Vertically stacked heterostructures have received extensive attention because of their tunable electronic structures and outstanding optical properties.In this work,we study the structural,electronic,and optical prope...Vertically stacked heterostructures have received extensive attention because of their tunable electronic structures and outstanding optical properties.In this work,we study the structural,electronic,and optical properties of vertically stacked GaS-SnS_(2)heterostructure under the frame of density functional theory.We find that the stacked GaS-SnS_(2)heterostructure is a semiconductor with a suitable indirect band gap of 1.82 eV,exhibiting a type-Ⅱband alignment for easily separating the photo-generated carriers.The electronic properties of GaS-SnS_(2)hetero structure can be effectively tuned by an external strain and electric field.The optical absorption of GaS-SnS_(2)heterostructure is more enhanced than those of the GaS monolayer and SnS_(2)monolayer in the visible light region.Our results suggest that the GaS-SnS_(2)hetero structure is a promising candidate for the photocatalyst and photoelectronic devices in the visible light region.展开更多
The electronic structure and optical property of stacked GaN-WS_(2)heterostructure are explored with HSE06 calculation based on density functional theory.The direct band gap of GaN-WS_(2)heterostructure is 1.993 eV,wh...The electronic structure and optical property of stacked GaN-WS_(2)heterostructure are explored with HSE06 calculation based on density functional theory.The direct band gap of GaN-WS_(2)heterostructure is 1.993 eV,which is obviously a type-II band alignment semiconductor.Furthermore,the optical property of GaN-WS_(2)heterostructure such as absorption coefficient is analyzed.These new findings enable GaN-WS_(2)heterostructure to be promising candidates for photovoltaic cells and electronic devices in visible light.展开更多
In the industrial production of expanded thermoplastic polyurethane (E-TPU) midsoles, the surface defects still rely on manual inspection at present, and the eligibility criteria are uneven. Therefore, this paper prop...In the industrial production of expanded thermoplastic polyurethane (E-TPU) midsoles, the surface defects still rely on manual inspection at present, and the eligibility criteria are uneven. Therefore, this paper proposes an E-TPU midsole surface defect detection method based on machine vision to achieve automatic detection and defect classification. The proposed method is divided into three parts: image preprocessing, block defect detection, and linear defect detection. Image preprocessing uses RGB three channel self-inspection to identify scorch and color pollution. Block defect detection uses superpixel segmentation and background prior mining to determine holes, impurities, and dirt. Linear defect detection uses Gabor filter and Hough transform to detect indentation and convex marks. After image preprocessing, block defect detection and linear defect detection are simultaneously performed by parallel computing. The false positive rate (FPR) of the proposed method in this paper is 8.3%, the false negatives rate (FNR) of the hole is 4.7%, the FNR of indentation is 2.1%, and the running time does not exceed 1.6 s. The test results show that this method can quickly and accurately detect various defects in the E-TPU midsole.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.1186040026)the Incubation Project for High-Level Scientific Research Achievements of Hubei Minzu University,China(Grant No.4205009)the Fund of the Educational Commission of Hubei Province,China(Grant No.T201914)。
文摘Vertically stacked heterostructures have received extensive attention because of their tunable electronic structures and outstanding optical properties.In this work,we study the structural,electronic,and optical properties of vertically stacked GaS-SnS_(2)heterostructure under the frame of density functional theory.We find that the stacked GaS-SnS_(2)heterostructure is a semiconductor with a suitable indirect band gap of 1.82 eV,exhibiting a type-Ⅱband alignment for easily separating the photo-generated carriers.The electronic properties of GaS-SnS_(2)hetero structure can be effectively tuned by an external strain and electric field.The optical absorption of GaS-SnS_(2)heterostructure is more enhanced than those of the GaS monolayer and SnS_(2)monolayer in the visible light region.Our results suggest that the GaS-SnS_(2)hetero structure is a promising candidate for the photocatalyst and photoelectronic devices in the visible light region.
基金Supported by the National Natural Science Foundation of China(No.1186040026)Educational Commission of Hubei Province of China(No.T201914)Incubation Project for HighLevel Scientific Research Achievements of Hubei Minzu University(No.4205009)
文摘The electronic structure and optical property of stacked GaN-WS_(2)heterostructure are explored with HSE06 calculation based on density functional theory.The direct band gap of GaN-WS_(2)heterostructure is 1.993 eV,which is obviously a type-II band alignment semiconductor.Furthermore,the optical property of GaN-WS_(2)heterostructure such as absorption coefficient is analyzed.These new findings enable GaN-WS_(2)heterostructure to be promising candidates for photovoltaic cells and electronic devices in visible light.
文摘In the industrial production of expanded thermoplastic polyurethane (E-TPU) midsoles, the surface defects still rely on manual inspection at present, and the eligibility criteria are uneven. Therefore, this paper proposes an E-TPU midsole surface defect detection method based on machine vision to achieve automatic detection and defect classification. The proposed method is divided into three parts: image preprocessing, block defect detection, and linear defect detection. Image preprocessing uses RGB three channel self-inspection to identify scorch and color pollution. Block defect detection uses superpixel segmentation and background prior mining to determine holes, impurities, and dirt. Linear defect detection uses Gabor filter and Hough transform to detect indentation and convex marks. After image preprocessing, block defect detection and linear defect detection are simultaneously performed by parallel computing. The false positive rate (FPR) of the proposed method in this paper is 8.3%, the false negatives rate (FNR) of the hole is 4.7%, the FNR of indentation is 2.1%, and the running time does not exceed 1.6 s. The test results show that this method can quickly and accurately detect various defects in the E-TPU midsole.
