Optical tweezers technology has the characteristics of noncontact manipulation in three dimensions and steerable separation in solutions,and could be applied to obtain a separated sperm with high quality for intracyto...Optical tweezers technology has the characteristics of noncontact manipulation in three dimensions and steerable separation in solutions,and could be applied to obtain a separated sperm with high quality for intracytoplasmic sperm injection(ICSI).However,the effects of optical tweezers on sperm motility are still unclear.To elucidate the effects on sperm motility for optical tweezers,we systematically investigated the correlation between motility parameters and the parameters of optical tweezers(wavelength,power,trapping duration,and trapping orientation).Under three systems of optical tweezers with different laser wavelengths(1064,850,and 785 nm),the nine motility parameters of free swimming were mainly affected by trapping orientation(vertical/horizontal)and trapping duration.When 850 nm laser and 1064 nm laser are used,vertical trapping significantly reduces sperm free-swimming capability with prolonged exposure time,whereas horizontal trapping exhibits relatively minor interference on sperm motility.Notably,the 785 nm laser does not induce statistically significant changes in key parameters of sperm motility under any experimental conditions(trapping orientation and duration).For the rolling frequency of trapped sperm,horizontal trapping for three wavelengths has a negligible effect compared with vertical trapping,especially for the 785 nm laser.In conclusion,horizontal trapping can preserve sperm motility under low power(below 140mW at 1064 nm,below 100mW at 850nm,below 60mW at 785 nm)and short duration(below 4 min).This trapping duration is suffcient for the separation procedure of single live sperm in ICSI.This study provides critical parameter optimization guidelines for the safe application of optical tweezers technology in reproductive medicine.展开更多
Objectives:Non-suicidal self-injury(NSSI)represents a prominent and escalating concern within mental health,associated with considerable psychological and physical dangers.Peer victimization is identified as a signifi...Objectives:Non-suicidal self-injury(NSSI)represents a prominent and escalating concern within mental health,associated with considerable psychological and physical dangers.Peer victimization is identified as a significant predictor of NSSI behavior.Although prior research has explored the association between peer victimization and NSSI,the mechanisms underlying this relationship remain insufficiently understood.Utilizing social information processing theory frameworks,the present study seeks to examine the sequential mediating roles of a cognitive factor,future orientation,and a behavioral factor,social withdrawal,in middle school students.Methods:A cross-sectional survey was administered in China,involving 528 participants(261 females and 267 males;Meanage=13.71,standard deviation[SD]=0.93).Participants completed self-report measures assessing peer victimization via the Delaware Bullying Victimization Scale-Student Version,NSSI via the Adolescents Self-Harm Scale,future orientation via the Adolescent Future Orientation Questionnaire,and social withdrawal via the Social Withdrawal Questionnaire.Results:Findings indicated a significant positive correlation between peer victimization and NSSI(r=0.30,p<0.01).Additionally,future orientation and social withdrawal functioned as serial mediators,with an indirect effect of 0.01(95%CI:[0.01,0.02]),representing 2.70%of the total effect(𝛽=0.37,95%CI:[0.25,0.47]).Conclusions:The findings endorse a theoretical framework in which negative future outlook and social withdrawal are sequentially linked within the relationship between peer victimization and NSSI.Although the serial indirect effect observed is modest,it delineates a distinct associative pattern that characterizes adolescents subjected to victimization.These results carry practical significance for school-based intervention programs,indicating that targeting future perspectives and social connections may enhance strategies for preventing NSSI.展开更多
The effects of initial spin orientation on the final electron beam polarization in laser wakefield acceleration in a pre-polarized plasma are investigated theoretically and numerically.From the results of variation of...The effects of initial spin orientation on the final electron beam polarization in laser wakefield acceleration in a pre-polarized plasma are investigated theoretically and numerically.From the results of variation of the initial spin direction,the spin dynamics of the electron beam are found to depend on the self-injection mechanism.The effects of wakefields and laser fields are studied using test particle dynamics and particle-in-cell simulations based on the Thomas-Bargmann-Michel-Telegdi equation.Compared with transverse injection,longitudinal injection is found to be preferable for obtaining a highly polarized electron beam.展开更多
Determining the orientation of in-situ stresses is crucial for various geoscience and engineering appli-cations.Conventional methods for estimating these stress orientations often depend on focal mechanism solutions(F...Determining the orientation of in-situ stresses is crucial for various geoscience and engineering appli-cations.Conventional methods for estimating these stress orientations often depend on focal mechanism solutions(FMSs)derived from earthquake data and formation micro-imager(FMI)data from well logs.However,these techniques can be costly,depth-inaccurate,and may lack spatial coverage.To address this issue,we introduce the use of three-dimensional(3D)seismic data(active sources)as a lateral constraint to approximate the 3D stress orientation field.Recognizing that both stress and fracture patterns are closely related to seismic velocity anisotropy,we derive the orientation of azimuthal anisotropy from multi-azimuth 3D seismic data to compensate for the lack of spatial stress orientation information.We apply our proposed workflow to a case study in the Weiyuan area of the Sichuan Basin,China,a region targeted for shale gas production.By integrating diverse datasets,including 3D seismic,earthquakes,and well logs,we develop a comprehensive 3D model of in-situ stress(orientations and magnitudes).Our results demonstrate that the estimated anisotropy orientations from 3D seismic data are consistent with the direction of maximum horizontal principal stress(SHmax)obtained from FMIs.We analyzed 12 earthquakes(magnitude>3)recorded between 2016 and 2020 for their FMSs and compressional axis(P-axis)orientations.The derived SHmax direction from our 3D stress model is 110°ES(East-South),which shows excellent agreement with the FMSs(within 3.96°).This close alignment validates the reliability and precision of our integrated method for predicting 3D SHmax orientations.展开更多
Fracture(fault)reactivation can lead to dynamic geological hazards including earthquakes,rock collapses,landslides,and rock bursts.True triaxial compression tests were conducted to analyze the fracture reactivation pr...Fracture(fault)reactivation can lead to dynamic geological hazards including earthquakes,rock collapses,landslides,and rock bursts.True triaxial compression tests were conducted to analyze the fracture reactivation process under two different orientations of σ_(2),i.e.σ_(2) parallel to the fracture plane(Scheme 2)and σ_(2) cutting through the fracture plane(Scheme 3),under varying σ_(3) from 10 MPa to 40 MPa.The peak or fracture reactivation strength,deformation,failure mode,and post-peak mechanical behavior of intact(Scheme 1)and pre-fractured(Schemes 2 and 3)specimens were also compared.Results show that for intact specimens,the stress remains nearly constant in the residual sliding stage with no stick-slip,and the newly formed fracture surface only propagates along the σ_(2) direction when σ_(3) ranges from 10 MPa to 30 MPa,while it extends along both σ_(2) and σ_(3) directions when σ_(3) increases to 40 MPa;for the pre-fractured specimens,the fractures are usually reactivated under all the σ_(3) levels in Scheme 2,but fracture reactivation only occurs when σ_(3) is greater than 25 MPa in Scheme 3,below which new faulting traversing the original macro fracture occurs.In all the test schemes,both ε_(2) and ε_(3) experience an accumulative process of elongation,after which an abrupt change occurs at the point of the final failure;the degree of this change is dependent on the orientation of the new faulting or the slip direction of the original fracture,and it is generally more than 10 times larger in the slip direction of the original fracture than in the non-slip direction.Besides,the differential stress(peak stress)required for reactivation and the post-peak stress drop increase with increasing σ_(3).Post-peak stress drop and residual strength in Scheme 3 are generally greater than those in Scheme 2 at the same σ_(3) value.Our study clearly shows that intermediate principal stress orientation not only affects the fracture reactivation strength but also influences the slip deformation and failure modes.These new findings facilitate the mitigation of dynamic geological hazards associated with fracture and fault slip.展开更多
The prediction of the fracture plane orientation in fatigue is a scientific topic and remains relevant for every type of material. However, in this work, we compared the orientation of the fracture plane obtained expe...The prediction of the fracture plane orientation in fatigue is a scientific topic and remains relevant for every type of material. However, in this work, we compared the orientation of the fracture plane obtained experimentally through tests on specimens under multiaxial loading with that calculated by the variance method. In the statistical approach criteria, several methods have been developed but we have presented only one method, namely the variance method using the equivalent stress. She assumes that the fracture plane orientation is the one on which the variance of the equivalent stress is maximum. Three types of equivalent stress are defined for this method [1]: normal stress, shear stress and combined normal and shear stress. The results obtained were compared with experimental results for multiaxial cyclic stress states, and it emerges that the variance method for the case of combined loading is conservative as it gives a better prediction of the fracture plane.展开更多
The estimation of orientation parameters and correction of lens distortion are crucial problems in the field of Unmanned Aerial Vehicles(UAVs)photogrammetry.In recent years,the utilization of UAVs for aerial photogram...The estimation of orientation parameters and correction of lens distortion are crucial problems in the field of Unmanned Aerial Vehicles(UAVs)photogrammetry.In recent years,the utilization of UAVs for aerial photogrammetry has witnessed a surge in popularity.Typically,UAVs are equipped with low-cost non-metric cameras and a Position and Orientation System(POS).Unfortunately,the Interior Orientation Parameters(IOPs)of the non-metric cameras are not fixed.Whether the lens distortions are large or small,they effect the image coordinates accordingly.Additionally,Inertial Measurement Units(IMUs)often have observation errors.To address these challenges and improve parameter estimation for UAVs Light Detection and Ranging(LiDAR)and photogrammetry,this paper analyzes the accuracy of POS observations obtained from Global Navigation Satellite System Real Time Kinematic(GNSS-RTK)and IMU data.A method that incorporates additional known conditions for parameter estimation,a series of algorithms to simultaneously solve for IOPs,Exterior Orientation Parameters(EOPs),and camera lens distortion correction parameters are proposed.Extensive experiments demonstrate that the coordinates measured by GNSS-RTK can be directly used as linear EOPs;however,angular EOP measurements from IMUs exhibit relatively large errors compared to adjustment results and require correction during the adjustment process.The IOPs of non-metric cameras vary slightly between images but need to be treated as unknown parameters in high precision applications.Furthermore,it is found that the Ebner systematic error model is sensitive to the choice of the magnification parameter of the photographic baseline length in images,it should be set as less than or equal to one third of the photographic baseline to ensure stable solutions.展开更多
This paper discusses the key significance of college students’career planning and development in China,focusing on analyzing the role orientation of counselors and their functions in this process.Combined with the co...This paper discusses the key significance of college students’career planning and development in China,focusing on analyzing the role orientation of counselors and their functions in this process.Combined with the core content of career planning,the study explores how counselors can assist students’career development through various approaches,including awakening career awareness,enhancing self-cognition,and promoting career exploration.The specific implementation paths cover classroom teaching,thematic training,second classroom activities,the construction of“one-stop”student communities,and personalized heart-to-heart talks,so as to give full play to the role of counselors in career guidance.展开更多
The origin of the misorientations after fcc(face-centered cubic)to hcp(hexagonal close-packed)transformation in pure cobalt was elucidated by utilizing the electron backscatter diffraction(EBSD)technique and transform...The origin of the misorientations after fcc(face-centered cubic)to hcp(hexagonal close-packed)transformation in pure cobalt was elucidated by utilizing the electron backscatter diffraction(EBSD)technique and transformation crystallographic models.It is found the Shoji−Nishiyama orientation relationship during fcc→hcp transformation leads to four hcp variants,characterized by a common misorientation angle of 70.5°with respect to the<1120>direction,which is the predominant misorientation observed.Other statistically significant misorientation angles between hcp grains,including 32°,36°,38°,60°,71°and 86°−91°,are also identified.These newly observed misorientation angles are linked to the microstructure of the fcc matrix at elevated temperatures,with twin structures in the fcc matrix being the primary cause.Furthermore,a novel method is proposed for estimating the fraction of twins in the fcc grains based on misorientation angles between hcp variants,which is found to be consistent with experimental observations.In-situ EBSD observations validate the possible origin of fcc twins from the hcp→fcc transformation.展开更多
The performance of organic solar cells is significantly influenced by the acceptor molecular packing properties within the active layers,which is essential for optimizing charge dynamics and photovoltaic performance.H...The performance of organic solar cells is significantly influenced by the acceptor molecular packing properties within the active layers,which is essential for optimizing charge dynamics and photovoltaic performance.However,achieving precise control over this packaging structure presents a considerable challenge.Herein,we propose a dual additive strategy utilizing dibenzofuran and halogenated naphthalene to systematically manipulate molecular packing orientation and enhance the long-range molecular packing order of the acceptors.Dibenzofuran is crucial in promoting crystallinity within the material,facilitating the formation of an ordered structure,while halogenated naphthalene regulates the orientation of the molecules,ensuring proper alignment.Specifically,the combination of dibenzofuran and 1-chloronaphthalene promotes edge-on molecular packing and enhances the formation of nanofibrillar structures with improved order,leading to improved charge transport and device performance.Implementing this strategy in devices composed of PM6 and L8-BO has yielded a power conversion efficiency of 19.58%,accompanied by long-term stability.Similarly,1-fluoronaphthalene has also demonstrated effectiveness in improving molecular orientation and overall device efficiency,demonstrating the robustness of this dual additive strategy.By addressing the challenges associated with molecular packing and orientation in active layers,our result contributes valuable insights into optimizing organic solar cells for practical applications.展开更多
Secondary dendrite orientation and wall thickness considerably affect the stress rupture life of thin-walled samples.However,the effect of the secondary dendrite orientation on the thickness debit effect of nickel-bas...Secondary dendrite orientation and wall thickness considerably affect the stress rupture life of thin-walled samples.However,the effect of the secondary dendrite orientation on the thickness debit effect of nickel-based single-crystal superalloys has not been thoroughly investigated until now.Owing to geometrical constraints,typical sheet samples cannot reveal the mechanism responsible for the thickness debit effect in turbine blades.This study examined the effect of secondary dendrite orientation on the thickness debit effect of nickel-based single-crystal superalloys at 1100℃/137 MPa in tubular samples.As the wall thickness decreased from 1.5 mm to 0.3 mm,the stress rupture life decreased from approximately 170 h to 64 h,demonstrating a noticeable thickness debit effect.Among the different secondary dendrite orientation areas,the variation in plastic deformation difference increased from 7%(1.5 mm)to 45%(0.5 mm)and subsequently decreased to 4%(0.3 mm).In thinner samples,the thickness contraction and microstructure evolution were more pronounced in the[100]areas than that in the[110]and[210]areas.The theoretical calculation quantitatively indicated that for the effective stress increased,the contribution of plastic deformation(45%)was slightly lower than that of oxidation(55%)in 0.3 mm samples;nevertheless,plastic deformation played a prominent role in 0.5,0.8,1,and 1.5 mm samples and increased from 61%(0.5 mm samples)to 85%(1.5 mm samples).In thinner samples,the larger plastic deformation in the secondary dendrite orientation of the[100]areas and oxidation increased the effective stress,resulting in a shorter rupture life.These findings are conducive to the structural optimization and performance improvement of turbine blades.展开更多
This paper presents a systematic comparison of the curriculum design and application orientation of the linear algebra curriculum in our country and abroad.It explains mainly differences in course objectives,teaching ...This paper presents a systematic comparison of the curriculum design and application orientation of the linear algebra curriculum in our country and abroad.It explains mainly differences in course objectives,teaching content,approaches,and feedback mechanisms,reflecting divergent understandings of the discipline’s value within distinct educational ecosystems.Forward-looking and practical conclusions are proposed across five main directions:optimizing course structure,strengthening practical components,deepening interdisciplinary integration,building faculty capacity,and developing teaching resources.The aim is to provide strong conceptual help and realistic guidance for getting real progress in linear algebra education in China.展开更多
Bismuth oxybromide(BiOBr)is being actively researched as a promising anode material for aqueous batteries due to its unique layered structure,which theoretically allows for efficient ion diffusion.However,current stud...Bismuth oxybromide(BiOBr)is being actively researched as a promising anode material for aqueous batteries due to its unique layered structure,which theoretically allows for efficient ion diffusion.However,current studies have come across many challenges,e.g.serious capacity degradation and inferior rate capability caused by severe structural collapse and sluggish reaction kinetics,highlighting the need for further improvement in efficient utilization of the layered space.Herein,this study employs a novel crystal orientation regulation to enhance the performance of BiOBr electrode by a facile solvothermal method to efficiently utilize the interlayered structu re.The delicate design of BiOBr(BOB)succeeds in maximizing the exposed(110)crystalline plane,providing efficient pathways for ion diffusion and streamlining the mass migration process.Moreover,the optimized band structure and the formation of oxygen vacancies in this designed material have been found,enabling high electrical conductivity,accelerating the charge transfer process and facilitating rapid reaction rate.Owing to the simultaneously enhanced mass transfer at the interlayers and the charge transfer during the phase conversion process,the BOB-110 electrode exhibits exceptional electrochemical performances,boasting impressive charge storage and rate capability(159 mAh g^(-1)at 4 A g^(-1)),and outstanding cycling stability of capacity retention around 75%(119 mAh g^(-1))even after 1000 cycles at a high current density of 4 A g^(-1).These findings underscore the substantial potential of BiOBr electrodes for future energy storage devices such as wearable electronics and power grids where the power output,lifespan,and affordability are simultaneously required.展开更多
A novel Additive Manufacturing(AM)-driven concurrent design strategy based on the beam characterization model considering strength constraints is proposed.The lattice topology,radius size,Building Orientation(BO),and ...A novel Additive Manufacturing(AM)-driven concurrent design strategy based on the beam characterization model considering strength constraints is proposed.The lattice topology,radius size,Building Orientation(BO),and structural yield strength can be simultaneously adjusted by integrating the overall process-structure-performance relationship of the AM process into the optimization.Specifically,the transverse isotropic material model is adopted to describe the material properties induced by the layer-by-layer manner of additive manufacturing.To bolster lattice strength performance,the stress constraints and ratio constraints of lattice struts are employed.The Tsai-Wu yield criterion is implemented to characterize the lattice strut's strength,while the P-norm method streamlines the handling of multiple constraints,minimizing computational overhead.Moreover,the gradient-based optimization model is established,where both the individual struts diameters and BO can be designed,and the buckling-prone spatial struts are strategically eliminated to improve the lattice strength further.Furthermore,several typical structures are optimized to verify the effectiveness of the proposed method.The optimized results are quite encouraging since the heterogeneous lattice structures with optimized BO obtained by the strength-based concurrent method show a remarkably improved performance compared to traditional designs.展开更多
Carbon fiber reinforced polymer(CFRP)composites,as a typical difficult-to-machine material,exhibit high cutting forces and temperatures during actual machining,leading to more severe tool wear compared to traditional ...Carbon fiber reinforced polymer(CFRP)composites,as a typical difficult-to-machine material,exhibit high cutting forces and temperatures during actual machining,leading to more severe tool wear compared to traditional metal ma-terials.The shear fracture during fiber cutting is incomplete,resulting in surface defects such as unclosed fibers and burrs.To analyze the cutting forces and tool wear areas when cutting CFRP with different fiber angles,a three-dimensional or-thogonal cutting model of CFRP was established using finite element software and the VUMAT subroutine,based on the three-dimensional Hashin criterion.Simulation results show that during the cutting process of CFRP,high-stress areas appear in the region where the cutting edge contacts the workpiece for each fiber orientation,primarily concentrated in the first deformation zone in contact with the cutting edge.The Mises stress is highest when cutting the 90°fibers and lowest when cutting the 0°fibers.When cutting the 0°and 135°fibers,the tool is prone to wear on both the rake and flank faces,while when cutting the 45°and 90°fibers,the tool's rake face is more likely to experience wear.展开更多
The rapid advancement of the bioeconomy imposes increasingly stringent demands on bioengineering education.Drawing on data from the 2025 Chinese Undergraduate Employment Report and related sources,this study revealed ...The rapid advancement of the bioeconomy imposes increasingly stringent demands on bioengineering education.Drawing on data from the 2025 Chinese Undergraduate Employment Report and related sources,this study revealed that while employment placement rates for bioengineering graduates remain stable,starting salaries exhibit limited growth and career trajectories lack clarity.These challenges originate from a curriculum lagging behind technological progress,inadequate practical training,and a mismatch between student competencies and industry expectations.To address these issues,this paper proposed a strategic framework grounded in"demand-driven design,industry-education integration,and competence-centered development".Key strategies include dynamic curriculum renewal,collaborative university-industry training,holistic competency development,and personalized student support,which collectively aim at enhancing graduates employment competitiveness and long-term professional sustainability.展开更多
In the wave of internet culture,short videos have become an indispensable medium for social communication.The metaphorical hot words contained within them serve as a unique linguistic phenomenon that leads topics and ...In the wave of internet culture,short videos have become an indispensable medium for social communication.The metaphorical hot words contained within them serve as a unique linguistic phenomenon that leads topics and focuses attention,greatly enriching the expressive layers and rhetorical charm of short videos,and significantly enhancing the video’s theme orientation and emotional identification.This research aims to explore the relationship between the use of metaphorical Internet buzzwords in short videos and the thematic and emotional orientation.The study adopts a combination of qualitative and quantitative methods,taking 10 videos with over 10,000 likes posted by a well-known blogger on Xiaohongshu in 2024 as the research object,transcribing the text,forming research corpora,and conducting multi-dimensional cognitive analysis on them.The study shows that about half of short videos contain metaphorical hot words.Different types of metaphorical hot words can trigger different emotional reactions from fans,especially humorous metaphorical hot words that can stimulate fans’emotional identification and resonance.In addition,in terms of fan participation,videos using metaphorical hot words tend to attract more fan attention than those that do not:these videos not only attract more fans to watch and like,but also trigger more comments and sharing behaviors.In summary,short videos cleverly use metaphors to create internet hot words,significantly enhancing the video’s thematic guidance and emotional resonance,manifested in creating popular topics,clarifying guiding themes,enhancing content attractiveness,and stimulating strong emotional identification,thereby promoting interactive behaviors such as likes and shares.These findings provide a reference for research in related fields such as metaphor,communication studies,and sociology.展开更多
The orientations of ancient tombs have attracted increasing scholarly attention,as they offer valuable insights into early social structures,cultural traditions,and the relationship between humans and their environmen...The orientations of ancient tombs have attracted increasing scholarly attention,as they offer valuable insights into early social structures,cultural traditions,and the relationship between humans and their environment.However,the application of machine learning algorithms to the study of tomb orientation remains relatively underexplored.In this study,we employed a Gaussian mixture model to conduct a systematic analysis of the spatial and temporal evolution of Neolithic tomb orientations in Central China.We also examined the relationship between tomb orientation and both environmental factors and sociocultural dynamics.The findings suggest a deliberate and methodical approach to the planning and alignment of tombs during the Neolithic Age.Tomb orientations in each chronological phase displayed clear clustering patterns,reflecting a developmental trajectory from uniformity to diversity,and ultimately toward integration.While early angular measurement techniques appear to have emerged,they do not show evidence of sustained technical progression.Instead,different periods seem to have achieved similar levels of directional accuracy.The predominance of westward-facing tombs may be closely tied to both topographic features and the symbolic association with sunset.At the same time,cultural evolution and interregional exchange played essential roles in shaping the distinctive patterns of prehistoric tomb orientation.This research contributes not only to the understanding of ancient funerary practices but also demonstrates the potential of machine learning and artificial intelligence technologies in advancing archaeological analysis.展开更多
Doped HfO_(2)as an emerging ferroelectric material,holds considerable promise for non-volatile memory applications.Epitaxial growth of doped HfO_(2)thin films is widely adopted as an effective technique for revealing ...Doped HfO_(2)as an emerging ferroelectric material,holds considerable promise for non-volatile memory applications.Epitaxial growth of doped HfO_(2)thin films is widely adopted as an effective technique for revealing the intrinsic ferroelectric properties.In this study,based on systematic structural,chemical and electrical investigations,the influences of Mn doping and substrate orientation on ferroelectric properties of Mn-doped HfO_(2)epitaxial thin films are investigated.The results demonstrate that Mn-doped HfO_(2)thin films with orthorhombic phase can be epitaxially grown along[111]out-of-plane direction on both SrTiO_(3)(001)and(110)substrates,and 10%Mn-doping significantly stabilizes the orthorhombic polar phase and enhances the ferroelectric polarization.Interestingly,compared to the films on SrTiO_(3)(001)substrate,the better crystallinity and reduction of oxygen vacancy amount in Mn-doped HfO_(2)films grown on the SrTiO_(3)(110)substrate are observed,which enhance the remanent polarization and reduce the coercive field.It provides an effective approach for the controllable regulation of defects and the enhancement of intrinsic ferroelectricity in HfO_(2)-based materials.展开更多
The design and development of high-performance anodes pose significant challenges in the construction of next-generation rechargeable lithium-ion batteries(LIBs).Sodium molybdate dihydrate(Na_(2)MoO_(4)·2H_(2)O)h...The design and development of high-performance anodes pose significant challenges in the construction of next-generation rechargeable lithium-ion batteries(LIBs).Sodium molybdate dihydrate(Na_(2)MoO_(4)·2H_(2)O)has garnered increasing attention due to its cost-effectiveness,non-toxicity and earth abundance.To enhance the Li storage performance of Na_(2)MoO_(4)·2H_(2)O,a crystallographic orientation regulation strategy is proposed in this work.Initially,density functional theory calculations are carried out to demonstrate that the(020)crystal plane of Na_(2)MoO_(4)·2H_(2)O offers the lowest energy barrier for Li^(+)migration.Subsequently,the preferred crystallographic orientation of Na_(2)MoO_(4)·2H_(2)O crystal is tuned through a low-temperature recrystallization method.Furthermore,the microstructure and phase changes of Na_(2)MoO_(4)·2H_(2)O during the lithiation/de-lithiation process are studied using in situ and ex situ XRD tests,ex situ XPS and cyclic voltammetry to unravel its Li^(+)storage mechanism.Upon application as LIBs anode,the Na_(2)MoO_(4)·2H_(2)O single-crystal particles with a preferred(020)surface exhibit superior reversible capacity,high-capacity retention and high cycling stability.The enhanced Li storage performance should be attributed to the regulated crystallographic orientation and small changes in the crystal microstructure during the charge/discharge process,which facilitates Li^(+)migration and bolsters structural stability.Notably,this study introduces a novel concept and a simple synthesis method for the advancement of electrodes in rechargeable batteries.展开更多
基金supported by the Natural Science Foundation of Anhui Province in China(2508085MF166)Research Fund of Anhui Institute of Translational Medicine(2024zh-03)+2 种基金Key Scientific Research Foundation of Education Department of Anhui Province(2023AH040083)National Natural Science Foundation of China(12404353)Cultivation Project of Training Young and Middle-aged Teachers in Universities of Anhui Province(DTR2023013).
文摘Optical tweezers technology has the characteristics of noncontact manipulation in three dimensions and steerable separation in solutions,and could be applied to obtain a separated sperm with high quality for intracytoplasmic sperm injection(ICSI).However,the effects of optical tweezers on sperm motility are still unclear.To elucidate the effects on sperm motility for optical tweezers,we systematically investigated the correlation between motility parameters and the parameters of optical tweezers(wavelength,power,trapping duration,and trapping orientation).Under three systems of optical tweezers with different laser wavelengths(1064,850,and 785 nm),the nine motility parameters of free swimming were mainly affected by trapping orientation(vertical/horizontal)and trapping duration.When 850 nm laser and 1064 nm laser are used,vertical trapping significantly reduces sperm free-swimming capability with prolonged exposure time,whereas horizontal trapping exhibits relatively minor interference on sperm motility.Notably,the 785 nm laser does not induce statistically significant changes in key parameters of sperm motility under any experimental conditions(trapping orientation and duration).For the rolling frequency of trapped sperm,horizontal trapping for three wavelengths has a negligible effect compared with vertical trapping,especially for the 785 nm laser.In conclusion,horizontal trapping can preserve sperm motility under low power(below 140mW at 1064 nm,below 100mW at 850nm,below 60mW at 785 nm)and short duration(below 4 min).This trapping duration is suffcient for the separation procedure of single live sperm in ICSI.This study provides critical parameter optimization guidelines for the safe application of optical tweezers technology in reproductive medicine.
基金supported by 2024 The Basic Ability Improvement Project for Young and Middle-aged Teachers of Colleges and Universities in Guangxi(No.2024KY0165)2024 Guangxi Minzu University General Research Project(Humanities and Social Sciences Category,No.2024MDSKYB20)2022 Annual Teaching and Research Project of Shiyuan College of Nanning Normal University(No.2022JY13).
文摘Objectives:Non-suicidal self-injury(NSSI)represents a prominent and escalating concern within mental health,associated with considerable psychological and physical dangers.Peer victimization is identified as a significant predictor of NSSI behavior.Although prior research has explored the association between peer victimization and NSSI,the mechanisms underlying this relationship remain insufficiently understood.Utilizing social information processing theory frameworks,the present study seeks to examine the sequential mediating roles of a cognitive factor,future orientation,and a behavioral factor,social withdrawal,in middle school students.Methods:A cross-sectional survey was administered in China,involving 528 participants(261 females and 267 males;Meanage=13.71,standard deviation[SD]=0.93).Participants completed self-report measures assessing peer victimization via the Delaware Bullying Victimization Scale-Student Version,NSSI via the Adolescents Self-Harm Scale,future orientation via the Adolescent Future Orientation Questionnaire,and social withdrawal via the Social Withdrawal Questionnaire.Results:Findings indicated a significant positive correlation between peer victimization and NSSI(r=0.30,p<0.01).Additionally,future orientation and social withdrawal functioned as serial mediators,with an indirect effect of 0.01(95%CI:[0.01,0.02]),representing 2.70%of the total effect(𝛽=0.37,95%CI:[0.25,0.47]).Conclusions:The findings endorse a theoretical framework in which negative future outlook and social withdrawal are sequentially linked within the relationship between peer victimization and NSSI.Although the serial indirect effect observed is modest,it delineates a distinct associative pattern that characterizes adolescents subjected to victimization.These results carry practical significance for school-based intervention programs,indicating that targeting future perspectives and social connections may enhance strategies for preventing NSSI.
基金supported by the National Natural Science Foundation of China(Grant Nos.11804348,11775056,11975154,12225505,and 12405281)the Science Challenge(Project No.TZ2018005)+2 种基金supported by the Shanghai Pujiang Program(Grant No.23PJ1414600)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB0890203)supported by the Accelerator Technology Helmholtz Infrastructure consortium ATHENA.
文摘The effects of initial spin orientation on the final electron beam polarization in laser wakefield acceleration in a pre-polarized plasma are investigated theoretically and numerically.From the results of variation of the initial spin direction,the spin dynamics of the electron beam are found to depend on the self-injection mechanism.The effects of wakefields and laser fields are studied using test particle dynamics and particle-in-cell simulations based on the Thomas-Bargmann-Michel-Telegdi equation.Compared with transverse injection,longitudinal injection is found to be preferable for obtaining a highly polarized electron beam.
基金supported by the National Key R&D Program of China(Grant No.2020YFA0710604)NSFC(Grant No.42374064).
文摘Determining the orientation of in-situ stresses is crucial for various geoscience and engineering appli-cations.Conventional methods for estimating these stress orientations often depend on focal mechanism solutions(FMSs)derived from earthquake data and formation micro-imager(FMI)data from well logs.However,these techniques can be costly,depth-inaccurate,and may lack spatial coverage.To address this issue,we introduce the use of three-dimensional(3D)seismic data(active sources)as a lateral constraint to approximate the 3D stress orientation field.Recognizing that both stress and fracture patterns are closely related to seismic velocity anisotropy,we derive the orientation of azimuthal anisotropy from multi-azimuth 3D seismic data to compensate for the lack of spatial stress orientation information.We apply our proposed workflow to a case study in the Weiyuan area of the Sichuan Basin,China,a region targeted for shale gas production.By integrating diverse datasets,including 3D seismic,earthquakes,and well logs,we develop a comprehensive 3D model of in-situ stress(orientations and magnitudes).Our results demonstrate that the estimated anisotropy orientations from 3D seismic data are consistent with the direction of maximum horizontal principal stress(SHmax)obtained from FMIs.We analyzed 12 earthquakes(magnitude>3)recorded between 2016 and 2020 for their FMSs and compressional axis(P-axis)orientations.The derived SHmax direction from our 3D stress model is 110°ES(East-South),which shows excellent agreement with the FMSs(within 3.96°).This close alignment validates the reliability and precision of our integrated method for predicting 3D SHmax orientations.
基金funding support from the National Nature Science Foundation of China(Grant No.42272334)the National Key Research and Development Program of China(Grant No.2022YFE0137200)the Taishan Scholars Program(Grant No.2019RKB01083).
文摘Fracture(fault)reactivation can lead to dynamic geological hazards including earthquakes,rock collapses,landslides,and rock bursts.True triaxial compression tests were conducted to analyze the fracture reactivation process under two different orientations of σ_(2),i.e.σ_(2) parallel to the fracture plane(Scheme 2)and σ_(2) cutting through the fracture plane(Scheme 3),under varying σ_(3) from 10 MPa to 40 MPa.The peak or fracture reactivation strength,deformation,failure mode,and post-peak mechanical behavior of intact(Scheme 1)and pre-fractured(Schemes 2 and 3)specimens were also compared.Results show that for intact specimens,the stress remains nearly constant in the residual sliding stage with no stick-slip,and the newly formed fracture surface only propagates along the σ_(2) direction when σ_(3) ranges from 10 MPa to 30 MPa,while it extends along both σ_(2) and σ_(3) directions when σ_(3) increases to 40 MPa;for the pre-fractured specimens,the fractures are usually reactivated under all the σ_(3) levels in Scheme 2,but fracture reactivation only occurs when σ_(3) is greater than 25 MPa in Scheme 3,below which new faulting traversing the original macro fracture occurs.In all the test schemes,both ε_(2) and ε_(3) experience an accumulative process of elongation,after which an abrupt change occurs at the point of the final failure;the degree of this change is dependent on the orientation of the new faulting or the slip direction of the original fracture,and it is generally more than 10 times larger in the slip direction of the original fracture than in the non-slip direction.Besides,the differential stress(peak stress)required for reactivation and the post-peak stress drop increase with increasing σ_(3).Post-peak stress drop and residual strength in Scheme 3 are generally greater than those in Scheme 2 at the same σ_(3) value.Our study clearly shows that intermediate principal stress orientation not only affects the fracture reactivation strength but also influences the slip deformation and failure modes.These new findings facilitate the mitigation of dynamic geological hazards associated with fracture and fault slip.
文摘The prediction of the fracture plane orientation in fatigue is a scientific topic and remains relevant for every type of material. However, in this work, we compared the orientation of the fracture plane obtained experimentally through tests on specimens under multiaxial loading with that calculated by the variance method. In the statistical approach criteria, several methods have been developed but we have presented only one method, namely the variance method using the equivalent stress. She assumes that the fracture plane orientation is the one on which the variance of the equivalent stress is maximum. Three types of equivalent stress are defined for this method [1]: normal stress, shear stress and combined normal and shear stress. The results obtained were compared with experimental results for multiaxial cyclic stress states, and it emerges that the variance method for the case of combined loading is conservative as it gives a better prediction of the fracture plane.
基金Natural Science Foundation of Hunan Province,China(No.2024JJ8335)Open Topic of Hunan Geospatial Information Engineering and Technology Research Center,China(No.HNGIET2023004).
文摘The estimation of orientation parameters and correction of lens distortion are crucial problems in the field of Unmanned Aerial Vehicles(UAVs)photogrammetry.In recent years,the utilization of UAVs for aerial photogrammetry has witnessed a surge in popularity.Typically,UAVs are equipped with low-cost non-metric cameras and a Position and Orientation System(POS).Unfortunately,the Interior Orientation Parameters(IOPs)of the non-metric cameras are not fixed.Whether the lens distortions are large or small,they effect the image coordinates accordingly.Additionally,Inertial Measurement Units(IMUs)often have observation errors.To address these challenges and improve parameter estimation for UAVs Light Detection and Ranging(LiDAR)and photogrammetry,this paper analyzes the accuracy of POS observations obtained from Global Navigation Satellite System Real Time Kinematic(GNSS-RTK)and IMU data.A method that incorporates additional known conditions for parameter estimation,a series of algorithms to simultaneously solve for IOPs,Exterior Orientation Parameters(EOPs),and camera lens distortion correction parameters are proposed.Extensive experiments demonstrate that the coordinates measured by GNSS-RTK can be directly used as linear EOPs;however,angular EOP measurements from IMUs exhibit relatively large errors compared to adjustment results and require correction during the adjustment process.The IOPs of non-metric cameras vary slightly between images but need to be treated as unknown parameters in high precision applications.Furthermore,it is found that the Ebner systematic error model is sensitive to the choice of the magnification parameter of the photographic baseline length in images,it should be set as less than or equal to one third of the photographic baseline to ensure stable solutions.
文摘This paper discusses the key significance of college students’career planning and development in China,focusing on analyzing the role orientation of counselors and their functions in this process.Combined with the core content of career planning,the study explores how counselors can assist students’career development through various approaches,including awakening career awareness,enhancing self-cognition,and promoting career exploration.The specific implementation paths cover classroom teaching,thematic training,second classroom activities,the construction of“one-stop”student communities,and personalized heart-to-heart talks,so as to give full play to the role of counselors in career guidance.
基金supported by the National Key R&D Program of China(No.2022YFB3504403).
文摘The origin of the misorientations after fcc(face-centered cubic)to hcp(hexagonal close-packed)transformation in pure cobalt was elucidated by utilizing the electron backscatter diffraction(EBSD)technique and transformation crystallographic models.It is found the Shoji−Nishiyama orientation relationship during fcc→hcp transformation leads to four hcp variants,characterized by a common misorientation angle of 70.5°with respect to the<1120>direction,which is the predominant misorientation observed.Other statistically significant misorientation angles between hcp grains,including 32°,36°,38°,60°,71°and 86°−91°,are also identified.These newly observed misorientation angles are linked to the microstructure of the fcc matrix at elevated temperatures,with twin structures in the fcc matrix being the primary cause.Furthermore,a novel method is proposed for estimating the fraction of twins in the fcc grains based on misorientation angles between hcp variants,which is found to be consistent with experimental observations.In-situ EBSD observations validate the possible origin of fcc twins from the hcp→fcc transformation.
基金the financial support from the National Natural Science Foundation of China(62275057)the Guangxi Natural Science Foundation(2023GXNSFFA026004)+2 种基金the Guangxi Talent Program("Highland of Innovation Talents")the Shenzhen High-tech Development Special Plan-Pingshan Districts Innovation Platform Project(29853M-KCJ-2023-002-04)Industry and Energy(MOTIE),Republic of Korea(Project No.:RS-2025-02413058)。
文摘The performance of organic solar cells is significantly influenced by the acceptor molecular packing properties within the active layers,which is essential for optimizing charge dynamics and photovoltaic performance.However,achieving precise control over this packaging structure presents a considerable challenge.Herein,we propose a dual additive strategy utilizing dibenzofuran and halogenated naphthalene to systematically manipulate molecular packing orientation and enhance the long-range molecular packing order of the acceptors.Dibenzofuran is crucial in promoting crystallinity within the material,facilitating the formation of an ordered structure,while halogenated naphthalene regulates the orientation of the molecules,ensuring proper alignment.Specifically,the combination of dibenzofuran and 1-chloronaphthalene promotes edge-on molecular packing and enhances the formation of nanofibrillar structures with improved order,leading to improved charge transport and device performance.Implementing this strategy in devices composed of PM6 and L8-BO has yielded a power conversion efficiency of 19.58%,accompanied by long-term stability.Similarly,1-fluoronaphthalene has also demonstrated effectiveness in improving molecular orientation and overall device efficiency,demonstrating the robustness of this dual additive strategy.By addressing the challenges associated with molecular packing and orientation in active layers,our result contributes valuable insights into optimizing organic solar cells for practical applications.
基金financially supported by the Science Center for Gas Turbine Project(No.P2021-AB-Ⅳ-001-002).
文摘Secondary dendrite orientation and wall thickness considerably affect the stress rupture life of thin-walled samples.However,the effect of the secondary dendrite orientation on the thickness debit effect of nickel-based single-crystal superalloys has not been thoroughly investigated until now.Owing to geometrical constraints,typical sheet samples cannot reveal the mechanism responsible for the thickness debit effect in turbine blades.This study examined the effect of secondary dendrite orientation on the thickness debit effect of nickel-based single-crystal superalloys at 1100℃/137 MPa in tubular samples.As the wall thickness decreased from 1.5 mm to 0.3 mm,the stress rupture life decreased from approximately 170 h to 64 h,demonstrating a noticeable thickness debit effect.Among the different secondary dendrite orientation areas,the variation in plastic deformation difference increased from 7%(1.5 mm)to 45%(0.5 mm)and subsequently decreased to 4%(0.3 mm).In thinner samples,the thickness contraction and microstructure evolution were more pronounced in the[100]areas than that in the[110]and[210]areas.The theoretical calculation quantitatively indicated that for the effective stress increased,the contribution of plastic deformation(45%)was slightly lower than that of oxidation(55%)in 0.3 mm samples;nevertheless,plastic deformation played a prominent role in 0.5,0.8,1,and 1.5 mm samples and increased from 61%(0.5 mm samples)to 85%(1.5 mm samples).In thinner samples,the larger plastic deformation in the secondary dendrite orientation of the[100]areas and oxidation increased the effective stress,resulting in a shorter rupture life.These findings are conducive to the structural optimization and performance improvement of turbine blades.
文摘This paper presents a systematic comparison of the curriculum design and application orientation of the linear algebra curriculum in our country and abroad.It explains mainly differences in course objectives,teaching content,approaches,and feedback mechanisms,reflecting divergent understandings of the discipline’s value within distinct educational ecosystems.Forward-looking and practical conclusions are proposed across five main directions:optimizing course structure,strengthening practical components,deepening interdisciplinary integration,building faculty capacity,and developing teaching resources.The aim is to provide strong conceptual help and realistic guidance for getting real progress in linear algebra education in China.
基金supported by the CRF grant of the Hong Kong Research Grant Council(C5031-20G)the Guang Dong Basic and Applied Basic Research Foundation(2024A1515013283)the Seed Fund of University Research Committee(2201100760)。
文摘Bismuth oxybromide(BiOBr)is being actively researched as a promising anode material for aqueous batteries due to its unique layered structure,which theoretically allows for efficient ion diffusion.However,current studies have come across many challenges,e.g.serious capacity degradation and inferior rate capability caused by severe structural collapse and sluggish reaction kinetics,highlighting the need for further improvement in efficient utilization of the layered space.Herein,this study employs a novel crystal orientation regulation to enhance the performance of BiOBr electrode by a facile solvothermal method to efficiently utilize the interlayered structu re.The delicate design of BiOBr(BOB)succeeds in maximizing the exposed(110)crystalline plane,providing efficient pathways for ion diffusion and streamlining the mass migration process.Moreover,the optimized band structure and the formation of oxygen vacancies in this designed material have been found,enabling high electrical conductivity,accelerating the charge transfer process and facilitating rapid reaction rate.Owing to the simultaneously enhanced mass transfer at the interlayers and the charge transfer during the phase conversion process,the BOB-110 electrode exhibits exceptional electrochemical performances,boasting impressive charge storage and rate capability(159 mAh g^(-1)at 4 A g^(-1)),and outstanding cycling stability of capacity retention around 75%(119 mAh g^(-1))even after 1000 cycles at a high current density of 4 A g^(-1).These findings underscore the substantial potential of BiOBr electrodes for future energy storage devices such as wearable electronics and power grids where the power output,lifespan,and affordability are simultaneously required.
基金co-supported by National Key R&D Program of China(No.2022YFB4602003)Key Project of National Natural Science Foundation of China(No.12032018)+2 种基金Guangdong Basic and Applied Basic Research Foundation(No.2022A1515110489)National Natural Science Foundation of China-China Academy of General Technology Joint Fund for Basic Research(No.52375380)National Key Research and Development Program of China(No.2022YFB3402200)。
文摘A novel Additive Manufacturing(AM)-driven concurrent design strategy based on the beam characterization model considering strength constraints is proposed.The lattice topology,radius size,Building Orientation(BO),and structural yield strength can be simultaneously adjusted by integrating the overall process-structure-performance relationship of the AM process into the optimization.Specifically,the transverse isotropic material model is adopted to describe the material properties induced by the layer-by-layer manner of additive manufacturing.To bolster lattice strength performance,the stress constraints and ratio constraints of lattice struts are employed.The Tsai-Wu yield criterion is implemented to characterize the lattice strut's strength,while the P-norm method streamlines the handling of multiple constraints,minimizing computational overhead.Moreover,the gradient-based optimization model is established,where both the individual struts diameters and BO can be designed,and the buckling-prone spatial struts are strategically eliminated to improve the lattice strength further.Furthermore,several typical structures are optimized to verify the effectiveness of the proposed method.The optimized results are quite encouraging since the heterogeneous lattice structures with optimized BO obtained by the strength-based concurrent method show a remarkably improved performance compared to traditional designs.
文摘Carbon fiber reinforced polymer(CFRP)composites,as a typical difficult-to-machine material,exhibit high cutting forces and temperatures during actual machining,leading to more severe tool wear compared to traditional metal ma-terials.The shear fracture during fiber cutting is incomplete,resulting in surface defects such as unclosed fibers and burrs.To analyze the cutting forces and tool wear areas when cutting CFRP with different fiber angles,a three-dimensional or-thogonal cutting model of CFRP was established using finite element software and the VUMAT subroutine,based on the three-dimensional Hashin criterion.Simulation results show that during the cutting process of CFRP,high-stress areas appear in the region where the cutting edge contacts the workpiece for each fiber orientation,primarily concentrated in the first deformation zone in contact with the cutting edge.The Mises stress is highest when cutting the 90°fibers and lowest when cutting the 0°fibers.When cutting the 0°and 135°fibers,the tool is prone to wear on both the rake and flank faces,while when cutting the 45°and 90°fibers,the tool's rake face is more likely to experience wear.
基金Supported by Undergraduate Education and Teaching Reform Research Project of Chengdu University(XJJG-20242025228)Sichuan Genuine Medicinal Materials and Traditional Chinese Medicine Innovation Team(SCCXTD-2025-19)Sichuan Science and Technology Program(2021YFYZ0012).
文摘The rapid advancement of the bioeconomy imposes increasingly stringent demands on bioengineering education.Drawing on data from the 2025 Chinese Undergraduate Employment Report and related sources,this study revealed that while employment placement rates for bioengineering graduates remain stable,starting salaries exhibit limited growth and career trajectories lack clarity.These challenges originate from a curriculum lagging behind technological progress,inadequate practical training,and a mismatch between student competencies and industry expectations.To address these issues,this paper proposed a strategic framework grounded in"demand-driven design,industry-education integration,and competence-centered development".Key strategies include dynamic curriculum renewal,collaborative university-industry training,holistic competency development,and personalized student support,which collectively aim at enhancing graduates employment competitiveness and long-term professional sustainability.
文摘In the wave of internet culture,short videos have become an indispensable medium for social communication.The metaphorical hot words contained within them serve as a unique linguistic phenomenon that leads topics and focuses attention,greatly enriching the expressive layers and rhetorical charm of short videos,and significantly enhancing the video’s theme orientation and emotional identification.This research aims to explore the relationship between the use of metaphorical Internet buzzwords in short videos and the thematic and emotional orientation.The study adopts a combination of qualitative and quantitative methods,taking 10 videos with over 10,000 likes posted by a well-known blogger on Xiaohongshu in 2024 as the research object,transcribing the text,forming research corpora,and conducting multi-dimensional cognitive analysis on them.The study shows that about half of short videos contain metaphorical hot words.Different types of metaphorical hot words can trigger different emotional reactions from fans,especially humorous metaphorical hot words that can stimulate fans’emotional identification and resonance.In addition,in terms of fan participation,videos using metaphorical hot words tend to attract more fan attention than those that do not:these videos not only attract more fans to watch and like,but also trigger more comments and sharing behaviors.In summary,short videos cleverly use metaphors to create internet hot words,significantly enhancing the video’s thematic guidance and emotional resonance,manifested in creating popular topics,clarifying guiding themes,enhancing content attractiveness,and stimulating strong emotional identification,thereby promoting interactive behaviors such as likes and shares.These findings provide a reference for research in related fields such as metaphor,communication studies,and sociology.
基金The Basic Scientific Research of Henan Academy of Sciences,No.20250601010National Natural Science Foundation of China,No.41971016+2 种基金The Innovation Team Project of Henan Academy of Sciences,No.20230103Science and Technology Innovation Platform Cultivation and Promotion Project of Henan Academy of Sciences,No.241001037The Soft Science Project of Henan Province,No.252400410524。
文摘The orientations of ancient tombs have attracted increasing scholarly attention,as they offer valuable insights into early social structures,cultural traditions,and the relationship between humans and their environment.However,the application of machine learning algorithms to the study of tomb orientation remains relatively underexplored.In this study,we employed a Gaussian mixture model to conduct a systematic analysis of the spatial and temporal evolution of Neolithic tomb orientations in Central China.We also examined the relationship between tomb orientation and both environmental factors and sociocultural dynamics.The findings suggest a deliberate and methodical approach to the planning and alignment of tombs during the Neolithic Age.Tomb orientations in each chronological phase displayed clear clustering patterns,reflecting a developmental trajectory from uniformity to diversity,and ultimately toward integration.While early angular measurement techniques appear to have emerged,they do not show evidence of sustained technical progression.Instead,different periods seem to have achieved similar levels of directional accuracy.The predominance of westward-facing tombs may be closely tied to both topographic features and the symbolic association with sunset.At the same time,cultural evolution and interregional exchange played essential roles in shaping the distinctive patterns of prehistoric tomb orientation.This research contributes not only to the understanding of ancient funerary practices but also demonstrates the potential of machine learning and artificial intelligence technologies in advancing archaeological analysis.
基金supported by the National Natural Science Foundation of China(Grant Nos.52125204,52250281,52422209,92163210,and U21A2066)the Na-tional Key Research and Development Program of China(Grant Nos.2024YFA1208601,2022YFB3807602,and 2022YFB3807604).
文摘Doped HfO_(2)as an emerging ferroelectric material,holds considerable promise for non-volatile memory applications.Epitaxial growth of doped HfO_(2)thin films is widely adopted as an effective technique for revealing the intrinsic ferroelectric properties.In this study,based on systematic structural,chemical and electrical investigations,the influences of Mn doping and substrate orientation on ferroelectric properties of Mn-doped HfO_(2)epitaxial thin films are investigated.The results demonstrate that Mn-doped HfO_(2)thin films with orthorhombic phase can be epitaxially grown along[111]out-of-plane direction on both SrTiO_(3)(001)and(110)substrates,and 10%Mn-doping significantly stabilizes the orthorhombic polar phase and enhances the ferroelectric polarization.Interestingly,compared to the films on SrTiO_(3)(001)substrate,the better crystallinity and reduction of oxygen vacancy amount in Mn-doped HfO_(2)films grown on the SrTiO_(3)(110)substrate are observed,which enhance the remanent polarization and reduce the coercive field.It provides an effective approach for the controllable regulation of defects and the enhancement of intrinsic ferroelectricity in HfO_(2)-based materials.
基金supported by the Natural Science Foundation of Guizhou Province(No.ZK 2022-044)the Platform of Science and Technology and Talent Team Plan of Guizhou Province(No.GCC[2023]007)+1 种基金the National Science Foundation of China(Nos.52101010 and 11964006)the Fund of Natural Science Special(Special Post)Research Foundation of Guizhou University(No.2021-018).
文摘The design and development of high-performance anodes pose significant challenges in the construction of next-generation rechargeable lithium-ion batteries(LIBs).Sodium molybdate dihydrate(Na_(2)MoO_(4)·2H_(2)O)has garnered increasing attention due to its cost-effectiveness,non-toxicity and earth abundance.To enhance the Li storage performance of Na_(2)MoO_(4)·2H_(2)O,a crystallographic orientation regulation strategy is proposed in this work.Initially,density functional theory calculations are carried out to demonstrate that the(020)crystal plane of Na_(2)MoO_(4)·2H_(2)O offers the lowest energy barrier for Li^(+)migration.Subsequently,the preferred crystallographic orientation of Na_(2)MoO_(4)·2H_(2)O crystal is tuned through a low-temperature recrystallization method.Furthermore,the microstructure and phase changes of Na_(2)MoO_(4)·2H_(2)O during the lithiation/de-lithiation process are studied using in situ and ex situ XRD tests,ex situ XPS and cyclic voltammetry to unravel its Li^(+)storage mechanism.Upon application as LIBs anode,the Na_(2)MoO_(4)·2H_(2)O single-crystal particles with a preferred(020)surface exhibit superior reversible capacity,high-capacity retention and high cycling stability.The enhanced Li storage performance should be attributed to the regulated crystallographic orientation and small changes in the crystal microstructure during the charge/discharge process,which facilitates Li^(+)migration and bolsters structural stability.Notably,this study introduces a novel concept and a simple synthesis method for the advancement of electrodes in rechargeable batteries.
