In this paper,the occurrence and development mechanism of strain on the cross-section during the wood drying is explored.Therefore,strain regularity on the cross-section of 50 mm thickness elm(Ulmus rubra)board at the...In this paper,the occurrence and development mechanism of strain on the cross-section during the wood drying is explored.Therefore,strain regularity on the cross-section of 50 mm thickness elm(Ulmus rubra)board at the temperature of 40℃and 80℃is detected via digital image correlation technology.Hence,the difference between tangential and radial strain at surface and core layers was denoted.The results showed that strain distribution in the width direction of the board is uneven.Moreover,a large drying shrinkage strain occurs at the near-core layer,while the maximum strain difference reaches 4.08%.Hence,the surface of the board is cracked along the thickness direction.The radial strain of the board is higher than the tangential strain in the early stage of drying,while these strains are reversed in the later stage of drying.The temperature is related to the difference between the tangential and radial strains of the elm board.These differences at the core layer are larger than those of the surface layer.The conducted research results provide a theoretical basis for process optimization.展开更多
Soil desiccation cracking is a prevalent natural phenomenon that poses significant geotechnical and geoenvironmental challenges.Cracks typically initiate at surface defects such as air bubbles,large aggregates,tiny pi...Soil desiccation cracking is a prevalent natural phenomenon that poses significant geotechnical and geoenvironmental challenges.Cracks typically initiate at surface defects such as air bubbles,large aggregates,tiny pits,or uneven surfaces,where localized stress concentrations are readily induced.This study conducted a series of laboratory desiccation tests on slurry samples to investigate the initiation and propagation of desiccation cracks in the presence of varying types and quantities of surface defects.Digital image correlation(DIC)technology was employed to monitor the strain and displacement fields on the soil surface during the desiccation process.The results reveal that strain and displacement data derived from DIC can precisely predict the initiation sites and propagation directions of desiccation cracks.In samples with internal defects,cracks predominantly propagate through the defect,whereas external defects tend to initiate cracks along their edges.In samples with multiple defects,Y-shaped crack patterns generally form initially,followed by T-shaped and straight cracks,driven by the evolving stress field.The dynamic interplay between crack formation and tensile stress redistribution governs the initiation and propagation of desiccation cracks.展开更多
Based on SIMA, the Al-Si alloy semi-solid billets were successfully fabricated by means of strain inducement and isothermal treatment for AlSi9Mg poured in the range of near-liquidus. Through orthogonal test, the effe...Based on SIMA, the Al-Si alloy semi-solid billets were successfully fabricated by means of strain inducement and isothermal treatment for AlSi9Mg poured in the range of near-liquidus. Through orthogonal test, the effects of combination action of near-liquidus casting, strain inducement and isothermal treatment on the morphology of primaryα-Al phase of AlSi9Mg close to eutectic point were investigated, and the optimal match relation between the processing parameters of solidification, deformation parameters of strain inducement, processing parameters of isothermal treatment and microstructure parameters of semi-solid alloy was established. The results indicate that compared with the single near-liquidus casting or SIMA, the microstructure of primaryα-Al phase in AlSi9Mg alloy prepared by compound fabrication process is more homogeneous, with more globular and finer particles, which has average grain size of 40-50 urn and shape factor of greater than 0.75. After holding at 605℃for 30-40 min under a certain cooling rate, increased deformation volume in SIMA benefits the refinement of the grain and the improvement of the morphology for primary phase.展开更多
目的探讨超声自动应变技术参数对射血分数保留心力衰竭(heart failure with preserved ejection fraction,HFpEF)诊断的价值,并构建一个融合临床指标、常规超声参数及自动应变参数的诊断模型,提升HFpEF早期诊断的准确性。方法选取2024年...目的探讨超声自动应变技术参数对射血分数保留心力衰竭(heart failure with preserved ejection fraction,HFpEF)诊断的价值,并构建一个融合临床指标、常规超声参数及自动应变参数的诊断模型,提升HFpEF早期诊断的准确性。方法选取2024年3月至2025年6月于锦州医科大学附属第一医院接受诊疗的313例患者作为研究对象,其中216例确诊的HFpEF患者作为试验组,97例存在危险因素的非HFpEF患者作为对照组。收集所有患者的一般临床资料、常规超声心动图参数及自动应变参数。通过单因素与多因素Logistic回归确定独立影响因素并构建列线图模型,采用受试者操作特征曲线(receiver operating characteristic curve,ROC曲线)、校准曲线、决策曲线及临床影响曲线分析模型性能。结果模型最终纳入7个变量:N末端B型利钠肽、E/e'比值、左心室整体纵向应变、心尖两腔心纵向应变、心尖三腔心纵向应变、心尖四腔心纵向应变和左心房储器期应变。训练集ROC曲线下面积(area under the curve,AUC)为0.972,测试集AUC为0.967。校准曲线亦证实模型拟合优度良好;决策曲线分析显示,模型在全阈值概率下可获净收益。结论基于自动应变技术核心参数,结合临床及常规超声指标构建的诊断模型,对HFp EF具有良好的诊断效能。展开更多
Two-dimensional(2D)semiconductors,especially transition metal dichalcogenides,are the most competitive channel materials for post-silicon electronics due to their great miniaturization potential and advantages of high...Two-dimensional(2D)semiconductors,especially transition metal dichalcogenides,are the most competitive channel materials for post-silicon electronics due to their great miniaturization potential and advantages of high performance and low power consumption.The atomically thick structural advantage of 2D semiconductors also makes their strain tolerance far greater than that of silicon,making them an ideal platform for implementing and expanding strain technology in post-silicon electronics.The strain technology of 2D semiconductors can not only improve the mobility and on-current of a single device but also be more conveniently applied to the integration of 3D gate-all-around and complementary field-effect transistors.In recent years,a series of strain technologies with different characteristics have been developed for 2D semiconductors and transistor devices,including lattice mismatch,thermal expansion coefficient mismatch,substrate-induced stress technology,and process-induced stress.At present,it is necessary to sort out the existing technical foundation and propose strain strategies for 2D semiconductors that better suit industrialization and future 3D integration to meet the needs of high-performance post-silicon electronics.This review takes the mature strained silicon technology as a benchmark,systematically reviews the current strain technology of 2D semiconductors and devices,deeply analyzes the limitations of existing technologies,and proposes the development direction of strain technology for 2D semiconductors suitable for industrial applications and future 3D integration.展开更多
Flexible strain sensor has attracted much attention because of its potential application in human motion detection.In this work,the prepared strain sensor was obtained by encapsulating electrospun carbonized sponge(CS...Flexible strain sensor has attracted much attention because of its potential application in human motion detection.In this work,the prepared strain sensor was obtained by encapsulating electrospun carbonized sponge(CS)with room temperature vulcanized silicone rubber(RTVS).In this paper,the formation mechanism of conductive sponge was studied.Based on the combination of carbonized sponge and RTVS,the strain sensing mechanism and piezoresistive properties are discussed.After research and testing,the CS/RTVS flexible strain sensor has excellent fast response speed and stability,and the maximum strain coefficient of the sensor is 136.27.In this study,the self-developed CS/RTVS sensor was used to monitor the movements of the wrist joint,arm elbow joint and fingers in real time.Research experiments show that CS/RTVS flexible strain sensor has good application prospects in the field of human motion monitoring.展开更多
[ Objective] The aim was to study the fermentation technology of monascus pigment of monascus strains JF-02. [ Method] Single factor experiment was carried out to study the influence of temperature, initial pH, cultur...[ Objective] The aim was to study the fermentation technology of monascus pigment of monascus strains JF-02. [ Method] Single factor experiment was carried out to study the influence of temperature, initial pH, culture time, different agricultural byproduct, and nitrogen source on monascus pigment in fermentation solution. Meanwhile, orthogonal experiment was conducted to get the optimal culture medium and cultivation condition. [ Resultl The optimal gene in the pigment of monascus pigment was 200 g/L of rice, 30 g/L of sweet potato powder, 10 g/L of glucose, 15 g/L of monosodium glutamate, 0.1% of zinc sulfate, and 0.1% of magnesium sulfate. The optimal culture condition was 30 ℃ and initial pH was 6.0. Fermentation time was 72 h, but when 24-L fermentation pot was used, culture time can last to 84 h. [ Condusion] The study provided theoretical basis for the development and application of monascus strains.展开更多
基金supported by the National Natural Science Foundation of China(No.31901242)Heilongjiang Science Foundation Project(No.LH2020C038)National Undergraduate Training Programs for Innovations(No.202110225074)。
文摘In this paper,the occurrence and development mechanism of strain on the cross-section during the wood drying is explored.Therefore,strain regularity on the cross-section of 50 mm thickness elm(Ulmus rubra)board at the temperature of 40℃and 80℃is detected via digital image correlation technology.Hence,the difference between tangential and radial strain at surface and core layers was denoted.The results showed that strain distribution in the width direction of the board is uneven.Moreover,a large drying shrinkage strain occurs at the near-core layer,while the maximum strain difference reaches 4.08%.Hence,the surface of the board is cracked along the thickness direction.The radial strain of the board is higher than the tangential strain in the early stage of drying,while these strains are reversed in the later stage of drying.The temperature is related to the difference between the tangential and radial strains of the elm board.These differences at the core layer are larger than those of the surface layer.The conducted research results provide a theoretical basis for process optimization.
基金supported by the National Natural Science Foundation of China(Grant Nos.42525201,42230710,42407521).
文摘Soil desiccation cracking is a prevalent natural phenomenon that poses significant geotechnical and geoenvironmental challenges.Cracks typically initiate at surface defects such as air bubbles,large aggregates,tiny pits,or uneven surfaces,where localized stress concentrations are readily induced.This study conducted a series of laboratory desiccation tests on slurry samples to investigate the initiation and propagation of desiccation cracks in the presence of varying types and quantities of surface defects.Digital image correlation(DIC)technology was employed to monitor the strain and displacement fields on the soil surface during the desiccation process.The results reveal that strain and displacement data derived from DIC can precisely predict the initiation sites and propagation directions of desiccation cracks.In samples with internal defects,cracks predominantly propagate through the defect,whereas external defects tend to initiate cracks along their edges.In samples with multiple defects,Y-shaped crack patterns generally form initially,followed by T-shaped and straight cracks,driven by the evolving stress field.The dynamic interplay between crack formation and tensile stress redistribution governs the initiation and propagation of desiccation cracks.
基金Project(04044058) supported by the Excellent Youths Science and Technology Foundation of Anhui, China
文摘Based on SIMA, the Al-Si alloy semi-solid billets were successfully fabricated by means of strain inducement and isothermal treatment for AlSi9Mg poured in the range of near-liquidus. Through orthogonal test, the effects of combination action of near-liquidus casting, strain inducement and isothermal treatment on the morphology of primaryα-Al phase of AlSi9Mg close to eutectic point were investigated, and the optimal match relation between the processing parameters of solidification, deformation parameters of strain inducement, processing parameters of isothermal treatment and microstructure parameters of semi-solid alloy was established. The results indicate that compared with the single near-liquidus casting or SIMA, the microstructure of primaryα-Al phase in AlSi9Mg alloy prepared by compound fabrication process is more homogeneous, with more globular and finer particles, which has average grain size of 40-50 urn and shape factor of greater than 0.75. After holding at 605℃for 30-40 min under a certain cooling rate, increased deformation volume in SIMA benefits the refinement of the grain and the improvement of the morphology for primary phase.
文摘目的探讨超声自动应变技术参数对射血分数保留心力衰竭(heart failure with preserved ejection fraction,HFpEF)诊断的价值,并构建一个融合临床指标、常规超声参数及自动应变参数的诊断模型,提升HFpEF早期诊断的准确性。方法选取2024年3月至2025年6月于锦州医科大学附属第一医院接受诊疗的313例患者作为研究对象,其中216例确诊的HFpEF患者作为试验组,97例存在危险因素的非HFpEF患者作为对照组。收集所有患者的一般临床资料、常规超声心动图参数及自动应变参数。通过单因素与多因素Logistic回归确定独立影响因素并构建列线图模型,采用受试者操作特征曲线(receiver operating characteristic curve,ROC曲线)、校准曲线、决策曲线及临床影响曲线分析模型性能。结果模型最终纳入7个变量:N末端B型利钠肽、E/e'比值、左心室整体纵向应变、心尖两腔心纵向应变、心尖三腔心纵向应变、心尖四腔心纵向应变和左心房储器期应变。训练集ROC曲线下面积(area under the curve,AUC)为0.972,测试集AUC为0.967。校准曲线亦证实模型拟合优度良好;决策曲线分析显示,模型在全阈值概率下可获净收益。结论基于自动应变技术核心参数,结合临床及常规超声指标构建的诊断模型,对HFp EF具有良好的诊断效能。
基金the National Natural Science Foundation of China(92163205,52225206,52188101,52303362,62322402,52350301,92463308,52250398,62204012,62304019,52302162,and 52402169)the National Key Research and Development Program of China(2022YFA1203803,2024YFA1212600,and 2023YFF1500401)+6 种基金the special support from the Postdoctoral Science Foundation(2023TQ0007)the Postdoctoral Science Foundation(2023M740031)the Beijing Nova Program(20220484145 and 20230484478)the Young Elite Scientists Sponsorship Program by CAST(2022QNRC001)the Fundamental Research Funds for the Central Universities(FRF-TP-22-004C2,FRF-06500207,and FRF-IDRY-23-038)the State Key Lab for Advanced Metals and Materials(2023-Z05)the Postdoctoral Fellowship Program of CPSF(GZC20230233)。
文摘Two-dimensional(2D)semiconductors,especially transition metal dichalcogenides,are the most competitive channel materials for post-silicon electronics due to their great miniaturization potential and advantages of high performance and low power consumption.The atomically thick structural advantage of 2D semiconductors also makes their strain tolerance far greater than that of silicon,making them an ideal platform for implementing and expanding strain technology in post-silicon electronics.The strain technology of 2D semiconductors can not only improve the mobility and on-current of a single device but also be more conveniently applied to the integration of 3D gate-all-around and complementary field-effect transistors.In recent years,a series of strain technologies with different characteristics have been developed for 2D semiconductors and transistor devices,including lattice mismatch,thermal expansion coefficient mismatch,substrate-induced stress technology,and process-induced stress.At present,it is necessary to sort out the existing technical foundation and propose strain strategies for 2D semiconductors that better suit industrialization and future 3D integration to meet the needs of high-performance post-silicon electronics.This review takes the mature strained silicon technology as a benchmark,systematically reviews the current strain technology of 2D semiconductors and devices,deeply analyzes the limitations of existing technologies,and proposes the development direction of strain technology for 2D semiconductors suitable for industrial applications and future 3D integration.
基金This research is supported by the Science and Technology Department of Jilin Province[20210202128NC]The People’s Republic of China Ministry of Science and Technology[2018YFF0213606-03]Jilin Province Development and Reform Commission[2019C021].
文摘Flexible strain sensor has attracted much attention because of its potential application in human motion detection.In this work,the prepared strain sensor was obtained by encapsulating electrospun carbonized sponge(CS)with room temperature vulcanized silicone rubber(RTVS).In this paper,the formation mechanism of conductive sponge was studied.Based on the combination of carbonized sponge and RTVS,the strain sensing mechanism and piezoresistive properties are discussed.After research and testing,the CS/RTVS flexible strain sensor has excellent fast response speed and stability,and the maximum strain coefficient of the sensor is 136.27.In this study,the self-developed CS/RTVS sensor was used to monitor the movements of the wrist joint,arm elbow joint and fingers in real time.Research experiments show that CS/RTVS flexible strain sensor has good application prospects in the field of human motion monitoring.
基金Supported by Zhenjiang Science and Technology Plan Foundation in Jiangsu Province(NY2008047)
文摘[ Objective] The aim was to study the fermentation technology of monascus pigment of monascus strains JF-02. [ Method] Single factor experiment was carried out to study the influence of temperature, initial pH, culture time, different agricultural byproduct, and nitrogen source on monascus pigment in fermentation solution. Meanwhile, orthogonal experiment was conducted to get the optimal culture medium and cultivation condition. [ Resultl The optimal gene in the pigment of monascus pigment was 200 g/L of rice, 30 g/L of sweet potato powder, 10 g/L of glucose, 15 g/L of monosodium glutamate, 0.1% of zinc sulfate, and 0.1% of magnesium sulfate. The optimal culture condition was 30 ℃ and initial pH was 6.0. Fermentation time was 72 h, but when 24-L fermentation pot was used, culture time can last to 84 h. [ Condusion] The study provided theoretical basis for the development and application of monascus strains.
