Emerging two-dimensional(2D)semiconductors are among the most promising materials for ultra-scaled transistors due to their intrinsic atomic-level thickness.As the stacking process advances,the complexity and cost of ...Emerging two-dimensional(2D)semiconductors are among the most promising materials for ultra-scaled transistors due to their intrinsic atomic-level thickness.As the stacking process advances,the complexity and cost of nanosheet field-effect transistors(NSFETs)and complementary FET(CFET)continue to rise.The 1 nm technology node is going to be based on Si-CFET process according to international roadmap for devices and systems(IRDS)(2022,https://irds.ieee.org/),but not publicly confirmed,indicating that more possibilities still exist.The miniaturization advantage of 2D semiconductors motivates us to explore their potential for reducing process costs while matching the performance of next-generation nodes in terms of area,power consumption and speed.In this study,a comprehensive framework is built.A set of MoS2 NSFETs were designed and fabricated to extract the key parameters and performances.And then for benchmarking,the sizes of 2D-NSFET are scaled to a extent that both of the Si-CFET and 2D-NSFET have the same average device footprint.Under these conditions,the frequency of ultra-scaled 2D-NSFET is found to improve by 36%at a fixed power consumption.This work verifies the feasibility of replacing silicon-based CFETs of 1 nm node with 2D-NSFETs and proposes a 2D technology solution for 1 nm nodes,i.e.,“2D eq 1 nm”nodes.At the same time,thanks to the lower characteristic length of 2D semiconductors,the miniaturized 2D-NSFET achieves a 28%frequency increase at a fixed power consumption.Further,developing a standard cell library,these devices obtain a similar trend in 16-bit RISC-V CPUs.This work quantifies and highlights the advantages of 2D semiconductors in advanced nodes,offering new possibilities for the application of 2D semiconductors in high-speed and low-power integrated circuits.展开更多
The underwater X-ray imaging technology development is significant to subaqueous target reconnaissance/detection/identification, subfluvial archaeology,submerged resource exploration, etc. As the core of X-ray imaging...The underwater X-ray imaging technology development is significant to subaqueous target reconnaissance/detection/identification, subfluvial archaeology,submerged resource exploration, etc. As the core of X-ray imaging detection, the scintillator has been plagued by inherent moisture absorption and decomposition, and strict requirements for seamless packaging and waterproofing.Here, we designed a manganese-doped two-dimensional(2D) perovskite scintillator modified by hydrophobic longchain organic amine through the combination of component and doping engineering. The modified perovskites show high water repellency that can be used as an underwater X-ray scintillator. X-ray images of aquatic organisms or other objects with a high spatial resolution of10 lp·mm^(-1) at a big view field(32 mm × 32 mm) were obtained by scintillation screen. This hydrophobic perovskite scintillator based on molecular design is of great promise in underwater X-ray nondestructive testing technology development.展开更多
This paper briefly introduces the characteristics and structure of symbol QR two-dimensional code, a detailed analysis of the image processing method to identify QR code of the whole process, and the bilinear mapping ...This paper briefly introduces the characteristics and structure of symbol QR two-dimensional code, a detailed analysis of the image processing method to identify QR code of the whole process, and the bilinear mapping method is applied to image correction, the final steps of decoding are given. The actual test results show that, the design algorithm has theoretical and practical, this recognition system can correctly read QR code, and has high recognition rate and recognition speed, has practical value and application prospect.展开更多
Let Ф（u ×v, k, Aa, Ac） be the largest possible number of codewords among all two- dimensional （u ×v, k, λa, λc） optical orthogonal codes. A 2-D （u× v, k, λa, λ）-OOC with Ф（u× v, k, λ...Let Ф（u ×v, k, Aa, Ac） be the largest possible number of codewords among all two- dimensional （u ×v, k, λa, λc） optical orthogonal codes. A 2-D （u× v, k, λa, λ）-OOC with Ф（u× v, k, λa, λc） codewords is said to be maximum. In this paper, the number of codewords of a maximum 2-D （u × v, 4, 1, 3）-OOC has been determined.展开更多
River ice is a natural phenomenon in cold regions, influenced by meteorology, geomorphology, and hydraulic conditions. River ice processes involve complex interactions between hydrodynamic, mechanical, and thermal pro...River ice is a natural phenomenon in cold regions, influenced by meteorology, geomorphology, and hydraulic conditions. River ice processes involve complex interactions between hydrodynamic, mechanical, and thermal processes, and they are also influenced by weather and hydrologic conditions. Because natural rivers are serpentine, with bends, narrows, and straight reaches, the commonly-used one-dimensional river ice models and two-dimensional models based on the rectangular Cartesian coordinates are incapable of simulating the physical phenomena accurately. In order to accurately simulate the complicated river geometry and overcome the difficulties of numerical simulation resulting from both complex boundaries and differences between length and width scales, a two-dimensional river ice numerical model based on a boundary-fitted coordinate transformation method was developed. The presented model considers the influence of the frazil ice accumulation under ice cover and the shape of the leading edge of ice cover during the freezing process. The model is capable of determining the velocity field, the distribution of water temperature, the concentration distribution of frazil ice, the transport of floating ice, the progression, stability, and thawing of ice cover, and the transport, accumulation, and erosion of ice under ice cover. A MacCormack scheme was used to solve the equations numerically. The model was validated with field observations from the Hequ Reach of the Yellow River. Comparison of simulation results with field data indicates that the model is capable of simulating the river ice process with high accuracy.展开更多
The history of the development of Chinese telemetry is introduced in the paper. The new telemetry ground station and the new onboard space telemetry system, with the idea of systematic design and the specification, ar...The history of the development of Chinese telemetry is introduced in the paper. The new telemetry ground station and the new onboard space telemetry system, with the idea of systematic design and the specification, are described.展开更多
Objective: to analyze the diagnostic value of two-dimensional ultrasound imaging in peripheral vascular atherosclerosis. Methods: in this study, 100 patients with peripheral vascular atherosclerosis who were treated i...Objective: to analyze the diagnostic value of two-dimensional ultrasound imaging in peripheral vascular atherosclerosis. Methods: in this study, 100 patients with peripheral vascular atherosclerosis who were treated in our hospital from February 2020 to May 2021 were enrolled in the study. All patients were diagnosed by two-dimensional ultrasound imaging technology, and the plaque formation site, imaging manifestations, plaque types and basic diseases were analyzed. Results: for the 100 patients enrolled in this group, the ultrasonic manifestations of the patients mainly included 87 cases of rough intima, 35 cases of thickening, 12 cases of carotid intima thickening and 42 cases of rough intima. 21 plaque formation sites, 62 on the left and 59 on the right;There are 16 origins of internal carotid artery and 13 origins of common carotid artery at 22 bifurcation points and 70 bulbous points of common carotid artery. There were 49 soft spots, 45 hard spots, 4 mixed spots and 2 flat spots. Among the enrolled patients, cerebral infarction and coronary heart disease account for a large proportion, with 43 cases of cerebral infarction, accounting for 43.00%, and 39 cases of coronary heart disease, accounting for 39.00%. Conclusion: two-dimensional ultrasound imaging technology can effectively detect plaque and realize the exact diagnosis of peripheral vascular atherosclerosis.展开更多
基金supported in part by STI 2030-Major Projects under Grant 2022ZD0209200in part by Beijing Natural Science Foundation-Xiaomi Innovation Joint Fund(L233009)+4 种基金in part by National Natural Science Foundation of China under Grant No.62374099in part by the Tsinghua-Toyota Joint Research Fundin part by the Daikin Tsinghua Union Programin part by Independent Research Program of School of Integrated Circuits,Tsinghua UniversityThis work was also sponsored by CIE-Tencent Robotics X Rhino-Bird Focused Research Program.
文摘Emerging two-dimensional(2D)semiconductors are among the most promising materials for ultra-scaled transistors due to their intrinsic atomic-level thickness.As the stacking process advances,the complexity and cost of nanosheet field-effect transistors(NSFETs)and complementary FET(CFET)continue to rise.The 1 nm technology node is going to be based on Si-CFET process according to international roadmap for devices and systems(IRDS)(2022,https://irds.ieee.org/),but not publicly confirmed,indicating that more possibilities still exist.The miniaturization advantage of 2D semiconductors motivates us to explore their potential for reducing process costs while matching the performance of next-generation nodes in terms of area,power consumption and speed.In this study,a comprehensive framework is built.A set of MoS2 NSFETs were designed and fabricated to extract the key parameters and performances.And then for benchmarking,the sizes of 2D-NSFET are scaled to a extent that both of the Si-CFET and 2D-NSFET have the same average device footprint.Under these conditions,the frequency of ultra-scaled 2D-NSFET is found to improve by 36%at a fixed power consumption.This work verifies the feasibility of replacing silicon-based CFETs of 1 nm node with 2D-NSFETs and proposes a 2D technology solution for 1 nm nodes,i.e.,“2D eq 1 nm”nodes.At the same time,thanks to the lower characteristic length of 2D semiconductors,the miniaturized 2D-NSFET achieves a 28%frequency increase at a fixed power consumption.Further,developing a standard cell library,these devices obtain a similar trend in 16-bit RISC-V CPUs.This work quantifies and highlights the advantages of 2D semiconductors in advanced nodes,offering new possibilities for the application of 2D semiconductors in high-speed and low-power integrated circuits.
基金financially supported by the National Natural Science Foundation of China (NSFC)(Nos.22175007 and 21975007)the National Natural Science Foundation for Outstanding Youth Foundation+1 种基金the Fundamental Research Funds for the Central Universities (No.YWF-22-K-101)the National Program for Support of Top-notch Young Professionals and the 111project (Nos.B14009)。
文摘The underwater X-ray imaging technology development is significant to subaqueous target reconnaissance/detection/identification, subfluvial archaeology,submerged resource exploration, etc. As the core of X-ray imaging detection, the scintillator has been plagued by inherent moisture absorption and decomposition, and strict requirements for seamless packaging and waterproofing.Here, we designed a manganese-doped two-dimensional(2D) perovskite scintillator modified by hydrophobic longchain organic amine through the combination of component and doping engineering. The modified perovskites show high water repellency that can be used as an underwater X-ray scintillator. X-ray images of aquatic organisms or other objects with a high spatial resolution of10 lp·mm^(-1) at a big view field(32 mm × 32 mm) were obtained by scintillation screen. This hydrophobic perovskite scintillator based on molecular design is of great promise in underwater X-ray nondestructive testing technology development.
文摘This paper briefly introduces the characteristics and structure of symbol QR two-dimensional code, a detailed analysis of the image processing method to identify QR code of the whole process, and the bilinear mapping method is applied to image correction, the final steps of decoding are given. The actual test results show that, the design algorithm has theoretical and practical, this recognition system can correctly read QR code, and has high recognition rate and recognition speed, has practical value and application prospect.
基金Supported by the National Natural Science Foundation of China(61071221,10831002)
文摘Let Ф（u ×v, k, Aa, Ac） be the largest possible number of codewords among all two- dimensional （u ×v, k, λa, λc） optical orthogonal codes. A 2-D （u× v, k, λa, λ）-OOC with Ф（u× v, k, λa, λc） codewords is said to be maximum. In this paper, the number of codewords of a maximum 2-D （u × v, 4, 1, 3）-OOC has been determined.
基金supported by the National Natural Science Foundation of China(Grant No.50579030)
文摘River ice is a natural phenomenon in cold regions, influenced by meteorology, geomorphology, and hydraulic conditions. River ice processes involve complex interactions between hydrodynamic, mechanical, and thermal processes, and they are also influenced by weather and hydrologic conditions. Because natural rivers are serpentine, with bends, narrows, and straight reaches, the commonly-used one-dimensional river ice models and two-dimensional models based on the rectangular Cartesian coordinates are incapable of simulating the physical phenomena accurately. In order to accurately simulate the complicated river geometry and overcome the difficulties of numerical simulation resulting from both complex boundaries and differences between length and width scales, a two-dimensional river ice numerical model based on a boundary-fitted coordinate transformation method was developed. The presented model considers the influence of the frazil ice accumulation under ice cover and the shape of the leading edge of ice cover during the freezing process. The model is capable of determining the velocity field, the distribution of water temperature, the concentration distribution of frazil ice, the transport of floating ice, the progression, stability, and thawing of ice cover, and the transport, accumulation, and erosion of ice under ice cover. A MacCormack scheme was used to solve the equations numerically. The model was validated with field observations from the Hequ Reach of the Yellow River. Comparison of simulation results with field data indicates that the model is capable of simulating the river ice process with high accuracy.
文摘The history of the development of Chinese telemetry is introduced in the paper. The new telemetry ground station and the new onboard space telemetry system, with the idea of systematic design and the specification, are described.
文摘Objective: to analyze the diagnostic value of two-dimensional ultrasound imaging in peripheral vascular atherosclerosis. Methods: in this study, 100 patients with peripheral vascular atherosclerosis who were treated in our hospital from February 2020 to May 2021 were enrolled in the study. All patients were diagnosed by two-dimensional ultrasound imaging technology, and the plaque formation site, imaging manifestations, plaque types and basic diseases were analyzed. Results: for the 100 patients enrolled in this group, the ultrasonic manifestations of the patients mainly included 87 cases of rough intima, 35 cases of thickening, 12 cases of carotid intima thickening and 42 cases of rough intima. 21 plaque formation sites, 62 on the left and 59 on the right;There are 16 origins of internal carotid artery and 13 origins of common carotid artery at 22 bifurcation points and 70 bulbous points of common carotid artery. There were 49 soft spots, 45 hard spots, 4 mixed spots and 2 flat spots. Among the enrolled patients, cerebral infarction and coronary heart disease account for a large proportion, with 43 cases of cerebral infarction, accounting for 43.00%, and 39 cases of coronary heart disease, accounting for 39.00%. Conclusion: two-dimensional ultrasound imaging technology can effectively detect plaque and realize the exact diagnosis of peripheral vascular atherosclerosis.
