Thiswork aims to explore WC-G201 high entropy cemented carbides properties fabricated by spark plasma sintering with AlCoCrFeNiTi_(0.2)and WC as binder phase and hard phase respectively.AlCoCrFeNiTi_(0.2)powder and WC...Thiswork aims to explore WC-G201 high entropy cemented carbides properties fabricated by spark plasma sintering with AlCoCrFeNiTi_(0.2)and WC as binder phase and hard phase respectively.AlCoCrFeNiTi_(0.2)powder and WC powder were mixed at the mass ratio of 5:95,10:90 and 15:85 respectively,and then via SPS at 1300℃for 5min.The results show that the binder phase has good wettability to WC,and with the increase of binder phase content,the hardness of the alloy decreases gradually,fracture toughness increases first and then decreases,the maximum value is 7.88 MPa m1/2.It is estimated that the comprehensive mechanical property of cemented carbides is the best when the binder content is between 5wt%and 10wt%.展开更多
During the renovation process of a certain factory building, significant deflection deformation occurred in the purlins. To identify the reasons for the deformation of the purlins and eliminate potential safety hazard...During the renovation process of a certain factory building, significant deflection deformation occurred in the purlins. To identify the reasons for the deformation of the purlins and eliminate potential safety hazards, a comprehensive structural inspection was carried out on this factory building, the inspection results indicate that the sectional dimension deviations of the measured steel components and the strength of the steel are in line with the design and code requirements. However, the mid-span deflections of some purlin components fail to meet the code requirements. The bearing capacity of the suspended loads under different working conditions was analyzed: Among the 9 hanging load working conditions of the purlins, the bearing capacity of the purlins in 4 working conditions did not meet the code requirements;among the 2 hanging load working conditions of the main frame, the bearing capacity of the frame beam components in 1 working condition did not meet the code requirements, and the deflections of the frame beams in both 2 working conditions did not meet the code requirements. In response to the above results, practical and feasible treatment suggestions were put forward.展开更多
This paper introduces a crack detection example of the prestressed box girder in a certain project. The morphology of the box girder cracks was surveyed and mapped. The length, width, and depth of the cracks were insp...This paper introduces a crack detection example of the prestressed box girder in a certain project. The morphology of the box girder cracks was surveyed and mapped. The length, width, and depth of the cracks were inspected, and the strength and reinforcement configuration of the components were tested. The test results indicate that the strength and reinforcement configuration of the inspected components meet the design requirements. The crack at the end of the top plate of the box girder is a local compressive crack at the anchorage end. The width and length of the crack on the bottom surface of the top plate are not significant, and the depth is relatively shallow. Judging from the crack morphology, this crack is identified as a temperature crack. Additionally, based on the treatment measures for cracks of different widths, the treatment measures for the cracks of the components in this project are derived, providing a reference basis for similar projects in the future.展开更多
This article takes the inspection and appraisal of a certain migratory wooden structure as the backdrop, presents the inspection process of the wooden structure. Upon on-site examination, it was discovered that the co...This article takes the inspection and appraisal of a certain migratory wooden structure as the backdrop, presents the inspection process of the wooden structure. Upon on-site examination, it was discovered that the connection (or node) construction mode of the building was correct. Only local surface flaws were present, and the operation was normal. The stress wave velocity of the randomly inspected wooden columns with surface cracking was close to the critical velocity, suggesting that no obvious cavities or decay defects existed within the measured wooden components. Based on the inspection outcomes, finite element computations were carried out for the wooden structure, arriving at the conclusion that the maximum stress value of the wooden members was smaller than the designed value of wood strength, and the vertical bearing capacity conformed to the requirements of the specifications. And rationally offered relevant treatment suggestions, providing a reference for the inspection and identification of such projects.展开更多
Evaluation of concrete structures in nuclear power plants(NPPs)under long-term irradiation exposure is important to ensure a safe and reliable operation of NPPs during extended service life from 40 to 80 years.In this...Evaluation of concrete structures in nuclear power plants(NPPs)under long-term irradiation exposure is important to ensure a safe and reliable operation of NPPs during extended service life from 40 to 80 years.In this study,a comprehensive multiscale framework of theoretical models was developed to predict the deformation and degradation of mechanical properties of concrete materials subject to long-term neutron irradiation.The generalized self-consistent model and the Mori-Tanaka model were used to characterize the mechanical properties of concrete with multiple phases and multiple scale internal structures.The overall expansion and degradation of mechanical properties of concrete resulted from neutron irradiation as well as elevated temperature were estimated using a composite damage mechanics approach.The neutron radiation-induced degradation,volumetric expansion of aggregates,thermal strains,and shrinkage of cement paste were considered in the comprehensive model.The model can be used as a predictive tool for the effect of long-term neutron irradiation on concrete used in NPPs.展开更多
Nanocrystals(NCs),a colloidal dispersion system formulated with stabilizers,have attracted widespread interest due to their ability to effectively improve the oral bioavailability of poorly water-soluble drugs.The sta...Nanocrystals(NCs),a colloidal dispersion system formulated with stabilizers,have attracted widespread interest due to their ability to effectively improve the oral bioavailability of poorly water-soluble drugs.The stabilizer plays a key role because it can affect the physical stability and even the oral bioavailability of NCs.However,how stabilizers affect the bioavailability of NCs remains unknown.In this study,F68,F127,HPMC,and PVP were each used as a stabilizer to formulate naringenin NCs.The NCs formulated with PVP exhibited excellent release behaviors,cellular uptake,permeability,oral bioavailability,and anti-inflammatory effects.The underlying mechanism is that PVP effectively inhibits the formation of naringenin dimer,which in turn improves the physical stability of the supersaturated solution generated when NC is dissolved.This finding provides insights into the effects of stabilizers on the in vivo performances of NCs and supplies valuable knowledge for the development of poorly water-soluble drugs.展开更多
This paper utilizes three popular semantic segmentation networks,specifically DeepLab v3+,fully convolutional network(FCN),and U-Net to qualitively analyze and identify the key components of cutting slope images in co...This paper utilizes three popular semantic segmentation networks,specifically DeepLab v3+,fully convolutional network(FCN),and U-Net to qualitively analyze and identify the key components of cutting slope images in complex scenes and achieve rapid image-based slope detection.The elements of cutting slope images are divided into 7 categories.In order to determine the best algorithm for pixel level classification of cutting slope images,the networks are compared from three aspects:a)different neural networks,b)different feature extractors,and c)2 different optimization algorithms.It is found that DeepLab v3+with Resnet18 and Sgdm performs best,FCN 32s with Sgdm takes the second,and U-Net with Adam ranks third.This paper also analyzes the segmentation strategies of the three networks in terms of feature map visualization.Results show that the contour generated by DeepLab v3+(combined with Resnet18 and Sgdm)is closest to the ground truth,while the resulting contour of U-Net(combined with Adam)is closest to the input images.展开更多
Susceptibility of patients with chronic obstructive pulmonary disease(COPD)to cardiovascular autonomic dysfunction asso-ciated with exposure to metals in ambient fine particles(PM2.5,particulate matter with aerodynami...Susceptibility of patients with chronic obstructive pulmonary disease(COPD)to cardiovascular autonomic dysfunction asso-ciated with exposure to metals in ambient fine particles(PM2.5,particulate matter with aerodynamic diameter≤2.5µm)remains poorly evidenced.Based on the COPDB(COPD in Beijing)panel study,we aimed to compare the associations of heart rate(HR,an indicator of cardiovascular autonomic function)and exposure to metals in PM2.5 between 53 patients with COPD and 82 healthy controls by using linear mixed-effects models.In all participants,the HR levels were significantly associated with interquartile range increases in the average concentrations of Cr,Zn,and Pb,but the strength of the associations differed by exposure time(from 1.4%for an average 9 days(d)Cr exposure to 3.5%for an average 9 d Zn exposure).HR was positively associated with the average concentrations of PM2.5 and certain metals only in patients with COPD.Associations between HR and exposure to PM2.5,K,Cr,Mn,Ni,Cu,Zn,As,and Se in patients with COPD significantly differed from those in health controls.Furthermore,association between HR and Cr exposure was robust in COPD patients.In conclusion,our findings indicate that COPD could exacerbate difference in HR following exposure to metals in PM2.5.展开更多
文摘Thiswork aims to explore WC-G201 high entropy cemented carbides properties fabricated by spark plasma sintering with AlCoCrFeNiTi_(0.2)and WC as binder phase and hard phase respectively.AlCoCrFeNiTi_(0.2)powder and WC powder were mixed at the mass ratio of 5:95,10:90 and 15:85 respectively,and then via SPS at 1300℃for 5min.The results show that the binder phase has good wettability to WC,and with the increase of binder phase content,the hardness of the alloy decreases gradually,fracture toughness increases first and then decreases,the maximum value is 7.88 MPa m1/2.It is estimated that the comprehensive mechanical property of cemented carbides is the best when the binder content is between 5wt%and 10wt%.
文摘During the renovation process of a certain factory building, significant deflection deformation occurred in the purlins. To identify the reasons for the deformation of the purlins and eliminate potential safety hazards, a comprehensive structural inspection was carried out on this factory building, the inspection results indicate that the sectional dimension deviations of the measured steel components and the strength of the steel are in line with the design and code requirements. However, the mid-span deflections of some purlin components fail to meet the code requirements. The bearing capacity of the suspended loads under different working conditions was analyzed: Among the 9 hanging load working conditions of the purlins, the bearing capacity of the purlins in 4 working conditions did not meet the code requirements;among the 2 hanging load working conditions of the main frame, the bearing capacity of the frame beam components in 1 working condition did not meet the code requirements, and the deflections of the frame beams in both 2 working conditions did not meet the code requirements. In response to the above results, practical and feasible treatment suggestions were put forward.
文摘This paper introduces a crack detection example of the prestressed box girder in a certain project. The morphology of the box girder cracks was surveyed and mapped. The length, width, and depth of the cracks were inspected, and the strength and reinforcement configuration of the components were tested. The test results indicate that the strength and reinforcement configuration of the inspected components meet the design requirements. The crack at the end of the top plate of the box girder is a local compressive crack at the anchorage end. The width and length of the crack on the bottom surface of the top plate are not significant, and the depth is relatively shallow. Judging from the crack morphology, this crack is identified as a temperature crack. Additionally, based on the treatment measures for cracks of different widths, the treatment measures for the cracks of the components in this project are derived, providing a reference basis for similar projects in the future.
文摘This article takes the inspection and appraisal of a certain migratory wooden structure as the backdrop, presents the inspection process of the wooden structure. Upon on-site examination, it was discovered that the connection (or node) construction mode of the building was correct. Only local surface flaws were present, and the operation was normal. The stress wave velocity of the randomly inspected wooden columns with surface cracking was close to the critical velocity, suggesting that no obvious cavities or decay defects existed within the measured wooden components. Based on the inspection outcomes, finite element computations were carried out for the wooden structure, arriving at the conclusion that the maximum stress value of the wooden members was smaller than the designed value of wood strength, and the vertical bearing capacity conformed to the requirements of the specifications. And rationally offered relevant treatment suggestions, providing a reference for the inspection and identification of such projects.
基金sponsored by National Natural Science Foundation of China(Grant Nos.52222808 and 52478323)the University of Chicago Argonne LLC.Subcontract #6F-30823 to University of Colorado Boulder,and Beijing Nova Program(No.20230484437).
文摘Evaluation of concrete structures in nuclear power plants(NPPs)under long-term irradiation exposure is important to ensure a safe and reliable operation of NPPs during extended service life from 40 to 80 years.In this study,a comprehensive multiscale framework of theoretical models was developed to predict the deformation and degradation of mechanical properties of concrete materials subject to long-term neutron irradiation.The generalized self-consistent model and the Mori-Tanaka model were used to characterize the mechanical properties of concrete with multiple phases and multiple scale internal structures.The overall expansion and degradation of mechanical properties of concrete resulted from neutron irradiation as well as elevated temperature were estimated using a composite damage mechanics approach.The neutron radiation-induced degradation,volumetric expansion of aggregates,thermal strains,and shrinkage of cement paste were considered in the comprehensive model.The model can be used as a predictive tool for the effect of long-term neutron irradiation on concrete used in NPPs.
基金by the National Natural Science Foundation of China(No.82173765)the Science Foundation for Outstanding Youth of Liaoning Province(2021-YQ-08)+5 种基金Ningxia Key Research and Invention Program(No.2021BEG02039)Basic Research Projects of Liaoning Provincial Department of Education(2020LFW01)the Career Development Program for Young Teachers in Shenyang Pharmaceutical University(ZQN2019003)the Outstanding Youth Lifting Program in Shenyang Pharmaceutical University(YQ202115)the Natural Science Foundation of Liaoning Province(2020-MS-074)Open Fund of Key Laboratory of Biotechnology and Bioresources Utilization(Dalian Minzu University),Ministry of Education(KF2022005),China.
文摘Nanocrystals(NCs),a colloidal dispersion system formulated with stabilizers,have attracted widespread interest due to their ability to effectively improve the oral bioavailability of poorly water-soluble drugs.The stabilizer plays a key role because it can affect the physical stability and even the oral bioavailability of NCs.However,how stabilizers affect the bioavailability of NCs remains unknown.In this study,F68,F127,HPMC,and PVP were each used as a stabilizer to formulate naringenin NCs.The NCs formulated with PVP exhibited excellent release behaviors,cellular uptake,permeability,oral bioavailability,and anti-inflammatory effects.The underlying mechanism is that PVP effectively inhibits the formation of naringenin dimer,which in turn improves the physical stability of the supersaturated solution generated when NC is dissolved.This finding provides insights into the effects of stabilizers on the in vivo performances of NCs and supplies valuable knowledge for the development of poorly water-soluble drugs.
文摘This paper utilizes three popular semantic segmentation networks,specifically DeepLab v3+,fully convolutional network(FCN),and U-Net to qualitively analyze and identify the key components of cutting slope images in complex scenes and achieve rapid image-based slope detection.The elements of cutting slope images are divided into 7 categories.In order to determine the best algorithm for pixel level classification of cutting slope images,the networks are compared from three aspects:a)different neural networks,b)different feature extractors,and c)2 different optimization algorithms.It is found that DeepLab v3+with Resnet18 and Sgdm performs best,FCN 32s with Sgdm takes the second,and U-Net with Adam ranks third.This paper also analyzes the segmentation strategies of the three networks in terms of feature map visualization.Results show that the contour generated by DeepLab v3+(combined with Resnet18 and Sgdm)is closest to the ground truth,while the resulting contour of U-Net(combined with Adam)is closest to the input images.
基金the National Natural Science Foundation of China(41121004,21190051,41421064 and 81571130100)the National Basic Research Program of China(2015CB553401)。
文摘Susceptibility of patients with chronic obstructive pulmonary disease(COPD)to cardiovascular autonomic dysfunction asso-ciated with exposure to metals in ambient fine particles(PM2.5,particulate matter with aerodynamic diameter≤2.5µm)remains poorly evidenced.Based on the COPDB(COPD in Beijing)panel study,we aimed to compare the associations of heart rate(HR,an indicator of cardiovascular autonomic function)and exposure to metals in PM2.5 between 53 patients with COPD and 82 healthy controls by using linear mixed-effects models.In all participants,the HR levels were significantly associated with interquartile range increases in the average concentrations of Cr,Zn,and Pb,but the strength of the associations differed by exposure time(from 1.4%for an average 9 days(d)Cr exposure to 3.5%for an average 9 d Zn exposure).HR was positively associated with the average concentrations of PM2.5 and certain metals only in patients with COPD.Associations between HR and exposure to PM2.5,K,Cr,Mn,Ni,Cu,Zn,As,and Se in patients with COPD significantly differed from those in health controls.Furthermore,association between HR and Cr exposure was robust in COPD patients.In conclusion,our findings indicate that COPD could exacerbate difference in HR following exposure to metals in PM2.5.
