The effect of revolution on inhomogeneous plastic deformation of HPT processed IF steel was investigated using experimental and simulation approaches. The results indicate that the degree of inhomogeneous plastic defo...The effect of revolution on inhomogeneous plastic deformation of HPT processed IF steel was investigated using experimental and simulation approaches. The results indicate that the degree of inhomogeneous plastic deformation increases as the revolutions increase along the radial direction on the transversal plane of disks. In addition, the hardness and the microstructure distributions verify the trend that the effective strain of the HPT processed disks at the early torsion stage is gradually deformed from the edge to the center with the revolutions increases.展开更多
The hot deformation behavior of FGH96 superalloys at 1070-1170℃ and 5×10^-4-2×10^-1 s^-1 were investigated by means of the isothermal compression tests at a Gleeble-1500 thermal mechanical simulator. The re...The hot deformation behavior of FGH96 superalloys at 1070-1170℃ and 5×10^-4-2×10^-1 s^-1 were investigated by means of the isothermal compression tests at a Gleeble-1500 thermal mechanical simulator. The results show that dynamic recovery acts as the main softening mechanism below 2×10^-3 s^-1, whereas dynamic recrystallization acts as the main softening mechanism above 2× 10^-3 s^-1 during deformation; the temperature increase caused by the deformation and the corresponding softening stress is negligible; the thermal-mechanical constitutive model to describe the hot deformation behavior is given, and the value of the apparent deformation activation energy （Qdef） is determined to be 354.93 kJ/mol.展开更多
A simple chemical-etching approach is used to prepare the silicon carbide quantum dots (QDs). The raw materials of silicon carbide (SiC) with homogeneous nanoparticles fabricated via self-propagating combustion synthe...A simple chemical-etching approach is used to prepare the silicon carbide quantum dots (QDs). The raw materials of silicon carbide (SiC) with homogeneous nanoparticles fabricated via self-propagating combustion synthesis are corroded in mixture etchants of nitric and hydrofluoric acid. After sonication and chromatography in the ultra-gravity field for the etched products, aqueous solution with QDs can be obtained. The microstructure evolution of raw particles and optical properties of QDs were measured. Different organophilic groups on the surface like carboxyl, oxygroup, and hyfroxy were produced in the process of etching. Fluorescent labeling and imaging for living cells of Aureobasidium pulluans were investigated. The results indicated that SiC QDs were not cytotoxic and could stably label due to the conjugation between organophilic groups of QDs and specific protein of cells, it can be utilized for fluorescent imaging and tracking cells with in vivo and long-term-distance. Moreover, mechanism and specificity of mark were also analyzed.展开更多
The inhomogeneous hardness distribution of high pressure torsion (HPT) processed IF steel disks along different directions is investigated. The results indicated that there exists inhomogeneous distribution in HPT pro...The inhomogeneous hardness distribution of high pressure torsion (HPT) processed IF steel disks along different directions is investigated. The results indicated that there exists inhomogeneous distribution in HPT processed IF steel disks, giving lower hardness in the center and higher hardness in the edge regions. However, on the axisymmetrical section testing plane of the disks’ thickness direction, there is a soft zone near the surface of disks. Further results from radius testing plane of different depths from the surface of HPT processed disks show that the inhomogeneity rules of hardness distribution on the radius direction are similar to that on the thickness direction. Compared with the initial state, different stages of HPT (compression and compression + torsion) can both remarkably increase the hardness of IF steel disks. Microstructure investigation results can give a well support to verify the rules of hardness distribution, showing hardly no change of grains in center and sever plastic deformation in edge. The inhomogeneous distribution of stress and strain with the huge friction between anvil and disks in the process of HPT play an important role of hardness and microstructure distribution.展开更多
In order to realize the intelligent identification of maize leaf diseases for accurate prevention and control,this study proposed a maize disease detection method based on improved MobileNet V3-small,using a UAV to co...In order to realize the intelligent identification of maize leaf diseases for accurate prevention and control,this study proposed a maize disease detection method based on improved MobileNet V3-small,using a UAV to collect maize disease images and establish a maize disease dataset in a complex context,and explored the effects of data expansion and migration learning on model recognition accuracy,recall rate,and F1-score instructive evaluative indexes,and the results show that the two approaches of data expansion and migration learning effectively improved the accuracy of the model.The structured compression of MobileNet V3-small bneck layer retains only 6 layers,the expansion multiplier of each layer was redesigned,32-fold fast downsampling was used in the first layer,and the location of the SE module was optimized.The improved model had an average accuracy of 79.52%in the test set,a recall of 77.91%,an F1-score of 78.62%,a model size of 2.36 MB,and a single image detection speed of 9.02 ms.The detection accuracy and speed of the model can meet the requirements of mobile or embedded devices.This study provides technical support for realizing the intelligent detection of maize leaf diseases.展开更多
文摘The effect of revolution on inhomogeneous plastic deformation of HPT processed IF steel was investigated using experimental and simulation approaches. The results indicate that the degree of inhomogeneous plastic deformation increases as the revolutions increase along the radial direction on the transversal plane of disks. In addition, the hardness and the microstructure distributions verify the trend that the effective strain of the HPT processed disks at the early torsion stage is gradually deformed from the edge to the center with the revolutions increases.
基金This work was financially supported by the National Program Committee (No.MKPT-01-127ZD).
文摘The hot deformation behavior of FGH96 superalloys at 1070-1170℃ and 5×10^-4-2×10^-1 s^-1 were investigated by means of the isothermal compression tests at a Gleeble-1500 thermal mechanical simulator. The results show that dynamic recovery acts as the main softening mechanism below 2×10^-3 s^-1, whereas dynamic recrystallization acts as the main softening mechanism above 2× 10^-3 s^-1 during deformation; the temperature increase caused by the deformation and the corresponding softening stress is negligible; the thermal-mechanical constitutive model to describe the hot deformation behavior is given, and the value of the apparent deformation activation energy （Qdef） is determined to be 354.93 kJ/mol.
文摘A simple chemical-etching approach is used to prepare the silicon carbide quantum dots (QDs). The raw materials of silicon carbide (SiC) with homogeneous nanoparticles fabricated via self-propagating combustion synthesis are corroded in mixture etchants of nitric and hydrofluoric acid. After sonication and chromatography in the ultra-gravity field for the etched products, aqueous solution with QDs can be obtained. The microstructure evolution of raw particles and optical properties of QDs were measured. Different organophilic groups on the surface like carboxyl, oxygroup, and hyfroxy were produced in the process of etching. Fluorescent labeling and imaging for living cells of Aureobasidium pulluans were investigated. The results indicated that SiC QDs were not cytotoxic and could stably label due to the conjugation between organophilic groups of QDs and specific protein of cells, it can be utilized for fluorescent imaging and tracking cells with in vivo and long-term-distance. Moreover, mechanism and specificity of mark were also analyzed.
文摘The inhomogeneous hardness distribution of high pressure torsion (HPT) processed IF steel disks along different directions is investigated. The results indicated that there exists inhomogeneous distribution in HPT processed IF steel disks, giving lower hardness in the center and higher hardness in the edge regions. However, on the axisymmetrical section testing plane of the disks’ thickness direction, there is a soft zone near the surface of disks. Further results from radius testing plane of different depths from the surface of HPT processed disks show that the inhomogeneity rules of hardness distribution on the radius direction are similar to that on the thickness direction. Compared with the initial state, different stages of HPT (compression and compression + torsion) can both remarkably increase the hardness of IF steel disks. Microstructure investigation results can give a well support to verify the rules of hardness distribution, showing hardly no change of grains in center and sever plastic deformation in edge. The inhomogeneous distribution of stress and strain with the huge friction between anvil and disks in the process of HPT play an important role of hardness and microstructure distribution.
基金This study was supported by the Fruit Industry Innovation Team Project of the Modern Agricultural Industry Technology System of Shandong Province(SDAIT-06-12)the“Double First-class”Award and subsidy fund project of Shandong Agricultural University(SYL2017X).
文摘In order to realize the intelligent identification of maize leaf diseases for accurate prevention and control,this study proposed a maize disease detection method based on improved MobileNet V3-small,using a UAV to collect maize disease images and establish a maize disease dataset in a complex context,and explored the effects of data expansion and migration learning on model recognition accuracy,recall rate,and F1-score instructive evaluative indexes,and the results show that the two approaches of data expansion and migration learning effectively improved the accuracy of the model.The structured compression of MobileNet V3-small bneck layer retains only 6 layers,the expansion multiplier of each layer was redesigned,32-fold fast downsampling was used in the first layer,and the location of the SE module was optimized.The improved model had an average accuracy of 79.52%in the test set,a recall of 77.91%,an F1-score of 78.62%,a model size of 2.36 MB,and a single image detection speed of 9.02 ms.The detection accuracy and speed of the model can meet the requirements of mobile or embedded devices.This study provides technical support for realizing the intelligent detection of maize leaf diseases.
