Dysphagia is commonly associated with malnutrition and an increased choking risk.To overcome these complications,food designed for people with dysphagia should have an appropriate texture and a high nutritional value....Dysphagia is commonly associated with malnutrition and an increased choking risk.To overcome these complications,food designed for people with dysphagia should have an appropriate texture and a high nutritional value.In this study,six formulations of a strawberry dessert enriched in protein(calcium caseinate)and fiber(wheat dextrin or inulin)were developed using different hydrocolloids(xanthan gum,carboxymethyl cellulose or modified starch)to provide desirable texture and stability.Nutritional value was calculated and total phenolic content and antioxidant activity of the samples were analyzed.Back-extrusion test,rheological measurements and sensory analysis were performed in refrigerated and frozen samples to characterize their textural and viscoelastic properties.The high content in protein(14.7 g/100 g)and fiber(7.9-8.7 g/100 g)made possible to use the claims“high protein”and“high fiber”.Phytochemicals supplied by strawberries contributed to the antioxidant properties of the dessert.Loss tangent ranged 0.28-0.35 for all the formulations,indicating a weak gel behavior,which could be considered safe to swallow.The formulations with dextrin in combination with carboxymethyl cellulose or xanthan gum seemed to be less susceptible to structural changes during frozen storage.This work provides insights for the development of a nutrient-dense dessert that meets the requirements of people with dysphagia.展开更多
Manual investigation of chest radiography(CXR)images by physicians is crucial for effective decision-making in COVID-19 diagnosis.However,the high demand during the pandemic necessitates auxiliary help through image a...Manual investigation of chest radiography(CXR)images by physicians is crucial for effective decision-making in COVID-19 diagnosis.However,the high demand during the pandemic necessitates auxiliary help through image analysis and machine learning techniques.This study presents a multi-threshold-based segmentation technique to probe high pixel intensity regions in CXR images of various pathologies,including normal cases.Texture information is extracted using gray co-occurrence matrix(GLCM)-based features,while vessel-like features are obtained using Frangi,Sato,and Meijering filters.Machine learning models employing Decision Tree(DT)and RandomForest(RF)approaches are designed to categorize CXR images into common lung infections,lung opacity(LO),COVID-19,and viral pneumonia(VP).The results demonstrate that the fusion of texture and vesselbased features provides an effective ML model for aiding diagnosis.The ML model validation using performance measures,including an accuracy of approximately 91.8%with an RF-based classifier,supports the usefulness of the feature set and classifier model in categorizing the four different pathologies.Furthermore,the study investigates the importance of the devised features in identifying the underlying pathology and incorporates histogrambased analysis.This analysis reveals varying natural pixel distributions in CXR images belonging to the normal,COVID-19,LO,and VP groups,motivating the incorporation of additional features such as mean,standard deviation,skewness,and percentile based on the filtered images.Notably,the study achieves a considerable improvement in categorizing COVID-19 from LO,with a true positive rate of 97%,further substantiating the effectiveness of the methodology implemented.展开更多
Olympus Corporation developed texture and color enhancement imaging(TXI)as a novel image-enhancing endoscopic technique.This topic highlights a series of hot-topic articles that investigated the efficacy of TXI for ga...Olympus Corporation developed texture and color enhancement imaging(TXI)as a novel image-enhancing endoscopic technique.This topic highlights a series of hot-topic articles that investigated the efficacy of TXI for gastrointestinal disease identification in the clinical setting.A randomized controlled trial demonstrated improvements in the colorectal adenoma detection rate(ADR)and the mean number of adenomas per procedure(MAP)of TXI compared with those of white-light imaging(WLI)observation(58.7%vs 42.7%,adjusted relative risk 1.35,95%CI:1.17-1.56;1.36 vs 0.89,adjusted incident risk ratio 1.48,95%CI:1.22-1.80,respectively).A cross-over study also showed that the colorectal MAP and ADR in TXI were higher than those in WLI(1.5 vs 1.0,adjusted odds ratio 1.4,95%CI:1.2-1.6;58.2%vs 46.8%,1.5,1.0-2.3,respectively).A randomized controlled trial demonstrated non-inferiority of TXI to narrow-band imaging in the colorectal mean number of adenomas and sessile serrated lesions per procedure(0.29 vs 0.30,difference for non-inferiority-0.01,95%CI:-0.10 to 0.08).A cohort study found that scoring for ulcerative colitis severity using TXI could predict relapse of ulcerative colitis.A cross-sectional study found that TXI improved the gastric cancer detection rate compared to WLI(0.71%vs 0.29%).A cross-sectional study revealed that the sensitivity and accuracy for active Helicobacter pylori gastritis in TXI were higher than those of WLI(69.2%vs 52.5%and 85.3%vs 78.7%,res-pectively).In conclusion,TXI can improve gastrointestinal lesion detection and qualitative diagnosis.Therefore,further studies on the efficacy of TXI in clinical practice are required.展开更多
BACKGROUND Despite continuous changes in treatment methods,the survival rate for advanced hepatocellular carcinoma(HCC)patients remains low,highlighting the importance of diagnostic methods for HCC.AIM To explore the ...BACKGROUND Despite continuous changes in treatment methods,the survival rate for advanced hepatocellular carcinoma(HCC)patients remains low,highlighting the importance of diagnostic methods for HCC.AIM To explore the efficacy of texture analysis based on multi-parametric magnetic resonance(MR)imaging(MRI)in predicting microvascular invasion(MVI)in preoperative HCC.METHODS This study included 105 patients with pathologically confirmed HCC,categorized into MVI-positive and MVI-negative groups.We employed Original Data Analysis,Principal Component Analysis,Linear Discriminant Analysis(LDA),and Non-LDA(NDA)for texture analysis using multi-parametric MR images to predict preoperative MVI.The effectiveness of texture analysis was determined using the B11 program of the MaZda4.6 software,with results expressed as the misjudgment rate(MCR).RESULTS Texture analysis using multi-parametric MRI,particularly the MI+PA+F dimensionality reduction method combined with NDA discrimination,demonstrated the most effective prediction of MVI in HCC.Prediction accuracy in the pulse and equilibrium phases was 83.81%.MCRs for the combination of T2-weighted imaging(T2WI),arterial phase,portal venous phase,and equilibrium phase were 22.86%,16.19%,20.95%,and 20.95%,respectively.The area under the curve for predicting MVI positivity was 0.844,with a sensitivity of 77.19%and specificity of 91.67%.CONCLUSION Texture analysis of arterial phase images demonstrated superior predictive efficacy for MVI in HCC compared to T2WI,portal venous,and equilibrium phases.This study provides an objective,non-invasive method for preoperative prediction of MVI,offering a theoretical foundation for the selection of clinical therapy.展开更多
Cutting tools are known as the“productivity”of the manufacturing industry,which affects the production efficiency and quality of the workpiece,and has become the focus of research and attention in academia and indus...Cutting tools are known as the“productivity”of the manufacturing industry,which affects the production efficiency and quality of the workpiece,and has become the focus of research and attention in academia and industry.However,traditional cutting tools often suffer from adhesion or wear during the cutting process,which considerably reduces the cutting efficiency and service life of the tools,and makes it difficult to meet current production requirements.To solve the above problems,scholars have introduced bionics into the tool’s design,applying the microscopic structure of the biological surface to the tool surface to alleviate the tool’s failure.This paper mainly summarizes the research progress of bionic textured cutting tools.Firstly,categorize whether the bionic texture design is inspired by a single organism or multiple organisms.Secondly,it is discussed that the non-smooth surface of the biological surface has five characteristics:hydrophilic lubricity,wear resistance,drag reduction and hydrophobicity,anti-adhesion,and arrangement,and the non-smooth structure of these different characteristics are applied to the surface of the tool is designed with bionic texture.Furtherly,the cutting performance of bionic textured cutting tools is discussed.The anti-friction and wear-resisting mechanism of bionic textured cutting tools is analyzed.Finally,some pending problems and perspectives have been proposed to provide new inspirations for the design of bionic textured cutting tools.展开更多
Purpose: This review examines the diagnostic value of transvaginal 3D ultrasound image texture analysis for the diagnosis of uterine adhesions. Materials and Methods: The total clinical data of 53 patients with uterin...Purpose: This review examines the diagnostic value of transvaginal 3D ultrasound image texture analysis for the diagnosis of uterine adhesions. Materials and Methods: The total clinical data of 53 patients with uterine adhesions diagnosed by hysteroscopy and the imaging data of transvaginal three-dimensional ultrasound from the Second Affiliated Hospital of Chongqing Medical University from June 2022 to August 2023 were retrospectively analysed. Based on hysteroscopic surgical records, patients were divided into two independent groups: normal endometrium and uterine adhesion sites. The samples were divided into a training set and a test set, and the transvaginal 3D ultrasound was used to outline the region of interest (ROI) and extract texture features for normal endometrium and uterine adhesions based on hysteroscopic surgical recordings, the training set data were feature screened and modelled using lasso regression and cross-validation, and the diagnostic efficacy of the model was assessed by applying the subjects’ operating characteristic (ROC) curves. Results: For each group, 290 texture feature parameters were extracted and three higher values were screened out, and the area under the curve of the constructed ultrasonographic scoring model was 0.658 and 0.720 in the training and test sets, respectively. Conclusion Relative clinical value of transvaginal three-dimensional ultrasound image texture analysis for the diagnosis of uterine adhesions.展开更多
The purpose of the research is to develop a universal algorithm for partial texture segmentation of any visual images. The main peculiarity of the proposed segmentation procedure is the extraction of only homogeneous ...The purpose of the research is to develop a universal algorithm for partial texture segmentation of any visual images. The main peculiarity of the proposed segmentation procedure is the extraction of only homogeneous fine-grained texture segments present in the images. At first, an initial seed point is found for the largest and most homogeneous segment of the image. This initial seed point of the segment is expanded using a region growing method. Other texture segments of the image are extracted analogously in turn. At the second stage, the procedure of merging the extracted segments belonging to the same texture class is performed. Then, the detected texture segments are input to a neural network with competitive layers which accomplishe</span><span style="font-family:Verdana;">s</span><span style="font-family:""><span style="font-family:Verdana;"> more accurate delineation of the shapes of the extracted texture segments. The proposed segmentation procedure is fully unsupervised, <i></span><i><span style="font-family:Verdana;">i.e.</span></i><span style="font-family:Verdana;"></i>, it does not use any a priori knowledge on either the type of textures or the number of texture segments in the image. The research results in development of the segmentation algorithm realized as a computer program tested in a series of experiments that demonstrate its efficiency on grayscale natural scenes.展开更多
Dual-phase Mg-Li alloys sheets were rolled at four different temperatures ranging from liquid nitrogen to 300℃to explore effect of rolling temperature on texture and mechanical properties of the material.Crystal plas...Dual-phase Mg-Li alloys sheets were rolled at four different temperatures ranging from liquid nitrogen to 300℃to explore effect of rolling temperature on texture and mechanical properties of the material.Crystal plasticity simulation was utilized to illustrate the influence of slip activity on rolling texture development.The results show that the rolling texture is largely depended on deformation temperature.Unlike commercial Mg alloys,the critical resolved shear stress of basal slip inα-Mg phase of Mg-Li alloy decreased more significantly by increasing temperature compared to that of pyramidal<c+a>slip.Enhancement of basal slip by increasing temperature triggered a decrease of split angle of basal poles for the double-peak texture.Prismaticslip largely enhanced by increasing temperature upon 200℃,which induced a wider orientation spread along the transverse direction.For theβ-Li phase,the promotion of{110}<111>slip system at elevated temperature triggered the enhancement of{211}<110>and{111}<211>texture components.The cryo-rolled sample exhibited the highest strength compared to the others due to a strong hardening behavior at this temperature.A two-stage hardening behavior was observed in these as-rolled dual-phase alloys.Strain transition at phase boundaries could be the reason for appearance of this two-stage hardening.展开更多
Laser powder bed fusion(LPBF)makes it possible for biodegradable zinc(Zn)to be used to produce customized orthopedic implants.In this research,we investigate the impact of laser power and scanning speed on the develop...Laser powder bed fusion(LPBF)makes it possible for biodegradable zinc(Zn)to be used to produce customized orthopedic implants.In this research,we investigate the impact of laser power and scanning speed on the development of surface quality,relative densification,and texture during LPBF of Zn implants.Increasing laser power was able to decrease melt viscosity and surface tension,which improved the metallurgical bonding between adjacent tracks.Uneven and twisted tracks also became continuous and straight.Scanning speed could controlmolten-pool temperature to restrain grain natural orientation,achieving various crystal orientations and a weakened texture.Importantly,it further avoided the thermal expansion and contraction caused by excessive energy storage and accumulation in the matrix,thus reducing the generation of high-dislocation density.As a result,by selecting a reasonable laser power and scanning speed,the LPBF parts exhibited a flat surface morphology and a high density over 99.5%.Their average hardness,mechanical strength,and elongation reached 50.2 HV,127.8 MPa,and 7.6%,respectively.Additionally,the parts displayed a moderate degradation rate and excellent osteogenic properties.All these results provide a basis for selecting process parameters to optimize the comprehensive properties of LPBF-processed Zn parts for biodegradable applications.展开更多
Around one in eight women will be diagnosed with breast cancer at some time.Improved patient outcomes necessitate both early detection and an accurate diagnosis.Histological images are routinely utilized in the proces...Around one in eight women will be diagnosed with breast cancer at some time.Improved patient outcomes necessitate both early detection and an accurate diagnosis.Histological images are routinely utilized in the process of diagnosing breast cancer.Methods proposed in recent research only focus on classifying breast cancer on specific magnification levels.No study has focused on using a combined dataset with multiple magnification levels to classify breast cancer.A strategy for detecting breast cancer is provided in the context of this investigation.Histopathology image texture data is used with the wavelet transform in this technique.The proposed method comprises converting histopathological images from Red Green Blue(RGB)to Chrominance of Blue and Chrominance of Red(YCBCR),utilizing a wavelet transform to extract texture information,and classifying the images with Extreme Gradient Boosting(XGBOOST).Furthermore,SMOTE has been used for resampling as the dataset has imbalanced samples.The suggested method is evaluated using 10-fold cross-validation and achieves an accuracy of 99.27%on the BreakHis 1.040X dataset,98.95%on the BreakHis 1.0100X dataset,98.92%on the BreakHis 1.0200X dataset,98.78%on the BreakHis 1.0400X dataset,and 98.80%on the combined dataset.The findings of this study imply that improved breast cancer detection rates and patient outcomes can be achieved by combining wavelet transformation with textural signals to detect breast cancer in histopathology images.展开更多
BACKGROUND Accurate diagnosis and early resection of colorectal polyps are important to prevent the occurrence of colorectal cancer.However,technical factors and morphological factors of polyps itself can lead to miss...BACKGROUND Accurate diagnosis and early resection of colorectal polyps are important to prevent the occurrence of colorectal cancer.However,technical factors and morphological factors of polyps itself can lead to missed diagnoses.Imageenhanced endoscopy and chromoendoscopy(CE)have been developed to facilitate an accurate diagnosis.There have been no reports on visibility using a combination of texture and color enhancement imaging(TXI)and CE for colorectal tumors.AIM To investigate the visibility of margins and surfaces with the combination of TXI and CE for colorectal lesions.METHODS This retrospective study included patients who underwent lower gastrointestinal endoscopy at the Toyoshima Endoscopy Clinic.We extracted polyps that were resected and diagnosed as adenomas or serrated polyps(hyperplastic polyps and sessile serrated lesions)from our endoscopic database.An expert endoscopist performed the lower gastrointestinal endoscopies and observed the lesion using white light imaging(WLI),TXI,CE,and TXI+CE modalities.Indigo carmine dye was used for CE.Three expert endoscopists rated the visibility of the margin and surface patterns in four ranks,from 1 to 4.The primary outcomes were the average visibility scores for the margin and surface patterns based on the WLI,TXI,CE,and TXI+CE observations.Visibility scores between the four modalities were compared by the Kruskal-Wallis and Dunn tests.RESULTS A total of 48 patients with 81 polyps were assessed.The histological subtypes included 50 tubular adenomas,16 hyperplastic polyps,and 15 sessile serrated lesions.The visibility scores for the margins based on WLI,TXI,CE,and TXI+CE were 2.44±0.93,2.90±0.93,3.37±0.74,and 3.75±0.49,respectively.The visibility scores for the surface based on WLI,TXI,CE,and TXI+CE were 2.25±0.80,2.84±0.84,3.12±0.72,and 3.51±0.60,respectively.The visibility scores for the detection and surface on TXI were significantly lower than that on CE but higher than that on WLI(P<0.001).The visibility scores for the margin and surface on TXI+CE were significantly higher than those on CE(P<0.001).In the sub-analysis of adenomas,the visibility for the margin and surface on TXI+CE was significantly better than that on WLI,TXI,and CE(P<0.001).In the sub-analysis of serrated polyps,the visibility for the margin and surface on TXI+CE was also significantly better than that on WLI,TXI,and CE(P<0.001).CONCLUSION TXI+CE enhanced the visibility of the margin and surface compared to WLI,TXI,and CE for colorectal lesions.展开更多
The Neoproterozoic-Lower Paleozoic dolostone gas reservoirs in the Chuanzhong Uplift in Southwestern China contain the mesophase pyrobitumen (pyrobitumen with mesophase). The mesophase in the pyrobitumen is mostly com...The Neoproterozoic-Lower Paleozoic dolostone gas reservoirs in the Chuanzhong Uplift in Southwestern China contain the mesophase pyrobitumen (pyrobitumen with mesophase). The mesophase in the pyrobitumen is mostly composed of a mixture of condensed macromolecule polycyclic aromatic hydrocarbons (PAH), and has been mostly converted to various grain, flow, and domain textures. The volcanic activity nearby the Chuanzhong Uplift may have generated very hot (over 300 °C) hydrothermal fluid, with migration of the fluid into the dolostone reservoir transforming the hydrocarbons in the reservoir into an anisotropic carbon by-product, which formed under high temperature and pressure conditions;over 300 °C and 200 MPa according to fluid inclusion analysis. The high temperature-pressure in reservoir was caused by sudden devolatilization of the hydrocarbons due to hydrothermal heating, which formed the unusual texture of the mesophase. The elliptical mesophase grains (EG), the honeycomb structure of pyrobitumen, and the occurrence of polarized classes of mesophase in single pyrobitumen deposits are all unusual textures. This study investigates the texture development of this pressure-affected pyrobitumen. Observation and study of the mesophase suggest that the class of mesophase in pyrobitumen is determined by temperature, while pressure (assessed from associated fluid inclusions) significantly affected the texture. Analysis of the texture of the pyrobitumen in conjunction with previous thermometry results from methane inclusions suggests that the high class mesophase of the pyrobitumen could be applied as a temperature indicator for geological conditions. Furthermore, the unusual textures of the pyrobitumen including elliptical mesophase grains (EG), the honeycomb structure of pyrobitumen, and the occurrence of polarized classes of mesophase in single pyrobitumen could reflect the abnormal high formation pressure.展开更多
After remanufacturing disassembly,several kinds of friction damages can be found on the mating surface of interference fit.These damages should be repaired and the cost is closely related to the severity of damages.In...After remanufacturing disassembly,several kinds of friction damages can be found on the mating surface of interference fit.These damages should be repaired and the cost is closely related to the severity of damages.Inspired by the excellent performance of surface texture in wear reduction,5 shapes of pit array textures are added to the specimens’surface to study their reduction effect of disassembly damage for interference fit.The results of disassembly experiments show that the order of influence of texture parameters on disassembly damage is as follows:equivalent circle diameter of single texture,texture shape and texture surface density.The influence of equivalent circle diameter of single texture and texture shape are obviously more significant than that of texture surface density.The circular texture with a surface density of 30%and a diameter of 100μm shows an excellent disassembly damage reduction effect because of its perfect ability of abrasive particle collection.And the probability of disassembly damage formation and evolution is also relatively small on this kind of textured surface.Besides,the load-carrying capacity of interference fit with the excellent texture is confirmed by load-carrying capacity experiments.The results show that the load-carrying capacity of the excellent texture surface is increased about 40%compared with that of without texture.This research provides a potential approach to reduce disassembly damage for interference fit.展开更多
Microstructure,texture evolution and strain hardening behaviour of the Mg-1Y and Mg-1Zn(wt%)alloys were investigated under room temperature compression.Microstructural characterization was performed by optical microsc...Microstructure,texture evolution and strain hardening behaviour of the Mg-1Y and Mg-1Zn(wt%)alloys were investigated under room temperature compression.Microstructural characterization was performed by optical microscopy,scanning electron microscopy,electron back scattered diffraction and transmission electron microscopy.The experimental results show that Mg-1Zn alloy exhibits conventional three-stage strain hardening curves,while Mg-1Y alloy exhibits novel six-stage strain hardening curves.For Mg-1Y alloy,rare earth texture leads to weak tensile twinning activity in compression and consequently results in a moderate evolution to<0001>texture.Moreover,inefficient tensile twinning activity and weak slip-twinning interaction give rise to excellent ductility and high hardening capacity but low strain hardening rate.For Mg-1Zn alloy,basal texture leads to pronounced tensile twinning activity in compression and consequently results in rapid evolution to<0001>texture.The intense tensile twinning activity and strong slip-twinning interaction lead to high strain hardening rate but poor ductility and low hardening capacity.展开更多
Deformation twinning is profusely activated in the Mg alloys due to lower critical resolved shear stress(CRSS) compared to the non-basal slip systems(prismatic and pyramidal ) and plays a significant role in texture r...Deformation twinning is profusely activated in the Mg alloys due to lower critical resolved shear stress(CRSS) compared to the non-basal slip systems(prismatic and pyramidal ) and plays a significant role in texture reorientation, grain refinement and enhancement of mechanical performance. Twinning is a sequential process comprising twin nucleation, twin propagation and twin growth, hence several intrinsic and extrinsic parameters that facilitate or suppress the process have been critically reviewed. The dependence of twinning on the grain size, deformation temperature, favorable grain orientation and shear strain have been thoroughly discussed in the context of published literature and an attempt has been made to provide a benchmark conclusive finding based on the majority of works. Furthermore, the subsequent effect of twinning on the mechanical performance of Mg alloys, including ductility, formability and tension-compression asymmetry has been discussed in detail. Lastly, the stability of twins, including stress and thermal stability, is summarized and critical issues related to pertinent bottlenecks have been addressed.展开更多
The effects of different complex shear stress conditions on grain refinement and texture evolution of Mg-13Gd-4Y-2Zn-0.5Zr alloy were investigated.With increasing strain rate,the average grain size of compression-shea...The effects of different complex shear stress conditions on grain refinement and texture evolution of Mg-13Gd-4Y-2Zn-0.5Zr alloy were investigated.With increasing strain rate,the average grain size of compression-shear(CS)and compression-torsion(CT)samples are decreased,and the grain size of dynamic recrystallization(DRX)grains is also decreased.This is because that the precipitation number ofβphases is increased,and the hindering effect on grain growth can be significantly enhanced.The DRX fractions of CS and CT samples are decreased with increased strain rate.The low DRX fraction at high strain rate is related to the insufficient time for grains to nucleate.The DRX process can be promoted by the PSN mechanism of second phases,and the grain growth can be restricted by the pinning effect.At the same time,the texture strength is enhanced as the strain rate increased.Besides,the kinking degree of lamellar long-period stacking ordered(LPSO)phases is increased.Under complex shear stress conditions,non-basal slip,especially pyramidal slip,is easily activated and the texture is deflected greatly.Compared with the CS samples,CT samples have smaller average grain size,higher DRX fraction,and lower texture strength for a certain strain rate.This is because that the equivalent stress of the CT sample is larger,the stress triaxiality is smaller,so more serious dislocations are piled up near grain boundaries and second phases.At the same time,since CT sample was sheared with torsion,the dislocation movement path can be called“rotational dislocation accumulation”,and the longer distribution path of the CT sample is generated,so more sub-grains and low-angle grain boundaries(LAGBs)are formed.Compared with the CS sample,more huge-angle grain boundaries(HAGBs)and DRX grains are formed from grain boundary to grain interior,so better grain refinement effect is achieved.展开更多
Room-temperature(RT) formability is a key factor to broaden the applications of rolled Mg alloy sheets in the industry. However, rolled Mg alloy sheets generally form strong basal texture, where the(0001) poles align ...Room-temperature(RT) formability is a key factor to broaden the applications of rolled Mg alloy sheets in the industry. However, rolled Mg alloy sheets generally form strong basal texture, where the(0001) poles align parallel to the normal direction(ND). This hinders the activation of(0001) [1120] basal slip, limiting the RT formability. Therefore, texture weakening, i.e., the inclination of the(0001) poles from the ND, plays an important role to improve the RT formability. Recrystallization is crucial to control the textural development in Mg,and currently, the texture weakening is commonly achieved using static recrystallization(SRX). However, the type of slipping and twinning,which are activated during rolling, affect the textural features after SRX. It is also demonstrated that shear bands and preferential grain growth are important factors to tailor the texture during SRX. Indeed, dynamic recrystallization(DRX) easily occurs during rolling in Mg, which also affects the final rolling texture, while the effect of DRX on the textural formation is not extensively studied for the development of RT-formable Mg alloy sheets. Therefore, the effect of these factors on the textural development in rolled Mg is reviewed in this manuscript.Additionally, the ideal microstructure and texture for RT-formable Mg alloy sheets are still controversial. The RT-formability includes stretch forming(biaxial tension), bending(plane strain tension), and deep-drawing. In particular, the stretch forming is commonly used to evaluate the RT-formability of rolled Mg. Although the stretch formability has been improved by recent studies, the further improvement is necessary owing to the relatively low formability of rolled Mg compared with that of rolled Fe and Al. Based on the relationship between the microstructure/texture and stretch formability provided in the literature, the design guidance for high stretch formability is proposed in this review.展开更多
Gear power-honing is mainly applied to finish small and medium-sized automotive gears,especially in new energy vehicles.The distinctive curved surface texture greatly improves the noise emission and service life of ho...Gear power-honing is mainly applied to finish small and medium-sized automotive gears,especially in new energy vehicles.The distinctive curved surface texture greatly improves the noise emission and service life of honed gears.The surface texture for honed gear considering the motion path and geometrical shape of abrasive particles has not been investigated.In this paper,the kinematics of the gear honing process is analyzed,and the machining marks produced by the abrasive particles of honing wheel scratching abrasive particles against the workpiece gear are calculated.The tooth surface roughness is modeled considering abrasive particle shapes and material plastic pile-ups.This results in a mathematical model that characterizes the structure of the tooth surface and the orientation of the machining marks.Experiments were used to verify the model,with a maximum relative error of less than 10%when abrasive particles are spherical.Based on this model,the effects of process parameters on the speeds of discrete points on the tooth flank,orientations of machining marks and roughness are discussed.The results show that the shaft angle between the workpiece gear and the honing wheel and the speed of the honing wheel is the main process parameters affecting the surface texture.This research proposes a surface texture model for honed gear,which can provide a theoretical basis for optimizing process parameters for gear power-honing.展开更多
A round 60% of useful energy is wasted in industry, homes, or transportation. Therefore, there has been increasing attention on thermoelectric materials for their ability to harvest waste heat into useful energy. The ...A round 60% of useful energy is wasted in industry, homes, or transportation. Therefore, there has been increasing attention on thermoelectric materials for their ability to harvest waste heat into useful energy. The efficiency of a thermoelectric material depends on its electrical conductivity, Seebeck coefficient, and thermal conductivity in a conflicting manner which results in efficiency optimization challenges. Single crystals and polycrystalline layered materials have comparatively better thermoelectric and mechanical properties in a certain direction. Texture engineering is a special strategy that allows the exploitation of superior material properties in a specific direction. Texturing could be achieved by various sintering and deformation methods, which yield defects improving thermoelectric and mechanical properties. The results show that for(Bi,Sb)_(2)Te_(3), Bi_(2)(Se,Te)_(3), C uSbSe_(2), and SnSe, significant enhancement in the thermoelectric figure of merit is achieved by enhancing the preferred orientation. Texture engineering provides a wide range of strategies to elevate the zT of anisotropic materials to values comparable to those of their single crystalline counterparts.展开更多
The interactive alternating forward extrusion(AFE) method can realize the change of texture type and the weakening of texture strength.Taking AZ31 magnesium alloy as an example, the texture evolution of interactive AF...The interactive alternating forward extrusion(AFE) method can realize the change of texture type and the weakening of texture strength.Taking AZ31 magnesium alloy as an example, the texture evolution of interactive AFE was studied. The results show that all kinds of dynamic recrystallization(DRX) behaviors can weaken the texture to vary degrees. The weakening effect of twinning-induced recrystallization(TDRX)behavior was particularly significant. During the interactive AFE process, the c-axis of most grains rotated under the external force, and tended to be 90° angle with the ED direction, forming a stable fiber texture. In addition, with the increase of loading passes, the starting of {0001} <11–20> basal slip system became more and more difficult. The(10–10) texture formed by {10–10} <11–20> prismatic slip system after sixth passes was the main texture type. With the increase of forming temperature, the starting ability of {10–10} <11–20>prismatic slip systems increased, and the(10–10) texture formed by prismatic slip system above 623 K dominated.展开更多
基金Gobierno de Navarra(Proyectos Estratégicos para Navarra 2020)the FEDER program for the financial support of project NUTRI+。
文摘Dysphagia is commonly associated with malnutrition and an increased choking risk.To overcome these complications,food designed for people with dysphagia should have an appropriate texture and a high nutritional value.In this study,six formulations of a strawberry dessert enriched in protein(calcium caseinate)and fiber(wheat dextrin or inulin)were developed using different hydrocolloids(xanthan gum,carboxymethyl cellulose or modified starch)to provide desirable texture and stability.Nutritional value was calculated and total phenolic content and antioxidant activity of the samples were analyzed.Back-extrusion test,rheological measurements and sensory analysis were performed in refrigerated and frozen samples to characterize their textural and viscoelastic properties.The high content in protein(14.7 g/100 g)and fiber(7.9-8.7 g/100 g)made possible to use the claims“high protein”and“high fiber”.Phytochemicals supplied by strawberries contributed to the antioxidant properties of the dessert.Loss tangent ranged 0.28-0.35 for all the formulations,indicating a weak gel behavior,which could be considered safe to swallow.The formulations with dextrin in combination with carboxymethyl cellulose or xanthan gum seemed to be less susceptible to structural changes during frozen storage.This work provides insights for the development of a nutrient-dense dessert that meets the requirements of people with dysphagia.
文摘Manual investigation of chest radiography(CXR)images by physicians is crucial for effective decision-making in COVID-19 diagnosis.However,the high demand during the pandemic necessitates auxiliary help through image analysis and machine learning techniques.This study presents a multi-threshold-based segmentation technique to probe high pixel intensity regions in CXR images of various pathologies,including normal cases.Texture information is extracted using gray co-occurrence matrix(GLCM)-based features,while vessel-like features are obtained using Frangi,Sato,and Meijering filters.Machine learning models employing Decision Tree(DT)and RandomForest(RF)approaches are designed to categorize CXR images into common lung infections,lung opacity(LO),COVID-19,and viral pneumonia(VP).The results demonstrate that the fusion of texture and vesselbased features provides an effective ML model for aiding diagnosis.The ML model validation using performance measures,including an accuracy of approximately 91.8%with an RF-based classifier,supports the usefulness of the feature set and classifier model in categorizing the four different pathologies.Furthermore,the study investigates the importance of the devised features in identifying the underlying pathology and incorporates histogrambased analysis.This analysis reveals varying natural pixel distributions in CXR images belonging to the normal,COVID-19,LO,and VP groups,motivating the incorporation of additional features such as mean,standard deviation,skewness,and percentile based on the filtered images.Notably,the study achieves a considerable improvement in categorizing COVID-19 from LO,with a true positive rate of 97%,further substantiating the effectiveness of the methodology implemented.
文摘Olympus Corporation developed texture and color enhancement imaging(TXI)as a novel image-enhancing endoscopic technique.This topic highlights a series of hot-topic articles that investigated the efficacy of TXI for gastrointestinal disease identification in the clinical setting.A randomized controlled trial demonstrated improvements in the colorectal adenoma detection rate(ADR)and the mean number of adenomas per procedure(MAP)of TXI compared with those of white-light imaging(WLI)observation(58.7%vs 42.7%,adjusted relative risk 1.35,95%CI:1.17-1.56;1.36 vs 0.89,adjusted incident risk ratio 1.48,95%CI:1.22-1.80,respectively).A cross-over study also showed that the colorectal MAP and ADR in TXI were higher than those in WLI(1.5 vs 1.0,adjusted odds ratio 1.4,95%CI:1.2-1.6;58.2%vs 46.8%,1.5,1.0-2.3,respectively).A randomized controlled trial demonstrated non-inferiority of TXI to narrow-band imaging in the colorectal mean number of adenomas and sessile serrated lesions per procedure(0.29 vs 0.30,difference for non-inferiority-0.01,95%CI:-0.10 to 0.08).A cohort study found that scoring for ulcerative colitis severity using TXI could predict relapse of ulcerative colitis.A cross-sectional study found that TXI improved the gastric cancer detection rate compared to WLI(0.71%vs 0.29%).A cross-sectional study revealed that the sensitivity and accuracy for active Helicobacter pylori gastritis in TXI were higher than those of WLI(69.2%vs 52.5%and 85.3%vs 78.7%,res-pectively).In conclusion,TXI can improve gastrointestinal lesion detection and qualitative diagnosis.Therefore,further studies on the efficacy of TXI in clinical practice are required.
基金Supported by National Natural Science Foundation of China,No.81560278the Health Commission of Guangxi Zhuang Autonomous Region,No.Z-A20221157,No.Z20200953,and No.G201903023.
文摘BACKGROUND Despite continuous changes in treatment methods,the survival rate for advanced hepatocellular carcinoma(HCC)patients remains low,highlighting the importance of diagnostic methods for HCC.AIM To explore the efficacy of texture analysis based on multi-parametric magnetic resonance(MR)imaging(MRI)in predicting microvascular invasion(MVI)in preoperative HCC.METHODS This study included 105 patients with pathologically confirmed HCC,categorized into MVI-positive and MVI-negative groups.We employed Original Data Analysis,Principal Component Analysis,Linear Discriminant Analysis(LDA),and Non-LDA(NDA)for texture analysis using multi-parametric MR images to predict preoperative MVI.The effectiveness of texture analysis was determined using the B11 program of the MaZda4.6 software,with results expressed as the misjudgment rate(MCR).RESULTS Texture analysis using multi-parametric MRI,particularly the MI+PA+F dimensionality reduction method combined with NDA discrimination,demonstrated the most effective prediction of MVI in HCC.Prediction accuracy in the pulse and equilibrium phases was 83.81%.MCRs for the combination of T2-weighted imaging(T2WI),arterial phase,portal venous phase,and equilibrium phase were 22.86%,16.19%,20.95%,and 20.95%,respectively.The area under the curve for predicting MVI positivity was 0.844,with a sensitivity of 77.19%and specificity of 91.67%.CONCLUSION Texture analysis of arterial phase images demonstrated superior predictive efficacy for MVI in HCC compared to T2WI,portal venous,and equilibrium phases.This study provides an objective,non-invasive method for preoperative prediction of MVI,offering a theoretical foundation for the selection of clinical therapy.
基金supported by National Natural Science Foundation of China(52175431)Natural Science Foundation of Tianjin of China(22JCZDJC00730).
文摘Cutting tools are known as the“productivity”of the manufacturing industry,which affects the production efficiency and quality of the workpiece,and has become the focus of research and attention in academia and industry.However,traditional cutting tools often suffer from adhesion or wear during the cutting process,which considerably reduces the cutting efficiency and service life of the tools,and makes it difficult to meet current production requirements.To solve the above problems,scholars have introduced bionics into the tool’s design,applying the microscopic structure of the biological surface to the tool surface to alleviate the tool’s failure.This paper mainly summarizes the research progress of bionic textured cutting tools.Firstly,categorize whether the bionic texture design is inspired by a single organism or multiple organisms.Secondly,it is discussed that the non-smooth surface of the biological surface has five characteristics:hydrophilic lubricity,wear resistance,drag reduction and hydrophobicity,anti-adhesion,and arrangement,and the non-smooth structure of these different characteristics are applied to the surface of the tool is designed with bionic texture.Furtherly,the cutting performance of bionic textured cutting tools is discussed.The anti-friction and wear-resisting mechanism of bionic textured cutting tools is analyzed.Finally,some pending problems and perspectives have been proposed to provide new inspirations for the design of bionic textured cutting tools.
文摘Purpose: This review examines the diagnostic value of transvaginal 3D ultrasound image texture analysis for the diagnosis of uterine adhesions. Materials and Methods: The total clinical data of 53 patients with uterine adhesions diagnosed by hysteroscopy and the imaging data of transvaginal three-dimensional ultrasound from the Second Affiliated Hospital of Chongqing Medical University from June 2022 to August 2023 were retrospectively analysed. Based on hysteroscopic surgical records, patients were divided into two independent groups: normal endometrium and uterine adhesion sites. The samples were divided into a training set and a test set, and the transvaginal 3D ultrasound was used to outline the region of interest (ROI) and extract texture features for normal endometrium and uterine adhesions based on hysteroscopic surgical recordings, the training set data were feature screened and modelled using lasso regression and cross-validation, and the diagnostic efficacy of the model was assessed by applying the subjects’ operating characteristic (ROC) curves. Results: For each group, 290 texture feature parameters were extracted and three higher values were screened out, and the area under the curve of the constructed ultrasonographic scoring model was 0.658 and 0.720 in the training and test sets, respectively. Conclusion Relative clinical value of transvaginal three-dimensional ultrasound image texture analysis for the diagnosis of uterine adhesions.
文摘The purpose of the research is to develop a universal algorithm for partial texture segmentation of any visual images. The main peculiarity of the proposed segmentation procedure is the extraction of only homogeneous fine-grained texture segments present in the images. At first, an initial seed point is found for the largest and most homogeneous segment of the image. This initial seed point of the segment is expanded using a region growing method. Other texture segments of the image are extracted analogously in turn. At the second stage, the procedure of merging the extracted segments belonging to the same texture class is performed. Then, the detected texture segments are input to a neural network with competitive layers which accomplishe</span><span style="font-family:Verdana;">s</span><span style="font-family:""><span style="font-family:Verdana;"> more accurate delineation of the shapes of the extracted texture segments. The proposed segmentation procedure is fully unsupervised, <i></span><i><span style="font-family:Verdana;">i.e.</span></i><span style="font-family:Verdana;"></i>, it does not use any a priori knowledge on either the type of textures or the number of texture segments in the image. The research results in development of the segmentation algorithm realized as a computer program tested in a series of experiments that demonstrate its efficiency on grayscale natural scenes.
基金F.Guo thanks for the support of Chongqing Research Program of Basic Research and Frontier Technology Scientific Research(cstc2019jcyj-msxmX0111)University Innovation Research Group of Chongqing(CXQT20023)+1 种基金Scientific Research Foundation of Chongqing University of Technology(2017ZD35)L.Y.Jiang is sponsored by Science and Technology Research Program of Chongqing Municipal Education Commission(Grant No.KJQN201901127).
文摘Dual-phase Mg-Li alloys sheets were rolled at four different temperatures ranging from liquid nitrogen to 300℃to explore effect of rolling temperature on texture and mechanical properties of the material.Crystal plasticity simulation was utilized to illustrate the influence of slip activity on rolling texture development.The results show that the rolling texture is largely depended on deformation temperature.Unlike commercial Mg alloys,the critical resolved shear stress of basal slip inα-Mg phase of Mg-Li alloy decreased more significantly by increasing temperature compared to that of pyramidal<c+a>slip.Enhancement of basal slip by increasing temperature triggered a decrease of split angle of basal poles for the double-peak texture.Prismaticslip largely enhanced by increasing temperature upon 200℃,which induced a wider orientation spread along the transverse direction.For theβ-Li phase,the promotion of{110}<111>slip system at elevated temperature triggered the enhancement of{211}<110>and{111}<211>texture components.The cryo-rolled sample exhibited the highest strength compared to the others due to a strong hardening behavior at this temperature.A two-stage hardening behavior was observed in these as-rolled dual-phase alloys.Strain transition at phase boundaries could be the reason for appearance of this two-stage hardening.
基金The National Natural Science Foundation of China(Nos.51935014,52165043,52105352,and 82072084)Jiangxi Provincial Natural Science Foundation of China(No.20212BAB214026)+1 种基金The Project of State Key Laboratory of High Performance Complex ManufacturingThe Project of Science and Technology of Jiangxi Provincial Education Department(No.GJJ210835).
文摘Laser powder bed fusion(LPBF)makes it possible for biodegradable zinc(Zn)to be used to produce customized orthopedic implants.In this research,we investigate the impact of laser power and scanning speed on the development of surface quality,relative densification,and texture during LPBF of Zn implants.Increasing laser power was able to decrease melt viscosity and surface tension,which improved the metallurgical bonding between adjacent tracks.Uneven and twisted tracks also became continuous and straight.Scanning speed could controlmolten-pool temperature to restrain grain natural orientation,achieving various crystal orientations and a weakened texture.Importantly,it further avoided the thermal expansion and contraction caused by excessive energy storage and accumulation in the matrix,thus reducing the generation of high-dislocation density.As a result,by selecting a reasonable laser power and scanning speed,the LPBF parts exhibited a flat surface morphology and a high density over 99.5%.Their average hardness,mechanical strength,and elongation reached 50.2 HV,127.8 MPa,and 7.6%,respectively.Additionally,the parts displayed a moderate degradation rate and excellent osteogenic properties.All these results provide a basis for selecting process parameters to optimize the comprehensive properties of LPBF-processed Zn parts for biodegradable applications.
基金funded by Princess Nourah bint Abdulrahman University Researchers Supporting Project Number(PNURSP2023R236),Princess Nourah bint Abdulrahman University,Riyadh,Saudi Arabia.
文摘Around one in eight women will be diagnosed with breast cancer at some time.Improved patient outcomes necessitate both early detection and an accurate diagnosis.Histological images are routinely utilized in the process of diagnosing breast cancer.Methods proposed in recent research only focus on classifying breast cancer on specific magnification levels.No study has focused on using a combined dataset with multiple magnification levels to classify breast cancer.A strategy for detecting breast cancer is provided in the context of this investigation.Histopathology image texture data is used with the wavelet transform in this technique.The proposed method comprises converting histopathological images from Red Green Blue(RGB)to Chrominance of Blue and Chrominance of Red(YCBCR),utilizing a wavelet transform to extract texture information,and classifying the images with Extreme Gradient Boosting(XGBOOST).Furthermore,SMOTE has been used for resampling as the dataset has imbalanced samples.The suggested method is evaluated using 10-fold cross-validation and achieves an accuracy of 99.27%on the BreakHis 1.040X dataset,98.95%on the BreakHis 1.0100X dataset,98.92%on the BreakHis 1.0200X dataset,98.78%on the BreakHis 1.0400X dataset,and 98.80%on the combined dataset.The findings of this study imply that improved breast cancer detection rates and patient outcomes can be achieved by combining wavelet transformation with textural signals to detect breast cancer in histopathology images.
基金Our study was approved by the ethics committee of the Certified Institutional Review Board of the Yoyogi Mental Clinic(certificate number.RKK227).
文摘BACKGROUND Accurate diagnosis and early resection of colorectal polyps are important to prevent the occurrence of colorectal cancer.However,technical factors and morphological factors of polyps itself can lead to missed diagnoses.Imageenhanced endoscopy and chromoendoscopy(CE)have been developed to facilitate an accurate diagnosis.There have been no reports on visibility using a combination of texture and color enhancement imaging(TXI)and CE for colorectal tumors.AIM To investigate the visibility of margins and surfaces with the combination of TXI and CE for colorectal lesions.METHODS This retrospective study included patients who underwent lower gastrointestinal endoscopy at the Toyoshima Endoscopy Clinic.We extracted polyps that were resected and diagnosed as adenomas or serrated polyps(hyperplastic polyps and sessile serrated lesions)from our endoscopic database.An expert endoscopist performed the lower gastrointestinal endoscopies and observed the lesion using white light imaging(WLI),TXI,CE,and TXI+CE modalities.Indigo carmine dye was used for CE.Three expert endoscopists rated the visibility of the margin and surface patterns in four ranks,from 1 to 4.The primary outcomes were the average visibility scores for the margin and surface patterns based on the WLI,TXI,CE,and TXI+CE observations.Visibility scores between the four modalities were compared by the Kruskal-Wallis and Dunn tests.RESULTS A total of 48 patients with 81 polyps were assessed.The histological subtypes included 50 tubular adenomas,16 hyperplastic polyps,and 15 sessile serrated lesions.The visibility scores for the margins based on WLI,TXI,CE,and TXI+CE were 2.44±0.93,2.90±0.93,3.37±0.74,and 3.75±0.49,respectively.The visibility scores for the surface based on WLI,TXI,CE,and TXI+CE were 2.25±0.80,2.84±0.84,3.12±0.72,and 3.51±0.60,respectively.The visibility scores for the detection and surface on TXI were significantly lower than that on CE but higher than that on WLI(P<0.001).The visibility scores for the margin and surface on TXI+CE were significantly higher than those on CE(P<0.001).In the sub-analysis of adenomas,the visibility for the margin and surface on TXI+CE was significantly better than that on WLI,TXI,and CE(P<0.001).In the sub-analysis of serrated polyps,the visibility for the margin and surface on TXI+CE was also significantly better than that on WLI,TXI,and CE(P<0.001).CONCLUSION TXI+CE enhanced the visibility of the margin and surface compared to WLI,TXI,and CE for colorectal lesions.
基金funded by the National Natural Science Foundation of China for Young Scholars(No.41903059).
文摘The Neoproterozoic-Lower Paleozoic dolostone gas reservoirs in the Chuanzhong Uplift in Southwestern China contain the mesophase pyrobitumen (pyrobitumen with mesophase). The mesophase in the pyrobitumen is mostly composed of a mixture of condensed macromolecule polycyclic aromatic hydrocarbons (PAH), and has been mostly converted to various grain, flow, and domain textures. The volcanic activity nearby the Chuanzhong Uplift may have generated very hot (over 300 °C) hydrothermal fluid, with migration of the fluid into the dolostone reservoir transforming the hydrocarbons in the reservoir into an anisotropic carbon by-product, which formed under high temperature and pressure conditions;over 300 °C and 200 MPa according to fluid inclusion analysis. The high temperature-pressure in reservoir was caused by sudden devolatilization of the hydrocarbons due to hydrothermal heating, which formed the unusual texture of the mesophase. The elliptical mesophase grains (EG), the honeycomb structure of pyrobitumen, and the occurrence of polarized classes of mesophase in single pyrobitumen deposits are all unusual textures. This study investigates the texture development of this pressure-affected pyrobitumen. Observation and study of the mesophase suggest that the class of mesophase in pyrobitumen is determined by temperature, while pressure (assessed from associated fluid inclusions) significantly affected the texture. Analysis of the texture of the pyrobitumen in conjunction with previous thermometry results from methane inclusions suggests that the high class mesophase of the pyrobitumen could be applied as a temperature indicator for geological conditions. Furthermore, the unusual textures of the pyrobitumen including elliptical mesophase grains (EG), the honeycomb structure of pyrobitumen, and the occurrence of polarized classes of mesophase in single pyrobitumen could reflect the abnormal high formation pressure.
基金Supported by National Natural Science Foundation of China (Grant No.51405121)。
文摘After remanufacturing disassembly,several kinds of friction damages can be found on the mating surface of interference fit.These damages should be repaired and the cost is closely related to the severity of damages.Inspired by the excellent performance of surface texture in wear reduction,5 shapes of pit array textures are added to the specimens’surface to study their reduction effect of disassembly damage for interference fit.The results of disassembly experiments show that the order of influence of texture parameters on disassembly damage is as follows:equivalent circle diameter of single texture,texture shape and texture surface density.The influence of equivalent circle diameter of single texture and texture shape are obviously more significant than that of texture surface density.The circular texture with a surface density of 30%and a diameter of 100μm shows an excellent disassembly damage reduction effect because of its perfect ability of abrasive particle collection.And the probability of disassembly damage formation and evolution is also relatively small on this kind of textured surface.Besides,the load-carrying capacity of interference fit with the excellent texture is confirmed by load-carrying capacity experiments.The results show that the load-carrying capacity of the excellent texture surface is increased about 40%compared with that of without texture.This research provides a potential approach to reduce disassembly damage for interference fit.
基金Funded by the Beijing Municipal Natural Science Foundation (No.2202004)the National Natural Science Foundation of China (No.51801048)the Basic Research Fund for Newly Enrolled Teachers and the Fund for Distinguished Young Scholars of China Academy of Space Technology。
文摘Microstructure,texture evolution and strain hardening behaviour of the Mg-1Y and Mg-1Zn(wt%)alloys were investigated under room temperature compression.Microstructural characterization was performed by optical microscopy,scanning electron microscopy,electron back scattered diffraction and transmission electron microscopy.The experimental results show that Mg-1Zn alloy exhibits conventional three-stage strain hardening curves,while Mg-1Y alloy exhibits novel six-stage strain hardening curves.For Mg-1Y alloy,rare earth texture leads to weak tensile twinning activity in compression and consequently results in a moderate evolution to<0001>texture.Moreover,inefficient tensile twinning activity and weak slip-twinning interaction give rise to excellent ductility and high hardening capacity but low strain hardening rate.For Mg-1Zn alloy,basal texture leads to pronounced tensile twinning activity in compression and consequently results in rapid evolution to<0001>texture.The intense tensile twinning activity and strong slip-twinning interaction lead to high strain hardening rate but poor ductility and low hardening capacity.
基金supported by the National Research Foundation of Korea (NRF)grant funded by the Korean government (MSIT) (No.2020R1C1C1004434)。
文摘Deformation twinning is profusely activated in the Mg alloys due to lower critical resolved shear stress(CRSS) compared to the non-basal slip systems(prismatic and pyramidal ) and plays a significant role in texture reorientation, grain refinement and enhancement of mechanical performance. Twinning is a sequential process comprising twin nucleation, twin propagation and twin growth, hence several intrinsic and extrinsic parameters that facilitate or suppress the process have been critically reviewed. The dependence of twinning on the grain size, deformation temperature, favorable grain orientation and shear strain have been thoroughly discussed in the context of published literature and an attempt has been made to provide a benchmark conclusive finding based on the majority of works. Furthermore, the subsequent effect of twinning on the mechanical performance of Mg alloys, including ductility, formability and tension-compression asymmetry has been discussed in detail. Lastly, the stability of twins, including stress and thermal stability, is summarized and critical issues related to pertinent bottlenecks have been addressed.
基金supported by Project supported by the Joint Funds of the National Natural Science Foundation of China(Grant No.U20A20230)Natural Science Foundation of Shanxi Province(No.201901D111176)+2 种基金Project supported by the Key R&D program of Shanxi Province(No.2020XXX015)Research Project Supported by Shanxi Scholarship Council of China(2021-127)Graduate Education Innovation Program of Shanxi Province(2022Y579).
文摘The effects of different complex shear stress conditions on grain refinement and texture evolution of Mg-13Gd-4Y-2Zn-0.5Zr alloy were investigated.With increasing strain rate,the average grain size of compression-shear(CS)and compression-torsion(CT)samples are decreased,and the grain size of dynamic recrystallization(DRX)grains is also decreased.This is because that the precipitation number ofβphases is increased,and the hindering effect on grain growth can be significantly enhanced.The DRX fractions of CS and CT samples are decreased with increased strain rate.The low DRX fraction at high strain rate is related to the insufficient time for grains to nucleate.The DRX process can be promoted by the PSN mechanism of second phases,and the grain growth can be restricted by the pinning effect.At the same time,the texture strength is enhanced as the strain rate increased.Besides,the kinking degree of lamellar long-period stacking ordered(LPSO)phases is increased.Under complex shear stress conditions,non-basal slip,especially pyramidal slip,is easily activated and the texture is deflected greatly.Compared with the CS samples,CT samples have smaller average grain size,higher DRX fraction,and lower texture strength for a certain strain rate.This is because that the equivalent stress of the CT sample is larger,the stress triaxiality is smaller,so more serious dislocations are piled up near grain boundaries and second phases.At the same time,since CT sample was sheared with torsion,the dislocation movement path can be called“rotational dislocation accumulation”,and the longer distribution path of the CT sample is generated,so more sub-grains and low-angle grain boundaries(LAGBs)are formed.Compared with the CS sample,more huge-angle grain boundaries(HAGBs)and DRX grains are formed from grain boundary to grain interior,so better grain refinement effect is achieved.
基金supported by JSPS KAKENHI Grant Numbers JP22H00259 and JP22K18900。
文摘Room-temperature(RT) formability is a key factor to broaden the applications of rolled Mg alloy sheets in the industry. However, rolled Mg alloy sheets generally form strong basal texture, where the(0001) poles align parallel to the normal direction(ND). This hinders the activation of(0001) [1120] basal slip, limiting the RT formability. Therefore, texture weakening, i.e., the inclination of the(0001) poles from the ND, plays an important role to improve the RT formability. Recrystallization is crucial to control the textural development in Mg,and currently, the texture weakening is commonly achieved using static recrystallization(SRX). However, the type of slipping and twinning,which are activated during rolling, affect the textural features after SRX. It is also demonstrated that shear bands and preferential grain growth are important factors to tailor the texture during SRX. Indeed, dynamic recrystallization(DRX) easily occurs during rolling in Mg, which also affects the final rolling texture, while the effect of DRX on the textural formation is not extensively studied for the development of RT-formable Mg alloy sheets. Therefore, the effect of these factors on the textural development in rolled Mg is reviewed in this manuscript.Additionally, the ideal microstructure and texture for RT-formable Mg alloy sheets are still controversial. The RT-formability includes stretch forming(biaxial tension), bending(plane strain tension), and deep-drawing. In particular, the stretch forming is commonly used to evaluate the RT-formability of rolled Mg. Although the stretch formability has been improved by recent studies, the further improvement is necessary owing to the relatively low formability of rolled Mg compared with that of rolled Fe and Al. Based on the relationship between the microstructure/texture and stretch formability provided in the literature, the design guidance for high stretch formability is proposed in this review.
基金Supported by National Key Research and Development Plan(Grant No.2020YFE0201000)Chongqing Municipal Special Postdoctoral Science Foundation(Grant No.XmT20200021)Liuzhou Municipal Science and Technology project(Grant No.2021AAB0101).
文摘Gear power-honing is mainly applied to finish small and medium-sized automotive gears,especially in new energy vehicles.The distinctive curved surface texture greatly improves the noise emission and service life of honed gears.The surface texture for honed gear considering the motion path and geometrical shape of abrasive particles has not been investigated.In this paper,the kinematics of the gear honing process is analyzed,and the machining marks produced by the abrasive particles of honing wheel scratching abrasive particles against the workpiece gear are calculated.The tooth surface roughness is modeled considering abrasive particle shapes and material plastic pile-ups.This results in a mathematical model that characterizes the structure of the tooth surface and the orientation of the machining marks.Experiments were used to verify the model,with a maximum relative error of less than 10%when abrasive particles are spherical.Based on this model,the effects of process parameters on the speeds of discrete points on the tooth flank,orientations of machining marks and roughness are discussed.The results show that the shaft angle between the workpiece gear and the honing wheel and the speed of the honing wheel is the main process parameters affecting the surface texture.This research proposes a surface texture model for honed gear,which can provide a theoretical basis for optimizing process parameters for gear power-honing.
基金support from the A*STAR’s Science and Engineering Research CouncilSustainable Hybrid Lighting System for Controlled Environment Agriculture Program: A19D9a0096+1 种基金Singapore MOE AcRF Tier 2 under Grant (No.2018-T2-1-010)funding from the A*STAR’s Career Development Award (No.C210112022)。
文摘A round 60% of useful energy is wasted in industry, homes, or transportation. Therefore, there has been increasing attention on thermoelectric materials for their ability to harvest waste heat into useful energy. The efficiency of a thermoelectric material depends on its electrical conductivity, Seebeck coefficient, and thermal conductivity in a conflicting manner which results in efficiency optimization challenges. Single crystals and polycrystalline layered materials have comparatively better thermoelectric and mechanical properties in a certain direction. Texture engineering is a special strategy that allows the exploitation of superior material properties in a specific direction. Texturing could be achieved by various sintering and deformation methods, which yield defects improving thermoelectric and mechanical properties. The results show that for(Bi,Sb)_(2)Te_(3), Bi_(2)(Se,Te)_(3), C uSbSe_(2), and SnSe, significant enhancement in the thermoelectric figure of merit is achieved by enhancing the preferred orientation. Texture engineering provides a wide range of strategies to elevate the zT of anisotropic materials to values comparable to those of their single crystalline counterparts.
基金supported by National Natural Science Foundation of China (no. 51975166)。
文摘The interactive alternating forward extrusion(AFE) method can realize the change of texture type and the weakening of texture strength.Taking AZ31 magnesium alloy as an example, the texture evolution of interactive AFE was studied. The results show that all kinds of dynamic recrystallization(DRX) behaviors can weaken the texture to vary degrees. The weakening effect of twinning-induced recrystallization(TDRX)behavior was particularly significant. During the interactive AFE process, the c-axis of most grains rotated under the external force, and tended to be 90° angle with the ED direction, forming a stable fiber texture. In addition, with the increase of loading passes, the starting of {0001} <11–20> basal slip system became more and more difficult. The(10–10) texture formed by {10–10} <11–20> prismatic slip system after sixth passes was the main texture type. With the increase of forming temperature, the starting ability of {10–10} <11–20>prismatic slip systems increased, and the(10–10) texture formed by prismatic slip system above 623 K dominated.
