolith morphology was applied for the first time to identify Schizothorax species,providing an in-depth description of species distribution and evolutionary history.This study provides a reference for the identification and systematic classification of Schizothorax species and a scientific basis for formulating effective species protection measures,for promoting the sustainable management of species and important habitats.展开更多
A high-quality welding method,named plasma arc welding apparatus with rotating tungsten electrode(abbreviated as PAW-RT),was proposed in this paper.The rotation speed could be adjusted from 0 to 15000 r/min.The rotary...A high-quality welding method,named plasma arc welding apparatus with rotating tungsten electrode(abbreviated as PAW-RT),was proposed in this paper.The rotation speed could be adjusted from 0 to 15000 r/min.The rotary motion of the tungsten needle trans-ferred circumferential momentum to the arc as well as the molten pool,thereby conferring the latter with rotating fluid flow charac-teristics.The influences of tungsten electrode rotation speed on PAW arc morphology,weld formation and interfacial microstructure of the final weld joints were discussed by the experimental procedures involving in-situ ablation,surfacing and butt welding.The ex-periments were conducted on Q235B steel.The results indicated that the increase of tungsten electrode rotation speed in PAW-RT contributed to improving arc eccentricity,leading to aesthetically improved welds with more uniformity.Additionally,the strength,hardness and toughness of the welded joint increased,while porosity was reduced.展开更多
The toughness of thermoplastic polymers such as polypropylene(PP)can be improved by adding elastomers-based toughening agents,and the phase morphology of these toughening agents is very important for the strength and ...The toughness of thermoplastic polymers such as polypropylene(PP)can be improved by adding elastomers-based toughening agents,and the phase morphology of these toughening agents is very important for the strength and toughness of PP.The low-temperature toughness of PP was improved by inserting high-density polyethylene(HDPE)between PP and polystyrene-b-ethylene-co-propyleneb-polystyrene(SEPS)to form an unusual SEPS@HDPE core–shell structure,with SEPS as the core and HDPE as the shell.Based on the microtopography and rheological behavior characterization,HDPE in PP/SEPS/HDPE composites was found to serve as an emulsifier,decrease the size of SEPS particles,and promote the homogeneous dispersion of dispersed phase particles in the matrix.An increase in the HDPE content shifted the toughening mechanism of PP composites from cavitation to matrix shear yielding.The reduction in the distance between the dispersed core–shell structure particles promoted shear yielding in the PP composites,leading to increased toughness.The creation of an intermediate HDPE layer with a moderate modulus was crucial for dispersing stress concentrations and significantly improving toughness without compromising the tensile strength.These findings will facilitate the fabrication of high-toughness PP products at low temperatures.展开更多
Accurately acquiring catalyst size and morphology is essential for supporting catalytic reaction process design and optimal control. We report an intelligent catalyst sizing and morphological classification method bas...Accurately acquiring catalyst size and morphology is essential for supporting catalytic reaction process design and optimal control. We report an intelligent catalyst sizing and morphological classification method based on the Mask-RCNN framework. A dataset of 9880 high-resolution images was captured by using a self-made fiber-optic endoscopic system for 13 kinds of silicoaluminophosphate-34 (SAPO-34) catalyst samples with different coke. Then there were approximately 877881 individual particles extracted from this dataset by our AI-based particle recognition algorithm. To clearly describe the morphology of irregular particles, we proposed a hybrid classification criterion that combines five different parameters, which are deformity, circularity, roundness, aspect ratio, and compactness. Therefore, catalyst morphology can be classified into two categories with four types. The first category includes regular types, such as the spherical, ellipsoidal, and rod-shaped types. And all the irregular types fall into the second category. The experimental results showed that a catalyst particle tends to be larger when its coke deposition increased. Whereas particle morphology remained primarily spherical and ellipsoidal, the ratio of each type varied slightly according to its coke. Our findings illustrate that this is a promising approach to be developing intelligent instruments for catalyst particle sizing and classification.展开更多
Multimaterial digital light processing(DLP)three-dimensional(3D)printing technology provides unique advantages in the field of multi material additive manufacturing(MM AM)with its high resolution and rapid shaping cap...Multimaterial digital light processing(DLP)three-dimensional(3D)printing technology provides unique advantages in the field of multi material additive manufacturing(MM AM)with its high resolution and rapid shaping capabilities based on photopolymerization.However,owing to differences in the curing behavior and physical properties of different materials,multimaterial DLP 3D printing faces challenges such as insufficient interfacial bonding strength and unstable mechanical properties.In this study,two resins were integrated by multimaterial DLP 3D printing technology,and the effects of different layer thicknesses and exposure times on the interfacial bonding strength and morphology of the multimaterials were systematically investigated.The interfacial bonding mechanisms of the two resins was analyzed.It was found that increasing the exposure time can improve the interfacial bonding strength between materials,but certain limitations exist.A mathematical model relating the interfacial bonding strength to the exposure time and layer thickness was developed,and optimal process parameters were determined using optimization algorithms.A variable-parameter printing strategy for the interface was proposed to further improve the performance of printed parts.The maximum tensile strength of the multimaterial samples(44.43 MPa)using this strategy reached that of single-material parts(45 MPa),validating the feasibility of this strategy.This provides guidance for multimaterial DLP 3D printing processes and offers valuable insights for the future additive manufacturing of high-performance multimaterial components.展开更多
The structural phase transition of MnO_(2) nanorods was investigated using in situ high pressure synchrotron x-ray diffraction(XRD) and transmission electron microscopy(TEM). At pressures exceeding 10.9 GPa, a second-...The structural phase transition of MnO_(2) nanorods was investigated using in situ high pressure synchrotron x-ray diffraction(XRD) and transmission electron microscopy(TEM). At pressures exceeding 10.9 GPa, a second-order structural phase transition from tetragonal to orthogonal, which was accompanied by fine-scale crystal twinning phenomena, was observed in MnO_(2) nanorods. On account of the significant contribution of surface energy, the phase transition pressure exhibited appreciable hysteresis compared with the bulk counterparts, suggesting the enhanced structural stability of nanorod morphology. These findings reveal that the size and morphology exhibit a manifest correlation with the high pressure behavior of MnO_(2) nanomaterials, providing useful insights into the intricate interplay between structure and properties.展开更多
The sedimentary bed morphology modulated by the wake flow of a wall-mounted flexible aquatic vegetation blade across various structural aspect ratios(A_(R)=l/b,where l and b are the length and width of the blade,respe...The sedimentary bed morphology modulated by the wake flow of a wall-mounted flexible aquatic vegetation blade across various structural aspect ratios(A_(R)=l/b,where l and b are the length and width of the blade,respectively)and incoming flow velocities was experimentally investigated in a water channel.A surface scanner was implemented to quantify bed topography,and a tomographic particle image velocimetry system was used to characterize the three-dimensional wake flows.The results showed that due to the deflection of incoming flow,the velocity magnitude increased at the lateral sides of the blade,thereby producing distinctive symmetric scour holes in these regions.The normalized morphology profiles of the sedimentary bed,which were extracted along the streamwise direction at the location of the maximum erosion depth,exhibited a self-similar pattern that closely followed a sinusoidal wave profile.The level of velocity magnitude enhancement was highly correlated to the postures of the flexible blade.At a given flow velocity,the blade with lower aspect ratios exhibited less significant deformation,causing more significant near-bed velocity enhancement in the wake deflection zone and therefore leading to higher erosion volumes.Further investigation indicated that when the blade underwent slight deformation,the larger velocity enhancement close to the bed can be attributed to more significant flow deflection effects at the lateral sides of the blade and stronger flow mixing with high momentum flows away from the bed.Supported with measurements,a basic formula was established to quantify the shear stress acting on the sedimentary bed as a function of incoming flow velocity and blade aspect ratio.展开更多
Aerosol category and its physicochemical properties are key factors influencing its climate and environmental effects.To further enhance our understanding of aerosols in the Himalayas-Tibetan Plateau region,atmospheri...Aerosol category and its physicochemical properties are key factors influencing its climate and environmental effects.To further enhance our understanding of aerosols in the Himalayas-Tibetan Plateau region,atmospheric particulate matter samples were collected at three different altitudes on Mount Qomolangma(Everest).Using an automated scanning electron microscope system,the composition,size,and morphology of 52,349 particles were analyzed.The average mass concentrations of PM_(1),PM_(2.5),and PM_(10)were 0.678,5.054,and 16.698μg/m^(3),respectively.Aluminosilicate particles dominated the samples,accounting for 71.5%to 82.8%of PM_(10)mass and 34.7%to 62.4%of the particle number.Quartz particles,carbonate particles,metal oxides,and sulfates were also observed at different periods.Carbonaceous particles made up a significant portion of aerosols,comprising 2.1%to 9.7%of PM_(10)mass and 10.4%to 45.4%of particle number,with their concentration showing an upward trend with altitude.Small amounts of tar ball particles and fly ash particles were also observed,providing direct evidence of anthropogenic influences on high-altitude regions,even at altitudes exceeding 6000 m.The size distribution and abundance of different particle categories were closely related to the transport trajectories of air masses.The morphology of different particle categories varied,with fly ash particles mainly spherical and carbonaceous particles exhibiting higher irregularity.展开更多
基金funded by the National Natural Science F oundation of China(No.52172205)。
文摘Zinc oxide(ZnO)serves as a crucial functional semiconductor with a wide direct bandgap of approximately 3.37 eV.Solvothermal reaction is commonly used in the synthesis of ZnO micro/nanostructures,given its low cost,simplicity,and easy implementation.Moreover,ZnO morphology engineering has become desirable through the alteration of minor conditions in the reaction process,particularly at room temperature.In this work,ZnO micro/nanostructures were synthesized in a solution by varying the amounts of the ammonia added at low temperatures(including room temperature).The formation of Zn^(2+)complexes by ammonia in the precursor regulated the reaction rate of the morphology engineering of ZnO,which resulted in various structures,such as nanoparticles,nanosheets,microflowers,and single crystals.Finally,the obtained ZnO was used in the optoelectronic application of ultraviolet detectors.
基金funded by the National Science Centre,Poland,on the basis of the decision number UMO-2020/37/B/ST8/02097supported by the program“Excellence Initiative-Research University”for the AGH University of Krakow(IDUB AGH,No.501.696.7996,Action 4,ID 9880).
文摘Multicomponent Gd_(1−x)Sm_(x)Ba_(0.5)Sr_(0.5)CoCuO_(5+δ)double perovskites are optimized for application in terms of chemical composi-tion and morphology for the use as oxygen electrodes in solid oxide cells.Structural studies of other physicochemical properties are con-ducted on a series of materials obtained by the sol-gel method with different ratios of Gd and Sm cations.It is documented that changing the x value,and the resulting adjustment of the average ionic radius,have a significant impact on the crystal structure,stability,as well as on the total conductivity and thermomechanical properties of the materials,with the best results obtained for the Gd_(0.75)Sm_(0.2)5Ba_(0.5)Sr_(0.5)CoCuO_(5+δ)composition.Oxygen electrodes are prepared using the selected compound,allowing to obtain low polarization resistance values,such as 0.086Ω·cm^(2)at 800℃.Systematic studies of electrocatalytic activity are conducted using La_(0.8)Sr_(0.2)Ga_(0.8)Mg_(_(0.2))O_(3−δ)as the electrolyte for all electrodes,and Ce_(0.8)Gd_(0.2)O_(2−δ)electrolyte for the best performing Gd_(0.75)Sm_(0.2)5Ba_(0.5)Sr_(0.5)CoCuO_(5+δ)electrodes.The electrochemical data are analyzed using the distribution of relaxation times method.Also,the influence of the preparation method of the electrode material is in-ve`stigated using the electrospinning technique.Finally,the performance of the Gd_(0.75)Sm_(0.2)5Ba_(0.5)Sr_(0.5)CoCuO_(5+δ)electrodes is tested in a Ni-YSZ(yttria-stabilized zirconia)anode-supported cell with a Ce_(0.8)Gd_(0.2)O_(2−δ)buffer layer,in the fuel cell and electrolyzer operating modes.With the electrospun electrode,a power density of 462 mW·cm^(−2)is obtained at 700℃,with a current density of ca.0.2 A·cm^(−2)at 1.3 V for the electrolysis at the same temperature,indicating better performance compared to the sol-gel-based electrode.
基金supported by the National Key Research and Development Program of China,No.2021ZD0202503(to AHT)the National Natural Science Foundation of China,Nos.31872759(to AHT)and 32070707(to CF)+1 种基金Shenzhen Science and Technology Program,No.RCJC20210609104333007(to ZW)Shenzhen-Hong Kong Institute of Brain Science,Shenzhen Fundamental Research Institutions,No.2021SHIBS0002(to ZW).
文摘Morphological alterations in dendritic spines have been linked to changes in functional communication between neurons that affect learning and memory.Kinesin-4 KIF21A helps organize the microtubule-actin network at the cell cortex by interacting with KANK1;however,whether KIF21A modulates dendritic structure and function in neurons remains unknown.In this study,we found that KIF21A was distributed in a subset of dendritic spines,and that these KIF21A-positive spines were larger and more structurally plastic than KIF21A-negative spines.Furthermore,the interaction between KIF21A and KANK1 was found to be critical for dendritic spine morphogenesis and synaptic plasticity.Knockdown of either KIF21A or KANK1 inhibited dendritic spine morphogenesis and dendritic branching,and these deficits were fully rescued by coexpressing full-length KIF21A or KANK1,but not by proteins with mutations disrupting direct binding between KIF21A and KANK1 or binding between KANK1 and talin1.Knocking down KIF21A in the hippocampus of rats inhibited the amplitudes of long-term potentiation induced by high-frequency stimulation and negatively impacted the animals’cognitive abilities.Taken together,our findings demonstrate the function of KIF21A in modulating spine morphology and provide insight into its role in synaptic function.
文摘Introduction: the left atrial appendage, a dormant embryonic vestige, would play a major role in cardiac hemodynamic changes, volume homeostasis and thrombi formation. It, therefore constitutes a therapeutic target. Its morphology is extremely variable. Objective: it consisted on determining the morphological variations of the left auricle as well as their interest in the prevention of thrombi in the Senegalese. Material and Method: This study was conducted by dissecting 36 fresh hearts from Senegalese anatomical subjects with a sampling of the left atrial appendage, including specimens with normal morphological appearance. Their morphology was studied using the fresh and frozen plaster molding method. The data obtained were analyzed statistically. Results: the average age of the subjects was 33 years, with a sex ratio of 1.06, the cauliflower shape was dominant with 57% of cases and the cactus shape (4%) was less frequent. The cauliflower shape presented a clear angulation compared to the others without statistically significant differences according to age. Conclusion: This work showed a great morphological variability of the left atrial appendage. It can provide an update on the specificity of Senegalese. Taking these variations into account is important in the safe management of hemodynamic conditions and the improvement of the management of recurrent strokes.
基金supported by the National Natural Science Foundation of China(22376063,21976057)the Fund of the National Engineering Laboratory for Mobile Source Emission Control Technology(NELMS2020A05)Fundamental Research Funds for the Central Universities.
文摘The preferential oxidation of CO(CO-PROX)reaction is a cost-effective method for eliminating trace amounts of CO from the fuel H2.Pt-based catalysts have been extensively studied for COPROX,with their activity influenced by the morphology of the support.Hydrothermal synthesis was employed to produce different morphologies ofγ-Al_(2)O_(3):flower-likeγ-Al_(2)O_(3)(f)exposing(110)crystal faces,sheet-likeγ-Al_(2)O_(3)(s)revealing(100)crystal faces,and rod-likeγ-Al_(2)O_(3)(r)displaying(111)crystal faces,followed by loading PtCo nanoparticles.The exposed crystal faces of the support impact the alloying degree of the PtCo nanoparticles,and an increase in the alloying degree correlates with enhanced catalyst reactivity.Pt_(3)Co intermetallic compounds were identified onγ-Al_(2)O_(3)(f)exposing(110)crystal faces,and PtCo/γ-Al_(2)O_(3)(f)showed high catalytic activity in the CO-PROX reaction,achieving 100%CO conversion across a broad temperature range of 50−225°C.In contrast,only partial alloying of PtCo was observed onγ-Al_(2)O_(3)(s).Furthermore,no alloying between Pt and Co occurred in PtCo/γ-Al_(2)O_(3)(r),resulting in a reaction rate at 50°C that was merely 11%of that of PtCo/γ-Al_(2)O_(3)(f).The formation of Pt3Co intermetallic compounds led to a more oxidized state of Pt,which significantly diminished the adsorption of CO on Pt and augmented the active oxygen species,thereby facilitating the selective oxidation of CO.
文摘Harrat Lunayyir,a volcanic field in western Saudi Arabia,exhibits diverse geomorphological and topographical features shaped by volcanic,tectonic,and climatic processes.This study integrates field observations,remote sensing,and GIS analysis to investigate the spatial distribution and relationships between volcanic landforms,lava flows,and topographical variation result obtained is a morphological classification of the cinder cones of Harrat Lunayyir,which can be sub-divided into four types:tephra rings,horseshoe-shaped volcanoes,multiple volcanoes and volcanoes without craters.All of these are monogenetic volcanoes,unlike central volcanoes(stratovolcanoes)which live for tens or hundreds of thousands of years and erupt numerous times.In Harrat Lunayyir,there is a clear dominance of arched horseshoe-shaped volcanoes(58)over ring-shaped cinder cones(10),A1_symmetric cones(circular,uniform cinder cones with a single crater)(32),A2_asymmetric cones(elongated,irregular cones and may feature one or more craters)(8),volcanoes without craters(55)and multiple volcanoes(20).The classification presented in this paper makes it possible to include all morphological types of volcanoes found in the region.This fact also renders the present classification a useful tool to apply in other,both insular and continental volcanic areas to eventually analyze and systematize the study of eruptive edifices with similar traits.Hence,this research will explore the standard physical volcanology literature so as to follow accepted definitions.
文摘This is a correction to:Isabela R R Moraes,Mariana Antunes,Laura S Lopez-Greco,Fernando Jose Zara,Antonio Leao Castilho,Functional reproductive morphology of the snapping shrimp genus Synalpheus Spence Bate,1888(Decapoda,Alpheidae),Current Zoology,2024,71,338-352;https:/doi.org/10.1093/cz/zoae053.
基金Yunnan Provincial Science and Technology Project at Southwest United Graduate School,No.202302AO370012National Natural Science Foundation of China,No.42401510Postdoctoral Fellowship Program of CPSF,No.GZC20240017。
文摘Morphology,the study of shapes or forms,when applied to tourism,emphasizes the multifarious spatial practices between morphological elements and tourism activities.However,existing literature on morphology in the context of tourism usually only focuses on a single or a limited number of study areas,overlooking common or even universal patterns across various tourism destinations.To address this gap,we utilize geospatial big data and present a case study on the morphology of 406“AAAAA”-rated scenic areas in China.A framework based on“points”,“lines”,“planes”,and“solids”was designed to systematically organize and analyze morphological elements across scenic areas.The findings provide valuable insights for tourism planning and development,such as the co-occurrence of dense road networks and fragmented landscapes within scenic areas,as well as the resourcecontext-influenced(cultural or natural)associations between morphological features and tourism indicators.This research provides valuable strategic guidance for more effective and informed tourism development while acknowledging the trade-offs between generalizability and local specificity.
基金Fujian Province Science and Technology Plan Project under contract No.2023N0011Xiamen Municipal Bureau of Marine Development Project under contract No.S24258。
文摘Cryptocaryon irritans is the parasite responsible for“white spot disease”in the yellowfin seabream Acanthopagrus latus,which has caused significant losses to the aquaculture industry.This experiment investigated the changes in the morphology,transcriptome,and proteome of gill tissue in yellowfin seabream infected with C.irritans,aiming to provide foundational data for further understanding the pathogenic mechanisms and control measures against this parasite.The main findings were as follows,after C.irritans infection,the structure of gill tissue in yellowfin seabream was damaged,with microvessels ruptured,some cells proliferating,and large amounts of mucus infiltrating.Transcriptome analysis revealed a total of 4299 differentially expressed genes,with 2367 up-regulated and 1932down-regulated.Further bioinformatics analysis of all differentially expressed genes identified nine immune-related genes,cox-2,mcama,tbx21,dcn,tnfb,cd74a,illb,ppib,and cd4-1 in A.latus.The reliability of the transcriptome data was validated by real time q PCR,which showed the same trend as the RNA-seq results.Proteome analysis found365 differential proteins,with 180 proteins up-regulated and 185 proteins down-regulated.Bioinformatics analysis identified three immune-related proteins,Myll,Gapdh,and Actn3b.These findings indicated that C.irritans disrupted the structure of gill tissue,impeded gas exchange and led to asphyxiation and death in affected fish.Transcriptome and proteome analyses showed that the expression of immune-related genes and proteins in yellowfin seabream,involved not only inflammatory responses and the activation and migration of immune cells but also potentially participated in tissue repair and defense regulation.These findings highlighted the complex immune regulatory network in response to C.irritans infection,offering references for prevention and control of white spot disease in yellowfin seabream.
基金National Key R&D Program of China(No.2022YFD2400103).
文摘Deep-sea aquaculture is an emerging trend due to the contamination and overexploitation of nearshore mariculture areas.However,the complex water conditions in the deep sea impose higher demands on the swimming performance of farmed animals.Spotted sea bass(Lateolabrax maculatus)is one of the most economically important fish species in China.To investigate the mechanisms underlying the individual variations in swimming performance among spotted sea bass,we measured their critical swimming speed(U_(crit))and morphological phenotypes.Total length,body length,body weight,caudal region length,and condition factor showed significant positive correlations with absolute Ucrit.In contrast,caudal fin length and pectoral fin length tended to hinder the swimming performance of individual spotted sea bass.Additionally,white muscle tissues from fish exhibiting good swimming performance(relative U_(crit)>8.20 BL/s)and poor swimming performance(relative U_(crit)<7.31 BL/s)were sampled for RNA-seq.A total of 694 differential expression genes(DEGs)were identified through gene expression analysis,with significant enrichment in GO terms such as mitochondrial protein complex,ribosomal subunit,structural constituent of ribosome,and oxidative phosphorylation,as well as genes in KEGG pathways including ribosome and metabolic pathways.In conclusion,our study for the first time comprehensively elucidated the impact of morphology of spotted sea bass on its individual differences in swimming ability,and analyzed the genetic basis underlying swimming ability using transcriptomic methods.This study provides a theoretical basis for the potential breeding varieties of spotted sea bass suitable for deep-sea aquaculture.
基金National Natural Science Foundation of China,Grant/Award Numbers:51809290,51979093,52239009Project funded by Tibet Autonomous Region Key R&D Plan,Grant/Award Number:XZ202101ZY0002GPostgraduate Research&Practice Innovation Program of Jiangsu Province,Grant/Award Number:No.KYCX22_0656。
文摘This study aims to develop a high-precision and cost-efficient method for the threedimensional reconstruction of large particles in natural gravel and blasted rock fragments,utilizing Structure from Motion(SfM)and Multi-View Stereo(MVS)techniques.The proposed approach was applied to characterize the three-dimensional morphology of rockfill dam materials at a real construction site.Particle shape was quantitatively analyzed using shape indices of sphericity,convexity,and angularity.The predominant morphology of natural gravel is characterized as slightly elongated and slightly flat,while rock fragments are slightly elongated and not flat.Probability density distributions of shape indices follow a skewed normal distribution:sphericity and convexity show leftward skewness,whereas angularity is right-skewed.Skewness parameters of sphericity and angularity are consistent between natural gravel and blasted rock fragments,indicating comparable shape asymmetry.Convexity skewness is significantly higher in natural gravel compared to rock fragments,by approximately an order of magnitude.The relationship between size and particle shape shows that form ratios and associated shape descriptors change linearly with the logarithm of size;larger particles approach spherical or cubic forms.The innovative measurements contribute to the particle shape data set of rockfill dam materials,providing valuable insights into the three-dimensional and statistical morphological characteristics of relatively large particles in natural gravel and blasted rock fragments.This approach enhances understanding of particle morphology's impact on the mechanical behavior of granular materials.
文摘The East China Sea(ECS)off the Coast of Zhoushan Archipelago,Zhejiang(ECS-CZA)is home to abundant fishery resources and an important spawning,feeding,and nursing ground for a variety of fish species.Due to long-term overfishing,the ichthyoplankton structure has been dramatically altered.Understanding the species composition and distribution of fish eggs and larvae is one of the most essential tasks to accurately regulate fishery resources and formulate effective management policies;however,little is known about the ichthyoplankton in this region.In this study,an integrated strategy of morphology identification(MI)and mitochondrial COI DNA barcoding was used to identify species of fish eggs and larvae collected from the ECSCZA.MI revealed 15 fish egg species belonging to 12 families and 12 fish larva species belonging to 12 families;in contrast,DNA barcoding altogether identified 30 species,including 18 fish egg species and 13 fish larva species.One species was shared between the egg and larva samples.Our study offers useful tools and critical scientific information for further understanding the diversity,distribution,and conservation management of various ichthyoplankton species in the marine environment.
基金Supported by the National Natural Science Foundation of China(No.31360635)the Tianshan Talent Training Project of Xinjiang(No.2023 TSYCCX 0128)the Science and Technology Public Relations Planning in Key Fields of the XPCC Science and Technology Bureau(No.2022 DB 019)。
文摘This study explored the morphological characteristics and differences of the otoliths in three native species,Schizothorax biddulphi,S.eurystomus and S.curvifrons,in the Yarkand River of the Tarim River,Xinjiang,China.A total of 93 specimens(27 S.biddulphi,39 S.eurystomus,and 27 S.curvifrons)were analyzed using six basic otolith morphological parameters(OA,R_(max),R_(min),OP,OL,OW)to derive six factors(F_(1),F_(2),F_(3),F_(4),F_(5),F_(6))and seven indices(RO,FF,CI,RE,EL,RR,AR)for morphological assessment.A discriminant analysis incorporating 77 Fourier coefficients of the otoliths revealed distinct morphological differences among the species.A significant power function relationship between otolith morphology and standard length was observed across the species,with R2 values ranging from 0.409 to 0.749.Principal component analysis(PCA)of 7 traditional otolith morphological indicators explained 81.243%of the variance,yielding an overall species discrimination rate of 81.65%.Further PCA of 77 Fourier harmonic values enhanced the discrimination accuracy,with the first 3 components accounting for 77.49%of the total variation and an improved discrimination rate of 100.00%.Cluster analysis resulted in the grouping of S.biddulphi and S.curvifrons together and revealed their association with S.eurystomus,indicating notable morphological distinctions.Both otolith shape indices and elliptical Fourier analysis have been useful in distinguishing the phenotypic units of different fish species.In this study,otolith morphology was applied for the first time to identify Schizothorax species,providing an in-depth description of species distribution and evolutionary history.This study provides a reference for the identification and systematic classification of Schizothorax species and a scientific basis for formulating effective species protection measures,for promoting the sustainable management of species and important habitats.
基金supported by the National Natural Science Foundation of China(U22B20127)the National Natural Science Foundation of China(52175305)Taishan Scholars Project(tstp20230618).
文摘A high-quality welding method,named plasma arc welding apparatus with rotating tungsten electrode(abbreviated as PAW-RT),was proposed in this paper.The rotation speed could be adjusted from 0 to 15000 r/min.The rotary motion of the tungsten needle trans-ferred circumferential momentum to the arc as well as the molten pool,thereby conferring the latter with rotating fluid flow charac-teristics.The influences of tungsten electrode rotation speed on PAW arc morphology,weld formation and interfacial microstructure of the final weld joints were discussed by the experimental procedures involving in-situ ablation,surfacing and butt welding.The ex-periments were conducted on Q235B steel.The results indicated that the increase of tungsten electrode rotation speed in PAW-RT contributed to improving arc eccentricity,leading to aesthetically improved welds with more uniformity.Additionally,the strength,hardness and toughness of the welded joint increased,while porosity was reduced.
基金supported by the Taiyuan Major Science and Technology Project Fund in 2021,Fund for Shanxi“1331 Project,”Key Research and Development Program of Shanxi Province(202102040201011)the Zhanjiang Marine Equipment and Marine Biological Industry Unveiled the Talent Team Project(2021E05034).
文摘The toughness of thermoplastic polymers such as polypropylene(PP)can be improved by adding elastomers-based toughening agents,and the phase morphology of these toughening agents is very important for the strength and toughness of PP.The low-temperature toughness of PP was improved by inserting high-density polyethylene(HDPE)between PP and polystyrene-b-ethylene-co-propyleneb-polystyrene(SEPS)to form an unusual SEPS@HDPE core–shell structure,with SEPS as the core and HDPE as the shell.Based on the microtopography and rheological behavior characterization,HDPE in PP/SEPS/HDPE composites was found to serve as an emulsifier,decrease the size of SEPS particles,and promote the homogeneous dispersion of dispersed phase particles in the matrix.An increase in the HDPE content shifted the toughening mechanism of PP composites from cavitation to matrix shear yielding.The reduction in the distance between the dispersed core–shell structure particles promoted shear yielding in the PP composites,leading to increased toughness.The creation of an intermediate HDPE layer with a moderate modulus was crucial for dispersing stress concentrations and significantly improving toughness without compromising the tensile strength.These findings will facilitate the fabrication of high-toughness PP products at low temperatures.
基金supported by the National Natural Science Foundation of China(22308348)the Natural Science Foundation of Liaoning Province of China(2024-MSBA-65)+1 种基金the Qin Chuangyuan Project for Introducing High-Level Innovative and Entrepreneurial Talents(QCYRCXM-2023-024)the Energy Revolution S&T Program of Yulin Innovation Institute of Clean Energy(E201041206).
文摘Accurately acquiring catalyst size and morphology is essential for supporting catalytic reaction process design and optimal control. We report an intelligent catalyst sizing and morphological classification method based on the Mask-RCNN framework. A dataset of 9880 high-resolution images was captured by using a self-made fiber-optic endoscopic system for 13 kinds of silicoaluminophosphate-34 (SAPO-34) catalyst samples with different coke. Then there were approximately 877881 individual particles extracted from this dataset by our AI-based particle recognition algorithm. To clearly describe the morphology of irregular particles, we proposed a hybrid classification criterion that combines five different parameters, which are deformity, circularity, roundness, aspect ratio, and compactness. Therefore, catalyst morphology can be classified into two categories with four types. The first category includes regular types, such as the spherical, ellipsoidal, and rod-shaped types. And all the irregular types fall into the second category. The experimental results showed that a catalyst particle tends to be larger when its coke deposition increased. Whereas particle morphology remained primarily spherical and ellipsoidal, the ratio of each type varied slightly according to its coke. Our findings illustrate that this is a promising approach to be developing intelligent instruments for catalyst particle sizing and classification.
基金supported by National Key R&D Program of China(Grant No.2022YFB4600103)National Youth Talent Support Program,China Postdoctoral Science Foundation(Grant No.2021M692555)+1 种基金Shaanxi Province Qinchuangyuan'Scientists+Engineers'Team Building Project(Grant No.2023KXJ-266)Fundamental Research Funds for the Central Universities(Grant No.xzy012023145)。
文摘Multimaterial digital light processing(DLP)three-dimensional(3D)printing technology provides unique advantages in the field of multi material additive manufacturing(MM AM)with its high resolution and rapid shaping capabilities based on photopolymerization.However,owing to differences in the curing behavior and physical properties of different materials,multimaterial DLP 3D printing faces challenges such as insufficient interfacial bonding strength and unstable mechanical properties.In this study,two resins were integrated by multimaterial DLP 3D printing technology,and the effects of different layer thicknesses and exposure times on the interfacial bonding strength and morphology of the multimaterials were systematically investigated.The interfacial bonding mechanisms of the two resins was analyzed.It was found that increasing the exposure time can improve the interfacial bonding strength between materials,but certain limitations exist.A mathematical model relating the interfacial bonding strength to the exposure time and layer thickness was developed,and optimal process parameters were determined using optimization algorithms.A variable-parameter printing strategy for the interface was proposed to further improve the performance of printed parts.The maximum tensile strength of the multimaterial samples(44.43 MPa)using this strategy reached that of single-material parts(45 MPa),validating the feasibility of this strategy.This provides guidance for multimaterial DLP 3D printing processes and offers valuable insights for the future additive manufacturing of high-performance multimaterial components.
基金Project supported by China Postdoctoral Science Foundation (Grant No. 2023M742049)Guangdong Basic and Applied Basic Research Foundation (Grant No. 2023A1515110844)the Innovative Training Program for College Students (Grant No. 20249076)。
文摘The structural phase transition of MnO_(2) nanorods was investigated using in situ high pressure synchrotron x-ray diffraction(XRD) and transmission electron microscopy(TEM). At pressures exceeding 10.9 GPa, a second-order structural phase transition from tetragonal to orthogonal, which was accompanied by fine-scale crystal twinning phenomena, was observed in MnO_(2) nanorods. On account of the significant contribution of surface energy, the phase transition pressure exhibited appreciable hysteresis compared with the bulk counterparts, suggesting the enhanced structural stability of nanorod morphology. These findings reveal that the size and morphology exhibit a manifest correlation with the high pressure behavior of MnO_(2) nanomaterials, providing useful insights into the intricate interplay between structure and properties.
基金supported by the National Science Foundation under Grant No.2327916.
文摘The sedimentary bed morphology modulated by the wake flow of a wall-mounted flexible aquatic vegetation blade across various structural aspect ratios(A_(R)=l/b,where l and b are the length and width of the blade,respectively)and incoming flow velocities was experimentally investigated in a water channel.A surface scanner was implemented to quantify bed topography,and a tomographic particle image velocimetry system was used to characterize the three-dimensional wake flows.The results showed that due to the deflection of incoming flow,the velocity magnitude increased at the lateral sides of the blade,thereby producing distinctive symmetric scour holes in these regions.The normalized morphology profiles of the sedimentary bed,which were extracted along the streamwise direction at the location of the maximum erosion depth,exhibited a self-similar pattern that closely followed a sinusoidal wave profile.The level of velocity magnitude enhancement was highly correlated to the postures of the flexible blade.At a given flow velocity,the blade with lower aspect ratios exhibited less significant deformation,causing more significant near-bed velocity enhancement in the wake deflection zone and therefore leading to higher erosion volumes.Further investigation indicated that when the blade underwent slight deformation,the larger velocity enhancement close to the bed can be attributed to more significant flow deflection effects at the lateral sides of the blade and stronger flow mixing with high momentum flows away from the bed.Supported with measurements,a basic formula was established to quantify the shear stress acting on the sedimentary bed as a function of incoming flow velocity and blade aspect ratio.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research(STEP)program(No.2019QZKK0106)the Basic Research Fund of CAMS(Nos.2023Z004 and 2023Z015).
文摘Aerosol category and its physicochemical properties are key factors influencing its climate and environmental effects.To further enhance our understanding of aerosols in the Himalayas-Tibetan Plateau region,atmospheric particulate matter samples were collected at three different altitudes on Mount Qomolangma(Everest).Using an automated scanning electron microscope system,the composition,size,and morphology of 52,349 particles were analyzed.The average mass concentrations of PM_(1),PM_(2.5),and PM_(10)were 0.678,5.054,and 16.698μg/m^(3),respectively.Aluminosilicate particles dominated the samples,accounting for 71.5%to 82.8%of PM_(10)mass and 34.7%to 62.4%of the particle number.Quartz particles,carbonate particles,metal oxides,and sulfates were also observed at different periods.Carbonaceous particles made up a significant portion of aerosols,comprising 2.1%to 9.7%of PM_(10)mass and 10.4%to 45.4%of particle number,with their concentration showing an upward trend with altitude.Small amounts of tar ball particles and fly ash particles were also observed,providing direct evidence of anthropogenic influences on high-altitude regions,even at altitudes exceeding 6000 m.The size distribution and abundance of different particle categories were closely related to the transport trajectories of air masses.The morphology of different particle categories varied,with fly ash particles mainly spherical and carbonaceous particles exhibiting higher irregularity.
