This paper examines the annual highest daily maximum temperature （DMT） in Korea by using data from 56 weather stations and employing spatial extreme modeling. Our approach is based on max-stable processes （MSP） wi...This paper examines the annual highest daily maximum temperature （DMT） in Korea by using data from 56 weather stations and employing spatial extreme modeling. Our approach is based on max-stable processes （MSP） with Schlather＇s characterization. We divide the country into four regions for a better model fit and identify the best model for each region. We show that regional MSP modeling is more suitable than MSP modeling for the entire region and the pointwise generalized extreme value distribution approach. The advantage of spatial extreme modeling is that more precise and robust return levels and some indices of the highest temperatures can be obtained for observation stations and for locations with no observed data, and so help to determine the effects and assessment of vulnerability as well as to downscale extreme events.展开更多
Shaoyang acupoints are the most frequently used in migraine treatment. However, the central anal- gesic mechanism remains poorly understood. Studies have demonstrated that single stimulus of the verum acupuncture in h...Shaoyang acupoints are the most frequently used in migraine treatment. However, the central anal- gesic mechanism remains poorly understood. Studies have demonstrated that single stimulus of the verum acupuncture in healthy subjects can induce significant connectivity or activity changes in pain- related central networks compared with sham acupuncture. However, these findings are not indicative of the central analgesic mechanism of acupuncture at Shaoyang acupoints. Thus, we recruited 100 migraine sufferers and randomly assigned them into five groups： Shaoyang uncommon acupoint, Shaoyang common acupoint, Yangming uncommon acupoint, non-acupoint control, and blank control groups. Subjects were subjected to evaluation of curative effects and functional MRI prior to and after 10 and 20 acupuncture treatments. All subjects were diagnosed by physicians and enrolled following clinical physical examination. Subjects were observed during 1-4 weeks after inclusion. At the fifth week, the first clinical evaluation and resting functional MRI were conducted. The Shaoyang uncom- mon acupoint, Shaoyang common acupoint, Yangming uncommon acupoint, and non-acupoint control grousp then were treated with acupuncture, five times per week, 20 times in total over 4 weeks. The second and third clinical evaluations and resting functional MRI screenings were conducted following 10 and 20 acupuncture treatments. The blank control group was observed during the 5 to 8 week pe- riod, followed by clinical evaluation and resting functional MRI. The aim of this study was to examine changes in brain functional activity and central networks in subjects with migraine undergoing acu- puncture at Shaoyang uncommon acupoints. This study provides a further explanation of the central analgesic mechanism by which acupuncture at Shaoyang acupoints treats migraine,展开更多
Mast cells (MCs), located ubiquitously near blood vessels, are descended from CD34<sup>+</sup> hematopoietic stem cells. Initially, although their role has been well defined in hypersensitivity reactions, ...Mast cells (MCs), located ubiquitously near blood vessels, are descended from CD34<sup>+</sup> hematopoietic stem cells. Initially, although their role has been well defined in hypersensitivity reactions, the discovery of their sharing in both innate and adaptive immunity has allowed to redefine their crucial interplay on the regulatory function between inflammatory and tumor cells through the release of mediators granule-associated (mainly tryptase and vascular endothelial growth factor). In particular, in several animal and human malignancies it has been well demonstrated that activated c-Kit receptor (c-KitR) and tryptase (an agonist of the proteinase-activated receptor-2) take pivotal part in tumor angiogenesis after the MCs activation, contributing to tumor cells invasion and metastasis. In this review, we focused on crucial MCs density (MCD) role in colorectal cancer (CRC) development and progression angiogenesis-mediated; then, we will analyze the principal studies that have focused on MCD as possible prognostic factor. Finally, we will consider a possible role of MCD as novel therapeutic target mainly by c-KitR tyrosine kinase inhibitors (imatinib, masitinib) and tryptase inhibitors (gabexate and nafamostat mesylate) with the aim to prevent CRC progression.展开更多
For researching the residual stress distribution characteristics of the different large thickness titanium alloy joints by electron beam welding,under heat treatment or non-heat treatment conditions,the changes in res...For researching the residual stress distribution characteristics of the different large thickness titanium alloy joints by electron beam welding,under heat treatment or non-heat treatment conditions,the changes in residual stress distribution characteristics of electron beam welding joints,which thickness is 50 mm,were measured using blind-hole method with local layer-by-layer removal.Effect of post-welding heat treatment on the residual stress distribution also studied.The results show that blind-hole method with local layer-by-layer removal is suitable to measure residual stresses in thick plate,and good to reflect the welded residual stress distribution of large gradient.Residual stress of the test samples in the weld and heat affected zone has high stress level,and internal stress dramatic changes with thickness in this areas.After heat treatment,the samples' stress distributions were significantly reduced.The samples' transverse and longitudinal residual stress are basically the same.Homogenization is obvious.展开更多
The Churchill Falls Hydro Project (called the ‘Upper Churchill Development’) in Labrador [CF(L)Co], was initiated in the late 1960s. At that time, in general, not much attention was paid to the impact of such develo...The Churchill Falls Hydro Project (called the ‘Upper Churchill Development’) in Labrador [CF(L)Co], was initiated in the late 1960s. At that time, in general, not much attention was paid to the impact of such development on the flooding of vegetation, especially forest stands. Both forested and un-forested terrestrial vegetation types were flooded (244,915 ha creating some 74,075 ha of Islands) in the construction of the Main (Smallwood) Reservoir. The effect of flooding and of the constructions, both above and below the Main Reservoir major dyke system, were the subject of our investigation. This paper, the third in a series, reports on the effect of building the dykes during the early phases of construction with the descriptions of the post flooded conditions below the dykes as related to vegetation. The direct disturbances were excavations, fills, and partial and /or total removal of vegetation cover from fabrication platforms and from gravel and rock extraction sites. No new vegetation cover established in the abandoned quarries and gravel pits. However camp sites and manufacturing platforms were subsequently taken over by Alder growth. The indirect disturbances were the flooding of land areas and the de-watering of sections of the original river and lowering of the water level in some lakes. The results of flooding and the de-watering of some nearby areas are illustrated with aerial photographs and figures showing the environmental impact zones and new shore line development. The flooded trees in large and small pools of stagnant water died suddenly and remain in their original place. New vegetation cover developed on the exposed shore lines of de-watered rivers and lakes.展开更多
Using series iteration techniques identities and apply each of these identities in we derive a number of general double series order to deduce several hypergeometric reduction formulas involving the Srivastava-Daoust ...Using series iteration techniques identities and apply each of these identities in we derive a number of general double series order to deduce several hypergeometric reduction formulas involving the Srivastava-Daoust double hypergeometric function. The results presented in this article are based essentially upon the hypergeometric summation theorems of Kummer and Dixon.展开更多
Cu-0.81Cr-0.12Zr-0.05La-0.05Y(mass fraction) alloy was successively subjected to hot rolling, solid solution treatment, cold rolling and aging treatments. Its microstructure, microhardness and electrical conductivity ...Cu-0.81Cr-0.12Zr-0.05La-0.05Y(mass fraction) alloy was successively subjected to hot rolling, solid solution treatment, cold rolling and aging treatments. Its microstructure, microhardness and electrical conductivity at different states were systematically investigated. The as-cast microstructure consists of three phases: Cu matrix, Cr and Cu5 Zr. Zr is completely dissolved into the matrix while partial Cr remains after the solid solution treatment. Aging of the cold-rolled sample makes nanocrystals of Cr and Cu5 Zr precipitate from the matrix, and the microhardness and electrical conductivity rise. A combination of high microhardness(HV 186) and high conductivity(81% IACS) can be obtained by aging the sample at 773 K for 60 min. As the aging temperature increases, the orientation degree of the Cu crystals gradually decreases to zero, but the microstrain in them cannot be eliminated completely owing to the presence of precipitates and dislocations. The Cr precipitates exhibit the N-W orientation relationship with the matrix when the coherence strengthening mechanism plays a main role.展开更多
Hot compression tests were conducted on a homogenized Mg-7Gd-4Y-1Nd-0.5Zr alloy at 450 ℃ and a strain rate of 2 s-1. Dynamic recrystallization （DRX） mechanisms were investigated by optical microscope （OM）, scanni...Hot compression tests were conducted on a homogenized Mg-7Gd-4Y-1Nd-0.5Zr alloy at 450 ℃ and a strain rate of 2 s-1. Dynamic recrystallization （DRX） mechanisms were investigated by optical microscope （OM）, scanning electron microscope （SEM） and transmission electron microscope （TEM） systematically. The crystallographic orientation information is obtained through electron back-scattering diffraction （EBSD）. The result shows that the flow stress firstly reaches a peak rapidly followed by declining to a valley, and then increases gradually again when the alloy is compressed to a strain of-1.88. DRX related to {10]2} tensile twins is extensively observed at small strains, resulting in an evident grain refinement. DRX grains first nucleate along the edges of twin boundaries with about 30~ （0001） off the twin parents. While at large strains, conventional continuous DRX （CDRX） is frequently identified by the formation of small DRX grains along the original grain boundaries and the continuously increasing misorientation from the centre of large original grains to the grain boundaries. Evidence of particle-stimulated nucleation （PSN） is also observed in the present alloy.展开更多
By means of microstructure observation and measurement of creep properties,the high temperature creep behaviors of a single crystal nickel-based superalloy containing Re were investigated.Results show that the single ...By means of microstructure observation and measurement of creep properties,the high temperature creep behaviors of a single crystal nickel-based superalloy containing Re were investigated.Results show that the single crystal nickel-based superalloy containing 4.2% Re possesses a better creep resistance at high temperature.After being crept up to fracture,the various morphologies are displayed in the different areas of the sample,and the γ＇ phase is transformed into the rafted structure along the direction vertical to the applied stress axis in the regions far from the fracture.But the coarsening and twisting extents of the rafted γ＇ phase increase in the regions near the fracture,which is attributed to the occurrence of the larger plastic deformation.In the later stage of creep,the deformation mechanism of the alloy is that the dislocations with [01^-1]and [011] trace features shear into the rafted γ＇ phase.The main/secondary slipping dislocations are alternately activated to twist the rafted γ＇ phase up to the occurrence of creep fracture,which is thought to be the fracture mechanism of the alloy during creep.展开更多
To solve the problems of redundant feature information,the insignificant difference in feature representation,and low recognition accuracy of the fine-grained image,based on the ResNeXt50 model,an MSFResNet network mo...To solve the problems of redundant feature information,the insignificant difference in feature representation,and low recognition accuracy of the fine-grained image,based on the ResNeXt50 model,an MSFResNet network model is proposed by fusing multi-scale feature information.Firstly,a multi-scale feature extraction module is designed to obtain multi-scale information on feature images by using different scales of convolution kernels.Meanwhile,the channel attention mechanism is used to increase the global information acquisition of the network.Secondly,the feature images processed by the multi-scale feature extraction module are fused with the deep feature images through short links to guide the full learning of the network,thus reducing the loss of texture details of the deep network feature images,and improving network generalization ability and recognition accuracy.Finally,the validity of the MSFResNet model is verified using public datasets and applied to wild mushroom identification.Experimental results show that compared with ResNeXt50 network model,the accuracy of the MSFResNet model is improved by 6.01%on the FGVC-Aircraft common dataset.It achieves 99.13%classification accuracy on the wild mushroom dataset,which is 0.47%higher than ResNeXt50.Furthermore,the experimental results of the thermal map show that the MSFResNet model significantly reduces the interference of background information,making the network focus on the location of the main body of wild mushroom,which can effectively improve the accuracy of wild mushroom identification.展开更多
This paper describes the statistical study of important factors that influences transient over voltages resulting from three-phase reclosing of shunt compensated transmission lines. These factors include the model use...This paper describes the statistical study of important factors that influences transient over voltages resulting from three-phase reclosing of shunt compensated transmission lines. These factors include the model used for transmission line representation and the influence of line transposition. Additionally, the over voltages reduction to proper levels depending on the type of control technique are illustrated and analyzed in statistical terms. The evaluation covers three shunt compensation degrees. The digital simulations were performed using the PSCAD/EMTDC software.展开更多
文摘This paper examines the annual highest daily maximum temperature （DMT） in Korea by using data from 56 weather stations and employing spatial extreme modeling. Our approach is based on max-stable processes （MSP） with Schlather＇s characterization. We divide the country into four regions for a better model fit and identify the best model for each region. We show that regional MSP modeling is more suitable than MSP modeling for the entire region and the pointwise generalized extreme value distribution approach. The advantage of spatial extreme modeling is that more precise and robust return levels and some indices of the highest temperatures can be obtained for observation stations and for locations with no observed data, and so help to determine the effects and assessment of vulnerability as well as to downscale extreme events.
基金supported by the National Basic Research Program of China(973 Program),No.2012CB518501the Key Project of the National Natural Science Foundation of China,No.30930112/C190301
文摘Shaoyang acupoints are the most frequently used in migraine treatment. However, the central anal- gesic mechanism remains poorly understood. Studies have demonstrated that single stimulus of the verum acupuncture in healthy subjects can induce significant connectivity or activity changes in pain- related central networks compared with sham acupuncture. However, these findings are not indicative of the central analgesic mechanism of acupuncture at Shaoyang acupoints. Thus, we recruited 100 migraine sufferers and randomly assigned them into five groups： Shaoyang uncommon acupoint, Shaoyang common acupoint, Yangming uncommon acupoint, non-acupoint control, and blank control groups. Subjects were subjected to evaluation of curative effects and functional MRI prior to and after 10 and 20 acupuncture treatments. All subjects were diagnosed by physicians and enrolled following clinical physical examination. Subjects were observed during 1-4 weeks after inclusion. At the fifth week, the first clinical evaluation and resting functional MRI were conducted. The Shaoyang uncom- mon acupoint, Shaoyang common acupoint, Yangming uncommon acupoint, and non-acupoint control grousp then were treated with acupuncture, five times per week, 20 times in total over 4 weeks. The second and third clinical evaluations and resting functional MRI screenings were conducted following 10 and 20 acupuncture treatments. The blank control group was observed during the 5 to 8 week pe- riod, followed by clinical evaluation and resting functional MRI. The aim of this study was to examine changes in brain functional activity and central networks in subjects with migraine undergoing acu- puncture at Shaoyang uncommon acupoints. This study provides a further explanation of the central analgesic mechanism by which acupuncture at Shaoyang acupoints treats migraine,
文摘Mast cells (MCs), located ubiquitously near blood vessels, are descended from CD34<sup>+</sup> hematopoietic stem cells. Initially, although their role has been well defined in hypersensitivity reactions, the discovery of their sharing in both innate and adaptive immunity has allowed to redefine their crucial interplay on the regulatory function between inflammatory and tumor cells through the release of mediators granule-associated (mainly tryptase and vascular endothelial growth factor). In particular, in several animal and human malignancies it has been well demonstrated that activated c-Kit receptor (c-KitR) and tryptase (an agonist of the proteinase-activated receptor-2) take pivotal part in tumor angiogenesis after the MCs activation, contributing to tumor cells invasion and metastasis. In this review, we focused on crucial MCs density (MCD) role in colorectal cancer (CRC) development and progression angiogenesis-mediated; then, we will analyze the principal studies that have focused on MCD as possible prognostic factor. Finally, we will consider a possible role of MCD as novel therapeutic target mainly by c-KitR tyrosine kinase inhibitors (imatinib, masitinib) and tryptase inhibitors (gabexate and nafamostat mesylate) with the aim to prevent CRC progression.
文摘For researching the residual stress distribution characteristics of the different large thickness titanium alloy joints by electron beam welding,under heat treatment or non-heat treatment conditions,the changes in residual stress distribution characteristics of electron beam welding joints,which thickness is 50 mm,were measured using blind-hole method with local layer-by-layer removal.Effect of post-welding heat treatment on the residual stress distribution also studied.The results show that blind-hole method with local layer-by-layer removal is suitable to measure residual stresses in thick plate,and good to reflect the welded residual stress distribution of large gradient.Residual stress of the test samples in the weld and heat affected zone has high stress level,and internal stress dramatic changes with thickness in this areas.After heat treatment,the samples' stress distributions were significantly reduced.The samples' transverse and longitudinal residual stress are basically the same.Homogenization is obvious.
文摘The Churchill Falls Hydro Project (called the ‘Upper Churchill Development’) in Labrador [CF(L)Co], was initiated in the late 1960s. At that time, in general, not much attention was paid to the impact of such development on the flooding of vegetation, especially forest stands. Both forested and un-forested terrestrial vegetation types were flooded (244,915 ha creating some 74,075 ha of Islands) in the construction of the Main (Smallwood) Reservoir. The effect of flooding and of the constructions, both above and below the Main Reservoir major dyke system, were the subject of our investigation. This paper, the third in a series, reports on the effect of building the dykes during the early phases of construction with the descriptions of the post flooded conditions below the dykes as related to vegetation. The direct disturbances were excavations, fills, and partial and /or total removal of vegetation cover from fabrication platforms and from gravel and rock extraction sites. No new vegetation cover established in the abandoned quarries and gravel pits. However camp sites and manufacturing platforms were subsequently taken over by Alder growth. The indirect disturbances were the flooding of land areas and the de-watering of sections of the original river and lowering of the water level in some lakes. The results of flooding and the de-watering of some nearby areas are illustrated with aerial photographs and figures showing the environmental impact zones and new shore line development. The flooded trees in large and small pools of stagnant water died suddenly and remain in their original place. New vegetation cover developed on the exposed shore lines of de-watered rivers and lakes.
文摘Using series iteration techniques identities and apply each of these identities in we derive a number of general double series order to deduce several hypergeometric reduction formulas involving the Srivastava-Daoust double hypergeometric function. The results presented in this article are based essentially upon the hypergeometric summation theorems of Kummer and Dixon.
基金Project(51227001)supported by the National Natural Science Foundation of ChinaProject(2011CB610405)supported by the National Basic Research Program of China
文摘Cu-0.81Cr-0.12Zr-0.05La-0.05Y(mass fraction) alloy was successively subjected to hot rolling, solid solution treatment, cold rolling and aging treatments. Its microstructure, microhardness and electrical conductivity at different states were systematically investigated. The as-cast microstructure consists of three phases: Cu matrix, Cr and Cu5 Zr. Zr is completely dissolved into the matrix while partial Cr remains after the solid solution treatment. Aging of the cold-rolled sample makes nanocrystals of Cr and Cu5 Zr precipitate from the matrix, and the microhardness and electrical conductivity rise. A combination of high microhardness(HV 186) and high conductivity(81% IACS) can be obtained by aging the sample at 773 K for 60 min. As the aging temperature increases, the orientation degree of the Cu crystals gradually decreases to zero, but the microstrain in them cannot be eliminated completely owing to the presence of precipitates and dislocations. The Cr precipitates exhibit the N-W orientation relationship with the matrix when the coherence strengthening mechanism plays a main role.
文摘Hot compression tests were conducted on a homogenized Mg-7Gd-4Y-1Nd-0.5Zr alloy at 450 ℃ and a strain rate of 2 s-1. Dynamic recrystallization （DRX） mechanisms were investigated by optical microscope （OM）, scanning electron microscope （SEM） and transmission electron microscope （TEM） systematically. The crystallographic orientation information is obtained through electron back-scattering diffraction （EBSD）. The result shows that the flow stress firstly reaches a peak rapidly followed by declining to a valley, and then increases gradually again when the alloy is compressed to a strain of-1.88. DRX related to {10]2} tensile twins is extensively observed at small strains, resulting in an evident grain refinement. DRX grains first nucleate along the edges of twin boundaries with about 30~ （0001） off the twin parents. While at large strains, conventional continuous DRX （CDRX） is frequently identified by the formation of small DRX grains along the original grain boundaries and the continuously increasing misorientation from the centre of large original grains to the grain boundaries. Evidence of particle-stimulated nucleation （PSN） is also observed in the present alloy.
基金Project(50571070) supported by the National Natural Science Foundation of China
文摘By means of microstructure observation and measurement of creep properties,the high temperature creep behaviors of a single crystal nickel-based superalloy containing Re were investigated.Results show that the single crystal nickel-based superalloy containing 4.2% Re possesses a better creep resistance at high temperature.After being crept up to fracture,the various morphologies are displayed in the different areas of the sample,and the γ＇ phase is transformed into the rafted structure along the direction vertical to the applied stress axis in the regions far from the fracture.But the coarsening and twisting extents of the rafted γ＇ phase increase in the regions near the fracture,which is attributed to the occurrence of the larger plastic deformation.In the later stage of creep,the deformation mechanism of the alloy is that the dislocations with [01^-1]and [011] trace features shear into the rafted γ＇ phase.The main/secondary slipping dislocations are alternately activated to twist the rafted γ＇ phase up to the occurrence of creep fracture,which is thought to be the fracture mechanism of the alloy during creep.
基金supported by National Natural Science Foundation of China(No.61862037)Lanzhou Jiaotong University Tianyou Innovation Team Project(No.TY202002)。
文摘To solve the problems of redundant feature information,the insignificant difference in feature representation,and low recognition accuracy of the fine-grained image,based on the ResNeXt50 model,an MSFResNet network model is proposed by fusing multi-scale feature information.Firstly,a multi-scale feature extraction module is designed to obtain multi-scale information on feature images by using different scales of convolution kernels.Meanwhile,the channel attention mechanism is used to increase the global information acquisition of the network.Secondly,the feature images processed by the multi-scale feature extraction module are fused with the deep feature images through short links to guide the full learning of the network,thus reducing the loss of texture details of the deep network feature images,and improving network generalization ability and recognition accuracy.Finally,the validity of the MSFResNet model is verified using public datasets and applied to wild mushroom identification.Experimental results show that compared with ResNeXt50 network model,the accuracy of the MSFResNet model is improved by 6.01%on the FGVC-Aircraft common dataset.It achieves 99.13%classification accuracy on the wild mushroom dataset,which is 0.47%higher than ResNeXt50.Furthermore,the experimental results of the thermal map show that the MSFResNet model significantly reduces the interference of background information,making the network focus on the location of the main body of wild mushroom,which can effectively improve the accuracy of wild mushroom identification.
文摘This paper describes the statistical study of important factors that influences transient over voltages resulting from three-phase reclosing of shunt compensated transmission lines. These factors include the model used for transmission line representation and the influence of line transposition. Additionally, the over voltages reduction to proper levels depending on the type of control technique are illustrated and analyzed in statistical terms. The evaluation covers three shunt compensation degrees. The digital simulations were performed using the PSCAD/EMTDC software.
