Radio frequency(RF)reflectometry is an effective and sensitive technique for detecting charge signal in semiconductor quantum dots,and its measurement bandwidth can reach the MHz level.However,in accumulation mode dev...Radio frequency(RF)reflectometry is an effective and sensitive technique for detecting charge signal in semiconductor quantum dots,and its measurement bandwidth can reach the MHz level.However,in accumulation mode devices,the presence of parasitic capacitance makes RF reflectometry more difficult.The universal approach is relocating the ion implantation region approximately 10μm from the center of the single-electron transistor(SET)and optimizing the design of the accumulation gates.But,this method puts forward more stringent requirements for micro-nano fabrication processing.Here,we propose a split-gate structure that enables RF reflectometry when the ion-implanted region and the ohmic contact are farther from the SET center.In Si-MOS devices,we employ a split-gate structure to achieve RF detection,with the ion-implanted region located 150μm away from the center of the SET.Within an integration time of 140 nanoseconds,we achieved a readout fidelity exceeding 99.8%and a detection bandwidth of over 2 MHz.This is an alternative solution for micro-nano fabrication processing that cannot achieve ion implantation areas closer to the center of the chip,and is applicable to various silicon-based semiconductor systems.展开更多
The thermal fatigue cracking behavior of high Si-Mo nodular cast iron （NCI） is investigated by means of optical microscope （OM）, scanning electron microscope （SEM） and energy dispersive spectroscope （EDS）, in ...The thermal fatigue cracking behavior of high Si-Mo nodular cast iron （NCI） is investigated by means of optical microscope （OM）, scanning electron microscope （SEM） and energy dispersive spectroscope （EDS）, in order to find a new material used in exhaust manifolds in First Automotive Works （FAW） .Nodular cast irons with silicon content about 4.7% , in combination with up to 1.1% molybdenum , were produced by Jilin University and FAW. The repeated heating / cooling test was performed under cyclic heating at various maximum heating temperatures （Tmax） ranging from 800to 900℃.Experimental results indicate that the thermal fatigue cracking resistance of high Si-Mo NCI decreases with increasing the maximum heating temperature.The periods for crack initiation are 24-36 , 40-50and 70-90times associated with heating temperature of 900 , 850and 800℃ , respectively , when the holding time is about 10min at Tmax.When thermal fatigue cracking occurs , the cracking always initiates at the bigger surface of specimen.The major positions of cracks propagation are generally at the eutectic oxide boundary region and the region of the graphite disappearance.At the same time , the oxidation may accelerate crack initiation and propagation.On the other hand , micro-crack number varied from large to little because of shielding effect.As exhaust manifolds , the reasonable working temperature of high Si-Mo NCI is no more than 840℃ by test and analysis.展开更多
Si-Mo vermicular iron is an ideal material for exhaust manifold that works in high temperature and thermal cycle conditions because its properties of thermal fatigue resistance and thermal distortion resistance are si...Si-Mo vermicular iron is an ideal material for exhaust manifold that works in high temperature and thermal cycle conditions because its properties of thermal fatigue resistance and thermal distortion resistance are significantly better than that of gray cast iron and nodular iron. This paper explains that the vermicularity of Si-Mo vermicular iron is better to be controlled approximately to 50% for the applications of exhaust manifold castings, and generalizes the successful experience of vermicularizing technique that uses sandwich (pour over) process combining with cored-wire injection in trough process together, and uses rare earths-magnesium-silicon as vermicularizing alloy in Disa high speed molding line and automatic plug rod air pressure pouring furnace. In addition, this paper also describes the method to solve the shrinkage hole and porosity defects in the exhaust manifold production.展开更多
A coating of composition Si-40Mo (wt pct) was prepared by fused slurry coating method on the two-dimensional carbon/carbon (2D-C/C) composite to improve oxidation resistance. In the procedure of the fabrication, pure ...A coating of composition Si-40Mo (wt pct) was prepared by fused slurry coating method on the two-dimensional carbon/carbon (2D-C/C) composite to improve oxidation resistance. In the procedure of the fabrication, pure St slurry inner layer in the pre-coating was necessary to apply because of infiltration of liquid Si into the substrate during the sintering. The coating consists of Si continuous phase and MoSi2 particles. In addition, the infiltration of Si into the substrate and the SiC reaction layer between the coating and the C/C composite were observed. Oxidation behavior of coated and uncoated C/C composites was studied in cyclic mode. The oxidation resistance and the thermal shock resistance of the Si-Mo fused slurry coating were quite excellent at 1370℃.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.92165207,12474490,12034018,and 92265113)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0302300)the USTC Tang Scholarship.
文摘Radio frequency(RF)reflectometry is an effective and sensitive technique for detecting charge signal in semiconductor quantum dots,and its measurement bandwidth can reach the MHz level.However,in accumulation mode devices,the presence of parasitic capacitance makes RF reflectometry more difficult.The universal approach is relocating the ion implantation region approximately 10μm from the center of the single-electron transistor(SET)and optimizing the design of the accumulation gates.But,this method puts forward more stringent requirements for micro-nano fabrication processing.Here,we propose a split-gate structure that enables RF reflectometry when the ion-implanted region and the ohmic contact are farther from the SET center.In Si-MOS devices,we employ a split-gate structure to achieve RF detection,with the ion-implanted region located 150μm away from the center of the SET.Within an integration time of 140 nanoseconds,we achieved a readout fidelity exceeding 99.8%and a detection bandwidth of over 2 MHz.This is an alternative solution for micro-nano fabrication processing that cannot achieve ion implantation areas closer to the center of the chip,and is applicable to various silicon-based semiconductor systems.
基金Item Sponsored by Science and Technology Supporting Project of Jilin Province of China (2007301)
文摘The thermal fatigue cracking behavior of high Si-Mo nodular cast iron （NCI） is investigated by means of optical microscope （OM）, scanning electron microscope （SEM） and energy dispersive spectroscope （EDS）, in order to find a new material used in exhaust manifolds in First Automotive Works （FAW） .Nodular cast irons with silicon content about 4.7% , in combination with up to 1.1% molybdenum , were produced by Jilin University and FAW. The repeated heating / cooling test was performed under cyclic heating at various maximum heating temperatures （Tmax） ranging from 800to 900℃.Experimental results indicate that the thermal fatigue cracking resistance of high Si-Mo NCI decreases with increasing the maximum heating temperature.The periods for crack initiation are 24-36 , 40-50and 70-90times associated with heating temperature of 900 , 850and 800℃ , respectively , when the holding time is about 10min at Tmax.When thermal fatigue cracking occurs , the cracking always initiates at the bigger surface of specimen.The major positions of cracks propagation are generally at the eutectic oxide boundary region and the region of the graphite disappearance.At the same time , the oxidation may accelerate crack initiation and propagation.On the other hand , micro-crack number varied from large to little because of shielding effect.As exhaust manifolds , the reasonable working temperature of high Si-Mo NCI is no more than 840℃ by test and analysis.
文摘Si-Mo vermicular iron is an ideal material for exhaust manifold that works in high temperature and thermal cycle conditions because its properties of thermal fatigue resistance and thermal distortion resistance are significantly better than that of gray cast iron and nodular iron. This paper explains that the vermicularity of Si-Mo vermicular iron is better to be controlled approximately to 50% for the applications of exhaust manifold castings, and generalizes the successful experience of vermicularizing technique that uses sandwich (pour over) process combining with cored-wire injection in trough process together, and uses rare earths-magnesium-silicon as vermicularizing alloy in Disa high speed molding line and automatic plug rod air pressure pouring furnace. In addition, this paper also describes the method to solve the shrinkage hole and porosity defects in the exhaust manifold production.
文摘A coating of composition Si-40Mo (wt pct) was prepared by fused slurry coating method on the two-dimensional carbon/carbon (2D-C/C) composite to improve oxidation resistance. In the procedure of the fabrication, pure St slurry inner layer in the pre-coating was necessary to apply because of infiltration of liquid Si into the substrate during the sintering. The coating consists of Si continuous phase and MoSi2 particles. In addition, the infiltration of Si into the substrate and the SiC reaction layer between the coating and the C/C composite were observed. Oxidation behavior of coated and uncoated C/C composites was studied in cyclic mode. The oxidation resistance and the thermal shock resistance of the Si-Mo fused slurry coating were quite excellent at 1370℃.
