During the continuous casting process of high-Mn high-Al steels,various types of gases such as Ar need to escape through the top of the mold.In which,the behavior of bubbles traversing the liquid slag serves as a rest...During the continuous casting process of high-Mn high-Al steels,various types of gases such as Ar need to escape through the top of the mold.In which,the behavior of bubbles traversing the liquid slag serves as a restrictive link,closely associated with viscosity and the thickness of liquid slag.In contrast to two-dimensional surface observation,three-dimensional(3D)analysis method can offer a more intuitive,accurate,and comprehensive information.Therefore,this study employs a 3D X-ray microscope(3D-XRM)to obtained spatial distribution and 3D morphological characteristics of residual bubbles in mold flux under different basicity of liquid slag,different temperatures,and different holding times.The results indicate that as basicity of slag increases from 0.52 to 1.03,temperature increases from 1423 to 1573 K,the viscosity of slag decreases,the floating rate of bubbles increases.In addition,when holding time increases from 10 to 30 s,the bubbles floating distance increases,and the volume fraction and average equivalent sphere diameter of the bubbles solidified in the mold flux gradually decreases.In one word,increasing the basicity,temperature,and holding time leading to an increase in the removal rate of bubbles especially for the large.These findings of bubbles escape behavior provide valuable insights into optimizing low basicity mold flux for high-Mn high-Al steels.展开更多
In comparison with conventional experimental teaching methods,the implementation of the Motic digital microscope mutual system in the experimental teaching of medicinal botany has been demonstrated to be a highly effi...In comparison with conventional experimental teaching methods,the implementation of the Motic digital microscope mutual system in the experimental teaching of medicinal botany has been demonstrated to be a highly efficacious approach to enhance the teaching level of experimental courses in medicinal botany.The implementation of a digital microscope mutual system in experimental teaching not only enhances students practical skills in laboratory operations but also increases classroom efficiency.Furthermore,it supports personalized development among students while fostering innovative thinking,independent learning capabilities,and analysis and problem-solving skills.Additionally,this approach contributes to the enhancement of students scientific literacy.展开更多
To investigate the nucleation behavior during the single-phased metallic solidification process,the commercial ultrapure ferritic stainless steels with no(Initial steel)and various melt treatments(R1,MR1,Y2,MY1,and M1...To investigate the nucleation behavior during the single-phased metallic solidification process,the commercial ultrapure ferritic stainless steels with no(Initial steel)and various melt treatments(R1,MR1,Y2,MY1,and M1 steels)were used to carry out the differential scanning colorimetry(DSC)and high-temperature confocal laser scanning microscope(HT-CLSM)experiments.Based on the results of DSC experiments,the equilibrium solidification process as well as the relationship among the critical undercooling degree(△T_(c)^(DSC)),latent heat of fusion/crystallization(△H_(f)/△H_(c)),equiaxed grain ratio(ER),and average grain size(△_(ave)^(ingot))was revealed.ER is increased with the decreasing△T_(c)^(DSC)and increasing△H_(f)/△H_(c);however,△_(ave)^(ingot)is decreased with them.Referring to the results of HT-CLSM experiments,the average sizes of micro-/macrostructures(d_(ave)/D_(ave)/)are decreased with the increasing cooling rate,as well as the difference between and apparent critical undercooling degree(△T_(c)^(CLSM))was revealed.The heterogeneous nucleation of the crystal nuclei occurs only if△T_(c)^(CLSM)>△T_(c)^(DSC).Combining with the interfacial wetting-lattice mismatch heterogeneous nucleation model,the dynamic mechanism of the metallic solidification was revealed.The as-cast grains of the melt-treated samples were obviously refined,owing to the much higher actual heterogeneous nucleation rates(I_(heter.,i))obtained through melt treatments,and the heterogeneous nucleation rates(I_(heter.,ij))for all samples are increased with the cooling rates,firmly confirming that the as-cast grains of each sample could be refined by the increasing cooling rates.展开更多
Light-sheet fluorescence microscopy(LSFM)has been widely used to image the three-dimensional(3D)structures and functions of various millimeter-size bio-specimen such as zebrafish.However,the sample adsorption and scat...Light-sheet fluorescence microscopy(LSFM)has been widely used to image the three-dimensional(3D)structures and functions of various millimeter-size bio-specimen such as zebrafish.However,the sample adsorption and scattering cause shading of the light-sheet illumination,preventing the even 3D image of thick samples.Herein,we report a continuous-rotational light-sheet microscope(CR-LSM)that enables simultaneous 3D bright-field and fluorescence imaging.With a high-accuracy rotational stage,CR-LSM records the outline projections and the fluorescent images of the sample at multiple rotation angles.Then,3D morphology and fluorescent structure were reconstructed with a developed algorithm.Using CR-LSM,zebrafish’s whole-fish contour and blood vessel structures were obtained simultaneously.展开更多
The construction of advanced laboratories for precision instruments, such as electron microscopes, involves unique challenges that are influenced by the specific environmental conditions required for optimal functiona...The construction of advanced laboratories for precision instruments, such as electron microscopes, involves unique challenges that are influenced by the specific environmental conditions required for optimal functionality. These include mitigating interference from magnetic fields and vibrations, which are critical for maintaining the precision and accuracy of the instruments used. This study aims to offer enhanced project management strategies and detailed construction solutions that address the environmental and technical needs specific to electron microscopy labs, thereby facilitating effective lab operations and extending the lifecycle of high-end precision instruments. Case studies of existing laboratory constructions, onsite investigations, and comprehensive reviews of the technical and environmental requirements provide the basis for a best practice for constructing sophisticated electron microscopy labs. The approach integrates both pre-construction planning and post-construction adjustments to create optimal operational environments. The findings suggest that successful lab constructions are those that incorporate thorough onsite assessments, strategic location choices, and the use of advanced construction materials and techniques specifically designed to counteract environmental challenges like magnetic and vibration interferences. Actionable guidelines for both planning and executing the construction of electron microscope labs highlighted in this tutorial are intended as an important resource to troubleshoot or upgrade existing lab facilities and to consult in preparation of future lab construction projects.展开更多
The high-temperature dissolution behavior of primary carbides in samples taken from GCr15 continuous-casting bloom was observed in-situ by confocal laser scanning microscopy.Equations were fitted to the dissolution ki...The high-temperature dissolution behavior of primary carbides in samples taken from GCr15 continuous-casting bloom was observed in-situ by confocal laser scanning microscopy.Equations were fitted to the dissolution kinetics of primary carbides during either heating or soaking.Dissolution of carbides proceeded in three stages(fast→slow→faster)as either temperature or holding time was increased.During the heating process and during the first and third stages of the soaking process,the original size of the carbides determined the steepness of the slope,but during the middle(“slow”)stage of the soaking process,the slope remained zero.The initial size of the carbides varied greatly,but their final dissolution temperature fell within the narrow range of 1210-1235℃,and the holding time remained within 50 min.Fractal analysis was used to study the morphological characteristics of small and medium-sized carbides during the dissolution process.According to changes in the fractal dimension before and after soaking,the carbides tended to evolve towards a more regular morphology.展开更多
The hybrid CO_(2) thermal technique has achieved considerable success globally in extracting residual heavy oil from reserves following a long-term steam stimulation process.Using microscopic visualization experiments...The hybrid CO_(2) thermal technique has achieved considerable success globally in extracting residual heavy oil from reserves following a long-term steam stimulation process.Using microscopic visualization experiments and molecular dynamics(MD)simulations,this study investigates the microscopic enhanced oil recovery(EOR)mechanisms underlying residual oil removal using hybrid CO_(2) thermal systems.Based on the experimental models for the occurrence of heavy oil,this study evaluates the performance of hybrid CO_(2) thermal systems under various conditions using MD simulations.The results demonstrate that introducing CO_(2) molecules into heavy oil can effectively penetrate and decompose dense aggregates that are originally formed on hydrophobic surfaces.A stable miscible hybrid CO_(2) thermal system,with a high effective distribution ratio of CO_(2),proficiently reduces the interaction energies between heavy oil and rock surfaces,as well as within heavy oil.A visualization analysis of the interactions reveals that strong van der Waals(vdW)attractions occur between CO_(2) and heavy oil molecules,effectively promoting the decomposition and swelling of heavy oil.This unlocks the residual oil on the hydrophobic surfaces.Considering the impacts of temperature and CO_(2) concentration,an optimal gas-to-steam injection ratio(here,the CO_(2):steam ratio)ranging between 1:6 and 1:9 is recommended.This study examines the microscopic mechanisms underlying the hybrid CO_(2) thermal technique at a molecular scale,providing a significant theoretical guide for its expanded application in EOR.展开更多
SnS,a well-known van der Waals chalcogenide,is susceptible to oxidation in high-temperature or highhumidity environments,significantly impacting its functional performance and device stability.Conversely,oxidation can...SnS,a well-known van der Waals chalcogenide,is susceptible to oxidation in high-temperature or highhumidity environments,significantly impacting its functional performance and device stability.Conversely,oxidation can be used as an effective strategy for surface engineering,allowing for structure modulation or design,property tuning and application exploration.However,there is currently a gap in understanding the relationship between the oxidation behavior of SnS,the structure of its oxidized surface,and the dependence on oxidation temperature.In this study,we systematically investigated the evolution of SnS surfaces under thermal oxidation using electron microscopy.The microstructure evolution(e.g.,surface structures,phases,defects,and interface)of SnS during high-temperature oxidation has been fully characterized and studied based on cross-sectional samples.Various surface heterostructures were constructed,including SnO_(2)/SnS,SnO_(2)/SnS_(2)/SnS,and SnO_(2)/Sn_(2)S_(3)/SnS,offering significant potential for the surface functionalization of SnS-based systems.Accordingly,oxidation mechanisms at different stages were elucidated based on the detailed and clear picture of microstructures.This research not only deepens our understanding of the fundamental science of SnS oxidation but also provides valuable insights for preventing and developing surface oxidation engineering in SnS and other van der Waals chalcogenides/materials.展开更多
Manipulating and braiding Majorana zero modes(MZM)are a critical step toward realizing topological quantum computing.The primary challenge is controlling the vortex,which hosts the MZM,within a superconducting film in...Manipulating and braiding Majorana zero modes(MZM)are a critical step toward realizing topological quantum computing.The primary challenge is controlling the vortex,which hosts the MZM,within a superconducting film in a spatially precise manner.To address this,we developed a magnetic force-based vortex control technology using the STM system with a self-designed four-electrode piezo-scanner tube and investigated vortex manipulation on the NbSe_(2) superconducting film.We employed ferromagnetic tips to control the movement of vortex array induced by the tip's remanent magnetism.A magnetic core solenoid device was integrated into the STM system and a strong magnetic tip demagnetization technique was developed,providing a viable technical solution for further enabling single vortex manipulation.展开更多
Embedding optical fiber sensors into composite materials offers the advantage of real-time structural monitoring.However,there is an order-of-magnitude difference in diameter between optical fibers and reinforcing fib...Embedding optical fiber sensors into composite materials offers the advantage of real-time structural monitoring.However,there is an order-of-magnitude difference in diameter between optical fibers and reinforcing fibers,and the detailed mechanism of how embedded optical fibers affect the micromechanical behavior and damage failure processes within composite materials remains unclear.This paper presents a micromechanical simulation analysis of composite materials embedded with optical fibers.By constructing representative volume elements(RVEs)with randomly distributed reinforcing fibers,the optical fiber,the matrix,and the interface phase,the micromechanical behavior and damage evolution under transverse tensile and compressive loads are explored.The study finds that the presence of embedded optical fibers significantly influences the initiation and propagation of microscopic damage within the composites.Under transverse tension,the fiber-matrix interface cracks first,followed by plastic cracking in the matrix surrounding the fibers,forming micro-cracks.Eventually,these cracks connect with the debonded areas at the fiber-matrix interface to form a dominant crack that spans the entire model.Under transverse compression,plastic cracking first occurs in the resin surrounding the optical fibers,connecting with the interface debonding areas between the optical fibers and the matrix to form two parallel shear bands.Additionally,it is observed that the strength of the interface between the optical fiber and the matrix critically affects the simulation results.The simulated damage morphologies align closely with those observed using scanning electron microscopy(SEM).These findings offer theoretical insights that can inform the design and fabrication of smart composite materials with embedded optical fiber sensors for advanced structural health monitoring.展开更多
Recent advances in artificial intelligence(AI)have led to the development of sophisticated algorithms that significantly improve image analysis capabilities.This combination of AI and microscopic imaging is transformi...Recent advances in artificial intelligence(AI)have led to the development of sophisticated algorithms that significantly improve image analysis capabilities.This combination of AI and microscopic imaging is transforming the way we interpret and analyze imaging data,simplifying complex tasks and enabling innovative experimental methods previously thought impossible.In smart manufacturing,these improvements are especially impactful,increasing precision and efficiency in production processes.This review examines the convergence of AI with particle image analysis,an area we refer to as“particle vision analysis(PVA).”We offer a detailed overview of how this technology integrates into and impacts various fields within the physical sciences and materials sectors,where it plays a crucial role in both innovation and operational improvements.We explore four key areas of advancement-namely,particle classification,detection,segmentation,and object tracking-along with a look into the emerging field of augmented microscopy.This paper also underscores the vital role of the existing datasets and implementations that support these applications,which provide essential insights and resources that drive continuous research and development in this fast-evolving field.Our thorough analysis aims to outline the transformative potential of AI-driven PVA in improving precision in future manufacturing at the microscopic scale and thereby preparing the ground for significant technological progress and broad industrial applications in nanomanufacturing,biomanufacturing,and pharmaceutical manufacturing.This exploration not only highlights the advantages of integrating AI into conventional manufacturing processes but also anticipates the rise of next-generation smart manufacturing,which is set to revolutionize industry standards and operational practices.展开更多
Accurate prediction of coal reservoir permeability is crucial for engineering applications,including coal mining,coalbed methane(CBM)extraction,and carbon storage in deep unmineable coal seams.Owing to the inherent he...Accurate prediction of coal reservoir permeability is crucial for engineering applications,including coal mining,coalbed methane(CBM)extraction,and carbon storage in deep unmineable coal seams.Owing to the inherent heterogeneity and complex internal structure of coal,a well-established method for predicting permeability based on microscopic fracture structures remains elusive.This paper presents a novel integrated approach that leverages the intrinsic relationship between microscopic fracture structure and permeability to construct a predictive model for coal permeability.The proposed framework encompasses data generation through the integration of three-dimensional(3D)digital core analysis and numerical simulations,followed by data-driven modeling via machine learning(ML)techniques.Key data-driven strategies,including feature selection and hyperparameter tuning,are employed to improve model performance.We propose and evaluate twelve data-driven models,including multilayer perceptron(MLP),random forest(RF),and hybrid methods.The results demonstrate that the ML model based on the RF algorithm achieves the highest accuracy and best generalization capability in predicting permeability.This method enables rapid estimation of coal permeability by inputting two-dimensional(2D)computed tomography images or parameters of the microscopic fracture structure,thereby providing an accurate and efficient means of permeability prediction.展开更多
Intracranial aneurysms,characterized by focal arterial wall dilation,pose significant neurosurgical challenges due to their potential for rupture and hemorrhage,leading to severe clinical outcomes,including fatality.P...Intracranial aneurysms,characterized by focal arterial wall dilation,pose significant neurosurgical challenges due to their potential for rupture and hemorrhage,leading to severe clinical outcomes,including fatality.Patients often experience profound psychological and social impacts,such as depression,anxiety,and cognitive impairment,affecting their quality of life.Rapid progression and high mortality necessitate timely intervention.Advances in neurosurgical techniques,including microscopic surgery and neuroendoscopy,offer distinct advantages.Microscopic surgery provides precision and direct visualization,while neuroendoscopy ensures minimally invasive access and reduced tissue trauma.Integrating these methods optimizes treatment efficacy and clinical outcomes.AIM To evaluate the impact of combined microscopic and neuroendoscopic techniques on psychological,cognitive outcomes,and quality of life in patients with ruptured intracranial aneurysms.METHODS The study focused on 189 patients with intracranial aneurysm rupture and hemorrhage from January 2020 to May 2024 as the objects of observation and analysis.They were randomly divided into a control group(treated with simple microscope surgery,n=94)and an observation group(treated with microscope combined with neuroendoscopy,n=95).The treatment effects of the two groups were observed,mainly including depression and anxiety scale scores,cognitive function assessment results and quality of life assessment data.RESULTS Before treatment,the depression and anxiety scale scores,cognitive function assessment results and quality of life assessment data of the two groups of patients at different time points were compared,and there was no statistically significant difference(P>0.05).After microscope combined with neuroendoscopy treatment,the study revealed that the observation group surpassed the control group in alleviating depression and anxiety,accelerating cognitive function recovery,and enhancing quality of life,with these differences being statistically significant(P<0.05).CONCLUSION Surgical treatment combined with microscopy and neuroendoscopy has a significant positive effect on the mental health,cognitive function and overall quality of life of patients with intracranial aneurysm rupture and bleeding,can shorten the operation time and treatment time,and provides a new strategic reference for clinical treatment.展开更多
Triple-negative breast cancer (TNBC) is an aggressive and often fatal disease, especially since the brain metastasis of TNBC has been a particularly severe manifestation. However, brain metastasis in TNBC at early sta...Triple-negative breast cancer (TNBC) is an aggressive and often fatal disease, especially since the brain metastasis of TNBC has been a particularly severe manifestation. However, brain metastasis in TNBC at early stages often lacks noticeable symptoms, making it challenging to detect. Near-infrared II (NIR-II) fluorescence microscopic imaging obtains long wavelength, which enables reduced scattering, high spatial resolution and minimal autofluorescence, it is also a favorable imaging method for tumor diagnosis. PbS@CdS quantum dots (QDs) are one of the popular NIR-II fluorescence nanoprobes for well brightness. In this study, NIR-II emissive PbS@CdS QDs were utilized and further encapsulated with thiol-terminated poly(ethylene oxide) (SH-PEG, MW = 5000) to form PbS@CdS@PEG QDs nanoparticles (NPs). The obtained PbS@CdS@PEG QDs NPs were then characterized and further studied in detail. The PbS@CdS@PEG QDs NPs had large absorption spectra, exhibited strong NIR-II fluorescence emission at approximately 1300nm, and possessed good NIR-II fluorescence properties. Then, the mice model of early-stage brain metastases of TNBC was established, and the PbS@CdS@PEG QDs NPs were injected into the tumor-bearing mice for NIR-II fluorescence microscopic bioimaging. The brain vessels and tumors of the living mice were detected with high spatial resolution under the NIR-II fluorescence microscopic imaging system with irradiation of 808nm laser. The tumor tissues were further restricted and prepared as thin slices. The NIR-II fluorescence signals were collected from the tumor slices with high spatial resolution and signal-to-background ratio (SBR). Thus, the PbS@CdS@PEG QDs NPs-assisted NIR-II fluorescence microscopic system can effectively achieve targeting brain metastases of TNBC imaging, offering a novel and promising approach for TNBC-specific diagnosis.展开更多
The deformation characteristics of silty soils under vibrational loads can easily change due to the wetting process,leading to the failure of roadbed structures.Commonly used methods for improving silty soils in engin...The deformation characteristics of silty soils under vibrational loads can easily change due to the wetting process,leading to the failure of roadbed structures.Commonly used methods for improving silty soils in engineering often yield unsatisfactory economic and ecological outcomes.As an environment-friendly soil improvement material,Xanthan gum has broad application prospects and is therefore considered a solidifying agent for enhancing silty soil properties in the Yellow River Basin.In this study,a series of tests is conducted using a scanning electron microscope and a dynamic triaxial testing apparatus to investigate the microstructure and dynamic deformation characteristics of unsaturated silty soil with varying xanthan gum contents during the wetting process.The results show that xanthan gum effectively fills voids between soil particles and adheres to their surfaces,forming fibrous and network structures.This modification enhances the inherent properties of the silty soil and significantly improves its stability under dynamic loading.Specifically,with increasing xanthan gum content,the dynamic shear modulus increases while the damping ratio decreases.During the wetting process,as suction decreases,the dynamic shear modulus decreases while the damping ratio increases.Xanthan gum reduces the sensitivity of the dynamic deformation characteristics of the treated silty soil to changes in suction levels.Finally,based on the modified Hardin-Drnevich hyperbolic model,a predictive model for the dynamic shear modulus and damping ratio of treated silty soil is proposed,considering the xanthan gum content.These research findings provide a theoretical basis for the construction and maintenance of water conservancy,slope stabilization,and roadbed projects in the Yellow River Basin.展开更多
A collaborative optimization method for the sintering schedule of ternary cathode materials was proposed under microscopic coupling constraints.An oxygen vacancy concentration prediction model based on microscopic the...A collaborative optimization method for the sintering schedule of ternary cathode materials was proposed under microscopic coupling constraints.An oxygen vacancy concentration prediction model based on microscopic thermodynamics and a growth kinetics model based on neural networks were established.Then,optimization formulations were constructed in three stages to obtain an optimal sintering schedule that minimized energy consumption for different requirements.Simulations demonstrate that the models accurately predict the oxygen vacancy concentrations and grain size,with root mean square errors of approximately 5%and 3%,respectively.Furthermore,the optimized sintering schedule not only meets the required quality standards but also reduces sintering time by 12.31%and keeping temperature by 11.96%.This research provides new insights and methods for the preparation of ternary cathode materials.展开更多
During the thawing process of a railway subgrade,bidirectional thawing complicates water-heat transfer,leading to serious thaw settlement issues under train loads.Focusing on the severely frozen section of the Shuozho...During the thawing process of a railway subgrade,bidirectional thawing complicates water-heat transfer,leading to serious thaw settlement issues under train loads.Focusing on the severely frozen section of the Shuozhou-Huanghua port heavy-haul railway,this study conducted indoor soil-column laterally-limited compression tests on thawing fine-grained soil specimens to analyze the cumulative deformation during thawing.The deformation evolution was examined from both macroscopic and microscopic perspectives.The test results revealed a sig-nificant increase in the water content at the frozen interlayer during thawing,with minimal thaw settlement under no-load conditions.However,under dynamic loads,the thawing soil exhibited rapid settlement during the initial stages of the process.Increasing the dynamic load amplitude did not result in significant additional thaw settlement compression.Particle image velocimetry revealed substantial thaw settlement and compression at the top of thawing soil.Microscopically,the porosity at the top of the specimens significantly decreased,whereas the porosity in the frozen interlayer remained largely unchanged.Under dynamic loading,the specimens exhibited a concentrated distribution of large pores with scattered smaller pores.The phase change from ice to water,combined with dynamic loading,induced particle movement and expanded the inter-particle pore space,leading to macroscopic thaw settlement and soil compression.The findings can provide a theoretical foundation for maintaining and ensuring the safety of railway subgrades in cold regions.展开更多
Dissolution kinetics of CaO·2Al_(2)O_(3)(CA_(2))particles in a synthetic CaO-Al_(2)O_(3)-SiO_(2)steelmaking slag system have been investigated using the high-temperature confocal laser scanning microscope.Effects...Dissolution kinetics of CaO·2Al_(2)O_(3)(CA_(2))particles in a synthetic CaO-Al_(2)O_(3)-SiO_(2)steelmaking slag system have been investigated using the high-temperature confocal laser scanning microscope.Effects of temperature(i.e.,1500,1550,and 1600℃)and slag composition on the dissolution time of CA_(2)particles are investigated,along with the time dependency of the projection area of the particle during the dissolution process.It is found that the dissolution rate was enhanced by either an increase in temperature or a decrease in slag viscosity.Moreover,a higher ratio of CaO/Al_(2)O_(3)(C/A)leads to an increased dissolution rate of CA_(2)particle at 1600℃.Thermodynamic calculations suggested the dissolution product,i.e.,melilite,formed on the surface of the CA_(2)particle during dissolution in slag with a C/A ratio of 3.8 at 1550℃.Scanning electron microscopy equipped with energy dispersive X-ray spectrometry analysis of as-quenched samples confirmed the dissolution path of CA_(2)particles in slags with C/A ratios of 1.8 and 3.8 as well as the melilite formed on the surface of CA_(2)particle.The formation of this layer during the dissolution process was identified as a hindrance,impeding the dissolution of CA_(2)particle.A valuable reference for designing or/and choosing the composition of top slag for clean steel production is provided,especially using calcium treatment during the secondary refining process.展开更多
[Objectives] To identify Pyrostegia venusta (Ker-Gawler.) Miers by microscope and ultraviolet spectrum. [Methods] The paraffin section, slide section and freehand section were used to make the cross section of the ste...[Objectives] To identify Pyrostegia venusta (Ker-Gawler.) Miers by microscope and ultraviolet spectrum. [Methods] The paraffin section, slide section and freehand section were used to make the cross section of the stem and leaf, and the surface of the leaf and the powder of the root, stem and leaf were made by the conventional method, which were observed under the optical microscope. Ultraviolet-visible spectrum identification was carried out according to a conventional method. [Results] The microscopic identification and ultraviolet-visible absorption characteristics of P. venusta (Ker-Gawler) Miers were described in detail. [Conclusions] This study is expected to provide a reference for the identification of P. venusta(KerGawler)Miers and the establishment of the related quality standard.展开更多
The excellent bonding performance between bolt and anchor materials is crucial for controlling the deformation of deep-buried surrounding rock and strengthening the rock and soil mass in the slope.This paper conducted...The excellent bonding performance between bolt and anchor materials is crucial for controlling the deformation of deep-buried surrounding rock and strengthening the rock and soil mass in the slope.This paper conducted an anchoring test and ABAQUS numerical simulation of an anchoring system comprising a micro-NPR(microscopic negative Poisson’s ratio)bolt and cement mortar as the anchoring material.The failure mode of this system and the distribution of average bonding strength,axial force,and shear stress along the anchoring depth were studied.We also evaluated the bonding properties at the micro-NPR(microscopic negative Poisson’s ratio)bolt-cement mortar interface.The findings indicate that the cement mortar is partially spalled from the micro-NPR bolt surface.The average bonding strength at the micro-NPR bolt-cement mortar interface is positively correlated with anchoring length and cement mortar strength.In contrast,it exhibits a negative correlation with bolt diameter.The axial force is generated at the starting point of the anchorage and decreases non-uniformly across the anchoring region.The axial force transfers or diffuses toward the deeper sections of the anchoring segment with increasing loads.The shear stress at the micro-NPR bolt-cement mortar interface exhibits a single-peak pattern,i.e.,it climbs to a peak value and decreases along the anchoring depth.The peak position varies with changes in bolt diameter and anchoring length.By comparison,it is independent of cement mortar strength.The simulated bonding properties of the micro-NPR bolt-cement mortar interface are consistent with experimental results.The findings can provide a reference for engineering applications and anchoring design of micro-NPR.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.52274315 and 52374320)the Fundamental Research Funds for the Central Universities(Nos.FRF-TP-22-011A1 and FRF-DF22-16)。
文摘During the continuous casting process of high-Mn high-Al steels,various types of gases such as Ar need to escape through the top of the mold.In which,the behavior of bubbles traversing the liquid slag serves as a restrictive link,closely associated with viscosity and the thickness of liquid slag.In contrast to two-dimensional surface observation,three-dimensional(3D)analysis method can offer a more intuitive,accurate,and comprehensive information.Therefore,this study employs a 3D X-ray microscope(3D-XRM)to obtained spatial distribution and 3D morphological characteristics of residual bubbles in mold flux under different basicity of liquid slag,different temperatures,and different holding times.The results indicate that as basicity of slag increases from 0.52 to 1.03,temperature increases from 1423 to 1573 K,the viscosity of slag decreases,the floating rate of bubbles increases.In addition,when holding time increases from 10 to 30 s,the bubbles floating distance increases,and the volume fraction and average equivalent sphere diameter of the bubbles solidified in the mold flux gradually decreases.In one word,increasing the basicity,temperature,and holding time leading to an increase in the removal rate of bubbles especially for the large.These findings of bubbles escape behavior provide valuable insights into optimizing low basicity mold flux for high-Mn high-Al steels.
基金Supported by Major Project of School-level Teaching Reform and Research of Guangxi University of Chinese Medicine(2022A006)。
文摘In comparison with conventional experimental teaching methods,the implementation of the Motic digital microscope mutual system in the experimental teaching of medicinal botany has been demonstrated to be a highly efficacious approach to enhance the teaching level of experimental courses in medicinal botany.The implementation of a digital microscope mutual system in experimental teaching not only enhances students practical skills in laboratory operations but also increases classroom efficiency.Furthermore,it supports personalized development among students while fostering innovative thinking,independent learning capabilities,and analysis and problem-solving skills.Additionally,this approach contributes to the enhancement of students scientific literacy.
基金supported by the National Natural Science Foundation of China(Grant Nos.52274339,52174321,52074186,and 52104337)Natural Science Foundation of Jiangsu Province(Grant No.BK20231317)China Baowu Low-Carbon Metallurgy Innovation Fund(Grant No.BWLCF202108).
文摘To investigate the nucleation behavior during the single-phased metallic solidification process,the commercial ultrapure ferritic stainless steels with no(Initial steel)and various melt treatments(R1,MR1,Y2,MY1,and M1 steels)were used to carry out the differential scanning colorimetry(DSC)and high-temperature confocal laser scanning microscope(HT-CLSM)experiments.Based on the results of DSC experiments,the equilibrium solidification process as well as the relationship among the critical undercooling degree(△T_(c)^(DSC)),latent heat of fusion/crystallization(△H_(f)/△H_(c)),equiaxed grain ratio(ER),and average grain size(△_(ave)^(ingot))was revealed.ER is increased with the decreasing△T_(c)^(DSC)and increasing△H_(f)/△H_(c);however,△_(ave)^(ingot)is decreased with them.Referring to the results of HT-CLSM experiments,the average sizes of micro-/macrostructures(d_(ave)/D_(ave)/)are decreased with the increasing cooling rate,as well as the difference between and apparent critical undercooling degree(△T_(c)^(CLSM))was revealed.The heterogeneous nucleation of the crystal nuclei occurs only if△T_(c)^(CLSM)>△T_(c)^(DSC).Combining with the interfacial wetting-lattice mismatch heterogeneous nucleation model,the dynamic mechanism of the metallic solidification was revealed.The as-cast grains of the melt-treated samples were obviously refined,owing to the much higher actual heterogeneous nucleation rates(I_(heter.,i))obtained through melt treatments,and the heterogeneous nucleation rates(I_(heter.,ij))for all samples are increased with the cooling rates,firmly confirming that the as-cast grains of each sample could be refined by the increasing cooling rates.
基金the National Natural Science Foundation of China(62205368)the Key Research and Development Program of Jiangsu Province(BE2020664).
文摘Light-sheet fluorescence microscopy(LSFM)has been widely used to image the three-dimensional(3D)structures and functions of various millimeter-size bio-specimen such as zebrafish.However,the sample adsorption and scattering cause shading of the light-sheet illumination,preventing the even 3D image of thick samples.Herein,we report a continuous-rotational light-sheet microscope(CR-LSM)that enables simultaneous 3D bright-field and fluorescence imaging.With a high-accuracy rotational stage,CR-LSM records the outline projections and the fluorescent images of the sample at multiple rotation angles.Then,3D morphology and fluorescent structure were reconstructed with a developed algorithm.Using CR-LSM,zebrafish’s whole-fish contour and blood vessel structures were obtained simultaneously.
文摘The construction of advanced laboratories for precision instruments, such as electron microscopes, involves unique challenges that are influenced by the specific environmental conditions required for optimal functionality. These include mitigating interference from magnetic fields and vibrations, which are critical for maintaining the precision and accuracy of the instruments used. This study aims to offer enhanced project management strategies and detailed construction solutions that address the environmental and technical needs specific to electron microscopy labs, thereby facilitating effective lab operations and extending the lifecycle of high-end precision instruments. Case studies of existing laboratory constructions, onsite investigations, and comprehensive reviews of the technical and environmental requirements provide the basis for a best practice for constructing sophisticated electron microscopy labs. The approach integrates both pre-construction planning and post-construction adjustments to create optimal operational environments. The findings suggest that successful lab constructions are those that incorporate thorough onsite assessments, strategic location choices, and the use of advanced construction materials and techniques specifically designed to counteract environmental challenges like magnetic and vibration interferences. Actionable guidelines for both planning and executing the construction of electron microscope labs highlighted in this tutorial are intended as an important resource to troubleshoot or upgrade existing lab facilities and to consult in preparation of future lab construction projects.
基金supported by Independent Research Project of State Key Laboratory of Advanced Special Steel,Shanghai Key Laboratory of Advanced Ferrometallurgy,Shanghai University(SKLASS-2023-Z13)the Science and Technology Commission of Shanghai Municipality(No.19DZ2270200)+1 种基金A portion of the work was performed at US National High Magnetic Field Laboratory,which is supported by the National Science Foundation(Cooperative Agreement No.DMR-1157490 and DMR-1644779)the State of Florida.Thanks also to Mary Tyler for editing.
文摘The high-temperature dissolution behavior of primary carbides in samples taken from GCr15 continuous-casting bloom was observed in-situ by confocal laser scanning microscopy.Equations were fitted to the dissolution kinetics of primary carbides during either heating or soaking.Dissolution of carbides proceeded in three stages(fast→slow→faster)as either temperature or holding time was increased.During the heating process and during the first and third stages of the soaking process,the original size of the carbides determined the steepness of the slope,but during the middle(“slow”)stage of the soaking process,the slope remained zero.The initial size of the carbides varied greatly,but their final dissolution temperature fell within the narrow range of 1210-1235℃,and the holding time remained within 50 min.Fractal analysis was used to study the morphological characteristics of small and medium-sized carbides during the dissolution process.According to changes in the fractal dimension before and after soaking,the carbides tended to evolve towards a more regular morphology.
基金financially supported by the National Natural Science Foundation of China(No.U20B6003)the China Scholarship Council(No.202306440015)a project of the China Petroleum&Chemical Corporation(No.P22174)。
文摘The hybrid CO_(2) thermal technique has achieved considerable success globally in extracting residual heavy oil from reserves following a long-term steam stimulation process.Using microscopic visualization experiments and molecular dynamics(MD)simulations,this study investigates the microscopic enhanced oil recovery(EOR)mechanisms underlying residual oil removal using hybrid CO_(2) thermal systems.Based on the experimental models for the occurrence of heavy oil,this study evaluates the performance of hybrid CO_(2) thermal systems under various conditions using MD simulations.The results demonstrate that introducing CO_(2) molecules into heavy oil can effectively penetrate and decompose dense aggregates that are originally formed on hydrophobic surfaces.A stable miscible hybrid CO_(2) thermal system,with a high effective distribution ratio of CO_(2),proficiently reduces the interaction energies between heavy oil and rock surfaces,as well as within heavy oil.A visualization analysis of the interactions reveals that strong van der Waals(vdW)attractions occur between CO_(2) and heavy oil molecules,effectively promoting the decomposition and swelling of heavy oil.This unlocks the residual oil on the hydrophobic surfaces.Considering the impacts of temperature and CO_(2) concentration,an optimal gas-to-steam injection ratio(here,the CO_(2):steam ratio)ranging between 1:6 and 1:9 is recommended.This study examines the microscopic mechanisms underlying the hybrid CO_(2) thermal technique at a molecular scale,providing a significant theoretical guide for its expanded application in EOR.
基金financially supported by the National Natural Science Foundation of China(Nos.11904039,52125103,52071041,U21A2054 and 12104071)。
文摘SnS,a well-known van der Waals chalcogenide,is susceptible to oxidation in high-temperature or highhumidity environments,significantly impacting its functional performance and device stability.Conversely,oxidation can be used as an effective strategy for surface engineering,allowing for structure modulation or design,property tuning and application exploration.However,there is currently a gap in understanding the relationship between the oxidation behavior of SnS,the structure of its oxidized surface,and the dependence on oxidation temperature.In this study,we systematically investigated the evolution of SnS surfaces under thermal oxidation using electron microscopy.The microstructure evolution(e.g.,surface structures,phases,defects,and interface)of SnS during high-temperature oxidation has been fully characterized and studied based on cross-sectional samples.Various surface heterostructures were constructed,including SnO_(2)/SnS,SnO_(2)/SnS_(2)/SnS,and SnO_(2)/Sn_(2)S_(3)/SnS,offering significant potential for the surface functionalization of SnS-based systems.Accordingly,oxidation mechanisms at different stages were elucidated based on the detailed and clear picture of microstructures.This research not only deepens our understanding of the fundamental science of SnS oxidation but also provides valuable insights for preventing and developing surface oxidation engineering in SnS and other van der Waals chalcogenides/materials.
基金Project supported by the National Key Research&Development Program of China(Grant Nos.2019YFA0308600 and 2020YFA0309000)the National Natural Science Foundation of China(Grant Nos.92365302,92065201,22325203,92265105,12074247,12174252,52102336)+2 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB28000000)the Science and Technology Commission of Shanghai Municipality(Grant Nos.2019SHZDZX01,19JC1412701,20QA1405100,24LZ1401000,LZPY2024-04)financial support from the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0302500)。
文摘Manipulating and braiding Majorana zero modes(MZM)are a critical step toward realizing topological quantum computing.The primary challenge is controlling the vortex,which hosts the MZM,within a superconducting film in a spatially precise manner.To address this,we developed a magnetic force-based vortex control technology using the STM system with a self-designed four-electrode piezo-scanner tube and investigated vortex manipulation on the NbSe_(2) superconducting film.We employed ferromagnetic tips to control the movement of vortex array induced by the tip's remanent magnetism.A magnetic core solenoid device was integrated into the STM system and a strong magnetic tip demagnetization technique was developed,providing a viable technical solution for further enabling single vortex manipulation.
基金funded by the National Key Research and Development Program of China(Grant No.2022YFB3402500)the National Natural Science Foundation of China(Grant No.12372129).
文摘Embedding optical fiber sensors into composite materials offers the advantage of real-time structural monitoring.However,there is an order-of-magnitude difference in diameter between optical fibers and reinforcing fibers,and the detailed mechanism of how embedded optical fibers affect the micromechanical behavior and damage failure processes within composite materials remains unclear.This paper presents a micromechanical simulation analysis of composite materials embedded with optical fibers.By constructing representative volume elements(RVEs)with randomly distributed reinforcing fibers,the optical fiber,the matrix,and the interface phase,the micromechanical behavior and damage evolution under transverse tensile and compressive loads are explored.The study finds that the presence of embedded optical fibers significantly influences the initiation and propagation of microscopic damage within the composites.Under transverse tension,the fiber-matrix interface cracks first,followed by plastic cracking in the matrix surrounding the fibers,forming micro-cracks.Eventually,these cracks connect with the debonded areas at the fiber-matrix interface to form a dominant crack that spans the entire model.Under transverse compression,plastic cracking first occurs in the resin surrounding the optical fibers,connecting with the interface debonding areas between the optical fibers and the matrix to form two parallel shear bands.Additionally,it is observed that the strength of the interface between the optical fiber and the matrix critically affects the simulation results.The simulated damage morphologies align closely with those observed using scanning electron microscopy(SEM).These findings offer theoretical insights that can inform the design and fabrication of smart composite materials with embedded optical fiber sensors for advanced structural health monitoring.
基金funding support from the US National Science Foundation(2229092)supported by the Eric and Wendy Schmidt AI in Science Postdoctoral Fellowship,a program of Schmidt Sciences,LLC.
文摘Recent advances in artificial intelligence(AI)have led to the development of sophisticated algorithms that significantly improve image analysis capabilities.This combination of AI and microscopic imaging is transforming the way we interpret and analyze imaging data,simplifying complex tasks and enabling innovative experimental methods previously thought impossible.In smart manufacturing,these improvements are especially impactful,increasing precision and efficiency in production processes.This review examines the convergence of AI with particle image analysis,an area we refer to as“particle vision analysis(PVA).”We offer a detailed overview of how this technology integrates into and impacts various fields within the physical sciences and materials sectors,where it plays a crucial role in both innovation and operational improvements.We explore four key areas of advancement-namely,particle classification,detection,segmentation,and object tracking-along with a look into the emerging field of augmented microscopy.This paper also underscores the vital role of the existing datasets and implementations that support these applications,which provide essential insights and resources that drive continuous research and development in this fast-evolving field.Our thorough analysis aims to outline the transformative potential of AI-driven PVA in improving precision in future manufacturing at the microscopic scale and thereby preparing the ground for significant technological progress and broad industrial applications in nanomanufacturing,biomanufacturing,and pharmaceutical manufacturing.This exploration not only highlights the advantages of integrating AI into conventional manufacturing processes but also anticipates the rise of next-generation smart manufacturing,which is set to revolutionize industry standards and operational practices.
基金supported by the Zhejiang Provincial Natural Science Foundation of China(Grant No.LY23E040001)Fundamental Research Funding Project of Zhejiang Province,China(Project Category A,Grant No.2022YW06)National Key R&D Program of China(Grant No.2023YFF0614902).
文摘Accurate prediction of coal reservoir permeability is crucial for engineering applications,including coal mining,coalbed methane(CBM)extraction,and carbon storage in deep unmineable coal seams.Owing to the inherent heterogeneity and complex internal structure of coal,a well-established method for predicting permeability based on microscopic fracture structures remains elusive.This paper presents a novel integrated approach that leverages the intrinsic relationship between microscopic fracture structure and permeability to construct a predictive model for coal permeability.The proposed framework encompasses data generation through the integration of three-dimensional(3D)digital core analysis and numerical simulations,followed by data-driven modeling via machine learning(ML)techniques.Key data-driven strategies,including feature selection and hyperparameter tuning,are employed to improve model performance.We propose and evaluate twelve data-driven models,including multilayer perceptron(MLP),random forest(RF),and hybrid methods.The results demonstrate that the ML model based on the RF algorithm achieves the highest accuracy and best generalization capability in predicting permeability.This method enables rapid estimation of coal permeability by inputting two-dimensional(2D)computed tomography images or parameters of the microscopic fracture structure,thereby providing an accurate and efficient means of permeability prediction.
文摘Intracranial aneurysms,characterized by focal arterial wall dilation,pose significant neurosurgical challenges due to their potential for rupture and hemorrhage,leading to severe clinical outcomes,including fatality.Patients often experience profound psychological and social impacts,such as depression,anxiety,and cognitive impairment,affecting their quality of life.Rapid progression and high mortality necessitate timely intervention.Advances in neurosurgical techniques,including microscopic surgery and neuroendoscopy,offer distinct advantages.Microscopic surgery provides precision and direct visualization,while neuroendoscopy ensures minimally invasive access and reduced tissue trauma.Integrating these methods optimizes treatment efficacy and clinical outcomes.AIM To evaluate the impact of combined microscopic and neuroendoscopic techniques on psychological,cognitive outcomes,and quality of life in patients with ruptured intracranial aneurysms.METHODS The study focused on 189 patients with intracranial aneurysm rupture and hemorrhage from January 2020 to May 2024 as the objects of observation and analysis.They were randomly divided into a control group(treated with simple microscope surgery,n=94)and an observation group(treated with microscope combined with neuroendoscopy,n=95).The treatment effects of the two groups were observed,mainly including depression and anxiety scale scores,cognitive function assessment results and quality of life assessment data.RESULTS Before treatment,the depression and anxiety scale scores,cognitive function assessment results and quality of life assessment data of the two groups of patients at different time points were compared,and there was no statistically significant difference(P>0.05).After microscope combined with neuroendoscopy treatment,the study revealed that the observation group surpassed the control group in alleviating depression and anxiety,accelerating cognitive function recovery,and enhancing quality of life,with these differences being statistically significant(P<0.05).CONCLUSION Surgical treatment combined with microscopy and neuroendoscopy has a significant positive effect on the mental health,cognitive function and overall quality of life of patients with intracranial aneurysm rupture and bleeding,can shorten the operation time and treatment time,and provides a new strategic reference for clinical treatment.
基金supported by the National Natural Science Foundation of China(NSFC)under Grant Nos.62035011,82202220 and 82060326State Key Laboratory of Pathogenesis,Prevention and treat ment of High Incident Diseases in central Asia(Nos.SKL-HIDCA-2022-3 and SKL-HIDCA-2022-GJ1)+3 种基金the Xinjiang Uygur Autonomous Region Regional Collaborative Innovation Special Science and Technology Assistance Program(No.2022E02130)Xinjiang Uygur Autonomous Region Natural Sci ence Foundation Key Project(No.2022D01D40)Outstanding Youth Project(2023D01E06)Y.Gao and C.Zhang authors contributed equally to this work.
文摘Triple-negative breast cancer (TNBC) is an aggressive and often fatal disease, especially since the brain metastasis of TNBC has been a particularly severe manifestation. However, brain metastasis in TNBC at early stages often lacks noticeable symptoms, making it challenging to detect. Near-infrared II (NIR-II) fluorescence microscopic imaging obtains long wavelength, which enables reduced scattering, high spatial resolution and minimal autofluorescence, it is also a favorable imaging method for tumor diagnosis. PbS@CdS quantum dots (QDs) are one of the popular NIR-II fluorescence nanoprobes for well brightness. In this study, NIR-II emissive PbS@CdS QDs were utilized and further encapsulated with thiol-terminated poly(ethylene oxide) (SH-PEG, MW = 5000) to form PbS@CdS@PEG QDs nanoparticles (NPs). The obtained PbS@CdS@PEG QDs NPs were then characterized and further studied in detail. The PbS@CdS@PEG QDs NPs had large absorption spectra, exhibited strong NIR-II fluorescence emission at approximately 1300nm, and possessed good NIR-II fluorescence properties. Then, the mice model of early-stage brain metastases of TNBC was established, and the PbS@CdS@PEG QDs NPs were injected into the tumor-bearing mice for NIR-II fluorescence microscopic bioimaging. The brain vessels and tumors of the living mice were detected with high spatial resolution under the NIR-II fluorescence microscopic imaging system with irradiation of 808nm laser. The tumor tissues were further restricted and prepared as thin slices. The NIR-II fluorescence signals were collected from the tumor slices with high spatial resolution and signal-to-background ratio (SBR). Thus, the PbS@CdS@PEG QDs NPs-assisted NIR-II fluorescence microscopic system can effectively achieve targeting brain metastases of TNBC imaging, offering a novel and promising approach for TNBC-specific diagnosis.
基金supported by the Postgraduate Education Reform and Quality Improvement Project of Henan Province,China(Grant No.YJS2023AL004)the Graduate Innovation Project of North China University of Water Resources and Electric Power(Grant No.NCWUYC-202315069)the China National Scholarship Fund organized by the China Scholarship Council(Grant No.202208410337).
文摘The deformation characteristics of silty soils under vibrational loads can easily change due to the wetting process,leading to the failure of roadbed structures.Commonly used methods for improving silty soils in engineering often yield unsatisfactory economic and ecological outcomes.As an environment-friendly soil improvement material,Xanthan gum has broad application prospects and is therefore considered a solidifying agent for enhancing silty soil properties in the Yellow River Basin.In this study,a series of tests is conducted using a scanning electron microscope and a dynamic triaxial testing apparatus to investigate the microstructure and dynamic deformation characteristics of unsaturated silty soil with varying xanthan gum contents during the wetting process.The results show that xanthan gum effectively fills voids between soil particles and adheres to their surfaces,forming fibrous and network structures.This modification enhances the inherent properties of the silty soil and significantly improves its stability under dynamic loading.Specifically,with increasing xanthan gum content,the dynamic shear modulus increases while the damping ratio decreases.During the wetting process,as suction decreases,the dynamic shear modulus decreases while the damping ratio increases.Xanthan gum reduces the sensitivity of the dynamic deformation characteristics of the treated silty soil to changes in suction levels.Finally,based on the modified Hardin-Drnevich hyperbolic model,a predictive model for the dynamic shear modulus and damping ratio of treated silty soil is proposed,considering the xanthan gum content.These research findings provide a theoretical basis for the construction and maintenance of water conservancy,slope stabilization,and roadbed projects in the Yellow River Basin.
基金supported by the National Natural Science Foundation of China(No.62033014)the Application Projects of Integrated Standardization and New Paradigm for Intelligent Manufacturing from the Ministry of Industry and Information Technology of China in 2016,and the Fundamental Research Funds for the Central Universities of Central South University,China(No.2021zzts0700).
文摘A collaborative optimization method for the sintering schedule of ternary cathode materials was proposed under microscopic coupling constraints.An oxygen vacancy concentration prediction model based on microscopic thermodynamics and a growth kinetics model based on neural networks were established.Then,optimization formulations were constructed in three stages to obtain an optimal sintering schedule that minimized energy consumption for different requirements.Simulations demonstrate that the models accurately predict the oxygen vacancy concentrations and grain size,with root mean square errors of approximately 5%and 3%,respectively.Furthermore,the optimized sintering schedule not only meets the required quality standards but also reduces sintering time by 12.31%and keeping temperature by 11.96%.This research provides new insights and methods for the preparation of ternary cathode materials.
基金supported by the National Natural Science Foundation of China(NSFC)(Nos.52078312,52478461,and 52408379)the Natural Science Foundation of Hebei Province(E2024210134)+2 种基金the Innovative Research Group Project of the Natural Science Foundation of Hebei Province(Grant No.E2021210099)CCCC Science and Technology R&D Project(Grant No.2021-ZJKJ-01)the S&T Program of Hebei(Grant No.225A0802D).
文摘During the thawing process of a railway subgrade,bidirectional thawing complicates water-heat transfer,leading to serious thaw settlement issues under train loads.Focusing on the severely frozen section of the Shuozhou-Huanghua port heavy-haul railway,this study conducted indoor soil-column laterally-limited compression tests on thawing fine-grained soil specimens to analyze the cumulative deformation during thawing.The deformation evolution was examined from both macroscopic and microscopic perspectives.The test results revealed a sig-nificant increase in the water content at the frozen interlayer during thawing,with minimal thaw settlement under no-load conditions.However,under dynamic loads,the thawing soil exhibited rapid settlement during the initial stages of the process.Increasing the dynamic load amplitude did not result in significant additional thaw settlement compression.Particle image velocimetry revealed substantial thaw settlement and compression at the top of thawing soil.Microscopically,the porosity at the top of the specimens significantly decreased,whereas the porosity in the frozen interlayer remained largely unchanged.Under dynamic loading,the specimens exhibited a concentrated distribution of large pores with scattered smaller pores.The phase change from ice to water,combined with dynamic loading,induced particle movement and expanded the inter-particle pore space,leading to macroscopic thaw settlement and soil compression.The findings can provide a theoretical foundation for maintaining and ensuring the safety of railway subgrades in cold regions.
基金the Natural Sciences and Engineering Research Council of Canada(NSERC)for funding this researchThis research used a high temperature confocal laser scanning microscope-VL2000DX-SVF17SP funded by Canada Foundation for Innovation John Evans Leaders Fund(CFI JELF,Project Number:32826),a PANalytical X’Pert diffraction instrument located at the Centre for crystal growth,Brockhouse Institute for Materials Research,and a scanning electron microscope-JEOL 6610 located at the Canadian Centre for Electron Microscopy at McMaster University.W.Mu would like to acknowledge Swedish Iron and Steel Research Office(Jernkonteret),STINT and SSF for supporting the time for international collaboration research regarding clean steel.
文摘Dissolution kinetics of CaO·2Al_(2)O_(3)(CA_(2))particles in a synthetic CaO-Al_(2)O_(3)-SiO_(2)steelmaking slag system have been investigated using the high-temperature confocal laser scanning microscope.Effects of temperature(i.e.,1500,1550,and 1600℃)and slag composition on the dissolution time of CA_(2)particles are investigated,along with the time dependency of the projection area of the particle during the dissolution process.It is found that the dissolution rate was enhanced by either an increase in temperature or a decrease in slag viscosity.Moreover,a higher ratio of CaO/Al_(2)O_(3)(C/A)leads to an increased dissolution rate of CA_(2)particle at 1600℃.Thermodynamic calculations suggested the dissolution product,i.e.,melilite,formed on the surface of the CA_(2)particle during dissolution in slag with a C/A ratio of 3.8 at 1550℃.Scanning electron microscopy equipped with energy dispersive X-ray spectrometry analysis of as-quenched samples confirmed the dissolution path of CA_(2)particles in slags with C/A ratios of 1.8 and 3.8 as well as the melilite formed on the surface of CA_(2)particle.The formation of this layer during the dissolution process was identified as a hindrance,impeding the dissolution of CA_(2)particle.A valuable reference for designing or/and choosing the composition of top slag for clean steel production is provided,especially using calcium treatment during the secondary refining process.
基金Supported by Scientific Research Program of Guangxi University of Chinese Medicine(P200246).
文摘[Objectives] To identify Pyrostegia venusta (Ker-Gawler.) Miers by microscope and ultraviolet spectrum. [Methods] The paraffin section, slide section and freehand section were used to make the cross section of the stem and leaf, and the surface of the leaf and the powder of the root, stem and leaf were made by the conventional method, which were observed under the optical microscope. Ultraviolet-visible spectrum identification was carried out according to a conventional method. [Results] The microscopic identification and ultraviolet-visible absorption characteristics of P. venusta (Ker-Gawler) Miers were described in detail. [Conclusions] This study is expected to provide a reference for the identification of P. venusta(KerGawler)Miers and the establishment of the related quality standard.
基金supported by the National Natural Science Foundation of China(Grant No.42377154)Henan Provincial Department of Science and Technology(Grant No.232102321009).
文摘The excellent bonding performance between bolt and anchor materials is crucial for controlling the deformation of deep-buried surrounding rock and strengthening the rock and soil mass in the slope.This paper conducted an anchoring test and ABAQUS numerical simulation of an anchoring system comprising a micro-NPR(microscopic negative Poisson’s ratio)bolt and cement mortar as the anchoring material.The failure mode of this system and the distribution of average bonding strength,axial force,and shear stress along the anchoring depth were studied.We also evaluated the bonding properties at the micro-NPR(microscopic negative Poisson’s ratio)bolt-cement mortar interface.The findings indicate that the cement mortar is partially spalled from the micro-NPR bolt surface.The average bonding strength at the micro-NPR bolt-cement mortar interface is positively correlated with anchoring length and cement mortar strength.In contrast,it exhibits a negative correlation with bolt diameter.The axial force is generated at the starting point of the anchorage and decreases non-uniformly across the anchoring region.The axial force transfers or diffuses toward the deeper sections of the anchoring segment with increasing loads.The shear stress at the micro-NPR bolt-cement mortar interface exhibits a single-peak pattern,i.e.,it climbs to a peak value and decreases along the anchoring depth.The peak position varies with changes in bolt diameter and anchoring length.By comparison,it is independent of cement mortar strength.The simulated bonding properties of the micro-NPR bolt-cement mortar interface are consistent with experimental results.The findings can provide a reference for engineering applications and anchoring design of micro-NPR.
