Scientific and commercial advances have set high requirements for wearable electronics. However, the power supply, breathability, and mass production of wearable electronics still have many challenges that need to be ...Scientific and commercial advances have set high requirements for wearable electronics. However, the power supply, breathability, and mass production of wearable electronics still have many challenges that need to be overcome. In this study, a self-powered nanofiber-based triboelectric sensor （SNTS） was fabricated by batch-scale fabrication technologies using electrospinning and screen-printing for health monitoring via respiratory monitoring. Typically, an arch structural SNTS is assembled by a nanofiber membrane and a Ag nanoparticle electrode. The pile of nanofibers and the conductive network of Ag nanoparticles ensure a gas channel across the whole device. The gas permeability of the SNTS was as high as 6.16 mm/s, which has overwhelming advantages when compared with commonly used wearable devices composed of air-tight cast films. Due to the softness of the nanofiber membrane, the SNTS showed excellent electronic output performance irrespective of whether it was bent, twisted, or folded. The superior properties, such as breathability, skin-friendliness, self-power, and batch fabrication of SNTS offer huge potential for their application in healthcare monitoring and multifunctional intelligent systems.展开更多
In order to further clarify and improve the working performance of separating cleaner for flax threshing materials,and study the migration law and characteristics of components of flax threshing materials during separ...In order to further clarify and improve the working performance of separating cleaner for flax threshing materials,and study the migration law and characteristics of components of flax threshing materials during separating and cleaning,in this paper,a gas-solid coupling simulation model was established on the separation cleaner for flax threshing materials and a numerical simulation was carried out on the separating and cleaning process.Simulation results showed that,the separating and cleaning effect of the components of flax threshing materials was good under the air-and-screen gas-solid coupling flow field.Meanwhile,the form distribution and the vector distribution of air volume and velocity of flax threshing materials in the air-and-screen devices were obtained.By referring to the migration trajectories of the flax threshing materials in the vibration sieve device,double channel residue collection device and dust absorber,the volume variation,motion trajectories and variation of migration velocity of the components of flax threshing materials over time in different regions were explored.Verification test results showed that,the content impurity rate of the separation cleaner for flax threshing materials was 2.06%,and loss rate in cleaning was 3.08%.Compared with simulation results,the verification test results were 1.23%and 0.42%higher,showing that the established discrete element model on the flax threshing materials and parameter setting were basically feasible.The verification test also verified the correctness of the simulation results of the separating and cleaning process of the flax threshing materials based on gas-solid coupling theory and the feasibility of the research method.展开更多
基金The authors are thankful for support from the National Key R＆D Project from Ministry of Science and Technology （Nos. 2016YFA0202702, 2016YFA0202703, and 2016YFA0202704）, National Natural Science Foundation of China （Nos. 21703010, 21274006, and 51503005）, and the Programs for Beijing Science and Technology Leading Talent （No. Z16111000490000）.
文摘Scientific and commercial advances have set high requirements for wearable electronics. However, the power supply, breathability, and mass production of wearable electronics still have many challenges that need to be overcome. In this study, a self-powered nanofiber-based triboelectric sensor （SNTS） was fabricated by batch-scale fabrication technologies using electrospinning and screen-printing for health monitoring via respiratory monitoring. Typically, an arch structural SNTS is assembled by a nanofiber membrane and a Ag nanoparticle electrode. The pile of nanofibers and the conductive network of Ag nanoparticles ensure a gas channel across the whole device. The gas permeability of the SNTS was as high as 6.16 mm/s, which has overwhelming advantages when compared with commonly used wearable devices composed of air-tight cast films. Due to the softness of the nanofiber membrane, the SNTS showed excellent electronic output performance irrespective of whether it was bent, twisted, or folded. The superior properties, such as breathability, skin-friendliness, self-power, and batch fabrication of SNTS offer huge potential for their application in healthcare monitoring and multifunctional intelligent systems.
基金The authors acknowledge that this work was financially supported by China Agriculture Research System of MOF and MARA(Grant No.CARS-14-1-28)Fuxi Young Talents Fund of Gansu Agricultural University(Grant No.Gaufx-03Y01)Key Research and Development Project of Gansu Province(Grant No.20YF3WA019).
文摘In order to further clarify and improve the working performance of separating cleaner for flax threshing materials,and study the migration law and characteristics of components of flax threshing materials during separating and cleaning,in this paper,a gas-solid coupling simulation model was established on the separation cleaner for flax threshing materials and a numerical simulation was carried out on the separating and cleaning process.Simulation results showed that,the separating and cleaning effect of the components of flax threshing materials was good under the air-and-screen gas-solid coupling flow field.Meanwhile,the form distribution and the vector distribution of air volume and velocity of flax threshing materials in the air-and-screen devices were obtained.By referring to the migration trajectories of the flax threshing materials in the vibration sieve device,double channel residue collection device and dust absorber,the volume variation,motion trajectories and variation of migration velocity of the components of flax threshing materials over time in different regions were explored.Verification test results showed that,the content impurity rate of the separation cleaner for flax threshing materials was 2.06%,and loss rate in cleaning was 3.08%.Compared with simulation results,the verification test results were 1.23%and 0.42%higher,showing that the established discrete element model on the flax threshing materials and parameter setting were basically feasible.The verification test also verified the correctness of the simulation results of the separating and cleaning process of the flax threshing materials based on gas-solid coupling theory and the feasibility of the research method.
