Vaginal delivery is a fascinating physiological process,but also a high-risk process.Up to 85%–90%of vaginal deliveries lead to perineal trauma,with nearly 11%of severe perineal tearing.It is a common occurrence,espe...Vaginal delivery is a fascinating physiological process,but also a high-risk process.Up to 85%–90%of vaginal deliveries lead to perineal trauma,with nearly 11%of severe perineal tearing.It is a common occurrence,especially for first-time mothers.Computational childbirth plays an essential role in the prediction and prevention of these traumas,but fast personalization of the pelvis and floor muscles is challenging due to their anatomical complexity.This study introduces a novel shape-prediction-based personalization of the pelvis and floor muscles for perineal tearing management and childbirth simulation.300 subjects were selected from public Computed Tomography(CT)databases.The pelvic bone nmjmeshes were generated using a coarse-to-fine non-rigid mesh alignment procedure.The floor muscle meshes were personalized using the bone mesh deformation information.A feature-to-pelvic structure reconstruction pipeline was proposed,incorporating various strategies.Ten-fold cross-validation helped determine the optimal reconstruction strategy,regression method,and feature sizes.The mesh-to-mesh distance metric was employed for evaluating.The statistical shape relation-based strategy,coupled with multi-output ridge regression,was the optimal approach for pelvic structure reconstruction.With a feature set ranging from 3 to 38,the mean errors were 2.672 to 1.613 mm,and 3.237 to 1.415 mm in muscle attachment regions.The best-and worst-case predictions had errors of 1.227±0.959 mm and 2.900±2.309 mm,respectively.This study provides a novel approach to achieving fast personalized childbirth modeling and simulation for perineal tearing management.展开更多
This article presents a detailed theoretical hybrid analysis of the magnetism and the thermal radiative heat transfer in the presence of heat generation affecting the behavior of the dispersed gold nanoparticles(AuNPs...This article presents a detailed theoretical hybrid analysis of the magnetism and the thermal radiative heat transfer in the presence of heat generation affecting the behavior of the dispersed gold nanoparticles(AuNPs)through the blood vessels of the human body.The rheology of gold-blood nanofluid is treated as magnetohydrodynamic(MHD)flow with ferromagnetic properties.The AuNPs take different shapes as bricks,cylinders,and platelets which are considered in changing the nanofluid flow behavior.Physiologically,the blood is circulated under the kinetics of the peristaltic action.The mixed properties of the slip flow,the gravity,the space porosity,the transverse ferromagnetic field,the thermal radiation,the nanoparticles shape factors,the peristaltic amplitude ratio,and the concentration of the AuNPs are interacted and analyzed for the gold-blood circulation in the inclined tube.The appropriate model for the thermal conductivity of the nanofluid is chosen to be the effective Hamilton-Crosser model.The undertaken nanofluid can be treated as incompressible non-Newtonian ferromagnetic fluid.The solutions of the partial differential governing equations of the MHD nanofluid flow are executed by the strategy of perturbation approach under the assumption of long wavelength and low Reynolds number.Graphs for the streamwise velocity distributions,temperature distributions,pressure gradients,pressure drops,and streamlines are presented under the influences of the pertinent properties.The practical implementation of this research finds application in treating cancer through a technique known as photothermal therapy(PTT).The results indicate the control role of the magnetism,the heat generation,the shape factors of the AuNPs,and its concentration on the enhancement of the thermal properties and the streamwise velocity of the nanofluid.The results reveal a marked enhancement in the temperature profiles of the nanofluid,prominently influenced by both the intensified heat source and the heightened volume fractions of the nanoparticles.Furthermore,the platelet shape is regarded as most advantageous for heat conduction owing to its highest effective thermal conductivity.AuNPs proved strong efficiency in delivering and targeting the drug to reach the affected area with tumors.These results offer valuable insights into evaluating the effectiveness of PTT in addressing diverse cancer conditions and regulating their progression.展开更多
Avian wings are central to their remarkable flight ability and diverse life history strategies,including behaviors such as fighting and mating.These multifaceted functions are intricately tied to wing shape,which vari...Avian wings are central to their remarkable flight ability and diverse life history strategies,including behaviors such as fighting and mating.These multifaceted functions are intricately tied to wing shape,which varies significantly across species because of the complex interplay of evolutionary and ecological pressures.Many indices have been developed to quantify wing characteristics to facilitate the study and comparison of avian wing morphology across species.This study provides a comprehensive overview of existing quantitative methods for analyzing avian wing shapes.We then constructed a new quantification framework through the beta distribution,which can generate indices reflecting the shape of avian wings(center,dispersion,skewness,and kurtosis).Next,we used the flight feathers of 613 bird species to perform different quantitative analyses and explore the relationships between various wing shape quantification methods and life history traits,which serve as proxies for the selective forces shaping wing morphology.We find that the wing shape indices are more strongly associated with ecological variables than with morphological variables,especially for migration,habitat and territoriality.This research guides the selection of appropriate methods for wing shape analysis,contributing to a deeper understanding of avian morphology and its evolutionary drivers.展开更多
Hypoxia and aberrant activation of epidermal growth factor receptor(EGFR)are considered important features of various malignancies.However,whether hypoxia can directly trigger EGFR activation and its clinical implicat...Hypoxia and aberrant activation of epidermal growth factor receptor(EGFR)are considered important features of various malignancies.However,whether hypoxia can directly trigger EGFR activation and its clinical implications remain unclear.In this study,we demonstrated that in oral cancer,a typical hypoxic tumor,hypoxia can induce chronic but constitutive phosphorylation of wild-type EGFR in the absence of ligands.Oral cancer cell lines exhibit different EGFR phosphorylation responses to hypoxia.In hypoxic HN4 and HN6 cells,ubiquitination-mediated endocytosis,lysosomal sorting,and degradation lead to low levels of EGFR phosphorylation.However,in CAL-27 and HN30 cells,a novel HIF-1α-induced long noncoding RNA(lnc RNA),EUDAL,can compete with the E3 ligase/adaptor complex c-Cbl/Grb2 for binding to EGFR,stabilizing phosphorylated EGFR(p EGFR)and resulting in sustained activation of EGFR and its downstream STAT3/BNIP3 signaling.STAT3/BNIP3-mediated autophagy leads to antitumor drug resistance.A high EUDAL/EGFR/STAT3/autophagy pathway activation predicts poor response to chemotherapy in oral cancer patients.Collectively,hypoxia can induce noncanonical ligand-independent EGFR phosphorylation.High EUDAL expression facilitates sustained EGFR phosphorylation in hypoxic tumor cells and leads to autophagy-related drug resistance.展开更多
ObjectiveThe thesis aims at investigating the distribution and structural characteristics of various branches in canopy of Korla fragrant pear. MethodStatistic work and analysis were conducted on the numbers and distr...ObjectiveThe thesis aims at investigating the distribution and structural characteristics of various branches in canopy of Korla fragrant pear. MethodStatistic work and analysis were conducted on the numbers and distribution characteristics of various branches in each cubic lattice by using the canopy cellular method. ResultThe results showed that： The total number of scaffold branches of evacuation layered tree shape was 97, which mainly distributed in the lower layer and middle part of the canopy; the total number of scaffold branches of open-center tree shape was 94, which mainly distributed in the lower layer and middle part of the canopy. The total number of annual branches of evacuation layered tree shape was 3 920, which mainly distributed in the middle layer and outer part of the canopy; and the total number of annual branches of the open-center tree shape was 3 183, which mainly distributed in middle layer and outer part of the canopy. The total number of perennial branches of evacuation layered tree shape was 2 184, which mainly distributed in lower layer and outer part of the canopy; the total number of perennial branches of open-center tree shape was 1 444, which mainly distributed in middle layer and outer part of the canopy. ConclusionThe total number and the distribution positions of scaffold branches in the canopy of each tree shape were basically the same. The total numbers of annual branches of the two kinds of tree shapes were different, but the distribution positions were basically the same. The total numbers and the distribution positions of perennial branches in the canopy of the two kinds of tree shapes were different.展开更多
In recent years,the demand for synchronous acquisition of three-dimensional(3D)shape and col-or texture has surged in fields such as cultural heritage preservation and healthcare.Addressing this need,this paper propos...In recent years,the demand for synchronous acquisition of three-dimensional(3D)shape and col-or texture has surged in fields such as cultural heritage preservation and healthcare.Addressing this need,this paper proposes a novel method for simultaneous 3D shape and color texture capture.First,a linear model correlating camera exposure time with grayscale values is established.Through exposure time calibration,the projected red,green and blue(RGB)light and white-light grayscale values captured by a monochrome cam-era are aligned.Then,three sets of color fringes are projected onto the object to identify optimal pixels for 3D reconstruction.And,three pure-color patterns are projected to synthesize the color texture.Experimental res-ults show that this method effectively achieves synchronous 3D shape and color texture acquisition,offering high speed and precision,and avoids color crosstalk interference common in 3D reconstruction of colored ob-jects using a monochrome camera.展开更多
With the rural concealed communication cable as the study object, the shielding effectiveness of different slot shapes was analyzed by using LBEM （linear boundary element method）. The engineering example results sho...With the rural concealed communication cable as the study object, the shielding effectiveness of different slot shapes was analyzed by using LBEM （linear boundary element method）. The engineering example results showed that for twocore shielded cable, the coupling capacitance of trapezoid slots （asymmetric and symmetric） changed the most, followed by rectangular slots （asymmetric and symmetric）, and the changes of wedge slots were the smallest, but the change tenden- cies were consistent. In addition, with the increase of slot width of different slots, the coupling capacitance of tow-cored shielded cable showed small change.展开更多
Additive manufacturing(AM)technology has emerged as a viable solution for manufacturing complexshaped WC−Co cemented carbide products,thereby expanding their applications in industries such as resource mining,equipmen...Additive manufacturing(AM)technology has emerged as a viable solution for manufacturing complexshaped WC−Co cemented carbide products,thereby expanding their applications in industries such as resource mining,equipment manufacturing,and electronic information.This review provides a comprehensive summary of the progress of AM technology in WC−Co cemented carbides.The fundamental principles and classification of AM techniques are introduced,followed by a categorization and evaluation of the AM techniques for WC−Co cemented carbides.These techniques are classified as either direct AM technology(DAM)or indirect AM technology(IDAM),depending on their inclusion of post-processes like de-binding and sintering.Through an analysis of microstructure features,the most suitable AM route for WC−Co cemented carbide products with controllable microstructure is identified as the indirect AM technology,such as binder jet printing(BJP),which integrates AM with conventional powder metallurgy.展开更多
Oxidative magnetization has attracted great attention as an efficient strategy for modulating physiochemical properties of magnetic biochar.In this paper,a K_(2)FeO_(4)-involving hydrothermal oxidative magnetization w...Oxidative magnetization has attracted great attention as an efficient strategy for modulating physiochemical properties of magnetic biochar.In this paper,a K_(2)FeO_(4)-involving hydrothermal oxidative magnetization was explored to regulate multiple micro-structures for manufacture magnetic hydrochar(MHC)for Fenton-like degradation of tetracycline in aqueous solution.Diverse shapes of Fe_(3)O_(4) and nano zero-valent iron(nZVI)were doped with abundant oxygen containing groups and persistent free radicals(PFRs).Multiple catalysis sites including iron species,PFRs,oxygen containing groups,and graphite defects contributed to accelerate the Fenton-like degradation with synergistic effect.Notably,MHC achieved a tetracycline removal rate of 99% within 60 min at 50 mg/L,with a total organic carbon(TOC)removal rate of 35%.Furthermore,after four cycles of reuse,the degradation efficiency slightly decreased to 93%.This study highlights the potential of magnetic hydrochar with multiple catalytic sites in the effective and sustainable degradation of pollutants.展开更多
Accurate mechanical modeling is essential for robotic belt grinding(RBG), a process characterized by compliant contact mechanisms that make force prediction particularly challenging. However, existing mechanical model...Accurate mechanical modeling is essential for robotic belt grinding(RBG), a process characterized by compliant contact mechanisms that make force prediction particularly challenging. However, existing mechanical models predominantly focus on macroscale compliance while neglecting grain-scale compliant motion. Moreover, abrasive grains are typically idealized as regular shapes, overlooking the inherent stochasticity of real grain geometries. This study proposes a shapeequivalence method for modeling stochastic abrasive grains and develops a multiscale compliant force model for RBG. Specifically, an individual grain is represented as a polygonal pyramid with stochastic edges that is mathematically equivalent to a cone;this method unifies the treatment of grain geometries and streamlines the modeling process. The mathematical equivalence relationship for random grain shapes is further derived based on a grain-compliant contact model. By integrating grain geometric characteristics and progressive grain wear, an analytical mechanical model that captures both the static contact force and dynamic grinding force is established, thereby describing the transition from grain-workpiece compliant interaction to belt-workpiece elastic contact. Grinding experiments were conducted using abrasive belts with different grain shape distributions to validate the model. The results demonstrated reliable predictions of the tangential grinding force and its component characteristics. Additional analyses were performed to reveal how the tangential grinding force varies with wear time and grinding parameters.展开更多
Coal cinder is an abundant byproduct of the extensive consumption of coal in industrial production and daily life.Making full use of the cinder is conducive to a low-carbon economy.In this study,inspired by the burnin...Coal cinder is an abundant byproduct of the extensive consumption of coal in industrial production and daily life.Making full use of the cinder is conducive to a low-carbon economy.In this study,inspired by the burning of coal,a new method for constructing a silica-based composite porous material(SiO_(2)-CPM)was developed by combusting a siloxane-modified anthracite coal gel(CSiO_(2) gel).During this process,the combustion product was directly converted into a porous material,and the calorific value of the coal remained nearly unchanged(~98%of the original calorific value was retained),demonstrating the viability of this method for energy-efficient applications.The SiO_(2)-CPM exhibited an ultra-low thermal conductivity(0.036 W/(m·K)at room temperature),outperforming conventional insulation materials(e.g.,cotton~0.05 W/(m·K)).Additionally,it showed enhanced mechanical strength(fracture stress of 41.8 kPa)compared to the powder state of the coal cinder.Experimental results indicate that the amount of siloxane,structure-directing agent,and an acidic environment were critical for mechanical enhancement.The SiO_(2)-CPM showed good dimensional stability against thermal expansion and exhibited excellent thermal insulation and fire resistance even at 900℃.Meanwhile,the SiO_(2)-CPM with complex geometry could be easily fabricated using this method owing to the excellent shaping ability of the CSiO_(2) gel.Compared to conventional methods such as sol-gel synthesis or freeze-drying,this approach for fabricating SiO_(2)-CPM is simpler and cost-effective and allows the direct utilization of coal cinder post-combustion.展开更多
To address the challenges of rapid bit failure and high drilling costs associated with hard limestone in Sichuan Basin of China,we conducted rock-breaking experiments and simulations of shaped(cylindrical,ridge,and ch...To address the challenges of rapid bit failure and high drilling costs associated with hard limestone in Sichuan Basin of China,we conducted rock-breaking experiments and simulations of shaped(cylindrical,ridge,and chopper)cutters.Rock mechanics,drillability,and acoustic emission indentation tests revealed the drilling resistance characteristics of the limestone:average uniaxial compressive strength of 202.472 MPa,tensile strength of 7.092 MPa,and drillability of 7.866.We evaluated the performance differences between the shaped cutters before introducing an efficient and innovative finite-discrete-infinite element method(FDIEM)to establish an interaction model between the shaped cutters and limestone.The simulation results indicated the following:(1)The shaped cutters demonstrated superior rock-breaking performance compared to the traditional cylindrical cutter.(2)Compared with the cylindrical cutter,the ridge cutter yielded the lowest peak indentation force and mechanical specific energy,with reductions of 8.71%and 33.83%,respectively.This confirmed that the ridge cutter had the optimal tooth profile for the target formation.Its rock-breaking mechanism relied on the convex edges to induce localized high stress in the rock,which enabled efficient rock fragmentation via a plowing mode while mitigating frictional resistance from cuttings.(3)The novel chopper cutter with its secondary step surface exerted a buffering effect on the cuttings,thereby achieving high cutting stability.This study provides theoretical and technical support for the design of personalized drill bits and the acceleration of the rate of penetration(ROP)in deep hard rock formations.展开更多
Traffic sign detection is a critical component of driving systems.Single-stage network-based traffic sign detection algorithms,renowned for their fast detection speeds and high accuracy,have become the dominant approa...Traffic sign detection is a critical component of driving systems.Single-stage network-based traffic sign detection algorithms,renowned for their fast detection speeds and high accuracy,have become the dominant approach in current practices.However,in complex and dynamic traffic scenes,particularly with smaller traffic sign objects,challenges such as missed and false detections can lead to reduced overall detection accuracy.To address this issue,this paper proposes a detection algorithm that integrates edge and shape information.Recognizing that traffic signs have specific shapes and distinct edge contours,this paper introduces an edge feature extraction branch within the backbone network,enabling adaptive fusion with features of the same hierarchical level.Additionally,a shape prior convolution module is designed to replaces the first two convolutional modules of the backbone network,aimed at enhancing the model's perception ability for specific shape objects and reducing its sensitivity to background noise.The algorithm was evaluated on the CCTSDB and TT100k datasets,and compared to YOLOv8s,the mAP50 values increased by 3.0%and 10.4%,respectively,demonstrating the effectiveness of the proposed method in improving the accuracy of traffic sign detection.展开更多
The mechanical performance of exceedingly soft materials such as Ag is significantly influenced by various working conditions.Therefore,this study systematically investigates the effects of crack geometry,substrate cr...The mechanical performance of exceedingly soft materials such as Ag is significantly influenced by various working conditions.Therefore,this study systematically investigates the effects of crack geometry,substrate crystal orientation,and indenter shape on crack propagation.The mechanical response of Ag is analyzed using the quasi-continuum(QC)method.A pre-crack with a predefined depth and angle was introduced to initiate fracture behavior.The results show that when the pre-crack height is 50 A,the crack propagates rapidly as the imprint depth increases from0 to 7 A,grows steadily up to 15 A,and then accelerates sharply between 15 and 20 A.For other pre-crack heights,crack propagation occurs at a relatively faster rate.Substrates with[100],[010],and[001]crystal orientations promote crack extension,while the onset of plastic deformation(referred to as the yield point in this study)and the fracture strength both increase with increasing pre-crack height.The yield point,fracture strength,and stress intensity factors are highly sensitive to the pre-crack height.When the pre-crack angle is 90○,the fracture strength reaches its maximum of 0.2%higher than that of the uncracked sample-whereas at 0○,it reaches its minimum,still 53.8%higher than that of the uncracked sample.The sample model is conducted using AutoCAD software.The optimized quasicontinuum(QC)method is used to investigate the effects of different crack geometries,substrate crystal orientations,and indenter shapes on the crack extension of Ag material.Baskes and Dow(FBD)potential is borrowed to describe the interaction forces between Ag-Ag,Ni-Ag,and Ni-Ni.展开更多
基金funded by Vietnam National University Ho Chi Minh City(VNU-HCM)under grant number DS.C2025-28-06.
文摘Vaginal delivery is a fascinating physiological process,but also a high-risk process.Up to 85%–90%of vaginal deliveries lead to perineal trauma,with nearly 11%of severe perineal tearing.It is a common occurrence,especially for first-time mothers.Computational childbirth plays an essential role in the prediction and prevention of these traumas,but fast personalization of the pelvis and floor muscles is challenging due to their anatomical complexity.This study introduces a novel shape-prediction-based personalization of the pelvis and floor muscles for perineal tearing management and childbirth simulation.300 subjects were selected from public Computed Tomography(CT)databases.The pelvic bone nmjmeshes were generated using a coarse-to-fine non-rigid mesh alignment procedure.The floor muscle meshes were personalized using the bone mesh deformation information.A feature-to-pelvic structure reconstruction pipeline was proposed,incorporating various strategies.Ten-fold cross-validation helped determine the optimal reconstruction strategy,regression method,and feature sizes.The mesh-to-mesh distance metric was employed for evaluating.The statistical shape relation-based strategy,coupled with multi-output ridge regression,was the optimal approach for pelvic structure reconstruction.With a feature set ranging from 3 to 38,the mean errors were 2.672 to 1.613 mm,and 3.237 to 1.415 mm in muscle attachment regions.The best-and worst-case predictions had errors of 1.227±0.959 mm and 2.900±2.309 mm,respectively.This study provides a novel approach to achieving fast personalized childbirth modeling and simulation for perineal tearing management.
文摘This article presents a detailed theoretical hybrid analysis of the magnetism and the thermal radiative heat transfer in the presence of heat generation affecting the behavior of the dispersed gold nanoparticles(AuNPs)through the blood vessels of the human body.The rheology of gold-blood nanofluid is treated as magnetohydrodynamic(MHD)flow with ferromagnetic properties.The AuNPs take different shapes as bricks,cylinders,and platelets which are considered in changing the nanofluid flow behavior.Physiologically,the blood is circulated under the kinetics of the peristaltic action.The mixed properties of the slip flow,the gravity,the space porosity,the transverse ferromagnetic field,the thermal radiation,the nanoparticles shape factors,the peristaltic amplitude ratio,and the concentration of the AuNPs are interacted and analyzed for the gold-blood circulation in the inclined tube.The appropriate model for the thermal conductivity of the nanofluid is chosen to be the effective Hamilton-Crosser model.The undertaken nanofluid can be treated as incompressible non-Newtonian ferromagnetic fluid.The solutions of the partial differential governing equations of the MHD nanofluid flow are executed by the strategy of perturbation approach under the assumption of long wavelength and low Reynolds number.Graphs for the streamwise velocity distributions,temperature distributions,pressure gradients,pressure drops,and streamlines are presented under the influences of the pertinent properties.The practical implementation of this research finds application in treating cancer through a technique known as photothermal therapy(PTT).The results indicate the control role of the magnetism,the heat generation,the shape factors of the AuNPs,and its concentration on the enhancement of the thermal properties and the streamwise velocity of the nanofluid.The results reveal a marked enhancement in the temperature profiles of the nanofluid,prominently influenced by both the intensified heat source and the heightened volume fractions of the nanoparticles.Furthermore,the platelet shape is regarded as most advantageous for heat conduction owing to its highest effective thermal conductivity.AuNPs proved strong efficiency in delivering and targeting the drug to reach the affected area with tumors.These results offer valuable insights into evaluating the effectiveness of PTT in addressing diverse cancer conditions and regulating their progression.
基金supported by the National Natural Science Foundation of China(No.32170491)the Scientific Research Team Project of the College of Life Sciences,Beijing Normal University in 2024。
文摘Avian wings are central to their remarkable flight ability and diverse life history strategies,including behaviors such as fighting and mating.These multifaceted functions are intricately tied to wing shape,which varies significantly across species because of the complex interplay of evolutionary and ecological pressures.Many indices have been developed to quantify wing characteristics to facilitate the study and comparison of avian wing morphology across species.This study provides a comprehensive overview of existing quantitative methods for analyzing avian wing shapes.We then constructed a new quantification framework through the beta distribution,which can generate indices reflecting the shape of avian wings(center,dispersion,skewness,and kurtosis).Next,we used the flight feathers of 613 bird species to perform different quantitative analyses and explore the relationships between various wing shape quantification methods and life history traits,which serve as proxies for the selective forces shaping wing morphology.We find that the wing shape indices are more strongly associated with ecological variables than with morphological variables,especially for migration,habitat and territoriality.This research guides the selection of appropriate methods for wing shape analysis,contributing to a deeper understanding of avian morphology and its evolutionary drivers.
基金supported by the National Natural Science Foundation of China(82273095,82203614)the Shanghai Sailing Program(22YF1421600)。
文摘Hypoxia and aberrant activation of epidermal growth factor receptor(EGFR)are considered important features of various malignancies.However,whether hypoxia can directly trigger EGFR activation and its clinical implications remain unclear.In this study,we demonstrated that in oral cancer,a typical hypoxic tumor,hypoxia can induce chronic but constitutive phosphorylation of wild-type EGFR in the absence of ligands.Oral cancer cell lines exhibit different EGFR phosphorylation responses to hypoxia.In hypoxic HN4 and HN6 cells,ubiquitination-mediated endocytosis,lysosomal sorting,and degradation lead to low levels of EGFR phosphorylation.However,in CAL-27 and HN30 cells,a novel HIF-1α-induced long noncoding RNA(lnc RNA),EUDAL,can compete with the E3 ligase/adaptor complex c-Cbl/Grb2 for binding to EGFR,stabilizing phosphorylated EGFR(p EGFR)and resulting in sustained activation of EGFR and its downstream STAT3/BNIP3 signaling.STAT3/BNIP3-mediated autophagy leads to antitumor drug resistance.A high EUDAL/EGFR/STAT3/autophagy pathway activation predicts poor response to chemotherapy in oral cancer patients.Collectively,hypoxia can induce noncanonical ligand-independent EGFR phosphorylation.High EUDAL expression facilitates sustained EGFR phosphorylation in hypoxic tumor cells and leads to autophagy-related drug resistance.
基金Supported by National Department Public Benefit Research Foundation(201304701-4)Science and Technology Planning Program of Xinjiang Uygur Autonomous RegionXinjiang Uygur Autonomous Region Fruit Major Subjects~~
文摘ObjectiveThe thesis aims at investigating the distribution and structural characteristics of various branches in canopy of Korla fragrant pear. MethodStatistic work and analysis were conducted on the numbers and distribution characteristics of various branches in each cubic lattice by using the canopy cellular method. ResultThe results showed that： The total number of scaffold branches of evacuation layered tree shape was 97, which mainly distributed in the lower layer and middle part of the canopy; the total number of scaffold branches of open-center tree shape was 94, which mainly distributed in the lower layer and middle part of the canopy. The total number of annual branches of evacuation layered tree shape was 3 920, which mainly distributed in the middle layer and outer part of the canopy; and the total number of annual branches of the open-center tree shape was 3 183, which mainly distributed in middle layer and outer part of the canopy. The total number of perennial branches of evacuation layered tree shape was 2 184, which mainly distributed in lower layer and outer part of the canopy; the total number of perennial branches of open-center tree shape was 1 444, which mainly distributed in middle layer and outer part of the canopy. ConclusionThe total number and the distribution positions of scaffold branches in the canopy of each tree shape were basically the same. The total numbers of annual branches of the two kinds of tree shapes were different, but the distribution positions were basically the same. The total numbers and the distribution positions of perennial branches in the canopy of the two kinds of tree shapes were different.
文摘In recent years,the demand for synchronous acquisition of three-dimensional(3D)shape and col-or texture has surged in fields such as cultural heritage preservation and healthcare.Addressing this need,this paper proposes a novel method for simultaneous 3D shape and color texture capture.First,a linear model correlating camera exposure time with grayscale values is established.Through exposure time calibration,the projected red,green and blue(RGB)light and white-light grayscale values captured by a monochrome cam-era are aligned.Then,three sets of color fringes are projected onto the object to identify optimal pixels for 3D reconstruction.And,three pure-color patterns are projected to synthesize the color texture.Experimental res-ults show that this method effectively achieves synchronous 3D shape and color texture acquisition,offering high speed and precision,and avoids color crosstalk interference common in 3D reconstruction of colored ob-jects using a monochrome camera.
基金Supported by the Science and Technology Program of the Education Department of Shaanxi Provincial Government(09JK378)the Key Scientific Research Fund of Shaanxi University of Technology(SLGKY12-02)~~
文摘With the rural concealed communication cable as the study object, the shielding effectiveness of different slot shapes was analyzed by using LBEM （linear boundary element method）. The engineering example results showed that for twocore shielded cable, the coupling capacitance of trapezoid slots （asymmetric and symmetric） changed the most, followed by rectangular slots （asymmetric and symmetric）, and the changes of wedge slots were the smallest, but the change tenden- cies were consistent. In addition, with the increase of slot width of different slots, the coupling capacitance of tow-cored shielded cable showed small change.
基金supported by Major Science and Technology Projects in Fujian Province,China(No.2023HZ021005)State Key Laboratory of Powder Metallurgy,Central South University,ChinaFujian Key Laboratory of Rare-earth Functional Materials,China。
文摘Additive manufacturing(AM)technology has emerged as a viable solution for manufacturing complexshaped WC−Co cemented carbide products,thereby expanding their applications in industries such as resource mining,equipment manufacturing,and electronic information.This review provides a comprehensive summary of the progress of AM technology in WC−Co cemented carbides.The fundamental principles and classification of AM techniques are introduced,followed by a categorization and evaluation of the AM techniques for WC−Co cemented carbides.These techniques are classified as either direct AM technology(DAM)or indirect AM technology(IDAM),depending on their inclusion of post-processes like de-binding and sintering.Through an analysis of microstructure features,the most suitable AM route for WC−Co cemented carbide products with controllable microstructure is identified as the indirect AM technology,such as binder jet printing(BJP),which integrates AM with conventional powder metallurgy.
基金supported byHainan Provincial Natural Science Foundation of China(Nos.422RC600,519QN175)National Natural Science Foundation ofChina(Nos.52160018,21801053,52400206,52500209)High-Level Talent Program of Hainan Province(Nos.XJ2400008202,XJ2400011473).
文摘Oxidative magnetization has attracted great attention as an efficient strategy for modulating physiochemical properties of magnetic biochar.In this paper,a K_(2)FeO_(4)-involving hydrothermal oxidative magnetization was explored to regulate multiple micro-structures for manufacture magnetic hydrochar(MHC)for Fenton-like degradation of tetracycline in aqueous solution.Diverse shapes of Fe_(3)O_(4) and nano zero-valent iron(nZVI)were doped with abundant oxygen containing groups and persistent free radicals(PFRs).Multiple catalysis sites including iron species,PFRs,oxygen containing groups,and graphite defects contributed to accelerate the Fenton-like degradation with synergistic effect.Notably,MHC achieved a tetracycline removal rate of 99% within 60 min at 50 mg/L,with a total organic carbon(TOC)removal rate of 35%.Furthermore,after four cycles of reuse,the degradation efficiency slightly decreased to 93%.This study highlights the potential of magnetic hydrochar with multiple catalytic sites in the effective and sustainable degradation of pollutants.
基金supported by the National Natural Science Foundation of China (Grant Nos.52505554,52575571)the Postdoctoral Fellowship Program of CPSF (Grant No.GZB20250348)。
文摘Accurate mechanical modeling is essential for robotic belt grinding(RBG), a process characterized by compliant contact mechanisms that make force prediction particularly challenging. However, existing mechanical models predominantly focus on macroscale compliance while neglecting grain-scale compliant motion. Moreover, abrasive grains are typically idealized as regular shapes, overlooking the inherent stochasticity of real grain geometries. This study proposes a shapeequivalence method for modeling stochastic abrasive grains and develops a multiscale compliant force model for RBG. Specifically, an individual grain is represented as a polygonal pyramid with stochastic edges that is mathematically equivalent to a cone;this method unifies the treatment of grain geometries and streamlines the modeling process. The mathematical equivalence relationship for random grain shapes is further derived based on a grain-compliant contact model. By integrating grain geometric characteristics and progressive grain wear, an analytical mechanical model that captures both the static contact force and dynamic grinding force is established, thereby describing the transition from grain-workpiece compliant interaction to belt-workpiece elastic contact. Grinding experiments were conducted using abrasive belts with different grain shape distributions to validate the model. The results demonstrated reliable predictions of the tangential grinding force and its component characteristics. Additional analyses were performed to reveal how the tangential grinding force varies with wear time and grinding parameters.
基金supported by the National Natural Science Foundation of China(No.52573220)the National Key R&D Program of China(No.2023YFC3404201)+1 种基金the Fundamental Research Funds for the Central Universities(No.FRF-IDRY-GD24-005)the State Key Laboratory of Solid Waste Reuse for Building Materials(No.SWR-2022-009).
文摘Coal cinder is an abundant byproduct of the extensive consumption of coal in industrial production and daily life.Making full use of the cinder is conducive to a low-carbon economy.In this study,inspired by the burning of coal,a new method for constructing a silica-based composite porous material(SiO_(2)-CPM)was developed by combusting a siloxane-modified anthracite coal gel(CSiO_(2) gel).During this process,the combustion product was directly converted into a porous material,and the calorific value of the coal remained nearly unchanged(~98%of the original calorific value was retained),demonstrating the viability of this method for energy-efficient applications.The SiO_(2)-CPM exhibited an ultra-low thermal conductivity(0.036 W/(m·K)at room temperature),outperforming conventional insulation materials(e.g.,cotton~0.05 W/(m·K)).Additionally,it showed enhanced mechanical strength(fracture stress of 41.8 kPa)compared to the powder state of the coal cinder.Experimental results indicate that the amount of siloxane,structure-directing agent,and an acidic environment were critical for mechanical enhancement.The SiO_(2)-CPM showed good dimensional stability against thermal expansion and exhibited excellent thermal insulation and fire resistance even at 900℃.Meanwhile,the SiO_(2)-CPM with complex geometry could be easily fabricated using this method owing to the excellent shaping ability of the CSiO_(2) gel.Compared to conventional methods such as sol-gel synthesis or freeze-drying,this approach for fabricating SiO_(2)-CPM is simpler and cost-effective and allows the direct utilization of coal cinder post-combustion.
基金the National Science and Technology Major Project(Grant No.2025ZD1008300)the Major Scientific Research Instrument Development Project of the National Natural Science Foundation of China(Grant No.52327803).
文摘To address the challenges of rapid bit failure and high drilling costs associated with hard limestone in Sichuan Basin of China,we conducted rock-breaking experiments and simulations of shaped(cylindrical,ridge,and chopper)cutters.Rock mechanics,drillability,and acoustic emission indentation tests revealed the drilling resistance characteristics of the limestone:average uniaxial compressive strength of 202.472 MPa,tensile strength of 7.092 MPa,and drillability of 7.866.We evaluated the performance differences between the shaped cutters before introducing an efficient and innovative finite-discrete-infinite element method(FDIEM)to establish an interaction model between the shaped cutters and limestone.The simulation results indicated the following:(1)The shaped cutters demonstrated superior rock-breaking performance compared to the traditional cylindrical cutter.(2)Compared with the cylindrical cutter,the ridge cutter yielded the lowest peak indentation force and mechanical specific energy,with reductions of 8.71%and 33.83%,respectively.This confirmed that the ridge cutter had the optimal tooth profile for the target formation.Its rock-breaking mechanism relied on the convex edges to induce localized high stress in the rock,which enabled efficient rock fragmentation via a plowing mode while mitigating frictional resistance from cuttings.(3)The novel chopper cutter with its secondary step surface exerted a buffering effect on the cuttings,thereby achieving high cutting stability.This study provides theoretical and technical support for the design of personalized drill bits and the acceleration of the rate of penetration(ROP)in deep hard rock formations.
基金supported by the National Natural Science Foundation of China(Grant Nos.62572057,62272049,U24A20331)Beijing Natural Science Foundation(Grant Nos.4232026,4242020)Academic Research Projects of Beijing Union University(Grant No.ZK10202404).
文摘Traffic sign detection is a critical component of driving systems.Single-stage network-based traffic sign detection algorithms,renowned for their fast detection speeds and high accuracy,have become the dominant approach in current practices.However,in complex and dynamic traffic scenes,particularly with smaller traffic sign objects,challenges such as missed and false detections can lead to reduced overall detection accuracy.To address this issue,this paper proposes a detection algorithm that integrates edge and shape information.Recognizing that traffic signs have specific shapes and distinct edge contours,this paper introduces an edge feature extraction branch within the backbone network,enabling adaptive fusion with features of the same hierarchical level.Additionally,a shape prior convolution module is designed to replaces the first two convolutional modules of the backbone network,aimed at enhancing the model's perception ability for specific shape objects and reducing its sensitivity to background noise.The algorithm was evaluated on the CCTSDB and TT100k datasets,and compared to YOLOv8s,the mAP50 values increased by 3.0%and 10.4%,respectively,demonstrating the effectiveness of the proposed method in improving the accuracy of traffic sign detection.
基金by the Industry–Academia Cooperation Project No.113A00262(Te-Hua Fang).URLs to the sponsor websites are available at:https://www.nstc.gov.tw.
文摘The mechanical performance of exceedingly soft materials such as Ag is significantly influenced by various working conditions.Therefore,this study systematically investigates the effects of crack geometry,substrate crystal orientation,and indenter shape on crack propagation.The mechanical response of Ag is analyzed using the quasi-continuum(QC)method.A pre-crack with a predefined depth and angle was introduced to initiate fracture behavior.The results show that when the pre-crack height is 50 A,the crack propagates rapidly as the imprint depth increases from0 to 7 A,grows steadily up to 15 A,and then accelerates sharply between 15 and 20 A.For other pre-crack heights,crack propagation occurs at a relatively faster rate.Substrates with[100],[010],and[001]crystal orientations promote crack extension,while the onset of plastic deformation(referred to as the yield point in this study)and the fracture strength both increase with increasing pre-crack height.The yield point,fracture strength,and stress intensity factors are highly sensitive to the pre-crack height.When the pre-crack angle is 90○,the fracture strength reaches its maximum of 0.2%higher than that of the uncracked sample-whereas at 0○,it reaches its minimum,still 53.8%higher than that of the uncracked sample.The sample model is conducted using AutoCAD software.The optimized quasicontinuum(QC)method is used to investigate the effects of different crack geometries,substrate crystal orientations,and indenter shapes on the crack extension of Ag material.Baskes and Dow(FBD)potential is borrowed to describe the interaction forces between Ag-Ag,Ni-Ag,and Ni-Ni.
